期刊文献+
共找到1,818篇文章
< 1 2 91 >
每页显示 20 50 100
Advances of supercritical fluid chromatography in lipid profiling 预览
1
作者 Yang Yang Yanshan Liang +3 位作者 Jina Yang Fengying Ye Ting Zhou Gongke Li 《药物分析学报:英文版》 CAS CSCD 2019年第1期1-8,共8页
Supercritical fluid chromatography (SFC) meets with great favor due to its high efficiency, low organic solvent consumption, and the specialty for the identification of the isomeric species. This review describes the ... Supercritical fluid chromatography (SFC) meets with great favor due to its high efficiency, low organic solvent consumption, and the specialty for the identification of the isomeric species. This review describes the advances of SFC in targeted and untargeted lipid profiling. The advancement of the SFC instruments and the stationary phases are summarized. Typical applications of SFC to the targeted and untargeted lipid profiling are discussed in detail. Moreover, the perspectives of SFC in the lipid profiling are also proposed. As a useful and promising tool for investigating lipids in vitro and in vivo, SFC will predictably obtain further development. 展开更多
关键词 SUPERCRITICAL fluid chromatography Online SFC technique Untargeted LIPID PROFILING TARGETED LIPID PROFILING LIPIDOMICS
在线阅读 下载PDF
Comparative analysis of C-type lectin domain proteins in the ghost moth, Thitarodes xiaojinensis (Lepidoptera: Hepialidae)
2
作者 Qian Meng Ji-Hong Zhang +5 位作者 Huan Zhang Gui-Ling Zhou Ruo-Yao Ni Yan-Ni Zhao Qi-Lian Qin Zhen Zou 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第3期453-465,共13页
Insects have a large family of C-type lectins involved in cell adhesion, pathogen recognition and activation of immune responses. In this study, 32 transcripts encoding C-type lectin domain proteins (CTLDPs) were iden... Insects have a large family of C-type lectins involved in cell adhesion, pathogen recognition and activation of immune responses. In this study, 32 transcripts encoding C-type lectin domain proteins (CTLDPs) were identified from the Thitarodes xiaojinensis transcriptome. According to their domain structures, six CTLDPs with one carbohydraterecognition domain (CRD) were classified into the CTL-S subfamily. The other 23 CTLDPs with two CRDs were grouped into the immulectin (IML) subfamily. The remaining three with extra regulatory domains were sorted into the CTL-X subfamily. Phylogenetic analysis showed that CTL-S and CTL-X members from different insects could form orthologous groups. In contrast, no T. xiaojinensis IML orthologues were found in other insects. Remarkable lineage-specific expansion in this subfamily was observed reflecting that these CTLDPs, as important receptors, have evolved diversified members in response to a variety of microbes. Prediction of binding ligands revealed that T. xiaojinensis, a coldadapted species, conserved the ability of CRDs to combine with Ca^2+ to keep its receptors from freezing. Comparative analysis of induction of CTLDP genes after different immune challenges indicated that IMLs might play critical roles in immune defenses. This study examined T. xiaojinensis CTLDPs and provides a basis for further studies of their characteristics. 展开更多
关键词 binding ligand carbohydrate-recognition DOMAIN C-type LECTIN DOMAIN protein expression PROFILING PHYLOGENETIC feature Thitarodes xiaojinensis
Impurity profile of macitentan in tablet dosage form using a stability-indicating high performance liquid chromatography method and forced degradation study 预览
3
作者 Narasimha S LAKKA Chandrasekar KUPPAN Parthasarathy RANGASAMY 《色谱》 CAS CSCD 北大核心 2019年第1期100-110,共11页
