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   1223篇
  免费   47篇
  国内免费   19篇
耳鼻咽喉   15篇
儿科学   51篇
妇产科学   15篇
基础医学   130篇
口腔科学   17篇
临床医学   79篇
内科学   200篇
皮肤病学   7篇
神经病学   248篇
特种医学   197篇
外科学   108篇
综合类   10篇
预防医学   39篇
眼科学   65篇
药学   50篇
中国医学   1篇
肿瘤学   57篇
  2022年   11篇
  2021年   15篇
  2020年   12篇
  2019年   7篇
  2018年   23篇
  2017年   14篇
  2016年   27篇
  2015年   25篇
  2014年   30篇
  2013年   42篇
  2012年   58篇
  2011年   64篇
  2010年   33篇
  2009年   35篇
  2008年   54篇
  2007年   80篇
  2006年   66篇
  2005年   65篇
  2004年   35篇
  2003年   42篇
  2002年   28篇
  2001年   31篇
  2000年   22篇
  1999年   26篇
  1998年   33篇
  1997年   22篇
  1996年   31篇
  1995年   23篇
  1994年   25篇
  1993年   19篇
  1992年   11篇
  1991年   20篇
  1990年   19篇
  1989年   25篇
  1988年   34篇
  1987年   22篇
  1986年   26篇
  1985年   19篇
  1984年   16篇
  1983年   12篇
  1982年   12篇
  1981年   4篇
  1980年   12篇
  1979年   4篇
  1977年   10篇
  1976年   8篇
  1974年   4篇
  1973年   5篇
  1972年   7篇
  1969年   4篇
排序方式: 共有1289条查询结果,搜索用时 15 毫秒
1.
2.
3.
Cavernous angiomas, also called cavernous malformations or cavernomas, are vascular hamartomas accounting for 3–16% of all angiomatous lesions of the spinal district. Although histologically identical, these vascular anomalies may exhibit different clinical behavior and radiological features, depending on their location, hinting at different managements and therapeutic approaches. The authors report 11 cases of symptomatic spinal cavernous angiomas diagnosed and surgically treated over the past 18 years. Age of patients ranged from 15–75 years; males outnumbered females. Three patients had vertebral cavernous malformations, secondarily invading the epidural space; two had pure epidural lesions; two patients had intradural extramedullary lesions, and four intramedullary lesions. Surgical removal was completely achieved in four patients with intramedullary lesions, in two with subdural extramedullary lesions, and in one with a pure epidural lesion. Subtotal excision of another one epidural and three vertebral cavernous angiomas was followed by radiotherapy. There was no morbidity related to surgery; the mean follow-up was 2 years. The outcome was excellent in two cases, good in six, and unchanged in the other three. The authors discuss the different modalities of treatment of these vascular lesions variously placed along the spine.  相似文献   
4.
BACKGROUND: Asking psychiatric in-patients about their drug consumption is unlikely to yield reliable results, particularly where alcohol and illicit drug use is involved. The main aim of this study was to compare spontaneous self-reports of drug use in hospitalized psychiatric patients to biological measures of same. A secondary aim was to determine which personal factors were associated with the use of tobacco, alcohol, and illicit drugs as indicated by these biological measures. METHODS: The consumption of substances was investigated using biological measures (urine cotinine, cannabis, opiates, cocaine, amphetamines and barbiturates; blood carbohydrate-deficient transferrin [CDT] and gamma-glutamyl transferase [GGT]) in 486 consecutively admitted psychiatric patients, one day following their hospitalization. Patients' self-reports of alcohol, tobacco and illicit drugs consumption were recorded. Socio-professional and familial data were also recorded. RESULTS: The results show a low correlation between biological measures and self-reported consumption of alcohol and illicit drugs. Fifty-two percent of the patients under-reported their consumption of illicit drugs (kappa=.47). Patients with schizophrenia and personality disorders were more likely to disclose their illicit drug consumption relative to patients suffering from mood disorders and alcohol dependence. Fifty-six percent of patients underreported alcohol use, as evaluated by CDT (kappa=.2), and 37% underreported when using the CDT+GGT measure as an indicator. Smoking appeared to be reported adequately. In the study we observed a strong negative correlation between cannabis use and age, a strong correlation between tobacco and cannabis use, and correlations between tobacco, cannabis and alcohol consumption. CONCLUSION: This study is the first to compare self-reports and biological measures of alcohol, tobacco and illicit drug uses in a large sample of inpatients suffering from various categories of psychiatric illnesses, allowing for cross-diagnosis comparisons.  相似文献   
5.
Chitambar  CR; Zivkovic  Z 《Blood》1989,74(2):602-608
Information regarding transferrin (Tf) receptor degradation is largely incomplete. HL60 cells were shown to release to their growth medium a Tf-binding protein which could be immunoprecipitated by anti-Tf receptor monoclonal antibodies (MoAbs) B3/25 and OKT9. Soluble Tf receptor was detected in the medium within one hour of replating of cells, and its release was inhibited at 4 degrees C. The affinity of Tf for the soluble receptor released by cells (kd = 2.3 x 10(-10) mol/L) was slightly lower than its affinity for the detergent-solubilized cellular receptor (kd = 1.2 x 10(-10) mol/L). 125I-Tf internalized and released by cells subsequently bound to Tf receptor released by the same cells, and soluble Tf receptor in the conditioned medium (CM) inhibited 125I-Tf binding to intact cells. The soluble Tf receptor isolated from the CM was smaller (78,000 daltons) than the cell surface receptor (94,000 daltons) when analyzed by gel electrophoresis under reducing conditions. Isolated cell membranes readily released soluble receptor; however, this release could be blocked by protease inhibitors. The soluble Tf receptor may represent the extracytoplasmic domain of the cellular Tf receptor released from the surface of HL60 cells through proteolytic cleavage by a membrane-based protease.  相似文献   
6.
7.
Arteriovenous malformations (AVMs) of the spinal cord are a rare occurrence in the pediatric age group. This report describes the successful, complete removal of such a lesion in a boy age 12. The clinico-radiological findings and different treatment modalities of these entities are reviewed.  相似文献   
8.
Padovani  A.  Costanzi  C.  Gilberti  N.  Borroni  B. 《Neurological sciences》2006,27(1):s40-s43
Neurological Sciences - Parkinson’s disease (PD) is one of the most common neurodegenerative disorders, affecting about 1% of the population over the age of 60. In addition to motor...  相似文献   
9.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  相似文献   
10.
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