期刊文献+
共找到227篇文章
< 1 2 12 >
每页显示 20 50 100
论苗族非物质文化遗产保护传承的理想模式 被引量:1
1
作者 罗义群 《管理观察》 2011年第36期189-190,共2页
苗族非物质文化遗产保护传承模式,共有五种,已经形成的有四种,那就是:“自发保护,精英助推”;“文化搭台,经济唱戏”;“政府主导,人大立法”;“大系统带小系统,小系统促大系统”等。随着社会经济的发展,苗族非物质文化遗产... 苗族非物质文化遗产保护传承模式,共有五种,已经形成的有四种,那就是:“自发保护,精英助推”;“文化搭台,经济唱戏”;“政府主导,人大立法”;“大系统带小系统,小系统促大系统”等。随着社会经济的发展,苗族非物质文化遗产保护传成的理想模式将会形成,那就是“政府主导给力,法制保驾护航,经济文化协调,文化持有者自觉参与,全社会积极行动”。 展开更多
关键词 苗族 非物质文化遗产 传成 理想模式
下载PDF
论《说文解字》的文字学成就──兼评对《说文解字》文字学成就的否定 被引量:1
2
作者 陈蒲清 《船山学刊》 2000年第4期61-65,共5页
关键词 《说文解字》 文字学 中国 发展轨迹 文化传成
全文增补中
Asymmetrical Fabry-Perot cavity slot micro-ring resonator and its sensing characteristics
3
作者 CAO Qianqian LIU Chunjuan +1 位作者 WU Xiaosuo SUN Xiaoli 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期292-301,共10页
To achieve high quality factor and high-sensitivity refractive index sensor,a slot micro-ring resonator(MRR)based on asymmetric Fabry-Perot(FP)cavity was proposed.The structure consisted of a pair of elliptical holes ... To achieve high quality factor and high-sensitivity refractive index sensor,a slot micro-ring resonator(MRR)based on asymmetric Fabry-Perot(FP)cavity was proposed.The structure consisted of a pair of elliptical holes to form an FP cavity and a microring resonator.The two different optical modes generated by the micro-ring resonator were destructively interfered to form a Fano line shape,which improved the system sensitivity while obtaining a higher quality factor and extinction ratio.The transmission principle of the structure was analyzed by the transfer matrix method.The transmission spectrum and mode field distribution of the proposed structure were simulated by the finite difference time domain(FDTD)method,and the key structural parameters affecting the Fano line shape in the device were optimized.The simulation results show that the quality factor of the device reached 22037.1,and the extinction ratio was 23.9 dB.By analyzing the refractive index sensing characteristics,the sensitivity of the structure was 354 nm·RIU−1,and the detection limit of the sensitivity was 2×10−4 RIU.Thus,the proposed compact asymmetric FP cavity slot micro-ring resonator has obvious advantages in sensing applications owing to its excellent performance. 展开更多
关键词 micro-ring resonator(MRR) Fabry-Perot(FP)cavity Fano resonance refractive index sensing integrated optics silicon waveguide
下载PDF
Ovule Development, Formation of Pollination Drop and Pollination Process in Taxus chinensis (Taxaceae) 被引量:11
4
作者 邢树平 陈祖铿 +2 位作者 胡玉熹 周馥 林金星 《Acta Botanica Sinica》 CSCD 2000年第2期126-132,共7页
Pollen morphology and hydration, ovule development, formation of pollination drop and the pollination process of Taxus chinensis (Pilg.) Rehd were investigated in detail. The results showed that mature pollen was ... Pollen morphology and hydration, ovule development, formation of pollination drop and the pollination process of Taxus chinensis (Pilg.) Rehd were investigated in detail. The results showed that mature pollen was one_celled, irregular in shape, nonsaccate, and the surface was covered with orbicules. When pollen became hydrated, the intine swelled and the exine bursted. The exine usually remained on the surface of water or on the pollination drop all the time, while the rest portion of the pollen sank into the drop of water or the pollination drop. In the late August, the down_curved female buds could be observed in the field trees. The downturning of the female buds was an characteristic feature discriminating from the vegetative buds. At this stage ovular primordium was present in the female bud with a dome_shaped nucellar primordium encircled by a rudimentary integument. The integument grew fast and overgrew the nucellus. In the March of the following year, the ovule formed a micropylar canal about 1?000 μm in length, 200-300 μm in width. Except the micropyle, the other part of the ovule was enclosed by 20-25 scales. During the early stage of the ovule development, the nucellar surface clearly showed cell configuration; but a membrane_like structure covering the nucellar apex appeared in the late stage of the ovule development, and subsequently broke down with nucellar cell disintegration before pollen shedding. The disintegrated cell products might partake in the formation of the pollination drop. Before and during pollination, the nucellar cells contained abundant mitochondria, endospermic reticulum and dictysomes with vesicles; the plasma membrane was undulated and there was no accumulation of electron_dense substances in the pericytoplasm. Pollination drops usually occurred at night, and disappeared by noon in the field tree. 15 days before pollination, the in vitro ovules from the field trees already had the capability of producing pollination drops, which could last for 4-5 days indoors. However, after these drops received pollen, they did not withdraw noticeably compared with the unpollinated ones. The retraction of the pollination drop was presumed not to be a nonmetabolic outcome but rather a result of evaporation. 展开更多
