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Open AccessArticle Preparation and Properties of a Novel Microcrystalline Cellulose-Filled Composites Based on Polyamide 6/High-Density Polyethylene
Materials 2017, 10(7), 808; doi:10.3390/ma10070808
Received: 13 May 2017 / Revised: 2 July 2017 / Accepted: 10 July 2017 / Published: 16 July 2017
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Abstract
In the present study, lithium chloride (LiCl) was utilized as a modifier to reduce the melting point of polyamide 6 (PA6), and then 15 wt % microcrystalline cellulose (MCC) was compounded with low melting point PA6/high-density polyethylene (HDPE) by hot pressing. Crystallization analysis
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In the present study, lithium chloride (LiCl) was utilized as a modifier to reduce the melting point of polyamide 6 (PA6), and then 15 wt % microcrystalline cellulose (MCC) was compounded with low melting point PA6/high-density polyethylene (HDPE) by hot pressing. Crystallization analysis revealed that as little as 3 wt % LiCl transformed the crystallographic forms of PA6 from semi-crystalline to an amorphous state (melting point: 220 °C to none), which sharply reduced the processing temperature of the composites. LiCl improved the mechanical properties of the composites, as evidenced by the fact that the impact strength of the composites was increased by 90%. HDPE increased the impact strength of PA6/MCC composites. In addition, morphological analysis revealed that incorporation of LiCl and maleic anhydride grafted high-density polyethylene (MAPE) improved the interfacial adhesion. LiCl increased the glass transition temperature of the composites (the maximum is 72.6 °C). Full article
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Open AccessArticle Unsupervised Fault Diagnosis of a Gear Transmission Chain Using a Deep Belief Network
Sensors 2017, 17(7), 1564; doi:10.3390/s17071564
Received: 26 May 2017 / Revised: 29 June 2017 / Accepted: 30 June 2017 / Published: 4 July 2017
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Abstract
Artificial intelligence (AI) techniques, which can effectively analyze massive amounts of fault data and automatically provide accurate diagnosis results, have been widely applied to fault diagnosis of rotating machinery. Conventional AI methods are applied using features selected by a human operator, which are
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Artificial intelligence (AI) techniques, which can effectively analyze massive amounts of fault data and automatically provide accurate diagnosis results, have been widely applied to fault diagnosis of rotating machinery. Conventional AI methods are applied using features selected by a human operator, which are manually extracted based on diagnostic techniques and field expertise. However, developing robust features for each diagnostic purpose is often labour-intensive and time-consuming, and the features extracted for one specific task may be unsuitable for others. In this paper, a novel AI method based on a deep belief network (DBN) is proposed for the unsupervised fault diagnosis of a gear transmission chain, and the genetic algorithm is used to optimize the structural parameters of the network. Compared to the conventional AI methods, the proposed method can adaptively exploit robust features related to the faults by unsupervised feature learning, thus requires less prior knowledge about signal processing techniques and diagnostic expertise. Besides, it is more powerful at modelling complex structured data. The effectiveness of the proposed method is validated using datasets from rolling bearings and gearbox. To show the superiority of the proposed method, its performance is compared with two well-known classifiers, i.e., back propagation neural network (BPNN) and support vector machine (SVM). The fault classification accuracies are 99.26% for rolling bearings and 100% for gearbox when using the proposed method, which are much higher than that of the other two methods. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle Hydrogen Evolution Reaction Property in Alkaline Solution of Molybdenum Disulfide Modified by Surface Anchor of Nickel–Phosphorus Coating
Metals 2017, 7(6), 211; doi:10.3390/met7060211
Received: 3 May 2017 / Revised: 1 June 2017 / Accepted: 3 June 2017 / Published: 7 June 2017
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Abstract
