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1Photochemical pollution in Lanzhou, China - A case study显示文摘The photochemical air pollution in Xigu district of Lanshou city, Gansu Province was studied during a period of 1981-1984. The extremely high NMHC/NOx ratio and ozone level elevation after rain have been noticed. A series of outdoor and indoor reaction chamber simulation experiments conducted in order to understand the specific conditions. The ozone formation under NMHC/NOx condition and the possible reason for high ozone concentration after rain are discussed.Tang Xiaoyan , Li Jinglong, Dong ZhenXing, Wang Yuying,Wang Wenxing , Qi Liwen, Liu Xiling, Zhang Yutian, Zhang Xuejin,Tian Bingshen, Jin Suwen , Yang Lingqing and Zhang Yixin Department of Technical Physics,Peking University, Beijing, China. Chinese Reaearch Academy of Eavironmental Sciences, Beijing,China. Gansu Provincial Environmental Research Institute, Lanshou, China. Lanshou Petrochemical Engineering Institute, Lanshou, China. 1989Journal of Environmental Sciences1989,1,1:15
2Generation of a precise Oct4-hrGFP knockin cynomolgus monkey model via CRISPR/Cas9-assisted homologous recombination显示文摘Yiqiang Cui Yuyu Niu Jiankui Zhou Yongchang Chen Yiwei Cheng Shangang Li Zongyong Ai Chu Chu Hong Wang Bo Zheng Xuejin Chen Jiahao Sha Xuejiang Guo Xingxu Huang Weizhi Ji 2018Cell Research2018,28,3:13
3Transgenic rhesus monkeys carrying the human MCPH1 gene copies show human-like neoteny of brain development显示文摘Brain size and cognitive skills are the most dramatically changed traits in humans during evolution and yet the genetic mechanisms underlying these human-specific changes remain elusive.Here,we successfully generated 11 transgenic rhesus monkeys(8 first-generation and 3 second-generation)carrying human copies of MCPH1,an important gene for brain development and brain evolution.Brain-image and tissue-section analyses indicated an altered pattern of neural-cell differentiation,resulting in a delayed neuronal maturation and neural-fiber myelination of the transgenic monkeys,similar to the known evolutionary change of developmental delay(neoteny)in humans.Further brain-transcriptome and tissue-section analyses of major developmental stages showed a marked human-like expression delay of neuron differentiation and synaptic-signaling genes,providing a molecular explanation for the observed brain-developmental delay of the transgenic monkeys.More importantly,the transgenic monkeys exhibited better short-term memory and shorter reaction time compared with the wild-type controls in the delayed-matching-to-sample task.The presented data represent the first attempt to experimentally interrogate the genetic basis of human brain origin using a transgenic monkey model and it values the use of non-human primates in understanding unique human traits.Lei Shi Xin Luo Jin Jiang Yongchang chen Cirong Liu Ting Hu Min Li Qiang Lin Yanjiao Li Jun Huang Hong Wang Yuyu Niu Yundi Shi Martin Styner Jianhong Wang Yi Lu Xuejin Sun Hualin Yu Weizhi Ji Bing Su 2019National Science Review2019,6,3:12
4Friction moment analysis of space gyroscope bearing with ribbon cage under ultra-low oscillatory motion显示文摘This paper presents the model of calculating the total friction moment of space gyroscope ball bearings which usually work under ultra-low oscillatory motion and are very sensitive to the friction moment. The aim is to know the proportion of the friction moment caused by each frictional source in the bearing's total friction moment, which is helpful to optimize the bearing design to deduce the friction moment. In the model, the cage dynamic equations considering six degree-of-freedom and the balls dynamic equations considering two degree-of-freedom were solved.The good trends with different loads between the measured friction moments and computational results prove that the model under constant rate was validated. The computational results show that when the speed was set at 5 r/min, the bearing's maximum total friction moment when oscillation occurred was obviously larger than that occurred at a constant rate. At the onset of each oscillatory motion, the proportion of the friction moment caused by cage in the bearing's total friction moment was very high, and it increased with the increasing speed. The analyses of different cage thicknesses and different clearances between cage pocket and ball show that smaller thickness and clearance were preferred.Jiang Shaona Chen Xiaoyang Gu Jiaming Shen Xuejin 2014Chinese Journal of Aeronautics2014,27,5:5