关键词 Taxus chinensis POLLEN ovule development nucellar ultrastructure pollination drop
下载PDF
Elsholtzia:review of traditional uses,chemistry and pharmacology 被引量:2
5
作者 刘艾林 Simon M.Y. Lee +2 位作者 李铭源 王一涛 杜冠华 《Journal of Chinese Pharmaceutical Sciences》 CAS 2007年第2期73-78,共6页
The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available show... The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available shows that these species are used mostly for the treatment of respiratory and gastrointestinal disorders. Additionally, some of these Elsholtzia species show antibacterial, anti-inflammatory, relieving fever, analgesic activities and myocardial ischemia protection. Generally, the essential oils or flavonoids from these plant extracts are assumed to be the active principles. 展开更多
关键词 Elsholtzia species Chemical constituent Traditional uses LABIATAE
下载PDF
Adaptive genetic algorithm with the criterion of premature convergence 被引量:9
6
作者 袁晓辉 曹玲 夏良正 《Journal of Southeast University(English Edition)》 EI CAS 2003年第1期40-43,共4页
To counter the defect of traditional genetic algorithms, an improved adaptivegenetic algorithm with the criterion of premature convergence is provided. The occurrence ofpremature convergence is forecasted using colony... To counter the defect of traditional genetic algorithms, an improved adaptivegenetic algorithm with the criterion of premature convergence is provided. The occurrence ofpremature convergence is forecasted using colony entropy and colony variance. When prematureconvergence occurs, new individuals are generated in proper scale randomly based on superiorindividuals in the colony. We use these new individuals to replace some individuals in the oldcolony. The updated individuals account for 30 percent - 40 percent of all individuals and the sizeof scale is related to the distribution of the extreme value of the target function. Simulationtests show that there is much improvement in the speed of convergence and the probability of globalconvergence. 展开更多
关键词 genetic algorithm premature convergence ADAPTATION
下载PDF
Evaluation of volcanic reservoirs with the "QAPM mineral model" using a genetic algorithm 被引量:8
7
作者 潘保芝 薛林福 +2 位作者 黄布宙 闫桂京 张丽华 《Applied Geophysics》 SCIE CSCD 2008年第1期1-8,共8页
Gas-bearing volcanic reservoirs have been found in the deep Songliao Basin, China. Choosing proper interpretation parameters for log evaluation is difficult due to complicated mineral compositions and variable mineral... Gas-bearing volcanic reservoirs have been found in the deep Songliao Basin, China. Choosing proper interpretation parameters for log evaluation is difficult due to complicated mineral compositions and variable mineral contents. Based on the QAPF classification scheme given by IUGS, we propose a method to determine the mineral contents of volcanic rocks using log data and a genetic algorithm. According to the QAPF scheme, minerals in volcanic rocks are divided into five groups: Q(quartz), A (Alkaline feldspar), P (plagioclase), M (mafic) and F (feldspathoid). We propose a model called QAPM including porosity for the volumetric analysis of reservoirs. The log response equations for density, apparent neutron porosity, transit time, gamma ray and volume photoelectrical cross section index were first established with the mineral parameters obtained from the Schlumberger handbook of log mineral parameters. Then the volumes of the four minerals in the matrix were calculated using the genetic algorithm (GA). The calculated porosity, based on the interpretation parameters, can be compared with core porosity, and the rock names given in the paper based on QAPF classification according to the four mineral contents are compatible with those from the chemical analysis of the core samples. 展开更多
