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Search Results: 1 - 10 of 233378 matches for " Da-Li Chen "
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Analysis of kinetoplast cytochrome b gene of 16 Leishmania isolates from different foci of China: different species of Leishmania in China and their phylogenetic inference
Yang Bin-Bin,Chen Da-Li,Chen Jian-Ping,Liao Lin
Parasites & Vectors , 2013, DOI: 10.1186/1756-3305-6-32
Abstract: Background Leishmania species belong to the family Trypanosomatidae and cause leishmaniasis, a geographically widespread disease that infects humans and other vertebrates. This disease remains endemic in China. Due to the large geographic area and complex ecological environment, the taxonomic position and phylogenetic relationship of Chinese Leishmania isolates remain uncertain. A recent internal transcribed spacer 1 and cytochrome oxidase II phylogeny of Chinese Leishmania isolates has challenged some aspects of their traditional taxonomy as well as cladistics hypotheses of their phylogeny. The current study was designed to provide further disease background and sequence analysis. Methods We systematically analyzed 50 cytochrome b (cyt b) gene sequences of 19 isolates (16 from China, 3 from other countries) sequenced after polymerase chain reaction (PCR) using a special primer for cyt b as well as 31 sequences downloaded from GenBank. After alignment, the data were analyzed using the maximum parsimony, Bayesian and netwok methods. Results Sequences of six haplotypes representing 10 Chinese isolates formed a monophyletic group and clustered with Leishmania tarentolae. The isolates GS1, GS7, XJ771 of this study from China clustered with other isolates of Leishmania donovani complex. The isolate JS1 was a sister to Leishmania tropica, which represented an L. tropica complex instead of clustering with L. donovani complex or with the other 10 Chinese isolates. The isolates KXG-2 and GS-GER20 formed a monophyletic group with Leishmania turanica from central Asia. In the different phylogenetic trees, all of the Chinese isolates occurred in at least four groups regardless of geographic distribution. Conclusions The undescribed Leishmania species of China, which are clearly causative agents of canine leishmaniasis and human visceral leishmaniasis and are related to Sauroleishmania, may have evolved from a common ancestral parasite that came from the Americas and may have split off earlier than the other old world Leishmania. Our results also suggest the following: the isolates GS7, GS1 and XJ771 occur as part of the L. donovani complex; the JS1 isolate is L. tropica; and the isolate GS-GER20 identified as Leishmania gerbilli is close to KXG-2 which is L. turanica.
Prevalence of canine leishmaniasis in Beichuan County, Sichuan, China and phylogenetic evidence for an undescribed Leishmania sp. in China based on 7SL RNA
Ke Sun, Wang Guan, Jian-Guo Zhang, Ya-Jing Wang, Yu Tian, Lin Liao, Bin-Bin Yang, Da-Li Chen, Jian-Ping Chen
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-75
Abstract: In this study, rK39 dip-stick, ELISA and PCR methods were used to investigate the prevalence of canine leishmaniasis (CanL) in Beichuan County, Sichuan Province, China.Among the 86 dogs which were included in the study, 13 dogs were positive using the dip-stick test (15.12%), while 8 dogs were positive using ELISA (9.30%) and 19 dogs were positive for PCR (22.03%). In total, 32 dogs were positive for one or more tests (37.21%). Interestingly, phylogenetic analysis based on the partial 7SL RNA fragment provided evidence that an undescribed Leishmania species, which is clearly a causative agent of CanL and human visceral leishmaniasis, does exist in China. This result is consistent with our previous study.Our work confirmed that canine leishmaniasis is still prevalent in Beichuan County. Further control is urgently needed, as canine leishmaniasis is of great public health importance. The phylogenetic analysis based on 7SL RNA segment provides evidence for the existence of an undescribed Leishmania sp. in China.Leishmaniasis is a vector-borne disease caused by different species of the genus Leishmania, including subgenera Viannia and Leishmania. The diseases are characterized by a spectrum of clinical manifestations: cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL) and visceral leishmaniasis (VL) [1]. Globally, leishmaniasis affects 88 countries, which is an estimated 500,000 cases of VL and 1–1.5 million cases of CL each year [2]. Epidemiologically, canines are the major reservoirs of Leishmania, the etiological agent of human visceral leishmaniasis [3-7]. Following the accelerating urbanization and population mobility, canine leishmaniasis is epidemic in America, Asia and Europe [8-14].Leishmaniasis is still endemic in China, especially in the west and northwest regions. The prevalence of human leishmaniasis in west China was alarming according to the reports of Wang et al. [15] and Qu et al. [16]. Moreover, as our previous study [17,18] indicated, Lei
The Character of U(VI) Biosorption by Chlorella pyrenoidosa

