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284篇 您的检索式:作者名="LI LiFeng"
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1Deep structure beneath the southwestern section of the Longmenshan fault zone and seimogenetic context of the 4.20 Lushan M_S7.0 earthquake显示文摘Magnetotelluric measurements were carried out along two profiles across the middle and southwestern sections of the Longmenshan fault zone(LMSf)from 2009 to 2011,after the 2008 Wenchuan MW7.9 earthquake.The former profile crosses the Wenchuan event epicenter and the latter one crosses 2013 Lushan MS7.0 event epicenter.The data were analyzed using advanced processing techniques,including phase tensor and two-dimensional inversion methods,in order to obtain reliable 2-D profiles of the electrical structure in the vicinity of the two earthquakes.A comparison of the two profiles indicates both similarities and differences in the deep crustal structure of the LMSf.West of the southwestern section,a crustal high conductivity layer(HCL)is present at about 10 km depth below the Songpan-Garzêblock;this is about 10 km shallower than that under the middle section of the LMSf.A high resistivity body(HRB)is observed beneath the southwestern section,extending from the near surface to the top of upper mantle.It has a smaller size than the HRB observed below the middle section.In the middle section,there is a local area of decreased resistivity within the HRB but there is absence of this area.The 2013 Lushan earthquake occurred close to the eastern boundary of HRB and the Shuangshi-Dachuan fault,of which the seismogenic context has both common and different features in comparison with the 2008 Wenchuan event.On a large scale,the 2013 Lushan earthquake is associated with the HCL and deformation in the crust including HCL of the eastern Tibetan Plateau.In order to assess seismic risk,it is important to consider both the stress state and the detailed crustal structure in different parts of the LMSf.ZHAN Yan ZHAO GuoZe UNSWORTH Martyn WANG LiFeng CHEN XiaoBin LI Tao XIAO QiBin WANG JiJun TANG Ji CAI JunTao WANG YanZhao 2013Chinese Science Bulletin2013,58,28:39
2Age-related macular degeneration: Epidemiology, genetics, pathophysiology, diagnosis, and targeted therapy显示文摘Age-related macular degeneration (AMD) is a complex eye disorder and is the leading cause of incurable blindness worldwide in the elderly. Clinically, AMD initially affects the central area of retina known as the macula and it is classified as early stage to late stage (advanced AMD). The advanced AMD is classified into the nonexudative or atrophic form (dry AMD) and the exudative or neovascular form (wet AMD). More severe vision loss is typically associated with the wet form. Multiple genetic factors, lipid metabolism, oxidative stress and aging, play a role in the etiology of AMD. Dysregulation in genetic to AMD is established to 46%–71% of disease contribution, with CFH and ARMS2/HTRA1 to be the two most notable risk loci among the 103 identified AMD associated loci so far. Chronic cigarette smoking is the most proven consistently risk living habits for AMD. Deep learning algorithm has been developed based on image recognition to distinguish wet AMD and normal macula with high accuracy. Currently, anti-vascular endothelial growth factor (VEGF) therapy is highly effective at treating wet AMD. Several new generation AMD drugs and iPSC-derived RPE cell therapy are in the clinical trial stage and are promising to improve AMD treatment in the near future.Yanhui Deng Lifeng Qiao Mingyan Du Chao Qu Ling Wan Jie Li Lulin Huang 2022Genes & Diseases2022,9,1:17
3Sensitive High Resolution Ion Micro-Probe U-Pb Zircon Geochronology and Geochemistry of Mafic Rocks from the Pulan-Xiangquanhe Ophiolite,Tibet:Constraints on the Evolution of the Neo-tethys显示文摘在西藏的西方的 Yarlung Tsangpo 缝术地区的 Pulan-Xiangquanhe ophiolite 详细为它的地球化学,地球年代学,和构造含意被调查。敏感高分辨率离子标明日期的微探查的锆石 U-Pb 表明在从 Xugugab, Mapam Yum 公司和 La'nga 公司的三个地点的 ophiolite 的辉绿岩在 122.3 点是过时的 ?A?????????????? 畐慬? 楘湡照慵桮? 传桰潩楬整??XIA Bin LI Jianfeng XU Lifeng WANG Ran YANG Zhiqing 2011Acta Geologica Sinica(English Edition)2011,85,4:16