关键词 QAPM mineral model well logs genetic algorithm volcanic reservoirs
下载PDF
A Monolithic Integrated CMOS Thermal Vacuum Sensor 被引量:2
8
作者 张凤田 唐祯安 +1 位作者 汪家奇 余隽 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第6期1103-1107,共5页
The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate (MHP) and operating... The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate (MHP) and operating under constant bias voltage conditions was designed. A new monolithic integrating mode was proposed,in which the dielectric and passiva- tion layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor. Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0. 6μm mixed signal CMOS process followed by sacrificial layer etching technology. The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2- 10^5 Pa and the output voltage is adjustable. 展开更多
关键词 thermal vacuum sensor monolithic integration CMOS micro hotplate
下载PDF
Potato Y Potyvirus Helper Component Proteinase Enhances Long-distance Movement of Potato X Potexvirus 被引量:1
9
作者 李为民 鲁瑞芳 +2 位作者 郭明 陈毓荃 彭学贤 《Acta Botanica Sinica》 CSCD 2001年第9期935-940,共6页
To mutagenize two conserved CCCT and PTK motifs in the central domain of Chinese strain of potato Y potyvirus (PVY-C) helper component proteinase (HC-Pro), four mutants of HC-Pro gene were obtained by PCR and site-dir... To mutagenize two conserved CCCT and PTK motifs in the central domain of Chinese strain of potato Y potyvirus (PVY-C) helper component proteinase (HC-Pro), four mutants of HC-Pro gene were obtained by PCR and site-directed mutagenesis, and then were inserted into the constitutive expression vector pBin438. Leaves from tobacco (Nicotiana tabacum L. cv. K326) were transformed with these four plant expression plasmids by Agrobacterium-mediated transformation, respectively. Southern and Western blotting analyses showed that these four mutants were integrated into tobacco genomic DNA and could express the corresponding proteins in most of die transgenic plants. The challenge of transgenic plants with potato X potexvirus (PVX) revealed that the expression products of PVY-C HC-Pro mutants in transgenic plants greatly abolished functions of HC-Pro in enhancing the accumulation and pathogenicity of PVX, indicating that CCCT and PTK motifs of HC-Pro were required for PVX/PVY synergism. Meanwhile, the results demonstrated that PVY-C HC-Pro had a function in accelerating the long-distance movement of PVX in these transgenic plants for the first time. 展开更多
关键词 potato Y potyvirus potato X potexvirus helper component proteinase gene mutation synergism
下载PDF
STUDY OF FLOW AND TEMPERATURE IN RESIN TRANSFER MOLDING PROCESS BY NUMERICAL MODEL
10
作者 陈仁良 李明成 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期165-171,共7页
A mathematical model of resin flow and temperature variation in the filling stage of the resin transfer molding (RTM) is developed based on the control volume/finite element method (CV/FEM). The effects of the heat tr... A mathematical model of resin flow and temperature variation in the filling stage of the resin transfer molding (RTM) is developed based on the control volume/finite element method (CV/FEM). The effects of the heat transfer and chemical reaction of the resin on the flow and temperature are considered. The numerical algorithm of the resin flow and temperature variation in the process of RTM are studied. Its accuracy and convergence are analyzed. The comparison of temperature variations between experimental results and model predictions is carried out for two RTM cases. Result shows that the model is efficient for evaluating the flow and temperature variation in the filling stage of RTM and there is a good coincidence between theory and experiment. 展开更多
关键词 resin transfer molding mathematical modeling numerical algorithm heat transfer
下载PDF
Screening for genetic loci affecting the active zone formation in C. elegans
11
作者 王大勇 汪洋 《Neuroscience Bulletin》 SCIE CAS CSCD 2006年第5期301-304,共4页