LI Yue,XIE Shui-Bo,LIN Da-Li,SHI You,CHEN Ting,

微生物学通报 , 2008,
Abstract: 试验研究了小球藻吸附U(VI)的过程,探讨了吸附机理、吸附热力学和动力学.考查了pH值、时间、U(VI)的起始浓度和温度等对吸附的影响.研究表明,pH值对小球藻的吸附效果影响较大,小球藻吸附U(VI)的最佳pH值为6,最大吸附量为2.7mg/g,吸附在5min内基本达到平衡.小球藻对U(VI)的吸附量与其浓度的正相关;温度在20℃-30℃时,对铀的吸附影响不大.实验结果还表明,吸附过程符合准二级动力学方程,其相关系数达0.99,该吸附为多种反应同时作用的复杂过程.U(VI)在小球藻上的吸附行为可以很好地用Langmuir等温方程来描述.
Overexpression of RNF146 in Non-Small Cell Lung Cancer Enhances Proliferation and Invasion of Tumors through the Wnt/β-catenin Signaling Pathway
Ying Gao, Chengyang Song, Linping Hui, Chun-yu Li, Junying Wang, Ye Tian, Xu Han, Yong Chen, Da-Li Tian, Xueshan Qiu, Enhua Wang
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085377
Abstract: Studies have suggested a possible correlation between the newly identified E3 ubiquitin ligase ring finger protein 146 (RNF146) and tumor development. However, until now, studies on RNF146 have been restricted to poly(ADP-ribosyl)ation and ubiquitin ligation, whereas the role of RNF146 in tumor biology has rarely been reported. In the present study, the role of RNF146 in non-small cell lung cancer (NSCLC) was investigated. The results showed that the expression of RNF146 was increased in clinical lung cancer samples and cell lines. RNF146 expression correlated with tumor size, differentiation level, lymphatic metastasis, pTNM staging, and prognosis of patients in stage I. RNF146 expression was negatively correlated with Axin expression but positively correlated with the nuclear expression of β-catenin in NSCLC tissues. RNF146 downregulated the expression of Axin in lung cancer cell lines and induced the expression and nuclear distribution of β-catenin. Overexpression of RNF146 in NSCLC cell lines increased the levels of cyclinD1, cyclinE, and CDK4, promoted cell cycle G0/G1-S transitions, and regulated cell proliferation. Overexpression of RNF146 led to upregulated levels of matrix metalloproteinases 2 and 7 and enhanced lung cancer cell invasiveness, events that were mediated by the classical Wnt/β-catenin signaling pathway. In summary, the data in the present study indicate that RNF146 regulated the development and progression of NSCLC by enhancing cell growth, invasion, and survival, suggesting that RNF146 may be a potential treatment target in NSCLC.
Preparation and Characterization of Porous Apatite-Wollastonite/β-Tricalcium Phosphate Composite Scaffolds

