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   33084篇
  免费   2694篇
  国内免费   221篇
耳鼻咽喉   334篇
儿科学   1171篇
妇产科学   730篇
基础医学   3756篇
口腔科学   682篇
临床医学   3201篇
内科学   6926篇
皮肤病学   590篇
神经病学   2460篇
特种医学   1290篇
外科学   4971篇
综合类   1010篇
一般理论   14篇
预防医学   2200篇
眼科学   1324篇
药学   2438篇
  3篇
中国医学   163篇
肿瘤学   2736篇
  2023年   226篇
  2022年   374篇
  2021年   769篇
  2020年   501篇
  2019年   703篇
  2018年   820篇
  2017年   589篇
  2016年   675篇
  2015年   783篇
  2014年   1076篇
  2013年   1283篇
  2012年   2060篇
  2011年   2126篇
  2010年   1268篇
  2009年   1129篇
  2008年   1853篇
  2007年   1814篇
  2006年   1695篇
  2005年   1593篇
  2004年   1595篇
  2003年   1417篇
  2002年   1266篇
  2001年   1165篇
  2000年   1050篇
  1999年   904篇
  1998年   388篇
  1997年   311篇
  1996年   284篇
  1995年   280篇
  1994年   230篇
  1993年   217篇
  1992年   526篇
  1991年   498篇
  1990年   452篇
  1989年   432篇
  1988年   404篇
  1987年   375篇
  1986年   360篇
  1985年   359篇
  1984年   241篇
  1983年   230篇
  1982年   156篇
  1981年   116篇
  1980年   127篇
  1979年   166篇
  1978年   106篇
  1977年   118篇
  1976年   84篇
  1974年   86篇
  1973年   74篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Tumor necrosis factor (TNF) was produced in mice bearing Ehrlich ascites tumor (EAT) by priming with zymosan and subsequently challenging with lipopolysaccharide. The optimal conditions for the in vivo production of TNF in treating EAT bearing mice were established. The endotoxin shock induced in mice during TNF production could be minimized by the combined administration of sulindac and mannoheptulose. The endogenous TNF produced could suppress proliferation of EAT cells as well as prolong the survival time of mice bearing small tumors.  相似文献   
32.
Seven patients with systemic lupus erythematosus (SLE), persistent thrombocytopenia (TP), in whom it was considered undesirable to institute an increase in steroid or immunosuppressive agents, were treated with danazol. Five patients completed the minimum period of 8 weeks. Two patients showed early response to danazol but were switched over to cyclophosphamide or azathioprine after 4 weeks because of systemic disease. Of the remaining five patients, four had complete responses. In one patient who failed treatment the TP was considered to be related to another drug (ranitidine). Other manifestations of SLE also improved with treatment. Side effects included amenorrhea in one patient, and hypoglycemia and hyponatremia in another. Infections were absent. Danazol can be a useful alternative treatment of lupus TP.  相似文献   
33.
This paper documents the type, frequency and duration of complications associated with regional anaesthesia of the maxillary nerve via the greater palatine canal in a series of 101 patients treated in the Oral Surgery Department, United Dental Hospital of Sydney.  相似文献   
34.
Smooth muscle relaxant effect of dehydroindicolactone   总被引:1,自引:0,他引:1  
Dehydroindicolactone, a novel linear furanocoumarin with an 8-substituted side chain carrying a 5-member ring lactone, showed spasmolytic activity in a number of smooth muscle preparations. The spasmolytic activity seems to lie in its ability to block the dihydropyridine-sensitive calcium channel.  相似文献   
35.
4 cases of syringomyelia with type I Arnold Chiari malformation was seen presenting mainly with dissociated sensory loss, weakness of hands and upper motor neurone signs in the lower limbs. The first patient improved with posterior fossa decompression. The second and fourth patient appeared not to have improved after surgery, and the third case refused operation. One patient showed cord atrophy on myelogram presumably due to a collapse of the syrinx. One of the patients was unusual in that the syrinx extended down to segment T11. Magnetic resonance imaging of the posterior fossa and the cervical cord, to date, is the most useful procedure for diagnosis.  相似文献   
36.
Twenty-four nonsmoking male volunteers took 50 mg atenolol or 10 mg betaxolol orally once a day for 9 days in a two-period, four-sequence, randomized, crossover study. Plasma concentrations reached steady state after day 5. Percent fluctuation in plasma concentration defined as (Cmax-Cmin)/Cavg (% fluctuation 1) was 97% on day 9 for betaxolol and 343% for atenolol; thus atenolol fluctuation was more than threefold that of betaxolol. A 10-fold difference in plasma level fluctuation was observed when fluctuation was defined as (Cmax-Cmin)/Cmin (% fluctuation 2). The intersubject variances for % fluctuation 1 and % fluctuation 2 were 4.1 and 85.5 times greater for atenolol than for betaxolol; these differences were marginally statistically significant for % fluctuation 1 and significant for % fluctuation 2. The intrasubject variabilities for area under the curve and plasma level fluctuations were statistically greater for atenolol than for betaxolol. Atenolol intrasubject variances were 25 and 271 times greater than for betaxolol for % fluctuation 1 and % fluctuation 2, respectively. Thus, betaxolol exhibited less fluctuation in plasma levels with substantially less intersubject and intrasubject variability. These factors would be expected to provide a more consistent therapeutic response and more dependable dosage adjustment.  相似文献   
37.
38.
A 49-year-old Chinese male with spontaneous intracerebral haemorrhage due to cerebral amyloid angiopathy is presented. This is the first case reported in the Chinese population, and the youngest patient described without a family history or associated mental disorder.  相似文献   
39.
Coagulase negative staphylococci have long been thought to be harmless skin commensals. However they are now recognised as important pathogens in patients who have undergone insertion of prosthetic devices. We present three patients with infection following the insertion of silicone polymer prostheses, in whom a coagulase negative staphylococcus was the pathogen. All responded to antibiotic treatment. It is important to alert the bacteriologist to the presence of an implanted prosthesis when wound swabs are sent from an area showing clinical signs of infection. The coagulase negative staphylococci may otherwise be regarded falsely as merely skin contaminants.  相似文献   
40.
We measured CBF and the CMRglc in normal controls and in patients with severe liver disease and evidence for minimal hepatic encephalopathy using positron emission tomography. Regions were defined in frontal, temporal, parietal, and visual cortex; the thalamus; the caudate; the cerebellum; and the white matter along with a whole-slice value obtained at the level of the thalamus. There was no difference in whole-slice CBF and CMRglc values. Individual regional values were normalized to the whole-slice value and subjected to a two-way repeated measures analysis of variance. When normalized CBF and CMRglc values for regions were compared between groups, significant differences were demonstrated (F = 5.650, p = 0.00014 and F = 4.58, p = 0.0073, respectively). These pattern differences were due to higher CBF and CMRglc in the cerebellum, thalamus, and caudate in patients and lower values in the cortex. Standardized coefficients extracted from a discriminant function analysis permitted correct group assignment for 95.5% of the CBF studies and for 92.9% of the CMRglc studies. The similarity of the altered pattern of cerebral metabolism and flow in our patients to that seen in rats subjected to portacaval shunts or ammonia infusions suggests that this toxin may alter flow and metabolism and that this, in turn, causes the clinical expression of encephalopathy.  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