Macitentan(MAC)is a pulmonary arterial hypertension(PAH)drug marketed as a tablet and often has stability issues in the final dosage form.Quantitative determination of MAC and its associated impurities in tablet dosag... Macitentan(MAC)is a pulmonary arterial hypertension(PAH)drug marketed as a tablet and often has stability issues in the final dosage form.Quantitative determination of MAC and its associated impurities in tablet dosage form has not been previously reported.This study quantified impurities present in Macitentan tablets using a binary solvent-based gradient elution method using reversed phase-high performance liquid chromatography.The developed method was validated per International Conference on Harmonization(ICH)guidelines and the drug product was subjected to forced degradation studies to evaluate stability.The developed method efficiently separated the drug and impurities(48 min)without interference from solvents,excipients,or other impurities.The developed method met all guidelines in all characteristics with recoveries ranging from 85%-115%,linearity with r^2≥0.996 6,and substantial robustness.The stability-indicating nature of the method was evaluated using stressed conditions(hydrolysis:1 N HCl at 80℃/15min;1 N NaOH at 25℃/45min;humidity stress(90%relative humidity)at 25℃for 24h,oxidation:at 6%(v/v)H2O2,80℃/15min,thermolysis:at 105℃/16h and photolysis:UV light at 200Wh/m^2;Fluorescent light at 1.2 million luxh).Forced degradation experiments showed that the developed method was effective for impurity profiling.All stressed samples were assayed and mass balance was>96%.Forced degradation results indicated that MAC tablets were sensitive to hydrolysis(acid and alkali)and thermal conditions.The developed method is suitable for both assay and impurity determination,which is applicable to the pharmaceutical industry. 展开更多
关键词 reverse phase-high performance liquid chromatography(RP-HPLC) STABILITY-INDICATING METHOD forced degradation STUDY binary solvent gradient ENDOTHELIN receptor antagonist(ERA) pulmonary arterial hypertension(PAH) macitentan(MAC) IMPURITY profiling
在线阅读 下载PDF
非现实位移事件的编码与突显 预览
4
作者 张克定 《外国语文》 北大核心 2019年第1期1-7,共7页
非现实位移事件是认知主体运用认知想象能力将不可动实体构想为可动实体,使其在心理上和视觉上发生了相对于参照实体的位置变化的一种位移事件。认知主体不仅能够将静态的方位事件构想为动态的非现实位移事件,而且能够运用语言对其进行... 非现实位移事件是认知主体运用认知想象能力将不可动实体构想为可动实体,使其在心理上和视觉上发生了相对于参照实体的位置变化的一种位移事件。认知主体不仅能够将静态的方位事件构想为动态的非现实位移事件,而且能够运用语言对其进行编码。英语对非现实位移事件的编码必须包括位移事件的所有四个要素:位移主体、参照实体、位移和路径,缺一不可。在对非现实位移事件中的'起点-路径-终点'意象图式进行编码时,认知主体既可以选择使用最大窗口化,也可以选择使用部分窗口化,前者突显位移主体与全路径之间的动态空间关系,后者突显位移主体与部分路径(即起点或终点)之间的动态空间关系。 展开更多
关键词 非现实位移事件 编码 突显 “起点-路径-终点”意象图式 路径
在线阅读 免费下载
城铁车辆铝合金车体底架钻孔装置的结构设计 预览
5
作者 李卫 郭雪艳 《现代机械》 2019年第1期40-42,共3页
目前,城铁车辆铝合金车体底架的钻孔工作需采用大型龙门五轴加工中心及90°角度头进行加工,设备占用时间长,直角铣头易磨损,生产成本投入高。根据底架的结构特点及安装使用要求,设计了一款具有较强通用性的钻孔装置。该装置采用滚... 目前,城铁车辆铝合金车体底架的钻孔工作需采用大型龙门五轴加工中心及90°角度头进行加工,设备占用时间长,直角铣头易磨损,生产成本投入高。根据底架的结构特点及安装使用要求,设计了一款具有较强通用性的钻孔装置。该装置采用滚动直线导轨副,可实现钻孔装置精准地往复直线运动;通过计算合理的配重比,可实现多方位的钻孔工作;通过改变磁力钻传统的使用方式并结合靠模的使用,确保磁力钻精准定位。该装置的研发能够提高铝合金车体底架钻孔的工作效率、降低钻孔成本,在城铁车辆底架的制造过程中具有广泛的应用潜力。 展开更多
关键词 铝合金车体底架 滚动直线导轨副 磁力钻 配重比 靠模
在线阅读 下载PDF
Intracellular effects of prodrug-like wortmannin probes
6
作者 Shasha Ying Shubo Du +5 位作者 Jia Dong Bi Xuan Ng Chengwu Zhang Lin Li Jingyan Ge Qing Zhu 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第1期67-70,共4页
