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Open AccessArticle Ultra High Electrical Performance of Nano Nickel Oxide and Polyaniline Composite Materials
Polymers 2017, 9(7), 288; doi:10.3390/polym9070288
Received: 7 June 2017 / Revised: 10 July 2017 / Accepted: 18 July 2017 / Published: 20 July 2017
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Abstract
The cooperative effects between the PANI (polyaniline)/nano-NiO (nano nickel oxide) composite electrode material and redox electrolytes (potassium iodide, KI) for supercapacitor applications was firstly discussed in this article, providing a novel method to prepare nano-NiO by using β-cyelodextrin (β-CD) as the template agent.
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The cooperative effects between the PANI (polyaniline)/nano-NiO (nano nickel oxide) composite electrode material and redox electrolytes (potassium iodide, KI) for supercapacitor applications was firstly discussed in this article, providing a novel method to prepare nano-NiO by using β-cyelodextrin (β-CD) as the template agent. The experimental results revealed that the composite electrode processed a high specific capacitance (2122.75 F·g−1 at 0.1 A·g−1 in 0.05 M KI electrolyte solution), superior energy density (64.05 Wh·kg−1 at 0.2 A·g−1 in the two-electrode system) and excellent cycle performance (86% capacitance retention after 1000 cycles at 1.5 A·g−1). All those ultra-high electrical performances owe to the KI active material in the electrolyte and the PANI coated nano-NiO structure. Full article
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Open AccessArticle Associations of PM2.5 and Black Carbon with Hospital Emergency Room Visits during Heavy Haze Events: A Case Study in Beijing, China
Int. J. Environ. Res. Public Health 2017, 14(7), 725; doi:10.3390/ijerph14070725
Received: 29 March 2017 / Revised: 29 June 2017 / Accepted: 30 June 2017 / Published: 5 July 2017
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Abstract
In January 2013, severe haze events over northeastern China sparked substantial health concerns. This study explores the associations of fine particulate matter less than 2.5 μm (PM2.5) and black carbon (BC) with hospital emergency room visits (ERVs) during a haze season
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In January 2013, severe haze events over northeastern China sparked substantial health concerns. This study explores the associations of fine particulate matter less than 2.5 μm (PM2.5) and black carbon (BC) with hospital emergency room visits (ERVs) during a haze season in Beijing. During that period, daily counts of ERVs for respiratory, cardiovascular and ocular diseases were obtained from a Level-3A hospital in Beijing from 1 December 2012 to 28 February 2013, and associations of which with PM2.5 and BC were estimated by time-stratified case-crossover analysis in single- and two-pollutant models. We found a 27.5% (95% confidence interval (CI): 13.0, 43.9%) increase in respiratory ERV (lag02), a 19.4% (95% CI: 2.5, 39.0%) increase in cardiovascular ERV (lag0), and a 12.6% (95% CI: 0.0, 26.7%) increase in ocular ERV (lag0) along with an interquartile range (IQR) increase in the PM2.5. An IQR increase of BC was associated with 27.6% (95% CI: 9.6, 48.6%) (lag02), 18.8% (95% CI: 1.4, 39.2%) (lag0) and 11.8% (95% CI: −1.4, 26.8%) (lag0) increases for changes in these same health outcomes respectively. Estimated associations were consistent after adjusting SO2 or NO2 in two-pollutant models. This study provides evidence that improving air quality and reducing haze days would greatly benefit the population health. Full article
(This article belongs to the Section Environmental Health)
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Open AccessArticle Screening and Identification of the Metabolites in Rat Plasma and Urine after Oral Administration of Areca catechu L. Nut Extract by Ultra-High-Pressure Liquid Chromatography Coupled with Linear Ion Trap–Orbitrap Tandem Mass Spectrometry
Molecules 2017, 22(6), 1026; doi:10.3390/molecules22061026
Received: 6 June 2017 / Revised: 18 June 2017 / Accepted: 19 June 2017 / Published: 21 June 2017
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Abstract
Areca catechu L. nut, a well-known toxic traditional herbal medicine, has been widely used to treat various diseases in China and many other Asian countries for centuries. However, to date the in vivo absorption and metabolism of its multiple bioactive or toxic components
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Areca catechu L. nut, a well-known toxic traditional herbal medicine, has been widely used to treat various diseases in China and many other Asian countries for centuries. However, to date the in vivo absorption and metabolism of its multiple bioactive or toxic components still remain unclear. In this study, liquid chromatography coupled with tandem mass spectrometry was used to analyze the major components and their metabolites in rat plasma and urine after oral administration of Areca catechu L. nut extract (ACNE). A total of 12 compounds, including 6 alkaloids, 3 tannins and 3 amino acids, were confirmed or tentatively identified from ACNE. In vivo, 40 constituents, including 8 prototypes and 32 metabolites were identified in rat plasma and urine samples. In summary, this study showed an insight into the metabolism of ACNE in vivo, which may provide helpful chemical information for better understanding of the toxicological and pharmacological profiles of ACNE. Full article
(This article belongs to the Section Metabolites)
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Open AccessArticle Long-Term In-Service Monitoring and Performance Assessment of the Main Cables of Long-Span Suspension Bridges
Sensors 2017, 17(6), 1414; doi:10.3390/s17061414
Received: 1 May 2017 / Revised: 13 June 2017 / Accepted: 13 June 2017 / Published: 16 June 2017
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Abstract
Despite the recent developments in structural health monitoring, there remain great challenges for accurately, conveniently, and economically assessing the in-service performance of the main cables for long-span suspension bridges. A long-term structural health monitoring technique is developed to measure the tension force with
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Despite the recent developments in structural health monitoring, there remain great challenges for accurately, conveniently, and economically assessing the in-service performance of the main cables for long-span suspension bridges. A long-term structural health monitoring technique is developed to measure the tension force with a conventional sensing technology and further provide the in-service performance assessment strategy of the main cable. The monitoring system adopts conventional vibrating strings transducers to monitor the tension forces of separate cable strands of the main cable in the anchor span. The performance evaluation of the main cable is conducted based on the collected health monitoring data: (1) the measured strand forces are used to derive the overall tension force of a main cable, which is further translated into load bearing capacity assessment using the concept of safety factor; and (2) the proposed technique can also evaluate the uniformity of tension forces from different cable strands. The assessment of uniformity of strand forces of a main cable offers critical information in terms of potential risks of partial damage and performance deterioration of the main cable. The results suggest the proposed low-cost monitoring system is an option to provide approximate estimation of tension forces of main cables for suspension bridges. With the long-term monitoring data, the proposed monitoring-based evaluation methods can further provide critical information to assess the safety and serviceability performance of main cables. Full article
(This article belongs to the Special Issue Sensor Technologies for Health Monitoring of Composite Structures)
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Open AccessArticle Impact of Land Use Intensity on Ecosystem Services: An Example from the Agro-Pastoral Ecotone of Central Inner Mongolia
Sustainability 2017, 9(6), 1030; doi:10.3390/su9061030
Received: 6 April 2017 / Revised: 30 May 2017 / Accepted: 12 June 2017 / Published: 15 June 2017
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Abstract
Land use intensity is an important indicator of human activities, so we quantified the land use intensity and five ecosystem services (soil conservation, water conservation, carbon storage, net primary productivity (NPP), and crop production) in 13 subbasins of the Tabu River Basin in
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Land use intensity is an important indicator of human activities, so we quantified the land use intensity and five ecosystem services (soil conservation, water conservation, carbon storage, net primary productivity (NPP), and crop production) in 13 subbasins of the Tabu River Basin in an agro-pastoral ecotone in central Inner Mongolia. Furthermore, we analyzed the relationships among ecosystem services and the responses of the services to the impact of land use intensity. The primary conclusions were as follows: (1) All five ecosystem services gradually diminished from the upper to the lower reaches of the Tabu River Basin; (2) Water conservation exhibited a trade-off relationship with soil conservation, NPP, and crop production, but it exhibited a synergistic relationship with carbon storage. There were also synergistic relationships between soil conservation, carbon storage, NPP, and crop production; (3) As land use intensity increased, soil conservation, NPP and crop production monotonically increased. In contrast, water conservation exhibited a monotonically decreasing trend, and carbon storage followed a unimodal curve; (4) In this region, suitable ecosystem services were sustained at a land use intensity of approximately 3.95. Full article
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Open AccessArticle Rapid Screening of Graphitic Carbon Nitrides for Photocatalytic Cofactor Regeneration Using a Drop Reactor
Micromachines 2017, 8(6), 175; doi:10.3390/mi8060175
Received: 1 April 2017 / Revised: 24 May 2017 / Accepted: 31 May 2017 / Published: 2 June 2017
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Abstract
Artificial photosynthesis is the imitation of natural photosynthesis, which promises an efficient way to use solar energy to synthesize organic matters, in which the key step is the coenzyme regeneration (NADH/NADPH). To achieve an efficient regeneration rate, various photocatalysts have been developed, such
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Artificial photosynthesis is the imitation of natural photosynthesis, which promises an efficient way to use solar energy to synthesize organic matters, in which the key step is the coenzyme regeneration (NADH/NADPH). To achieve an efficient regeneration rate, various photocatalysts have been developed, such as g-C3N4 and mesoporous carbon nitride (mpg-C3N4). Generally, efficiency determination of different photocatalysts requires laborious experiments, high consumption of reagents, and a considerable amount of time. Here, based on the one-step artificial photosystem I method, we processed the analytical experiment in a very simple PDMS well (20 μL, a drop) to achieve a rapid screening of photocatalysts. For comparison, we used two types of graphitic carbon nitrides, few-layer g-C3N4 and mpg-C3N4. Compared with the slurry systems, firstly, the regeneration rate of mpg-C3N4 drop-reactor system is 4.3 times and 7.1 times those of the few-layer g-C3N4-slurry system and mpg-C3N4-slurry system, respectively. Secondly, this one-drop method reduces the typical verification time from 90 min to 5 min and lowers the liquid volume from 20 mL to 20 μL. Thirdly, this operation is a pump-free and soft lithography technique-free process. The miniaturization of the photocatalytic reaction in the PDMS well improves the regeneration rates, saves samples, and achieves high-throughput screening of multiple photocatalysts. Full article
(This article belongs to the Special Issue Photonic MEMS and Optofluidic Devices)
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Open AccessArticle Performance Analysis of a Four-Switch Three-Phase Grid-Side Converter with Modulation Simplification in a Doubly-Fed Induction Generator-Based Wind Turbine (DFIG-WT) with Different External Disturbances
Energies 2017, 10(5), 706; doi:10.3390/en10050706
Received: 9 March 2017 / Revised: 12 May 2017 / Accepted: 14 May 2017 / Published: 18 May 2017
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Abstract
This paper investigates the performance of a fault-tolerant four-switch three-phase (FSTP) grid-side converter (GSC) in a doubly-fed induction generator-based wind turbine (DFIG-WT). The space vector pulse width modulation (SVPWM) technique is simplified and unified duty ratios are used for controlling the FSTP GSC.