Objective To screen and identify genetic loci affecting the active zone formation in C. elegans. Methods A SYD-2::GFP reporter was constructed and used as an active zone marker for forward genetic screen to identify... Objective To screen and identify genetic loci affecting the active zone formation in C. elegans. Methods A SYD-2::GFP reporter was constructed and used as an active zone marker for forward genetic screen to identify genetic loci affecting the active zone formation. Results Eight isolated mutant alleles were characterized from 15,000 haploid genomes. The SYD-2::GFP phenotypes of these mutants are mainly reflected as the changes of number, morphology, distribution of puncta and the gaps appearance. Some mutants also exhibit visible behavioral or physical phenotypes, and aldicarb resistant or sensitive phenotypes. Conclusion These mutants provide the opportunity for further systematic research on the active zone formation and the neurotransmission. 展开更多
关键词 genetic screen active zone formation synapse defective protein 2 forward genetics C. elegans
下载PDF
Self-assembly of hierarchical ZnSnO_3-SnO_2 nanoflakes and their gas sensing properties
12
作者 曾毅 邴一飞 +2 位作者 刘畅 郑伟涛 邹广田 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2451-2458,共8页
A new type of hierarchical ZnSnO3-SnO2 flower-shaped nanostructure composed of thin nanoflakes as secondary units is successfully prepared through a simple hydrothermal process. The polyhedral ZnSnO3 core acts as a sa... A new type of hierarchical ZnSnO3-SnO2 flower-shaped nanostructure composed of thin nanoflakes as secondary units is successfully prepared through a simple hydrothermal process. The polyhedral ZnSnO3 core acts as a sacrificed template for the growth of hierarchical SnO2 nanoflakes, and the average thickness of SnO2 nanoflakes is around 25 nm. The time-dependent morphology evolution of ZnSnO3-SnO2 samples was investigated, and a possible formation mechanism of these hierarchical structures is discussed. The gas sensor based on these novel ZnSnO3-SnO2 nanostructures exhibits high response and quick response- recovery traits to ethanol (C2H5OH). It is found that ZnSnO3-SnO2 nanoflakes have a response of 27.8 to 50×10-6 C2H5OH at the optimal operating temperature of 270 °C, and the response and recovery time are within 1.0 and 1.8 s, respectively. 展开更多
关键词 complex nanostructure hierarchical structure hydrothermal synthesis gas sensor
下载PDF
FLIGHT CLASSIFICATION MODEL BASED ON TRANSITIVE CLOSURE ALGORITHM AND APPLICATION TO FLIGHT SEQUENCING PROBLEM 被引量:3
13
作者 李雄 徐肖豪 李冬宾 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第1期31-35,共5页
A new arrival and departure flight classification method based on the transitive closure algorithm (TCA) is proposed. Firstly, the fuzzy set theory and the transitive closure algorithm are introduced. Then four diff... A new arrival and departure flight classification method based on the transitive closure algorithm (TCA) is proposed. Firstly, the fuzzy set theory and the transitive closure algorithm are introduced. Then four different factors are selected to establish the flight classification model and a method is given to calculate the delay cost for each class. Finally, the proposed method is implemented in the sequencing problems of flights in a terminal area, and results are compared with that of the traditional classification method(TCM). Results show that the new classification model is effective in reducing the expenses of flight delays, thus optimizing the sequences of arrival and departure flights, and improving the efficiency of air traffic control. 展开更多
关键词 air traffic control transitive closure algorithm cost of flight delay classification model
下载PDF
ARTIFACT CORRECTION OF RIGID TRANSLATIONAL MOTION IN MRI
14
作者 陈春晓 王世杰 +1 位作者 陶华 罗立民 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期318-321,共4页
During the process of magnetic resonance imaging (MRI), the patient motion causes phase errors in collected signals and induces motion artifacts in the reconstructed image. Severe artifacts interfere with the focus ... During the process of magnetic resonance imaging (MRI), the patient motion causes phase errors in collected signals and induces motion artifacts in the reconstructed image. Severe artifacts interfere with the focus location. Because the genetic algorithm (GA) has characteristics of parallel, random and adaptive stochastic searching, a correction method of motion artifacts is presented based on the algorithm. The method can correct the phase error in K-space signals step by step. Experiments show that the motion artifacts in MRI can be effectively suppressed by using the method. 展开更多
关键词 magnetic resonance imaging motion artifact genetic algorithm
下载PDF
NOISE EFFECT ON CHARACTERISTICS OF FLIP FLOP SENSOR
15