4Efficacy and safety evaluation of intravenous infusion of cervus and cucumis polypeptides for treatment of avascular necrosis of the femoral head: a randomized clinical trial显示文摘OBJECTIVE: To investigate the efficacy and safety of intravenous cervus and cucumis polypeptides for treating avascular necrosis of the femoral head(ANFH) in regard to pain and hip function in a randomized clinical trial.METHODS: A total of 96 subjects with ANFH who were recruited at the Orthopaedic Hospital Affiliated with Hebei United University and Qian Hai Femoral Head Hospital of Beijing were assigned by lottery to an intervention group(n = 48) or a control group(n = 48). All subjects underwent physical therapy and rehabilitation exercises. In addition,subjects in the intervention group were given intravenous infusions of cervus and cucumis polypeptides. Visual analogue scale(VAS), Harris hip score,and radiography or magnetic resonance imaging were applied to assess all subjects at the beginning of treatment and 3, 6, and 9 months afterward. All the subjects were followed up for 2 years.RESULTS: At the beginning of treatment, there were no statistically significant differences between the two groups in terms of the general condition of patients or the VAS and Harris hip scores(all P > 0.05). At 3, 6, and 9 months after treatment,however, the VAS score decreased and the Harris hip score increased in all patients, with the improvement of intervention group significantly greater than that of the control group(P < 0.05).The total effectiveness rates for the intervention and control groups were 89.58% and 70.83%, respectively, with the difference being statistically significant(P < 0.05). There was no statistically significant difference between the two groups in terms of the safety of the injections(P > 0.05).CONCLUSION: Intravenous infusion of cervus and cucumis polypeptides relieved pain and improved hip function of subjects with ANFH.Thus, the intravenous infusion of cervus and cucumis polypeptides was a safe, effective treatment for ANFH.Wei Liyou Zhang Hongwei Li Xinmin Yang Chunyan Wang Guoqiang Zhang Lifeng Cui Mingwu Han Lijun 2016Journal of Traditional Chinese Medicine2016,36,1:15
5SHRIMP zircon U-Pb dating for gabbro from the Tiding ophiolite in Tibet显示文摘WANG Ran XIA Bin ZHOU Guoqing ZHANG Yuquan YANG Zhiqing LI Wenqian WEI Dongliang ZHONG Lifeng XU Lifeng 2006Chinese Science Bulletin2006,51,14:14
6Human umbilical cord mesenchymal stem cell-loaded amniotic membrane for the repair of radial nerve injury显示文摘In this study,we loaded human umbilical cord mesenchymal stem cells onto human amniotic membrane with epithelial cells to prepare nerve conduits,i.e.,a relatively closed nerve regeneration chamber.After neurolysis,the injured radial nerve was enwrapped with the prepared nerve conduit,which was fixed to the epineurium by sutures,with the cell on the inner surface of the conduit.Simultaneously,a 1.0 mL aliquot of human umbilical cord mesenchymal stem cell suspension was injected into the distal and proximal ends of the injured radial nerve with 1.0 cm intervals.A total of1.75×107cells were seeded on the amniotic membrane.In the control group,patients received only neurolysis.At 12 weeks after cell transplantation,more than 80%of patients exhibited obvious improvements in muscular strength,and touch and pain sensations.In contrast,these improvements were observed only in 55–65%of control patients.At 8 and 12 weeks,muscular electrophysiological function in the region dominated by the injured radial nerve was significantly better in the transplantation group than the control group.After cell transplantation,no immunological rejections were observed.These findings suggest that human umbilical cord mesenchymal stem cell-loaded amniotic membrane can be used for the repair of radial nerve injury.Zhi Li Hanjiao Qin Zishan Feng Wei Liu Ye Zhou Lifeng Yang Wei Zhao Youjun Li 2013Neural Regeneration Research2013,8,36:13
