Since cancer stem cells(CSCs)were first identified in leukemia in 1994,they have been considered promising therapeutic targets for cancer therapy.These cells have self-renewal capacity and differentiation potential an...Since cancer stem cells(CSCs)were first identified in leukemia in 1994,they have been considered promising therapeutic targets for cancer therapy.These cells have self-renewal capacity and differentiation potential and contribute to multiple tumor malignancies,such as recurrence,metastasis,heterogeneity,multidrug resistance,and radiation resistance.The biological activities of CSCs are regulated by several pluripotent transcription factors,such as OCT4,Sox2,Nanog,KLF4,and MYC.In addition,many intracellular signaling pathways,such as Wnt,NF-κB(nuclear factor-κB),Notch,Hedgehog,JAK-STAT(Janus kinase/signal transducers and activators of transcription),PI3K/AKT/mTOR(phosphoinositide 3-kinase/AKT/mammalian target of rapamycin),TGF(transforming growth factor)/SMAD,and PPAR(peroxisome proliferator-activated receptor),as well as extracellular factors,such as vascular niches,hypoxia,tumor-associated macrophages,cancer-associated fibroblasts,cancer-associated mesenchymal stem cells,extracellular matrix,and exosomes,have been shown to be very important regulators of CSCs.Molecules,vaccines,antibodies,and CAR-T(chimeric antigen receptor T cell)cells have been developed to specifically target CSCs,and some of these factors are already undergoing clinical trials.This review summarizes the characterization and identification of CSCs,depicts major factors and pathways that regulate CSC development,and discusses potential targeted therapy for CSCs.展开更多
Chinese mitten crab （Eriocheir sinensis） has higher commercial value as food source than any other species of Eriocheir in China. To evaluate the germplasm resources and characterize the genetic diversity and popula...Chinese mitten crab （Eriocheir sinensis） has higher commercial value as food source than any other species of Eriocheir in China. To evaluate the germplasm resources and characterize the genetic diversity and population structure of the crabs in different water systems, two stocks and two farming populations were assessed with 25 polymorphic microsallite loci available in public GenBank. Basic statistics showed that the average observed heterozygosity （Ho） amongst populations ranged from 0.5789 to 0.6824. However, a remarkable presence of inbreeding and heterozygote deficiencies were observed. To analyze population structure, pairwise FST coefficients explained only -10.3% variability from the subdivision of mitten crab populations, the remaining variability stems from the subdivision within subpopulations. Although the four populations had slight differentiation, different allelic frequencies resulted in distinct population structures. Two stocks and one farming population were clustered together to the phylogenetic branch of Yangtze crab, with an approximate membership of 95%. Whereas, another farming population was clustered singly to the phylogenetic branch of the Liaohe crab, with a membership of 97.1%. The tests for individual admixture showed that Yangtze crab had probably been contaminated with individuals from other water systems. Genetic relationships between populations also supported the conclusion that Yangtze crab and Liaohe crab had different gene pools in spite of the origins of the same species.展开更多
Using monthly precipitation and temperature data from national meteorological stations, 90 m resolution DEM and a digital vector map of modern glaciers from the Chinese Glacier Inventory, the glacier mass balance and ...Using monthly precipitation and temperature data from national meteorological stations, 90 m resolution DEM and a digital vector map of modern glaciers from the Chinese Glacier Inventory, the glacier mass balance and glacier runoff in the Tarim River Basin (TRB), China, were estimated based on a monthly degree-day model for 1961–2006. The results suggest that the modified monthly degree-day model can simulate the long-term changes in glacier mass balance and glacier runoff, which have been confirmed by short-term observation data and other results in literatures. The characteristics and trends of mass balance and glacier runoff variation were analyzed. It was found that the mean annual glacier mass balance during 1961–2006 was ?139.2 mm per year and the cumulative mass balance over the 46 year period was ?6.4 m in the TRB. The glacier mass balance displayed a clear decreasing trend over the entire TRB during 1961–2006. The average annual glacier runoff in the TRB was 144.16×108 m3 for 1961–2006. The results also show that glacier runoff has increased in the last 46 years, especially since the 1990s with 85.7% of the increased river flow being derived from the increased glacier runoff caused by loss of ice mass. Over the entire TRB, glacier runoff accounts for 41.5% of the total river flow during 1961–2006. The impact of glacier runoff on river flow has increased in the TRB as a result of glacier shrinkage.展开更多
Leaf senescence as an active process is essential for plant survival and reproduction.However,premature senility is harmful to agricultural production.In this study,a rice mutant,named as psl3 (presescing leaf 3) isol...Leaf senescence as an active process is essential for plant survival and reproduction.However,premature senility is harmful to agricultural production.In this study,a rice mutant,named as psl3 (presescing leaf 3) isolated from EMS-treated Jinhui 10,displays obvious premature senility features both in morphological and physiological level.Genetic analysis showed that mutant trait was controlled by a single dominant gene (PSL3),which was located on rice chromosome 7 between SSR marker c7sr1 and InDel marker ID10 with an interval of 53.5 kb.The result may be useful for the isolation of the PSL3 gene.展开更多