Molybdenum disulfide (MoS2) is unfavorable for practical application in the hydrogen evolution reaction (HER) process due to its inert basal surface, inferior conductivity, and limited amount of active edge sites. For the purpose of enhancing the HER performance of this catalyst,
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Molybdenum disulfide (MoS2) is unfavorable for practical application in the hydrogen evolution reaction (HER) process due to its inert basal surface, inferior conductivity, and limited amount of active edge sites. For the purpose of enhancing the HER performance of this catalyst, the HER activity of its basal surface should be increased. Herein, three types of nickel-phosphorus (Ni–P) coatings—namely, low phosphorus (LP), medium phosphorus (MP) and high phosphorus (HP) —were anchored onto the surfaces of MoS2 nanoparticles via an electroless plating process; thus, three Ni–P/MoS2 composites (Ni–LP/MoS2, Ni–MP/MoS2, and Ni–HP/MoS2) were fabricated. Crystal structures, morphologies, chemical components, and HER performances of each in an alkaline solution were characterized. Both Ni–LP/MoS2 and Ni–MP/MoS2 showed a crystal nature, while the amorphous feature for Ni–HP/MoS2 was validated. The three Ni–P/MoS2 composites exhibited a higher HER activity than the pure MoS2. The HER performance of the Ni–MP/MoS2 composite was more outstanding than those of other two composites, which could be attributed to the presence of metastable nickel phosphides, and the excellent conductivity of Ni–MP coating anchored on the basal surface of MoS2. Full article
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Open AccessArticle Investigation into the Effect of Atmospheric Particulate Matter (PM2.5 and PM10) Concentrations on GPS Signals
Sensors 2017, 17(3), 508; doi:10.3390/s17030508
Received: 2 January 2017 / Revised: 1 March 2017 / Accepted: 2 March 2017 / Published: 3 March 2017
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Abstract
The Global Positioning System (GPS) has been widely used in navigation, surveying, geophysical and geodynamic studies, machine guidance, etc. High-precision GPS applications such as geodetic surveying need millimeter and centimeter level accuracy. Since GPS signals are affected by atmospheric effects, methods of correcting
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The Global Positioning System (GPS) has been widely used in navigation, surveying, geophysical and geodynamic studies, machine guidance, etc. High-precision GPS applications such as geodetic surveying need millimeter and centimeter level accuracy. Since GPS signals are affected by atmospheric effects, methods of correcting or eliminating ionospheric and tropospheric bias are needed in GPS data processing. Relative positioning can be used to mitigate the atmospheric effect, but its efficiency depends on the baseline lengths. Air pollution is a serious problem globally, especially in developing countries that causes health problems to humans and damage to the ecosystem. Respirable suspended particles are coarse particles with a diameter of 10 micrometers or less, also known as PM10. Moreover, fine particles with a diameter of 2.5 micrometers or less are known as PM2.5. GPS signals travel through the atmosphere before arriving at receivers on the Earth’s surface, and the research question posed in this paper is: are GPS signals affected by the increased concentration of the PM2.5/PM10 particles? There is no standard model of the effect of PM2.5/PM10 particles on GPS signals in GPS data processing, although an approximate generic model of non-gaseous atmospheric constituents (<1 mm) can be found in the literature. This paper investigates the effect of the concentration of PM2.5/PM10 particles on GPS signals and validates the aforementioned approximate model with a carrier-to-noise ratio (CNR)-based empirical method. Both the approximate model and the empirical results show that the atmospheric PM2.5/PM10 particles and their concentrations have a negligible effect on GPS signals and the effect is comparable with the noise level of GPS measurements. Full article
(This article belongs to the Section Remote Sensors)
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Open AccessArticle DFT Investigation of the Effects of Coexisting Cations and Complexing Reagents on Ni(II) Adsorption by a Polyvinylidene Fluoride-Type Chelating Membrane Bearing Poly(Amino Phosphonic Acid) Groups
