维普中文期刊产品整合服务
786篇 您的检索式:作者名="Yujun"
    题名 作者 年代 出处 被引量
1A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)显示文摘The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs. We report the complete genome sequence and comparative analysis of an isolate (BJ01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 2 ORFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS- associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to beinvolved in the immunoreactions between the virus and its host. Two amino acid changes have been detected in the Mprotein, which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides noevidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of otherpossible SARS-related pathogen(s).QIN E'de ZHU Qingyu YU Man FAN Baochang CHANG Guohui SI Bingyin YANG Bao PENG Wenming JIANG Tao LIU Bohua DENG Yongqiang LIU Hong ZHANG Yu WANG Cui LI Yuquan GAN Yonghua LI Xiaoyu L Fushuang TAN Gang CAO Wuchun, YANG Ruifu Institute of Microbiology and Epidemiology, Chinese Academy of Military Medical Sciences, Beijing 100071, China WANG Jian, LI Wei, XU Zuyuan, LI Yan, WU Qingfa, LIN Wei, CHEN Weijun, TANG Lin, DENG Yajun, HAN Yujun, LI Changfeng, LEI Meng, LI Guoqing, LI Wenjie, L Hong, SHI Jianping, TONG Zongzhong, ZHANG Feng, LI Songgang, LIU Bin, LIU Siqi, DONG Wei, WANG Jun, Gane K-S Wong, YU Jun & YANG Huanming* Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300 National Center for Genome Information, Beijing 101300, China 2003Chinese Science Bulletin2003,48,10:121
2aunalysis of the Genome Sequence of the Medicinal Plant Salvia miltiorrhiza显示文摘Haibin Xu Jingyuan Song Hongmei Luo Yujun Zhang Qiushi Li Yingjie Zhu Jiang Xu Ying Li Chi Song Bo Wang Wei Sun Guoan Shen Xin Zhang Jun Qian Aijia Ji Zhichao Xu Xiang Luo Liu He Chuyuan Li Chao Sun Haixia Yah Guanghong Cui Xiwen Li Xian 'en Li Jianhe Wei Juyan Liu Yitao Wang Alice Hayward David Nelson Zemin Ning Reuben J. Peters Xiaoquan Qi Shilin Chen 2016Molecular Plant2016,9,6:70
3A scientometric review of biochar research in the past 20 years(1998-2018)显示文摘Biochar is the carbon-rich product obtained from the thermochemical conversion of biomass under oxygen-limited conditions.Biochar has attained extensive attention due to its agronomical and environmental benefits in agro-ecosystems.This work adopts the scientometric analysis method to assess the development trends of biochar research based on the literature data retrieved from the Web of Science over the period of 1998-2018.By analysing the basic characteristics of 6934 publications,we found that the number of publications grew rapidly since 2010.Based on a keyword analysis,it is concluded that scholars have had a fundamental recognition of biochar and preliminarily found that biochar application had agronomic and environmental benefits during the period of 1998-2010.The clustering results of keywords in documents published during 2011-2015 showed that the main research hotspots were“biochar production”,“biochar and global climate change”,“soil quality and plant growth”,“organic pollutants removal”,and“heavy metals immobilization”.While in 2016-2018,beside these five main research hotspots,“biochar and composting”topic had also received greater attention,indicating that biochar utilization in organic solid waste composting is the current research hotspot.Moreover,updated reactors(e.g.,microwave reactor,fixed-bed reactor,screw-feeding reactor,bubbling fluidized bed reactor,etc.)or technologies(e.g.,solar pyrolysis,Thermo-Catalytic Reforming process,liquefaction technology,etc.)applied for efficient energy production and modified biochar for environmental remediation have been extensively studied recently.The findings may help the new researchers to seize the research frontier in the biochar field.Ping Wu Syed Tahir Ata-Ul-Karim Bhupinder Pal Singh Hailong Wang Tongliang Wu Cun Liu Guodong Fang Dongmei Zhou Yujun Wang Wenfu Chen 2019Biochar2019,1,1:36
