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   957篇
  免费   40篇
  国内免费   3篇
耳鼻咽喉   1篇
儿科学   35篇
妇产科学   3篇
基础医学   101篇
口腔科学   29篇
临床医学   68篇
内科学   160篇
皮肤病学   13篇
神经病学   34篇
特种医学   88篇
外科学   80篇
综合类   123篇
预防医学   86篇
眼科学   10篇
药学   34篇
肿瘤学   135篇
  2021年   33篇
  2020年   6篇
  2019年   10篇
  2018年   11篇
  2017年   5篇
  2016年   6篇
  2015年   15篇
  2014年   13篇
  2013年   17篇
  2012年   25篇
  2011年   23篇
  2010年   42篇
  2009年   33篇
  2008年   38篇
  2007年   37篇
  2006年   48篇
  2005年   36篇
  2004年   31篇
  2003年   25篇
  2002年   27篇
  2001年   24篇
  2000年   24篇
  1999年   29篇
  1998年   39篇
  1997年   29篇
  1996年   37篇
  1995年   22篇
  1994年   35篇
  1993年   12篇
  1992年   10篇
  1991年   5篇
  1990年   21篇
  1989年   21篇
  1988年   27篇
  1987年   29篇
  1986年   20篇
  1985年   18篇
  1984年   16篇
  1983年   12篇
  1982年   7篇
  1981年   11篇
  1980年   12篇
  1979年   7篇
  1978年   7篇
  1977年   8篇
  1976年   7篇
  1975年   5篇
  1973年   4篇
  1972年   5篇
  1969年   4篇
排序方式: 共有1000条查询结果,搜索用时 15 毫秒
51.
PURPOSE: Vulvovaginal candidiasis (VVC) is believed common after systemic antibiotic therapy, yet few studies demonstrate this association. In this pilot study, we evaluate the effect of short-course oral antibiotic use on VVC. METHODS: Nonpregnant women aged 18 to 64 years who required >or=3 days oral antibiotics for nongynecological diseases were recruited from a family medicine office. Age-matched (+/-5 years) women seen in the same clinic for noninfectious problems were recruited as controls. The main outcomes are incidence of symptomatic VVC and prevalence of positive vaginal Candida culture 4 to 6 weeks after antibiotics. RESULTS: Eighty (44 in antibiotic group) women were recruited; 14 of 79 (95% CI, 0.11-0.28) had asymptomatic vaginal Candida cultures positive at baseline. During follow-up, 10 of 27 (95% CI, 0.22-0.56) women in antibiotic group were Candida culture positive. In contrast, 3 of 27 (95% CI, 0.04-0.28) women in the control group were Candida culture positive (relative risk, 3.33; P = .03). Meanwhile, 6 of 27 (95% CI, 0.11-0.41) women in antibiotic group developed symptomatic VVC whereas none (95% CI, 0-0.12) of the women in the control group developed vaginal symptoms (relative risk, infinity; P = .02). Baseline Candida culture did not predict subsequent symptomatic VVC after antibiotics. CONCLUSION: In this pilot study, the use of short courses of oral antibiotics seems to increase prevalence of asymptomatic vaginal Candida colonization and incidence of symptomatic VVC. Larger cohort studies are needed to confirm these findings.  相似文献   
52.
绝经后女性类风湿关节炎患者骨密度变化影响因素分析   总被引:2,自引:0,他引:2  
目的探讨绝经后女性类风湿关节炎(RA)患者发生骨质疏松(OP)的原因。方法收集63例绝经后女性RA患者一般临床资料、疾病活动相关指标、手足X线资料,并同时测量患者7个部位的骨密度。结果23例患者(36.5%)有至少一处检测部位表现为低骨量。前臂和桡尺骨远端的低骨密度发生率(23.8%)与OP总发生率(28.6%)无显著性差异(P>0.05)。OP的发生与疾病活动指标及糖皮质激素的使用均无相关性。多元回归分析显示绝经的年限和关节腔狭窄为低骨量发生的独立危险因素(P<0.05);而雌激素替代疗法(HRT)为低骨量发生的唯一保护因素(P<0.05),小剂量糖皮质激素对本组患者的骨密度无影响。结论OP是绝经后女性RA患者的常见并发症,绝经年限长和关节破坏严重是低骨量发生的独立危险因素,HRT是防治低骨量的保护因素。  相似文献   
53.
Very few data exist that describe the risk of injury in African American health care workers, who are highly represented in health care occupations. The present study examined the risk for work-related injury in African American hospital workers. Hospital Occupational Health Service medical records and a hospital human resource database were used to compare risk of injury between African American and white workers after adjusting for gender, age, physical demand of the job, and total hours worked. Risk of work-related injury was 2.3 times higher in African Americans. This difference was not explained by the other independent variables. Differences in injury reporting, intra-job workload, psychosocial factors, and organizational factors are all potential explanations for racial disparity in occupational injury. More research is needed to clarify these findings.  相似文献   
54.
55.
An increase in the rate of breast-feeding is beneficial for the developing countries both with regard to economy and health (1). The nutritional and immunological superiority of breastfeeding compared to artificial feeding is universally recognized. Breast-feeding has advantages not only for the infant but also for the mother and the family unit. It has also been recognized as the most effective method of birth-spacing in developing countries (2, 3) and it has advantages for the family because of its convenience and low cost (4).  相似文献   
56.