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This paper investigates the performance of a fault-tolerant four-switch three-phase (FSTP) grid-side converter (GSC) in a doubly-fed induction generator-based wind turbine (DFIG-WT). The space vector pulse width modulation (SVPWM) technique is simplified and unified duty ratios are used for controlling the FSTP GSC. Steady DC-bus voltage, sinusoidal three-phase grid currents and unity power factor are obtained. In addition, the balance of capacitor voltages is accomplished based on the analysis of current flows at the midpoint of DC bus in different operational modes. Besides, external disturbances such as fluctuating wind speed and grid voltage sag are considered to test its fault-tolerant ability. Furthermore, the effects of fluctuating wind speed on the performance of DFIG-WT system are explained according to an approximate expression of the turbine torque. The performance of the proposed FSTP GSC is simulated in Matlab/Simulink 2016a based on a detailed 1.5 MW DFIG-WT Simulink model. Experiments are carried out on a 2 kW platform by using a discrete signal processor (DSP) TMS320F28335 controller to validate the reliability of DFIG-WT for the cases with step change of the stator active power and grid voltage sag, respectively. Full article
(This article belongs to the Section Electrical Power and Energy System)
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Open AccessArticle Preparation, Characterization and Properties of Alginate/Poly(γ-glutamic acid) Composite Microparticles
Mar. Drugs 2017, 15(4), 91; doi:10.3390/md15040091
Received: 27 November 2016 / Revised: 12 March 2017 / Accepted: 20 March 2017 / Published: 11 April 2017
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Abstract
Alginate (Alg) is a renewable polymer with excellent hemostatic properties and biocapability and is widely used for hemostatic wound dressing. However, the swelling properties of alginate-based wound dressings need to be promoted to meet the requirements of wider application. Poly(γ-glutamic acid)
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Alginate (Alg) is a renewable polymer with excellent hemostatic properties and biocapability and is widely used for hemostatic wound dressing. However, the swelling properties of alginate-based wound dressings need to be promoted to meet the requirements of wider application. Poly(γ-glutamic acid) (PGA) is a natural polymer with high hydrophility. In the current study, novel Alg/PGA composite microparticles with double network structure were prepared by the emulsification/internal gelation method. It was found from the structure characterization that a double network structure was formed in the composite microparticles due to the ion chelation interaction between Ca2+ and the carboxylate groups of Alg and PGA and the electrostatic interaction between the secondary amine group of PGA and the carboxylate groups of Alg and PGA. The swelling behavior of the composite microparticles was significantly improved due to the high hydrophility of PGA. Influences of the preparing conditions on the swelling behavior of the composites were investigated. The porous microparticles could be formed while compositing of PGA. Thermal stability was studied by thermogravimetric analysis method. Moreover, in vitro cytocompatibility test of microparticles exhibited good biocompatibility with L929 cells. All results indicated that such Alg/PGA composite microparticles are a promising candidate in the field of wound dressing for hemostasis or rapid removal of exudates. Full article
(This article belongs to the collection Marine Polysaccharides)
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Open AccessArticle Grid Mapping for Spatial Pattern Analyses of Recurrent Urban Traffic Congestion Based on Taxi GPS Sensing Data
Sustainability 2017, 9(4), 533; doi:10.3390/su9040533
Received: 6 March 2017 / Revised: 24 March 2017 / Accepted: 28 March 2017 / Published: 31 March 2017
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Abstract
Traffic congestion is one of the most serious problems that impact urban transportation efficiency, especially in big cities. Identifying traffic congestion locations and occurring patterns is a prerequisite for urban transportation managers in order to take proper countermeasures for mitigating traffic congestion. In
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Traffic congestion is one of the most serious problems that impact urban transportation efficiency, especially in big cities. Identifying traffic congestion locations and occurring patterns is a prerequisite for urban transportation managers in order to take proper countermeasures for mitigating traffic congestion. In this study, the historical GPS sensing data of about 12,000 taxi floating cars in Beijing were used for pattern analyses of recurrent traffic congestion based on the grid mapping method. Through the use of ArcGIS software, 2D and 3D maps of the road network congestion were generated for traffic congestion pattern visualization. The study results showed that three types of traffic congestion patterns were identified, namely: point type, stemming from insufficient capacities at the nodes of the road network; line type, caused by high traffic demand or bottleneck issues in the road segments; and region type, resulting from multiple high-demand expressways merging and connecting to each other. The study illustrated that the proposed method would be effective for discovering traffic congestion locations and patterns and helpful for decision makers to take corresponding traffic engineering countermeasures in order to relieve the urban traffic congestion issues. Full article
(This article belongs to the Section Sustainable Engineering and Science)
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Open AccessArticle GC-MS Metabolomic Analysis to Reveal the Metabolites and Biological Pathways Involved in the Developmental Stages and Tissue Response of Panax ginseng
Molecules 2017, 22(3), 496; doi:10.3390/molecules22030496
Received: 11 January 2017 / Revised: 14 March 2017 / Accepted: 16 March 2017 / Published: 21 March 2017
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Abstract
Ginsenosides, the major compounds present in ginseng, are known to have numerous physiological and pharmacological effects. The physiological processes, enzymes and genes involved in ginsenoside synthesis in P. ginseng have been well characterized. However, relatively little information is known about the dynamic metabolic
[...] Read more.
Ginsenosides, the major compounds present in ginseng, are known to have numerous physiological and pharmacological effects. The physiological processes, enzymes and genes involved in ginsenoside synthesis in P. ginseng have been well characterized. However, relatively little information is known about the dynamic metabolic changes that occur during ginsenoside accumulation in ginseng. To explore this topic, we isolated metabolites from different tissues at different growth stages, and identified and characterized them by using gas chromatography coupled with mass spectrometry (GC-MS). The results showed that a total of 30, 16, 20, 36 and 31 metabolites were identified and involved in different developmental stages in leaf, stem, petiole, lateral root and main root, respectively. To investigate the contribution of tissue to the biosynthesis of ginsenosides, we examined the metabolic changes of leaf, stem, petiole, lateral root and main root during five development stages: 1-, 2-, 3-, 4- and 5-years. The score plots of partial least squares-discriminate analysis (PLS-DA) showed clear discrimination between growth stages and tissue samples. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis in the same tissue at different growth stages indicated profound biochemical changes in several pathways, including carbohydrate metabolism and pentose phosphate metabolism, in addition, the tissues displayed significant variations in amino acid metabolism, sugar metabolism and energy metabolism. These results should facilitate further dissection of the metabolic flux regulation of ginsenoside accumulation in different developmental stages or different tissues of ginseng. Full article
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Open AccessArticle Economic Burden for Lung Cancer Survivors in Urban China
Int. J. Environ. Res. Public Health 2017, 14(3), 308; doi:10.3390/ijerph14030308
Received: 22 November 2016 / Revised: 27 February 2017 / Accepted: 27 February 2017 / Published: 15 March 2017
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Abstract
Background: With the rapid increase in the incidence and mortality of lung cancer, a growing number of lung cancer patients and their families are faced with a tremendous economic burden because of the high cost of treatment in China. This study was
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Background: With the rapid increase in the incidence and mortality of lung cancer, a growing number of lung cancer patients and their families are faced with a tremendous economic burden because of the high cost of treatment in China. This study was conducted to estimate the economic burden and patient responsibility of lung cancer patients and the impact of this burden on family income. Methods: This study uses data from a retrospective questionnaire survey conducted in 10 communities in urban China and includes 195 surviving lung cancer patients diagnosed over the previous five years. The calculation of direct economic burden included both direct medical and direct nonmedical costs. Indirect costs were calculated using the human capital approach, which measures the productivity lost for both patients and family caregivers. The price index was applied for the cost calculation. Results: The average economic burden from lung cancer was $43,336 per patient, of which the direct cost per capita was $42,540 (98.16%) and the indirect cost per capita was $795 (1.84%). Of the total direct medical costs, 35.66% was paid by the insurer and 9.84% was not covered by insurance. The economic burden for diagnosed lung cancer patients in the first year following diagnosis was $30,277 per capita, which accounted for 171% of the household annual income, a percentage that fell to 107% after subtracting the compensation from medical insurance. Conclusions: The economic burden for lung cancer patients is substantial in the urban areas of China, and an effective control strategy to lower the cost is urgently needed. Full article
(This article belongs to the Section Health Services and Health Economics Research)
Open AccessArticle Systematic Identification and Assessment of Therapeutic Targets for Breast Cancer Based on Genome-Wide RNA Interference Transcriptomes
Genes 2017, 8(3), 86; doi:10.3390/genes8030086
Received: 1 December 2016 / Revised: 24 January 2017 / Accepted: 13 February 2017 / Published: 24 February 2017
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Abstract
With accumulating public omics data, great efforts have been made to characterize the genetic heterogeneity of breast cancer. However, identifying novel targets and selecting the best from the sizeable lists of candidate targets is still a key challenge for targeted therapy, largely owing
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With accumulating public omics data, great efforts have been made to characterize the genetic heterogeneity of breast cancer. However, identifying novel targets and selecting the best from the sizeable lists of candidate targets is still a key challenge for targeted therapy, largely owing to the lack of economical, efficient and systematic discovery and assessment to prioritize potential therapeutic targets. Here, we describe an approach that combines the computational evaluation and objective, multifaceted assessment to systematically identify and prioritize targets for biological validation and therapeutic exploration. We first establish the reference gene expression profiles from breast cancer cell line MCF7 upon genome-wide RNA interference (RNAi) of a total of 3689 genes, and the breast cancer query signatures using RNA-seq data generated from tissue samples of clinical breast cancer patients in the Cancer Genome Atlas (TCGA). Based on gene set enrichment analysis, we identified a set of 510 genes that when knocked down could significantly reverse the transcriptome of breast cancer state. We then perform multifaceted assessment to analyze the gene set to prioritize potential targets for gene therapy. We also propose drug repurposing opportunities and identify potentially druggable proteins that have been poorly explored with regard to the discovery of small-molecule modulators. Finally, we obtained a small list of candidate therapeutic targets for four major breast cancer subtypes, i.e., luminal A, luminal B, HER2+ and triple negative breast cancer. This RNAi transcriptome-based approach can be a helpful paradigm for relevant researches to identify and prioritize candidate targets for experimental validation. Full article
