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   2986篇
  免费   170篇
  国内免费   2篇
耳鼻咽喉   50篇
儿科学   125篇
妇产科学   85篇
基础医学   426篇
口腔科学   26篇
临床医学   229篇
内科学   492篇
皮肤病学   64篇
神经病学   108篇
特种医学   47篇
外科学   307篇
综合类   207篇
一般理论   4篇
预防医学   212篇
眼科学   354篇
药学   184篇
中国医学   15篇
肿瘤学   223篇
  2023年   14篇
  2022年   49篇
  2021年   103篇
  2020年   70篇
  2019年   53篇
  2018年   77篇
  2017年   40篇
  2016年   63篇
  2015年   84篇
  2014年   105篇
  2013年   144篇
  2012年   191篇
  2011年   193篇
  2010年   128篇
  2009年   79篇
  2008年   165篇
  2007年   163篇
  2006年   125篇
  2005年   131篇
  2004年   140篇
  2003年   148篇
  2002年   130篇
  2001年   89篇
  2000年   102篇
  1999年   85篇
  1998年   35篇
  1997年   16篇
  1996年   19篇
  1995年   19篇
  1994年   21篇
  1993年   11篇
  1992年   27篇
  1991年   31篇
  1990年   32篇
  1989年   20篇
  1988年   24篇
  1987年   17篇
  1986年   15篇
  1985年   14篇
  1984年   11篇
  1981年   14篇
  1980年   10篇
  1978年   8篇
  1977年   11篇
  1976年   10篇
  1975年   11篇
  1973年   11篇
  1972年   9篇
  1970年   8篇
  1968年   11篇
排序方式: 共有3158条查询结果,搜索用时 31 毫秒
51.
52.
Antral follicle count (AFC) is a reliable predictor of ovarian response to stimulation and its inter-cycle and inter-observer variability has been extensively studied on in vitro fertilization (IVF), mostly in highly selected populations within studies not originally designed for this purpose. In this retrospective cohort study, we assess the inter-cycle variation of AFC in a setting similar to that of the daily practice. We included only patients undergoing mild stimulation for intrauterine insemination (IUI). One hundred and forty-eight patients had two (62 patients, group A), three (49 patients, group B) or four (37 patients, group C) IUI cycles and AFC was measured on early follicular phase of each cycle by one of the members of the medical team within daily practice. Intra-class correlation coefficients were used to estimate variability. Inter-cycle variability rendered ICCs above 0.70 in all groups improving along with the number of cycles [Group A ICC 0.78 (95%CI 0.66–0.86), Group B ICC 0.87 (95%CI 0.80–0.92) and Group C ICC 0.91 (95%CI 0.85–0.95)]. Inter-observer variability showed a high degree of concordance with ICCs above 0.95. We provide the closest approximation to real inter-cycle and inter-observer AFC variability expected in routine clinical practice.  相似文献   
53.
Background: Stigma is a major barrier to health care access and impacts the quality of life for individuals affected by tuberculosis (TB). Assessing TB stigma is essential to addressing health disparities. However, no such instrument was available in Mexico at the time of our study. This study examined the adaptability of the TB and human immunodeficiency virus (HIV) stigma scales previously used in Thailand.Methods: The original scale, developed in English, was linguistically adapted to Spanish and administered to 217 individuals affected by TB in five states in Mexico. The TB-HIV stigma subscales were designed to assess individual and community perspectives. Additional data collected included general information and socio-demographics. Assessment of psychometric properties included basic statistical tests, evaluation of Cronbach''s alpha and factor analysis.Results: We found no significant statistical differences associated with higher stigma scores by location, age, marital status, education and stigma scores. Factor analysis did not create any new factors. Internal consistency reliability coefficients were satisfactory (Cronbach α = 0.876–0.912).Conclusion: The use of the stigma scales has implications for 1) health improvements, 2) research on stigma and health disparities, and 3) TB and HIV stigma interventions. Further research is needed to examine transferability among larger and randomly selected Spanish-speaking populations.  相似文献   
54.
Conventional antimycobacterial screening involves CFU analysis, which poses a great challenge due to slow growth of mycobacteria. Recombinant strains carrying reporter genes under the influence of constitutive promoters allow rapid and wide screening of compounds but without revealing their modes of action. Reporter strains using pathway-specific promoters provide a better alternative but allow a limited screening of compounds interfering with only a particular metabolic pathway. This reduces these strains to merely a second-line screening system, as they fail to identify even the more potent compounds if they are not inhibiting the pathway of interest. In this study, we have generated a double recombinant Mycobacterium bovis BCG strain carrying firefly and Renilla luciferase genes as two reporters under the control of a constitutive and an inducible mycobacterial promoter. The presence of dual reporters allows simultaneous expression and analysis of two reporter enzymes within a single system. The expression profile of the firefly luciferase gene, rendered by a constitutive mycobacterial promoter, coincides with the decline in bacterial growth in response to a wide range of antimycobacterial drugs, while the enhanced expression of Renilla luciferase mirrors the selective induction of the reporter gene expression as a result of pathway-specific inhibition. Thus, the double recombinant strain allows the screening of both primary and rationally synthesized antimycobacterial compounds in a single assay. The inhibiting response of drugs was monitored with a dual-luciferase reporter assay which can be easily adapted in high-throughput mode.  相似文献   
55.
56.
57.
58.
In India transmission of transfusion transmissible infections (TTI) has shown a relative decrease as a result of mandatory screening of donated blood for TTI’s. However, reducing the incidence of non infectious complications poses a major challenge, mainly due to the fact that a number of adverse reactions go unreported. Blood transfusion reaction, can be categorized based on the time interval between transfusion of blood products and the presentation of adverse reactions as acute i.e. those presenting during or within 24 h and as delayed i.e. those presenting anytime after 24 h. Transfusion reactions can further be classified as immune and non immune or infectious and non infectious based on the pathophysiology. In this retrospective study which was undertaken with an aim to determine the type and frequency of non infectious complications due to transfusion of blood and blood products recorded the incidence of febrile non hemolytic transfusion reactions (FNHTR) 51.40 %, allergic reactions 40.14 %, non immune hemolytic reactions 4.22 %, hypothermia 2.81 %, anaphylaxis 0.70 % and iron overload 0.70 %. FNHTR which was found to be the most common complication in this study can certainly be minimized, if not completely eliminated by adopting a policy of universal leucodepletion, the implementation of which solely depends on the financial and infrastructure resources available. This study also reiterates the importance of hemovigilance as a tool to improve the safety of blood transfusion.  相似文献   
59.
60.
Paraganglioma is a rare tumor in head and neck region. A 35 years male presented with huge swelling of tonsillar region occupying a large portion of oropharynx. Tumor had been dissected out transorally. HPE showed extra-adrenal paraganglioma. It is being reported because of its rare clinical presentation and unusual surgical approach.  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