Inflammatory bowel disease （IBD） is an intestinal immune-dysfunctional disease worldwide whose prevalence increasing in Asia including China. It is a chronic disease of the gastrointestinal tract with unknown cause....Inflammatory bowel disease （IBD） is an intestinal immune-dysfunctional disease worldwide whose prevalence increasing in Asia including China. It is a chronic disease of the gastrointestinal tract with unknown cause. Exosomes are small vesicles in various body fluids. They have diameters of 40-120 nm, and one of their functions is long-distance transfer of various sub- stances. In this study, we investigated the contents of salivary exosomes in patients with IBD and in healthy controls to explore a new biomarker in patients with IBD. In this study, whole saliva was obtained from patients with IBD （ulcerative colitis （UC）, n = 37; Crohn＇s disease （CD）, n = 11） and apparently healthy individuals （HC, n = 10）. Salivary exosomes were extracted from samples, and the proteins within the exosomes were iden- tified by liquid chromatograph-mass spectrometer （LC- MS/MS）. The results showed that more than 2000 proteins were detected in salivary exosomes from patients with IBD. Through gene ontology analysis, we found that proteasome subunit alpha type 7 （PSMA7） showed especially marked differences between patients with IBD and the healthy controls, in that its expression level was much higher in the CD and UC groups. This exosomal protein is related to proteasome activity and inflamma- tory responses. So we conclude that in this research,salivary exosomal PSMA7 was present at high levels in salivary exosomes from subjects with IBD. It can be a very promising biomarker to release the patients from the pain of colonoscopy.展开更多
The pro-inflammation factor high-mobility group box protein 1 （HMGB1） has been implicated in the pathogenesis of asthma. In this study, we used a murine model of chronic asthma to evaluate the effects of HMGB 1 on a...The pro-inflammation factor high-mobility group box protein 1 （HMGB1） has been implicated in the pathogenesis of asthma. In this study, we used a murine model of chronic asthma to evaluate the effects of HMGB 1 on airway remodeling. Female BALB/c mice were randomly divided into four groups： control, ovalbumin （OVA） asthmatic, OVA＋ isotype antibody and OVA＋anti-HMGB 1 antibody. Anti-HMGB 1 antibody therapy was started on day 21 and was administered three times per week for 6 weeks before intranasal challenge with OVA. In this mouse model, HMGB1 expression is significantly elevated. The anti-HMGB1 antibody group exhibited decreased levels of immunoglobulin E （IgE） and inflammatory mediators and reduced inflammatory cell accumulation, airway hyperresponsiveness （AHR）, mucus synthesis, smooth muscle thickness and lung collagen content compared with the OVA groups. Treatment with HMGB1 increased proliferation, migration, collagen secretion and a-smooth muscle actin （SMA） expression in MRC-5 ceils. Treatment with the HMGB1/IL-1β complex significantly increased the expression and secretion of transforming growth factor （TGF-βl）, matrix metalloproteinase （MMP）-9 and vascular endothelial growth factor （VEGF）. Altogether, these results suggest that blocking HMGB1 activity may reverse airway remodeling by suppressing airway inflammation and modulating lung fibroblast phenotype and activation.展开更多
Macrophage-mediated inflammation compromises bone repair in diabetic patients.Electrical signaling cues are known to regulate macrophage functions.However,the biological effects of electrical microenvironment from cha...Macrophage-mediated inflammation compromises bone repair in diabetic patients.Electrical signaling cues are known to regulate macrophage functions.However,the biological effects of electrical microenvironment from charged biomaterials on the immune response for regulating osteogenesis under diabetic conditions remain to be elucidated.Herein the endogeneous electrical microenvironment of native bone tissue was recapitulated by fabricating a ferroelectric BaTiO_(3)/poly(vinylidene fluoridetrifluoroethylene)(BTO/P(VDF-TrFE))nanocomposite membrane.In vitro,the polarized BaTiO_(3)/poly(vinylidene fluoridetrifluoroethylene)(BTO/P(VDF-TrFE))nanocomposite membranes inhibited high glucose-induced M1-type inflammation,by effecting changes in cell morphology,M1 marker expression and pro-inflammatory cytokine secretion in macrophages.This led to enhanced osteogenic differentiation of human bone marrow mesenchymal stem cells(BM-MSCs).In vivo,the biomimetic electrical microenvironment recapitulated by the polarized nanocomposite membranes switched macrophage phenotype from the pro-inflammatory(M1)into the pro-healing(M2)phenotype,which in turn enhanced bone regeneration in rats with type 2 diabetes mellitus.Mechanistic studies revealed that the biomimetic electrical microenvironment attenuated pro-inflammatory M1 macrophage polarization under hyperglycemic conditions by suppressing expression of AKT2 and IRF5 within the PI3K-AKT signaling pathway,thereby inducing favorable osteo-immunomodulatory effects.Our study thus provides fundamental insights into the biological effects of restoring the electrical microenvironment conducive for osteogenesis under DM conditions,and offers an effective strategy to design functionalized biomaterials for bone regeneration therapy in diabetic patients.展开更多
The traits of cultured fish must continually be genetically improved to supply high-quality animal protein for human consumption.Economically important fish traits are controlled by multiple gene quantitative trait lo...The traits of cultured fish must continually be genetically improved to supply high-quality animal protein for human consumption.Economically important fish traits are controlled by multiple gene quantitative trait loci(QTL),most of which have minor effects,but a few genes may have major effects useful for molecular breeding.In this review,we chose relevant studies on some of the most intensively cultured fish and concisely summarize progress on identifying and verifying QTLs for such traits as growth,disease and stress resistance and sex in recent decades.The potential applications of these major-effect genes and their associated markers in marker-assisted selection and molecular breeding,as well as future research directions are also discussed.These genetic and genomic analyses will be valuable for elucidating the mechanisms modulating economically important traits and to establish more effective molecular breeding techniques in fish.展开更多
