期刊文献+
共找到25,575篇文章
< 1 2 250 >
每页显示 20 50 100
Dopamine as a growth differentiation factor in the mammalian brain 预览
1
作者 Koji Ohira 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第3期390-393,共4页
The catecholamine,dopamine,plays an important role in the central nervous system of mammals,including executive functions,motor control,motivation,arousal,reinforcement,and reward.Dysfunctions of the dopaminergic syst... The catecholamine,dopamine,plays an important role in the central nervous system of mammals,including executive functions,motor control,motivation,arousal,reinforcement,and reward.Dysfunctions of the dopaminergic system lead to diseases of the brains,such as Parkinson’s disease,Tourette’s syndrome,and schizophrenia.In addition to its fundamental role as a neurotransmitter,there is evidence for a role as a growth differentiation factor during development.Recent studies suggest that dopamine regulates the development ofγ-aminobutyric acidergic interneurons of the cerebral cortex.Moreover,in adult brains,dopamine increases the production of new neurons in the hippocampus,suggesting the promoting effect of dopamine on proliferation and differentiation of neural stem cells and progenitor cells in the adult brains.In this mini-review,I center my attention on dopaminergic functions in the cortical interneurons during development and further discuss cell therapy against neurodegenerative diseases. 展开更多
关键词 γ-aminobutyric acidergic INTERNEURON adult NEUROGENESIS cerebral CORTEX DOPAMINE GABA MEDIAL ganglionic eminence migration STRIATUM
在线阅读 下载PDF
Migration routes and strategies of Grey Plovers(Pluvialis squatarola)on the East Atlantic Flyway as revealed by satellite tracking 预览
2
作者 Klaus-Michael Exo Franziska Hillig Franz Bairlein 《鸟类学研究:英文版》 CSCD 2019年第3期305-318,共14页
Background:While the general migration routes of most waders are known,details concerning connectivity between breeding grounds, stopover sites and wintering grounds are often lacking.Such information is critical from... Background:While the general migration routes of most waders are known,details concerning connectivity between breeding grounds, stopover sites and wintering grounds are often lacking.Such information is critical from the conservation perspective and necessary for understanding the annual cycle.Studies are especially needed to identify key stopover sites in remote regions. Using satellite transmitters, we traced spring and autumn migration routes and connectivity of Grey Plovers on the East Atlantic Flyway.Our findings also revealed the timing,flight speed, and duration of migrations. Methods:We used ARGOS satellite transmitters to track migration routes of 11 Grey Plovers that were captured at the German Wadden Sea where they had stopped during migration.Birds were monitored for up to 3 years,2011-2014.Results:Monitoring signals indicated breeding grounds in the Taimyr and Yamal regions;important staging sites on the coasts of the southern Pechora Sea and the Kara Sea;and wintering areas that ranged from NW-Ireland to Guinea Bissau.The average distance traveled from wintering grounds