57.
5-Fluorouracil in combination with leucovorin has been shown to be active in therapeutic trials of metastatic colorectal carcinoma. In this study, we administered these drugs to 72 patients with metastatic colorectal carcinoma. Thirty-six of them without previous exposure to 5-fluorouracil were treated with weekly bolus injections of 5-fluorouracil (425 mg/m2) and leucovorin (25 mg/m2) supplemented with oral levamisole. Another 36 patients with or without prior 5-fluorouracil treatment received 5-fluorouracil 3,000 mg/m2 and leucovorin 300 mg/m2 in a 48-hour continuous infusion every two weeks. Clinical efficacy and toxicity were assessed by WHO criteria. Variables were tested for relations to response and survival by univariate and multivariate analysis. The response rate was 19.4% in weekly bolus arm and 13.9% in biweekly high-dose infusion arm (P = 0.527). Median survivals in the two arms were 18.4 months (weekly) and 21 months (biweekly) respectively (P = 0.708). Gastrointestinal side effects including nausea, vomiting, diarrhea and mucositia were the major toxicities of these regimens. By multivariate analysis, the only factor to influence response rate was the site of metastases (P = 0.009). The only factor to affect survival was performance status of the patient (P = 0.0001). We concluded that the two 5-fluorouracil based regimens are well-tolerated and shown to have a response rate comparable with previous reports of similar regimens in patients with metastatic colorectal cancer. Only liver metastases seemed to have a better response to therapy. Performance status is the most important prognostic factor in patients with metastatic colorectal cancer.   相似文献   
58.
A 28-year-old woman was admitted to our Hospital with a chief complaint of progressive gingival swelling and loosening of teeth over about a year. According to past history, she had received total thyroidectomy 2 years previously due to thyromegaly. The thyroidectomy specimen was at first interpreted as 'poorly differentiated carcinoma of the thyroid'. One year ago, she began to be aware of gingival swelling and loosening of teeth. A gum biopsy was taken and the pathologic features were similar to her 'thyroid carcinoma'. Subsequent investigations, including immunohistochemical stain, showed the gum was heavily infiltrated with histiocyte-like Langerhans' cells which were positive for S-100 protein. Ultrastructural examination of the cells under electron microscope revealed many typical intra-cytoplasmic Birbeck granules. Langerhans' cell histiocytosis was diagnosed. Langerhans' cell histiocytosis with thyroid involvement is extremely rare and may run a relatively indolent course. Even on a retrospective examination, it may easily be confused with poorly differentiated carcinoma of the thyroid. We suspect that this error may have been made on other occasions and that the occurrence of this condition may be underreported.   相似文献   
59.
M-mode echocardiographic findings were compared between sickle cell anemic and healthy children. Patients were composed of two groups; Group 1: mild group with no crises, no blood transfusions at the ages of 5.0 to 13.0, total of 12 children; Group 2: severe group, with frequent crises with requirement of blood transfusions at the ages of 3.0 to 13.0 years, total of 18 children. Control group was composed of 12 healthy children aged 5.0 to 13.0. When M-mode echocardiographic findings were compared, important findings were as follows: Mean left atrium dimension was increased both in the mild and severe groups (P < 0.001) compared with controls. This finding also supports the increase in the left ventricle end-diastolic dimension in both the severe and mild groups as compared with controls (P < 0.001). The increase in end-diastolic left ventricle dimension could be due to anemia present in the patients, but there was no difference between the two patient groups. Posterior left ventricle thickness and left ventricle mass was increased in both the mild and severe groups compared with controls (P < 0.001, P < 0.05), respectively. Left ventricular fractional shortening was more or less the same with controls. In spite of left ventricular volume load and dilatation, left ventricular contraction was good and systolic function was normal, and there was no correlation between the ECHO findings and hematological indices.  相似文献   
60.
Depletion neutropenia caused by overwhelming bacterial infection is associated with fatal outcome and is an objective indicator of the severity of sepsis. Studies on controlled evaluation of exchange transfusion in the management of severe neonatal sepsis have not considered neutropenia as an inclusion critcrion, and randomized, controlled trials on evaluation of ncutrophil functions after exchange transfusion are scarce. This prompted us to carry out the present study. Septicemic neonates were enrolled if they had neutropenia and were randomized to undergo exchange transfusion (study group, n = 20) or not (controls, n= 10). Granulocyte functions were assessed using the nitro blue tetrazolium (NBT) reduction test and the staphylococcicidal index. Blood was drawn for granulocyte function tests once from controls and donors, and before, immediately after and 6 h after exchange transfusion in the study group. Mortality was 35% in the study group and 70% in controls. Gram-negative organisms accounted for 80%, in the study group and 90% in controls. Mean total leukocyte count and neutrophil count increased significantly immediately after exchange transfusion and 6 h later. Absolute band count decreased significantly immediately after exchange transfusion and incrcased 6 h later. NBT reduction in septicemic neonates in the study group, as wclras in controls. was significantly decreascd as compared to donor cells. NBT reduction improved significantly immediately after exchange transfusion and 6 h later. The valucs of the perccntage of viable staphylococci recovered from neutrophils also improved significantly immediately after exchange transfusion and 6 h later. We conclude that exchange transfusion with fresh whole blood in severe neonatal septicemia with neutropenia improves survival, increases the neutrophil count and cnhances neutrophil function.  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