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Open AccessArticle Tribological Properties of Porous PEEK Composites Containing Ionic Liquid under Dry Friction Condition
Lubricants 2017, 5(2), 19; doi:10.3390/lubricants5020019
Received: 25 April 2017 / Revised: 4 June 2017 / Accepted: 13 June 2017 / Published: 17 June 2017
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Abstract
NaCl particles were added into Polyetheretherketone (PEEK) and its composites to produce porous PEEK-based materials by washing NaCl away after the high-temperature compression molding process. After that, an ionic liquid was added into the porous materials under vacuum condition. Carbon fibers (CF), as
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NaCl particles were added into Polyetheretherketone (PEEK) and its composites to produce porous PEEK-based materials by washing NaCl away after the high-temperature compression molding process. After that, an ionic liquid was added into the porous materials under vacuum condition. Carbon fibers (CF), as reinforcement, and PTFE, as an internal solid lubricant, were employed to prepare PEEK composites. Tribological properties under dry friction condition were studied on a ring-on-disc tribo-meter. The influence of CF and PTFE on tribological properties was carefully investigated. The results indicated that, in comparison with traditional PEEK composites (CF/PTFE/PEEK), the porous PEEK composites containing ionic liquid showed much better tribological properties. It is found that CF can help PEEK form effective pores to suck in the ionic liquid resulting in a better tribological performance. CF reinforced porous PEEK containing ionic liquid (p-CF/PEEK + IL) demonstrated the lowest friction coefficient (27% of CF/PTFE/PEEK) and the lowest wear loss (only 0.9% of CF/PTFE/PEEK). Long time tribological test revealed that the wear mass loss comes from the running-in period, while its wear is negligible after this period. It is also found that the addition of PTFE has a negative influence on the tribological behaviors, especially under high sliding velocity and applied load. Full article
(This article belongs to the Special Issue Green Chemistry in Lubrication)
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Open AccessArticle A Miniature On-Chip Methane Sensor Based on an Ultra-Low Loss Waveguide and a Micro-Ring Resonator Filter
Micromachines 2017, 8(5), 160; doi:10.3390/mi8050160
Received: 1 March 2017 / Revised: 25 April 2017 / Accepted: 12 May 2017 / Published: 17 May 2017
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Abstract
A miniature methane sensor composed of a long ultra-low loss waveguide and a micro-ring resonator filter is proposed with high sensitivity and good selectivity. This sensor takes advantage of the evanescent field to implement methane concentration detection at a near infrared band (1650
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A miniature methane sensor composed of a long ultra-low loss waveguide and a micro-ring resonator filter is proposed with high sensitivity and good selectivity. This sensor takes advantage of the evanescent field to implement methane concentration detection at a near infrared band (1650 nm). In the sensor, two waveguides, a strip waveguide and a slot waveguide, are specially designed and discussed based on three common semiconductor materials, including silica, silicon nitride, and silicon. Through simulations and numerical calculations, we determine that for the strip waveguide, the optimal evanescent field ratio (EFR) is approximately 39.8%, while the resolution is 32.1 ppb using a 15-cm waveguide length. For the slot waveguide, the optimal EFR is approximately 61.6%, and the resolution is 20.8 ppb with a 15-cm waveguide length. Full article
(This article belongs to the Special Issue Optofluidics 2016)
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Open AccessArticle Alginate Oligosaccharide Prevents Acute Doxorubicin Cardiotoxicity by Suppressing Oxidative Stress and Endoplasmic Reticulum-Mediated Apoptosis
Mar. Drugs 2016, 14(12), 231; doi:10.3390/md14120231
Received: 11 September 2016 / Revised: 7 December 2016 / Accepted: 9 December 2016 / Published: 20 December 2016
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Abstract
Doxorubicin (DOX) is a highly potent chemotherapeutic agent, but its usage is limited by dose-dependent cardiotoxicity. DOX-induced cardiotoxicity involves increased oxidative stress and activated endoplasmic reticulum-mediated apoptosis. Alginate oligosaccharide (AOS) is a non-immunogenic, non-toxic and biodegradable polymer, with anti-oxidative, anti-inflammatory and anti-endoplasmic reticulum
[...] Read more.
Doxorubicin (DOX) is a highly potent chemotherapeutic agent, but its usage is limited by dose-dependent cardiotoxicity. DOX-induced cardiotoxicity involves increased oxidative stress and activated endoplasmic reticulum-mediated apoptosis. Alginate oligosaccharide (AOS) is a non-immunogenic, non-toxic and biodegradable polymer, with anti-oxidative, anti-inflammatory and anti-endoplasmic reticulum stress properties. The present study examined whether AOS pretreatment could protect against acute DOX cardiotoxicity, and the underlying mechanisms focused on oxidative stress and endoplasmic reticulum-mediated apoptosis. We found that AOS pretreatment markedly increased the survival rate of mice insulted with DOX, improved DOX-induced cardiac dysfunction and attenuated DOX-induced myocardial apoptosis. AOS pretreatment mitigated DOX-induced cardiac oxidative stress, as shown by the decreased expressions of gp91 (phox) and 4-hydroxynonenal (4-HNE). Moreover, AOS pretreatment significantly decreased the expression of Caspase-12, C/EBP homologous protein (CHOP) (markers for endoplasmic reticulum-mediated apoptosis) and Bax (a downstream molecule of CHOP), while up-regulating the expression of anti-apoptotic protein Bcl-2. Taken together, these findings identify AOS as a potent compound that prevents acute DOX cardiotoxicity, at least in part, by suppression of oxidative stress and endoplasmic reticulum-mediated apoptosis. Full article
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Open AccessArticle Simultaneous Determination of Multiple Components in Guanjiekang in Rat Plasma via the UPLC–MS/MS Method and Its Application in Pharmacokinetic Study
Molecules 2016, 21(12), 1732; doi:10.3390/molecules21121732
Received: 7 October 2016 / Revised: 9 December 2016 / Accepted: 13 December 2016 / Published: 16 December 2016
Cited by 1 | Viewed by 906 | PDF Full-text (1777 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Guanjiekang (GJK) that is formed by five medicinal herbs including Astragali Radix, Aconiti Lateralis Radix Praeparaia, Glycyrrhizae Radix et Rhizoma, Corydalis Rhizoma and Paeoniae Radix Alba was used for the treatment of rheumatoid arthritis (RA). However, the pharmacokinetic (PK) profile of
[...] Read more.