5Nuclear reprogramming: the zygotic transcription program is established through an“erase-and-rebuild” strategy显示文摘卵母细胞显示母亲特定的基因表达式侧面,它被换到当染色质的一个单倍体集合被传递到发展成一个胚胎的受精卵时, zygotic 介绍。位于这抄写 reprogramming 下面的机制当前是未知的。等到当抄写在幼芽的泡卵母细胞被关掉时,一般抄写因素和 transcriptional 管理者的一个范围从染色质被分裂,这里,我们表明那。染色质因素(CF ) 的全球分离破坏在染色质和 CF 之间的物理接触并且在功能的水平导致母亲的抄写节目的檫除。与染色质论坛分开的批评抄写因素和管理者遗体延长了时期,并且立即在专业版以后与染色质成为 re-associated 原子形成。Thisis 由象 DNA 和抄写那样的原子功能的重建跟随了速度集合。我们建议母亲的抄写节目在卵子发生期间被擦掉产生相对天真的染色质, zygotic 抄写节目是在授精以后的重建的重新。这个过程作为“ erase-and-rebuild ”被称为过程,它被用来重设抄写节目,和最可能的其它原子过程也,从母亲的到胚胎的。我们进一步在伴随的纸出现(高 T,等,房间物件 2007;17:135-150 .) 一样的策略也被采用到改编 transcriptional,这在体细胞介绍原子转移和单性生殖,建议这当模特儿在早胚胎开始期间对 transcriptional reprogramming 的所有形式普遍适用。从染色质的 CF 的排水量也为抄写沉默的现象提供解释在期间对 zygotic 转变母亲。Feng Sun Haiyan Fang Ruizhen Li Tianlong Gao Junke Zheng Xuejin Chen Wenqin Ying Hui Z Sheng 2007Cell Research2007,17,2:5
6The Promotion Effect of Low-Molecular Hydroxyl Compounds on the Nano-Photoelectrocatalytic Degradation of Fulvic Acid and Mechanism显示文摘A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.Yifan Dong Jinhua Li Xuejin Li Baoxue Zhou 2016Nano-Micro Letters2016,8,4:4
7THE MANAGEMENT AND RESEARCH OF GEOGRAPHICAL NAMES USING GEOGRAPHICAL INFORMATION SYSTEM显示文摘Based on the combination of Geographical information system(GIS)with the research ofToponymy,some foundational problems of the Geographical Name Information System(GINS)are discussed in this paper.The present situation of Toponymical research is anal-ysed and the necessity of introducing the GIS tools to the research of Toponymy is demon-strated.The conceptual model of the GNIS and the structure of Geographical name Database(GND)are discussed.The basic functions of the GNIS software for management and re-search of geographical name are suggested.Some issues are stated such as the applicationand potential of the combination of GIS with CAD in the management and research of To-ponymy,the combination of GNIS with other spatial information system and sharing the in-formation with each other,the research and development of GNIS, etc.Yu Guangming Chen Ping Wu Xuejin(Department of Geography) 1992湖北科技学院学报1992,23,3:4
8Fabrication and oxidation resistance of silicon nitride fiber reinforced silica matrix wave-transparent composites显示文摘Wave-transparent ceramic matrix composites for the high temperature use should possess excellent oxidation resistance. In this work, Si3N4f/SiO2 composites with different fiber content were fabricated by filament winding and sol gel method. The oxidation resistance was investigated by tracking the response of flexural strength to the testing temperature. The results show that the flexural strength and toughness of the composites with fiber content of over 37% can reach high levels at around 175.0 MPa and 6.2 MPa m^1/2, respectively. After 1 h oxidation at 1100℃, the flexural strength drops a lot but can still reach 114.4 MPa, which is high enough to ensure the safety of structures. However, when the oxidation temperature rises to 1200–1400℃, the flexural strengths continue to fall to a relatively low level at 50.0–66.4 MPa. The degradation at high temperatures is caused by the combination of over strong interfacial bonding, the damage of fiber and the crystallization of silica matrix.Xuejin Yang Bin Li Duan Li Changwei Shao Changrui Zhang Chunrong Zou Kun Liu 2019Journal of Materials Science & Technology2019,35,12:4
9Genetic basis of high aroma and stress toleranee in the oolong tea cultivar genome显示文摘Tea plants(Camellia sinensis)are commercially cultivated in>60 countries,and their fresh leaves are processed into tea,which is the most widely consumed beverage in the world.Although several chromosome-level tea plant genomes have been published,they collapsed the two haplotypes and ignored a large number of allelic variations that may underlie important biological functions in this species.Here,we present a phased chromosome-scale assembly for an elite oolong tea cultivar,'Huangdan',that is well known for its high levels of aroma.Based on the two sets of haplotype genome data,we identi fi ed numerous genetic variations and a substantial proportion