4Sediment pollution and its effect on fish through food chain in the Yangtze River显示文摘Suspended sediment adsorbs pollutants from flowing water in rivers and deposits onto the bed. However, the pollutants accumulated in the river bed sediment may affect the bio-community through food chain for a long period of time. To study the problem the concentration of heavy metals (Cr, Cd, Hg, Cu, Fe, Zn, Pb and As) in water, sediment, and fish/invertebrate were investigated in the middle and lower reaches of the Yangtze River during 2006-2007. The concentrations of heavy metals were 100-10,000 times higher in the sediment than in the water. Benthic invertebrates had relatively high concentrations of heavy metals in their tissues due to their proximity to contaminated sediments. Benthic invertivore fish had moderately high concentrations of heavy metals whereas phytoplanktivore fish, such as the silver carp, accumulated the lowest concentration of heavy metals. The concentrations of Cu, Zn, and Fe were higher than Hg, Pb, Cd, Cr, and As in the tissue samples. The concentration of heavy metals was lower in the river sediments than in the lake sediments. Conversely, the concentration of heavy metals was higher in river water than in lake water. While a pollution event into a water body is often transitory, the effects of the pollutants may be long-lived due to their tendency to be absorbed in the sediments and then released into the food chain. The heavy metals were concentrated in the following order: bottom material > demersal fish and benthic fauna > middle-lower layer fish > upper-middle layer fish > water.Yujun YI Zhaoyin WANG Kang ZHANG Guoan YU Xuehua DUAN 2008International Journal of Sediment Research2008,23,4:34
5Overweight, obesity, and screen-time viewing among Chinese school-aged children: National prevalence estimates from the 2016 Physical Activity and Fitness in China—The Youth Study显示文摘Purpose: This study presents the most recent estimates of prevalence of overweight, obesity, and screen-time viewing among Chinese school-aged children. Demographic differences in these estimates between sexes and resident locales were also examined.Methods: Cross-sectional analyses of 116,615 Chinese school children 9 to 17 years of age who participated in the 2016 Physical Activity and Fitness in China—The Youth Study project. Outcomes were the prevalence of children's overweight(85 th ≤ body mass index(BMI) < 95 th percentile) and obesity(BMI ≥95 th percentile)(defined by the Working Group on Obesity in China) and not meeting screen-time viewing recommendations('not meeting' was defined as more than 2 h per day of viewing activities after school). Analyses were conducted on the whole sample and by school grade cohorts(primary, junior middle, and junior high schools), sex, and residence locales(urban, rural).Results: Overall, 14.4%(95% confidence interval(CI): 13.8%–15.0%) of children and adolescents were overweight, 11.9%(95%CI: 11.0%–13.0%) were obese, and 36.8%(95%CI: 34.7%–38.9%) did not meet screen-time viewing recommendations. Across the 3-grade cohorts, boys were more likely to be obese than girls, and primary and junior middle school children living in urban areas were more likely to be obese than those living in rural areas. Primary and junior middle school boys were less likely to meet screen-time recommendations than girls, and junior high school children living in urban areas were less likely to meet screen-time recommendations than school children of the same grades living in rural areas.Conclusion: In 2016, the prevalence of obesity among Chinese school children was about 12%, and about 37% of them did not meet screen-time viewing recommendations. The prevalence of obesity and sedentary behavior was generally higher among boys than among girls, and it was higher for children living in urban areas than for those living in rural areas.Yujun Cai Xihe Zhu Xueping Wu 2017Journal of Sport and Health Science2017,6,4:30
6Micro-mechanical analysis of dynamic processes of nanomanipulation显示文摘In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture.HU Jie, ZHANG Yujun, LI Peng, WANG Hui, HUANG Lan & HU YuanzhongState Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China Department of Physics, Tsinghua University, Beijing 100084, China College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China 2004Science China(Physics,Mechanics & Astronomy)2004,47,z1:28