Metals 2017, 7(2), 61; doi:10.3390/met7020061
Received: 29 November 2016 / Accepted: 10 February 2017 / Published: 17 February 2017
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Abstract
A polyvinylidene fluoride (PVDF)-type chelating membrane bearing poly(amino phosphonic acid) groups, denoted as ethylenediamine tetra(methylene phosphonic acid) (EDTMPA)-tetrabutyl orthotitanate (TBOT)/PVDF, was employed to remove Ni(II) from the aqueous solution. The effects of coexisting Ca(II), Pb(II), citrate, nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA)
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A polyvinylidene fluoride (PVDF)-type chelating membrane bearing poly(amino phosphonic acid) groups, denoted as ethylenediamine tetra(methylene phosphonic acid) (EDTMPA)-tetrabutyl orthotitanate (TBOT)/PVDF, was employed to remove Ni(II) from the aqueous solution. The effects of coexisting Ca(II), Pb(II), citrate, nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA) on the Ni(II) adsorption by this chelating membrane were revealed using density functional theory (DFT) calculations. Pb(II) showed a more detrimental effect than Ca(II) on the Ni(II) uptake; EDTA interfered with the capture of Ni(II) more remarkably than citrate and NTA. The results derived from DFT calculations were consistent with the experimental data. Ni(II) and Pb(II) showed more excellent affinity to the EDTMPA-TBOT/PVDF membrane than Ca(II). The stabilities between Ni(II) and the [EDTMPA-TBOT]7− chelating ligand of the membrane and those between Ni(II) and the three aforementioned complexing reagents followed the sequence: [Ni(II)-(EDTMPA-TBOT)]5− > Ni(II)-EDTA > Ni(II)-NTA > Ni(II)-citrate. The complexation between Ni(II) and the chelating membrane was prominent with the presence of citrate, NTA and EDTA. Full article
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Open AccessReview A Review on Phytochemistry and Pharmacology of Cortex Periplocae
Molecules 2016, 21(12), 1702; doi:10.3390/molecules21121702
Received: 1 November 2016 / Revised: 30 November 2016 / Accepted: 1 December 2016 / Published: 10 December 2016
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Abstract
Cortex Periplocae, as a traditional Chinese herbal medicine, has been widely used for autoimmune diseases, especially rheumatoid arthritis. Due to its potential pharmaceutical values, more studies about the biological activities of Cortex Periplocae have been conducted recently. Meanwhile, the adverse reaction of
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Cortex Periplocae, as a traditional Chinese herbal medicine, has been widely used for autoimmune diseases, especially rheumatoid arthritis. Due to its potential pharmaceutical values, more studies about the biological activities of Cortex Periplocae have been conducted recently. Meanwhile, the adverse reaction of Cortex Periplocae is not a negligible problem in clinic. In this article, we reviewed a series of articles and summarized the recent studies of Cortex Periplocae in the areas of phytochemistry and pharmacology. More than 100 constituents have been isolated and identified from Cortex Periplocae, including steroids, cardiac glycosides, terpenoids, and fatty acid compounds. The crude extracts of Cortex Periplocae and its active compounds exhibit various biological activities, such as cardiotonic effect, anticancer action, and anti-inflammatory effect. This paper aims to provide an overall review on the bioactive ingredients, pharmacological effect, and toxicity of this plant. Furthermore, this review suggests investigating and developing new clinical usages according to the above pharmacological effects. Full article
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Open AccessArticle Chemical Compositions of Ligusticum chuanxiong Oil and Lemongrass Oil and Their Joint Action against Aphis citricola Van Der Goot (Hemiptera: Aphididae)
Molecules 2016, 21(10), 1359; doi:10.3390/molecules21101359
Received: 6 September 2016 / Revised: 9 October 2016 / Accepted: 10 October 2016 / Published: 12 October 2016
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Abstract
In order to develop novel botanical insecticides, the joint action of Ligusticum chuanxiong oil (LCO) and lemongrass oil (LO) against Aphis citricola van der Goot was determined systematically indoors and outdoors. The chemical profiles of LCO and LO as determined by gas chromatography–mass
[...] Read more.