to breeding grounds was 5534 km. Migration duration varied between 42 and 152 days;during this period birds spent about 95% of the time at staging sites.In spring most plovers crossed inland Eastern Europe, whereas in autumn most followed the coastline.Almost all of the birds departed during favorable wind conditions within just 4 days (27-30 May) on northward migration from the Wadden Sea.In spring birds migrated significantly faster between the Wadden Sea and the Arctic than on return migration in autumn (12 vs.37 days),with shorter stopovers during the northward passage.Conclusions:Our study shows that satellite tags can shed considerable light on migration strategies by revealing the use of different regions during the annual cycle and by providing detailed quantitative data on population connectivity and migration timing. 展开更多
关键词 Annual cycle LONG-DISTANCE MIGRATION MIGRATION speed MIGRATION strategy MIGRATION timing Satellite transmitters SHOREBIRDS Tracking STOPOVER
在线阅读 免费下载
Stretching correction for amplitude-preserving vector wavefield reverse-time migration 预览
3
作者 Jia-jia Yang Bing-shou He +3 位作者 Hua-ning Xu Jun Pan Jun Liu Hong Liu 《中国地质(英文)》 2019年第2期179-188,共10页
The migration of multi-wave seismic data is aimed at obtaining the P- and S-wave imaging results of the amplitude preserving. But the P- and S-wave stretching effect produced by the reverse time migration of the elast... The migration of multi-wave seismic data is aimed at obtaining the P- and S-wave imaging results of the amplitude preserving. But the P- and S-wave stretching effect produced by the reverse time migration of the elastic wave equation will not only reduce the vertical resolution of the migration results and the amplitude preserving of the large reflection angle. In this paper, the reverse time migration technique of amplitude preserving vector wave-field separating is used. Based on the analysis of the stretch mechanism and the influencing factors of stretch magnitude, the paper gave the stretch correcting factors. Then, realize the stretch correction method at the time that after the reverse extrapolation and before the imaging by solving the problem which is how to calculate the P-wave and Ps-wave propagation directions of imaging points at different times. The stretch correction method can improve the vertical resolution and amplitude fidelity of the imaging results and provide high fidelity input data for seismic data interpretation and inversion. 展开更多
关键词 Reverse-time MIGRATION MULTI-WAVE and multi-component MIGRATION stretch CORRECTION Amplitude-preserving IMAGING Seismic MIGRATION IMAGING
在线阅读 免费下载
Diversity, Abundance, Richness, and Birds of Conservation Interest in Nyando Sugar Belt, Muhoroni Sub-County, Lake Victoria Basin, Western Kenya 预览
4
作者 Daniel Mokaya Mogaka Shadrack Muya +1 位作者 Francis Ndwigah Paul Ndang’ang’a 《动物科学期刊(英文)》 2019年第3期268-285,共18页