Guanjiekang (GJK) that is formed by five medicinal herbs including Astragali Radix, Aconiti Lateralis Radix Praeparaia, Glycyrrhizae Radix et Rhizoma, Corydalis Rhizoma and Paeoniae Radix Alba was used for the treatment of rheumatoid arthritis (RA). However, the pharmacokinetic (PK) profile of active components in GJK remains unclear. This study aims to evaluate the pharmacokinetic behavior of seven representative active constituents in GJK (i.e., benzoylhypaconine, benzoylmesaconine, paeoniflorin, tetrahydropalmatine, calycosin-7-glucoside, formononetin and isoliquiritigenin) after oral administration of GJK in rats. A rapid, sensitive and reliable ultra-performance liquid chromatography-tandem mass spectrometer (UPLC–MS/MS) method has been successfully developed for the simultaneous determination of these seven constituents in rat plasma. Chromatographic separation was achieved on a C18 column with a gradient elution program that consists of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.35 mL/min. Detection was performed under the multiple reaction monitoring (MRM) in the positive electrospray ionization (ESI) mode. The calibration curves exhibited good linearity (R2 > 0.99) over a wide concentration range for all constituents. The accuracies ranged from 92.9% to 107.8%, and the intra-day and inter-day precisions at three different levels were below 15%. Our PK results showed that these seven compounds were quickly absorbed after the administration of the GJK product, and Tmax ranged from 30 min to 189 min. The in vivo concentrations of paeoniflorin and isoliquiritigenin were significantly higher than the reported in vitro effective doses, indicating that they could partly contribute to the therapeutic effect of GJK. Therefore, we conclude that pharmacokinetic studies of representative bioactive chemicals after administration of complex herbal products are not only necessary but also feasible. Moreover, these seven compounds that were absorbed in vivo can be used as indicator standards for quality control and for determining pharmacokinetic behavior of herbal medicines in clinical studies. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Estimating Air Particulate Matter Using MODIS Data and Analyzing Its Spatial and Temporal Pattern over the Yangtze Delta Region
Sustainability 2016, 8(9), 932; doi:10.3390/su8090932
Received: 3 June 2016 / Revised: 4 September 2016 / Accepted: 7 September 2016 / Published: 13 September 2016
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Abstract
The deteriorating air quality in the Yangtze delta region is attracting growing public concern. In this paper, seasonal estimation models of the surface particulate matter (PM) were established by using aerosol optical thickness (AOT) retrievals from the moderate resolution imaging spectro-radiometer (MODIS) on
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The deteriorating air quality in the Yangtze delta region is attracting growing public concern. In this paper, seasonal estimation models of the surface particulate matter (PM) were established by using aerosol optical thickness (AOT) retrievals from the moderate resolution imaging spectro-radiometer (MODIS) on board NASA’s Terra satellite. The change of the regional distribution of the atmospheric mixed layer, relative humidity and meteorological elements have been taken into account in these models. We also used PM mass concentrations of ground measurements to evaluate the estimation accuracy of those models. The results show that model estimation of PM2.5 and PM10 mass concentrations were in good agreement with the ground-based observation of PM mass concentrations (p < 0.01, the R2 value of the PM2.5 concentrations experimental model for four seasons are 0.48, 0.62, 0.61 and 0.52 respectively. The R2 value of PM10 concentrations experimental model for four seasons are 0.57, 0.56, 0.64 and 0.68 respectively). At the same time, spatial and temporal variations of PM2.5 and PM10 mass concentrations were analysed over the Yangtze delta region from 2000 to 2013. The results show that PM2.5 and PM10 show a trend of increase in the Yangtze delta region from 2000 to 2013 and change periodically. The maximum mass concentration of PM2.5 and PM10 was in January–February, and the minimum was in July–August. The highest values of PM2.5 and PM10 mass concentration are in the region of urban agglomeration which is grouped to a delta-shaped region by Shanghai, Hangzhou and Nanjing, while the low values are in the forest far away from the city. PM mass concentration over main cities and rural areas increased gradually year by year, and were increasing more quickly in urban areas than in rural areas. Full article
(This article belongs to the Special Issue Air Pollution Monitoring and Sustainable Development)
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Open AccessArticle Calcium-Sensing Receptor in Human Peripheral Blood T Lymphocytes Is Involved in the AMI Onset and Progression through the NF-κB Signaling Pathway
Int. J. Mol. Sci. 2016, 17(9), 1397; doi:10.3390/ijms17091397
Received: 7 July 2016 / Revised: 28 July 2016 / Accepted: 16 August 2016 / Published: 24 August 2016
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Abstract
Acute myocardial infarction (AMI) is a condition triggered by an inflammatory process that seriously affects human health. Calcium-sensing receptor (CaSR) in T lymphocytes is involved during the inflammation reaction. However, the relationship between them is not very clear. In this study, we collected
[...] Read more.