(This article belongs to the Special Issue RNA Interference 2016)
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Open AccessArticle Maximum Safety Regenerative Power Tracking for DC Traction Power Systems
Energies 2017, 10(2), 244; doi:10.3390/en10020244
Received: 25 December 2016 / Revised: 11 February 2017 / Accepted: 12 February 2017 / Published: 17 February 2017
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Abstract
Direct current (DC) traction power systems are widely used in metro transport systems, with running rails usually being used as return conductors. When traction current flows through the running rails, a potential voltage known as “rail potential” is generated between the rails and
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Direct current (DC) traction power systems are widely used in metro transport systems, with running rails usually being used as return conductors. When traction current flows through the running rails, a potential voltage known as “rail potential” is generated between the rails and ground. Currently, abnormal rises of rail potential exist in many railway lines during the operation of railway systems. Excessively high rail potentials pose a threat to human life and to devices connected to the rails. In this paper, the effect of regenerative power distribution on rail potential is analyzed. Maximum safety regenerative power tracking is proposed for the control of maximum absolute rail potential and energy consumption during the operation of DC traction power systems. The dwell time of multiple trains at each station and the trigger voltage of the regenerative energy absorbing device (READ) are optimized based on an improved particle swarm optimization (PSO) algorithm to manage the distribution of regenerative power. In this way, the maximum absolute rail potential and energy consumption of DC traction power systems can be reduced. The operation data of Guangzhou Metro Line 2 are used in the simulations, and the results show that the scheme can reduce the maximum absolute rail potential and energy consumption effectively and guarantee the safety in energy saving of DC traction power systems. Full article
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Open AccessArticle Ustiloxin G, a New Cyclopeptide Mycotoxin from Rice False Smut Balls
Toxins 2017, 9(2), 54; doi:10.3390/toxins9020054
Received: 20 December 2016 / Accepted: 6 February 2017 / Published: 10 February 2017
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Abstract
Ustiloxins were cyclopeptide mycotoxins from rice false smut balls (FSBs) that formed in rice spikelets infected by the fungal pathogen Ustilaginoidea virens. To investigate the chemical diversity of these metabolites and their bioactivities, one new cyclopeptide, ustiloxin G (1), together
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Ustiloxins were cyclopeptide mycotoxins from rice false smut balls (FSBs) that formed in rice spikelets infected by the fungal pathogen Ustilaginoidea virens. To investigate the chemical diversity of these metabolites and their bioactivities, one new cyclopeptide, ustiloxin G (1), together with four known congeners—ustiloxins A (2), B (3), D (4), and F (5)—were isolated from water extract of rice FSBs. Their structures were elucidated by analyses of their physical and spectroscopic data, including ultraviolet spectrometry (UV), infrared spectroscopy (IR), 1D and 2D nuclear magnetic resonance (NMR), and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS). All the compounds were evaluated for their cytotoxic as well as radicle and germ elongation inhibitory activities. Ustiloxin B (3) showed the best activity against the cell line BGC-823 with an IC50 value of 1.03 µM, while ustiloxin G (1) showed moderate activity against the cell lines A549 and A375 with IC50 values of 36.5 µM and 22.5 µM, respectively. Ustiloxins A (2), B (3), and G (1) showed strong inhibition of radicle and germ elongation of rice seeds. When their concentrations were at 200 µg/mL, the inhibitory ratios of radicle and germ elongation were more than 90% and 50%, respectively, the same effect as that of positive control (glyphosate). They also induced abnormal swelling of the roots and germs of rice seedlings. Full article
(This article belongs to the Section Mycotoxins)
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Open AccessArticle Microstructure Characterization and Wear-Resistant Properties Evaluation of an Intermetallic Composite in Ni–Mo–Si System
Materials 2017, 10(2), 130; doi:10.3390/ma10020130
Received: 24 December 2016 / Revised: 22 January 2017 / Accepted: 26 January 2017 / Published: 4 February 2017
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Abstract
Intermetallic compounds have been studied for their potential application as structural wear materials or coatings on engineering steels. In the present work, a newly designed intermetallic composite in a Ni–Mo–Si system was fabricated by arc-melting process with commercially pure metal powders as starting
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Intermetallic compounds have been studied for their potential application as structural wear materials or coatings on engineering steels. In the present work, a newly designed intermetallic composite in a Ni–Mo–Si system was fabricated by arc-melting process with commercially pure metal powders as starting materials. The chemical composition of this intermetallic composite is 45Ni–40Mo–15Si (at %), selected according to the ternary alloy diagram. The microstructure was characterized using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), and the wear-resistant properties at room temperature were evaluated under different wear test conditions. Microstructure characterization showed that the composite has a dense and uniform microstructure. XRD results showed that the intermetallic composite is constituted by a binary intermetallic compound NiMo and a ternary Mo2Ni3Si metal silicide phase. Wear test results indicated that the intermetallic composite has an excellent wear-resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases NiMo and Mo2Ni3Si. Full article
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Open AccessArticle Detoxification of Aflatoxin B1 by Zygosaccharomyces rouxii with Solid State Fermentation in Peanut Meal
Toxins 2017, 9(1), 42; doi:10.3390/toxins9010042
Received: 5 December 2016 / Revised: 17 January 2017 / Accepted: 17 January 2017 / Published: 20 January 2017
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Abstract
Aflatoxins are highly carcinogenic, teratogenetic, and morbigenous secondary metabolites of Aspergillus flavus and A. parasiticus that can contaminate multiple staple foods, such as peanut, maize, and tree nuts. In this study, Zygosaccharomyces rouxii was screened out and identified from fermented soy paste—one kind
[...] Read more.
Aflatoxins are highly carcinogenic, teratogenetic, and morbigenous secondary metabolites of Aspergillus flavus and A. parasiticus that can contaminate multiple staple foods, such as peanut, maize, and tree nuts. In this study, Zygosaccharomyces rouxii was screened out and identified from fermented soy paste—one kind of traditional Chinese food—to detoxify aflatoxin B1 (AFB1) by aerobic solid state fermentation in peanut meal. The optimal degradation condition was chosen from single factor experiment, and the most effective detoxification rate was about 97%. As for liquid fermentation, we tested the binding ability of Z. rouxii, and the highest binding rate reached was 74.3% (nonviable cells of Z. rouxii) in phosphate-buffered saline (PBS). Moreover, the biotransformation of AFB1 through fermentation of Z. rouxii in peanut meal was further verified by liquid chromatography/mass spectrometry (LC/MS). According to TIC scan, after fermentation by Z. rouxii, the AFB1 in peanut meal was prominently degraded to the lowering peaks of AFB1. Additionally, m/s statistics demonstrated that AFB1 may be degraded to some new products whose structural properties may be different from AFB1, or the degradation products may be dissolved in the aqueous phase rather than the organic phase. As far as we know, this is the first report indicating that the safe strain of Z. rouxii has the ability to detoxify AFB1. Full article
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Open AccessArticle A Survey of Aflatoxin-Producing Aspergillus sp. from Peanut Field Soils in Four Agroecological Zones of China
Toxins 2017, 9(1), 40; doi:10.3390/toxins9010040
Received: 25 October 2016 / Revised: 5 January 2017 / Accepted: 6 January 2017 / Published: 20 January 2017
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Abstract
Peanut pods are easily infected by aflatoxin-producing Aspergillus sp.ecies from field soil. To assess the aflatoxin-producing Aspergillus sp. in different peanut field soils, 344 aflatoxin-producing Aspergillus strains were isolated from 600 soil samples of four agroecological zones in China (the Southeast coastal zone
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Peanut pods are easily infected by aflatoxin-producing Aspergillus sp.ecies from field soil. To assess the aflatoxin-producing Aspergillus sp. in different peanut field soils, 344 aflatoxin-producing Aspergillus strains were isolated from 600 soil samples of four agroecological zones in China (the Southeast coastal zone (SEC), the Yangtze River zone (YZR), the Yellow River zone (YR) and the Northeast zone (NE)). Nearly 94.2% (324/344) of strains were A. flavus and 5.8% (20/344) of strains were A. parasiticus. YZR had the highest population density of Aspergillus sp. and positive rate of aflatoxin production in isolated strains (1039.3 cfu·g−1, 80.7%), the second was SEC (191.5 cfu·g−1, 48.7%), the third was YR (26.5 cfu·g−1, 22.7%), and the last was NE (2.4 cfu·g−1, 6.6%). The highest risk of AFB1 contamination on peanut was in YZR which had the largest number of AFB1 producing isolates in 1g soil, followed by SEC and YR, and the lowest was NE. The potential risk of AFB1 contamination in peanuts can increase with increasing population density and a positive rate of aflatoxin-producing Aspergillus sp. in field soils, suggesting that reducing aflatoxigenic Aspergillus sp. in field soils could prevent AFB1 contamination in peanuts. Full article
(This article belongs to the Special Issue Exposure and Risk Assessment for Mycotoxins)
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Open AccessArticle Coordinated Control of Superconducting Fault Current Limiter and Superconducting Magnetic Energy Storage for Transient Performance Enhancement of Grid-Connected Photovoltaic Generation System
Energies 2017, 10(1), 56; doi:10.3390/en10010056
Received: 23 September 2016 / Revised: 13 December 2016 / Accepted: 26 December 2016 / Published: 5 January 2017
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Abstract
In regard to the rapid development of renewable energy sources, more and more photovoltaic (PV) generation systems have been connected to main power networks, and it is critical to enhance their transient performance under short-circuit faults conditions. This paper proposes and studies the
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In regard to the rapid development of renewable energy sources, more and more photovoltaic (PV) generation systems have been connected to main power networks, and it is critical to enhance their transient performance under short-circuit faults conditions. This paper proposes and studies the coordinated control of a flux-coupling-type superconducting fault current limiter (SFCL) and a superconducting magnetic energy storage (SMES), to improve the fault ride through (FRT) capability and smooth the power fluctuation of a grid-connected PV generation system. Theoretical analyses of the device structure, operating principle and control strategy are conducted, and a detailed simulation model of 100 kW class PV generation system is built in MATLAB/SIMULINK. During the simulations of the symmetrical and asymmetrical faults, the maximum power point tracking (MPPT) control is disabled, and four different cases including without auxiliary, with SFCL, with SMES, and with SFCL-SMES, are compared. From the demonstrated results, the combination of without MPPT and with SFCL-SMES can more efficiently improve the point of common coupling (PCC) voltage sag, inhibit the DC-link overvoltage and alleviate the power fluctuation. Finally, a preliminary parameter optimization method is suggested for the SFCL and the SMES, and it is helpful to promote their future application in the real PV projects. Full article