7Thermodynamics and kinetics of phase transformation in rare earth–magnesium alloys:A critical review显示文摘Magnesium and its alloys are significant superior metallic materials for structural components in automobile and aerospace industries due to their excellent physicomechanical properties.The Mg–rare earth(RE)systems have attracted great interests because RE additions can improve both the deformability and the strength of Mg alloys through solid solution strengthening and precipitation hardening mechanisms.This paper focuses on the interface stability,together with thermodynamics and kinetics of nucleation and growth of the key phases and matrix phases in Mg–RE alloys.In this paper,the theory and recent advances on Mg–RE alloys,especially for the interface stability,thermodynamics and kinetics of nucleation and growth of the key phases and matrix phases,together with their relationships with micro-structures,and macroscopic properties,are reviewed.By combining the thermodynamics/kinetics integrated simulations with various advanced experimental techniques,“reverse”design of Mg–RE alloys starting from the target service performance is put forward as a kind of scientific paradigm with rational design.Qun Luo Yanlin Guo Bin Liu Yujun Feng Jieyu Zhang Qian Li Kuochih Chou 2020Journal of Materials Science & Technology2020,44,9:26
8Recent advances of microneedles for biomedical applications: drug delivery and beyond显示文摘The microneedle(MN), a highly efficient and versatile device, has attracted extensive scientific and industrial interests in the past decades due to prominent properties including painless penetration, low cost, excellent therapeutic efficacy, and relative safety. The robust microneedle enabling transdermal delivery has a paramount potential to create advanced functional devices with superior nature for biomedical applications. In this review, a great effort has been made to summarize the advance of microneedles including their materials and latest fabrication method, such as three-dimensional printing(3DP). Importantly, a variety of representative biomedical applications of microneedles such as disease treatment, immunobiological administration, disease diagnosis and cosmetic field, are highlighted in detail. At last, conclusions and future perspectives for development of advanced microneedles in biomedical fields have been discussed systematically. Taken together, as an emerging tool, microneedles have showed profound promise for biomedical applications.Jian Yang Xinli Liu Yunzhi Fu Yujun Song 2019Acta Pharmaceutica Sinica B2019,9,3:21
9Temporal variation of soil carbon stock and its controlling factors over the last two decades on the southern Song-nen Plain,Heilongjiang Province显示文摘对全球气候变化的当前的背景,在土壤碳水池和它的控制因素的变化的学习可以在温室气体的缓解或改进帮助土壤角色的评估。这份报纸在 Heilongjiang 省在南部的 Song-nen 平原在土壤碳水池和他们的控制因素学习空间、时间的变化,用在二个不同时期由上收集的土壤数据在 20052007 的多种用途的地区性的 Geochemical 调查,和另外一个玷污在 19821990 进行的调查。学习区域是 1479 t/km2 并且在过去的 20 年里的碳来源,从直到 2005 的 1980 年代,从土壤的实际的碳排放是 0.12 Gt。温度,被发现了线性地被相关玷污器官的碳,是控制器官的碳满足的土壤的主导的 climatologic 因素。我们的学习在器官的碳由升起的温度引起了的土壤的潜在的损失是的相关区域和时间时期显示出那 0.10 Gt ,源于陆地使用变化的潜在的土壤碳排放是 0.09 Gt ,并且温暖和陆地使用变化引起的土壤碳( 0.19 Gt )的联合潜在的损失比得上石块燃料燃烧( 0.21 Gt )的。由于在土壤碳水池变化的时间延期,仍然在温暖和以后将逐渐地被释放的陆地使用变化引起的潜在的排放有 0.07 Gt。Xueqi Xia Zhongfang Yang Yan Liao Yujun Cui Yansheng Li 2010Geoscience Frontiers2010,1,1:19
10RGF1 INSENSITIVE 1 to 5, a group of LRR receptor-like kinases, are essential for the perception of root meristem growth factor I in Arabidopsis thaliana显示文摘RGF1,分泌的肽荷尔蒙,戏在 Arabidopsis 在根分裂组织开发给角色调音。以前的研究显示功能的 RGF1 需要是在由 tyrosylprotein sulfotransferase 的酷氨酸残余的 sulfated 并且 RGF1 主要经由二个下游的抄写因素调整根分裂组织活动,过多 1 (PLT1 ) 并且 PLT2。然而,细胞外的 RGF1 怎么被一个植物房间察觉,是不清楚的。用基因途径,我们发现了充满白氨酸的重复的 clade 像受体的 kinases,指定了为 RGF1 感觉迟钝 1 (RGI1 ) 到 RGI5,用作 RGF1 的受体。二独立 rgi1 rgi2 rgi3 rgi4 rgi5 五倍的异种与分裂组织的一种小尺寸显示一致的短主要的根显型。四倍的异种显示出的 rgi1 rgi2 rgi3 rgi4 到 RGF1 的显著地减少的敏感,和五倍的异种对 RGF1 完全感觉迟钝。PLT1 和 PLT2 的表示在五倍的异种是几乎无法发现的。一个 RGI2 倡导者极大地在五倍的异种驾驶的 PLT2 的宫外的表示救了它的根分裂组织缺点。RGI 之一, RGI1,随后详细生物化学地被分析。在 vitro 点弄污和下拉,分析显示 RGI1 能身体上与 RGF1 交往。RGF1 的外长的申请能快速并且同时导致 RGI1 的 phosphorylation 和 ubiquitination,显示 RGI1 能察觉并且 transduce RGF1 肽信号。然而,激活的 RGI1 多半很快被翻。这些结果表明那 RGI,充当 RGF1 的受体,在在 Arabidopsis thaliana 的 RGF1-PLT-mediated 根分裂组织开发的戏必需品角色。Yang Ou Xiaoting Lu Quaner Zi Qingqing Xun Jingjie Zhang Yujun Wu Hongyong Shi Zhuoyun Wei Baolin Zhao Xiaoyue Zhang Kai He Xiaoping Gou Chuanyou Li Jia Li 2016Cell Research2016,26,6:18