Remote sensing (RS) of land surface temperature (LST) is a very challenging problem at the present development stage of RS science. Tremendous efforts have been devoted to atmosphere correction and temperature emissiv...Remote sensing (RS) of land surface temperature (LST) is a very challenging problem at the present development stage of RS science. Tremendous efforts have been devoted to atmosphere correction and temperature emissivity separation (TES) of new LST product algorithms. However, the mechanism of directionality of thermal emission from land surface remains unknown, and even worse, there are confusions on the definition of the effective emissivity of land surface at the scale of RS pixels. The mechanism of directionality of thermal emission展开更多
The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive mod...The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures （plain, twill 1/3 and satin 8/5） of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy （SEM）. The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions： the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism of fabric composites.展开更多
4.1 Ga old detrital zircon was found by SHRIMP U-Pb dating for quartz schist from Buring County in western Tibet, Southwest China. This is the oldest zircon U-Pb age found in China so far. The detrital zircon is a zir...4.1 Ga old detrital zircon was found by SHRIMP U-Pb dating for quartz schist from Buring County in western Tibet, Southwest China. This is the oldest zircon U-Pb age found in China so far. The detrital zircon is a zircon of magmatic origin because its Th/ U ratios are 0.76 to 0.86. Two dates older than 4.0 Ga were measured only in one grain. U-Pb ages of 35 measured spots in 24 zircons can be subdivided into 6 groups, corresponding to at least 6 episodes of magmatic activity in the target area. The present results provide an important geochronological constraint on the geological evolution of Qinghai-Tibet Plateau.展开更多
Row crops are a kind of typical vegetation canopy between discrete canopy and continuous canopy.Kimes et al.studied the directional thermal radiation of row crops using the geometrical optical model,which simplified r...Row crops are a kind of typical vegetation canopy between discrete canopy and continuous canopy.Kimes et al.studied the directional thermal radiation of row crops using the geometrical optical model,which simplified row structure as'box'and neglected the gap among foliage and did not consider the emissivity effects.In this work we take account of the gaps along illumination and viewing directions and propose a bi-direction gap model on the basis of the idea of gap probability of discrete vegetation canopy introduced by'Li-Strahler'and inter-correlation of continuous vegetation developed by Kuusk.It can be used to explain'hot spot'effects in thermal infrared region.The gap model has been validated by field experiment on winter wheat planted in shape of rows and results show that the gap model is better than Kimes'model in describing the directionality of thermal infrared emission for row crops.展开更多
Hundreds of millions of people around the world are exposed to elevated concentrations of inorganic and organic arsenic compounds, increasing the risk of a wide range of health effects. Studies of the environmental fa...Hundreds of millions of people around the world are exposed to elevated concentrations of inorganic and organic arsenic compounds, increasing the risk of a wide range of health effects. Studies of the environmental fate and human health effects of arsenic require authentic arsenic compounds. We summarize here the synthesis and characterization of more than a dozen methylated and thiolated arsenic compounds that are not commercially available. We discuss the methods of synthesis for the following14 trivalent（Ⅲ） and pentavalent（） arsenic compounds： monomethylarsonous acid（MMA~Ⅲ）, dicysteinylmethyldithioarsenite（MMA~Ⅲ（Cys）_2）, monomethylarsonic acid（MMA~Ⅴ）,monomethylmonothioarsonic acid（MMMTAⅤ） or monothio-MMA~Ⅴ, monomethyldithioarsonic acid（MMDTA~Ⅴ） or dithio-MMA~Ⅴ, monomethyltrithioarsonate（MMTTA~Ⅴ） or trithio-MMA~Ⅴ,dimethylarsinous acid（DMA~Ⅲ）, dimethylarsino-glutathione（DMA~Ⅲ（SG））, dimethylarsinic acid（DMA~Ⅴ）, dimethylmonothioarsinic acid（DMMTA~Ⅴ） or monothio-DMAⅤ, dimethyldithioarsinic acid（DMDTA~Ⅴ） or dithio-DMA~Ⅴ, trimethylarsine oxide（TMAO~Ⅴ）, arsenobetaine（AsB）, and an arsenicin-A model compound. We have reviewed and compared the available methods,synthesized the arsenic compounds in our laboratories, and provided characterization information. On the basis of reaction yield, ease of synthesis and purification of product, safety considerations, and our experience, we recommend a method for the synthesis of each of these arsenic compounds.展开更多
Greenhouse gas emission of carbon dioxide（CO2） is one of the major factors causing global climate change.Urban green space plays a key role in regulating the global carbon cycle and reducing atmospheric CO2.Quantify...Greenhouse gas emission of carbon dioxide（CO2） is one of the major factors causing global climate change.Urban green space plays a key role in regulating the global carbon cycle and reducing atmospheric CO2.Quantifying the carbon stock,distribution and change of urban green space is vital to understanding the role of urban green space in the urban environment.Remote sensing is a valuable and effective tool for monitoring and estimating aboveground carbon（AGC） stock in large areas.In the present study,different remotely-sensed vegetation indices（VIs） were used to develop a regression equation between VI and AGC stock of urban green space,and the best fit model was then used to estimate the AGC stock of urban green space within the beltways of Xi＇an city for the years 2004 and 2010.A map of changes in the spatial distribution patterns of AGC stock was plotted and the possible causes of these changes were analyzed.Results showed that Normalized Difference Vegetation Index（NDVI） correlated moderately well with AGC stock in urban green space.The Difference Vegetation Index（DVI）,Ratio Vegetation Index（RVI）,Soil Adjusted Vegetation Index（SAVI）,Modified Soil Adjusted Vegetation Index（MSAVI） and Renormalized Difference Vegetative Index（RDVI） were lower correlation coefficients than NDVI.The AGC stock in the urban green space of Xi＇an in 2004 and 2010 was 73,843 and 126,621 t,respectively,with an average annual growth of 8,796 t and an average annual growth rate of 11.9%.The carbon densities in 2004 and 2010 were 1.62 and 2.77 t/hm2,respectively.Precipitation was not an important factor to influence the changes of AGC stock in the urban green space of Xi＇an.Policy orientation,major ecological greening projects such as ＂transplanting big trees into the city＂ and the World Horticultural Exposition were found to have an important impact on changes in the spatiotemporal patterns of AGC stock.展开更多