(This article belongs to the Special Issue Grid-Connected Photovoltaic Systems)
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Open AccessArticle The Role of Deoxycytidine Kinase (dCK) in Radiation-Induced Cell Death
Int. J. Mol. Sci. 2016, 17(11), 1939; doi:10.3390/ijms17111939
Received: 22 August 2016 / Revised: 12 October 2016 / Accepted: 14 November 2016 / Published: 21 November 2016
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Abstract
Deoxycytidine kinase (dCK) is a key enzyme in deoxyribonucleoside salvage and the anti-tumor activity for many nucleoside analogs. dCK is activated in response to ionizing radiation (IR)-induced DNA damage and it is phosphorylated on Serine 74 by the Ataxia-Telangiectasia Mutated (ATM) kinase in
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Deoxycytidine kinase (dCK) is a key enzyme in deoxyribonucleoside salvage and the anti-tumor activity for many nucleoside analogs. dCK is activated in response to ionizing radiation (IR)-induced DNA damage and it is phosphorylated on Serine 74 by the Ataxia-Telangiectasia Mutated (ATM) kinase in order to activate the cell cycle G2/M checkpoint. However, whether dCK plays a role in radiation-induced cell death is less clear. In this study, we genetically modified dCK expression by knocking down or expressing a WT (wild-type), S74A (abrogates phosphorylation) and S74E (mimics phosphorylation) of dCK. We found that dCK could decrease IR-induced total cell death and apoptosis. Moreover, dCK increased IR-induced autophagy and dCK-S74 is required for it. Western blotting showed that the ratio of phospho-Akt/Akt, phospho-mTOR/mTOR, phospho-P70S6K/P70S6K significantly decreased in dCK-WT and dCK-S74E cells than that in dCK-S74A cells following IR treatment. Reciprocal experiment by co-immunoprecipitation showed that mTOR can interact with wild-type dCK. IR increased polyploidy and decreased G2/M arrest in dCK knock-down cells as compared with control cells. Taken together, phosphorylated and activated dCK can inhibit IR-induced cell death including apoptosis and mitotic catastrophe, and promote IR-induced autophagy through PI3K/Akt/mTOR pathway. Full article
(This article belongs to the collection Programmed Cell Death and Apoptosis)
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Open AccessCorrection Correction: Liu, Y. et al. Time-Dependent Afterslip of the 2009 Mw 6.3 Dachaidan Earthquake (China) and Viscosity beneath the Qaidam Basin Inferred from Postseismic Deformation Observations. Remote Sens. 2016, 8, 649
Remote Sens. 2016, 8(9), 784; doi:10.3390/rs8090784
Received: 6 September 2016 / Accepted: 16 September 2016 / Published: 21 September 2016
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Abstract After publication of the research paper [1] an error was recognized.[...] Full article
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Open AccessArticle New Supercapacitors Based on the Synergetic Redox Effect between Electrode and Electrolyte
Materials 2016, 9(9), 734; doi:10.3390/ma9090734
Received: 27 July 2016 / Revised: 23 August 2016 / Accepted: 23 August 2016 / Published: 29 August 2016
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Abstract
Redox electrolytes can provide significant enhancement of capacitance for supercapacitors. However, more important promotion comes from the synergetic effect and matching between the electrode and electrolyte. Herein, we report a novel electrochemical system consisted of a polyanilline/carbon nanotube composite redox electrode and a
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Redox electrolytes can provide significant enhancement of capacitance for supercapacitors. However, more important promotion comes from the synergetic effect and matching between the electrode and electrolyte. Herein, we report a novel electrochemical system consisted of a polyanilline/carbon nanotube composite redox electrode and a hydroquinone (HQ) redox electrolyte, which exhibits a specific capacitance of 7926 F/g in a three-electrode system when the concentration of HQ in H2SO4 aqueous electrolyte is 2 mol/L, and the maximum energy density of 114 Wh/kg in two-electrode symmetric configuration. Moreover, the specific capacitance retention of 96% after 1000 galvanostatic charge/discharge cycles proves an excellent cyclic stability. These ultrahigh performances of the supercapacitor are attributed to the synergistic effect both in redox polyanilline-based electrolyte and the redox hydroquinone electrode. Full article
(This article belongs to the Section Materials for Energy Applications)
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Open AccessArticle Time-Dependent Afterslip of the 2009 Mw 6.3 Dachaidan Earthquake (China) and Viscosity beneath the Qaidam Basin Inferred from Postseismic Deformation Observations
Remote Sens. 2016, 8(8), 649; doi:10.3390/rs8080649
Received: 30 June 2016 / Revised: 31 July 2016 / Accepted: 3 August 2016 / Published: 10 August 2016
Cited by 2 | Viewed by 653 | PDF Full-text (6574 KB) | HTML Full-text | XML Full-text | Correction
Abstract
The 28 August 2009 Mw 6.3 Dachaidan (DCD) earthquake occurred at the Qaidam Basin’s northern side. To explain its postseismic deformation time series, the method of modeling them with a combination model of afterslip and viscoelastic relaxation is improved to simultaneously assess the
[...] Read more.
The 28 August 2009 Mw 6.3 Dachaidan (DCD) earthquake occurred at the Qaidam Basin’s northern side. To explain its postseismic deformation time series, the method of modeling them with a combination model of afterslip and viscoelastic relaxation is improved to simultaneously assess the time-dependent afterslip and the viscosity. The coseismic slip model in the layered model is first inverted, showing a slip pattern close to that in the elastic half-space. The postseismic deformation time series can be explained by the combination model, with a total root mean square (RMS) misfit of 0.37 cm. The preferred time-dependent afterslip mainly occurs at a depth from the surface to about 9.1 km underground and increases with time, indicating that afterslip will continue after 28 July 2010. By 334 days after the main shock, the moment released by the afterslip is 0.91 × 1018 N∙m (Mw 5.94), approximately 24.3% of that released by the coseismic slip. The preferred lower bound of the viscosity beneath the Qaidam Basin’s northern side is 1 × 1019 Pa·s, close to that beneath its southern side. This result also indicates that the viscosity structure beneath the Tibet Plateau may vary laterally. Full article
(This article belongs to the Special Issue Earth Observations for Geohazards) Printed Edition available
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Open AccessArticle Incentives for Delay-Constrained Data Query and Feedback in Mobile Opportunistic Crowdsensing
Sensors 2016, 16(7), 1138; doi:10.3390/s16071138
Received: 19 April 2016 / Revised: 26 June 2016 / Accepted: 12 July 2016 / Published: 21 July 2016
Cited by 4 | Viewed by 668 | PDF Full-text (419 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, we propose effective data collection schemes that stimulate cooperation between selfish users in mobile opportunistic crowdsensing. A query issuer generates a query and requests replies within a given delay budget. When a data provider receives the query for the first
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In this paper, we propose effective data collection schemes that stimulate cooperation between selfish users in mobile opportunistic crowdsensing. A query issuer generates a query and requests replies within a given delay budget. When a data provider receives the query for the first time from an intermediate user, the former replies to it and authorizes the latter as the owner of the reply. Different data providers can reply to the same query. When a user that owns a reply meets the query issuer that generates the query, it requests the query issuer to pay credits. The query issuer pays credits and provides feedback to the data provider, which gives the reply. When a user that carries a feedback meets the data provider, the data provider pays credits to the user in order to adjust its claimed expertise. Queries, replies and feedbacks can be traded between mobile users. We propose an effective mechanism to define rewards for queries, replies and feedbacks. We formulate the bargain process as a two-person cooperative game, whose solution is found by using the Nash theorem. To improve the credit circulation, we design an online auction process, in which the wealthy user can buy replies and feedbacks from the starving one using credits. We have carried out extensive simulations based on real-world traces to evaluate the proposed schemes. Full article
Open AccessReview Strategies to Optimize Adult Stem Cell Therapy for Tissue Regeneration
Int. J. Mol. Sci. 2016, 17(6), 982; doi:10.3390/ijms17060982
Received: 7 April 2016 / Revised: 6 May 2016 / Accepted: 10 May 2016 / Published: 21 June 2016
Cited by 11 | Viewed by 1224 | PDF Full-text (260 KB) | HTML Full-text | XML Full-text
Abstract
Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells) commit to becoming
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Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells) commit to becoming the functional cells from their tissue of origin. These cells are the most commonly used in cell-based therapy since they do not confer risk of teratomas, do not require fetal stem cell maneuvers and thus are free of ethical concerns, and they confer low immunogenicity (even if allogenous). The goal of this review is to summarize the current state of the art and advances in using stem cell therapy for tissue repair in solid organs. Here we address key factors in cell preparation, such as the source of adult stem cells, optimal cell types for implantation (universal mesenchymal stem cells vs. tissue-specific stem cells, or induced vs. non-induced stem cells), early or late passages of stem cells, stem cells with endogenous or exogenous growth factors, preconditioning of stem cells (hypoxia, growth factors, or conditioned medium), using various controlled release systems to deliver growth factors with hydrogels or microspheres to provide apposite interactions of stem cells and their niche. We also review several approaches of cell delivery that affect the outcomes of cell therapy, including the appropriate routes of cell administration (systemic, intravenous, or intraperitoneal vs. local administration), timing for cell therapy (immediate vs. a few days after injury), single injection of a large number of cells vs. multiple smaller injections, a single site for injection vs. multiple sites and use of rodents vs. larger animal models. Future directions of stem cell-based therapies are also discussed to guide potential clinical applications. Full article
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Open AccessArticle An Approach to Characterizing the Complicated Sequential Metabolism of Salidroside in Rats
Molecules 2016, 21(6), 706; doi:10.3390/molecules21060706
Received: 11 April 2016 / Revised: 25 May 2016 / Accepted: 25 May 2016 / Published: 30 May 2016
Cited by 3 | Viewed by 653 | PDF Full-text (825 KB) | HTML Full-text | XML Full-text
Abstract
Metabolic study of bioactive compounds that undergo a dynamic and sequential process of metabolism is still a great challenge. Salidroside, one of the most active ingredients of Rhodiola crenulata, can be metabolized in different sites before being absorbed into the systemic blood
