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   741篇
  免费   97篇
  国内免费   13篇
耳鼻咽喉   1篇
儿科学   22篇
妇产科学   6篇
基础医学   127篇
口腔科学   14篇
临床医学   88篇
内科学   142篇
皮肤病学   7篇
神经病学   10篇
特种医学   191篇
外科学   73篇
综合类   52篇
预防医学   30篇
眼科学   4篇
药学   14篇
  1篇
肿瘤学   69篇
  2021年   10篇
  2019年   6篇
  2018年   14篇
  2017年   12篇
  2016年   12篇
  2015年   15篇
  2014年   29篇
  2013年   19篇
  2012年   31篇
  2011年   37篇
  2010年   16篇
  2009年   14篇
  2008年   10篇
  2007年   32篇
  2006年   24篇
  2005年   17篇
  2004年   20篇
  2003年   18篇
  2002年   8篇
  2001年   10篇
  2000年   6篇
  1999年   8篇
  1998年   28篇
  1997年   26篇
  1996年   18篇
  1995年   25篇
  1994年   22篇
  1993年   35篇
  1992年   9篇
  1991年   8篇
  1990年   12篇
  1989年   21篇
  1988年   25篇
  1987年   37篇
  1986年   23篇
  1985年   22篇
  1984年   9篇
  1983年   13篇
  1982年   8篇
  1981年   13篇
  1980年   12篇
  1978年   10篇
  1977年   10篇
  1976年   6篇
  1975年   12篇
  1974年   10篇
  1973年   14篇
  1972年   9篇
  1971年   8篇
  1970年   9篇
排序方式: 共有851条查询结果,搜索用时 937 毫秒
51.
52.
Cyclooctylamine in the prevention of experimental human influenza   总被引:1,自引:0,他引:1  
Y Togo  A R Schwartz  S Tominaga  R B Hornick 《JAMA》1972,220(6):837-841
  相似文献   
53.
Sources of contamination in open heart surgery   总被引:6,自引:0,他引:6  
R M Kluge  F M Calia  J S McLaughlin  R B Hornick 《JAMA》1974,230(10):1415-1418
  相似文献   
54.

Background

In view of increase in incidence of exptrapulmonary tuberculosis after the epidemic of human immunodeficiency virus infection, the clinical profile of extrapulmonary tuberculosis in patients with HIV infection was studied.

Method

The study population comprised patients of HIV infection with extrapulmonary tuberculosis. Work up included history, clinical examination, sputum for acid fast bacilli, chext X-ray, ultrasonography (USG) abdomen, fine needle aspiration cytology(FNAC), transbronchial needle aspiration (TBNA) and computed tomography of chest.

Results

There were 50 cases, all males with mean age of 35 years. 24(48%) were without pulmonary tuberculosis and 26(52%) had pulmonary tuberculosis. 41(82%) had disseminated disease and 9(18%) involve one site. Fever and weight loss were the most frequent symptoms (79% and 58% respectively) in cases without pulmonary tuberculosis. The most frequent extrapulmonary site was lymph node in 46(92%), followed by spleen in 13(26%), pleura 9(18%), miliary 7(14%) and hepatic 1(2%). The diagnosis was confirmed by invasive methods in 30 out of 50(60%) cases [FNAC in 23(88%), TBNA in 2(25%) and pleural biopsy in 5(55%)].