7Transplantation of placenta-derived mesenchymal stem cell-induced neural stem cells to treat spinal cord injury显示文摘Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta-derived mesenchymal stem cells were induced to differentiate into neural stem cells, which were then transplanted into the spinal cord after local spinal cord injury in rats. The motor functional recovery and pathological changes in the injured spinal cord were observed for 3 successive weeks. The results showed that human placenta-derived mesenchymal stem cells can differentiate into neuron-like cells and that induced neural stem cells contribute to the restoration of injured spinal cord without causing transplant rejection. Thus, these cells promote the recovery of motor and sensory functions in a rat model of spinal cord injury. Therefore, human placenta-derived mesenchymal stem cells may be useful as seed cells during the repair of spinal cord injury.Zhi Li Wei Zhao Wei Liu Ye Zhou Jingqiao Jia Lifeng Yang 2014Neural Regeneration Research2014,9,24:13
8Early Permian Tarim Large Igneous Province in northwest China显示文摘Tarim Large Igneous Province(TLIP)is the second Late Paleozoic LIPs in China after the recognition of Emeishan LIP,and is a hot research topic in geosciences.On the basis of the analysis of research history about TLIP,this paper summarizes the research result during last twenty years and suggests the key research area in the future.The residual distribution range of TLIP is up to 250000 km2,and the largest residual thickness is 780 m.The eruption of basalt happened during 290–288 Ma and belongs to LIPs magmatic event with fast eruption of magma.The lithological units of the TLIP include basalt,diabase,layered intrusive rock,breccia pipe mica-olivine pyroxenite,olivine pyroxenite,gabbro,ultramafic dyke,quartz syenite,quartz syenite porphyry and bimodal dyke.The basalt and diabase of TLIP exhibit OIB-like trace element patterns and enrichment of LILE and HFSE,and mainly belong to high TiO2series.There is an obvious difference in isotope among the basalt from Keping and the basalt and dibase from the northern Tarim Basin.The basalt from Keping with negative Nd and high REE value derives from enriched mantle,and the diabase and basalt from the northern Tarim Basin with positive Nd and low REE value are related to depleted mantle.The crust uplifting in the Early Permian and the development of picrite and large scale dyke and formation of large scale V-Ti-Magnetite deposit in Wajilitag area support the view that the TLIP is related to mantle plume.The TLIP has a temporal-spatial relationship with Permian basic to ultra-basic igneous rock,which is distributed widely in Central Asia,and they represent a tectono-magmatic event with very important geodynamic setting.This paper also suggests that the deep geological process,the relation with mantle plume,mineralization,the relation with environmental change and biological evolution,and the geodynamics of the TLIP will be the key research topics in the future.YANG ShuFeng CHEN HanLin LI ZiLong LI YinQi YU Xing LI DongXu MENG LiFeng 2013Science China Earth Sciences2013,56,12:12
9Relation of myocardial bridge to myocardial infarction:a meta-analysis显示文摘Hong Lifeng Liu Jun Luo Songhui Li Jianjun 2014Chinese Medical Journal2014,,5:12
10Root and shoot traits responses to phosphorus deficiency and QTL analysis at seedling stage using introgression lines of rice显示文摘Phosphorous(P) deficiency is a major restraint factor for crop production and plants have developed several mechanisms to adapt to low P stress.In this study,a set of 271 introgression lines(ILs) were used to characterize the responses of seedlings to low P availability and to identify QTLs for root traits,biomass,and plant height under P-deficiency and P-sufficiency conditions.Plant height,total dry weight,shoot dry weight,and root number were inhibited under P-deficiency,whereas maximum root length(MRL) and root-shoot ratio(RS) were induced by P-deficiency stress.Relative MRL(RMRL,the ratio of MRL under P-deficiency to MRL under P-sufficiency con-dition) and relative RS(RRS) were used to evaluate P-deficiency tolerance at the seedling stage.A total of 24 additive QTLs and 29 pairs of epistatic QTLs were detected,but only qRN4 was detected in both conditions.This suggested that different mechanisms may exist in both P supply levels.QTLs for adaptive traits(RMRL,RRS,RRV,and RRDW) and qRN4 consistently expressed to increase trait stabil-ity may contribute to P-deficiency tolerance.Twelve intervals were cluster regions of QTLs for P-deficiency tolerance,and one QTL(qRRS8) showed pleiotropic effects on P-deficiency tolerance and drought tolerance.These interesting QTLs can be used in marker-assisted breeding through the target ILs.Junzhou Li Yan Xie Anyong Dai Lifeng Liu Zichao Li 2009Journal of Genetics and Genomics2009,36,3:12