XIAO Bin,ZHOU Da-Li,YANG Wei-Zhong,OU Jun,TANG Yan-Juan,CHEN Huai-Qing,

无机材料学报 , 2006,
Abstract: 以磷灰石-硅灰石玻璃陶瓷(AW)粉和β-磷酸三钙(β-TCP)粉为原料.以硬脂酸为致孔剂.经模压成型、1170℃烧结制备磷灰石-硅灰石/β-磷酸三钙复合多孔支架材料(AW/β-TCP).采用X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、诱导耦合等离子体原子发射光谱(ICP-AES)等方法分析支架的晶相组成、显微结构、物理性能、生物活性和降解性.将大鼠骨髓间充质干细胞(rMSCs)与支架体外复合培养评价支架的生物相容性.结果表明:所制备的AW/β-TCP支架材料的抗压强度达14.3MPa.孔隙率达66.9%.孔径为100-700μm.具有良好的生物相容性、生物活性和降解性.可作为骨组织工程支架的候选材料.
Robust fuzzy adaptive control of manipulators based on the generalized hyperbolic model

GAO Dao-xiang,XUE Ding-yv,CHEN Da-li,DU Tian-rong,

控制理论与应用 , 2007,
Abstract: Taking advantage of the property of the generalized hyperbolic model:a universal approximator,a fuzzy adaptive controller is proposed for the trajectory tracking control of robotic manipulator.Firstly,by translating the input variables,a generalized hyperbolic model can approximate to any uncertain dynamics by an arbitrary accuracy.For the external disturbances and the approximation errors,a linear matrix inequality(LMI) problem is then solved to guarantee the robustness of the closed-loop.Being different from the traditional fuzzy-based function,the hyperbolic model uses fewer updated parameters to guarantee a satisfactory tracking performance.Finally,numerical simulations are carried out to show the expected robustness and tracking accuracy.
Characteristics of β-Tricalcium Phosphate/Poly (L-lactic acid) Composite Combining with Rat Periosteum Derived Osteoblast

ZHOU Da-Li,YANG Wei-Zhong,YIN Guang-Fu,ZHENG Chang-Qiong,CHEN Rui,CHEN Huai-Qing,

无机材料学报 , 2005,
Abstract: 采用溶液浇铸-模压成型-沥滤方法制备了β-TCP/PLLA多孔支架材料,将支架材料与大鼠骨膜成骨细胞复合获得新型组织工程骨修复材料.通过抗压强度及压缩模量的表征研究了支架材料的力学性能;采用SEM观测、MTT法、碱性磷酸酶活性及骨钙素分泌量检测细胞复合材料的体外成骨特性;通过裸鼠肌袋种植,以组织学方法评价细胞复合材料的异位成骨能力.结果表明:β-TCP/PLLA多孔支架材料孔隙率可调,孔径为100~200μm,孔道相互贯通;材料抗压强度和压缩模量随孔隙率的增大而降低,β-TCP复合PLLA后材料的力学性能高于同孔隙率的纯PLLA多孔材料;复合支架材料适宜骨膜成骨细胞粘附和生长,无细胞毒性;骨膜成骨细胞复合β-TCP/PLLA支架材料的体外成骨特性良好,且具有体内异位成骨能力.
SNP analysis of the fragments of three functional genes of the mushroom Lentinula edodes

WANG Da-Li,ZHANG Jin-Xi,BIAN Yin-Bing,CHEN Qiang,HUANG Chen-Yang,

菌物学报 , 2013,
Abstract: 以15个香菇栽培品种为材料,对尿嘧啶核苷酸-胞嘧啶核苷酸激酶基因(UMP-CMP kinase gene,uck1)、分裂原活化蛋白激酶基因(mitogen-activated protein kinase gene,mapk)和外切β-1,3葡聚糖酶基因(exo-β-1,3-glucanase-encoding gene,exg1)进行了部分序列的单核苷酸多态性(single nucleotide polymorphism,SNP)分析。结果表明,测序中出现的双峰,是菌丝双核体细胞中两细胞核之间的差异造成的。在采用uck1、mapk和exg1的3,126bp中,共发现48处多态性位点,发生频率为1/65bp,其中36个属于转换、12个为颠换。从群体发生频率上,38个属于超过10%的常见SNP,10个属于罕见SNP。不同基因的SNP发生频率不同,uck1、mapk和exg1的SNP发生频率分别为1.40%、0.82%和2.41%。外显子区SNP数量高于内含子,3个基因在外显子区域分布28个,内含子分布20个。外显子的28个SNP位点中,11个为错义突变,17个为同义突变。错义突变引起了编码氨基酸的改变。对SNP位点的聚类分析表明,15个栽培品种间存在的多态性位点在1–36之间,15个品种的SNP类型不同。uck1,mapk,exg1的SNP可用于香菇栽培品种的鉴别。
Epidemiological study on periodontal health status of medical students