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Metabolic study of bioactive compounds that undergo a dynamic and sequential process of metabolism is still a great challenge. Salidroside, one of the most active ingredients of Rhodiola crenulata, can be metabolized in different sites before being absorbed into the systemic blood stream. This study proposed an approach for describing the sequential biotransformation process of salidroside based on comparative analysis. In vitro incubation, in situ closed-loop and in vivo blood sampling were used to determine the relative contribution of each site to the total metabolism of salidroside. The results showed that salidroside was stable in digestive juice, and it was metabolized primarily by the liver and the intestinal flora and to a lesser extent by the gut wall. The sequential metabolism method described in this study could be a general approach to characterizing the metabolic routes in the digestive system for natural products. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Investigation and Evaluation of Children’s Blood Lead Levels around a Lead Battery Factory and Influencing Factors
Int. J. Environ. Res. Public Health 2016, 13(6), 541; doi:10.3390/ijerph13060541
Received: 17 February 2016 / Revised: 20 May 2016 / Accepted: 24 May 2016 / Published: 28 May 2016
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Abstract
Lead pollution incidents have occurred frequently in mainland China, which has caused many lead poisoning incidents. This paper took a battery recycling factory as the subject, and focused on measuring the blood lead levels of environmental samples and all the children living around
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Lead pollution incidents have occurred frequently in mainland China, which has caused many lead poisoning incidents. This paper took a battery recycling factory as the subject, and focused on measuring the blood lead levels of environmental samples and all the children living around the factory, and analyzed the relationship between them. We collected blood samples from the surrounding residential area, as well as soil, water, vegetables. The atomic absorption method was applied to measure the lead content in these samples. The basic information of the generation procedure, operation type, habit and personal protect equipment was collected by an occupational hygiene investigation. Blood lead levels in 43.12% of the subjects exceeded 100 μg/L. The 50th and the 95th percentiles were 89 μg/L and 232 μg/L for blood lead levels in children, respectively, and the geometric mean was 94 μg/L. Children were stratified into groups by age, gender, parents’ occupation, distance and direction from the recycling plant. The difference of blood lead levels between groups was significant (p < 0.05). Four risk factors for elevated blood lead levels were found by logistic regression analysis, including younger age, male, shorter distance from the recycling plant, and parents with at least one working in the recycling plant. The rate of excess lead concentration in water was 6.25%, 6.06% in soil and 44.44% in leaf vegetables, which were all higher than the Chinese environment standards. The shorter the distance to the factory, the higher the value of BLL and lead levels in vegetable and environment samples. The lead level in the environmental samples was higher downwind of the recycling plant. Full article
Open AccessReview Ochratoxin A Producing Fungi, Biosynthetic Pathway and Regulatory Mechanisms
Toxins 2016, 8(3), 83; doi:10.3390/toxins8030083
Received: 1 February 2016 / Revised: 28 February 2016 / Accepted: 14 March 2016 / Published: 21 March 2016
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Abstract
Ochratoxin A (OTA), mainly produced by Aspergillus and Penicillum species, is one of the most important mycotoxin contaminants in agricultural products. It is detrimental to human health because of its nephrotoxicity, hepatotoxicity, carcinogenicity, teratogenicity, and immunosuppression. OTA structurally consists of adihydrocoumarin moiety linked
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Ochratoxin A (OTA), mainly produced by Aspergillus and Penicillum species, is one of the most important mycotoxin contaminants in agricultural products. It is detrimental to human health because of its nephrotoxicity, hepatotoxicity, carcinogenicity, teratogenicity, and immunosuppression. OTA structurally consists of adihydrocoumarin moiety linked with l-phenylalanine via an amide bond. OTA biosynthesis has been putatively hypothesized, although several contradictions exist on some processes of the biosynthetic pathway. We discuss recent information on molecular studies of OTA biosynthesis despite insufficient genetic background in detail. Accordingly, genetic regulation has also been explored with regard to the interaction between the regulators and the environmental factors. In this review, we focus on three aspects of OTA: OTA-producing strains, OTA biosynthetic pathway and the regulation mechanisms of OTA production. This can pave the way to assist in protecting food and feed from OTA contamination by understanding OTA biosynthetic pathway and regulatory mechanisms. Full article
(This article belongs to the collection Ochratoxins-Collection)
Open AccessArticle Heterogeneous Fault Mechanisms of the 6 October 2008 MW 6.3 Dangxiong (Tibet) Earthquake Using Interferometric Synthetic Aperture Radar Observations
Remote Sens. 2016, 8(3), 228; doi:10.3390/rs8030228
Received: 23 October 2015 / Revised: 25 February 2016 / Accepted: 1 March 2016 / Published: 12 March 2016
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Abstract
Most current crustal deformation models do not account for topographic effects, crustal lateral variations, and complex fault geometries. To overcome these limitations, we apply finite element models constrained by interferometric Synthetic Aperture Radar (InSAR) images of co-seismic displacements to the 2008 Mw
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Most current crustal deformation models do not account for topographic effects, crustal lateral variations, and complex fault geometries. To overcome these limitations, we apply finite element models constrained by interferometric Synthetic Aperture Radar (InSAR) images of co-seismic displacements to the 2008 Mw 6.3 Dangxiong earthquake that occurred in Yadong–Gulu rift, southern Tibet. For mountainous plateau environments, InSAR observations are advantageous for studying crustal deformation and crustal medium structure. We evaluate the effect of topography and variations in Poisson’s ratio and elastic moduli on estimation of coseismic deformation from InSAR observations. The results show that coseismic surface displacements are more sensitive to variations in Young’s modulus than to variations in topography and Poisson’s ratio. Therefore, with constant Poisson’s ratio and density, we change the Young’s modulus on each side of the fault to obtain the model that best fits the observations. This is attained when the Young’s moduli in the eastern and western sides of the fault were 2.6 × 1010 Pa and 7.8 × 1010 Pa, respectively. The result is consistent with previous field surveys that the medium on either side of the fault is different. Full article
(This article belongs to the Special Issue Remote Sensing in Tibet and Siberia)
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Open AccessArticle Interseismic Deformation of the Altyn Tagh Fault Determined by Interferometric Synthetic Aperture Radar (InSAR) Measurements
Remote Sens. 2016, 8(3), 233; doi:10.3390/rs8030233
Received: 27 November 2015 / Revised: 29 February 2016 / Accepted: 4 March 2016 / Published: 11 March 2016
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Abstract
The Altyn Tagh Fault (ATF) is one of the major left-lateral strike-slip faults in the northeastern area of the Tibetan Plateau. In this study, the interseismic deformation across the ATF at 85°E was measured using 216 interferograms from 33 ENVISAT advanced synthetic aperture
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The Altyn Tagh Fault (ATF) is one of the major left-lateral strike-slip faults in the northeastern area of the Tibetan Plateau. In this study, the interseismic deformation across the ATF at 85°E was measured using 216 interferograms from 33 ENVISAT advanced synthetic aperture radar images on a descending track acquired from 2003 to 2010, and 66 interferograms from 15 advanced synthetic aperture radar images on an ascending track acquired from 2005 to 2010. To retrieve the pattern of interseismic strain accumulation, a global atmospheric model (ERA-Interim) provided by the European Center for Medium Range Weather Forecast and a global network orbital correction approach were applied to remove atmospheric effects and the long-wavelength orbital errors in the interferograms. Then, the interferometric synthetic aperture radar (InSAR) time series with atmospheric estimation model was used to obtain a deformation rate map for the ATF. Based on the InSAR velocity map, the regional strain rates field was calculated for the first time using the multi-scale wavelet method. The strain accumulation is strongly focused on the ATF with the maximum strain rate of 12.4 × 10−8/year. We also show that high-resolution 2-D strain rates field can be calculated from InSAR alone, even without GPS data. Using a simple half-space elastic screw dislocation model, the slip-rate and locking depth were estimated with both ascending and descending surface velocity measurements. The joint inversion results are consistent with a left-lateral slip rate of 8.0 ± 0.7 mm/year on the ATF and a locking depth of 14.5 ± 3 km, which is in agreement with previous results from GPS surveys and ERS InSAR results. Our results support the dynamic models of Asian deformation requiring low fault slip rate. Full article
(This article belongs to the Special Issue Earth Observations for Geohazards) Printed Edition available
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Open AccessReview Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review
Catalysts 2016, 6(2), 32; doi:10.3390/catal6020032
Received: 14 December 2015 / Revised: 19 January 2016 / Accepted: 21 January 2016 / Published: 22 February 2016
Cited by 11 | Viewed by 1092 | PDF Full-text (249 KB) | HTML Full-text | XML Full-text
Abstract
Enormous interest in biocatalysis in non-aqueous phase has recently been triggered due to the merits of good enantioselectivity, reverse thermodynamic equilibrium, and no water-dependent side reactions. It has been demonstrated that enzyme has high activity and stability in non-aqueous media, and the variation
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Enormous interest in biocatalysis in non-aqueous phase has recently been triggered due to the merits of good enantioselectivity, reverse thermodynamic equilibrium, and no water-dependent side reactions. It has been demonstrated that enzyme has high activity and stability in non-aqueous media, and the variation of enzyme activity is attributed to its conformational modifications. This review comprehensively addresses the stability and activity of the intact enzymes in various non-aqueous systems, such as organic solvents, ionic liquids, sub-/super-critical fluids and their combined mixtures. It has been revealed that critical factors such as Log P, functional groups and the molecular structures of the solvents define the microenvironment surrounding the enzyme molecule and affect enzyme tertiary and secondary structure, influencing enzyme catalytic properties. Therefore, it is of high importance for biocatalysis in non-aqueous media to elucidate the links between the microenvironment surrounding enzyme surface and its stability and activity. In fact, a better understanding of the correlation between different non-aqueous environments and enzyme structure, stability and activity can contribute to identifying the most suitable reaction medium for a given biotransformation. Full article
(This article belongs to the Special Issue Enzyme Catalysis)
Open AccessArticle Post-Seismic Deformation from the 2009 Mw 6.3 Dachaidan Earthquake in the Northern Qaidam Basin Detected by Small Baseline Subset InSAR Technique
Sensors 2016, 16(2), 206; doi:10.3390/s16020206
Received: 1 November 2015 / Revised: 28 January 2016 / Accepted: 3 February 2016 / Published: 5 February 2016
Cited by 1 | Viewed by 1007 | PDF Full-text (2675 KB) | HTML Full-text | XML Full-text
Abstract
On 28 August 2009, one thrust-faulting Mw 6.3 earthquake struck the northern Qaidam basin, China. Due to the lack of ground observations in this remote region, this study presents high-precision and high spatio-temporal resolution post-seismic deformation series with a small baseline subset InSAR
