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   3452473篇
  免费   248087篇
  国内免费   6160篇
耳鼻咽喉   47046篇
儿科学   112678篇
妇产科学   94074篇
基础医学   498979篇
口腔科学   98331篇
临床医学   313838篇
内科学   664718篇
皮肤病学   77045篇
神经病学   272479篇
特种医学   129219篇
外国民族医学   693篇
外科学   518518篇
综合类   76029篇
现状与发展   14篇
一般理论   1255篇
预防医学   267497篇
眼科学   82747篇
药学   254907篇
  13篇
中国医学   7550篇
肿瘤学   189090篇
  2021年   26937篇
  2019年   27816篇
  2018年   39089篇
  2017年   29510篇
  2016年   32967篇
  2015年   37222篇
  2014年   52437篇
  2013年   78254篇
  2012年   107952篇
  2011年   114437篇
  2010年   68287篇
  2009年   64051篇
  2008年   106866篇
  2007年   113858篇
  2006年   115127篇
  2005年   111097篇
  2004年   106863篇
  2003年   102445篇
  2002年   98897篇
  2001年   163022篇
  2000年   167369篇
  1999年   140365篇
  1998年   39878篇
  1997年   34873篇
  1996年   35056篇
  1995年   33256篇
  1994年   30576篇
  1993年   28585篇
  1992年   108257篇
  1991年   105217篇
  1990年   101954篇
  1989年   98367篇
  1988年   90205篇
  1987年   88293篇
  1986年   83057篇
  1985年   79492篇
  1984年   59013篇
  1983年   50290篇
  1982年   29365篇
  1979年   53690篇
  1978年   37854篇
  1977年   31792篇
  1976年   30147篇
  1975年   32054篇
  1974年   38829篇
  1973年   37186篇
  1972年   34708篇
  1971年   32635篇
  1970年   30279篇
  1969年   28634篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
In patients with Type 2 diabetes, the appropriate intensity of glucose control is determined by age, life expectancy, and the presence of concomitant disease. Geriatric patients are especially susceptible to hypoglycaemia and therefore particular care should be taken in this group characterized by polypharmacy, renal or hepatic dysfunction, cardiovascular multimorbidity and malnutrition. As hypoglycaemia is a significant cause of morbidity and mortality, treatment regimens for diabetes should minimize the occurrence of hypoglycaemic episodes and be tailored to the patient's individual needs. The pharmacological options for treating Type 2 diabetes have increased considerably and the risk of hypoglycaemia of the currently available drugs varies considerably. Metformin, thiazolidinediones, and acarbose, oral antidiabetic drugs that decrease insulin resistance or postprandial glucose absorption, are associated with a low risk of hypoglycaemia. These drugs can also be used effectively in various combination regimens; however, by improving insulin sensitivity, combinations of metformin and thiolidinediones with sulphonylureas or meglitinides may considerably increase the risk of hypoglycaemia. On account of its complex pharmacoprofile glibenclamide is a problematic substance carrying a high risk of hypoglycaemia. There are limited preliminary data indicating that, under routine conditions, glimepiride may be associated with a lower risk of hypoglycaemia than glibenclamide and is no more likely to cause hypoglycaemia than other shorter-acting agents such as gliclazide and glipizide. Nateglinide and repaglinide as short-acting insulin secretagogues may be associated with a reduced risk of hypoglycaemia compared with glibenclamide, in particular when dosed flexibly. Repaglinide might be beneficial in individuals with renal impairment.  相似文献   
74.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
75.
76.
BACKGROUND: Repairing dorsal nasal defects is a frequent challenge for dermatologic surgeons, mainly due to the high frequency of basal cell carcinomas on this site. Obvious scars, mismatched skin and distortion of the nasal contour are the surgical hazards that must be avoided in these cases. AIM: Our aim was to perform surgery involving a simple flap in order to repair medium to large defects on the dorsal side of the nose. METHODS: The dorsal horizontal advancement flap was studied in 12 patients, in order to evaluate the benefits and limits of this surgical procedure. RESULTS: The resulting scars on most of our patients were well-camouflaged among their natural skin lines, and there was neither distortion of the alar contour nor the nostril. CONCLUSIONS: This flap is easy to perform and, in selected cases, provides an outstanding alternative to second-intention healing, full-thickness skin grafts, transposition, rotation and pedicle flaps.  相似文献   
77.
78.
PURPOSE: The aim of this study was to determine if the concomitant use of ketorolac 0.4% and cyclosporin-A improves patient comfort during the induction phase in treating chronic dry eye disease. METHODS: Patients (n = 52) with clinically diagnosed dry eye were randomized to receive either cyclosporin-A monotherapy twice-daily (BID) or a BID adjunctive regimen of ketorolac, followed by the instillation of cyclosporin-A 10 min later. Study visits were at baseline, week 2, and week 6. At each study visit, patients underwent an evaluation for corneal staining, Schirmer's scores, and tear break-up time tests. Patients were asked to rate ocular comfort on a 4-point scale and to complete the ocular surface disease index (OSDI). Changes from baseline readings were recorded at week-2 and week-6 visits, and final patient success on treatment regimen was evaluated at week 6. RESULTS: After 6 weeks, the mean ocular comfort score of adjunctive patients improved 2.55 +/- 0.95 points, versus 1.53 +/- 0.91 points for monotherapy (P = 0.309). The adjunctive regimen provided significantly greater corneal staining reductions versus monotherapy, mean reduction in staining of 1.74 +/- 0.9, versus 1.27 +/- 0.56 (P = 0.044). CONCLUSIONS: Concurrent ketorolac 0.4% use with cyclosporin-A significantly reduced corneal staining and increased comfort in the induction phase.  相似文献   
79.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
80.
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