In the dry-sliding process of the woven self-lubricating liner which is used in the self-lubricating spherical plain bearing, the friction heat plays an important role in the tribological performances of the liner. It...In the dry-sliding process of the woven self-lubricating liner which is used in the self-lubricating spherical plain bearing, the friction heat plays an important role in the tribological performances of the liner. It has important value to study on the relationship between tribological performances of the liner and the friction heat. Unforttmately, up to now, published work on this relationship is quite scarce. Therefore, the effect of friction heat on the tribological performances of the liner was investigated in the present work. The tribological behaviors of the liner were evaluated by using the high temperature end surface wear tester. Scanning electron microscopy （SEM） was utilized to examine the morphologies of worn surfaces of the liner and study the failure modes. Differential scanning calorimetry （DSC） measurement and X-ray diffraction （XRD） analysis were performed to study the behaviors of the wear debris. The temperature rise on the worn surface was calculated according to classical models. SEM observation shows that the dominating wear mechanism for the liner is mainly affected by friction shear force, contact pressure and friction heat. Higher fusion heat for the wear debris than that for the pure polytetrafluroethylene （PTFE） indicates that the PTFE is the main portion of the wear debris, and, the PTFE in the wear debris shows a higher crystallisation degree owing to the effects of friction shear force and the friction heat. Combining the calculated temperature rise results with the wear rate of the liner, it can be concluded that the effects of temperature rise o n the tribological performances of the liner become more obvious when the temperature rise exceeds the glass transition temperature （Tg） of the PTFE. The wear resistance of the liner deteriorates dramatically when the temperature rise approaches to the melting point （Ton） of the PTFE. The tribological performances of the liner can be improved when the temperature rise exceeds Tg but is far lower than Ton- The prese展开更多
A model for topographic correction and land surface reflectance estimation for optical remote sensing data in rugged terrian is presented.Considering a directional-directional reflectance that is used for direct solar...A model for topographic correction and land surface reflectance estimation for optical remote sensing data in rugged terrian is presented.Considering a directional-directional reflectance that is used for direct solar irradiance correction and a hemispheric-directional reflectance that is used for atmospheric diffuse irradiance and terrain background reflected irradiance correction respectively,the directional reflectance-based model for topographic effects removing and land surface reflectance calculation is developed by deducing the directional reflectance with topographic effects and using a radiative transfer model.A canopy reflectance simulated by GOMS model and Landsat/TM raw data covering Jiangxi rugged area were taken to validate the performance of the model presented in the paper.The validation results show that the model presented here has a remarkable ability to correct topography and estimate land surface reflectance and also provides a technique method for sequently quantitative remote sensing application in terrain area.展开更多
Foxtail millet(Setaria italica),which was domesticatedfromthewild speciesgreenfoxtail(Setaria viridis),isa richsource of phytonutrientsfor humans.To evaluate how breeding changed themetabolome offoxtail millet grains,...Foxtail millet(Setaria italica),which was domesticatedfromthewild speciesgreenfoxtail(Setaria viridis),isa richsource of phytonutrientsfor humans.To evaluate how breeding changed themetabolome offoxtail millet grains,we generated and analyzed the datasets encompassing the genomes,transcriptomes,metabolomes,and anti-inflammatory indices from 398 foxtail millet accessions.We identified hundreds of common variants that influence numerous secondary metabolites.We observed tremendous differences in natural variations of the metabolites and their underlying genetic architectures between distinct sub-groups of foxtail millet.Furthermore,we found that the selection of the gene alleles associated with yellow grains led to altered profiles of metabolites such as carotenoids and endogenous phytohormones.Using CRiSPR-mediated genome editing wevalidated the function of PHYTOENE SYNTHASE1(PSY1)gene in affecting milletgrain colorand quality.Interestingly,our in vitro cell inflammation assays showed that 83 metabolites in millet grains have anti-inflammatory effects.Taken together,ourmulti-omics study illustrates how the breeding history of foxtail millet has shaped its metabolite profile.The datasets we generated in this study also provide important resources for further understanding how millet grain quality is affected by different metabolites,laying the foundations for future millet genetic research and metabolome-assisted improvement.展开更多
基金supported by the National Key Research and Development Program of China(nos.2016YFC1302204,2017YFC1308600)the National Science Foundation of China(nos.81672502,81872071,81902664)the Natural Science Foundation of Chongqing(no.cstc2019jcyj-zdxmX0033).
