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   1159篇
  免费   72篇
  国内免费   11篇
耳鼻咽喉   5篇
儿科学   34篇
妇产科学   6篇
基础医学   148篇
口腔科学   14篇
临床医学   120篇
内科学   350篇
皮肤病学   15篇
神经病学   59篇
特种医学   34篇
外科学   159篇
综合类   20篇
预防医学   84篇
眼科学   17篇
药学   107篇
中国医学   16篇
肿瘤学   54篇
  2023年   22篇
  2022年   42篇
  2021年   77篇
  2020年   34篇
  2019年   58篇
  2018年   65篇
  2017年   26篇
  2016年   32篇
  2015年   45篇
  2014年   60篇
  2013年   66篇
  2012年   94篇
  2011年   96篇
  2010年   36篇
  2009年   44篇
  2008年   58篇
  2007年   54篇
  2006年   55篇
  2005年   41篇
  2004年   48篇
  2003年   46篇
  2002年   27篇
  2001年   12篇
  2000年   19篇
  1999年   12篇
  1998年   3篇
  1997年   9篇
  1996年   4篇
  1995年   3篇
  1994年   6篇
  1993年   4篇
  1992年   2篇
  1991年   3篇
  1990年   5篇
  1989年   5篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   7篇
  1983年   4篇
  1980年   1篇
  1979年   1篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
排序方式: 共有1242条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
A 37-year-old Bangladeshi presented with large bilateral masses involving the hilus of the kidneys. No lymphadenopathy was noted. Nephrectomy was performed. Histopathologically, it revealed a lymphohistiocytic and plasma cell inflammatory tumoral proliferation with characteristic lymphophagocytosis by the S100-positive-CD1-negative histiocytes. Extranodal presentation of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) should be entertained in the differential diagnosis of bilateral masses involving the kidneys.  相似文献   
5.
The purpose of this study was to determine whether serum lactate dehydrogenase (LDH) level could be used as an adjunct clinical marker to differentiate between histoplasmosis and Pneumocystis carinii pneumonia (PCP). In a retrospective, case-controlled study, 30 patients with a diagnosis of histoplasmosis (all but 1 with disseminated disease) were compared with 120 patients with PCP (33 patients with definitive PCP, 87 with presumed PCP). Groups were matched for CD4+ lymphocyte counts, sex, and year of diagnosis. The mean LDH level for patients with histoplasmosis was 1068 +/- 197 IU/L; for PCP, it was 375 +/- 23. An LDH level of more than 450 IU/L was 9.33 times more likely to be associated with a diagnosis of histoplasmosis than with PCP (odds ratio [OR], 9.33; 95% confidence interval [CI], 3.50-25.47; P < .01), and an LDH level of more than 600 IU/L was 9.41 times more likely to be so (OR, 9.41; 95% CI, 3.43-26.31; P < .01). An LDH level of 450 IU/L or greater had a sensitivity and specificity of 70% and 80%, respectively; a value of 600 IU/L or greater had sensitivity and specificity of 50% and 89%. Thus, serum LDH levels of 600 IU/L or greater are suggestive of histoplasmosis rather than PCP in appropriate clinical settings. Serum LDH may serve as an adjunct laboratory marker in the diagnosis of histoplasmosis. Elevated levels may prompt the physician to look for a diagnosis other than PCP early in the course of the illness.  相似文献   
6.
Butt AA 《The AIDS reader》2003,13(7):344-348
Pancreatitis and lactic acidosis are severe and life-threatening adverse events associated with nucleoside analogue antiretroviral therapy used to treat HIV infection. The drug from this class most commonly associated with these adverse events is stavudine, although zidovudine and didanosine have also been implicated. Ribavirin is a nucleoside analogue used in combination with interferon alfa to treat hepatitis C. Because of similar mechanisms of action, the combination of these 2 drugs could potentially increase such toxicity. A case of fatal lactic acidosis and pancreatitis is described in an HIV-infected patient coinfected wtih hepatitis C on a didanosine-containing antiretroviral regimen after treatment of hepatitis C was initiated with ribavirin and pegylated interferon alfa-2b. Extreme caution should be exercised when didanosine and ribavirin are used concomitantly because of the increased risk of mitochondrial toxicity and the syndrome of severe metabolic acidosis with elevated lactic acid levels.  相似文献   
7.
Mechanisms that underlie the patterning of cytokine expression in T helper (T(H)) cell subsets remain incompletely defined. An evolutionarily conserved approximately 400-bp noncoding sequence in the intergenic region between the genes Il4 and Il13, designated conserved noncoding sequence 1 (CNS-1), was deleted in mice. The capacity to develop T(H)2 cells was compromised in vitro and in vivo in the absence of CNS-1. Despite the profound effect in T cells, mast cells from CNS-1(-/-) mice maintained their capacity to produce interleukin 4. A T cell-specific element critical for the optimal expression of type 2 cytokines may represent the evolution of a regulatory sequence exploited by adaptive immunity.  相似文献   
8.
Alliance governance is a form of governance developed in industry settings and more recently applied to healthcare. The core idea behind alliance governance is to involve the many stakeholders in the system to collaboratively develop a joint programme that promotes an integrated and whole of systems approach to care. Little is known about the model in healthcare, nor what those involved in an alliance should be focused upon. Using a modified Delphi method, this research presents a set of components that research participants agreed should underpin development of an effective alliance governance arrangement.These characteristics include a systems perspective—a truly shared governance protocol based on a shared vision and a common purpose; performance measurement—collecting and using real-time data that depicts the realities of an end-to-end system to establish better and more achievable goals based on alliance performance; a relational perspective to promote trust, respect and collaboration amongst alliance members, who historically have been competing for contracts and resources; structural changes that enable and promote a shared governance system; and, finally, equity and inclusion to ensure a diverse alliance which promotes diversity of ideas, and involvement of all stakeholders in the decision making process. This research is relevant to policymakers seeking to develop effective alliance-type arrangements as well as to those involved in the practice of alliance governance.  相似文献   
9.

Exceptional precautionary measures have been adopted to stop the transmission and control of COVID-19 through the world and Pakistan is facing lockdown in this scenario. Public loyalty to precautionary measures is affected by their knowledge, attitude, risk factors and practices (KAP) towards COVID-19. The present study was conducted among the Pakistani residents to observe the knowledge, attitude, practices and risk factors towards COVID-19 outbreak in Pakistan. A questionnaire was designed, and a cross-sectional survey was conducted among participants of the study area. Participants were asked the questions regarding knowledge, attitude, practices and risk factors towards COVID-19. Data were analyzed by SPSS and t/F test and correlation was applied among the knowledge, attitude, risk factors and practices. A total of 1060 questionnaires were received. 1004 were included while 56 were excluded. The highest representation was from Punjab province (65.6%), female (63%) and age group of 21–30 years (62.1%). Most participants were single (85%), Muslim (99.4%), Urdu speaking (45.6%) and were graduates (51.5%). Most of the participants were students (52.9%) and were from economically middle-class families (40.8%). The knowledge was positively correlated with attitude and practices whereas negatively correlated with risk factors (P?<?0.05). The attitude was negatively correlated with risk factor and positively correlated with practices. The risk factors and practices were positively correlated with each other. Health education program to improve the COVID-19 knowledge, attitude, practices and risk factors should be initiated to combat current health challenge.

  相似文献   
10.
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