Acute myocardial infarction (AMI) is a condition triggered by an inflammatory process that seriously affects human health. Calcium-sensing receptor (CaSR) in T lymphocytes is involved during the inflammation reaction. However, the relationship between them is not very clear. In this study, we collected human peripheral blood T lymphocytes from patients with AMI and in different stages of percutaneous coronary intervention (PCI) (at the onset of AMI, the first day after PCI (PCI-1), PCI-3, and PCI-5) to study the CaSR and NF-κB pathway protein expression, cytokine release and T cell apoptosis. The results showed that the expressions of CaSR, P-p65, Caspase-12, and the secretions of Th-1 and Th-2 type cytokines were increased at the onset of AMI, especially on the PCI-1. Meanwhile, the apoptosis rate of CD3+, CD4+ and CD8+ T lymphocytes also increased. However, from PCI-3, all the indicators began to decline. In addition, we also found that positive CaSR small interfering RNA (siRNA) transfection in T lymphocytes and NF-κB pathway blocker Bay-11-7082 reversed the increased expressions of CaSR, P-p65, Caspase-12, reduced the secretions of Th-1 and Th-2 type cytokines, and decreased T lymphocytes apoptosis rate not only in the AMI patients but also in the normal controls. All of these results indicated that CaSR in the human peripheral blood T lymphocytes were involved in the AMI onset and progression, which probably was related to the NF-κB pathway. Our study demonstrated the relationship between AMI and CaSR, and will provide new effective prevention theory and new targets for drug treatment. Full article
(This article belongs to the collection G Protein-Coupled Receptor Signaling and Regulation)
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Open AccessArticle Expression and Critical Role of Interleukin Enhancer Binding Factor 2 in Hepatocellular Carcinoma
Int. J. Mol. Sci. 2016, 17(8), 1373; doi:10.3390/ijms17081373
Received: 6 April 2016 / Revised: 5 August 2016 / Accepted: 8 August 2016 / Published: 22 August 2016
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Abstract
Interleukin enhancer binding factor 2 (ILF2), a transcription factor, regulates cell growth by inhibiting the stabilization of mRNA. Currently, its role has gained recognition as a factor in the tumorigenic process. However, until now, little has been known about the detailed role ILF2
[...] Read more.
Interleukin enhancer binding factor 2 (ILF2), a transcription factor, regulates cell growth by inhibiting the stabilization of mRNA. Currently, its role has gained recognition as a factor in the tumorigenic process. However, until now, little has been known about the detailed role ILF2 plays in hepatocellular carcinoma (HCC). In this study, we investigated the expression levels of ILF2 in HCC tissue with Western blot and immunohistochemical assays. To examine the effect of ILF2 on liver cancer cell growth and apoptosis, small interfering RNAs (siRNAs) targeting ILF2 were recombined to create lentiviral overexpression vectors. Our results showed higher expression levels of ILF2 mRNA and ILF2 protein in HCC tissue compared with matched peritumoral tissue. Expression of ILF2 may regulate cell growth and apoptosis in liver cancer cells via regulation of B-cell lymphoma 2 (Bcl-2), Bcl-2 related ovarian killer (Bok), Bcl-2-associated X protein (BAX), and cellular inhibitor of apoptosis 1 (cIAP1). Moreover, we inoculated nude mice with liver cancer cells to investigate the effect of ILF2 on tumorigenesis in vivo. As expected, a rapid growth was observed in cancer cells inoculated with a lentiviral vector coding Flag-ILF2 (Lenti-ILF2) compared with the control cells. Hence, these results promote a better understanding of ILF2’s potential role as a therapeutic target in HCC. Full article
(This article belongs to the collection Molecular Mechanisms of Human Liver Diseases)
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Open AccessArticle Potential Sources and Formations of the PM2.5 Pollution in Urban Hangzhou
Atmosphere 2016, 7(8), 100; doi:10.3390/atmos7080100
Received: 16 June 2016 / Revised: 11 July 2016 / Accepted: 12 July 2016 / Published: 28 July 2016
Cited by 1 | Viewed by 643 | PDF Full-text (3260 KB) | HTML Full-text | XML Full-text
Abstract
Continuous measurements of meteorological parameters, gaseous pollutants, particulate matters, and the major chemical species in PM2.5 were conducted in urban Hangzhou from 1 September to 30 November 2013 to study the potential sources and formations of PM2.5 pollution. The average PM
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Continuous measurements of meteorological parameters, gaseous pollutants, particulate matters, and the major chemical species in PM2.5 were conducted in urban Hangzhou from 1 September to 30 November 2013 to study the potential sources and formations of PM2.5 pollution. The average PM2.5 concentration was 69 µg·m−3, ~97% higher than the annual concentration limit in the national ambient air quality standards (NAAQS) of China. Relative humidity (RH) and wind speed (WS) were two important factors responsible for the increase of PM2.5 concentration, with the highest value observed under RH of 70%–90%. PM2.5 was in good correlation with both NO2 and CO, but not with SO2, and the potential source contribution function (PSCF) results displayed that local emissions were important potential sources contributing to the elevated PM2.5 and NO2 in Hangzhou. Thus, local vehicle emission was suggested as a major contribution to the PM2.5 pollution. Concentrations of NO2 and CO significantly increased in pollution episodes, while the SO2 concentration even decreased, implying local emission rather than region transport was the major source contributing to the formation of pollution episodes. The sum of SO42−, NO3, and NH4+ accounted for ~50% of PM2.5 in mass in pollution episodes and the NO3/EC ratios were significantly elevated, revealing that the formation of secondary inorganic species, particularly NO3, was an important contributor to the PM2.5 pollution in Hangzhou. This study highlights that controlling local pollution emissions was essential to reduce the PM2.5 pollution in Hangzhou, and the control of vehicle emission in particular should be further promoted in the future. Full article
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Open AccessArticle H2 Adsorbed Site-to-Site Electronic Delocalization within IRMOF-1: Understanding Non-Negligible Interactions at High Pressure
Materials 2016, 9(7), 578; doi:10.3390/ma9070578
Received: 12 April 2016 / Revised: 18 June 2016 / Accepted: 27 June 2016 / Published: 15 July 2016
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Abstract
Isoreticular metal organic frameworks (IRMOFs) have shown high uptake capabilities for storage of H2 (11.5 wt % at 77 K and 170 bar). A significant literature has employed fragment models and a single adsorbed H2 to identify adsorption sites within IRMOFs,
[...] Read more.