Thus far, no expedition has comprehensively surveyed the composition of bird species in the dilapidated habitats of Nyando sugar belt, Western Kenya. This has made it difficult unearthing equilibrium between agricultu... Thus far, no expedition has comprehensively surveyed the composition of bird species in the dilapidated habitats of Nyando sugar belt, Western Kenya. This has made it difficult unearthing equilibrium between agricultural growth and bird species conservation. In response, we conducted bird assessment by stratifying the expedition area into farmlands and shrub-land. We then sampled birds by the standard point count method and opportunistic counts within a 30 m radius parcel of land. We exhaustively observed 1450 birds of 122 species. The farmland recorded a density of 2.065 ± 1.11 birds per hectare whereas the shrub-land had a density of 1.644 ± 0.70 birds per hectare. Nyando sugar belt was a diverse community with a Shannon diversity index value (H’) of 3.225 regardless of the birds being constrained in certain habitats. The magnitude of the disparity in true diversity indicated that the farmland was 4 times more diverse than the shrub-land. The facts promoted by this research validate the incorporation of bird conservation in the farmland and formulation of avian conservation strategies. 展开更多
关键词 DIVERSITY ABUNDANCE Richness BIRDS Nyando CONSERVATION Migration Forest DEPENDENCY Kenya
在线阅读 免费下载
Assessing the Factors Influencing Migration Decision of Climate Refugees in Coastal Areas of Bangladesh 预览
5
作者 Tareq Mahamud Abir Xiaojun Xu 《美国气候变化期刊(英文)》 2019年第2期190-204,共15页
The major impacts of climate change play a substantial role in triggering human migration, especially in the coastal areas. The individual or combined effects of climate change are likely to trigger mass human movemen... The major impacts of climate change play a substantial role in triggering human migration, especially in the coastal areas. The individual or combined effects of climate change are likely to trigger mass human movement both within and across international borders. People rarely move for a single reason;the motivation to migrate is complex of many factors. The main goal of this article is to identify the factors related to the decision to migrate taken by refugees in the coastal area. To assess this objective we employ exploratory factor analysis and structural equation modeling (SEM) and find that different factors influence refugees’ migration decision differently. From the findings, it is seen that loss of shelter, extreme events, decreasing soil fertility and food shortage, variability in temperature patterns and exhaustion of natural resources are the most important environmental factors that affect the decision to migrate of climate refugees. Low income, increasing price, decreasing purchasing power are the most important economic factors that influence migration decision. No social factors have significant effect on migration decision while safety as a political factor has a moderate influence on refugees’ decision to migrate. Finally, this article provides some recommendations for recognition of and protection for migrants forced to move to safer places due to certain direct impacts of climate change, notwithstanding the existence of multi-causality. 展开更多