Conclusion

In HIV infected patients, the most common extrapulmonary site is lymph mode followed by spleen.Key Words: Extrapulmonary TB, HIV Infection  相似文献   
55.
56.
Histiocytic sarcoma is a rare malignant neoplasm that occurs in lymph nodes, skin, and the gastrointestinal tract. Many previously published cases were likely misdiagnosed examples of non-Hodgkin lymphoma. Only small numbers of bona fide examples exist in the world literature; cases arising primarily at extranodal sites are not well described and often seem to go unrecognized. To characterize these tumors further, 14 extranodal histiocytic sarcomas were analyzed. Hematoxylin and eosin sections were reexamined, immunohistochemistry was performed, and clinical details were obtained from referring hospitals. Eight patients were female and 6 male (median age, 55 years; range, 15-89 years). All patients presented with a solitary mass, ranging in size from 1.8 to 12 cm (median 6.8 cm). Seven tumors arose in soft tissue (6 lower limb; 1 upper limb), 5 in the gastrointestinal tract (1 involving both stomach and colon, 1 ileum, 2 rectum, 1 anus), 1 in the nasal cavity, and 1 in the lung. Three gastrointestinal tract tumors also involved regional lymph nodes, and 1 involved the liver. Most cases had infiltrative margins. The tumors were generally composed of sheets of large epithelioid cells with abundant eosinophilic cytoplasm, oval to irregular nuclei, vesicular chromatin, and large nucleoli. Binucleated cells were common, and 6 cases contained tumor giant cells. Mitoses ranged from 1 to 64 per 10 HPF (median 11 per 10 HPF). Necrosis was present in 8 cases. Nearly all tumors showed a striking inflammatory infiltrate, most often of neutrophils or lymphocytes. All cases were reactive for LCA, CD45RO, and CD68 (KP1 and PG-M1); 13 of 14 (93%) expressed CD4, 12 of 14 (86%) lysozyme, 8 of 10 (80%) CD31, 7 of 14 (50%) S-100 protein, and 5 of 14 (36%) focal CD1a. Two tumors showed weak, focal cytoplasmic positivity for CD30, and 1 for epithelial membrane antigen. The tumors were negative for ALK-1, CD21, CD35, CD3, CD20, CD34, myeloperoxidase, HMB-45, and keratins. Gastrointestinal tract cases were negative for c-kit and desmin. Six patients were treated with postoperative radiation and 7 with chemotherapy (CHOP or ProMACE-MOPP). Follow-up was available for 10 patients (median, 24 months; range, 4 months to 11 years). Two tumors recurred locally, and 5 patients developed distant spread: 3 to lymph nodes, 1 to lung, and 1 to bone. At the last follow-up, 2 patients have died of disseminated disease, 4 and 5 months following initial diagnosis. The patients who died thus far had the largest primary tumors. Histiocytic sarcoma may arise primarily in soft tissue and shows reproducible histologic features, including abundant eosinophilic cytoplasm and a prominent inflammatory infiltrate. Metastatic carcinoma, metastatic melanoma, and large cell non-Hodgkin lymphomas should be excluded by immunohistochemistry. Histiocytic sarcoma has the potential for an aggressive clinical course, most often with lymph node involvement. However, a subset of cases presenting with clinically localized disease have a favorable long-term outcome. Tumor size may be a prognostic factor.  相似文献   
57.
58.
We present two patients with renovascular hypertension in association with neurofibromatosis. In both cases the diagnosis was established by angiography. The first patient suffered occlusion of the right renal artery combined with intrarenal arterial lesions. Treatment was by autotransplantation. The second patient suffered bilateral intrarenal arterial lesions alone and was treated medically. In both patients, control of the hypertension was established. We discuss the aetiology of renovascular hypertension in neurofibromatosis and consider its treatment.  相似文献   
59.
Psoriasis is associated with significant physical and psychological burden affecting all facets of a patient’s life – relationships, social activities, work and emotional wellbeing. The cumulative effect of this disability may be self‐perpetuating social disconnection and failure to achieve a ‘full life potential’ in some patients. Health‐related quality of life studies have quantified the burden of psoriasis providing predominantly cross‐sectional data and point‐in‐time images of patients’ lives rather than assessing the possible cumulative disability over a patient’s lifetime. However, social and economic outcomes indicate there are likely negative impacts that accumulate over time. To capture the cumulative effect of psoriasis and its associated co‐morbidities and stigma over a patient’s life course, we propose the concept of ‘Cumulative Life Course Impairment’ (CLCI). CLCI results from an interaction between (A) the burden of stigmatization, and physical and psychological co‐morbidities and (B) coping strategies and external factors. Several key aspects of the CLCI concept are supported by data similar to that used in health‐related quality of life assessments. Future research should focus on (i) establishing key components of CLCI and determining the mechanisms of impairment through longitudinal or retrospective case–control studies, and (ii) assessing factors that put patients at increased risk of developing CLCI. In the future, this concept may lead to a better understanding of the overall impact of psoriasis, help identify more vulnerable patients, and facilitate more appropriate treatment decisions or earlier referrals. To our knowledge, this is a first attempt to apply and develop concepts from ‘Life Course Epidemiology’ to psoriasis research.  相似文献   
60.
A randomized, double-blind, multicenter study was conducted to investigate the boosting effect of Vaqta or Havrix in 537 healthy adults 18-53 years of age who had received a single dose of Havrix either 24 or 52 weeks earlier. Subjects were randomized in a 2 : 1 ratio to receive either Vaqta or Havrix for their second dose of vaccine and followed for clinical reactions for 14 days after dose 2 was administered. Serum samples were collected immediately before dose 2 was administered and again 4 weeks later and evaluated for hepatitis A antibody (modified hepatitis A virus antibody assay). The booster response rate after administration of the second dose of either vaccine was similar (86.1% for Vaqta vs. 80.1% for Havrix). The geometric mean titers were also similar: 3274 mIU/mL (95% confidence interval [CI], 2776-3858) for Vaqta versus 2423 mIU/mL (95% CI, 1911-3074) for Havrix. The proportion of subjects who reported > or =1 injection-site adverse experiences was lower in the patients receiving Vaqta than in those receiving Havrix (36.6% vs. 59.7%; P<.001). The results of this study indicate that a regimen of Havrix followed by Vaqta is generally well tolerated and highly immunogenic.  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