Wortmannin, a known inhibitor of phosphoinositide 3-kinases(PI3 Ks), their low selectivity and high toxicity is still problematic and less is known about their effects on PI3 Ks in cellular systems. Hence, we have syn... Wortmannin, a known inhibitor of phosphoinositide 3-kinases(PI3 Ks), their low selectivity and high toxicity is still problematic and less is known about their effects on PI3 Ks in cellular systems. Hence, we have synthesized a series of multifunctional wortmannin probes with the ability to self-activate, by installing a clickable handle at C11 site, and secondary amine and cancer-targeting moiety at C20 site respectively. MTT assay first confirmed that self-activating probes have better inhibition potency and biotin enhanced their cancer cell uptake. Further experiments showed most of probes can target PI3 K/Akt/mTOR pathway with prolonged turn-over time. Protein profiling and pull-down results were observed that the derivatives not only labelled four PI3 Ks with selectivity, but also engaged in covalent interactions with numerous cellular proteins which could be the major reason of their high toxicity. 展开更多
关键词 WORTMANNIN P3IK Activity-based probe PROFILING Cancer-targeting Self-activating
涂装机器人仿形规划与车身外观工艺调试 预览
7
作者 李欣 邬波 易炜 《汽车实用技术》 2019年第5期158-161,共4页
喷涂机器人已经在汽车工业中得到广泛应用,而喷涂轨迹是保证喷涂质量的重要因素。文章对机器人喷涂轨迹做详细阐述,并对该轨迹的编制流程进行全面分析,对每个环节进行重点论述,并结合整车外观调试工艺流程,对影响外观质量的因素加以说明。
关键词 涂装 仿形 轨迹 机器人 外观
在线阅读 下载PDF
涂装喷漆机器人仿形离线编程仿真技术应用探究
8
作者 王泽龙 《现代涂料与涂装》 CAS 2019年第2期34-37,40共5页
综合考虑了机器人的布局、涂料性能、设备运行、生产节拍及机器人上漆率,并结合各离线编程软件应用过程中的经验,归纳总结了涂装喷漆机器人仿形离线仿真的主要工作并进行了论述,主要工作包括机器人的工作分配、机器人的轨迹规划、离线... 综合考虑了机器人的布局、涂料性能、设备运行、生产节拍及机器人上漆率,并结合各离线编程软件应用过程中的经验,归纳总结了涂装喷漆机器人仿形离线仿真的主要工作并进行了论述,主要工作包括机器人的工作分配、机器人的轨迹规划、离线环境中车身位置的确定、起喷位置设置、等待距离设置、刷子设置及仿真验证等。 展开更多
关键词 喷漆 机器人 仿形 离线编程 仿真
Physiological and genome-wide gene expression analyses of cold-induced leaf rolling at the seedling stage in rice (Oryza sativa L.) 预览
9
作者 Jingfang Dong Junliang Zhao +6 位作者 Shaohong Zhang Tifeng Yang Qing Liu Xingxue Mao Hua Fu Wu Yang Bin Liu 《作物学报:英文版》 CAS CSCD 2019年第4期431-443,共13页
Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanism... Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanisms underlying these two traits remains unknown. In the present study, a cold-tolerant rice cultivar, Lijiangxintuanheigu, and a cold-sensitive cultivar, Sanhuangzhan-2, were subjected to low-temperature treatments and physiolog-ical and genome-wide gene expression analyses were conducted. Leaf rolling occurred at temperatures lower than 11℃, whereas discoloration appeared at moderately low temperatures such as 13℃. Chlorophyll contents in both cultivars were significantly decreased at 13℃, but not altered at 11℃. In contrast, the relative water content and relative electrolyte leakage of both cultivars decreased significantly at 11℃, but did not change at 13℃. Expression of genes associated with calcium signaling and abscisic acid (ABA) degradation was significantly altered at 11℃ in comparison with 25℃ and 13℃. Numerous genes in the DREB, MYB, bZIP, NAC, Zinc finger, bHLH, and WRKY gene families were differentially expressed. Many aquaporin genes and the key genes in trehalose and starch synthesis were down regulated at 11℃ in comparison with 25℃ and 13℃. These results suggest that the two chilling injury symptoms are temperature-specific and are controlled by different mechanisms. Cold-induced leaf rolling is associated with calcium and ABA signaling pathways and is regulated by multiple transcriptional regulators. The suppression of aquaporin genes and reduced accumulation of soluble sugars under cold stress results in a reduction in cellular water potential and consequently leaf rolling. 展开更多
关键词 Rice(Oryza sativa L.) Cold-induced LEAF yellowing Cold-induced LEAF rolling PHYSIOLOGICAL analysis GENOME-WIDE expression profiling
在线阅读 免费下载
方盒形件侧壁环形凹筋仿形增量成形
10
作者 楚智虎 《模具工业》 2019年第2期20-22,共3页
为了加强薄板空心零件的刚度,提高其整体承载能力,需要在不同的部位成形外凸或内凹的筋,圆筒形零件的筒壁成形环形筋,工艺容易实现,但在方盒形件的侧壁成形连续的环形筋时,由于有4个转角,压筋工艺的实现难度较大。经过分析比较了几种成... 为了加强薄板空心零件的刚度,提高其整体承载能力,需要在不同的部位成形外凸或内凹的筋,圆筒形零件的筒壁成形环形筋,工艺容易实现,但在方盒形件的侧壁成形连续的环形筋时,由于有4个转角,压筋工艺的实现难度较大。经过分析比较了几种成形工艺方案,提出了仿形增量成形方法,成功应用于面包片烤炉机主壳的成形中,提高了零件成形质量,取得了良好的效果。 展开更多