关键词 CLIMATE Change CLIMATE REFUGEE COASTAL Area MIGRATION
在线阅读 免费下载
Internal youth migration in Uganda:Analyzing associates and employment outcomes 预览
6
作者 Sandra Mirembe Abel Nzabona John A.Mushomi 《国际人口学期刊》 2019年第1期38-49,共12页
Youth internal migration is seen as a solution to youth unemployment,and this has resulted in over urbanization and its associated negative effects such as congestion,pollution,unemployment,underemployment,and increas... Youth internal migration is seen as a solution to youth unemployment,and this has resulted in over urbanization and its associated negative effects such as congestion,pollution,unemployment,underemployment,and increased crime rates.The study aimed at examining the employment status of youth migrants,assessing the relationship between demographic factors and youth internal migration,investigating the association between socio-economic factors and youth internal migration,and evaluating the association between reasons for migration and migrant employment status.The study used secondary data collected in the youth employment and migration in Eastern and Southern Africa project.In Uganda,the project was carried out in nine districts.The study focused on both men and women aged 18-35 years and a total number of 1524 respondents were interviewed.Results of the study revealed that age,residence,and region had a significant association with migration status(p≤0.05).Age,sex,number of children,region,and reasons for migration had a significant association with self-employment status of the migrant(p<0.05).Marital status,sex,and reasons for migration had an association with the possibility of a migrant youth being employed(p≤0.05).The study recommends that local governments should provide the required infrastructures,social services,and amenities to encourage youths to carry out economic activities so as to develop their places of origin. 展开更多
关键词 EMPLOYMENT status MIGRATION ASSOCIATES Social networks Uganda YOUTH INTERNAL MIGRATION
在线阅读 免费下载
Influences of coarse grid selection on Kirchhoff beam migration 预览
7
作者 LI Jiabin SUN Hui +2 位作者 ZHANG Zhihou HAN Fuxing LIU Minchen 《世界地质:英文版》 2019年第1期29-35,共7页
Kirchhoff beam migration is a beam migration method, which focuses on rapid imaging of geological structures. Although this imaging method ignores the amplitude information in the calculation process, it can calculate... Kirchhoff beam migration is a beam migration method, which focuses on rapid imaging of geological structures. Although this imaging method ignores the amplitude information in the calculation process, it can calculate multi-arrival traveltime. This migration method takes into account both imaging accuracy and computational efficiency. Kirchhoff beam migration employs coarse grid techniques in several key steps such as traveltime calculation, weight function calculation, and imaging calculation. The selection of the coarse mesh size has an important influence on the computational efficiency and imaging accuracy of the migration imaging method. This paper will analyze this influence and illustrate the analysis results by the Marmousi data sets. 展开更多