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On 28 August 2009, one thrust-faulting Mw 6.3 earthquake struck the northern Qaidam basin, China. Due to the lack of ground observations in this remote region, this study presents high-precision and high spatio-temporal resolution post-seismic deformation series with a small baseline subset InSAR technique. At the temporal scale, this changes from fast to slow with time, with a maximum uplift up to 7.4 cm along the line of sight 334 days after the event. At the spatial scale, this is more obvious at the hanging wall than that at the footwall, and decreases from the middle to both sides at the hanging wall. We then propose a method to calculate the correlation coefficient between co-seismic and post-seismic deformation by normalizing them. The correlation coefficient is found to be 0.73, indicating a similar subsurface process occurring during both phases. The results indicate that afterslip may dominate the post-seismic deformation during 19–334 days after the event, which mainly occurs with the fault geometry and depth similar to those of the c-seismic rupturing, and partly extends to the shallower and deeper depths. Full article
(This article belongs to the Section Remote Sensors)
Open AccessArticle RpoN Regulates Virulence Factors of Pseudomonas aeruginosa via Modulating the PqsR Quorum Sensing Regulator
Int. J. Mol. Sci. 2015, 16(12), 28311-28319; doi:10.3390/ijms161226103
Received: 13 August 2015 / Revised: 9 November 2015 / Accepted: 23 November 2015 / Published: 30 November 2015
Cited by 2 | Viewed by 1357 | PDF Full-text (3308 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The alternative sigma factor RpoN regulates many cell functions, such as motility, quorum sensing, and virulence in the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa often evolves rpoN-negative variants during the chronic infection in cystic fibrosis patients. It is
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The alternative sigma factor RpoN regulates many cell functions, such as motility, quorum sensing, and virulence in the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa often evolves rpoN-negative variants during the chronic infection in cystic fibrosis patients. It is unclear how RpoN interacts with other regulatory mechanisms to control virulence of P. aeruginosa. In this study, we show that RpoN modulates the function of PqsR, a quorum sensing receptor regulating production of virulence factors including the phenazine pyocyanin. The ∆rpoN mutant is able to synthesize 4-quinolone signal molecule HHQ but unable to activate PqsR and Pseudomonas quinolone signal (pqs) quorum sensing. The ∆rpoN mutant produces minimal level of pyocyanin and is unable to produce the anti-staphylococcal agents. Providing pqsR in trans in the ∆rpoN mutant restores its pqs quorum sensing and virulence factor production to the wild-type level. Our study provides evidence that RpoN has a regulatory effect on P. aeruginosa virulence through modulating the function of the PqsR quorum sensing regulator. Full article
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
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Open AccessArticle Effect of Surface Passivation on Photoelectrochemical Water Splitting Performance of WO3 Vertical Plate-Like Films
Catalysts 2015, 5(4), 2024-2038; doi:10.3390/catal5042024
Received: 22 October 2015 / Accepted: 17 November 2015 / Published: 24 November 2015
Cited by 5 | Viewed by 1065 | PDF Full-text (962 KB) | HTML Full-text | XML Full-text
Abstract
WO3 vertical plate-like arrays provide a direct pathway for charge transport, and thus hold great potential as working electrodes for photoelectrochemical (PEC) water splitting. However, surface recombination due to surface defects hinders the performance improvement. In this work, WO3 vertical plate-like arrays films
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WO3 vertical plate-like arrays provide a direct pathway for charge transport, and thus hold great potential as working electrodes for photoelectrochemical (PEC) water splitting. However, surface recombination due to surface defects hinders the performance improvement. In this work, WO3 vertical plate-like arrays films with HfO2 passivation layer were fabricated via a simple dip-coating method. In the images of transmission electron microscope, a fluffy layer and some small sphere particles existed on the surface of WO3 plate. X-ray photoelectron spectroscopy (XPS) showed a higher concentration of Hf element than the result of energy-dispersive X-ray spectroscopy (EDX), which means that HfO2 is rich on the surface of WO3 plates. A higher photocurrent under visible light irradiation was gained with surface passivation. Meanwhile, the results of intensity modulated photocurrent spectrum (IMPS) and incident photon to current conversion efficiency (IPCE) indicate that HfO2 passivation layer, acting as a barrier for the interfacial recombination, is responsible for the improved photoelectrochemical performance of WO3 vertical plate-like arrays film. Full article
(This article belongs to the Special Issue Photocatalytic Water Splitting)
Open AccessArticle High Rate Performance Nanocomposite Electrode of Mesoporous Manganese Dioxide/Silver Nanowires in KI Electrolytes
Nanomaterials 2015, 5(4), 1638-1653; doi:10.3390/nano5041638
Received: 7 August 2015 / Revised: 9 September 2015 / Accepted: 28 September 2015 / Published: 13 October 2015
Cited by 5 | Viewed by 993 | PDF Full-text (1601 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, manganese dioxide has become a research hotspot as an electrode material because of its low price. However, it has also become an obstacle to industrialization due to its low ratio of capacitance and the low rate performance which is caused
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In recent years, manganese dioxide has become a research hotspot as an electrode material because of its low price. However, it has also become an obstacle to industrialization due to its low ratio of capacitance and the low rate performance which is caused by the poor electrical conductivity. In this study, a KI solution with electrochemical activity was innovatively applied to the electrolyte, and we systematically investigated the rate performance of the mesoporous manganese dioxide and the composite electrode with silver nanowires in supercapacitors. The results showed that when mesoporous manganese dioxide and mesoporous manganese dioxide/silver nanowires composite were used as electrodes, the strength of the current was amplified five times (from 0.1 to 0.5 A/g), the remaining rates of specific capacitance were 95% (from 205.5 down to 197.1 F/g) and 92% (from 208.1 down to 191.7 F/g) in the KI electrolyte, and the rate performance was much higher than which in an Na2SO4 electrolyte with a remaining rate of 25% (from 200.3 down to 49.1 F/g) and 60% (from 187.2 down to 113.1 F/g). The morphology and detail structure were investigated by Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry and Nitrogen adsorption-desorption isotherms. The electrochemical performance was assessed by cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessArticle High Specific Capacitance of Polyaniline/Mesoporous Manganese Dioxide Composite Using KI-H2SO4 Electrolyte
Polymers 2015, 7(10), 1939-1953; doi:10.3390/polym7101491
Received: 19 July 2015 / Revised: 31 August 2015 / Accepted: 14 September 2015 / Published: 30 September 2015
Cited by 12 | Viewed by 1307 | PDF Full-text (3871 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The PANI/Mesoporous MnO2 composites were prepared through a simple one step method and we introduced the KI-H2SO4 solution as the electrolyte of PANI/MnO2 composites creatively. The characterization of structure, morphology, and composition are obtained by X-ray diffraction, Fourier
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The PANI/Mesoporous MnO2 composites were prepared through a simple one step method and we introduced the KI-H2SO4 solution as the electrolyte of PANI/MnO2 composites creatively. The characterization of structure, morphology, and composition are obtained by X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravity analysis, Raman spectra, and scanning electron microscope. The electrochemical performances were investigated by constant-current charge–discharge, the voltammetry curve, and alternating current (AC) impedance technique. The specific capacitance of composites is 1405 F/g, which is almost 10 times larger than MnO2 (158 F/g). We also find that the iodide concentration is closely related to the specific capacitance. Therefore, we explored the specific capacitance at different iodide concentration (0.05, 0.1, 0.2, 0.5, and 1 M), the results indicated that the specific capacitance reached a maximum value (1580 F/g) at 0.5 mol/L. Additionally, the PANI/Mesoporous MnO2 composites not only exhibited a good ratio discharge property (857 F/g) at high current density, but also revealed an excellent cycling stability after 500 cycles, which retained 90% of the original specific capacitance. Full article
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Open AccessArticle Bioassay-Guided Isolation and Identification of Xanthine Oxidase Inhibitory Constituents from the Leaves of Perilla frutescens
Molecules 2015, 20(10), 17848-17859; doi:10.3390/molecules201017848
Received: 27 August 2015 / Revised: 15 September 2015 / Accepted: 22 September 2015 / Published: 25 September 2015
Cited by 8 | Viewed by 1262 | PDF Full-text (984 KB) | HTML Full-text | XML Full-text
Abstract
Activity-directed fractionation and purification processes were employed to identify xanthine oxidase (XO) inhibitory compounds from the leaves of Perilla frutescens. The total extract was evaluated in vitro on XO inhibitory activity and in vivo in an experimental model with potassium oxonate-induced hyperuricemia
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Activity-directed fractionation and purification processes were employed to identify xanthine oxidase (XO) inhibitory compounds from the leaves of Perilla frutescens. The total extract was evaluated in vitro on XO inhibitory activity and in vivo in an experimental model with potassium oxonate-induced hyperuricemia in mice which was used to evaluate anti-hyperuricemic activity. The crude extract showed expressive urate-lowering activity results. Solvent partitioning of the total extract followed by macroporous resin column chromatography of the n-butanol extract yielded four extracts and eluted parts. Among them, only the 70% ethanol eluted part of the n-butanol extract showed strong activity and therefore was subjected to separation and purification using various chromatographic techniques. Five compounds showing potent activity were identified by comparing their spectral data with literature values to be caffeic acid, vinyl caffeate, rosmarinic acid, methyl rosmarinate, and apigenin. These results indicate that pending further study, these compounds could be used as novel natural product agents for the treatment of hyperuricemia. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Functional Characterization of New Polyketide Synthase Genes Involved in Ochratoxin A Biosynthesis in Aspergillus Ochraceus fc-1
Toxins 2015, 7(8), 2723-2738; doi:10.3390/toxins7082723
Received: 26 June 2015 / Revised: 10 July 2015 / Accepted: 17 July 2015 / Published: 24 July 2015
Cited by 4 | Viewed by 1308 | PDF Full-text (2618 KB) | HTML Full-text | XML Full-text
Abstract
Ochratoxin A (OTA), a potentially carcinogenic mycotoxin which contaminates grains, is produced by several Aspergillus species. A comparative sequence analysis of the OTA-producing Aspergillus ochraceus fc-1 strain and other Aspergillus species was performed. Two new OTA-related polyketide synthase (PKS) (AoOTApks) genes
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Ochratoxin A (OTA), a potentially carcinogenic mycotoxin which contaminates grains, is produced by several Aspergillus species. A comparative sequence analysis of the OTA-producing Aspergillus ochraceus fc-1 strain and other Aspergillus species was performed. Two new OTA-related polyketide synthase (PKS) (AoOTApks) genes were identified. The predicted amino acid sequence of AoOTApks-1 displayed high similarity to previously identified PKSs from OTA-producing A. carbonarius ITEM 5010 (67%; [PI] No. 173482) and A. niger CBS 513.88 (62%; XP_001397313). However, the predicted amino acid sequence of AoOTApks-2 displayed lower homology with A. niger CBS 513.88 (38%) and A. carbonarius ITEM 5010 (28%). A phylogenetic analysis of the β-ketosynthase and acyl-transferase domains of the AoOTApks proteins indicated that they shared a common origin with other OTA-producing species, such as A. carbonarius, A. niger, and A. westerdijkiae. A real-time reverse-transcription PCR analysis showed that the expression of AoOTApks-1 and -2 was positively correlated with the OTA concentration. The pks gene deleted mutants ∆AoOTApks-1 and ∆AoOTApks-2 produced nil and lesser OTA than the wild-type strain, respectively. Our study suggests that AoOTApks-1 could be involved in OTA biosynthesis, while AoOTApks-2 might be indirectly involved in OTA production. Full article