关键词 盒形件 环形凹筋 仿形 增量成形 活动模芯
UP-TreeRec:Building Dynamic User Profiles Tree for News Recommendation 预览
11
作者 Ming He Xiaofei Wu +1 位作者 Jiuling Zhang Ruihai Dong 《中国通信:英文版》 SCIE CSCD 2019年第4期219-233,共15页
Online news recommendation systems aim to address the information explosion of news and make personalized recommendations for users.The key problem of personalized news recommendation is to model users’interests and ... Online news recommendation systems aim to address the information explosion of news and make personalized recommendations for users.The key problem of personalized news recommendation is to model users’interests and track their changes.A common way to deal with the user modeling problem is to build user profiles from observed behavior.However,the majority of existing methods make static representations of user profiles and little research has focused on effective user modeling that could dynamically capture user interests in news topics.To address this problem,in this paper,we propose UP-TreeRec,a news recommendation framework based on a user profile tree(UP-Tree),which is a novel framework combining content-based and collaborative filtering techniques.First,by exploiting a novel topic model namely UILDA,we obtain the representation vectors for news content in a topic space as the fundamental bridge to associate user interests with news topics.Next,we design a decision tree with a dynamically changeable structure to construct a user interest profile from the user’s feedback.Furthermore,we present a clustering-based multidimensional similarity computation method to select the nearest neighbor of the UP-Tree efficiently.We also provide a Map-Reduce framework-based implementation that enables scaling our solution to real-world news recommendation problems.We conducted several experiments compared to the state-of-the-art approaches on real-world datasets and the experimental results demonstrate that our approach significantly improves accuracy and effectiveness in news recommendation. 展开更多
关键词 NEWS RECOMMENDATION user PROFILING CONTENT-BASED RECOMMENDATION COLLABORATIVE filtering
在线阅读 下载PDF
Cell-Type Identification in the Autonomic Nervous System
12
作者 Di-Shi Liu Tian-Le Xu 《神经科学通报:英文版》 SCIE CAS CSCD 2019年第1期145-155,共11页
The autonomic nervous system controls various internal organs and executes crucial functions through sophisticated neural connectivity and circuits. Its dysfunction causes an imbalance of homeostasis and numerous huma... The autonomic nervous system controls various internal organs and executes crucial functions through sophisticated neural connectivity and circuits. Its dysfunction causes an imbalance of homeostasis and numerous human disorders. In the past decades, great efforts have been made to study the structure and functions of this system, but so far, our understanding of the classification of autonomic neuronal subpopulations remains limited and a precise map of their connectivity has not been achieved.One of the major challenges that hinder rapid progress in these areas is the complexity and heterogeneity of autonomic neurons. To facilitate the identification of neuronal subgroups in the autonomic nervous system, here we review the well-established and cutting-edge technologies that are frequently used in peripheral neuronal tracing and profiling, and discuss their operating mechanisms, advantages, and targeted applications. 展开更多
关键词 AUTONOMIC nervous system NEURONAL TRACING Genetic MARKER Molecular PROFILING CELL-TYPE diversity