In order to develop novel botanical insecticides, the joint action of Ligusticum chuanxiong oil (LCO) and lemongrass oil (LO) against Aphis citricola van der Goot was determined systematically indoors and outdoors. The chemical profiles of LCO and LO as determined by gas chromatography–mass spectrometry (GC-MS) analysis revealed that the main compounds from LCO were (Z)-ligustilide (44.58%) and senkyunolide A (26.92%), and that of LO were geranial (42.16%) and neral (32.58%), respectively. The mixture of LCO and LO showed significant synergy against A. citricola, with a common-toxicity coefficient (CTC) value of 221.46 at the optimal ratio of LCO to LO (4:1, w:w). Based on the results of solvents and emulsifiers screening, L. chuanxiong oil·Lemongrass oil 20% emulsifiable concentrate (20% LCO·LO EC) was developed, and its stability was confirmed with tests of cold and thermal storage. Field trials indicated that the insecticidal activity of the diluted 20% LCO·LO EC (1000 fold dilution) was comparable to conventional pesticide (20% imidacloprid EC) on A. citricola seven days after application. Thus, the mixture of LCO and LO has the potential to be further developed as a botanical pesticide. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Spatial and Temporal Variations of PM2.5 and Its Relation to Meteorological Factors in the Urban Area of Nanjing, China
Int. J. Environ. Res. Public Health 2016, 13(9), 921; doi:10.3390/ijerph13090921
Received: 23 June 2016 / Revised: 28 August 2016 / Accepted: 5 September 2016 / Published: 16 September 2016
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Abstract
The serious air pollution problem has aroused widespread public concerns in China. Nanjing city, as one of the famous cities of China, is faced with the same situation. This research aims to investigate spatial and temporal distribution characteristics of fine particulate matter (PM
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The serious air pollution problem has aroused widespread public concerns in China. Nanjing city, as one of the famous cities of China, is faced with the same situation. This research aims to investigate spatial and temporal distribution characteristics of fine particulate matter (PM2.5) and the influence of weather factors on PM2.5 in Nanjing using Spearman-Rank analysis and the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) method. Hourly PM2.5 observation data and daily meteorological data were collected from 1 April 2013 to 31 December 2015. The spatial distribution result shows that the Maigaoqiao site suffered the most serious pollution. Daily PM2.5 concentrations in Nanjing varied from 7.3 μg/m3 to 336.4 μg/m3. The highest concentration was found in winter and the lowest in summer. The diurnal variation of PM2.5 increased greatly from 6 to 10 a.m. and after 6 p.m., while the concentration exhibited few variations in summer. In addition, the concentration was slightly higher on weekends compared to weekdays. PM2.5 was found to exhibit a reversed relation with wind speed, relative humidity, and precipitation. Although temperature had a positive association with PM2.5 in most months, a negative correlation was observed during the whole period. Additionally, a high concentration was mainly brought with the wind with a southwest direction and several relevant factors are discussed to explain the difference of the impacts of diverse wind directions. Full article
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Open AccessArticle Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China
Forests 2016, 7(1), 12; doi:10.3390/f7010012
Received: 5 October 2015 / Revised: 11 December 2015 / Accepted: 23 December 2015 / Published: 2 January 2016
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Abstract
Subtropical evergreen broad-leaved forest (EBLF) is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of
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Subtropical evergreen broad-leaved forest (EBLF) is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG) ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height) within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration. Full article
Open AccessArticle Folate Deficiency Decreases Apoptosis of Endometrium Decidual Cells in Pregnant Mice via the Mitochondrial Pathway
Nutrients 2015, 7(3), 1916-1932; doi:10.3390/nu7031916