of allelic imbalance related to important traits,including aroma-and stress-related alleles.Comparative genomics revealed extensive structural variations as well as expansion of some gene families,such as terpene synthases(TPSs),that likely contribute to the high-aroma characteristics of the backbone parent,underlying the molecular basis for the biosynthesis of aroma-related chemicals in oolong tea.Our results uncovered the genetic basis of special features of this oolong tea cultivar,providing fundamental genomic resources to study evolution and domestication for the economically important tea crop.Pengjie Wang Jiaxin Yu Shan Jin Shuai Chen Chuan Yue Wenling Wang Shuilian Gao Hongli Cao Yucheng Zheng Mengya Gu Xuejin Chen Yun Sun Yuqiong Guo Jiangfan Yang Xingtan Zhang Naixing Ye 2021Horticulture Research2021,8,1:4
10The Inhibition Effect of Tert-Butyl Alcohol on the TiO_2 Nano Assays Photoelectrocatalytic Degradation of Different Organics and Its Mechanism显示文摘The inhibition effect of tert-butyl alcohol(TBA), identified as the·OH radical inhibitor, on the TiO_2 nano assays(TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and harddegradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of·OH radicals by TBA in TNA photoelectrocatalytic process.Xuejin Li Jinhua Li Jing Bai Yifan Dong Linsen Li Baoxue Zhou 2016Nano-Micro Letters2016,8,3:4
11Identification of PAL genes related to anthocyanin synthesis in tea plants and its correlation with anthocyanin content显示文摘The phenylalanine ammonia-lyase(PAL)gene family in tea plants(Camellia sinensis L.)encodes the enzyme that catalyzes the first reaction of the phenylpropane metabolic pathway.The present study aimed to characterize the PAL genes in tea plants,and get better insights on the CsPALs in anthocyanins accumulation.Seven CsPAL genes were identified and characterized in tea plants by bioinformatics analysis.Systematic analysis of CsPALs was conducted for its phylogenetic relationship,gene structure,chromosomal location,and protein conserved motifs based on tea plant genome.The cis-elements of CsPALs were responsive to light,abiotic stress,hormone,and MYB-binding site.Furthermore,tissuespecific expression analysis showed that CsPAL4 was expressed preferentially in young leaves and buds.Correlation analysis was performed in purple-leaf tea with anthocyanin components,and it was suggested that CsPAL4 was closely related with different anthocyanin accumulated,especially with cyanidin 3-O-galactoside,cyanidin 3-O-glucoside,and delphinidin 3-O-glucoside.Additionally,the putative upstream regulation factors CsMYBs(CsMYB59,CsARR1,CsSRM1,CsMYB101,and CsMYB52)and CsbHLHs(CsbHLH104,CsbHLH3,CsbIM1,CsTCP14,and CsPIF4)could bind to the promoter of CsPALs,thereby activating its transcription.This study provides a theoretical basis for further research to elucidate the functions of the CsPAL genes.Xuejin Chen Pengjie Wang Mengya Gu Binghao Hou Churan Zhang Yucheng Zheng Yun Sun Shan Jin Naixing Ye 2022Horticultural Plant Journal2022,8,3:4
12Conversion of female germline stem cells from neonatal and prepubertal mice into pluripotent stern cells显示文摘Hu Wang Manxi Jiang Haiwei Bi Xuejin Chen Lin He Xiaoyong Li Ji Wu 2014Journal of Molecular Cell Biology2014,8,2:3
13Elastohydrodynamic lubrication properties and friction behaviors of several ester base stocks显示文摘This paper reports a series of studies on the lubricant properties,elastohydrodynamic film thickness,and coefficients of friction of several commercially available ester base stocks,i.e.,diisooctyl phthalate(DIOP),diisodecyl phthalate(DIDP),diisotridecyl phthalate(DITDP),diisooctyl sebacate(DOS),diisotridecyl sebacate(DTDS),trihydroxymethylpropyl trioleate(TMPTO),and pentaerythritol tetraoleate(PETO).The results include densities and viscosities from 303 to 398 K,and elastohydrodynamic lubricant film thicknesses and friction in the boundary,mixed and full-film lubrication regimes measured at several temperatures,loads,and speeds.These ester base stocks have different lubrication abilities owing to their chain lengths,geometric configurations,and molecular rigidity.This study provides quantitative insight into the use of ester-based lubricants for low friction through the entire lubrication regime(boundary to full film)by utilization of suitable type and size of the ester base stocks.Yifeng HE Thomas J.ZOLPER Pinzhi LIU Yuzhen ZHAO Xingliang HE Xuejin SHEN Hongwei SUN Qinghua DUAN Qian WANG 2015Friction2015,3,3:3