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Open AccessArticle A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations
Sensors 2015, 15(7), 16786-16803; doi:10.3390/s150716786
Received: 18 May 2015 / Revised: 24 June 2015 / Accepted: 8 July 2015 / Published: 10 July 2015
Cited by 3 | Viewed by 1012 | PDF Full-text (1349 KB) | HTML Full-text | XML Full-text
Abstract
On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting
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On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth’s surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 1018 Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment. Full article
(This article belongs to the Section Remote Sensors)
Open AccessArticle Ginsenoside Rd Protects SH-SY5Y Cells against 1-Methyl-4-phenylpyridinium Induced Injury
Int. J. Mol. Sci. 2015, 16(7), 14395-14408; doi:10.3390/ijms160714395
Received: 1 April 2015 / Revised: 8 June 2015 / Accepted: 17 June 2015 / Published: 24 June 2015
Cited by 11 | Viewed by 1279 | PDF Full-text (2478 KB) | HTML Full-text | XML Full-text
Abstract
Ginsenoside Rd (GSRd), one of the main active monomer compounds from the medical plant Panax ginseng, has been shown to promote neuronal survival in models of ischemic cerebral damage. As an extending study, here we examined whether GSRd could exert a
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Ginsenoside Rd (GSRd), one of the main active monomer compounds from the medical plant Panax ginseng, has been shown to promote neuronal survival in models of ischemic cerebral damage. As an extending study, here we examined whether GSRd could exert a beneficial effect in an experimental Parkinson disease (PD) model in vitro, in which SH-SY5Y cells were injured by 1-methyl-4-phenylpyridinium (MPP+), an active metabolic product of the classical Parkinsonian toxin1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Our results, from the addition of different concentrations of GSRd (1, 10 and 50 μM), showed that GSRd at 1 and 10 μM could significantly attenuate MPP+-induced cell death. This protective effect may be ascribed to its ability to reduce intracellular reactive oxygen species levels, enhance antioxidant enzymatic activities, preserve the activity of respiratory complex I, stabilize the mitochondrial membrane potential and increase intracellular ATP levels. Additionally, the PI3K/Akt survival-signaling pathway was also involved in the protective effect of GSRd. Finally, using a mouse PD model in vivo, we also found that GSRd obviously reversed the loss of tyrosine hydroxylase-positive cells in substanitia nigra induced by MPTP. Thus, our findings demonstrated that GSRd showed a significant neuro-protective effect against experimental PD models, which may involve its antioxidant effects and mitochondrial function preservation. Full article
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
Open AccessArticle An Optimization Clustering Algorithm Based on Texture Feature Fusion for Color Image Segmentation
Algorithms 2015, 8(2), 234-247; doi:10.3390/a8020234
Received: 4 April 2015 / Revised: 4 May 2015 / Accepted: 19 May 2015 / Published: 22 May 2015
Cited by 1 | Viewed by 1424 | PDF Full-text (900 KB) | HTML Full-text | XML Full-text
Abstract
We introduce a multi-feature optimization clustering algorithm for color image segmentation. The local binary pattern, the mean of the min-max difference, and the color components are combined as feature vectors to describe the magnitude change of grey value and the contrastive information of
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We introduce a multi-feature optimization clustering algorithm for color image segmentation. The local binary pattern, the mean of the min-max difference, and the color components are combined as feature vectors to describe the magnitude change of grey value and the contrastive information of neighbor pixels. In clustering stage, it gets the initial clustering center and avoids getting into local optimization by adding mutation operator of genetic algorithm to particle swarm optimization. Compared with well-known methods, the proposed method has an overall better segmentation performance and can segment image more accurately by evaluating the ratio of misclassification. Full article
(This article belongs to the Special Issue Clustering Algorithms)
Open AccessArticle Preparation and Electrochemical Characterization of Mesoporous Polyaniline-Silica Nanocomposites as an Electrode Material for Pseudocapacitors
Materials 2015, 8(4), 1369-1383; doi:10.3390/ma8041369
Received: 2 February 2015 / Revised: 11 March 2015 / Accepted: 16 March 2015 / Published: 25 March 2015
Cited by 9 | Viewed by 1448 | PDF Full-text (1314 KB) | HTML Full-text | XML Full-text
Abstract
Mesoporous polyaniline-silica nanocomposites with a full interpenetrating structure for pseudocapacitors were synthesized via the vapor phase approach. The morphology and structure of the nanocomposites were deeply investigated by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis and nitrogen adsorption-desorption tests. The
[...] Read more.
Mesoporous polyaniline-silica nanocomposites with a full interpenetrating structure for pseudocapacitors were synthesized via the vapor phase approach. The morphology and structure of the nanocomposites were deeply investigated by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis and nitrogen adsorption-desorption tests. The results present that the mesoporous nanocomposites possess a uniform particle morphology and full interpenetrating structure, leading to a continuous conductive polyaniline network with a large specific surface area. The electrochemical performances of the nanocomposites were tested in a mixed solution of sulfuric acid and potassium iodide. With the merits of a large specific surface area and suitable pore size distribution, the nanocomposite showed a large specific capacitance (1702.68 farad (F)/g) due to its higher utilization of the active material. This amazing value is almost three-times larger than that of bulk polyaniline when the same mass of active material was used. Full article
(This article belongs to the Special Issue Advances in Mesoporous Material 2015)
Open AccessReview Plasmonic Gold Nanostars for Multi-Modality Sensing and Diagnostics
Sensors 2015, 15(2), 3706-3720; doi:10.3390/s150203706
Received: 13 January 2015 / Accepted: 30 January 2015 / Published: 5 February 2015
Cited by 12 | Viewed by 1615 | PDF Full-text (2789 KB) | HTML Full-text | XML Full-text
Abstract
Gold nanostars (AuNSs) are unique systems that can provide a novel multifunctional nanoplatform for molecular sensing and diagnostics. The plasmonic absorption band of AuNSs can be tuned to the near infrared spectral range, often referred to as the “tissue optical window”, where light
[...] Read more.
Gold nanostars (AuNSs) are unique systems that can provide a novel multifunctional nanoplatform for molecular sensing and diagnostics. The plasmonic absorption band of AuNSs can be tuned to the near infrared spectral range, often referred to as the “tissue optical window”, where light exhibits minimal absorption and deep penetration in tissue. AuNSs have been applied for detecting disease biomarkers and for biomedical imaging using multi-modality methods including surface-enhanced Raman scattering (SERS), two-photon photoluminescence (TPL), magnetic resonance imaging (MRI), positron emission tomography (PET), and X-ray computer tomography (CT) imaging. In this paper, we provide an overview of the recent development of plasmonic AuNSs in our laboratory for biomedical applications and highlight their potential for future translational medicine as a multifunctional nanoplatform. Full article
Open AccessReview The Roles of Direct Recognition by Animal Lectins in Antiviral Immunity and Viral Pathogenesis
Molecules 2015, 20(2), 2272-2295; doi:10.3390/molecules20022272
Received: 28 August 2014 / Accepted: 21 January 2015 / Published: 29 January 2015
Cited by 8 | Viewed by 1745 | PDF Full-text (3659 KB) | HTML Full-text | XML Full-text
Abstract
Lectins are a group of proteins with carbohydrate recognition activity. Lectins are categorized into many families based on their different cellular locations as well as their specificities for a variety of carbohydrate structures due to the features of their carbohydrate recognition domain (CRD)
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Lectins are a group of proteins with carbohydrate recognition activity. Lectins are categorized into many families based on their different cellular locations as well as their specificities for a variety of carbohydrate structures due to the features of their carbohydrate recognition domain (CRD) modules. Many studies have indicated that the direct recognition of particular oligosaccharides on viral components by lectins is important for interactions between hosts and viruses. Herein, we aim to globally review the roles of this recognition by animal lectins in antiviral immune responses and viral pathogenesis. The different classes of mammalian lectins can either recognize carbohydrates to activate host immunity for viral elimination or can exploit those carbohydrates as susceptibility factors to facilitate viral entry, replication or assembly. Additionally, some arthropod C-type lectins were recently identified as key susceptibility factors that directly interact with multiple viruses and then facilitate infection. Summarization of the pleiotropic roles of direct viral recognition by animal lectins will benefit our understanding of host-virus interactions and could provide insight into the role of lectins in antiviral drug and vaccine development. Full article
(This article belongs to the Special Issue Lectins)
Open AccessArticle Increased ARPP-19 Expression Is Associated with Hepatocellular Carcinoma
Int. J. Mol. Sci. 2015, 16(1), 178-192; doi:10.3390/ijms16010178
Received: 7 October 2014 / Accepted: 15 December 2014 / Published: 24 December 2014
Cited by 3 | Viewed by 1626 | PDF Full-text (2239 KB) | HTML Full-text | XML Full-text
Abstract
The cAMP-regulated phosphoprotein 19 (ARPP-19) plays a key role in cell mitotic G2/M transition. Expression of ARPP-19 was increased in human hepatocellular carcinoma (HCC) compared to adjacent non-tumorous liver tissues in 36 paired liver samples, and the level of ARPP-19 in HCC tissues
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The cAMP-regulated phosphoprotein 19 (ARPP-19) plays a key role in cell mitotic G2/M transition. Expression of ARPP-19 was increased in human hepatocellular carcinoma (HCC) compared to adjacent non-tumorous liver tissues in 36 paired liver samples, and the level of ARPP-19 in HCC tissues was positively correlated with the tumor size. To determine the interrelationship between ARPP-19 expression and HCC, we silenced ARPP-19 expression in the human hepatocarcinoma HepG2 and SMMC-7721 cells using lentivirus encoding ARPP-19 siRNA. HepG2 and SMMC-7721 cells with ARPP-19 knockdown displayed lowered cell growth rate, retarded colony formation and increased arrest at the G2/M phase transition. Silencing ARPP-19 in HCC cells resulted in decreased protein levels of phospho-(Ser) CDKs substrates and increased levels of inactivated cyclin division cycle 2 (Cdc2). Therefore, ARPP-19 may play a role in HCC pathogenesis through regulating cell proliferation. Full article
(This article belongs to the collection Molecular Mechanisms of Human Liver Diseases)
Open AccessArticle 2-(1H-Benzimidazol-2-yl)-4,5,6,7-tetrahydro-2H-indazol-3-ol, a Benzimidazole Derivative, Inhibits T Cell Proliferation Involving H+/K+-ATPase Inhibition
Molecules 2014, 19(11), 17173-17186; doi:10.3390/molecules191117173
Received: 1 September 2014 / Revised: 13 October 2014 / Accepted: 21 October 2014 / Published: 24 October 2014
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Abstract
In this study, a benzimidazole derivative named BMT-1 is revealed as a potential immunomodulatory agent. BMT-1 inhibits the activity of H+/K+-ATPases from anti-CD3/CD28 activated T cells. Furthermore, inhibition the H+/K+-ATPases by use of BMT-1 should lead to intracellular acidification, inhibiting T cell proliferation.