文摘Since cancer stem cells(CSCs)were first identified in leukemia in 1994,they have been considered promising therapeutic targets for cancer therapy.These cells have self-renewal capacity and differentiation potential and contribute to multiple tumor malignancies,such as recurrence,metastasis,heterogeneity,multidrug resistance,and radiation resistance.The biological activities of CSCs are regulated by several pluripotent transcription factors,such as OCT4,Sox2,Nanog,KLF4,and MYC.In addition,many intracellular signaling pathways,such as Wnt,NF-κB(nuclear factor-κB),Notch,Hedgehog,JAK-STAT(Janus kinase/signal transducers and activators of transcription),PI3K/AKT/mTOR(phosphoinositide 3-kinase/AKT/mammalian target of rapamycin),TGF(transforming growth factor)/SMAD,and PPAR(peroxisome proliferator-activated receptor),as well as extracellular factors,such as vascular niches,hypoxia,tumor-associated macrophages,cancer-associated fibroblasts,cancer-associated mesenchymal stem cells,extracellular matrix,and exosomes,have been shown to be very important regulators of CSCs.Molecules,vaccines,antibodies,and CAR-T(chimeric antigen receptor T cell)cells have been developed to specifically target CSCs,and some of these factors are already undergoing clinical trials.This review summarizes the characterization and identification of CSCs,depicts major factors and pathways that regulate CSC development,and discusses potential targeted therapy for CSCs.
文摘Chinese mitten crab （Eriocheir sinensis） has higher commercial value as food source than any other species of Eriocheir in China. To evaluate the germplasm resources and characterize the genetic diversity and population structure of the crabs in different water systems, two stocks and two farming populations were assessed with 25 polymorphic microsallite loci available in public GenBank. Basic statistics showed that the average observed heterozygosity （Ho） amongst populations ranged from 0.5789 to 0.6824. However, a remarkable presence of inbreeding and heterozygote deficiencies were observed. To analyze population structure, pairwise FST coefficients explained only -10.3% variability from the subdivision of mitten crab populations, the remaining variability stems from the subdivision within subpopulations. Although the four populations had slight differentiation, different allelic frequencies resulted in distinct population structures. Two stocks and one farming population were clustered together to the phylogenetic branch of Yangtze crab, with an approximate membership of 95%. Whereas, another farming population was clustered singly to the phylogenetic branch of the Liaohe crab, with a membership of 97.1%. The tests for individual admixture showed that Yangtze crab had probably been contaminated with individuals from other water systems. Genetic relationships between populations also supported the conclusion that Yangtze crab and Liaohe crab had different gene pools in spite of the origins of the same species.
基金supported by National Basic Research Program of China (Grant No. 2007CB411502)Key Research Project of the Knowledge In-novation Project of Chinese Academy of Sciences (Grant No. KZCX2-YW-301)+1 种基金Special Trade Project for Commonweal of Water Re-source (Grant No. 200701046)100 Talents Program of China
文摘Using monthly precipitation and temperature data from national meteorological stations, 90 m resolution DEM and a digital vector map of modern glaciers from the Chinese Glacier Inventory, the glacier mass balance and glacier runoff in the Tarim River Basin (TRB), China, were estimated based on a monthly degree-day model for 1961–2006. The results suggest that the modified monthly degree-day model can simulate the long-term changes in glacier mass balance and glacier runoff, which have been confirmed by short-term observation data and other results in literatures. The characteristics and trends of mass balance and glacier runoff variation were analyzed. It was found that the mean annual glacier mass balance during 1961–2006 was ?139.2 mm per year and the cumulative mass balance over the 46 year period was ?6.4 m in the TRB. The glacier mass balance displayed a clear decreasing trend over the entire TRB during 1961–2006. The average annual glacier runoff in the TRB was 144.16×108 m3 for 1961–2006. The results also show that glacier runoff has increased in the last 46 years, especially since the 1990s with 85.7% of the increased river flow being derived from the increased glacier runoff caused by loss of ice mass. Over the entire TRB, glacier runoff accounts for 41.5% of the total river flow during 1961–2006. The impact of glacier runoff on river flow has increased in the TRB as a result of glacier shrinkage.
基金supported by the National Natural Science Foundation of China (30871495)the New Century Project for Excellent Innovative Hu-mans of the Education Ministry of China, the Excellent Youth Foundation Project of Chongqing (2008BA1033)+1 种基金the Special Fund for Basic Scien-tific Research of Central Colleges,Southwest University (XDJK2009B019)China Postdoctoral Science Foundation (20080440608)
文摘Leaf senescence as an active process is essential for plant survival and reproduction.However,premature senility is harmful to agricultural production.In this study,a rice mutant,named as psl3 (presescing leaf 3) isolated from EMS-treated Jinhui 10,displays obvious premature senility features both in morphological and physiological level.Genetic analysis showed that mutant trait was controlled by a single dominant gene (PSL3),which was located on rice chromosome 7 between SSR marker c7sr1 and InDel marker ID10 with an interval of 53.5 kb.The result may be useful for the isolation of the PSL3 gene.
基金ACKNOWLEDGEMENTS This work was supported by grants from the National Natural Science Foundation of China （Grant Nos. 81200762 and 81000162） and R＆D fund of Peking University People＇s Hospital （RBD2013- 16）.
