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   718篇
  免费   49篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   14篇
妇产科学   18篇
基础医学   79篇
口腔科学   6篇
临床医学   81篇
内科学   174篇
皮肤病学   29篇
神经病学   70篇
特种医学   22篇
外科学   97篇
预防医学   43篇
眼科学   66篇
药学   40篇
肿瘤学   28篇
  2023年   7篇
  2022年   4篇
  2021年   23篇
  2020年   4篇
  2019年   11篇
  2018年   16篇
  2017年   15篇
  2016年   13篇
  2015年   20篇
  2014年   22篇
  2013年   29篇
  2012年   51篇
  2011年   47篇
  2010年   27篇
  2009年   38篇
  2008年   46篇
  2007年   48篇
  2006年   35篇
  2005年   37篇
  2004年   33篇
  2003年   28篇
  2002年   22篇
  2001年   12篇
  2000年   20篇
  1999年   17篇
  1998年   8篇
  1997年   7篇
  1994年   4篇
  1993年   4篇
  1992年   6篇
  1991年   3篇
  1990年   4篇
  1987年   5篇
  1986年   4篇
  1983年   3篇
  1980年   3篇
  1979年   4篇
  1978年   5篇
  1977年   5篇
  1975年   4篇
  1973年   6篇
  1972年   5篇
  1971年   5篇
  1970年   4篇
  1969年   4篇
  1967年   4篇
  1966年   3篇
  1965年   3篇
  1920年   2篇
  1914年   3篇
排序方式: 共有770条查询结果,搜索用时 156 毫秒
41.
Antimalarial activity of cyclosporin A   总被引:9,自引:0,他引:9  
Cyclosporin A has been shown to possess antimalarial activity in mice infected withPlasmodium berghei NK 65 orPlasmodium chabaudi. Significant antimalarial effects were obtained with five daily oral doses of 25 mg/kg. Cyclosporin A treatment started concurrently with the inoculation of parasites was less effective than treatment started when parasitaemia was already established. Evidence so far suggests that the antimalarial action results from a direct toxic effect on the parasite. Combined treatment with Cyclosporin A and Pyrimethamine indicated that the two compounds may act synergistically.  相似文献   
42.
The incorporation of radioactivity from tritiated glucosamine into glycoproteins was studied in Strong A male mice, with and without Ehrlich ascites tumor. The proteins studied were mouse plasma, ascites fluid, and the extracellular fluid from in vitro incubations of Ehrlich ascites tumor cells. Of particular interest in the in vivo experiments were the relatively high specific radioactivity of the γ-globulin fraction of the ascites fluid as compared to mouse plasma and that the incorporation of glucosamine-3H into the γ-globulin fraction was greatest at 90 hr following inoculation of the tumor. At 66 hr of tumor growth, the radioactivity of the ascites γ-globulin fraction was slightly greater than that of the plasma γ fraction, but it increased to 15 times that of the plasma fraction at 90 hr. Although the specific activity of the ascites γ fraction had decreased markedly by 168 hr of tumor growth, it was still four times that of the plasma fraction. A similar pattern of radioactivity incorporation was observed when Ehrlich ascites tumor cells were incubated with tritiated glucosamine in vitro. The specific activity of the γ-globulin fraction of the extracellular fluid, following incubation with Ehrlich ascites tumor cells obtained from 90 hr of tumor growth, was more than twice that observed with cells from 66 or 168 hr of tumor growth.  相似文献   
43.
Mutations in superoxide dismutase cause a subset of familial amyotrophic lateral sclerosis and provoke progressive paralysis when expressed in mice. After retrograde transport to the spinal cord following injection into muscles, an adeno-associated virus carrying a gene that encodes a small interfering RNA was shown to target superoxide dismutase messenger RNA for degradation. The corresponding decrease in mutant superoxide dismutase in spinal motor neurons preserved grip strength. This finding provides proof of principle for the selective reduction of any neuronal protein and supports intramuscular injections of a small interfering RNA-encoding virus as a viable therapy for this type of familial amyotrophic lateral sclerosis.  相似文献   
44.
45.
46.
Functional mapping of GABA A receptor subtypes in the amygdala   总被引:2,自引:0,他引:2  
The physiological significance of the large diversity of GABA A receptors is poorly understood. Using mice, which carry a point mutation that renders specific subtypes of GABA A receptors diazepam insensitive, it was recently discovered that particular types of GABA A receptors are involved in specific, behaviorally relevant signaling pathways. We have used these mice to study inhibitory synaptic transmission in the amygdala. GABA A receptor-mediated inhibitory postsynaptic currents (IPSCs) per se were not affected by the point mutations. Their modulation by diazepam, however, was altered depending on the genotype of the mice studied. Based on the different responses to diazepam, we found that IPSCs in the lateral/basolateral amygdala were mediated by both alpha2- and alpha1-subunit-containing GABA A receptors whereas those in the central amygdala were mediated only by alpha2-subunit-containing GABA A receptors. Immunohistochemical staining corroborated these findings at a morphological level. To investigate a possible link between interneuron and receptor diversity, we selectively depressed release from the subset of GABAergic terminals carrying type 1 cannabinoid receptors. These receptors are known to modulate amygdala-mediated behavior. Application of a type 1 cannabinoid receptor agonist resulted in a selective reduction of inhibitory current mediated by alpha1-subunit-containing GABA A receptors. Mice with specific diazepam-insensitive GABA A receptor subtypes therefore provide a novel tool to investigate GABA A receptor distribution and the organization of inhibitory circuits at a functional level. The crucial role of the amygdala for the mediation of anxiety is in agreement with the part that alpha2-subunit-containing GABA A receptors play in anxiolysis and their important function in this area of the brain.  相似文献   
47.