Received: 19 January 2015 / Revised: 18 February 2015 / Accepted: 4 March 2015 / Published: 13 March 2015
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Abstract
It is well known that maternal folate deficiency results in adverse pregnancy outcomes. In addition to aspects in embryonic development, maternal uterine receptivity and the decidualization of stromal cells is also very important for a successful pregnancy. In this study, we focused on
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It is well known that maternal folate deficiency results in adverse pregnancy outcomes. In addition to aspects in embryonic development, maternal uterine receptivity and the decidualization of stromal cells is also very important for a successful pregnancy. In this study, we focused on endometrium decidualization and investigated whether apoptosis, which is essential for decidualization, was impaired. Flow cytometry and TUNEL detection revealed that apoptosis of mouse endometrium decidual cells was suppressed in the dietary folate-deficient group on Days 7 and 8 of pregnancy (Day 1 = vaginal plug) when decidua regression is initiated. The endometrium decidual tissue of the folate deficiency group expressed less Bax compared to the normal diet group while they had nearly equal expression of Bcl2 protein. Further examination revealed that the mitochondrial transmembrane potential (ΔΨm) decreased, and the fluorescence of diffuse cytoplasmic cytochrome c protein was detected using laser confocal microscopy in normal decidual cells. However, no corresponding changes were observed in the folate-deficient group. Western blotting analyses confirmed that more cytochrome c was released from mitochondria in normal decidual cells. Taken together, these results demonstrated that folate deficiency could inhibit apoptosis of decidual cells via the mitochondrial apoptosis pathway, thereby restraining decidualization of the endometrium and further impairing pregnancy. Full article
Open AccessArticle Small Mushrooms for Big Business? Gaps in the Sustainable Management of Non-Timber Forest Products in Southwest China
Sustainability 2014, 6(10), 6847-6861; doi:10.3390/su6106847
Received: 30 May 2014 / Revised: 17 September 2014 / Accepted: 23 September 2014 / Published: 30 September 2014
Cited by 4 | Viewed by 1515 | PDF Full-text (1536 KB) | HTML Full-text | XML Full-text
Abstract
The challenge of managing forests for the production of commercial non-timber forest products (NTFPs) lies in promoting economic development by maintaining and even increasing production while simultaneously maintaining or improving ecological conditions. The discussion of forest management therefore encompasses a wide range of
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The challenge of managing forests for the production of commercial non-timber forest products (NTFPs) lies in promoting economic development by maintaining and even increasing production while simultaneously maintaining or improving ecological conditions. The discussion of forest management therefore encompasses a wide range of social, economic, political, and ecological questions. Empirically, it is clear that both market and government failure can lead to unsustainable management in commercial NTFP use. How can we manage the market and at the same time formulate good policies? Taking cases from Southwest China, this paper critically examines the current development of NTFP commercialization in the mountainous region of Southwest China. It focuses particularly on three pieces of research on mushroom collection and marketing. By examining empirical data, the paper analyzes current gaps in the policy and the market in mountainous areas in the context of promoting sustainable use of NTFP. It examines the market structure from the perspective of market failure and explores the government’s failure to promote commercial NTFPs. We recommend economic and political decentralization, capacity building, and government investment as means to improve sustainable management. Full article
Open AccessArticle Local Dynamics Driving Forest Transition: Insights from Upland Villages in Southwest China
Forests 2014, 5(2), 214-233; doi:10.3390/f5020214
Received: 31 October 2013 / Revised: 13 December 2013 / Accepted: 16 January 2014 / Published: 23 January 2014
Cited by 16 | Viewed by 2013 | PDF Full-text (1233 KB) | HTML Full-text | XML Full-text