文摘Inflammatory bowel disease （IBD） is an intestinal immune-dysfunctional disease worldwide whose prevalence increasing in Asia including China. It is a chronic disease of the gastrointestinal tract with unknown cause. Exosomes are small vesicles in various body fluids. They have diameters of 40-120 nm, and one of their functions is long-distance transfer of various sub- stances. In this study, we investigated the contents of salivary exosomes in patients with IBD and in healthy controls to explore a new biomarker in patients with IBD. In this study, whole saliva was obtained from patients with IBD （ulcerative colitis （UC）, n = 37; Crohn＇s disease （CD）, n = 11） and apparently healthy individuals （HC, n = 10）. Salivary exosomes were extracted from samples, and the proteins within the exosomes were iden- tified by liquid chromatograph-mass spectrometer （LC- MS/MS）. The results showed that more than 2000 proteins were detected in salivary exosomes from patients with IBD. Through gene ontology analysis, we found that proteasome subunit alpha type 7 （PSMA7） showed especially marked differences between patients with IBD and the healthy controls, in that its expression level was much higher in the CD and UC groups. This exosomal protein is related to proteasome activity and inflamma- tory responses. So we conclude that in this research,salivary exosomal PSMA7 was present at high levels in salivary exosomes from subjects with IBD. It can be a very promising biomarker to release the patients from the pain of colonoscopy.
基金This study was supported by the Scientific Research and Technological Development Program Project of Guangxi Province （10124001A-32）, the Young Science Foundation of Guangxi Medical University （GXMUSF201206） and the Innovation Project of Guangxi Graduate Education （YCBZ2013014）.
文摘The pro-inflammation factor high-mobility group box protein 1 （HMGB1） has been implicated in the pathogenesis of asthma. In this study, we used a murine model of chronic asthma to evaluate the effects of HMGB 1 on airway remodeling. Female BALB/c mice were randomly divided into four groups： control, ovalbumin （OVA） asthmatic, OVA＋ isotype antibody and OVA＋anti-HMGB 1 antibody. Anti-HMGB 1 antibody therapy was started on day 21 and was administered three times per week for 6 weeks before intranasal challenge with OVA. In this mouse model, HMGB1 expression is significantly elevated. The anti-HMGB1 antibody group exhibited decreased levels of immunoglobulin E （IgE） and inflammatory mediators and reduced inflammatory cell accumulation, airway hyperresponsiveness （AHR）, mucus synthesis, smooth muscle thickness and lung collagen content compared with the OVA groups. Treatment with HMGB1 increased proliferation, migration, collagen secretion and a-smooth muscle actin （SMA） expression in MRC-5 ceils. Treatment with the HMGB1/IL-1β complex significantly increased the expression and secretion of transforming growth factor （TGF-βl）, matrix metalloproteinase （MMP）-9 and vascular endothelial growth factor （VEGF）. Altogether, these results suggest that blocking HMGB1 activity may reverse airway remodeling by suppressing airway inflammation and modulating lung fibroblast phenotype and activation.
基金This work was supported by the National Key R&D Program of China(2018YFC1105303/04)National Natural Science Foundation of China(Nos.51772006,31670993,51973004,81991505,82022016)+3 种基金Beijing Municipal Science&Technology Commission Projects(Z181100002018001)Peking University Medicine Fund(Nos.PKU2020LCXQ009,BMU2020PYB029)Natural Science Foundation of Hunan Province(2019JJ50779)Health and Family Planning Commission of Hunan Province(20180246).
文摘Macrophage-mediated inflammation compromises bone repair in diabetic patients.Electrical signaling cues are known to regulate macrophage functions.However,the biological effects of electrical microenvironment from charged biomaterials on the immune response for regulating osteogenesis under diabetic conditions remain to be elucidated.Herein the endogeneous electrical microenvironment of native bone tissue was recapitulated by fabricating a ferroelectric BaTiO_(3)/poly(vinylidene fluoridetrifluoroethylene)(BTO/P(VDF-TrFE))nanocomposite membrane.In vitro,the polarized BaTiO_(3)/poly(vinylidene fluoridetrifluoroethylene)(BTO/P(VDF-TrFE))nanocomposite membranes inhibited high glucose-induced M1-type inflammation,by effecting changes in cell morphology,M1 marker expression and pro-inflammatory cytokine secretion in macrophages.This led to enhanced osteogenic differentiation of human bone marrow mesenchymal stem cells(BM-MSCs).In vivo,the biomimetic electrical microenvironment recapitulated by the polarized nanocomposite membranes switched macrophage phenotype from the pro-inflammatory(M1)into the pro-healing(M2)phenotype,which in turn enhanced bone regeneration in rats with type 2 diabetes mellitus.Mechanistic studies revealed that the biomimetic electrical microenvironment attenuated pro-inflammatory M1 macrophage polarization under hyperglycemic conditions by suppressing expression of AKT2 and IRF5 within the PI3K-AKT signaling pathway,thereby inducing favorable osteo-immunomodulatory effects.Our study thus provides fundamental insights into the biological effects of restoring the electrical microenvironment conducive for osteogenesis under DM conditions,and offers an effective strategy to design functionalized biomaterials for bone regeneration therapy in diabetic patients.
基金supported by the National Basic Research Program of China(2010CB126305)
文摘The traits of cultured fish must continually be genetically improved to supply high-quality animal protein for human consumption.Economically important fish traits are controlled by multiple gene quantitative trait loci(QTL),most of which have minor effects,but a few genes may have major effects useful for molecular breeding.In this review,we chose relevant studies on some of the most intensively cultured fish and concisely summarize progress on identifying and verifying QTLs for such traits as growth,disease and stress resistance and sex in recent decades.The potential applications of these major-effect genes and their associated markers in marker-assisted selection and molecular breeding,as well as future research directions are also discussed.These genetic and genomic analyses will be valuable for elucidating the mechanisms modulating economically important traits and to establish more effective molecular breeding techniques in fish.