关键词 KIRCHHOFF BEAM MIGRATION prestack depth MIGRATION coarse GRID SELECTION BEAM propagator TRAVELTIME calculation
在线阅读 下载PDF
Right Testicle Ectopy Associated with Left Renal Agenesis 预览
8
作者 Mamadou Tidiani Coulibaly Ousmane Koné +3 位作者 Moumine Zié Diarra Amadou Berthé Lahassana Coulibaly Zanafon Ouattara 《外科学(英文)》 2019年第7期217-221,共5页
Testicular ectopia is a rare genital malformation belonging to the spectrum of testicular migration abnormalities. Renal agenesis can be unilateral or bilateral, isolated or associated with other malformations (1/4 of... Testicular ectopia is a rare genital malformation belonging to the spectrum of testicular migration abnormalities. Renal agenesis can be unilateral or bilateral, isolated or associated with other malformations (1/4 of renal agenesis is accompanied by genital malformations, and more often affects the left kidney. Few cases are reported in the literature. We report a case in a 28-year-old patient with ectopia of the right testicle in the suprapubic position associated with agenesis of the left kidney, and surgical management consisted of an orchiectomy, with good surgical results. 展开更多
关键词 TESTIS AGENESIS KIDNEY Migration
在线阅读 免费下载
建筑迁徙的内生逻辑研究以客家建筑为例 预览
9
作者 孙彤宇 郑鸣 《时代建筑》 2019年第4期148-153,共6页
在当前新乡村建设的背景下,农村人口的迁移聚居改变了传统的乡村空间形态和生活形态,新乡村建设在改善物质环境和完善生活设施配套的同时,乡村的地域文化传承成为一个不容忽视且具有挑战性的课题。文章从人地关系理论出发,以客家建筑为... 在当前新乡村建设的背景下,农村人口的迁移聚居改变了传统的乡村空间形态和生活形态,新乡村建设在改善物质环境和完善生活设施配套的同时,乡村的地域文化传承成为一个不容忽视且具有挑战性的课题。文章从人地关系理论出发,以客家建筑为例,结合类型学和移民适应性理论分析客家建筑迁徙过程中建筑文化演进的涵化现象,总结建筑迁徙中潜在的内生逻辑,并概括为三个方面,即"环境关联性""系统关联性"和"文化关联性",为当前新乡村建设中更好地实现建筑文化传承提供了参考和借鉴。 展开更多
关键词 人口迁移 建筑迁徙 内生逻辑 文化传承 涵化现象
在线阅读 下载PDF
Damage to <i>Salamandra infraimmaculata</i>Populations by Human Activity in Creating Water Pits Is a Death Trap in Semi-Arid Habitats 预览
10
作者 Gad Degani Udi Grosman +1 位作者 Tali Goldberg Nadav Hanegbi 《动物科学期刊(英文)》 2019年第1期23-34,共12页
The different breeding sites of Salamandra infraimmaculata on the southern border of its distribution were examined and mapped in order to estimate the damage caused by water holes that could represent death traps for... The different breeding sites of Salamandra infraimmaculata on the southern border of its distribution were examined and mapped in order to estimate the damage caused by water holes that could represent death traps for salamanders in xeric habitats. Among the various types of breeding sites (springs, streams, water holes, winter pools and reservoirs), the larvae of salamanders were detected in high numbers in springs and streams (503) and water holes (48), and in relatively low numbers in winter pools. Two water holes were examined in detail to estimate the damage caused to S. infraimmaculata where breeding places are limited. During the winter, both males and females enter a water hole for breeding. The percentage of males in and around the water hole was 42% and that of females 29%. After the salamanders’ oviposition in the water, they try to return to terrestrial habitats, but are unable to do so and lose weight and die. The body mass index (BMI) of salamanders decreases from winter (December) after they move to the water hole to spring (April), when they are found in the water hole. The estimation of potential damage is about 300 mature salamanders annually. 展开更多