11Combined bone marrow stromal cells and oxiracetam treatments ameliorates acute cerebral ischemia/reperfusion injury through TRPC6显示文摘Ischemic stroke has become one of the leading causes of deaths and disabilities all over the world.In this study,we investigated the therapeutic effects of combined bone marrow stromal cells(BMSCs)and oxiracetam treatments on acute cerebral ischemia/reperfusion(I/R)injury.A rat model of middle cerebral artery occlusion(MCAO)followed by complete reperfusion,as well as a cortex neuron oxygen-glucose deprivation(OGD)model was established.When compared with BMSCs or oxiracetam monotherapy,combination therapy significantly improved functional restoration with decreased infarct volume in observed ischemic brain.We propose that it may occur through the transient receptor potential canonical(TRPC)6 neuron survival pathway.The increased expression of TRPC6 along with the reduction of neuronal cell death in the OGD cortex neurons and combination therapy group indicated that the TRPC6 neuron survival pathway plays an important role in the combined BMSCs and oxiracetam treatments.We further tested the activity of the calpain proteolytic system,and the results suggested that oxiracetam could protect the integrity of TRPC6 neuron survival pathway by inhibiting TRPC6 degradation.The protein levels of phospho-cAMP response element binding protein(p-CREB)were tested.It was found that BMSCs play a role in the activation of the TRPC6 pathway.Our study suggests that the TRPC6 neuron survival pathway plays a significant role in the protective effect of combined BMSCs and oxiracetam treatments on acute cerebral I/R injury.Combined therapy could inhibit the abnormal degradation of TRPC6 via decreasing the activity of calpain and increasing the activation of TRPC6 neuron survival pathway.Jing Wang Ruohan Sun Zhenzhu Li Yujun Pan 2019Acta Biochimica et Biophysica Sinica2019,51,8:17
12Experimental investigation of the influence of electric field on frost layer growth under natural convection condition显示文摘直接电流(DC ) 的影响一个冷垂直盘子上的霜的厚度和团上的电场被调查。生长有或没有电场的存在被拿,并且结果的霜层的相片证明电走在霜厚度上有强烈影响。霜厚度和霜质量上的冷板温度和周围的温度的影响也与电场在自然传送对流条件下面被调查。试验性的结果证明冷板温度在霜层厚度,而是它对霜质量的影响上有很强壮的效果是次要的;对霜团的影响或周围的温度在霜厚度上是比那更明显的。ZHANG Xinhua, LIU Zhongliang, WANG Jieteng, GOU Yujun, MENG Sheng and MA Chongfang Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, Beijing University of Technology, Beijing 100022, China 2006Progress in Natural Science:Materials International2006,16,4:16
13A carbon-oxygen-bridged ladder-type building block for efficient donor and acceptor materials used in organic solar cells显示文摘A carbon-oxygen-bridged ladder-type donor unit(CO5) was invented and prepared via an ‘‘intramolecular demethanolization cyclization' approach. Its single crystal structure indicates enhanced planarity compared with the carbon-bridged analogue indacenodithiophene(IDT). Owing to the stronger electron-donating capability of CO5 than IDT, CO5-based donor and acceptor materials show narrower bandgaps. A donor-acceptor(D-A) copolymer donor(PCO5TPD) and an A-D-A nonfullerene acceptor(CO5IC) demonstrated higher performance than IDT-based counterparts, PIDTTPD and IDTIC, respectively. The better performance of CO5-based materials results from their stronger light-harvesting capability and higher charge-carrier mobilities.Zuo Xiao Fan Liu Xinjian Geng Jianqi Zhang Shizhe Wang Yujun Xie Zhen Li Huai Yang Yongbo Yuan Liming Ding 2017Science Bulletin2017,62,19:16