11Urban expansion in China and its effect on cultivated land before and after initiating'Reform and Open Policy'显示文摘Urbanization in China has expanded at an unprecedented speed since the declaration of 'Reform and Open Policy'and presented many challenges. Unbalanced regional development, appearance of super megacities and concomitant problems,and conflicts between urbanization and cultivated land protection are three critical problems that Chinese urbanization has to face. To develop new plans for foreseeable future urbanization in China, it is critical to understand the evolving history of cities across China. This study maps urban expansion of 60 typical Chinese cities based on large amount of remote sensing data and the labor-intensive image interpretation method, in order to understand the history of urban expansion from the 1970 s to 2013.Results showed that area of cities expanded 5.23 times compared to their area in the 1970 s. Urban expansion in China accelerated three times(1988–1996, 1999–2006, and 2009–2011) and decelerated three times(1997–1998, 2007–2008, and 2012–2013) over the 40 years. The urban area of South China expanded most significantly 9.42 times, while the urban area in Northeast China expanded only 2.37 times. The disparity among different administrative ranks of cities was even greater than(3.81 times) the differences among different regions. Super megacities have been continuously expanding at a fast rate(8.60-fold), and have not shown obvious signs of slowing down. The proportion of cultivated land among the land sources for urban expansion decreased to a small extent in the 1990 s, but cultivated land continues to be the major land source for urban expansion. Effective future urbanization needs controlling the expansion scale of large cities and reasonably developing medium and small cities, as well as balancing regional development.ZHANG ZengXiang WEN QingKe LIU Fang ZHAO XiaoLi LIU Bin XU JinYong YI Ling HU ShunGuang WANG Xiao ZUO LiJun LI Na LI MinMin SHI LiFeng ZENG Tian JU HongRun 2016Science China Earth Sciences2016,59,10:12
12Grey matter volume abnormalities in patients with bipolar I depressive disorder and unipolar depressive disorder:a voxelbased morphometry study显示文摘Bipolar disorder and unipolar depressive disorder(UD) may be different in brain structure. In the present study,we performed voxel-based morphometry(VBM) to quantify the grey matter volumes in 23 patients with bipolar I depressive disorder(BP1) and 23 patients with UD,and 23 age-,gender-,and educationmatched healthy controls(HCs) using magnetic resonance imaging. We found that compared with the HC and UD groups,the BP1 group showed reduced grey matter volumes in the right inferior frontal gyrus and middle cingulate gyrus,while the UD group showed reduced volume in the right inferior frontal gyrus compared to HCs. In addition,correlation analyses revealed that the grey matter volumes of these regions were negatively correlated with the Hamilton depression rating scores. Taken together,the results of our study suggest that decreased grey matter volume of the right inferior frontal gyrus is a common abnormality in BP1 and UD,and decreasedgrey matter volume in the right middle cingulate gyrus may be specifi c to BP1.Yi Cai Jun Liu Li Zhang Mei Liao Yan Zhang Lifeng Wang Hongjun Peng Zhong He Zexuan Li Weihui Li Shaojia Lu Yuqiang Ding Lingjiang Li 2015Neuroscience Bulletin2015,31,1:11
