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   1699篇
  免费   293篇
  国内免费   39篇
耳鼻咽喉   13篇
儿科学   102篇
妇产科学   19篇
基础医学   103篇
口腔科学   27篇
临床医学   282篇
内科学   577篇
皮肤病学   60篇
神经病学   172篇
特种医学   279篇
外科学   184篇
综合类   31篇
预防医学   59篇
眼科学   16篇
药学   53篇
中国医学   1篇
肿瘤学   53篇
  2023年   52篇
  2022年   12篇
  2021年   27篇
  2020年   90篇
  2019年   12篇
  2018年   88篇
  2017年   69篇
  2016年   69篇
  2015年   60篇
  2014年   95篇
  2013年   110篇
  2012年   44篇
  2011年   35篇
  2010年   76篇
  2009年   108篇
  2008年   43篇
  2007年   48篇
  2006年   45篇
  2005年   29篇
  2004年   14篇
  2003年   11篇
  2002年   14篇
  2001年   29篇
  2000年   12篇
  1999年   24篇
  1998年   80篇
  1997年   95篇
  1996年   78篇
  1995年   69篇
  1994年   49篇
  1993年   52篇
  1992年   26篇
  1991年   15篇
  1990年   27篇
  1989年   53篇
  1988年   42篇
  1987年   26篇
  1986年   20篇
  1985年   20篇
  1984年   17篇
  1983年   9篇
  1982年   14篇
  1981年   14篇
  1980年   14篇
  1979年   8篇
  1978年   8篇
  1977年   9篇
  1976年   10篇
  1975年   7篇
  1971年   8篇
排序方式: 共有2031条查询结果,搜索用时 31 毫秒
991.
992.
HUGO PARTSCH  MD  PHD    MICHAEL CLARK  PHD    GIOVANNI MOSTI  MD    ERIK STEINLECHNER  DSC    JAN SCHUREN  RN  BN  MSC    MARTIN ABEL  PHD    JEAN-PATRICK BENIGNI  MD    PHILIP COLERIDGE-SMITH  DM  FRCS    RE CORNU-THÉNARD  MD    MIEKE FLOUR  MD    JERRY HUTCHINSON  PHD  BSC    JOHN GAMBLE  PHD    KARIN ISSBERNER  PHD    MICHAEL JUENGER  MD  PHD    CHRISTINE MOFFATT  CBE  PHD  MA  RGN  DN    H. A. M. NEUMANN  MD  PHD    EBERHARD RABE  MD  PHD    JEAN F. UHL  MD    STEVEN ZIMMET  MD 《Dermatologic surgery》2008,34(5):600-609
  相似文献   
993.
BACKGROUND: Infectious and non-infectious hand and forearm dermatoses are frequent in daily veterinary medicine. In this specific occupation there is a serious impact of skin disease on the lives and careers of veterinarians. OBJECTIVE: In this study we clarify the different occupational dermatoses on hands and forearms among veterinarians, using data collected in different dermatological patch-test expert centres in Belgium and the Netherlands. METHODS: Instead of questioning veterinarians themselves, which has been done in different studies in the past, we contacted dermatologists in Belgium and the Netherlands, questioning them about their experiences with dermatoses among veterinarians. RESULTS: Seven dermatologists described a total of 58 veterinarians. Infectious dermatoses were described in 12 cases (20.7%). The non-infectious dermatoses (46 cases, 79.3%) can be classified as contact urticaria and as irritant or allergic contact dermatitis. CONCLUSION: While irritant contact dermatitis accounts for the vast majority of hand and forearm dermatoses among veterinarians, contact urticaria and allergic contact dermatitis also significantly contribute to the occupational morbidity. Repeated hand washing, occlusion under rubber gloves, contact with animal protein fluids during obstetric procedures and contact with antiseptic agents, systemic and topical corticosteroids and antibiotics are the most likely causes of hand and forearm dermatoses among veterinarians.  相似文献   
994.
995.
Background Ebstein’s anomaly of the tricuspid valve is a complex malformation. Historically, because valve replacement yielded poor results, surgical treatment has focused on valvuloplasties with or without associated procedures. An individualised combination of surgical procedures was practised over three years and forms the subject of this presentation. Method Between November 1995 and September 1999, 7 patients with Ebstein’s anomaly underwent surgical repair (age 3.5 to 40 years). Cyanosis with severe tricuspid regurgitation was present in all. Surgical repair, individualised according to the morphology of the tricuspid valve and right ventricle to provide maximum possible symptom free survival, included, (1) Tricuspid valve: Replacement (n=1); Repair (Carpentier type n=1, Unicuspid repair n=5), (2) Atrial septal defect: left open (n=1), closed partially (n=1), closed compeletely (n=5), and (3) Bidirectional Cavopulmonary Shunt (BCPS)-4 Results There was no hospital death. Intraoperative transoesophageal echocardiography showed only mild tricuspid regurgitation in all, following repair. There were no late deaths at a mean follow up of 29 months. All but one patient were in functional Class 1 New York Heart Association(NYHA). Complications included a thrombus in the right ventricular cavity six months postoperatively in one patient. Conclusion Individualisation of surgical management in Ebstein’s anomaly provides optimal results.  相似文献   
996.