14Construction of Hierarchical Nanostructured N-doped TiO2 Immobilized Activated Carbon Fiber Porous Composites for Toluene Removal显示文摘The hierarchical nanostructured N-doped TiO2 immobilized activated carbon fiber(N-TiO2/ACF)porous composites are fabricated to removal dynamic toluene gas.The results show that nitrogen ions doping and ACF modification can decrease the band gap of TiO2,leading to red shift toward visible light region.Interestingly,N-TiO2/ACF exhibits strongly synergistic effect owing to high surface area,good crystallinity,enhanced bandgap structure and light harvesting.The toluene removal rate of N-TiO2/ACF composites is 2.29 times higher than that of TiO2.The N-TiO2/ACF for toluene degradation followed the Langmuir-Hinshelwood kinetic model,and the rate constant is enhanced 8 times compared with TiO2.The possible photodegradation pathway and mechanisms are proposed.Li Yuwei Li Wei Li Meng Liu Fang Qi Xuejin Wang Yongqiang 2020China Petroleum Processing & Petrochemical Technology2020,22,3:3
15Surface Exciton-Plasmon Polariton Enhanced Light Emission via Integration of Single Semiconductor Nanowires with Metal Nanostructures显示文摘The light emission enhancement behavior from single ZnO nanowires integrated with metallic contacts is investigated by micro-photoluminescence measurements.Apart from surface plasmon polaritons at the air/metal interface,the emission of a single ZnO nanowire can be coupled into guided modes of surface exciton-plasmon polaritons(SEPPs).The out-coupling avenues of SEPP guided modes are modeled in the presence of nanostructures,such as corrugation and gratings,on the metal surface.The guided modes of SEPPs in metal-contacted ZnO nanowires are calculated using the effective index method.The enhanced light emission from single semiconductor nanowires shows promise for use in highly efficient nano-emitters and nano-lasers,as well as macroscopic solid state light sources with very high efficiency.Xuejin Zhang Pengwei Wang Xinzheng Zhang Jun Xu Yongyuan Zhu Dapeng Yu 2009Nano Research2009,2,1:2
16Experimental investigation of EHD grease lubrication in finite line contacts显示文摘The objective of this study was to investigate the grease-lubricated film-forming mechanisms in the finite line contact and to improve the grease-lubricated finite line contact’s film-forming capacity.An elastohydrodynamic lubrication(EHL) test rig with two interferometry microscopes,which could simultaneously monitor two different contact locations in the finite line contact,was constructed in order to study the influences of the grease thickener formulation on the film thickness and lubrication condition.By using the relative light intensity method,the thickness maps of the grease-lubricated film were calculated from the interferometer images captured by the two microscopes.The test results revealed that the grease thickener’s formulation had remarkable effects on film formation and the perturbation of film thickness.For the lithium-based grease,the film’s thickness near the two ends of the roller was prone to severe perturbation caused by the conglomeration of clumps that were hard to shear.For the aluminum-complex-based grease,the fibers tended to accumulate in the middle of the roller rather than at the two ends.The urea-based grease could be easily sheared into smaller particles.In addition to the straight-line profile rollers,the logarithmic profile rollers were tested and found to effectively enhance the axial grease flow,increase the axial shear stress,and thus shear more fibers into particles within the contact area.Zhijian WANG Xuejin SHEN Xiaoyang CHEN Dehua TAO Lei SHI Shuangbiao LIU 2019Friction2019,7,3:2
17Epitaxial growth of hyperbranched Cu/Cu2O/CuO coreshell nanowire heterostructures for lithium-ion batteries显示文摘nano 建筑学的小心的设计和期望的活跃材料的聪明的杂交能导致更先进的性质。这里,我们设计了新奇层次分叉 Cu/Cu 2 由联合一个灵巧的热水的方法和随后的控制氧化过程的 O/CuO heteronanostructure。在分支和脊梁之间的好结构和取向附生的关系被高分辨率的传播电子显微镜学调查。而且,分支生长的进化也在 Cu nanowire 表面的渐渐的氧化期间被观察了。试验性的结果建议经由二拍子的圆舞暴露进程要表现到改变湿度以便完成的表面氧化需要优化了核心壳的形成结构化的分叉的建筑学。最后,象在锂离子电池的阳极材料的如此的一个层次框架的功能的 proof-of-concept 被表明。分叉的核心壳 heterostructure 由几个工具改进电池性能:取向附生地成年的分支提供的(i) 为到卷变化的提高的电解质可接近性和高抵抗的一个高表面区域由 Li+ 置闰 / 抽取导致了;(ii ) 有它的明确的异质接面的核心壳结构增加在 lithiation 期间便于有效费用运输的接触区域;(iii ) 铜核心象提供结构的加强一样充当一个当前的收集者。Yuxin Zhao Ying Zhang Hu Zhao Xuejin Li Yanpeng Li Ling wen Zifeng Yan Ziyang Huo 2015Nano Research2015,8,8:2