关键词 AMPHIBIA Body Mass Israel Migration Reproduction Cycle SALAMANDRA
在线阅读 免费下载
Enhancement of Effective Accumulation of Atoms during Fabrication of Al Microsphere 预览
11
作者 Faizul Mohammad Kamal Md. Nazrul Islam Khan 《显微镜研究(英文)》 2019年第4期39-46,共8页
Microspheres of Al have been successfully fabricated utilizing electromigration using sudden change in geometrical shape of a specimen. The experimental sample was a passivated Al line with a hole at the transitional ... Microspheres of Al have been successfully fabricated utilizing electromigration using sudden change in geometrical shape of a specimen. The experimental sample was a passivated Al line with a hole at the transitional area of the sample. The hole was used to control the accumulation and discharge process. The formation of the microsphere is enhanced by controlling temperature and current density. The atomic flux was increased with the increasing current density that was happened along the electron flow direction in the small region at the geometrical shape of the sample. 展开更多
关键词 ELECTROMIGRATION ATOMS MIGRATION MICROSPHERE ACCUMULATION
在线阅读 免费下载
草鱼洄游的适宜流速条件与适应阈值
12
作者 杨庆 胡鹏 +2 位作者 杨泽凡 储立民 杨静 《水生态学杂志》 CSCD 北大核心 2019年第4期93-100,共8页
洄游通道的连通性及其水文条件,是制约鱼类正常洄游和产卵繁殖的关键因素,现有的生态流量相关研究更多侧重于产卵场栖息地模拟,忽略了鱼类洄游水流条件的重要性。为了探究流速条件对鱼类洄游上溯的影响,选取体长(55±5)cm的草鱼(Cte... 洄游通道的连通性及其水文条件,是制约鱼类正常洄游和产卵繁殖的关键因素,现有的生态流量相关研究更多侧重于产卵场栖息地模拟,忽略了鱼类洄游水流条件的重要性。为了探究流速条件对鱼类洄游上溯的影响,选取体长(55±5)cm的草鱼(Ctenopharyngodon idellus)为实验对象,通过搭建鱼类洄游仿真河道,营造不同的流速工况,观察不同情景方案下实验鱼群上溯洄游情况,并利用模糊逻辑法对鱼类上溯洄游率、平均上溯时间及上溯持续性等实验参数进行综合分析,探索草鱼洄游的适宜流速条件与适应阈值。结果显示,在流速0.20m/s以下时,草鱼基本无上溯行为;流速0.25~0.80m/s,70%样本在15min内完成上溯,但0.25~0.30m/s时,鱼群上溯缺乏明显的持续性;0.90~1.00m/s时,80%以上样本在5min快速完成上溯;流速超过1.1m/s时,上溯成功率明显降低。研究表明,实验草鱼洄游的适宜流速范围是0.40~1.00m/s,而刺激草鱼洄游的最小流速阈值是0.20m/s。相关结果可为河流生态水力学模拟和河流生态修复以及水利工程生态调度提供技术支撑。 展开更多
关键词 草鱼 洄游 流速 阈值
农业转移人口的超大城市偏好与家庭联合迁移决策 预览
13
作者 赵海涛 朱帆 《人口与经济》 CSSCI 北大核心 2019年第3期77-90,共14页
夫妻双方同时外出务工以及在超大城市集聚是农业转移人口城乡转移的重要趋势。基于2014年全国流动人口动态监测调查数据,利用多元选择模型,考察了已婚农业转移人口的超大城市偏好与七类联合迁移决策,得到的主要结论有:夫妻同时外出务工... 夫妻双方同时外出务工以及在超大城市集聚是农业转移人口城乡转移的重要趋势。基于2014年全国流动人口动态监测调查数据,利用多元选择模型,考察了已婚农业转移人口的超大城市偏好与七类联合迁移决策,得到的主要结论有:夫妻同时外出务工是家庭迁移的主要模式,相对于妻子,丈夫外出务工的概率更高,且更加偏好超大城市流动;迁移至超大城市和其他城市用于家庭照料的时间投入和经济回报是有差异的,随着家庭孩子数量增加,夫妻迁移至两类城市的概率表现出不同的变化趋势,其中丈夫迁移至超大城市、丈夫迁移至其他城市、妻子迁移至其他城市的概率均呈现先下降后上升的“U”型特征;和老一代农业转移人口相比,在家庭孩子数量相同的情况下,新生代农业转移人口家庭夫妻双方外出务工的概率均更高,且丈夫迁移至超大城市的比例更大。 展开更多
关键词 农业转移人口 超大城市 联合迁移决策 家庭
在线阅读 下载PDF
miR-128-3p过表达靶向MAPK1抑制膀胱癌5637细胞株的侵袭,迁移和上皮间质转化
14
作者 赵阳 万银绪 +2 位作者 车吉忠 徐延凯 李庆元 《中国临床解剖学杂志》 CSCD 北大核心 2019年第5期534-541,共8页
目的 研究miR-128-3p过表达对膀胱癌5637细胞株的侵袭,迁移和上皮间质转化影响。方法 基因预测软件TargetScan筛选出miR-128-3p的靶基因,荧光素酶报告实验验证;RT-PCR检测miR-128-3p和MAPK1的表达,Transwell检测细胞侵袭情况,划痕实验... 目的 研究miR-128-3p过表达对膀胱癌5637细胞株的侵袭,迁移和上皮间质转化影响。方法 基因预测软件TargetScan筛选出miR-128-3p的靶基因,荧光素酶报告实验验证;RT-PCR检测miR-128-3p和MAPK1的表达,Transwell检测细胞侵袭情况,划痕实验检测细胞迁移能力,Western blot检测Ecadherin、N-cadherin、ERK1/2、c-Myc和c-fos的表达,免疫荧光检测Vimentin的表达;裸鼠皮下注射建立移植瘤模型,30 d后检测瘤重量,绘制存活曲线,检测移植瘤中Vimentin、miR-128-3p、MAPK1、ERK1/2、cMyc和c-fos的量。结果 miR-128-3p靶向抑制MAPK1表达;miR-128-3p过表达后,侵袭细胞数目、伤口愈合率降低,E-cadherin表达上调,N-cadherin表达下调,Vimentin阳性率减少,p-ERK1/2、c-Myc和c-fos表达下调。经miR-128-3p干预,裸鼠体内移植瘤重量减轻,存活率增加,miR-128-3p表达上调,MAPK1的表达下调,Vimentin阳性率减少,p-ERK1/2、c-Myc和c-fos表达下调。结论 过表达miR-128-3p通过靶向抑制MAPK1表达来抑制膀胱癌细胞5637的侵袭能力、迁移能力、上皮-间充质转化和ERK1/2、cMyc和c-fos通路。 展开更多