14Bone marrow stromal cells as a therapeutic treatment for ischemic stroke显示文摘Cerebral ischemia remains the most frequent cause of death and quality-of-life impairments due to neurological deficits, and accounts for the majority of total healthcare costs. However, treatments for cerebral ischemia are limited. Over the last decade, bone marrow stromal cell(BMSC) therapy has emerged as a particularly appealing option, as it is possible to help patients even when initiated days or even weeks after the ischemic insult. BMSCs are a class of multipotent, self-renewing cells that give rise to differentiated progeny when implanted into appropriate tissues. Therapeutic effects of BMSC treatment for ischemic stroke, including sensory and motor recovery, have been reported in pre-clinical studies and clinical trials. In this article, we review the recent progress in BMSC-based therapy for ischemic stroke, focusing on the route of delivery and pre-processing of BMSCs. Selecting an optimal delivery route is of particular importance. The ideal approach, as well as the least risky, for translational applications still requires further identification. Appropriate preprocessing of BMSCs or combination therapy has the benefit of achieving the maximum possible restoration. Further pre-clinical studies are required to determine the time-window for transplantation and the appropriate dosage of cells.Zizhen Yang Lei Zhu Fangqin Li Jing Wang Huan Wan Yujun Pan 2014Neuroscience Bulletin2014,30,3:16
15Controllable preparation of particles with microfluidics显示文摘This paper reviews recent development and achievements in controllable preparation of nanoparticles, micron spherical and non-spherical particles, using microfluidics. A variety of synthesis strategies are presented and compared, including single-phase and multiphase microflows. The main structures of microfluidic devices and the fundamental principles of microflows for particle preparation are summarized and identifled. The controllability of particle size, size distribution, crystal structure, morphology, physical and chemical properties, is examined in terms of the special features of microfluidic reactors. An outlook on opinions and predictions concerning the future development of powder technology with microfluidics is specially provided.Guangsheng Luo Le Du Yujun Wang Yangcheng Lu Jianhong Xu 2011Particuology2011,9,6:15
16Visualizing the emerging trends of biochar research and applications in 2019:a scientometric analysis and review显示文摘Biochar,derived from thermal pyrolysis of biomass,has been regarded as a low-cost,sustainable and beneficial material and widely applied in agriculture,environment and energy during the last two decades.To elucidate the research status timely and future trends in biochar field,CiteSpace is used to systematically analyze the related literature retrieved from the Web of Science core collection in 2019.Based on the keywords clustering analysis,it was found that“biochar production”,“organic pollutants removal”,“heavy metals immobilization”,“bioremediation”were the main hotspots in research covering biochar.“Bioremediation”is an emerging topic and deserves extensive attention due to its highly effective and environmentally friendly treatment of pollutants.Improving the phytoremediation effect,immobilizing functional microorganisms on biochar,and using microorganisms as raw materials to produce biochar were the common methods of biochar-assisted bioremediation.While studies focused on“soil quality and plant growth”and“biochar and global climate change”decreased,investigations concentrated in the toxicity of biochar to soil biota and ruminants are sustainably growing.Research on direct and catalytic thermal pyrolysis of green waste(mainly microalgae)for biofuels(bio-oil,biodiesel,syngas,etc.)and biochar production is increasing.Converting municipal wastes(e.g.,sewage sludge,fallen leaves)into biochar through pyrolysis was a suitable treatment for municipal waste and became a popular topic in recent time.Moreover,the biochar produced from these municipal wastes exhibited excellent performance in the removal of pollutants from wastewater and soil.This review may help to identify future directions in biochar research and applications.Ping Wu Zeyu Wang Hailong Wang Nanthi S.Bolan Yujun Wang Wenfu Chen 2020Biochar2020,2,2:14