文摘Remote sensing (RS) of land surface temperature (LST) is a very challenging problem at the present development stage of RS science. Tremendous efforts have been devoted to atmosphere correction and temperature emissivity separation (TES) of new LST product algorithms. However, the mechanism of directionality of thermal emission from land surface remains unknown, and even worse, there are confusions on the definition of the effective emissivity of land surface at the scale of RS pixels. The mechanism of directionality of thermal emission
基金supported by National Defense Foundation of China
文摘The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures （plain, twill 1/3 and satin 8/5） of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy （SEM）. The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions： the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism of fabric composites.
基金Supported by National 973 Project (Grant No. 2002CB412600) the National Natural Science Foundation of China (Grant No. 40472058)
文摘4.1 Ga old detrital zircon was found by SHRIMP U-Pb dating for quartz schist from Buring County in western Tibet, Southwest China. This is the oldest zircon U-Pb age found in China so far. The detrital zircon is a zircon of magmatic origin because its Th/ U ratios are 0.76 to 0.86. Two dates older than 4.0 Ga were measured only in one grain. U-Pb ages of 35 measured spots in 24 zircons can be subdivided into 6 groups, corresponding to at least 6 episodes of magmatic activity in the target area. The present results provide an important geochronological constraint on the geological evolution of Qinghai-Tibet Plateau.
基金This work was supported by the Special Funds for Major State Basic Research Project(Grant No.G2000077900).
文摘Row crops are a kind of typical vegetation canopy between discrete canopy and continuous canopy.Kimes et al.studied the directional thermal radiation of row crops using the geometrical optical model,which simplified row structure as'box'and neglected the gap among foliage and did not consider the emissivity effects.In this work we take account of the gaps along illumination and viewing directions and propose a bi-direction gap model on the basis of the idea of gap probability of discrete vegetation canopy introduced by'Li-Strahler'and inter-correlation of continuous vegetation developed by Kuusk.It can be used to explain'hot spot'effects in thermal infrared region.The gap model has been validated by field experiment on winter wheat planted in shape of rows and results show that the gap model is better than Kimes'model in describing the directionality of thermal infrared emission for row crops.
基金supported by Alberta Health, Alberta Innovates, the Canada Research Chairs Programthe Canadian Institutes of Health Research (CIHR)the Natural Sciences and Engineering Research Council (NSERC) of Canada
文摘Hundreds of millions of people around the world are exposed to elevated concentrations of inorganic and organic arsenic compounds, increasing the risk of a wide range of health effects. Studies of the environmental fate and human health effects of arsenic require authentic arsenic compounds. We summarize here the synthesis and characterization of more than a dozen methylated and thiolated arsenic compounds that are not commercially available. We discuss the methods of synthesis for the following14 trivalent（Ⅲ） and pentavalent（） arsenic compounds： monomethylarsonous acid（MMA~Ⅲ）, dicysteinylmethyldithioarsenite（MMA~Ⅲ（Cys）_2）, monomethylarsonic acid（MMA~Ⅴ）,monomethylmonothioarsonic acid（MMMTAⅤ） or monothio-MMA~Ⅴ, monomethyldithioarsonic acid（MMDTA~Ⅴ） or dithio-MMA~Ⅴ, monomethyltrithioarsonate（MMTTA~Ⅴ） or trithio-MMA~Ⅴ,dimethylarsinous acid（DMA~Ⅲ）, dimethylarsino-glutathione（DMA~Ⅲ（SG））, dimethylarsinic acid（DMA~Ⅴ）, dimethylmonothioarsinic acid（DMMTA~Ⅴ） or monothio-DMAⅤ, dimethyldithioarsinic acid（DMDTA~Ⅴ） or dithio-DMA~Ⅴ, trimethylarsine oxide（TMAO~Ⅴ）, arsenobetaine（AsB）, and an arsenicin-A model compound. We have reviewed and compared the available methods,synthesized the arsenic compounds in our laboratories, and provided characterization information. On the basis of reaction yield, ease of synthesis and purification of product, safety considerations, and our experience, we recommend a method for the synthesis of each of these arsenic compounds.
基金supported by the Forestry Research Foundation for the Public Service Industry of China (200904004)
文摘Greenhouse gas emission of carbon dioxide（CO2） is one of the major factors causing global climate change.Urban green space plays a key role in regulating the global carbon cycle and reducing atmospheric CO2.Quantifying the carbon stock,distribution and change of urban green space is vital to understanding the role of urban green space in the urban environment.Remote sensing is a valuable and effective tool for monitoring and estimating aboveground carbon（AGC） stock in large areas.In the present study,different remotely-sensed vegetation indices（VIs） were used to develop a regression equation between VI and AGC stock of urban green space,and the best fit model was then used to estimate the AGC stock of urban green space within the beltways of Xi＇an city for the years 2004 and 2010.A map of changes in the spatial distribution patterns of AGC stock was plotted and the possible causes of these changes were analyzed.Results showed that Normalized Difference Vegetation Index（NDVI） correlated moderately well with AGC stock in urban green space.The Difference Vegetation Index（DVI）,Ratio Vegetation Index（RVI）,Soil Adjusted Vegetation Index（SAVI）,Modified Soil Adjusted Vegetation Index（MSAVI） and Renormalized Difference Vegetative Index（RDVI） were lower correlation coefficients than NDVI.The AGC stock in the urban green space of Xi＇an in 2004 and 2010 was 73,843 and 126,621 t,respectively,with an average annual growth of 8,796 t and an average annual growth rate of 11.9%.The carbon densities in 2004 and 2010 were 1.62 and 2.77 t/hm2,respectively.Precipitation was not an important factor to influence the changes of AGC stock in the urban green space of Xi＇an.Policy orientation,major ecological greening projects such as ＂transplanting big trees into the city＂ and the World Horticultural Exposition were found to have an important impact on changes in the spatiotemporal patterns of AGC stock.