关键词 miR-128-3p MAPK1 膀胱癌细胞5637 侵袭 迁移 上皮间质转化
碧萝芷对乳腺癌MCF-7细胞增殖、迁移和转移的影响 预览
15
作者 杨春姝 秦光远 郑新宇 《中华乳腺病杂志(电子版)》 CAS CSCD 2019年第3期165-172,共8页
目的探讨抗氧化剂碧萝芷对乳腺癌MCF-7细胞的抑制作用,并对观察碧萝芷对MCF-7细胞的转移和迁移功能的影响。方法用10、20、40μg/ml的碧萝芷处理乳腺癌MCF-7细胞作为实验组,空白对照组只加入DMEM培养基(无血清), MTT法在处理细胞后24、4... 目的探讨抗氧化剂碧萝芷对乳腺癌MCF-7细胞的抑制作用,并对观察碧萝芷对MCF-7细胞的转移和迁移功能的影响。方法用10、20、40μg/ml的碧萝芷处理乳腺癌MCF-7细胞作为实验组,空白对照组只加入DMEM培养基(无血清), MTT法在处理细胞后24、48、72 h于波长490 nm处测定各组吸光度值;用流式细胞仪检测细胞凋亡率;用β-半乳糖苷酶染色法检测MCF-7细胞衰老率;用Transwell小室法分别检测各浓度碧萝芷对乳腺癌MCF-7细胞迁移和侵袭能力的影响;用Western blot法分别检测乳腺癌MCF-7细胞衰老相关蛋白P53、P21、P16、P27、E2F1以及基质金属蛋白酶(matrix metalloproteinase, MMP)-2、MMP-9的表达。细胞迁移、侵袭数目及各种蛋白的表达水平比较采用单因素方差分析,吸光度值比较采用重复测量的方差分析,两两比较采用LSD法。结果 MTT结果显示,在处理乳腺癌MCF-7细胞24、48、72 h后,各组吸光度值比较,差异有统计学意义(F=149.439,P<0.001),在不同时间点之间比较,差异有统计学意义(F=27.922,P<0.001);分组与时间点之间存在交互作用(F=18.466,P<0.001)。流式细胞仪检测结果显示:空白对照组及10、20、40μg/ml碧萝芷组的细胞凋亡率分别为(2.36±0.27)%、(6.44±1.43)%、(7.52±2.09)%和(11.68±1.65)%,差异有统计学意义(F=19.143,P<0.001)。β-半乳糖苷酶染色法结果显示:空白对照组和10、20、40μg/ml碧萝芷组的细胞衰老率分别为(5.35±1.32)%、(20.08±2.14)%、(40.55±4.61)%和(59.26±4.10)%,差异有统计学意义(F=150.150,P<0.001)。Transwell小室结果显示:空白对照组及10、20、40μg/ml碧萝芷组的迁移细胞数目分别为(41±5)、(27±2)、(19±1)、(11±2)个,差异有统计学意义(F=59.330,P<0.001);侵袭转移的细胞数目分别为(24±4)、(17±1)、(12±2)、(7±2)个,差异也有统计学意义(F=26.230,P<0.001)。Western blot结果显示:碧萝芷可上调P53、P21、P16、P27蛋白表达(F=263.905、424.937、217.515、391 展开更多
关键词 乳腺肿瘤 细胞衰老 迁移 转移 碧萝芷
在线阅读 下载PDF
东濮凹陷油气藏成藏特征差异以及深层油气成藏过程 预览
16
作者 李兴宇 郭彬程 《当代化工研究》 2019年第5期45-46,共2页
东濮凹陷是渤海湾盆地中既富油又富气的凹陷,对于古近系深层油气的开发具有良好的前景。虽然我国对东濮凹陷油气勘探已达到了中等勘探程度,但是关于该区深层油气的成藏机理还不是很清晰,尤其是深层油气的相态演化、油气充注序列、动态... 东濮凹陷是渤海湾盆地中既富油又富气的凹陷,对于古近系深层油气的开发具有良好的前景。虽然我国对东濮凹陷油气勘探已达到了中等勘探程度,但是关于该区深层油气的成藏机理还不是很清晰,尤其是深层油气的相态演化、油气充注序列、动态成藏机制及其主控因素研究还处于一个起步期。 展开更多
关键词 东濮凹陷 烃源岩 相态演化 分布序列 运移 成藏过程
在线阅读 下载PDF
盐霉素对大鼠微血管内皮细胞血管生成的抑制 预览
17
作者 王薇 王俊壹 +4 位作者 薛兴功 宋玮 段秋莉 肖荣 张普 《中华临床医师杂志(电子版)》 CAS 2019年第4期290-293,共4页
目的探讨盐霉素是否可通过抑制大鼠微血管内皮细胞的增殖、迁移、侵袭抑制血管生成。方法取6~8周雄性Wistar大鼠心脏,应用植块法原代培养大鼠微血管内皮细胞,取第三代细胞进行实验。给予不同浓度的盐霉素刺激大鼠微血管内皮细胞,采用MT... 目的探讨盐霉素是否可通过抑制大鼠微血管内皮细胞的增殖、迁移、侵袭抑制血管生成。方法取6~8周雄性Wistar大鼠心脏,应用植块法原代培养大鼠微血管内皮细胞,取第三代细胞进行实验。给予不同浓度的盐霉素刺激大鼠微血管内皮细胞,采用MTT方法检测盐霉素对大鼠微血管内皮细胞增值能力的影响。采用细胞损伤划痕实验检测盐霉素对大鼠微血管内皮细胞迁移能力的影响,应用Transwell实验方法检测盐霉素对大鼠微血管内皮细胞侵袭能力的影响。采用体外毛细血管管腔样结构形成方法观察盐霉素对毛细血管管腔样结构官腔形成能力的影响,验证盐霉素对大鼠微血管内皮细胞血管生成能力的影响。采用t检验比较对照组与各实验组之间吸光度值、划痕距离差、Transwell细胞数以及体外毛细血管管腔样结构形成条数的差异。结果MTT检测细胞增殖能力显示,对照组吸光度值(0.968±0.038)相比SAL在1μM(0.849±0.031)时已高,且差异具有统计学意义(t=4.11,P=0.0367),即可明显抑制细胞增殖,且呈浓度依赖性。细胞划痕损伤修复能力检测结果显示,与对照组划痕距离[(249.78±6.72)μm]相比,VEGF组划痕距离[(289.67±8.59)μm]更大,促进了划痕修复,差异具有统计学意义(t=4.76,P=0.0165),SAL组划痕距离[(98.59±4.78)μm]减小,抑制了划痕修复,差异具有统计学意义(t=30.6,P=0.0007)。Transwell实验结果显示,与对照组细胞数(128.67±4.89)个相比,VEGF组细胞数[(158.23±5.26)个]增加,促进了细胞侵袭,差异具有统计学意义(t=5.65,P=0.0089),SAL组细胞数[(98.59±4.78)个]减少,抑制了细胞侵袭,差异具有统计学意义(t=25.65,P<0.001)。体外毛细血管管腔样结构形成实验结果显示,与对照组[(31.29±1.68)条]比较,VEGF组形成[(45.76±2.56)条]更多,促进了血管新生,差异具有统计学意义(t=3.90,P=0.0176),SAL组形成[(14.38±1.23)条]减少,抑制了血管新生,差异具 展开更多
