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   5830篇
  免费   446篇
  国内免费   35篇
耳鼻咽喉   55篇
儿科学   249篇
妇产科学   107篇
基础医学   766篇
口腔科学   112篇
临床医学   766篇
内科学   1083篇
皮肤病学   75篇
神经病学   517篇
特种医学   471篇
外科学   542篇
综合类   128篇
一般理论   5篇
预防医学   568篇
眼科学   83篇
药学   413篇
  1篇
中国医学   7篇
肿瘤学   363篇
  2022年   31篇
  2021年   96篇
  2020年   49篇
  2019年   95篇
  2018年   114篇
  2017年   81篇
  2016年   91篇
  2015年   108篇
  2014年   141篇
  2013年   202篇
  2012年   247篇
  2011年   267篇
  2010年   170篇
  2009年   188篇
  2008年   240篇
  2007年   275篇
  2006年   247篇
  2005年   247篇
  2004年   239篇
  2003年   206篇
  2002年   190篇
  2001年   155篇
  2000年   144篇
  1999年   164篇
  1998年   138篇
  1997年   162篇
  1996年   142篇
  1995年   112篇
  1994年   114篇
  1993年   117篇
  1992年   110篇
  1991年   102篇
  1990年   93篇
  1989年   108篇
  1988年   101篇
  1987年   83篇
  1986年   95篇
  1985年   100篇
  1984年   53篇
  1983年   57篇
  1982年   42篇
  1981年   58篇
  1980年   52篇
  1979年   46篇
  1978年   38篇
  1977年   41篇
  1976年   39篇
  1975年   29篇
  1974年   31篇
  1972年   31篇
排序方式: 共有6311条查询结果,搜索用时 31 毫秒
91.
92.
Two juvenile pigtailed macaques (animals 1 and 2) received total body irradiation (TBI) followed by autologous stem cell transplantation, by a procedure known to be well tolerated by baboons. In this procedure, the TBI consisted of treatment on two consecutive days with 255cGy on one side, followed after 1-2 min by a similar dose on the other side. The two pigtailed macaques showed rapid haematopoietic engraftment, but succumbed either to systemic cytomegalovirus (CMV) infection and necrotising colitis or to haemorrhagic cystitis and tubulointerstitial nephritis. For four further pigtailed macaques (animals 3-6) the radiation procedure was changed to four equal doses of 255cGy, given 6-12 h apart. Animals 4-6 all showed engraftment and survived for long periods (>218 days), with no, or only minor treatable, complications. Animal 3 failed to show engraftment and succumbed to radiation-induced vascular lesions and severe multiorgan haemorrhages. The results suggest that pigtailed macaques have a lower tolerance threshold than baboons, rhesus macaques or human beings to TBI, the adverse effects of TBI being indistinguishable from those seen in human patients. The results also suggest that a hyperfractionated radiation procedure can prevent radiation-induced morbidity and mortality in pigtailed macaques.  相似文献   
93.
K A Kelley  P M Pitha 《Virology》1985,147(2):382-393
The expression of type I murine interferon (MuIFN) genes and several other cellular genes was examined in poly rI.rC induced and Newcastle disease virus (NDV) infected mouse cells. Northern analysis of RNA from induced L cells revealed that the MuIFN-alpha s are expressed efficiently in NDV infected cells but only at low levels in poly rI.rC induced cells. MuIFN-beta 1, however, is expressed equally well in cells treated with poly rI.rC or infected with NDV. As shown by the use of a probe specific for poly rI.rC, interferon induction correlates with the cellular uptake of poly rI.rC into the cells. The relative levels of alpha and beta 1 mRNAs in the cells reached a maximum at 10 hr after the induction which indicates coordinate expression of alpha and beta 1 interferon genes. The effect of viral infection on the expression of two murine genes coinduced with interferon (pMIF20/11 and pMIF3/10) and several cellular genes was also examined. While pMIF20/11 is an inducible gene, the pMIF3/10 gene is expressed constitutively in mouse L cells. Viral infection, but not poly rI.rC treatment, enhanced the expression of the pMIF3/10 gene, as well as two other cellular genes; H-2 and c-myc, however, the expression of beta-actin gene was unaltered. These data indicate that enhancement of gene expression in virus infected cells in not limited to the interferon system.  相似文献   
94.
Married or cohabiting female drug-abusing patients (N = 75) were randomly assigned to either a behavioral couples therapy condition (BCT; n = 37), which consisted of group, individual, and behavioral couples therapy sessions, or to an equally intensive individual-based treatment condition (IBT; n = 38), which consisted of group and individual counseling. During most of the 1-year follow-up, compared with participants who received IBT, those who received BCT reported (a) fewer days of substance use, (b) longer periods of continuous abstinence, (c) lower levels of alcohol, drug, and family problems, and (d) higher relationship satisfaction. However, differences in relationship satisfaction and number of days of substance use dissipated over the course of the posttreatment follow-up period and were not significantly different by the end of 1 year.  相似文献   
95.
96.
BackgroundMinimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.MethodsTwo low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017–December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.ResultsOf all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5–3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).ConclusionThese readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.Type of studyProspective study.Level of evidenceLevel II.  相似文献   
97.
Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.  相似文献   
98.

Community health workers (CHWs) serve as the linkage between community and providers and are stakeholders for bridging services to the public. However, integration of CHWs into health care organizations is often lacking. This study explored macrosystem level barriers faced by CHWs and their ability to do their jobs effectively. Using qualitative interviews from CHWs (n?=?28) in Nebraska, we used an abductive approach to derive the following themes: (1) CHWs and client macrosystem barriers, (2) CHW workforce supports, and (3) macrosystem solutions for CHW workforce sustainability. Study results also found various macrosystem barriers affecting CHW workforces including immigration policies, insurance policies, funding sources, supervisor support, and obstacles for health seeking of clients. Moreover, through the lens of CHWs, results revealed the need to provide and advocate for solutions that prioritize the needs of CHWs as they continue to fill a crucial gap in community healthcare systems.

  相似文献   
99.
100.
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