Isoreticular metal organic frameworks (IRMOFs) have shown high uptake capabilities for storage of H2 (11.5 wt % at 77 K and 170 bar). A significant literature has employed fragment models and a single adsorbed H2 to identify adsorption sites within IRMOFs, as well as the necessary adsorbate–adsorbent interactions needed to reach sufficient adsorption enthalpy for practical usage, however at high pressures it remains to be seen if H2···H2 intermolecular interactions may influence the energetics. This study focuses upon IRMOF-1 (also known as MOF-5), and examines the individual H2 stabilization energies at different sites using Möller–Plesset perturbation theory and density functional theory alongside chemical models that consist of isolated fragment models and a cubic super cell cluster consisting of both the face- and edge-cube’s of IRMOF-1. Optimization of twenty stable configurations of singly adsorbed H2 in the super-cell cluster is observed to be essential to obtain energy ordering of the five primary sites consistent with experiment and prior benchmark calculations (α >> β > γ > δ ≈ ε). To examine site-to-site interactions that may occur in the high-pressure regime, 64 co-adsorbed H2 within a super-cell cluster have been studied (a theoretical maximum of all adsorption sites, 14 wt %). There, delocalization and/or charge transfer of electrons is observed from the σ orbitals of the H2 bound at the γ positions into the σ* orbitals of H2 bound at the α sites leads to stabilization of the interaction of H2 at the γ, by 1.4 kJ/mol, respectively (using M06-2X/LANL2DZ). This effect has been confirmed to be charge transfer, and not a manifestation of enhanced dispersion at high loading, through natural bond order (NBO) analysis and by comparisons of the square of off-diagonal NBO Fock matrix elements for both density functionals that account for dispersion interactions and Hartree–Fock calculations that ignore dispersion. Full article
(This article belongs to the Section Materials for Energy Applications)
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Open AccessTechnical Note A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring
Sensors 2016, 16(2), 168; doi:10.3390/s16020168
Received: 11 September 2015 / Revised: 13 January 2016 / Accepted: 23 January 2016 / Published: 28 January 2016
Cited by 1 | Viewed by 964 | PDF Full-text (2716 KB) | HTML Full-text | XML Full-text
Abstract
In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide
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In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Iron-Mediated Homogeneous ICAR ATRP of Methyl Methacrylate under ppm Level Organometallic Catalyst Iron(III) Acetylacetonate
Polymers 2016, 8(2), 29; doi:10.3390/polym8020029
Received: 20 December 2015 / Revised: 9 January 2016 / Accepted: 19 January 2016 / Published: 26 January 2016
Cited by 8 | Viewed by 952 | PDF Full-text (878 KB) | HTML Full-text | XML Full-text
Abstract
Atom Transfer Radical Polymerization (ATRP) is an important polymerization process in polymer synthesis. However, a typical ATRP system has some drawbacks. For example, it needs a large amount of transition metal catalyst, and it is difficult or expensive to remove the metal catalyst
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Atom Transfer Radical Polymerization (ATRP) is an important polymerization process in polymer synthesis. However, a typical ATRP system has some drawbacks. For example, it needs a large amount of transition metal catalyst, and it is difficult or expensive to remove the metal catalyst residue in products. In order to reduce the amount of catalyst and considering good biocompatibility and low toxicity of the iron catalyst, in this work, we developed a homogeneous polymerization system of initiators for continuous activator regeneration ATRP (ICAR ATRP) with just a ppm level of iron catalyst. Herein, we used oil-soluble iron (III) acetylacetonate (Fe(acac)3) as the organometallic catalyst, 1,1′-azobis (cyclohexanecarbonitrile) (ACHN) with longer half-life period as the thermal initiator, ethyl 2-bromophenylacetate (EBPA) as the initiator, triphenylphosphine (PPh3) as the ligand, toluene as the solvent and methyl methacrylate (MMA) as the model monomer. The factors related with the polymerization system, such as concentration of Fe(acac)3 and ACHN and polymerization kinetics, were investigated in detail at 90 °C. It was found that a polymer with an acceptable molecular weight distribution (Mw/Mn = 1.43 at 45.9% of monomer conversion) could be obtained even with 1 ppm of Fe(acac)3, making it needless to remove the residual metal in the resultant polymers, which makes such an ICAR ATRP process much more industrially attractive. The “living” features of this polymerization system were further confirmed by chain-extension experiment. Full article
(This article belongs to the Special Issue Controlled/Living Radical Polymerization)
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Open AccessArticle Synthesis of Chiral Chalcone Derivatives Catalyzed by the Chiral Cinchona Alkaloid Squaramide
Molecules 2014, 19(12), 19491-19500; doi:10.3390/molecules191219491
Received: 3 November 2014 / Revised: 13 November 2014 / Accepted: 13 November 2014 / Published: 25 November 2014
Cited by 2 | Viewed by 1871 | PDF Full-text (267 KB) | HTML Full-text | XML Full-text
Abstract
An effective method has been developed for the preparation of novel chiral chalcone derivatives under mild conditions from the easily accessible starting materials nitromethane and chalcone derivatives 2. The corresponding products were obtained in moderate yields with excellent enantioselectivities (up to 99%). Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Spatial Variation of Regional Sustainable Development and its Relationship to the Allocation of Science and Technology Resources
Sustainability 2014, 6(9), 6400-6417; doi:10.3390/su6096400
Received: 27 May 2014 / Revised: 14 August 2014 / Accepted: 26 August 2014 / Published: 15 September 2014
Cited by 3 | Viewed by 1284 | PDF Full-text (1155 KB) | HTML Full-text | XML Full-text
Abstract
With the increasing of labor salaries, the RMB exchange rate, resource product prices and requirements of environmental protection, inexpensive labor and land are no longer the decisive factor of regional competitiveness. From this perspective, China needs to shift from the extensive development mode
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With the increasing of labor salaries, the RMB exchange rate, resource product prices and requirements of environmental protection, inexpensive labor and land are no longer the decisive factor of regional competitiveness. From this perspective, China needs to shift from the extensive development mode to the sustainable development mode. Science and technology resources rational allocation is one of the key issues in sustainable development. Based on the counties (districts) data of Zhejiang Province in China, this paper portrays the spatial variation of regional sustainable development level of this area. This paper finds that counties tend to cluster in groups with the same sustainable development level, and this agglomeration trend has been enforced during the past several years. It then testifies to the relationship between the allocation of science and technology resources and local sustainable development, identifies science and technology human resources, financial resources and environmental resource are positively related to local sustainable development, except government financial support. The economic level has a negative relationship with regional sustainable development. This is because the development of the Zhejiang economy grown at the expense of the environment and ecosystem. Some advice is given according to the empirical analysis result. Full article
(This article belongs to the Section Economic, Business and Management Aspects of Sustainability)
Open AccessArticle BMP4 Protects Rat Pulmonary Arterial Smooth Muscle Cells from Apoptosis by PI3K/AKT/Smad1/5/8 Signaling
Int. J. Mol. Sci. 2014, 15(8), 13738-13754; doi:10.3390/ijms150813738
Received: 8 June 2014 / Revised: 21 July 2014 / Accepted: 1 August 2014 / Published: 8 August 2014
Cited by 11 | Viewed by 1707 | PDF Full-text (4995 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Bone morphogenetic protein-4 (BMP4), a member of the transforming growth factor β (TGF-β) family of growth factors, is activated and increased under hypoxic conditions, which plays an important role in the progression of pulmonary arterial hypertension (PAH). Previous studies have shown that BMP4
[...] Read more.
