首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   565篇
  免费   17篇
  国内免费   1篇
耳鼻咽喉   5篇
儿科学   61篇
妇产科学   6篇
基础医学   75篇
口腔科学   13篇
临床医学   22篇
内科学   111篇
神经病学   13篇
特种医学   7篇
外科学   83篇
综合类   13篇
预防医学   86篇
眼科学   6篇
药学   45篇
中国医学   6篇
肿瘤学   31篇
  2022年   12篇
  2021年   13篇
  2020年   5篇
  2019年   12篇
  2018年   15篇
  2017年   9篇
  2016年   20篇
  2015年   20篇
  2014年   31篇
  2013年   45篇
  2012年   58篇
  2011年   48篇
  2010年   29篇
  2009年   21篇
  2008年   39篇
  2007年   41篇
  2006年   27篇
  2005年   32篇
  2004年   27篇
  2003年   13篇
  2002年   10篇
  2001年   17篇
  2000年   12篇
  1999年   5篇
  1998年   4篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1988年   5篇
  1983年   1篇
  1981年   1篇
  1979年   1篇
  1977年   1篇
  1972年   1篇
  1965年   1篇
排序方式: 共有583条查询结果,搜索用时 0 毫秒
81.

Background

In the world of technology, when today's student is approaching the on-line /distance learning in the open universities and doing on-line self-assessment, the classroom learning is vanishing slowly. Globally, teachers are taking efforts to improve the pedagogy by implementing effective methods to retain the classroom teaching and student attendance. The present study aims at shedding some light on the need of changing the adult education strategies (andragogy), which can effectively improve the student attendance for lectures.

Methods

It is an observational study, and the conceptual framework of it is based on beliefs, opinions and personal experiences of the respondents. Triangulation method is used for collecting the data. The data is achieved from three groups of concerned population who could provide valid results to support the study. It is collected by interviewing 10 senior faculty members who are/were the 'education experts' in the universities, while the main concerned groups of present educational stream, i.e. 'institution-teachers' and the 'students', were given questionnaires. 570 teacher respondents and 200 student respondents are the main participants of this study.

Results

As per data, it has been observed that senior faculty (90%) and students (93.25%) feel need of student motivation more than the institutional teachers (52.44%). P-values were obtained using Chi-Square test for testing the significance of difference between agreement and disagreement for a specific question.

