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   1551篇
  免费   71篇
  国内免费   11篇
耳鼻咽喉   9篇
儿科学   93篇
妇产科学   103篇
基础医学   119篇
口腔科学   42篇
临床医学   171篇
内科学   321篇
皮肤病学   45篇
神经病学   25篇
特种医学   145篇
外科学   119篇
综合类   138篇
预防医学   93篇
眼科学   10篇
药学   90篇
  1篇
中国医学   74篇
肿瘤学   35篇
  2021年   15篇
  2020年   10篇
  2018年   13篇
  2017年   18篇
  2016年   15篇
  2015年   34篇
  2014年   44篇
  2013年   42篇
  2012年   49篇
  2011年   46篇
  2010年   55篇
  2009年   45篇
  2008年   43篇
  2007年   38篇
  2006年   36篇
  2005年   18篇
  2004年   17篇
  2003年   12篇
  2002年   11篇
  2001年   20篇
  2000年   10篇
  1999年   20篇
  1998年   43篇
  1997年   54篇
  1996年   47篇
  1995年   42篇
  1994年   55篇
  1993年   35篇
  1992年   15篇
  1991年   14篇
  1990年   14篇
  1989年   28篇
  1988年   27篇
  1987年   30篇
  1986年   25篇
  1985年   16篇
  1984年   16篇
  1983年   16篇
  1982年   13篇
  1981年   23篇
  1980年   16篇
  1959年   35篇
  1958年   58篇
  1957年   87篇
  1956年   45篇
  1955年   75篇
  1954年   67篇
  1953年   17篇
  1952年   14篇
  1949年   10篇
排序方式: 共有1633条查询结果,搜索用时 15 毫秒
91.
The left ventricular diastolic filling pattern in congestive cardiomyopathy is heterogeneous and may vary from a "rapid filling predominant pattern" to an "atrial filling predominant pattern." The observed pattern of diastolic filling may depend on a complex interaction of factors including: left ventricular relaxation, left ventricular stiffness, external constraining forces, loading conditions, and heart rate. These factors appear to express themselves individually and collectively through alterations in the time course and extent of the transmitral pressure gradient. In this review, the physiological basis for each of these diastolic filling patterns is discussed based on previous clinical and experimental studies that either directly or indirectly address these issues. (ECHOCARDIOGRAPHY, Volume 8, March 1991)  相似文献   
92.
93.
A case of postinfarction left ventricular free wall rupture is successfully treated. Prompt diagnosis was provided by echocardiography and an emergency operation was carried out. Following sternotomy, hemodynamic stabilization was obtained by gradually evacuating blood from the pericardium, while the femoral vessels were cannulated and the extracorporeal circulation was established. An autologous glutaraldehyde stiffened pericardial patch was sealed over the infarcted area using fibrin glue and fixed with a running suture on the surrounding healthy myocardium.  相似文献   
94.
A new variant of congenital hemolyticanemia associated with stomatocytosis,reticulocytosis, decreased osmotic fragility, type I autohemolysis and shortened erythrocyte survival without specific splenic sequestration was discoveredin three siblings of Swiss-German ancestry. Increased intracellular sodium(two to three times normal) and slightlydecreased intracellular potassium weredetected. Total sodium efflux was eight-fold greater than normal but total potassium influx was normal and ouabain-sensitive potassium influx was decreased.The ouabain-sensitive sodium efflux:potassium influx ratio was 26:1 ratherthan the 3:2 ratio noted in normal cells.The consanguineous parents, four othersiblings, and 44 other family membershad mild stomatocytosis, reticulocytosis,and, when studied, decreased osmoticfragility, increased autohemolysis, intermediate abnormalities of cation content,cation flux, and moderate shortening oferythrocyte survival. Autosomal dominant inheritance was suggested. Noabnormalities of RBC enzymes, hemoglobin or lipids were observed. No abnormalities of membrane protein weredetected on acrylamide gel. Substratedepletion of these hypermetabolic cellsresulted in intracellular dehydrationwith potassium loss in excess of sodiumgain and decreased deformability. Although the exact nature of the defectresponsible for hemolysis is unknown,this syndrome differs from other hereditary hemolytic anemias associated withstomatocytosis.

Submitted on December 21, 1970 Revised on March 16, 1971 Accepted on March 29, 1971  相似文献   
95.
Vora  S; Wims  LA; Durham  S; Morrison  SL 《Blood》1981,58(4):823-829
Recently we have demonstrated that human phosphofructokinase (PFK; ATP: D-fructose-6-P, 1-phosphotransferase; EC.2.7.1.11) is under the control of three structural loci that code for M (muscle-type), L (liver-type), and P (platelet-type) subunits: random tetramerization of these subunits produces various isozymes. In this study, we have produced and characterized BALB/c hybridoma antibodies to the M- and L-type subunits of human PFK. The specific antibodies were detected by an enzyme- immunoprecipitation assay using Staphylococci-bearing protein A as an immunoadsorbent. Of the wells tested using red blood cell (RBC) PFK (M + L), 61% were positive. Only one M-specific hybridoma was identified. The one anti-M and 4 anti-L antibodies were characterized for their biochemical and immunochemical specificities. To define the combining specificities of these antibodies, we compared their reactivity and that of monospecific rabbit anti-M antiserum with muscle and liver PFKs from 15 different vertebrate species. The rabbit anti-M shows strong cross-reactivity with the muscle PFKs from all the species studied. In contrast, the monoclonal anti-M reacts exclusively with muscle PFKs from primates. Two of four anti-L antibodies react only with human L- PFK, whereas the other two react with that from a few other vertebrate species as well. Taken together, these data suggest that primate- specific antibodies recognize evolutionarily, recently acquired antigenic determinants, whereas the antibodies reactive with PFKs from distantly related species recognize conserved determinants. The differential immunoreactivities of muscle and liver PFKs strongly suggest the presence of distinct isozymes in all the vertebrate species studied. These studies demonstrate that it is feasible to produce and characterize monoclonal antibodies that distinguish among isozymes with structural and functional similarities. These antibodies provide sensitive tools in the analyses of isozyme structure, genetics, and related fields.  相似文献   
96.
Farese  AM; Myers  LA; MacVittie  TJ 《Blood》1994,84(11):3675-3678
The therapeutic efficacy of recombinant human leukemia inhibitory factor (LIF) was examined in a nonhuman primate model of radiation- induced marrow aplasia. Rhesus monkeys received 450 cGy of total-body, 1:1 mixed neutron:gamma radiation. For 23 days thereafter, each monkey received a daily subcutaneous injection of LIF or human serum albumin (HSA) at a dose of 15 micrograms/kg body weight. Complete blood counts and white blood cell differentials were monitored for 60 days postirradiation. Administration of LIF significantly decreased (P < or = .05) the duration of thrombocytopenia (platelet count < 30,000 or 20,000/microL), ie, 9.3 days or 6.3 days, respectively, versus the HSA- treated control monkeys, 12.2 days or 10.2 days, respectively. Treatment with LIF did not alter the duration of neutropenia (absolute neutrophil count < 1,000/microL) as compared with the HSA-treated control monkeys. Cytokine administration did not exacerbate the radiation-induced anemia observed in the HSA-treated control monkeys.  相似文献   
97.
98.
99.
100.
Milia en plaque     
Summary A 59-year-old woman presented with milia grouped in plaques, in the preauricular areas, bilaterally. Follicle-damaging dermatoses, tumours and external agents, can lead to this peculiar clinical pattern. We outline the clinical and histological features which allow accurate diagnosis of this condition.  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