17Direct reprogramming of human fibroblasts into dopaminergic neuron-like cells显示文摘外长的 dopaminergic 神经原(DA 神经原) 的移植是为治疗 Parkinson 的疾病(PD ) 的一条有希望的途径。然而,主要跌倒块是施主 DA 神经原的可靠来源的缺乏。这里,我们证明五 transcriptional 因素 Mash1, Ngn2, Sox2, Nurr1,和 Pitx3 的联合直接并且有效地装改编人成纤维细胞进 DA 像神经原的房间。为为 DA 神经原的各种各样的标记积极的染色的 reprogrammed 房间。他们也显示出典型 DA 举起和生产性质。而且,他们展出了 DA 神经原特定的 electrophysiological 侧面。最后,他们在一个老鼠 PD 模型提供了征兆的地势。因此,我们的直接 reprogrammed DA 像神经原的房间是为 PD 的房间代替治疗的有希望的来源。Xinjian Liu Fang Li Elizabeth A Stubblefield Barbara Blanchard Toni L Richards Gaynor A Larson Yujun He Qian Huang Aik-Choon Tan Dabing Zhang Timothy A Benke John R Sladek Nancy R Zahniser Chuan-Yuan Li 2012Cell Research2012,22,2:14
18Impact of anthropogenic activities on the sediment microbial communities of Baiyangdian shallow lake显示文摘Microorganisms are recognized as sensors of external disturbance in freshwater ecosystems.In this study,sediment samples from regions with strong human activity interference(four sites),moderate human activity interference(five sites)and minor human activity interference(five sites)in Baiyangdian Lake were collected;and their physiological and chemical properties and heavy metals contents were analyzed.The structures of bacterial and fungal communities were tested using 16S ribosomal Ribonucleic Acid(rRNA)and Internal Transcribed Spacer 2(ITS2)high-throughput sequencing technologies.The results indicated that Proteobacteria was the most abundant bacterial phylum.Ascomycota,Basidiomycota and Ciliophora were the dominant phyla of fungi.Obvious differences of microbial genera among the three regions were observed,especially fungal genera.With intensified disturbance by human activities,the Simpson and Shannon indices of bacteria significantly decreased.The fungal communities were clustered into three groups in accordance with the different human disturbance levels.The bacterial communities of sediment samples under moderate and minor human disturbance appeared similar,but different from those under strong human disturbance.Redundancy analysis indicated that zinc,total phosphorus,copper,and lead were the dominant factors that influenced the bacterial community.Nitrifiers and sulfate-reducing bacteria were influenced by pH,nitrate(NO3 ),and total nitrogen.The fungal community was significantly affected by total phosphorus.This study reveals that sediment microbial community structures among different regions of a shallow lake are mainly impacted by human activities.Wenjun Wang Yujun Yi Yufeng Yang Yang Zhou Shanghong Zhang Xuan Wang Zhifeng Yang 2020International Journal of Sediment Research2020,35,2:14
19Predicting Cadmium Safety Thresholds in Soils Based on Cadmium Uptake by Chinese Cabbage显示文摘Cadmium(Cd), a common toxic heavy metal in soil, has relatively high bioavailability, which seriously threatens agricultural products. In this study, 8 different soils with contrasting soil properties were collected from different regions in China to investigate the Cd transfer coefficient from soil to Chinese cabbage(Brassica chinensis L.) and the threshold levels of Cd in soils for production of Chinese cabbage according to the food safety standard for Cd. Exogenous Cd(0–4 mg kg^(-1)) was added to the soils and equilibrated for 2 weeks before Chinese cabbage was grown under greenhouse conditions. The influence of soil properties on the relationship between soil and cabbage Cd concentrations was investigated. The results showed that Cd concentration in the edible part of Chinese cabbage increased linearly with soil Cd concentration in 5 soils, but showed a curvilinear pattern with a plateau at the highest dose of exogenous Cd in the other 3 soils. The Cd transfer coefficient from soil to plant varied significantly among the different soils and decreased with increasing soil p H from 4.7 to 7.5. However, further increase in soil pH to > 8.0 resulted in a significant decrease in the Cd transfer coefficient. According to the