Abstract
China has experienced extensive forest transition, from net deforestation to net forestation. Existing theories have highlighted economic growth, the intensification of agriculture and forest scarcity as the pathways of this transition, and studies, in particular from China, have also highlighted the contribution of
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China has experienced extensive forest transition, from net deforestation to net forestation. Existing theories have highlighted economic growth, the intensification of agriculture and forest scarcity as the pathways of this transition, and studies, in particular from China, have also highlighted the contribution of a huge state afforestation program and the improved implementation and enforcement of forest protection policy and law. However, few studies have paid attention to local dynamics to provide a contextualized understanding of how forest transition has taken place at the local level and the significance of local factors in this change. This paper examines forest transition pathways in two villages in China. We consider the historical perspective and compare their local dynamics and variations to reach an understanding of the process of forest recovery at the local level. The results show that state forestry policies, including afforestation policy and tenure reform, arguably contribute to forest increase, while local processes including livelihood change and institutional factors play a key role in driving and shaping forest transition. We argue that there is a need for local-level studies and recommend including local institutions in forest transition analysis, contextualizing the socio-ecological interactions within the broader concept of political economy. Full article
Open AccessArticle Sparse Signal Recovery from Fixed Low-Rank Subspace via Compressive Measurement
Algorithms 2013, 6(4), 871-882; doi:10.3390/a6040871
Received: 16 November 2013 / Revised: 11 December 2013 / Accepted: 11 December 2013 / Published: 17 December 2013
Cited by 2 | Viewed by 2429 | PDF Full-text (515 KB) | HTML Full-text | XML Full-text
Abstract
This paper designs and evaluates a variant of CoSaMP algorithm, for recovering the sparse signal s from the compressive measurement v=A(Uw+s) given a fixed low-rank subspace spanned by U. Instead of firstly recovering the
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This paper designs and evaluates a variant of CoSaMP algorithm, for recovering the sparse signal s from the compressive measurement v = A(Uw+s) given a fixed low-rank subspace spanned by U. Instead of firstly recovering the full vector then separating the sparse part from the structured dense part, the proposed algorithm directly works on the compressive measurement to do the separation. We investigate the performance of the algorithm on both simulated data and video compressive sensing. The results show that for a fixed low-rank subspace and truly sparse signal the proposed algorithm could successfully recover the signal only from a few compressive sensing (CS) measurements, and it performs better than ordinary CoSaMP when the sparse signal is corrupted by additional Gaussian noise. Full article
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Open AccessArticle Deforestation and Changes in Landscape Patterns from 1979 to 2006 in Suan County, DPR Korea
Forests 2013, 4(4), 968-983; doi:10.3390/f4040968
Received: 12 August 2013 / Revised: 13 September 2013 / Accepted: 5 November 2013 / Published: 13 November 2013
Cited by 6 | Viewed by 2049 | PDF Full-text (2467 KB) | HTML Full-text | XML Full-text
Abstract
The Democratic People’s Republic of Korea (DPR Korea) suffered considerable upland deforestation during the 1990s, yet its consequences remain relatively unknown. This paper examines this deforestation and resulting land-use change patterns by analysis of Landsat satellite images from 1979, 1992, 2001 and 2006