Community structure, dispersal ability and functional profiling of microbiome existing in fat body and ovary of the brown planthopper, Nilaparvata lugens
13
作者 Jian-Hua Zhang Na Yu +1 位作者 Xi-Xia Xu Ze-Wen Liu 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第4期683-694,共12页
The endosymbionts play vital roles in growth, development and reproduction in insects. Yeast-like endosymbionts (YLSs) have been well studied in Nilaparvata lugens (N. lugens), but little is known about the tissue-spe... The endosymbionts play vital roles in growth, development and reproduction in insects. Yeast-like endosymbionts (YLSs) have been well studied in Nilaparvata lugens (N. lugens), but little is known about the tissue-specific bacterial microbiomes, especially on the microbial intersection among internal tissues. Here, the correlation of microbial composition, structure, dispersal ability and functional profiling were illuminated in two tissues, the fat body and ovary in N. lugens. A total of 11 phyla and 105 genera were captured from all samples;Firmicutes and Proteobacteria were the most predominant and accounted for more than 99% in all samples. However, the relative abundance ofFirmicutes and Proteobacteria was significantly different in ovary and fat body through Fisher's Least Significant Difference test. Microbial diversity but not the richness index in the two tissues exhibited significant difference. Furthermore, the microbial community structure of the ovary and fat body were primarily determined by tissue quality. Firmicutes showed strong dispersal ability between ovary and fat body based on the quantitative null model assessing, indicating the frequent interaction of these microbiomes in the two tissues. In addition, the Kyoto Encyclopedia of Genes and Genomes pathways of microbial participation were delineated. The ten most abundant pathways counted for over 46% of the annotation and were shared between the two tissues, mainly containing Energy Metabolism and Amino Acid Metabolism/Biosynthesis. The results will provide insights into the correlation of microbial community structure between ovary and fat body of N. lugens. 展开更多
关键词 dispersal ability fat body FUNCTIONAL PROFILING microbial structure NILAPARVATA LUGENS OVARY
某型燃机护罩国产化制造技术 预览
14
作者 肖宏 文仲波 +2 位作者 董军 余勇 杨东 《装备制造与教育》 2019年第1期14-17,共4页
我国的重型燃气轮机研发和制造水平相对滞后,某型燃机长期只能从日本、美国等国采购,为减少采购成本,拓展自主化产品线,大幅提高自主罩壳产品合格率,是目前燃机机组国产化的必然趋势。本文通过对某型燃机护罩国产自主化制造技术进行详... 我国的重型燃气轮机研发和制造水平相对滞后,某型燃机长期只能从日本、美国等国采购,为减少采购成本,拓展自主化产品线,大幅提高自主罩壳产品合格率,是目前燃机机组国产化的必然趋势。本文通过对某型燃机护罩国产自主化制造技术进行详细介绍,重点对燃机排气缸切向支柱护罩的结构形式、型线种类、材质特性等发面进行分析、建立压型方案、焊接技术试验,并成功实施燃机护罩生产制造,为同类型产品制造积累相关经验。 展开更多
关键词 燃机护罩 马氏体不锈钢 压型 焊接
在线阅读 下载PDF
基于嵌入式单片机的仿形玉米播种机设计研究 预览
15
作者 段永彬 张文灼 +1 位作者 徐双杰 高清海 《农机化研究》 北大核心 2019年第12期92-97,共6页
国内外玉米播种机在排种、施肥的驱动方面多采用机械传动,在调整株距和施肥量方面为有级调速且精度较差。为此,设计了玉米播种机嵌入式单片机控制系统,可测定机组实际作业速度以控制株距和施肥量。控制系统由地轮与GPS的比较测速系统、... 国内外玉米播种机在排种、施肥的驱动方面多采用机械传动,在调整株距和施肥量方面为有级调速且精度较差。为此,设计了玉米播种机嵌入式单片机控制系统,可测定机组实际作业速度以控制株距和施肥量。控制系统由地轮与GPS的比较测速系统、主控单元、驱动单元、带反馈的播种与施肥电机等组成。其中,比较测速系统使播种株距更加均匀,驱动采用PWM信号及PID算法,电机跟随性良好;整体采用模块化设计,便于播种机单体的扩展。田间试验表明:播种的株距均匀度优于机械式播种机,设定株距为25cm时,株距合格率达100%,没有重播和漏播,最大偏差为7 cm,施肥量精度高于传统手工调节的方式,施肥偏差低于4%,有很大的推广价值。 展开更多
关键词 玉米播种机 仿形 嵌入式单片机
在线阅读 下载PDF
基于多场景FSDB向量解析提高电源完整性分析覆盖率 预览
16
作者 徐慧敏 朱薇薇 施建安 《电子技术应用》 2018年第8期10-12,共3页
超高晶体管密度和不断增加的工作频率导致更严重的电源完整性问题,基于FSDB的门级向量进行仿真可实现更精确的分析结果。FSDB持续时间太长,在整个仿真周期内分析全芯片电源完整性是不切实际的,需解析其中实际案例覆盖率最高的时间段。... 超高晶体管密度和不断增加的工作频率导致更严重的电源完整性问题,基于FSDB的门级向量进行仿真可实现更精确的分析结果。FSDB持续时间太长,在整个仿真周期内分析全芯片电源完整性是不切实际的,需解析其中实际案例覆盖率最高的时间段。本文所述方法基于电源完整性相关特征,通过多场景FSDB向量解析,提高IRDrop和Power EM违例覆盖率,实现更全面的电源完整性分析方案。 展开更多
关键词 电源完整性 FSDB 向量解析 IR-Drop PowerEM
在线阅读 下载PDF