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In this study, a benzimidazole derivative named BMT-1 is revealed as a potential immunomodulatory agent. BMT-1 inhibits the activity of H+/K+-ATPases from anti-CD3/CD28 activated T cells. Furthermore, inhibition the H+/K+-ATPases by use of BMT-1 should lead to intracellular acidification, inhibiting T cell proliferation. To explore this possibility, the effect of BMT-1 on intracellular pH changes was examined by using BCECF as a pH-dependent fluorescent dye. Interestingly, increases in the pHi were observed in activated T cells, and T cells treated with BMT-1 showed a more acidic intracellular pH. Finally, BMT-1 targeted the H+/K+-ATPases and inhibited the proliferative response of anti-CD3/CD28-stimulated T cells. A cell cycle analysis indicated that BMT-1 arrested the cell cycle progression of activated T cells from the G1 to the S phase without affecting CD25 expression or interleukin-2 (IL-2) production; treating IL-2-dependent PBMCs with BMT-1 also led to the inhibition of cell proliferation. Taken together, these findings demonstrate that BMT-1 inhibits the proliferation of T cells by interfering with H+/K+-ATPases and down-regulating intracellular pHi. This molecule may be an interesting lead compound for the development of new immunomodulatory agents. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Magnetic Properties of FeNi-Based Thin Film Materials with Different Additives
Biosensors 2014, 4(3), 189-203; doi:10.3390/bios4030189
Received: 21 April 2014 / Revised: 10 June 2014 / Accepted: 23 June 2014 / Published: 4 July 2014
Cited by 3 | Viewed by 1889 | PDF Full-text (1471 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that
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This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B. Full article
(This article belongs to the Special Issue Magnetic Biosensors)
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Open AccessArticle Spatially-Explicit Simulation Modeling of Ecological Response to Climate Change: Methodological Considerations in Predicting Shifting Population Dynamics of Infectious Disease Vectors
ISPRS Int. J. Geo-Inf. 2013, 2(3), 645-664; doi:10.3390/ijgi2030645
Received: 18 May 2013 / Revised: 17 June 2013 / Accepted: 27 June 2013 / Published: 22 July 2013
Cited by 1 | Viewed by 2563 | PDF Full-text (1170 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Poikilothermic disease vectors can respond to altered climates through spatial changes in both population size and phenology. Quantitative descriptors to characterize, analyze and visualize these dynamic responses are lacking, particularly across large spatial domains. In order to demonstrate the value of a spatially
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Poikilothermic disease vectors can respond to altered climates through spatial changes in both population size and phenology. Quantitative descriptors to characterize, analyze and visualize these dynamic responses are lacking, particularly across large spatial domains. In order to demonstrate the value of a spatially explicit, dynamic modeling approach, we assessed spatial changes in the population dynamics of Ixodes scapularis, the Lyme disease vector, using a temperature-forced population model simulated across a grid of 4 × 4 km cells covering the eastern United States, using both modeled (Weather Research and Forecasting (WRF) 3.2.1) baseline/current (2001–2004) and projected (Representative Concentration Pathway (RCP) 4.5 and RCP 8.5; 2057–2059) climate data. Ten dynamic population features (DPFs) were derived from simulated populations and analyzed spatially to characterize the regional population response to current and future climate across the domain. Each DPF under the current climate was assessed for its ability to discriminate observed Lyme disease risk and known vector presence/absence, using data from the US Centers for Disease Control and Prevention. Peak vector population and month of peak vector population were the DPFs that performed best as predictors of current Lyme disease risk. When examined under baseline and projected climate scenarios, the spatial and temporal distributions of DPFs shift and the seasonal cycle of key questing life stages is compressed under some scenarios. Our results demonstrate the utility of spatial characterization, analysis and visualization of dynamic population responses—including altered phenology—of disease vectors to altered climate. Full article
(This article belongs to the Special Issue Geovisualization and Analysis of Dynamic Phenomena)
Open AccessReview Feline Foamy Virus-Based Vectors: Advantages of an Authentic Animal Model
Viruses 2013, 5(7), 1702-1718; doi:10.3390/v5071702
Received: 1 March 2013 / Revised: 13 June 2013 / Accepted: 25 June 2013 / Published: 12 July 2013
Cited by 6 | Viewed by 2282 | PDF Full-text (355 KB) | HTML Full-text | XML Full-text
Abstract
New-generation retroviral vectors have potential applications in vaccination and gene therapy. Foamy viruses are particularly interesting as vectors, because they are not associated to any disease. Vector research is mainly based on primate foamy viruses (PFV), but cats are an alternative animal model,
[...] Read more.
New-generation retroviral vectors have potential applications in vaccination and gene therapy. Foamy viruses are particularly interesting as vectors, because they are not associated to any disease. Vector research is mainly based on primate foamy viruses (PFV), but cats are an alternative animal model, due to their smaller size and the existence of a cognate feline foamy virus (FFV). The potential of replication-competent (RC) FFV vectors for vaccination and replication-deficient (RD) FFV-based vectors for gene delivery purposes has been studied over the past years. In this review, the key achievements and functional evaluation of the existing vectors from in vitro cell culture systems to out-bred cats will be described. The data presented here demonstrate the broad application spectrum of FFV-based vectors, especially in pathogen-specific prophylactic and therapeutic vaccination using RD vectors in cats and in classical gene delivery. In the cat-based system, FFV-based vectors provide an advantageous platform to evaluate and optimize the applicability, efficacy and safety of foamy virus (FV) vectors, especially the understudied aspect of FV cell and organ tropism. Full article
(This article belongs to the Special Issue Recent Progress in Foamy Virus (FV) Research)
Open AccessArticle Quantitative Structure-Activity Relationship Studies on Indenoisoquinoline Topoisomerase I Inhibitors as Anticancer Agents in Human Renal Cell Carcinoma Cell Line SN12C
Int. J. Mol. Sci. 2012, 13(5), 6009-6025; doi:10.3390/ijms13056009
Received: 9 March 2012 / Revised: 4 May 2012 / Accepted: 11 May 2012 / Published: 18 May 2012
Cited by 6 | Viewed by 2377 | PDF Full-text (648 KB) | HTML Full-text | XML Full-text
Abstract
Topoisomerase I is important for DNA replication and cell division, making it an attractive drug target for anticancer therapy. A series of indenoisoquinolines displaying potent Top1 inhibitory activity in human renal cell carcinoma cell line SN12C were selected to establish 3D-QSAR models using
[...] Read more.
Topoisomerase I is important for DNA replication and cell division, making it an attractive drug target for anticancer therapy. A series of indenoisoquinolines displaying potent Top1 inhibitory activity in human renal cell carcinoma cell line SN12C were selected to establish 3D-QSAR models using CoMFA and CoMSIA methods. Internal and external cross-validation techniques were investigated, as well as some measures taken, including region focusing, bootstrapping and the “leave-group-out” cross-validation method. The satisfactory CoMFA model predicted a q2 value of 0.659 and an r2 value of 0.949, indicating that electrostatic and steric properties play a significant role in potency. The best CoMSIA model, based on a combination of steric, electrostatic and H-bond acceptor descriptors, predicted a q2 value of 0.523 and an r2 value of 0.902. The models were graphically interpreted by contour plots which provided insight into the structural requirements for increasing the activity of a compound, providing a solid basis for future rational design of more active anticancer agents. Full article
Open AccessArticle Modulation of the Differentiation of Dental Pulp Stem Cells by Different Concentrations of β-Glycerophosphate
Molecules 2012, 17(2), 1219-1232; doi:10.3390/molecules17021219
Received: 15 December 2011 / Revised: 17 January 2012 / Accepted: 18 January 2012 / Published: 31 January 2012
Cited by 13 | Viewed by 2831 | PDF Full-text (476 KB)
Abstract
Dentinogenesis is a necessary prerequisite for dental tissue engineering. One of the steps for dentinogenesis is to obtain large quantities of highly purified odontoblasts. Therefore, we have undertaken an experiment applying different concentrations of β-glycerophosphate (β-GP) to induce the differentiation of dental pulp
[...] Read more.
Dentinogenesis is a necessary prerequisite for dental tissue engineering. One of the steps for dentinogenesis is to obtain large quantities of highly purified odontoblasts. Therefore, we have undertaken an experiment applying different concentrations of β-glycerophosphate (β-GP) to induce the differentiation of dental pulp stem cells (DPSCs) in a long-term 28-day culture. In the meanwhile, we have studied the time- and maturation-dependent expression of matrix extracellular phosphoglycoprotein (MEPE) and that of the odontoblast-like marker-dentin sialoprotein (DSP), in order to investigate an optimized mineralized condition. Western blot results revealed that the expression of DSP became lower when accompanied by the increase of the β-GP concentration, and there was also an influence on MEPE expression when different concentrations of β-GP were applied. Meanwhile, the mineralized groups had an inhibitory function on the expression of MEPE as compared with the control group. Above all, all experimental groups successfully generated mineralized nodules by Alizarin Red S and the 5 mM β-GP group formed more mineralized nodules quantitated using the CPC extraction method. In conclusion, there is a significant modulation of the β-GP during the differentiation of the DPSCs. The degree of odontoblast differentiation is β-glycerophosphate concentration dependent. A low concentration of β-GP (5 mM) has been shown to be the optimal concentration for stimulating the maturation of the DPSCs. Moreover, MEPE accompanied with DSP clearly demonstrates the degree of the differentiation. Full article

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