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   2887篇
  免费   169篇
  国内免费   9篇
耳鼻咽喉   11篇
儿科学   55篇
妇产科学   54篇
基础医学   355篇
口腔科学   77篇
临床医学   184篇
内科学   869篇
皮肤病学   45篇
神经病学   218篇
特种医学   133篇
外科学   459篇
综合类   6篇
预防医学   112篇
眼科学   43篇
药学   162篇
中国医学   1篇
肿瘤学   281篇
  2022年   32篇
  2021年   42篇
  2020年   27篇
  2019年   29篇
  2018年   40篇
  2017年   45篇
  2016年   45篇
  2015年   54篇
  2014年   63篇
  2013年   70篇
  2012年   110篇
  2011年   125篇
  2010年   78篇
  2009年   76篇
  2008年   111篇
  2007年   115篇
  2006年   103篇
  2005年   125篇
  2004年   117篇
  2003年   111篇
  2002年   117篇
  2001年   131篇
  2000年   163篇
  1999年   125篇
  1998年   35篇
  1997年   38篇
  1996年   26篇
  1995年   27篇
  1994年   22篇
  1993年   31篇
  1992年   64篇
  1991年   67篇
  1990年   59篇
  1989年   70篇
  1988年   65篇
  1987年   64篇
  1986年   62篇
  1985年   52篇
  1984年   41篇
  1983年   24篇
  1981年   14篇
  1979年   20篇
  1978年   22篇
  1977年   15篇
  1974年   24篇
  1973年   19篇
  1971年   18篇
  1969年   18篇
  1968年   16篇
  1966年   13篇
排序方式: 共有3065条查询结果,搜索用时 15 毫秒
1.
2.
3.
Summary Cranial computed tomography (CT) of 108 cases with dilated lateral ventricles was reviewed to elucidate the relationship between focal vulnerability of developing brain and disproportional dilatation of lateral ventricles. CT findings of 108 cases with symmetrical dilatation of lateral ventricles were classified into three types by morphometry of lateral ventricles: anterior horn predominant type (31 cases), diffuse type (36 cases), posterior horn predominant type (41 cases). Posterior horn predominant type has a tendency to occur in congenital anomalies and premature brain damage, and anterior horn predominant type in infantile brain damage. This disproportional dilatation of anterior or posterior horns suggests a vulnerability of periventricular structure in developing brain.  相似文献   
4.
The aim of this study was to clarify and compare the temporal course of bone mineral density (BMD) between fast bone losers and normal residents in Miyama Village, a rural Japanese community. BMD was measured over a 10-year period in a cohort study in Miyama Village, Wakayama Prefecture, Japan, to provide information on rate of bone loss in the mature and elderly population. Subjects (n=400) were selected by sex and age stratum from the full list of residents born in 1910–1949, with 50 men and 50 women in each age decade. Baseline BMD of the lumbar spine and proximal femur was measured using dual energy X-ray absorptiometry in 1990, 1993, 1997 and 2000. In the cohort, 171 men and 189 women completed the follow-up survey performed in 1993. After calculating the rate of bone loss between 1990 and 1993, the greatest tertile from the distribution of bone loss was categorized as fast bone losers, with the remainder considered as normal subjects. Changes in BMD were compared between normal subjects and fast bone losers over the 10-year period. Mean rate of change for BMD at both lumbar spine and femoral neck in fast bone losers recovered to levels similar to those in normal subjects over 7 years of observation. By contrast, BMD at the lumbar spine and femoral neck decreased steeply over the 10-year period in both groups, and mean BMD for fast bone losers was significantly lower than that of normal subjects (P<0.05). These differences were apparent only at the lumbar spine in both men and women, even after adjusting for age. These results indicate that fast bone loss is a transient phenomenon rather than a fixed status, although individuals who have been categorized as fast bone losers at some stage continue to display low BMD in the lumbar spine.  相似文献   
5.