13Effect of extrusion speed on microstructure and mechanical properties of the Mg-Ca binary alloy显示文摘This work reported the effect of extrusion speeds on the microstructures and mechanical properties of Mg-Ca binary alloy.The results showed that yield strength of the as-extruded Mg-1.2wt.%Ca alloys decrease from∼360MPa to∼258MPa as the ram speed increases from 0.4mm/s to 2.4 mm/s,and the elongation increases from∼3.9%to∼12.2%.The microstructure changes from bimodal grain feature to the complete dynamical recrystallization(DRX)with increase of the extrusion speed.The ultrafine DRXed grains in size of∼0.85μm,the numerous nano-Mg_(2)Ca particles dispersing along the grain boundaries and interiors,as well as the high density of residual dislocations,should account for the high strength.It is believed that the high degree of dynamic recrystallization and the resulting texture randomization play the critical roles in the ductility enhancement of the high-speed extruded Mg alloys.Jingren Li Aiyue Zhang Hucheng Pan Yuping Ren Zhuoran Zeng Qiuyan Huang Changlin Yang Lifeng Ma Gaowu Qin 2021Journal of Magnesium and Alloys2021,9,4:9
14Wheat genomic study for genetic improvement of traits in China显示文摘Bread wheat(Triticum aestivum L.)is a major crop that feeds 40%of the world’s population.Over the past several decades,advances in genomics have led to tremendous achievements in understanding the origin and domestication of wheat,and the genetic basis of agronomically important traits,which promote the breeding of elite varieties.In this review,we focus on progress that has been made in genomic research and genetic improvement of traits such as grain yield,end-use traits,flowering regulation,nutrient use efficiency,and biotic and abiotic stress responses,and various breeding strategies that contributed mainly by Chinese scientists.Functional genomic research in wheat is entering a new era with the availability of multiple reference wheat genome assemblies and the development of cutting-edge technologies such as precise genome editing tools,highthroughput phenotyping platforms,sequencing-based cloning strategies,high-efficiency genetic transformation systems,and speed-breeding facilities.These insights will further extend our understanding of the molecular mechanisms and regulatory networks underlying agronomic traits and facilitate the breeding process,ultimately contributing to more sustainable agriculture in China and throughout the world.Jun Xiao Bao Liu Yingyin Yao Zifeng Guo Haiyan Jia Lingrang Kong Aimin Zhang Wujun Ma Zhongfu Ni Shengbao Xu Fei Lu Yuannian Jiao Wuyun Yang Xuelei Lin Silong Sun Zefu Lu Lifeng Gao Guangyao Zhao Shuanghe Cao Qian Chen Kunpu Zhang Mengcheng Wang Meng Wang Zhaorong Hu Weilong Guo Guoqiang Li Xin Ma Junming Li Fangpu Han Xiangdong Fu Zhengqiang Ma Daowen Wang Xueyong Zhang Hong-Qing Ling Guangmin Xia Yiping Tong Zhiyong Liu Zhonghu He Jizeng Jia Kang Chong 2022Science China(Life Sciences)2022,65,9:9
15MiR-181a-5p regulates 3T3-L1 cell adipogenesis by targeting Smad7 and Tcf7I2显示文摘Dan Ouyang Lifeng Xu Lihua zhang Dongguang Guo Xiaotong Tan Xiaofang Yu Junjie Qi Yaqiong Ye Qihong Liu Yongjiang Ma Yugu Li 2016Acta Biochimica et Biophysica Sinica2016,48,11:9
16Photocatalytic degradation kinetics and mechanism of pentachlorophenol based on superoxide radicals显示文摘The micron grade multi-metal oxide bismuth silicate (Bi 12 SiO 20,BSO) was prepared by the chemical solution decomposition technique.Photocatalytic degradation of pentachlorophenol (PCP) was investigated in the presence of BSO under xenon lamp irradiation.The reaction kinetics followed pseudo first-order and the degradation ratio achieved 99.1% after 120 min at an initial PCP concentration of 2.0 mg/L.The pH decreased from 6.2 to 4.6 and the dechlorination ratio was 68.4% after 120 min at an initial PCP concentration of 8.0 mg/L.The results of electron spin resonance showed that superoxide radical (O 2 · ) was largely responsible for the photocatalytic degradation of PCP.Interestingly,this result was different from that of previous photocatalytic reactions where valence band holes or hydroxyl radicals played the role of major oxidants.Some aromatic compounds and aliphatic carboxylic acids were determined by GC/MS as the reaction intermediates,which indicated that O 2 · can attack the bond between the carbon and chlorine atoms to form less chlorinated aromatic compounds.The aromatic compounds were further oxidized by O 2 · to generate aliphatic carboxylic acids which can be finally mineralized to CO 2 and H 2 O.Yang Li Junfeng Niu Lifeng Yin Wenlong Wang Yueping Bao Jing Chen Yanpei Duan 2011Journal of Environmental Sciences2011,23,11:9