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The Democratic People’s Republic of Korea (DPR Korea) suffered considerable upland deforestation during the 1990s, yet its consequences remain relatively unknown. This paper examines this deforestation and resulting land-use change patterns by analysis of Landsat satellite images from 1979, 1992, 2001 and 2006 in Suan County, Hwanghae Province, DPR Korea. Results show that there has been significant closed canopy forest loss and a dramatic expansion of agricultural land during this period. Most forestlands were converted to farmland during 1992 and 2001. Food shortages, along with fuelwood and timber extraction, are considered to be the main drivers of deforestation. Landscape analysis also showed that closed canopy forests have been severely fragmented and degraded. These research findings make a contribution to an insufficient body of literature on environmental issues in DPR Korea and helps to establish a baseline for monitoring land-use and land-cover changes in the country. Full article
Open AccessArticle A Facile Synthesis of Functionalized Dispirooxindole Derivatives via a Three-Component 1,3-Dipolar Cycloaddition Reaction
Molecules 2013, 18(5), 5142-5154; doi:10.3390/molecules18055142
Received: 3 April 2013 / Revised: 26 April 2013 / Accepted: 27 April 2013 / Published: 3 May 2013
Cited by 7 | Viewed by 2236 | PDF Full-text (355 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
An efficient synthesis of novel dispirooxindoles has been achieved through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and an α-amino acid with the dipolarophile 5-benzylideneimidazolidine-2,4-dione. The improved procedure features mild reaction conditions, high yields,
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An efficient synthesis of novel dispirooxindoles has been achieved through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and an α-amino acid with the dipolarophile 5-benzylideneimidazolidine-2,4-dione. The improved procedure features mild reaction conditions, high yields, high diastereoselectivities, a one-pot procedure and operational simplicity. Full article
Open AccessArticle Synthesis and Field Evaluation of the Sex Pheromone Analogues to Soybean Pod Borer Leguminivora glycinivorella
Molecules 2012, 17(10), 12140-12150; doi:10.3390/molecules171012140
Received: 4 September 2012 / Revised: 17 September 2012 / Accepted: 21 September 2012 / Published: 16 October 2012
Cited by 2 | Viewed by 2503 | PDF Full-text (246 KB) | HTML Full-text | XML Full-text
Abstract
In order to develop efficient lures for soybean pod borer Leguminivora glycinivorella (Matsumura) in China, (E,E)-8,10-dodecadienyl acetate (EE-8,10-12:Ac), the main component of the pheromone of L. glycinivorella, and 12 structurally-related compounds were synthesised in good overall yields, regiospecificities,
[...] Read more.
In order to develop efficient lures for soybean pod borer Leguminivora glycinivorella (Matsumura) in China, (E,E)-8,10-dodecadienyl acetate (EE-8,10-12:Ac), the main component of the pheromone of L. glycinivorella, and 12 structurally-related compounds were synthesised in good overall yields, regiospecificities, and stereo-selectivities via coupling reactions catalysed by Li2CuCl4. The effect of different synthetic compounds, alone or in combination with EE-8,10-12:Ac, on numbers of captured L. glycinivorella males was evaluated. EE-8,10-12:Ac, (E)-10-dodecenyl acetate (E-10-12:Ac), (E)-8-dodecenol (E-8-12:OH), tetradecyl acetate (14:Ac), and (Z)-9-tetradecenyl acetate (Z-9-14:Ac) alone displayed different attractiveness to L. glycinivorella males. 14:Ac, E-8-12:OH, E-10-12:Ac, (E,E)-8,10-dodecadienal (EE-8,10-12:Ald), (E)-8-dodecenal (E-8-12:Ald), (E)-10-dodecenal (E-10-12:Ald) and Z-9-14:Ac all showed a synergistic effect to EE-8,10-12:Ac at certain dosages. The binary mixtures of EE-8,10-12:Ac and E-10-12:Ald, Z-9-14:Ac,14:Ac, E-8-12:Ald, EE-8,10-12:Ald, E-8-12:OH, or E-10-12:Ac in suitable ratios give 17.00-, 10.98-, 10.67-, 6.73-, 5.54-, 4.30- and 4.50-fold increases in trap catch, respectively, over the standard pheromone lure, and as novel pheromone blends, demonstrated potential use in pheromone traps to monitor or control L. glycinivorella populations in China. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Effect of β,β-Dimethylacrylshikonin on Inhibition of Human Colorectal Cancer Cell Growth in Vitro and in Vivo
Int. J. Mol. Sci. 2012, 13(7), 9184-9193; doi:10.3390/ijms13079184
Received: 28 May 2012 / Revised: 2 July 2012 / Accepted: 9 July 2012 / Published: 23 July 2012
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Abstract
In traditional Chinese medicine, shikonin and its derivatives, has been used in East Asia for several years for the prevention and treatment of several diseases, including cancer. We previously identified that β,β-dimethylacrylshikonin (DA) could inhibit hepatocellular carcinoma growth. In the present study, we