文摘In the dry-sliding process of the woven self-lubricating liner which is used in the self-lubricating spherical plain bearing, the friction heat plays an important role in the tribological performances of the liner. It has important value to study on the relationship between tribological performances of the liner and the friction heat. Unforttmately, up to now, published work on this relationship is quite scarce. Therefore, the effect of friction heat on the tribological performances of the liner was investigated in the present work. The tribological behaviors of the liner were evaluated by using the high temperature end surface wear tester. Scanning electron microscopy （SEM） was utilized to examine the morphologies of worn surfaces of the liner and study the failure modes. Differential scanning calorimetry （DSC） measurement and X-ray diffraction （XRD） analysis were performed to study the behaviors of the wear debris. The temperature rise on the worn surface was calculated according to classical models. SEM observation shows that the dominating wear mechanism for the liner is mainly affected by friction shear force, contact pressure and friction heat. Higher fusion heat for the wear debris than that for the pure polytetrafluroethylene （PTFE） indicates that the PTFE is the main portion of the wear debris, and, the PTFE in the wear debris shows a higher crystallisation degree owing to the effects of friction shear force and the friction heat. Combining the calculated temperature rise results with the wear rate of the liner, it can be concluded that the effects of temperature rise o n the tribological performances of the liner become more obvious when the temperature rise exceeds the glass transition temperature （Tg） of the PTFE. The wear resistance of the liner deteriorates dramatically when the temperature rise approaches to the melting point （Ton） of the PTFE. The tribological performances of the liner can be improved when the temperature rise exceeds Tg but is far lower than Ton- The prese
基金the National Natural Science Foundation of China (Grant No.40730525)Knowledge Innovation Engineering Project of Chinese Academy of Sciences (Grant No.KZCX2-YW-313)China's Special Funds for Major State Basic Research Project (Grant No.2007CB714401)
文摘A model for topographic correction and land surface reflectance estimation for optical remote sensing data in rugged terrian is presented.Considering a directional-directional reflectance that is used for direct solar irradiance correction and a hemispheric-directional reflectance that is used for atmospheric diffuse irradiance and terrain background reflected irradiance correction respectively,the directional reflectance-based model for topographic effects removing and land surface reflectance calculation is developed by deducing the directional reflectance with topographic effects and using a radiative transfer model.A canopy reflectance simulated by GOMS model and Landsat/TM raw data covering Jiangxi rugged area were taken to validate the performance of the model presented in the paper.The validation results show that the model presented here has a remarkable ability to correct topography and estimate land surface reflectance and also provides a technique method for sequently quantitative remote sensing application in terrain area.
基金This workwas supportedby the National KeyR&DProgramof China(2019YFD1000700 and 2019YFD1000702)the JointFunds of theNational Natural Science Foundation of China(U21A20216)+4 种基金the Key R&D Program of Shanxi Province(201903D11006)theMajor Special Science and Technology Projects in Shanxi Province(202101140601027)the National Natural Science Foundation of China(32001608 and 31771810)the Scientific and Technological Innovation Programs of Shanxi Agricultural University(2017YJ27)Lundbeck Foundation(R346-2020-1546)grants.S.P.also acknowledges the financial aid of an ARC Discovery grant(DP19001941),Villum Investigator(25915),DNRF Chair(DNRF155),Novo Nordisk Laureate(NNF190C0056076),NovoNordisk Emerging Investigator(NNF20OC0060564).
文摘Foxtail millet(Setaria italica),which was domesticatedfromthewild speciesgreenfoxtail(Setaria viridis),isa richsource of phytonutrientsfor humans.To evaluate how breeding changed themetabolome offoxtail millet grains,we generated and analyzed the datasets encompassing the genomes,transcriptomes,metabolomes,and anti-inflammatory indices from 398 foxtail millet accessions.We identified hundreds of common variants that influence numerous secondary metabolites.We observed tremendous differences in natural variations of the metabolites and their underlying genetic architectures between distinct sub-groups of foxtail millet.Furthermore,we found that the selection of the gene alleles associated with yellow grains led to altered profiles of metabolites such as carotenoids and endogenous phytohormones.Using CRiSPR-mediated genome editing wevalidated the function of PHYTOENE SYNTHASE1(PSY1)gene in affecting milletgrain colorand quality.Interestingly,our in vitro cell inflammation assays showed that 83 metabolites in millet grains have anti-inflammatory effects.Taken together,ourmulti-omics study illustrates how the breeding history of foxtail millet has shaped its metabolite profile.The datasets we generated in this study also provide important resources for further understanding how millet grain quality is affected by different metabolites,laying the foundations for future millet genetic research and metabolome-assisted improvement.
