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   2666905篇
  免费   236424篇
  国内免费   22328篇
耳鼻咽喉   35745篇
儿科学   80564篇
妇产科学   64441篇
基础医学   443788篇
口腔科学   69172篇
临床医学   242127篇
内科学   444890篇
皮肤病学   76549篇
神经病学   231253篇
特种医学   103970篇
外国民族医学   96篇
外科学   413928篇
综合类   107585篇
现状与发展   52篇
一般理论   2013篇
预防医学   226510篇
眼科学   60238篇
药学   184463篇
  144篇
中国医学   16104篇
肿瘤学   122025篇
  2022年   27905篇
  2021年   60640篇
  2020年   39398篇
  2019年   61443篇
  2018年   73004篇
  2017年   56254篇
  2016年   61093篇
  2015年   77825篇
  2014年   113107篇
  2013年   177565篇
  2012年   77166篇
  2011年   73451篇
  2010年   116234篇
  2009年   121328篇
  2008年   57715篇
  2007年   56956篇
  2006年   68403篇
  2005年   63554篇
  2004年   64470篇
  2003年   55951篇
  2002年   45496篇
  2001年   59120篇
  2000年   49784篇
  1999年   59158篇
  1998年   61749篇
  1997年   60812篇
  1996年   57670篇
  1995年   53249篇
  1994年   47336篇
  1993年   44182篇
  1992年   36903篇
  1991年   34187篇
  1990年   31439篇
  1989年   31868篇
  1988年   29751篇
  1987年   28842篇
  1986年   27420篇
  1985年   28690篇
  1984年   31405篇
  1983年   30221篇
  1982年   35861篇
  1981年   34301篇
  1980年   32385篇
  1979年   23306篇
  1978年   24521篇
  1977年   23608篇
  1976年   21363篇
  1975年   18861篇
  1974年   17397篇
  1973年   16654篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Advanced malignant melanomas of the uvea unsuited for an eye salvaging approach require enucleation of the tumor containing eye. A series of 68 patients is reported who underwent enucleation combined with insertion of a spherical dura-encased implant after 30 Gray pre-irridiation therapy of the orbit. Postoperative results with special attention to cosmetic outcome and motility of the prosthesis suggest that the insertion of an orbital implant should be preferred to the enucleation with no implant.  相似文献   
992.
A long-term clinical and therapeutic study was performed in 47 patients with mesangial IgA glomerulonephritis. The male to female ratio was 2.9∶1. An episode of gross haematuria or the incidental discovery of asymptomatic microscopic haematuria with associated mild proteinuria heralded the apparent onset of renal disease. At the onset of observation 18 patients (38.2%) had high blood pressure. Other 17 patients developed hypertension during observation. Anaemia was uncommon. No essential abnormalities in serum protein and lipid patterns were found. Twenty-nine patients (61.6%) had higher levels of serum immunoglobulins—most frequently of IgA (42.5%). Twenty-two patients had low serum C3 levels (46.8%). The percentage of patients with renal failure increased from 21.2 to 36.1 during observation. Male sex, hypertension, proteinuria higher than 2 g/24 h, elevated ESR, high serum IgA levels, longer duration of the disease and older age of patients suggest an unfavourable outcome. Long-term treatment with a combination of azathioprine/acenocumarol, or indomethacin, or levamisole has no effect on the clinical manifestation and evolution.  相似文献   
993.
Zusammenfassung Bei einem 55jährigen Mann wurde 7 Monate nach orthotoper Lebertransplantation eine Lungentuberkulose diagnostiziert. Die tuberculostatische Therapie erfolgte mit Isoniazid (3 x 0,2 g/Wo) und Ethambutol (1,6 g/d) über 11 Monate. Nach 3 Monaten waren keine Mycobakte rien mehr nachweisbar, und der Patient ist im 3. Jahr nach Transplantation ohne Zeichen einer aktiven Tuberkulose in gutem Gesundheitszustand bei guter Transplantatfunktion. Die Tuberculostatica-Dosierung sollte je nach Metabolisierungsleistung des Transplantats reduziert werden. Bei Beachtung dieses Kardinalpunktes könnte eine Tuberkulose nach Lebertransplantation erfolgreich behandelt werden.  相似文献   
994.
995.
996.
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182  相似文献   
997.
Platelet antibodies in systemic lupus erythematosus   总被引:2,自引:0,他引:2  
In systemic lupus erythematosus (SLE), the precise cause of the thrombocytopenia is unknown. Since platelet associated IgG is increased in many patients, it has been suggested that the destruction of platelets might be dependent on specific antibodies. In nine patients with SLE, platelet associated immunoglobulins were found together with free serum antibody which bound to platelets from all normal subjects. Using an immunoblotting technique with membrane proteins from normal platelets incubated with patient sera, target antigens were localized on a band of mol wt 108,000 in two cases (B. and N.) and on a band of mol wt 66,000 in a third (M.). When the same technique was applied to autologous platelets of patient N., autoantibody binding to the protein of mol wt 108,000 was demonstrated. The antigenic determinants were not removed from the platelets by enzyme treatment or by disulphide bond reduction, and were localized in the cytoplasmic fraction of the platelets.  相似文献   
998.
Repeated testing attenuates conditioned place preference with cocaine   总被引:2,自引:2,他引:0  
Cocaine-treated rats acquired a preference for cocaine-associated contextual stimuli (CS) relative to saline-injected control rats. However, when animals were given repeated tests for conditioned place preference intermittent between conditioning trials, they displayed an attenuation in strength of conditioning. This attenuation was not due to pharmacologic tolerance (Experiment 1), but rather reflected a disruption in learning due to exposure to the CS alone (Experiment 2). Like other examples of classical conditioning, the strength of the conditioned response (CR) as assessed by the conditioned place preference model may be influenced by partial reinforcement.  相似文献   
999.
Wheat germ agglutinin (WGA) was found to stimulate DNA synthesis in human peripheral blood mononuclear cells at relatively low concentrations and to inhibit DNA synthesis at higher concentrations. Both actions were inhibited by oligomers of N-acetyl-D-glucosamine. Significant mitogenic activity was dependent on the use of human (as opposed to fetal calf) serum to supplement the culture medium. Purified T cells responded to WGA very weakly and the incorporation of thymidine into non-T cells in response to WGA was less than the lectin-free control. The full ability of T cells to respond to WGA was restored by the addition of monocytes, but not by any other blood cells. Interleukin 2 partially restored the ability of T cells to respond to WGA; interleukin 1 was less effective. WGA displayed a strong synergistic action with the tumour promoter, 12-O-tetradecanoyl-13-acetate (TPA), in stimulating DNA synthesis in separated T (but not non-T) cell fractions, and in unfractioned mononuclear cells. These results reconcile most of the conflicting reports in the literature concerning the interaction of WGA with human lymphocytes.  相似文献   
1000.
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