作者 姚素英 毛赣如 +1 位作者 曲宏伟 张维新 《Transactions of Tianjin University》 EI CAS 1998年第1期84-87,共4页
This paper presents a new class of semiconductor integrated sensor which consists of sensitive components and flip flop circuit. The sensors have high sensitivity and digital output. This paper describes the operatin... This paper presents a new class of semiconductor integrated sensor which consists of sensitive components and flip flop circuit. The sensors have high sensitivity and digital output. This paper describes the operating principle and structure of the sensor. And noise effect on characteristics of the sensor is analysed in detail. The modulated effect of the triangular wave voltage is quantified. As an example, an integrated pressure sensor is introduced and the experimental results agree with the theoretical analyses. 展开更多
关键词 flip flop sensor semiconductor integrated noise digital output
下载PDF
Analysis of Genetic Variation and Population Structure of Starch Synthesis-related Genes in Indica Rice Cultivars
16
作者 赵春芳 胡庆峰 +7 位作者 强新涛 赵凌 赵庆勇 陈涛 周丽慧 姚姝 梁文化 王才林 《Agricultural Science & Technology》 CAS 2016年第9期1993-1999,共7页
In this study, 34 molecular markers of starch synthesis-related genes were used to evaluate the genetic variation and population structure of 87 indica rice cultivars from different countries and regions. The results ... In this study, 34 molecular markers of starch synthesis-related genes were used to evaluate the genetic variation and population structure of 87 indica rice cultivars from different countries and regions. The results showed that a total of 80 alleles were amplified using 34 primer pairs, with an average of 2.5 alleles per locus. The allele number varied from 2 to 6 among various cultivars. Shannon's diversity index of molecular markers varied from 0.303 to 0.796, with an average of 0.539. Polymorphism information content (PIC) varied from 0.084 to 0.658, with an average of 0.295. The genetic similarity coefficients of 87 indica rice cultivars ranged from 0.265 to 0.990, indicating significant genetic differences of starch synthesis-related genes among different cultivars, but the variation frequency of alleles varied among different cultivars. Population structure analysis showed that these 87 indica rice cultivars were divided into three categories. Genetic differences were small within the same category but great among different categories. Moreover, indica rice cultivars with simple genetic components accounted for 39.1% and those with complex genetic background accounted for 60.9%. This study may not only provide theoretical basis for genetic improvement of rice starch quality, but also lay a solid foundation for subsequent association analysis of rice quality-related traits. 展开更多
关键词 Indica rice Starch synthesis-related gene Genetic variation Population structure
下载PDF
INTEGRATED OPERATOR GENETIC ALGORITHM FOR SOLVING MULTI-OBJECTIVE FLEXIBLE JOB-SHOP SCHEDULING
17
作者 袁坤 朱剑英 +1 位作者 鞠全勇 王有远 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第4期278-282,共5页
In the flexible job-shop scheduling problem (FJSP), each operation has to be assigned to a machine from a set of capable machines before alocating the assigned operations on all machines. To solve the multi-objectiv... In the flexible job-shop scheduling problem (FJSP), each operation has to be assigned to a machine from a set of capable machines before alocating the assigned operations on all machines. To solve the multi-objective FJSP, the Grantt graph oriented string representation (GOSR) and the basic manipulation of the genetic algorithm operator are presented. An integrated operator genetic algorithm (IOGA) and its process are described. Comparison between computational results and the latest research shows that the proposed algorithm is effective in reducing the total workload of all machines, the makespan and the critical machine workload. 展开更多
关键词 flexible job-shop integrated operator genetic algorithm multi-objective optimization job-shop scheduling
下载PDF
Present status and conservation strategies of mangrove resource in Guangdong, P. R. China 被引量:2
18
作者 韩维栋 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第2期151-154,共4页