HYPOTHESIS: Advances in specialized centers for pancreatic diseases have improved surgical morbidity and outcome. In the past, postoperative local complications (pancreatic fistulae) were causing most of the mortality. Now, more patients experience postoperative complications related to their comorbidity. DESIGN: To report a prospective audit of a single center's experience with pancreatic resection during an 8-year period. SETTING: Tertiary referral center focused on pancreatic diseases. PATIENTS AND INTERVENTIONS: Six hundred seventeen consecutive patients underwent pancreatectomy between November 1, 1993, and August 31, 2001. The series included 468 pancreatic head resections (76%), 25 total pancreatectomies (4%), 88 left-sided resections (14%), and 36 others (6%). MAIN OUTCOME MEASURES: Morbidity after pancreatic resection. RESULTS: Postoperative in-hospital mortality was 1.6%, and the additional operation rate was 4.1%. Four patients died of surgical complications and 6 of systemic complications. Systemic morbidity was 18% and consisted primarily of cardiopulmonary complications (13%). The most frequent postoperative complication was delayed gastric emptying (14%), which caused significant prolongation of the hospital stay. No patients died of a postoperative pancreatic fistula, which occurred in 3.2%, and no completion pancreatectomies were necessary. CONCLUSIONS: Pancreatic resections can be performed with considerable safety and a low rate of pancreatic complications. More patients die of systemic complications than in the past, which increases the demand for precise preoperative patient selection. Completion pancreatectomy should no longer be considered in patients with a pancreatic fistula.  相似文献   
48.
At the 4th Austrian SIDS Consensus Meeting (1998), consultation was the focus of attention. Secure sleep, the Vienna SIDS prevention campaign, is an information campaign in cooperation with the children's hospitals of Vienna with the aim of reducing the incidence of SIDS in and around Vienna. The campaign was intended to spread awareness concerning care measures to reduce SIDS as well as to reduce SIDS related anxiety (SRA) among anxious parents. The Vienna SIDS prevention campaign is a quality management project, the core of which is consultation. Demands upon the structural quality of a SIDS consultation office include the expertise, communication skills and psychological competence of the consulting team. This can be achieved through interdisciplinary continuing education, international networking and training in communication skills. Priority is given to supporting care for the client by an interdisciplinary team headed by a case manager with the required communication skills. The qualitative outcome is defined by a primary objective medical goal (reduction of SIDS mortality) and a secondary subjective psychological goal (reduction of SRA). It also includes raising effectiveness and efficiency through optimal consultation and, finally, reducing costs by saving expenditure for monitors. The quality of SIDS consultation can be measured by evaluating satisfaction in patients as well as among co-workers.  相似文献   
49.
Resümee Ein Cylindrom am Ende eines freien Meckelschen Divertikels, ein Tumor, der am Darm erst einmal, am Meckelschen Divertikel noch nicht beobachtet wurde, hat durch Abknickung des Darmanhanges zu Diverticulitis, Perforation und sog. gedoppelter Invagination des Ileum geführt.  相似文献   
50.
Background: The QT intervals accuracy for predicting arrhvthmic death varies between studies, possibly due to differences in the selection of the lead used for measurement of the QT interval. The purpose of this study was to analyze the prognostic accuracy of all known ways to select the lead. Methods and Results: Three institutions that used different methods for measuring QT intervals provided their QT databases. They included more than 3500 twelve‐lead surface ECGs. The data represented low‐ and high‐risk patients of the normal population (survivors vs dead from cardiovascular causes), acute myocardial infarction (survivors versus death from all causes) and remote myocardial infarction (with vs without a history of ventricular arrhythmia). The prognostic accuracy was defined as the area under the Receiver Operator Curve (ROC‐area). The most accurate standard leads were I and aVL and the least accurate was AVR. The most accurate precordial lead was V4. The prognostic accuracy of the longest QT interval was higher than for any standard lead. The prognostic accuracv of the mean of the three longest QT intervals was equal to or slightly lower than for the longest QT interval. Conclusions: The highest prognostic accuracy is obtained with the longest QT interval. The accuracies of the lead selection methods are so different that it can explain a substantial part of the differences between otherwise similar studies in the literature. We recommend the use of the mean value of the three longest QT intervals. A.N.E. 2002;7(1):10–16  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