18ELASTOHYDRODYNAMIC LUBRICATION OF LOGARITHMIC PROFILE ROLLER CONTACTS显示文摘An account of numerical solutions to the isothermal and flooded elastohydrodynamic lubrication(EHL)of a logarithmic profile roller,which is rolling over a flat plane,is given The analysis takes account of sideways flow of lubricant in the inlet region of the contact When the results are presented in suitable non dimensional groups,it is shown that more uniformly pressure and shape of the film distributing in axial direction is taken place under light loading As the increase of the load,the end closure is displayed and the oil pressure rises sharply at the ends The seal action formed by the end closure makes the film thickness a little And the minimum film thickness is transferred from the central to the ends and the value is reduced rapidly As the increase of the speed,the end closure becomes much serious The optimum crowning value obtained in EHL state is larger than the design value obtained in elastostatic contact state for the same working conditions In order to verify the correctness of theory,optical interferometry is applied to measure the oil film thickness between a logarithmic profiled roller and a glass plate under pure rolling conditions It is found the agreement between numerical solutions and experiments is very good.Chen Xiaoyang, Shen Xuejin (Research Institute of Bearings,Shanghai University) Xu Wen, Ma Jiaju (Zhejiang University) 2001Chinese Journal of Mechanical Engineering2001,14,4:2
19Myeloid-derived suppressor cells as immunosuppressive regulators and therapeutic targets in cancer显示文摘Myeloid-derived suppressor cells(MDSCs)are a heterogenic population of immature myeloid cells with immunosuppressive effects,which undergo massive expansion during tumor progression.These cells not only support immune escape directly but also promote tumor invasion via various non-immunological activities.Besides,this group of cells are proved to impair the efficiency of current antitumor strategies such as chemotherapy,radiotherapy,and immunotherapy.Therefore,MDSCs are considered as potential therapeutic targets for cancer therapy.Treatment strategies targeting MDSCs have shown promising outcomes in both preclinical studies and clinical trials when administrated alone,or in combination with other anticancer therapies.In this review,we shed new light on recent advances in the biological characteristics and immunosuppressive functions of MDSCs.We also hope to propose an overview of current MDSCs-targeting therapies so as to provide new ideas for cancer treatment.Kai Li Houhui Shi Benxia Zhang Xuejin Ou Qizhi Ma Yue Chen Pei Shu Dan Li Yongsheng Wang 2021Signal Transduction and Targeted Therapy2021,6,11:2
20Noggin versus basic fibroblast growth factor on the differentiation of human embryonic stem cells显示文摘The difference between Noggin and basic fibroblast growth factor for the neural precursor differen-tiation from human embryonic stem cells has not been studied. In this study, 100 μg/L Noggin or 20 μg/L basic fibroblast growth factor in serum-free neural induction medium was used to differen-tiate human embryonic stem cells H14 into neural precursors using monolayer differentiation. Two weeks after induction, significantly higher numbers of neural rosettes formed in the Noggin-induced group than the basic fibroblast growth factor-induced group, as detected by phase contrast micro-scope. Immunofluorescence staining revealed expression levels of Nestin, β-III Tubulin and Sox-1 were higher in the induced cells and reverse-transcription PCR showed induced cells expressed Nestin, Sox-1 and Neurofilament mRNA. Protein and mRNA expression in the Noggin-induced group was increased compared with the basic fibroblast growth factor-induced group. Noggin has a greater effect than basic fibroblast growth factor on the induction of human embryonic stem cell differentiation into neural precursors by monolayer differentiation, as Noggin accelerates and in-creases the differentiation of neural precursors.Yan Zhang Junmei Zhou Zhenfu Fang Manxi Jiang Xuejin Chen 2013Neural Regeneration Research2013,8,23:2
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