According to the survey of Guangdong mangrove resource in 2001 and authors field investigations in the past 5 years, the total mature mangrove land area of Guangdong Province was estimated at 9084 hm2, accounting for ... According to the survey of Guangdong mangrove resource in 2001 and authors field investigations in the past 5 years, the total mature mangrove land area of Guangdong Province was estimated at 9084 hm2, accounting for 41.4% of total mangrove land area of China. These mangrove forests totally consisted of 50 species belonging to 28 families, distributed at more than 100 locations along the coastlines of Guangdong and most of them present a high dense and dwarf appearance. The Ass. Avicennia marina is the most dominant mangrove association. The investigation results showed that the mangrove forests with coverage rates above 0.7 accounted for 68.0% of the total mangrove land area of the province and 77.8% of mangrove forests was less than 2 m in tree height. Since 1950, 54.6% of mangrove forests have disappeared due to paddy rice reclaim, aquaculture and city constructions. Derivational conservation efforts are still weakly empowered and should be strengthened intensively. The author suggested that mangrove laws and regulations should be enforced, mangrove scientific research should be strengthened; and mangrove conservation awareness of local community should be raised on conservation of mangroves. 展开更多
关键词 GUANGDONG MANGROVE Present status of resource Conservation.
下载PDF
Thrombosis and inflammatory bowel disease-the role of genetic risk factors 被引量:9
19
作者 Georgia Tsiolakidou Ioannis E Koutroubakis 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第28期4440-4444,共5页
Thromboembolism is a significant cause of morbidity and mortality in patients with inflammatory bowel disease (IBD). Recent data suggest thromboembolism as a disease-specific extraintestinal manifestation of IBD, wh... Thromboembolism is a significant cause of morbidity and mortality in patients with inflammatory bowel disease (IBD). Recent data suggest thromboembolism as a disease-specific extraintestinal manifestation of IBD, which is developed as the result of multiple interactions between acquired and genetic risk factors. There is evidence indicating an imbalance of procoagulant, anticoagulant and fibrinolitic factors predisposing in thrombosis in patients with IBD. The genetic factors that have been suggested to interfere in the thrombotic manifestations of IBD include factor V Leiden, factor Ⅱ (prothrombin, G20210A), methylenetetrahydrofolate reductase gene mutation (MTHFR, 6777T, plasminogen activator inhibitor type 1 (PAI-1) gene mutation and factor X Ⅲ (val34leu). In this article we review the current data and future prospects on the role of genetic risk factors in the development of thromboembolism in TBD. 展开更多
关键词 Crohn's disease Factor Leiden GENETICS THROMBOSIS Ulcerative colitis
下载PDF
TGF-β-induced epithelial to mesenchymal transition 被引量:231
20
作者 Jian Xu Samy Lamouille Rik Derynck 《Cell Research》 SCIE CAS CSCD 2009年第2期156-172,共17页
During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation (EMT). In this process, the cells lose ... During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation (EMT). In this process, the cells lose their epithelial characteristics, including their polarity and specialized cell-cell contacts, and acquire a migratory behavior, allowing them to move away from their epithelial cell community and to integrate into surrounding tissue, even at remote locations. EMT illustrates the differentiation plasticity during development and is complemented by another process, called mesenchymal to epithelial transition (MET). While being an integral process during development, EMT is also recapitulated under pathological conditions, prominently in fibrosis and in invasion and metastasis of carcinomas. Accordingly, EMT is considered as an important step in tumor progression. TGF-β signaling has been shown to play an important role in EMT. In fact, adding TGF-β to epithelial cells in culture is a convenient way to induce EMT in various epithelial cells. Although much less characterized, epithelial plasticity can also be regulated by TGF-β-related bone morphogenetic proteins (BMPs), and BMPs have been shown to induce EMT or MET depending on the developmental context. In this review, we will discuss the induction of EMT in response to TGF-β, and focus on the under- lying signaling and transcription mechanisms. 展开更多
关键词 TGF-Β EMT SMAD TRANSCRIPTION non-Smad signaling
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部