Bone morphogenetic protein-4 (BMP4), a member of the transforming growth factor β (TGF-β) family of growth factors, is activated and increased under hypoxic conditions, which plays an important role in the progression of pulmonary arterial hypertension (PAH). Previous studies have shown that BMP4 is involved in the regulation of proliferation, differentiation, migration and apoptosis of various cell types. However, the precise mechanisms involved in the regulation of pulmonary artery smooth muscle cells (PASMCs) in PAH are still incompletely understood. It has been reported that AKT is a critical regulator of cell survival and vascular remodeling. Therefore, there may be crosstalk between BMP4 anti-apoptotic processes and PI3K/AKT survival effect in rat PASMCs. To test this hypothesis, we performed confocal, cell viability measurement, mitochondrial potential, real-time polymerase chain reaction (PCR), and Western blot analysis to determine the role of BMP4 on cell survival and apoptosis. We found that hypoxia up-regulated the expression of BMP4. BMP4 promoted cell survival, reduced mitochondrial depolarization, and increased the expression of Bcl-2 and procaspase-3 in PASMCs under serum-deprived condition. These effects were reversed by PI3K/AKT inhibitors (LY294002 and wortmannin). Thus, these findings indicate that BMP4 protects PASMCs from apoptosis at least in part, mediated via the PI3K/AKT pathway. Full article
(This article belongs to the Special Issue Signalling Molecules and Signal Transduction in Cells 2014)
Open AccessArticle Long Non-Coding RNA HOTAIR Promotes Cell Migration and Invasion via Down-Regulation of RNA Binding Motif Protein 38 in Hepatocellular Carcinoma Cells
Int. J. Mol. Sci. 2014, 15(3), 4060-4076; doi:10.3390/ijms15034060
Received: 2 January 2014 / Revised: 20 February 2014 / Accepted: 27 February 2014 / Published: 6 March 2014
Cited by 43 | Viewed by 2532 | PDF Full-text (3179 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Long non-coding RNA HOTAIR exerts regulatory functions in various biological processes in cancer cells, such as proliferation, apoptosis, mobility, and invasion. We previously found that HOX transcript antisense RNA (HOTAIR) is a negative prognostic factor and exhibits oncogenic activity in hepatocellular carcinoma (HCC).
[...] Read more.
Long non-coding RNA HOTAIR exerts regulatory functions in various biological processes in cancer cells, such as proliferation, apoptosis, mobility, and invasion. We previously found that HOX transcript antisense RNA (HOTAIR) is a negative prognostic factor and exhibits oncogenic activity in hepatocellular carcinoma (HCC). In this study, we aimed to investigate the role and molecular mechanism of HOTAIR in promoting HCC cell migration and invasion. Firstly, we profiled its gene expression pattern by microarray analysis of HOTAIR loss in Bel-7402 HCC cell line. The results showed that 129 genes were significantly down-regulated, while 167 genes were significantly up-regulated (fold change >2, p < 0.05). Bioinformatics analysis indicated that RNA binding proteins were involved in this biological process. HOTAIR suppression using RNAi strategy with HepG2 and Bel-7402 cells increased the mRNA and protein expression levels of RNA binding motif protein 38 (RBM38). Moreover, the expression levels of RBM38 in HCC specimens were significantly lower than paired adjacent noncancerous tissues. In addition, knockdown of HOTAIR resulted in a decrease of cell migration and invasion, which could be specifically rescued by down-regulation of RBM38. Taken together, HOTAIR could promote migration and invasion of HCC cells by inhibiting RBM38, which indicated critical roles of HOTAIR and RBM38 in HCC progression. Full article
(This article belongs to the collection Molecular Mechanisms of Human Liver Diseases)
Open AccessArticle The Anti-Lung Cancer Activities of Steroidal Saponins of P. polyphylla Smith var. chinensis (Franch.) Hara through Enhanced Immunostimulation in Experimental Lewis Tumor-Bearing C57BL/6 Mice and Induction of Apoptosis in the A549 Cell Line
Molecules 2013, 18(10), 12916-12936; doi:10.3390/molecules181012916
Received: 15 August 2013 / Revised: 8 October 2013 / Accepted: 9 October 2013 / Published: 17 October 2013
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Abstract
P. polyphylla Smith var. chinensis (Franch.) Hara (PPSCFH) has been used as medicinal Paris for the prevention and treatment of cancers in China for thousands of years. Its main components, steroidal saponins (PRS), have been confirmed to inhibit tumor growth. In the present
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P. polyphylla Smith var. chinensis (Franch.) Hara (PPSCFH) has been used as medicinal Paris for the prevention and treatment of cancers in China for thousands of years. Its main components, steroidal saponins (PRS), have been confirmed to inhibit tumor growth. In the present study, the immunostimulation of PRS was investigated in Lewis bearing-C57BL/6 mice while the induction of apoptosis in A549 cells was also studied. The treatment with PRS (2.5, 5.0 and 7.5 mg/kg) significantly inhibited tumor, volume, and weight in the C57BL/6 mice. The rates of inhibition of PRS (at 2.5, 5.0 and 7.5 mg/kg) were 26.49 ± 17.30%, 40.32 ± 18.91% and 54.94 ± 16.48%, respectively. The spleen and thymus indexes were increased remarkably, while the levels of inflammatory cytokines including TNF-α, IL-8 and IL-10 in serum were decreased according to ELISA assays. For A549 cells, Hoechst 33342 staining and annexin V/PI by flow cytometry showed that PRS (0.25, 0.50 and 0.75 mg/mL) induced nuclear changes of A549 cells with DNA condensation and fragmentations of chromatin, as well as inducing apoptosis. Furthermore, PRS could also attenuate the over-generation of intracellular ROS. Western blotting analysis showed a significant decrease on the expressions of proinflammatory cytokines MCP-1, IL-6 and TGF-β1, as well as cell adhesion molecule ICAM-1, by treatment with PRS. Our results demonstrated that the inhibition of PRS on tumor growth might be associated with the amelioration of inflammation responses, induction of apoptosis, as well as the decrease of ROS. These results suggested that PRS implied a potential therapeutic effect in the lung cancer treatment. Full article
