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   15508篇
  免费   1509篇
  国内免费   69篇
耳鼻咽喉   236篇
儿科学   547篇
妇产科学   365篇
基础医学   1921篇
口腔科学   441篇
临床医学   1117篇
内科学   3453篇
皮肤病学   599篇
神经病学   906篇
特种医学   584篇
外国民族医学   6篇
外科学   2767篇
综合类   149篇
一般理论   2篇
预防医学   1132篇
眼科学   418篇
药学   1234篇
中国医学   91篇
肿瘤学   1118篇
  2023年   106篇
  2022年   352篇
  2021年   621篇
  2020年   413篇
  2019年   672篇
  2018年   846篇
  2017年   582篇
  2016年   620篇
  2015年   548篇
  2014年   770篇
  2013年   1033篇
  2012年   1199篇
  2011年   1305篇
  2010年   840篇
  2009年   764篇
  2008年   841篇
  2007年   817篇
  2006年   767篇
  2005年   632篇
  2004年   591篇
  2003年   397篇
  2002年   389篇
  2001年   293篇
  2000年   316篇
  1999年   227篇
  1998年   92篇
  1997年   70篇
  1996年   66篇
  1995年   44篇
  1994年   40篇
  1993年   36篇
  1992年   34篇
  1991年   35篇
  1990年   25篇
  1989年   27篇
  1988年   27篇
  1987年   23篇
  1985年   27篇
  1984年   81篇
  1983年   67篇
  1982年   42篇
  1981年   26篇
  1980年   41篇
  1979年   44篇
  1978年   43篇
  1977年   33篇
  1976年   35篇
  1975年   38篇
  1974年   20篇
  1973年   17篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
41.
42.
Y M El?in  U Akbulut 《Biomaterials》1992,13(3):156-161
Glucose oxidase was immobilized into photographic gelatin hardened by chromium(III) sulphate. The enzyme-gelatin mixture was coated on polyester film strips which allowed easy and simple handling during assays. The effect of gelatin and cross-linker concentrations on water content and enzymatic activity was studied. The effect of pH during immobilization and that of incubation temperature on maximum activity were examined. Enzyme leakage tests were carried out during reuse number studies. Consecutive use of strips followed by washing and resting between uses were found to affect the reuse number. A maximum immobilization of 68% was reached under optimal conditions. Mechanical stability and leakage were found to be functions of gelatin and cross-linker concentrations. Photographic gelatin was found to have many capabilities with extraordinary characteristics as a carrier on immobilization.  相似文献   
43.
Venous thrombosis is rare in children. It can be either acquired or of constitutional origin. Thrombosis during non-Hodgkin lymphoma remains exceptional and is usually locally associated to the tumoral process, raising the issue of its tumoral or cruoric nature. The treatment is based on anticoagulation concomitantly to chemotherapy. We report on a 4-year-old boy admitted for mediastinal non-Hodgkin lymphoma, who developed a thrombosis of the superior vena cava associated to protein S-deficiency. The mechanism of thrombosis may have been multifactorial: associated protein S-deficiency, vascular compression, tumoral process and chemotherapy.  相似文献   
44.
Recombinant activated factor VII has been Food and Drug Administration approved to treat hemorrhages in hemophiliac patients with inhibitors and in acquired hemophilia patients. Recombinant activated factor VII use has also been considered for the management of uncontrolled bleeding in a number of congenital and acquired hemostatic abnormalities. The myeloproliferative disorders are a group of clonal hematologic diseases where, frequently, abnormal platelet function is considered a hallmark. This is the first case report addressing the clinical benefit of off-label use of recombinant activated factor VII in an attempt to control intractable bleeding in a patient with a myeloproliferative disorder after splenectomy.  相似文献   
45.
46.
47.
BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited human kidney disease and is caused by germline mutations in PKD1 (85%) or PKD2 (15%). It has been estimated that around 1% of tubular cells give rise to cysts, and cell hyperproliferation has been noted to be a cardinal feature of cystic epithelium. Nevertheless, it is uncertain whether the increase in proliferative index observed is an early or late feature of the cystic ADPKD kidney. METHODS: Two Pkd2 mouse mutants (WS25 and WS183) have been recently generated as orthologous models of PKD2. To determine the effect of Pkd2 dosage on cell proliferation, cyst formation and renal fibrosis, we studied renal tissue from Pkd2(WS25/WS25) and Pkd2(+/-) mice by histological analysis. We also examined the proliferative index in archival nephrectomy tissue obtained from patients with ADPKD and normal controls. RESULTS: The proliferative index of non-cystic tubules in Pkd2 mutant mice as assessed by proliferating cell nuclear antigen and Ki67-positive nuclei was between 1-2%, values 5-10 times higher than control tissue. Similarly, the proliferative index of non-cystic tubules in human ADPKD kidneys was 40 times higher than corresponding controls. In Pkd2 mutant mice, significant correlations were found between the fibrosis score and the mean cyst area as well as with the proliferative index. Of significance, proliferating tubular cells were uniformly positive for polycystin-2 expression in Pkd2(+/-) kidney. CONCLUSION: These results suggest that an increase in cell proliferation is an early event preceding cyst formation and can result from haploinsufficiency at Pkd2. The possible pathogenic link between tubular cell proliferation, interstitial fibrosis and cyst formation is discussed.  相似文献   
48.
Objective. – To describe the clinical and radiological features of foot involvement in patients with psoriatic arthritis.Methods. – We retrospectively reviewed the medical records of patients admitted between 1972 and 1999 for psoriatic arthritis with involvement of the foot. We included all patients who had peripheral and/or axial, asymmetric, chronic inflammatory joint disease meeting or not Avila's radiological criteria for psoriatic arthritis, with or without other imaging findings suggestive of psoriatic arthritis and with or without psoriasis.Results. – Twenty-six patients were included. Inflammatory heel pain was reported by 14 patients, whereas forefoot involvement was found in only seven patients. Sausage toe was present in two patients. None of the patients had Bauer's toe (combining arthritis and psoriatic skin and/or nail changes) or psoriatic onychopachydermoperiostitis of the great toe. Radiological abnormalities were found in 20 patients. Half the patients had calcaneal changes. Osteoperiostitis of the great toe was noted in two patients and mushrooming in five.Discussion. – The features of psoriatic arthritis in Morocco seem similar to those in other countries. Hindfoot involvement was present in 53% of patients. Involvement of the forefoot was rarely recorded in the charts, suggesting missed cases because of insufficient attention to the forefoot during the physical examination and availability of anteroposterior radiographs only. Oblique views (Hirtz and Chaumet) should be obtained because they give a clearer image of the distal part of the toes, which is often difficult to analyze on anteroposterior films.  相似文献   
49.
The development of therapeutic options for rectal cancer strives to reach the ultimate goals of improved local control and overall survival. However, preserving continence, as well as genitourinary and sexual function, remains elusive in some patients. Loss of bowel control may be the most unsettling factor in terms of quality of life. Patients must be accurately informed about the surgery’s possible adverse effects, and surgeons must offer the best options (e.g. colostomy bag or sphincteroplasty) in order to minimize these complaints.  相似文献   
50.
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