关键词 盐霉素 微血管内皮细胞 迁移 侵袭 血管生成
在线阅读 下载PDF
miR-450b-5p在肝细胞癌中的表达及功能 预览
18
作者 张雷 王宇锋 +5 位作者 王亮 殷国志 韩少山 李瑞祥 鲜瑶 姚德茂 《西安交通大学学报:医学版》 CAS CSCD 北大核心 2019年第5期747-754,共8页
目的探究miR-450b-5p在肝细胞癌(hepatocellular carcinoma,HCC)中的表达情况、临床意义及生物学功能,并初步探究其潜在的作用机制。方法Real-time PCR检测miR-450b-5p在HCC组织和细胞系的表达情况;分析miR-450b-5p的表达水平与HCC临床... 目的探究miR-450b-5p在肝细胞癌(hepatocellular carcinoma,HCC)中的表达情况、临床意义及生物学功能,并初步探究其潜在的作用机制。方法Real-time PCR检测miR-450b-5p在HCC组织和细胞系的表达情况;分析miR-450b-5p的表达水平与HCC临床病理特征及患者预后的相关性,并用Cox多因素回归分析法分析患者的独立预后因素;采用Transwell迁移和侵袭实验检测miR-450b-5p对HCC细胞迁移与侵袭能力的影响;MTT实验观察miR-450b-5p对HCC细胞增殖能力的影响;应用生物信息学工具预测miR-450b-5p的下游靶点,并应用荧光素酶报告实验及Western blot分析miR-450b-5p对靶点的调节作用。结果 miR-450b-5p在HCC组织和细胞系中的表达均明显降低(均P<0.001);miR-450b-5p的表达水平与肿瘤大小(P=0.026)、静脉侵犯(P=0.013)、TNM分期(P=0.020)及HCC患者的预后(P=0.014 2)相关,且Cox多因素回归分析结果显示miR-450b-5p为HCC患者的独立预后因素之一;上调MHCC-97H细胞的miR-450b-5p表达后,细胞迁移、侵袭和增殖能力显著被抑制;而下调Hep3B的miR-450b-5p表达时,细胞的迁移、侵袭和增殖能力明显增强;生物信息学分析发现,性别决定区Y框蛋白2(sex determining region Y-box2,SOX2)可能是miR-450b-5p的作用靶点;荧光素酶报告实验显示,miR-450b-5p能够负向调节SOX2-3′UTR的荧光素酶活性;miR-450b-5p mimics能降低MHCC-97H细胞中SOX2的表达水平,miR-450b-5p inhibitors能上调Hep3B细胞中SOX2的表达水平。结论 miR-450b-5p通过靶向作用于SOX2抑制HCC细胞的迁移、侵袭及增殖,进而抑制HCC的发生发展。 展开更多
关键词 肝细胞癌 miR-450b-5p SOX2 迁移 侵袭 增殖
在线阅读 下载PDF
辽宁兴城地区绥中花岗岩-棕壤土矿质元素迁移特征 预览
19
作者 陶景梅 王建国 +2 位作者 刘欣玥 韩亚杰 刘志川 《世界地质》 CAS 2019年第3期636-642,共7页
辽宁兴城地区以绥中花岗岩为成土母质的酸性棕壤土是一种具有特色的农作土壤。对绥中花岗岩与土壤中矿质元素的迁移规律的研究表明,基岩、成土母质、底土层、心土层和耕作层中的矿物组合、矿物形态及地球化学具有相似性。酸性棕壤土的... 辽宁兴城地区以绥中花岗岩为成土母质的酸性棕壤土是一种具有特色的农作土壤。对绥中花岗岩与土壤中矿质元素的迁移规律的研究表明,基岩、成土母质、底土层、心土层和耕作层中的矿物组合、矿物形态及地球化学具有相似性。酸性棕壤土的物质来源于基岩的残积或近地运积。土壤各发生层中的Si、Fe、K、Mn等常量元素具有显著高值,稀土元素富集。酸性棕壤土矿物分解处于钙淀积-酸性硅铝阶段。化学风化作用过程完成了初始的去Ca、Na过程,进入到去K的阶段,矿质元素迁移表现为母岩高物理风化程度和棕壤土对有效元素的高继承性的特征。 展开更多
关键词 兴城地区 矿质元素 迁移 绥中花岗岩 棕壤土
在线阅读 下载PDF
凋亡蛋白抑制因子Livin在子宫内膜癌中的表达及其对肿瘤细胞侵袭和迁移能力的影响
20
作者 王晓华 张玉娟 《上海医学》 CAS 北大核心 2019年第4期222-226,共5页
目的研究凋亡蛋白抑制因子Livin在子宫内膜癌中的表达及其对肿瘤细胞侵袭和迁移能力的影响。方法选取承德医学院附属医院妇科2015年3月—2016年10月手术切除的子宫内膜标本共118例,其中子宫内膜癌组织62例,非典型增生内膜组织26例,正常... 目的研究凋亡蛋白抑制因子Livin在子宫内膜癌中的表达及其对肿瘤细胞侵袭和迁移能力的影响。方法选取承德医学院附属医院妇科2015年3月—2016年10月手术切除的子宫内膜标本共118例,其中子宫内膜癌组织62例,非典型增生内膜组织26例,正常子宫内膜组织30例。采用荧光定量PCR法检测并比较Livin mRNA在子宫内膜癌、非典型增生和正常内膜组织中,以及在不同临床病理特征子宫内膜癌组织中的表达,分析其差异性表达与子宫内膜癌临床病理分期的关系。采用脂质体法用Livin的小分子干扰RNA(Livin-siRNA)和阴性对照序列(Livin-NC)转染Ishikawa和HEC-1-A细胞,分为ISK-I组和HEC-I组(均转染Livin-siRNA)、ISK-NC组和HEC-NC组(均转染Livin-NC)、ISK-B组和HEC-B组(均仅以10%FBS培养细胞)。转染后48 h,采用Western印迹法检测并比较Livin蛋白在各组细胞中的表达。进行Transwell小室侵袭和迁移实验,观察干扰Livin对细胞侵袭和迁移能力的影响。结果 Livin mRNA在子宫内膜癌组织中的相对表达量(8.624±0.264)显著高于非典型增生内膜组织(3.497±0.186)和正常内膜组织(1.000±0.098,P值均<0.05)。比较Livin mRNA在不同年龄(<60岁与≥60岁)、不同肌层浸润深度(<1/2与≥1/2)、不同病理分级(G1级与G2+G3级)、不同国际妇产科联盟(FIGO)分期(Ⅰ或Ⅱ期与Ⅲ或Ⅳ期)和有无淋巴结转移的患者中的表达,结果显示,Livin mRNA仅在不同肌层浸润深度(相对表达量分别为6.392±0.149和9.227±0.216,t=7.325,P=0.016)和不同病理分级(相对表达量分别为7.068±0.103和9.392±0.125,t=5.578,P=0.027)的患者中表达的差异均有统计学意义。转染后48 h,ISK-I组(0.395±0.012)和HEC-I组(0.514±0.022)的Livin蛋白相对表达量分别显著低于ISK-NC组(1.108±0.048)、HEC-NC组(1.426±0.062)、ISK-B组(1.164±0.054)和HEC-B组(1.448±0.071,P值均<0.05)。侵袭实验结果显示,ISK-I组[(20.2±3.6)个]和HEC-I组[(28.8±3.2)个]的穿膜细 展开更多
关键词 子宫内膜肿瘤 RNA 小分子干扰 肿瘤浸润 凋亡蛋白抑制因子 LIVIN 迁移
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