LI Chao-lun
, LIU Da-li, XIE Yu-feng, SONG Zhong-chen, GE Lin-hua, SHU Rong

- , 2017, DOI: 10.3969/j.issn.1674-8115.2017.04.025
Abstract: 目的 ·对医学院学生口腔健康知识和行为及其与牙周健康状态的关系进行调查和分析,研判该人群的整体牙周健康水平。 方法 · 602名的医学院学生被随机纳入横断面流行病学调查。调查问卷内容包括社会人口学信息、牙周健康相关行为、牙周健康相关知识、自我感觉和父母牙周情况等。同时对受试者指数牙的各项牙周指数进行检测,包括探诊深度、临床附着丧失和探诊出血等。 结果 · 570名受试者(16~26岁)完成了全部调查。受试者中,从未使用过牙线者占79.82%;从未接受过牙周洁治者占78.25%。50.25%的指数牙存在探诊出血,仅0.70%的受试者未检出探诊出血,81.05%的受试者被检出存在一定程度的牙周附着丧失。与女生比较,男生更加易患罹患牙周炎(P=0.027)和牙龈炎 (P=0.012)。 结论 ·未发现可能影响牙周健康的新风险因素。常规的牙周洁治和口腔卫生维护是年轻人群预防牙周炎的重要方法。
: Objective · To investigate and analyze periodontal health knowledge and behaviors in medical students and the relationship of these knowledge and behaviors with periodontal health status, and to determine the periodontal health level of this population. Methods · A total of 602 medical students were included in this cross-sectional epidemiological study. The questionnaire covered sociodemographic information, periodontal health-related behaviors and knowledge, experience about themselves, and periodontal health of parents, etc. Meanwhile, periodontal health indices of index teeth were examined, including probing depth (PD), clinical attachment loss (CAL), and bleeding on probing (BOP), etc. Results · Of 570 subjects aged 16-26 who completed the survey, 79.82% never used dental floss, and 78.25% never underwent periodontal debridement. 50.25% of the index teeth had BOP, and only 0.70% of the subjects had no BOP. 81.05% of the subjects had some degree of periodontal attachment loss. Male students were more susceptible to periodontitis (P=0.027) and gingivitis (P=0.012) than female students. Conclusion · No new risk factors affecting the periodontal health are identified. Regular periodontal cleaning and protection are important for young people to prevent periodontitis
Impact of elevated O3 on eco-physiology of trees

XU Sheng,HE Xing-Yuan,CHEN Wei,TAO Da-Li,XU Wen-Duo,

生态学报 , 2009,
Abstract: Ozone (O3) is considered one of the important air pollutants in the present world. With the development of urbanization and the continuous increasing of atmospheric O3 concentration, more and more attention is focused on the impact of elevated O3 on plant. The impact of elevated O3 on trees is quite complicated. Based on the results of our experiments on the relationship between the trees and climate change in recent years, and related literature investigation, we will review the research advances in the impact of elevated O3 on eco-physiology of trees, such as the O3-induced visible injury, the impact of O3 on the growth and morphological structure, photosynthesis, nutrition metabolism, antioxidant system of trees and the impact of O3 in combination with other environmental factors, such as temperature, drought and elevated CO2. We hope these will provide a scientific reference for the further research on the impact of O3 on trees, especially on the sustainable forest management and the selection of urban tree species in respect to the increased atmosphere O3 concentration under the global climate change.
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