Profiling the Change of Key Chemical Ingredients in Combination of Aconitum carmichaeli Debx. and Bletilla striata (Thunb.) Reichb.f. by UPLC-QTOF/MS with Multivariate Statistical Analysis 预览
17
作者 王超 王宇光 高月 《世界中西医结合杂志(英文)》 2018年第3期48-55,共8页
In the present study, an ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) based chemical profiling approach to rapidly evaluate chemical diversity after c... In the present study, an ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) based chemical profiling approach to rapidly evaluate chemical diversity after codecocting of the combination of Aconitum carmichaeli Debx.(wu-tou in Chinese, WT) and Bletilla striata (Thunb.) Reichb.f.(bai-ji in Chinese, BJ) incompatible pair. Two different kinds of decoctions, namely WT-BJ mixed decoction: mixed water extract of each individual herbs, and WT-BJ co-decoction: water extract of mixed two constituent herbs, were prepared. Batches of these two kinds of decoction samples were subjected to UPLC-QTOF/MS analysis, the datasets of tR-m/z pairs, ion intensities and sample codes were processed with supervised orthogonal partial least squared discriminant analysis (OPLS-DA) to holistically compare the difference between these two kinds of decoction samples. Once a clear classification trend was found in score plot, extended statistical analysis was performed to generate S-plot, in which the variables (tR-m/z pair) contributing most to the difference were clearly depicted as points at the two ends of "S", and the components that correlate to these ions were regarded as the most changed components during co-decocting of the incompatible pair. The identities of the changed components can be identified by comparing the retention times and mass spectra with those of reference compounds and/or tentatively assigned by matching empirical molecular formulae with those of the known compounds published in the literatures. Using the proposed approach, global chemical difference was found between mixed decoction and co-decoction, and hypaconitine, mesaconitine, deoxyaconitine, aconitine, 10-OH-mesaconitine, 10-OH-aconitine and deoxyhypaconitine were identified as the most changed toxic components of the combination of WT-BJ incompatible pair during co-decocting. It is suggested that this newly established approach could be used to practically reveal the possible toxic components change 展开更多
关键词 Eighteen INCOMPATIBLE MEDICATIONS (Shi Ba Fan) UPLC-QTOF/MS ACONITUM carmichaeli Debx.(Wutou) Bletilla striata (Thunb.) Reichb.f.(Baiji) Complex sample PROFILING Multivariate statistical analysis
在线阅读 下载PDF
Gut microbiome profiling and colorectal cancer in African Americans and Caucasian Americans 预览
18
作者 Lulu Farhana Fadi Antaki +6 位作者 Farhan Murshed Hamidah Mahmud Stephanie L Judd Pratima Nangia-Makker Edi Levi Yingjie Yu Adhip PN Majumdar 《世界胃肠病理生理学杂志:英文版(电子版)》 2018年第2期47-58,共12页
AIM To determine whether and to what extent the gut microbiome is involved in regulating racial disparity in colorectal cancer(CRC).METHODS All patients were recruited and experiments were performed in accordance with... AIM To determine whether and to what extent the gut microbiome is involved in regulating racial disparity in colorectal cancer(CRC).METHODS All patients were recruited and experiments were performed in accordance with the relevant guidelines and regulations by the Institutional Review Boards(IRB),committees of the John D.Dingell VAMC and Wayne State University guidelines.African American(AA)and Caucasian American(CA)patients were scheduled for an outpatient screening for colonoscopy,and no active malignancy volunteer patients were doubly consented,initially by the gastroenterologist and later by the study coordinator,for