Conclusions

In India, Universities have already sensed the need of 'teacher development programmes'. But teachers in dental colleges, demand more efforts to be taken by universities and managements in this regard and expect better educational policies to give them accessibility to prove themselves.
  相似文献   
82.
83.
84.
Genetic variability and environmental factors may influence the refractiveness, propagation of pathogen and transmission of disease. Random amplified polymorphic DNA (RAPD) is one of the widely used molecular markers for population genetic diversity studies. In present study, RAPD is used to ascertain the genetic variability in Culex quinquefasciatus populations collected from various Indian geographical locations. Out of 50 RAPD primers screened, 14 primers exhibited clear, concrete and distinct banding pattern showing up to 100% polymorphism. Primer OPBD3 was tested with DNA of 14 geographical populations from India (including one laboratory population) showed 21 loci representing 14 populations with 100% polymorphism. The genetic diversity among the populations indicated the Shannon index (I) and gene diversity index (HST), 0.48 and 0.31, respectively among the population, displaying rich genetic variation among the Cx. quinquefasciatus populations. Consensus tree showed two clusters indicating the genetic variation among the various geographical populations. The findings of this study may be useful to understand the population variation under different ecological conditions and development of effective vector management strategies.  相似文献   
85.
The directly compressible floating-bioadhesive tablets of tramadol were formulated using varying amounts Carbopol 971P (CP) and hydroxy-propylmethyl cellulose (HPMC), along with other requisite excipients. In vitro drug release profile, floatational characteristics and ex vivo bioadhesive strength using texture analyzer were determined, and systematically optimized using a 32 central composite design (CCD). The studies indicated successful formulation of gastroretentive compressed matrices with excellent controlled release, mucoadhesion and hydrodynamic balance. Comparison of the dissolution profiles of the optimized formulation, with optimal composition of CP:HPMC :: 80.0:125.0, with that of the marketed controlled release formulation other indicated analogy of drug release performance with each other. Validation of optimization study using eight confirmatory experimental runs indicated very high degree of prognostic ability of CCD with mean ± SEM of −0.06% ± 0.37. Further, the study successfully unravels the effect of the polymers on the selected response variables.  相似文献   
86.
Bovine tuberculosis caused by the bacterium Mycobacterium bovis is a major infectious disease of animals and has zoonotic importance for humans. Even though the incidence is believed to be very low in India, human tuberculosis caused by M. bovis has been increasingly recognized in many other countries of the world. As differentiation of mycobacterial species take long time, a method for the rapid identification of mycobacteria isolated from bovine samples to the species level was used, which is based on polymerase chain reaction (PCR) of the gene encoding for the 65-kD protein followed by restriction analysis. The method involves restriction enzyme analysis of PCR products obtained with primers common to all mycobacteria and generate M. tuberculosis complex specific pattern. PRA was performed on 33 bovine isolates of which 90.9% (30/33) isolates were identified clearly as M. tuberculosis complex, M. fortuitum, M. phlei and M. smegmatis using restriction enzyme Hae III.  相似文献   
87.
88.
Epigenetic dysregulation has emerged as a major contributor to tumorigenesis. Histone methylation is a well-established mechanism of epigenetic regulation that is dynamically modulated by histone methyltransferases and demethylases. The pathogenic role of histone methylation modifiers in non–small cell lung cancer (NSCLC), which is the leading cause of cancer deaths worldwide, remains largely unknown. Here, we found that the histone H3 lysine 36 (H3K36) demethylase KDM2A (also called FBXL11 and JHDM1A) is frequently overexpressed in NSCLC tumors and cell lines. KDM2A and its catalytic activity were required for in vitro proliferation and invasion of KDM2A-overexpressing NSCLC cells. KDM2A overexpression in NSCLC cells with low KDM2A levels increased cell proliferation and invasiveness. KDM2A knockdown abrogated tumor growth and invasive abilities of NSCLC cells in mouse xenograft models. We identified dual-specificity phosphatase 3 (DUSP3) as a key KDM2A target gene and found that DUSP3 dephosphorylates ERK1/2 in NSCLC cells. KDM2A activated ERK1/2 through epigenetic repression of DUSP3 expression via demethylation of dimethylated H3K36 at the DUSP3 locus. High KDM2A levels correlated with poor prognosis in NSCLC patients. These findings uncover an unexpected role for a histone methylation modifier in activating ERK1/2 in lung tumorigenesis and metastasis, suggesting that KDM2A may be a promising therapeutic target in NSCLC.  相似文献   
89.
Hepatitis C virus (HCV) is a devastating human pathogen, yet there is no vaccine available for this virus. From studies with acute or chronic HCV-infected humans and chimpanzees, T-cell responses against HCV-derived conserved non-structural antigens have been correlated with viral clearance. In this study, recombinant adenoviral vectors containing HCV-derived NS4, NS5a or NS5b genes were employed to endogenously express the HCV antigens in human dendritic cells (DCs). The DCs expressing these HCV antigens exhibited normal phenotype and function. Intriguingly, we found that the DCs expressing HCV NS4, NS5a or NS5b antigens were able to significantly stimulate autologous T cells obtained from uninfected healthy individuals. These T cells produced various cytokines and proliferated in an HCV antigen-dependent manner. Evidence of both CD4(+) and CD8(+) T-cell responses generated in vitro against HCV NS4, NS5a or NS5b were obtained. HCV NS4 was much less stimulatory for CD4(+) and CD8(+) T cells than NS5. Further, in secondary assays, the CD4(+) T cells primed in vitro exhibited HCV antigen-specific proliferative responses against recombinant protein antigens. In summary, we provide conclusive evidence of in vitro stimulation of CD4(+) and CD8(+) T cells from HCV-naive individuals against HCV antigens NS4, NS5a and NS5b. The studies with naive T cells represent early events in the induction of cellular immune responses, which most likely govern the outcome of HCV infection. These studies have significant implications in designing vaccines for HCV infection in both prophylactic and therapeutic settings.  相似文献   
90.

Introduction

Rotavirus vaccine was introduced in Mauritania in December 2014. We investigated hospitalizations with diarrhea during pre and post-vaccination periods among children aged 0–5?years in Nouakchott, the capital of Mauritania.

Methods

We conducted a retrospective review of hospital admission registries from November 1st 2012 through October 31th 2017 at all referral hospitals in Nouakchott. We described admissions of children aged 0–5?years by diagnosis, data of admission, age and sex, and compared the proportion of all childhood hospitalizations with diarrhea before and after rotavirus vaccine introduction.

Results

In total, 6552 (19%) of all 34,329 hospitalizations in 0–5?year-olds had diarrhea. Of these, 3523/16,952 (20.7%) were recorded during the pre-vaccine period, 1373/6897 (19.9%) during the transition period (November 2014-October 2015), and 1656/10,480 (15.8%) during the post-vaccination period. The proportion of all childhood hospitalizations with diarrhea during the pre-vaccine period was 22.6% among males and 18.7% among females. Approximately one third (32.3%) of hospitalizations with diarrhea occurred in children aged 6–11?months. During the post-vaccination period, the proportion of hospitalizations with diarrhea declined by 24%, and the highest reduction (74%) was observed in children aged 2 to 5?years (P?<?0.001).

Conclusions

The proportion of childhood hospitalizations with diarrhea in Nouakchott was reduced by about one fourth after introduction of rotavirus vaccination in Mauritania, indicating a major impact for public health for children in the capital city.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号