Open AccessArticle One-Pot Synthesis of Novel Chiral β-Amino Acid Derivatives by Enantioselective Mannich Reactions Catalyzed by Squaramide Cinchona Alkaloids
Molecules 2013, 18(6), 6142-6152; doi:10.3390/molecules18066142
Received: 1 April 2013 / Revised: 13 May 2013 / Accepted: 16 May 2013 / Published: 23 May 2013
Cited by 9 | Viewed by 2604 | PDF Full-text (320 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
An efficient one-pot synthesis of novel β-amino acid derivatives containing a thiadiazole moiety was developed using a chiral squaramide cinchona alkaloid as organocatalyst. The reactions afforded chiral β-amino acid derivatives in moderate yields and with moderate to excellent enantioselectivities. The present
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An efficient one-pot synthesis of novel β-amino acid derivatives containing a thiadiazole moiety was developed using a chiral squaramide cinchona alkaloid as organocatalyst. The reactions afforded chiral β-amino acid derivatives in moderate yields and with moderate to excellent enantioselectivities. The present study demonstrated for the first time the use of a Mannich reaction catalyzed by a chiral bifunctional organocatalyst for the one-pot synthesis of novel β-amino acid derivatives bearing a 1,3,4-thiadiazole moiety on nitrogen. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Monocyte Chemotactic Protein-1 Promotes the Myocardial Homing of Mesenchymal Stem Cells in Dilated Cardiomyopathy
Int. J. Mol. Sci. 2013, 14(4), 8164-8178; doi:10.3390/ijms14048164
Received: 6 February 2013 / Revised: 8 March 2013 / Accepted: 26 March 2013 / Published: 15 April 2013
Cited by 9 | Viewed by 2438 | PDF Full-text (555 KB) | HTML Full-text | XML Full-text
Abstract
Dilated cardiomyopathy (DCM) is the most common form of non-ischemic cardiomyopathy that leads to heart failure. Mesenchymal stem cells (MSCs) are under active investigation currently as a potential therapy for DCM. However, little information is available about the therapeutic potential of intravenous administration
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Dilated cardiomyopathy (DCM) is the most common form of non-ischemic cardiomyopathy that leads to heart failure. Mesenchymal stem cells (MSCs) are under active investigation currently as a potential therapy for DCM. However, little information is available about the therapeutic potential of intravenous administration of MSCs for DCM. Moreover, how MSCs home to the myocardium in DCM is also unclear. DCM was induced by intraperitoneally administering Doxorubicin and MSCs or vehicles were infused through the internal jugular vein. Cardiac functions including the percentage of fractional shortening, left ventricular diastolic dimension, left ventricular end-diastolic pressure, and left ventricular maximum dp/dt were evaluated by echocardiographic and hemodynamic studies. Fibrosis was determined by Masson’s trichrome staining. The mRNA expression levels of monocyte chemotactic protein-1 (MCP-1), stromal cell-derived factor-1 (SDF-1), macrophage inflammatory protein-1α (MIP-1α), and monocyte chemotactic protein-3 (MCP-3) were determined using real time polymerase chain reactions and the protein expression level of MCP-1 was detected with Western blot. The MSCs expression of C-C chemokine receptor type 2 (CCR2), a MCP-1 receptor, was confirmed by Western blot and flow cytometry analysis. The chemotactic effects of MCP-1/CCR2 were checked by assessing the migration in vitro and in vivo. MSCs transplantation improved the cardiac function and decreased the myocardial fibrosis of mice with DCM. MCP-1 was up-regulated in dilated myocardial tissue both at the mRNA and protein level while SDF-1, MIP-1α and MCP-3 remain unchanged. CCR2 was present in MSCs. MCP-1 promoted MSCs migration in vitro while CCR2 inhibition decreased the migration of MCP-1 to the dilated heart. This study provides direct evidences that peripheral intravenous infusion of MSCs can support the functional recovery of DCM. In addition, novel insights into the myocardial homing factor of MSCs in DCM are presented. Modulation of MCP-1/CCR2 signaling system might be a novel therapeutic strategy for DCM. Full article
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
Open AccessArticle A Fast and Sensitive Quantitative Lateral Flow Immunoassay for Cry1Ab Based on a Novel Signal Amplification Conjugate
Sensors 2012, 12(9), 11684-11696; doi:10.3390/s120911684
Received: 5 July 2012 / Revised: 6 August 2012 / Accepted: 20 August 2012 / Published: 27 August 2012
Cited by 21 | Viewed by 3161 | PDF Full-text (743 KB) | HTML Full-text | XML Full-text
Abstract
A novel lateral flow immunoassay (LFIA) signal amplification strategy for the detection of Cry1Ab based on amplification via a polylysine (PL) chain and biotin-streptavidin system (BSAS) is described. In this system, multiple fluorescence dyes (FL) were directly coated on the surface of PL
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A novel lateral flow immunoassay (LFIA) signal amplification strategy for the detection of Cry1Ab based on amplification via a polylysine (PL) chain and biotin-streptavidin system (BSAS) is described. In this system, multiple fluorescence dyes (FL) were directly coated on the surface of PL and conjugated with antibody via the BSAS for construction of novel signal amplification (FLPL-BSAS-mAb1) conjugates, in which FL, PL and BSAS were employed to improve the sensitivity of LFIA. Compared with conventional LFIA, the sensitivity of FLPL-BSAS-mAb1-based LFIA was increased by approximately 100-fold. Quantified linearity was achieved in the value range of 0–1,000 pg/mL. The limit of detection (LOD) was reached 10 pg/mL after optimization of reaction conditions. To our knowledge, this represents one of the most sensitive LFIA for Cry1Ab yet reported. Furthermore, the detection time for this method was about 10 min. Therefore, it should be an attractive alternative compared to conventional immunoassays in routine control for Cry1Ab. Full article