Renal cell carcinoma (RCC) causes many kinds of symptoms such as hypercalcemia, hypertension, polycythemia and fever. Here we describe a rare case of RCC presenting with a persistent cough. After radical nephrectomy, the obstinate cough disappeared. When the tumor recurred locally, the cough also recurred. Furthermore, the cough disappeared completely again after the removal of the recurrent tumor. Although all the clinical findings suggested that the RCC caused the cough, we could not identify a specific humoral substance responsible for the cough.  相似文献   
6.
7.
Fourteen patients with invasive bladder cancer were treated by bilateral internal iliac artery infusion of cisplatin, with or without other anticancer agents, and concurrent radiotherapy. Angiotensin II was simultaneously infused in 10 cases. Of the 14 patients, complete response and partial response were achieved in 9 (64%) and 3, respectively. Hematuria was controlled in all 8 patients, and pain was relieved in 3 of 4 patients. Side effects were observed in 8 patients: appetite loss in 8, nausea and/or vomiting in 7, and leukocytopenia in 6 patients, in 3 of whom radiotherapy had to be intermittent because of severe leukocytopenia (less than 2000/mm3). However, restoration of leukocytopenia occurred one week later. Thus, intra-arterial anticancer agents including cisplatin together with concurrent radiation may be one of the most effective therapies for invasive bladder cancer.  相似文献   
8.
Prognostic significance of histologic parameters of soft tissue sarcomas.   总被引:3,自引:0,他引:3  
BACKGROUND AND METHODS. A univariate and multivariate analysis for the correlation between histomorphologic factors and prognosis was made using data from 1116 patients with soft tissue sarcoma, including 1005 cases available with complete histologic and follow-up data. RESULTS. The overall 5-year survival rate was 43.6%. The univariate analysis using Kaplan-Meier survival curves showed that tumor differentiation, cellularity, nuclear atypia, cellular pleomorphism, mitotic activity, amount of fibrous stroma, extent of myxoid areas, extent of tumor necrosis, and histologic grading (determined by the estimated range of malignancy for each type of sarcoma using a reported guideline) were all significant prognostic factors in the overall soft tissue sarcoma group. By a multivariate analysis using a procedure based on the Weibull model to failure data, the histologic grading and extent of tumor necrosis were proved to be prognostically significant in the overall sarcoma group. However, after additional analysis on each histologic type of sarcoma, it was determined that both tumor necrosis and histologic grading were applicable in only two types: malignant fibrous histiocytoma and leiomyosarcoma. Liposarcoma, synovial sarcoma, and malignant schwannoma each also showed some determinable factor of prognostic significance. CONCLUSIONS. It was concluded that there seemed to be no single universal prognostic parameter that could be applied to each soft tissue sarcoma type. These results suggest that the predictive significance of the various histologic parameters should be based on each specific type of sarcoma.  相似文献   
9.
We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.  相似文献   
10.
Background: Pancreatic carcinoma is one of the most lethal cancers. Because pancreatic carcinoma is still very difficult to diagnose in its early stage, many of these patients will be considered unsuitable for surgery. If a cytological diagnosis is obtained at initial endoscopic retrograde cholangiopancreatography (ERCP), suitable treatment will be initiated without delay. Methods: To increase the number of exfoliated cells from the pancreatic duct, we devised a new technique, pancreatic duct lavage fluid (PDLF), following bronchoalveolar lavage fluid. The present paper reports the effectiveness of cytological examination using PDLF in the diagnosis of pancreatic carcinoma. We examined 18 pancreatic carcinoma cases. After the endoscopic retrograde pancreatography (ERP), PDLF was collected from a double‐lumen catheter inserted into the main pancreatic duct. Saline injected from the lumen for the injection, and PDLF was aspirated from the other lumen for the guidewire at the same time. The cytological examination was performed using PDLF. Results: Exfoliated cells were more frequently found in PDLF from all patients. In 15 cases (83%), cytological examination of PDLF revealed positive cytological results as the diagnosis of pancreatic carcinoma. Conclusion: Cytological examination using PDLF has a high sensitivity for detection of pancreatic carcinoma. The new examination, PDLF, is simple, safe and effective, so we expect PDLF to become widely popular.  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