measured Cd transfer coefficient and by reference to the National Food Safety Standards of China, the safety threshold of Cd concentration in soil was predicted to be between 0.12 and 1.7 mg kg^(-1) for the tested soils. The predicted threshold values were higher than the current soil quality standard for Cd in 5 soils, but lower than the standard in the other 3 soils. Regression analysis showed a significant positive relationship between the predicted soil Cd safety threshold value and soil p H in combination with soil organic matter or clay content.LU Junhe YANG Xinping MENG Xuchao WANG Guoqing LIN Yusuo WANG Yujun ZHAO Fangjie 2017Pedosphere2017,27,3:13
20Meeting 24-h movement guidelines: Prevalence, correlates, and the relationships with overweight and obesity among Chinese children and adolescents显示文摘Background:Meeting 24-h movement guidelines by children and adolescents has been associated with improved indicators of health,although it has been under-studied in China.Hence,this study aimed to investigate the prevalence of meeting the 24-h movement guidelines,its correlates,and its relationships with body mass index in children and adolescents in China.Methods:Cross-sectional data from the 2017 Youth Study in China of 114,072 children and adolescents(mean age=13.75 years,49.18%boys)were used.Meeting 24-h movement guidelines(60 min of daily moderate-to-vigorous physical activity,2 h of daily leisure screen time,911 h and 810 h nightly sleep duration for 613-year-olds and 1417-year-olds,respectively)and height and weight of all participants were assessed.The prevalence of meeting the 24-h movement guidelines and World Health Organization weight status categories were determined.Generalized linear models were used to determine the correlates of meeting the 24-h movement guidelines and the relationships of meeting the 24-h movement guidelines with overweight(OW)and obesity(OB).Results:Only 5.12%of Chinese children and adolescents met the 24-h movement guidelines,and 22.44%were classified as OW/OB.Older children and adolescents were less likely to meet the 24-h movement guidelines.Parental education level and family income were positively related to meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines showed lower odds ratios for OW/OB.Compared with participants meeting the 24-h movement guidelines,boys in 4th6th grades met none of the recommendations(OR=1.22,95%CI:1.061.40),met the screen time recommendation only(OR=1.13,95%CI:1.011.28),met the nightly sleep duration recommendation only(OR=1.14,95%CI:1.031.28),and had significantly higher odds ratios for OW/OB.Similar trends were observed for girls in 4th6th grades:meeting none of the guidelines(OR=1.35,95%CI:1.141.59),meeting sleep duration guidelines only(OR=1.23,95%CI:1.081.39),and meeting moderate-to-vigorous physical activity+nightly sleep duration guidelines(OR=1.24,95%CI:1.011.54).For girls in 7th9th grades,the following trend was observed:meeting none of the guidelines(OR=1.30,95%CI:1.011.67).Conclusion:Very few Chinese children and adolescents met the 24-h movement guidelines.Age(negatively correlated),parental education level,and family income(both positively correlated)were correlates of meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines were more likely to have lower risks for OW/OB,especially in the youngest age group(Grades 46);and girls in the middle age group(Grades 79)were also more likely to have lower risks for OW/OB.Further research studies should explore additional correlates and determinants for meeting the 24-h movement guidelines.Also,future studies should use longitudinal or interventional designs to determine the relationships between meeting the 24-h movement guidelines and OW/OB and other health indicators,while taking sex and age differences into account.Si-Tong Chen Yang Liu Mark S.Tremblay Jin-Tao Hong Yan Tang Zhen-Bo Cao Jie Zhuang Zheng Zhu Xueping Wu Lijuan Wang Yujun Cai Peijie Chen 2021Journal of Sport and Health Science2021,10,3:12
返回顶部 每页显示:
共40页 首页 上一页 第1页 下一页 末页 /40 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费