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In traditional Chinese medicine, shikonin and its derivatives, has been used in East Asia for several years for the prevention and treatment of several diseases, including cancer. We previously identified that β,β-dimethylacrylshikonin (DA) could inhibit hepatocellular carcinoma growth. In the present study, we investigated the inhibitory effects of DA on human colorectal cancer (CRC) cell line HCT-116 in vitro and in vivo. A viability assay showed that DA could inhibit tumor cell growth in a time- and dose-dependent manner. Flow cytometry showed that DA blocks the cell cycle at G0/G1 phase. Western blotting results demonstrated that the induction of apoptosis by DA correlated with the induction of pro-apoptotic proteins Bax, and Bid, and a decrease in the expression of anti-apoptotic proteins Bcl-2 and Bcl-xl. Furthermore, treatment of HCT-116 bearing nude mice with DA significantly retarded the growth of xenografts. Consistent with the results in vitro, the DA-mediated suppression of HCT-116 xenografts correlated with Bax and Bcl-2. Taken together, these results suggest that DA could be a novel and promising approach to the treatment of CRC. Full article
Open AccessArticle Oral Administration of Apigenin Inhibits Metastasis through AKT/P70S6K1/MMP-9 Pathway in Orthotopic Ovarian Tumor Model
Int. J. Mol. Sci. 2012, 13(6), 7271-7282; doi:10.3390/ijms13067271
Received: 27 April 2012 / Revised: 28 May 2012 / Accepted: 29 May 2012 / Published: 13 June 2012
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Abstract
Apigenin, a flavonoid commonly present in the daily diet, is known for its potential anti-tumor properties. However, the effect of apigenin via oral administration on tumor growth and metastasis remains unknown. In this study we developed an orthotopic ovarian tumor model in nude
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Apigenin, a flavonoid commonly present in the daily diet, is known for its potential anti-tumor properties. However, the effect of apigenin via oral administration on tumor growth and metastasis remains unknown. In this study we developed an orthotopic ovarian tumor model in nude mice to test the effect of apigenin oral administration, and showed that apigenin inhibited the micrometastasis of cancer cells in the animal tumor model. To understand the mechanism of apigenin in inhibiting metastasis, we found that apigenin greatly inhibited MMP-9 expression and p-AKT and p-p70S6K1 levels in the tumor tissues compared to the control group. We further demonstrated that the downregulation of MMP-9 by apigenin was mediated by the AKT/p70S6K1 pathway. These findings help to address the question with common interests to the public of whether oral uptake of flavonoids is effective in preventing cancer. Our results demonstrate for the first time that oral uptake of apigenin can inhibit tumor metastasis through MMP-9 expression using the orthotopic ovarian tumor model. Full article
(This article belongs to the Section Biochemistry, Molecular and Cellular Biology)
Open AccessCommunication Synthesis and Antifungal Activity of Carabrone Derivatives
Molecules 2010, 15(9), 6485-6492; doi:10.3390/molecules15096485
Received: 6 July 2010 / Revised: 11 August 2010 / Accepted: 23 August 2010 / Published: 16 September 2010
Cited by 10 | Viewed by 4089 | PDF Full-text (269 KB)
Abstract
Nine derivatives 6-14 of carabrone (1) were synthesized and tested in vitro against Colletotrichum lagenarium Ell et Halst using the spore germination method. Among all of the derivatives, compounds 6-8 and 12 showed more potent antifungal activity than
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Nine derivatives 6-14 of carabrone (1) were synthesized and tested in vitro against Colletotrichum lagenarium Ell et Halst using the spore germination method. Among all of the derivatives, compounds 6-8 and 12 showed more potent antifungal activity than 1. Structure-activity relationships (SAR) demonstrated that the γ-lactone was necessary for the antifungal activity of 1, and the substituents on the C-4 position of 1 could significantly affect the antifungal activity. Full article

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