997.
Erythromycin, a motilin receptor agonist has been shown to have prokinetic effects on the upper gastrointestinal tract and gallbladder. Colonic effects of the drug are controversial, and it is debated whether human colon contains motilin receptors. In this study we evaluated the effects of erythromycin on colonic transit and stool frequency in 11 patients with idiopathic constipation over a 1-month period in an open study. The dose used was 1 g/day for two weeks followed by 500 mg/day for another two weeks. The mean (se) total and segmental colonic transit was measured before and seven days after therapy in seven of these patients. A daily record of stool frequency was maintained in all 11 patients. Erythromycin shortened the total colonic transit from 86.2 (14.6) to 44.8 (8.99) hr (P<0.01); however, segmental transit studies revealed a significant effect (P<0.01) only in the right colon and rectosigmoid region. No significant side effects were observed with short-term therapy. These preliminary results suggest that erythromycin is of therapeutic value in patients with idiopathic constipation.  相似文献   
998.
Radiation-induced proctosigmoiditis   总被引:9,自引:0,他引:9  
In a prospective study, 37 consecutive patients with radiation-induced proctosigmoiditis were randomized to receive a four-week course of either 3.0 g oral sulfasalazine plus 20 mg twice daily rectal prednisolone enemas (group I, N = 18) or 2.0 g twice daily rectal sucralfate enemas plus oral placebo (group II, N = 19). The two groups were comparable with respect to demographic features, duration of symptoms, and clinical and endoscopic staging of the disease. Fifteen patients in group I and 17 in group II completed the trial. At four weeks, both groups showed significant clinical improvement (P less than 0.01 for group I and P less than 0.001 for group II) and endoscopic healing (P less than 0.01 for group I and P less than 0.001 for group II). When the two groups were compared, sucralfate enemas showed a significantly better response as assessed clinically (P less than 0.05), although endoscopically the response was not statistically different (P greater than 0.05). We conclude that both treatment regimens are effective in the management of radiation proctitis. Sucralfate enemas give a better clinical response, are tolerated better, and because of the lower cost should be the preferred mode of short-term treatment.  相似文献   
999.
A hybridoma-derived monoclonal antibody, produced by immunization with the Burkitt's tumor-derived B-lymphoblastoid cell line, B35M, was previously shown to detect a 68,000 dalton surface membrane protein, BL2, on the surface of peripheral blood B cells, which is absent from thymocytes, T cells, and granulocytes. In this study, we investigated the expression and distribution of BL2 on benign and malignant human lymphoid cells. Indirect immunofluorescent assay with this monoclonal antibody demonstrated that BL2 is expressed by cells within the fetal liver and by a variable proportion of lymph node, tonsil, and spleen B cells, but not by T cells. The neoplastic cells isolated from 18 T-cell malignancies were BL2- . BL2 was was heterogeneously expressed by a variable proportion of the malignant cells in 29/32 cases of B-chronic lymphocytic leukemia and 33/38 cases of B-cell lymphomas, but appeared to be lost in the terminal stages of B-cell differentiation, as myeloma plasma cells were BL2- . BL2 expression was not limited to B cells of a particular surface immunoglobulin isotype. Immunofluorescent staining for BL2 in cryostat tissue sections demonstrated that the majority, but not all, germinal center and interfollicular Ia+ (non-T) cells are BL2+. These findings suggest that BL2 is a B-cell lineage-specific differentiation marker that may be useful in the study of B-cell ontogeny and in defining subgroups of the B-cell malignancies.  相似文献   
1000.
Nawroth  PP; Stern  DM; Kaplan  KL; Nossel  HL 《Blood》1984,64(4):801-806
This study reports that endotoxin (Escherichia coli serotype 026:B6) and 12-O-tetradecanoyl-phorbol-13-acetate stimulate cultured bovine aortic endothelial cells to generate prostacyclin. The prostacyclin concentration of the culture medium was measured indirectly by radioimmunoassay for 6-keto-PGF1 alpha. The amount of prostacyclin generated depended on the concentration of endotoxin or phorbol diester. Prostacyclin generation was not immediate, but occurred slowly after a six-hour lag period. The perturbed cells contracted and showed marked shape changes that correlated temporally with the start of enhanced prostacyclin production. Cytochalasins B and D, vinblastine, and colchicine inhibited prostacyclin production, indicating involvement of the cytoskeleton in the cellular response to endotoxin and phorbol diester. The increase in prostacyclin production was prevented by trifluoperazine, an inhibitor of the Ca++-calmodulin system, which is known to be involved in cytoskeletal function. Generation of prostacyclin was inhibited by cycloheximide and actinomycin D, indicating dependence on protein and ribonucleic acid synthesis. It is postulated that exposure to endotoxin or phorbol diester leads, via a series of reactions that involve RNA and protein synthesis and require intact cytoskeletal function, to the generation of toxic active intermediate(s) that stimulate the enzymes necessary for prostacyclin production.  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