Open AccessArticle N-Substituted 5-Chloro-6-phenylpyridazin-3(2H)-ones: Synthesis, Insecticidal Activity Against Plutella xylostella (L.) and SAR Study
Molecules 2012, 17(8), 9413-9420; doi:10.3390/molecules17089413
Received: 5 July 2012 / Revised: 27 July 2012 / Accepted: 30 July 2012 / Published: 6 August 2012
Cited by 2 | Viewed by 1863 | PDF Full-text (235 KB) | HTML Full-text | XML Full-text
Abstract
A series of N-substituted 5-chloro-6-phenylpyridazin-3(2H)-one derivatives were synthesized based on our previous work; all compounds were characterized by spectral data and tested for in vitro insecticidal activity against Plutella xylostella. The results showed that the synthesized pyridazin-3(2H)-one
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A series of N-substituted 5-chloro-6-phenylpyridazin-3(2H)-one derivatives were synthesized based on our previous work; all compounds were characterized by spectral data and tested for in vitro insecticidal activity against Plutella xylostella. The results showed that the synthesized pyridazin-3(2H)-one compounds possessed good insecticidal activities, especially the compounds 4b, 4d, and 4h which showed > 90% activity at 100 mg/L. The structure-activity relationships (SAR) for these compounds were also discussed. Full article
Open AccessArticle Rapid Synthesis and Antiviral Activity of (Quinazolin-4-Ylamino)Methyl-Phosphonates Through Microwave Irradiation
Int. J. Mol. Sci. 2012, 13(6), 6730-6746; doi:10.3390/ijms13066730
Received: 31 March 2012 / Revised: 8 May 2012 / Accepted: 8 May 2012 / Published: 1 June 2012
Cited by 6 | Viewed by 2110 | PDF Full-text (352 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
This study describes the simple synthesis of new (quinazolin-4-ylamino) methylphosphonates via microwave irradiation. Substituted-2-aminobenzonitrile reacted with 1,1-dimethoxy-N,N-dimethylmethanamine at a reflux condition to obtain N'-(substituted-2-cyanophenyl)-N,N-dimethylformamidine (1). The subsequent reaction of this intermediate product with α-aminophosphonate
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This study describes the simple synthesis of new (quinazolin-4-ylamino) methylphosphonates via microwave irradiation. Substituted-2-aminobenzonitrile reacted with 1,1-dimethoxy-N,N-dimethylmethanamine at a reflux condition to obtain N'-(substituted-2-cyanophenyl)-N,N-dimethylformamidine (1). The subsequent reaction of this intermediate product with α-aminophosphonate (2) in a solution containing glacial acetic acid in 2-propanol through microwave irradiation resulted in the formation of (quinazolin-4-ylamino)methyl-phosphonate derivatives 3a to 3x, which were unequivocally characterized by the spectral data and elemental analysis. The influence of the reaction conditions on the yield of 3a was investigated to optimize the synthetic conditions. The relative optimal conditions for the synthesis of 3a include a 1:1 molar ratio of N’-(2-cyanophenyl)-N,N-dimethylformamidine to diethyl amino(phenyl)methylphosphonate and a 4:1 volume ratio of isopropanol to HOAc in the solvent mixture, at a reaction temperature of 150 °C, with a microwave power of 100 W and a corresponding pressure of 150 psi for 20 min in the microwave synthesizer. The yield of 3a was approximately 79%, whereas those of 3b to 3x were approximately 77% to 86%. Some of the synthesized compounds displayed weak to good anti-Tobacco mosaic virus (TMV) activity. Full article
Open AccessArticle Synthesis and Bioactivity of Pyrazole Acyl Thiourea Derivatives
Molecules 2012, 17(5), 5139-5150; doi:10.3390/molecules17055139
Received: 11 April 2012 / Revised: 19 April 2012 / Accepted: 19 April 2012 / Published: 3 May 2012
Cited by 21 | Viewed by 3345 | PDF Full-text (269 KB)
Abstract
Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine) and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in
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Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine) and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl isothiocyanates 5. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds. The synthesized compound were unequivocally characterized by IR, 1H-NMR, 13C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antifungal activity tests. Full article
Open AccessArticle The Effects of G-CSF on Proliferation of Mouse Myocardial Microvascular Endothelial Cells
Int. J. Mol. Sci. 2011, 12(2), 1306-1315; doi:10.3390/ijms12021306
Received: 31 December 2010 / Revised: 7 February 2011 / Accepted: 18 February 2011 / Published: 22 February 2011
Viewed by 3329 | PDF Full-text (207 KB) | HTML Full-text | XML Full-text
Abstract
This paper explores the effect of granulocyte colony-stimulating factor (G-CSF) on mouse myocardial microvascular endothelial cell (CMECs) proliferation. CMECs were harvested from C57/BL6 mice. CMECs were cultured in medium containing G-CSF (0 ng/mL, 20 ng/mL, 40 ng/mL, 60 ng/mL) for five days. Proliferative
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This paper explores the effect of granulocyte colony-stimulating factor (G-CSF) on mouse myocardial microvascular endothelial cell (CMECs) proliferation. CMECs were harvested from C57/BL6 mice. CMECs were cultured in medium containing G-CSF (0 ng/mL, 20 ng/mL, 40 ng/mL, 60 ng/mL) for five days. Proliferative activity of CMECs was examined by CCK-8 method. Hypoxia inducible factor-1 (HIF-1) and p53 expression levels was determined from the mRNA obtained by reverse transcription polymerase chain reaction (RT-PCR). Results showed that the purity quotient of the CMECs, which were cultured by the method of modified myocardial tissue explant culture, was higher than 95%. Compared with control untreated cells, the proliferative activity of CMECs and the expression level of HIF-1 mRNA in these cells were enhanced by G-CSF treatment, whereas the expression level of p53 mRNA was markedly reduced. It may be concluded that G-CSF could promote the proliferative activity of CMECs, which might be mediated by upregulation of HIF-1 and downregulation of p53. Full article
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
Open AccessArticle Synthesis and Antiviral Bioactivity of Chiral Thioureas Containing Leucine and Phosphonate Moieties