participation in the study.The gut microbial communities in colonic effluents from AAs and CAs were examined using 16sRNA profiling,and bacterial identifications were validated by performing SYBR-based Real Time PCR.For metagenomic analysis to characterize the microbial communities,multiple software/tools were used,including Metastats and R statistical software.RESULTS It is generally accepted that the incidence and mortality of CRC is higher in AAs than in CAs.However,the reason for this disparity is not well understood.We hypothesize that the gut microbiome plays a role in regulating this disparity.Indeed,we found significant differences in species richness and diversity between AAs and CAs.Bacteroidetes was more abundant in AAs than in CAs.In particular,the pro-inflammatory bacteria Fusobacterium nucleatum and Enterobacter species were significantly higher in AAs,whereas probiotic Akkermansia muciniphila and Bifidobacterium were higher in CAs.The polyphyletic Clostridia class showed a divergent pattern,with Clostridium XI elevated in AAs,and Clostridium IV,known for its beneficial function,higher in CAs.Lastly,the AA group had decreased microbial diversity overall in comparison to the CA group.In summary,there were significant differences in pro-inflammatory bacteria and microbial diversity between AA and CA,which may help explain the CRC disparity between groups.CONCLUSION Our current investi 展开更多
关键词 Human GUT MICROBIOME Colorectal cancer FUSOBACTERIUM nucleatum African AMERICANS 16S RNA PROFILING METAGENOMICS
在线阅读 免费下载
Prediction of Potential Disease-Associated MicroRNAs Based on Hidden Conditional Random Field 预览
19
作者 Maozu Guo Shuang Cheng +2 位作者 Chunyu Wang Xiaoyan Liu Yang Liu 《哈尔滨工业大学学报:英文版》 EI CAS 2018年第1期57-66,共10页
MicroRNAs ( miRNAs) are reported to be associated with various diseases. The identification of disease-related miRNAs would be beneficial to the disease diagnosis and prognosis. However, in contrast with the widely av... MicroRNAs ( miRNAs) are reported to be associated with various diseases. The identification of disease-related miRNAs would be beneficial to the disease diagnosis and prognosis. However, in contrast with the widely available expression profiling, the limited knowledge of molecular function restrict the development of previous methods based on network similarity measure. To construct reliable training data, the decision fusion method is used to prioritize the results of existing methods. After that, the performance of decision fusion method is validated. Furthermore, in consideration of the long range dependencies of successive expression values, Hidden Conditional Random Field model ( HCRF) is selected and applied to miRNA expression profiling to infer disease-associated miRNAs. The results show that HCRF achieves superior performance and outperforms the previous methods. The results also demonstrate the power of using expression profiling for discovering disease-associated miRNAs. 展开更多
关键词 expression PROFILING hidden CONDITIONAL RANDOM field miRNA-disease ASSOCIATION network
在线阅读 免费下载
红花丝采收机扶禾器升降装置设计及仿真分析 预览 被引量:1
20
作者 古乐乐 曹卫彬 +3 位作者 孙胃岭 刘姣娣 田东洋 麻平 《农机化研究》 北大核心 2018年第3期17-21,共5页
新型自走式红花丝采收机工作效率受到扶禾器与红花植株的相对位置影响。为此,针对红花丝采收机在采收时保持扶禾器与红花花丝相对位置,设计了一种仿形升降装置,使扶禾器工作达到效率最大化。对仿形装置进行受力及伸长量变化率分析,确定... 新型自走式红花丝采收机工作效率受到扶禾器与红花植株的相对位置影响。为此,针对红花丝采收机在采收时保持扶禾器与红花花丝相对位置,设计了一种仿形升降装置,使扶禾器工作达到效率最大化。对仿形装置进行受力及伸长量变化率分析,确定机构尺寸及伸长量变化率与位移的关系。综合考虑力学与位移,确定各液压杆的长度变化范围为600~1 050mm,辅助液压缸的长度变化范围400~500mm,纵向仿形量可达到500mm,横向仿形量可达到400mm。通过ADMAS仿真进行纵向仿形和横向仿形,纵向仿形量可达到580mm,横向仿形量可达到410mm,满足机械式红花丝采收机的运动仿形。该机构为研制机械式红花丝采收机提供了依据。 展开更多
关键词 升降装置 切割装置 仿形 运动仿真 红花采收机
在线阅读 下载PDF
上一页 1 2 91 下一页 到第
使用帮助 返回顶部 意见反馈