17Biomimetic Corrugated Silicon Nanocone Arrays for Self-Cleaning Antireflection Coatings显示文摘Corrugated silicon nanocone(SiNC)arrays have been fabricated on a silicon wafer by two polystyrene-sphere-monolayer-masked etching steps in order to create high-performance antireflective coatings.The reflectance was reduced from above 35%to less than 0.7%in the range 400-1050 nm,and it remained below 0.5%at incidence angles up to 70°at 632.8 nm for both s-and p-polarized light.The fluorinated corrugated SiNC array surface exhibits superhydrophobic properties with a water contact angle of 164°.Yandong Wang Nan Lu Hongbo Xu Gang Shi Miaojun Xu Xiaowen Lin Haibo Li Wentao Wang Dianpeng Qi Yanqing Lu Lifeng Chi 2010Nano Research2010,3,7:8
18Laser direct writing and characterizations of flexible piezoresistive sensors with microstructures显示文摘Functional materials with high viscosity and solid materials have received more and more attentions in flexible pressure sensors,which are inadequate in the most used molding method.Herein,laser direct writing(LDW)method is proposed to fabricate flexible piezoresistive sensors with microstructures on PDMS/MWCNTs composites with an 8%MWCNTs mass fraction.By controlling laser energy,microstructures with different geometries can be obtained,which significantly impacts the performances of the sensors.Subsequently,curved microcones with excellent performance are fabricated under parameters of f=40 kHz and v=150 mm·s^(-1).The sensor exhibits continuous multi-linear sensitivity,ultrahigh original sensitivity of 21.80%kPa^(-1),wide detection range of over 20 kPa,response/recovery time of~100 ms and good cycle stability for more than 1000 times.Besides,obvious resistance variation can be observed when tiny pressure(a peanut of 30 Pa)is applied.Finally,the flexible piezoresistive sensor can be applied for LED brightness controlling,pulse detection and voice recognition.Chenying Zhang Wei Zhou Da Geng Cheng Bai Weida Li Songyue Chen Tao Luo Lifeng Qin Yu Xie 2021Opto-Electronic Advances2021,4,4:7
19Y-chromosome evidence for no independent origin of modern human in China显示文摘East Asia is one of the few regions in the world where a large number of human fossils have been unearthed. The continuity of hominid fossils in East Asia, particularly in China has been presented as strong evidence supporting an independent origin of modern humans in this area. To search for such evidence of a possible independent origin of modern humans in China, a total of 9988 male individuals were sampled across China. Three Y-chromosome biallelic markers (M89, M130 and YAP), which were located at the non-re-combinant region of Y-chromosome, were typed among the samples. Our result showed that all the individuals carry a mutation at one of the three loci. The three mutations (M89T, M130T, YAP+) coalesce to another mutation (M168T), which was originally derived from Africa about 31000 to 79000 years ago. In other words, all Y-chromosome samples from China, with no exception, were originally derived from a lineage of African origin. Hence, we conclude that even a very minor contribution of in situ hominid origin in China cannot be supported by the Y-chromosome evidence.KE Yuehai SU Bing LI Hongyu CHEN Lifeng QI Chunjian GUO Xinjun HUANG Wei JIN Jianzhong LU Daru JIN Li 2001Chinese Science Bulletin2001,46,11:7
20Evaporation of liquid fuel droplet at supercritical conditions显示文摘A comprehensive analysis of liquid fuel droplet evaporation at supercritical conditions is performed.The numerical model is based on complete time-dependent conservation equations,with a full account of variable thermophysical properties and vapor-liquid interfacial thermodynamics.And the model employs the Peng-Robinson(PR)equation of state(EOS).As a specific example,problems involving n-heptane droplet in nitrogen gas are investigated.The results indicate that the increase of ambient pressure and temperature results in the increase of surface temperature rise rate and surface regression rate.The transition from subcritical state to supercritical state can occur at the droplet surface when the droplet evaporates in a strongly supercritical environment.HE Peng LI YunQing ZHAO LiFeng 2011Science China(Technological Sciences)2011,54,2:7
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