Molecules 2010, 15(8), 5112-5123; doi:10.3390/molecules15085112
Received: 18 June 2010 / Revised: 26 July 2010 / Accepted: 27 July 2010 / Published: 29 July 2010
Cited by 18 | Viewed by 5348 | PDF Full-text (164 KB)
Abstract
A series of novel chiral thioureas 3a-n bearing leucine and phosphonate moieties were synthesized in excellent yields. The structures of the compounds were completely characterized by elemental analysis,IR, 1H-, 13C-, 31P- and 19F-NMR spectral data. A half-leaf
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A series of novel chiral thioureas 3a-n bearing leucine and phosphonate moieties were synthesized in excellent yields. The structures of the compounds were completely characterized by elemental analysis, IR, 1H-, 13C-, 31P- and 19F-NMR spectral data. A half-leaf method was used to determine the in vivo protective and curative efficacies of the title products against tobacco mosaic virus (TMV). The compounds 3l and 3n displayed good in vivo protection and curative effects against TMV with inhibitory rates of 60.1, 62.8% (protection) and 56.7, 53.6% (curative) at 0.5 mg/mL, respectively. To the best of our knowledge, this is the first report on the antiviral activity of chiral thioureas containing leucine and phosphonate moieties. Full article
Open AccessArticle Synthesis and Antifungal Activity of 5-Chloro-6-Phenylpyridazin-3(2H)-one Derivatives
Molecules 2009, 14(9), 3676-3687; doi:10.3390/molecules14093676
Received: 27 July 2009 / Revised: 13 September 2009 / Accepted: 16 September 2009 / Published: 18 September 2009
Cited by 13 | Viewed by 7142 | PDF Full-text (486 KB)
Abstract
An effective method has been developed for the preparation under mild conditions of novel pyridazine derivatives from the easily accessible starting materials mucochloric acid and benzene. All the synthesized compounds were fully characterized and some of them displayed good antifungal activities against G.
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An effective method has been developed for the preparation under mild conditions of novel pyridazine derivatives from the easily accessible starting materials mucochloric acid and benzene. All the synthesized compounds were fully characterized and some of them displayed good antifungal activities against G. zeae, F. oxysporum and C. mandshurica in preliminary antifungal activity tests. Full article
Open AccessArticle Design and Evaluation of a Wireless Sensor Network Based Aircraft Strength Testing System
Sensors 2009, 9(6), 4195-4210; doi:10.3390/s90604195
Received: 31 March 2009 / Revised: 9 April 2009 / Accepted: 13 April 2009 / Published: 3 June 2009
Cited by 22 | Viewed by 10744 | PDF Full-text (938 KB) | HTML Full-text | XML Full-text
Abstract
The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The
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The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN) technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST) system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system. Full article
(This article belongs to the Special Issue Wireless Sensor Technologies and Applications)
Open AccessArticle Simulation Study of Nano Aqueous Flow Sensor Based on Amperometric Measurement
Sensors 2006, 6(5), 473-479; doi:10.3390/s6050473
Received: 10 November 2005 / Revised: 13 March 2006 / Accepted: 17 March 2006 / Published: 6 April 2006
Cited by 3 | Viewed by 5111 | PDF Full-text (70 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, a novel nano aqueous flow sensor which consists of two closelyspaced amperometric sensors is investigated by digital simulation. The simulation resultsindicate that the ratio of the responses of two closely spaced amperometric sensors is onlyrelated to flow rates in the
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In this paper, a novel nano aqueous flow sensor which consists of two closelyspaced amperometric sensors is investigated by digital simulation. The simulation resultsindicate that the ratio of the responses of two closely spaced amperometric sensors is onlyrelated to flow rates in the channel, insensitive to the analyte concentration in the solution.By comparing the output of two amperometric sensors, the flow rate in the channel can bededuced. It is not necessary to determine the analyte concentration in advance. Thesimulation results show it is able to detect flow rate by in the range of several nano-liters perminute when the distance between the working electrodes of two amperometric sensors is200 nm and the cross-section of the channel is 1 μm x 1 μm. Full article
Open AccessArticle Classification of Chinese Yellow Wines by ChemometricAnalysis of Cyclic Voltammogram of Copper Electrodes
Sensors 2005, 5(12), 529-536; doi:10.3390/s5120529
Received: 16 November 2005 / Accepted: 27 November 2005 / Published: 7 December 2005
Cited by 13 | Viewed by 4818 | PDF Full-text (126 KB) | HTML Full-text | XML Full-text
Abstract
A Chinese yellow wine classification method is proposed based on chemometricanalysis of voltammogram of copper electrode. The main components in Chinese yellowwine are alcohol, amino acids and carbon hydrates. In strong alkaline solution copperelectrode shows rich voltammetric responses to these components. Principal componentanalysis
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A Chinese yellow wine classification method is proposed based on chemometricanalysis of voltammogram of copper electrode. The main components in Chinese yellowwine are alcohol, amino acids and carbon hydrates. In strong alkaline solution copperelectrode shows rich voltammetric responses to these components. Principal componentanalysis is employed to analyse voltammetric response of copper electrode to six Chinesewine samples in strong alkaline solution. The score plots show good discrimination of thesewine samples. In order to compress the original voltammetric data, a windowed time slicingmethod is investigated in this study. It greatly reduces the input data number and theresulted PCA plot still has good discrimination ability. Full article

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