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   8573篇
  免费   857篇
  国内免费   88篇
耳鼻咽喉   89篇
儿科学   308篇
妇产科学   219篇
基础医学   1235篇
口腔科学   199篇
临床医学   1034篇
内科学   1810篇
皮肤病学   105篇
神经病学   599篇
特种医学   481篇
外科学   1209篇
综合类   186篇
一般理论   8篇
预防医学   835篇
眼科学   160篇
药学   440篇
中国医学   8篇
肿瘤学   593篇
  2021年   121篇
  2020年   79篇
  2019年   123篇
  2018年   131篇
  2017年   121篇
  2016年   124篇
  2015年   142篇
  2014年   175篇
  2013年   278篇
  2012年   346篇
  2011年   403篇
  2010年   219篇
  2009年   216篇
  2008年   338篇
  2007年   370篇
  2006年   330篇
  2005年   327篇
  2004年   265篇
  2003年   308篇
  2002年   279篇
  2001年   277篇
  2000年   333篇
  1999年   253篇
  1998年   186篇
  1997年   159篇
  1996年   145篇
  1995年   133篇
  1994年   131篇
  1993年   124篇
  1992年   217篇
  1991年   212篇
  1990年   180篇
  1989年   210篇
  1988年   202篇
  1987年   211篇
  1986年   167篇
  1985年   183篇
  1984年   132篇
  1983年   97篇
  1982年   80篇
  1981年   84篇
  1980年   79篇
  1979年   106篇
  1978年   95篇
  1977年   63篇
  1976年   76篇
  1975年   61篇
  1973年   66篇
  1972年   60篇
  1971年   62篇
排序方式: 共有9518条查询结果,搜索用时 15 毫秒
11.
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial.  相似文献   
12.
A total of 143 patients with superficial G2 (pTa, pT1) bladder cancer (48 G2pTa; 95 G2pT1) presenting between 1970 through 1987 were reviewed. Of 48 patients with G2pTa followed for up to eighteen years, G3 recurrence developed only in 1 (2.0%), and invasive cancer (greater than pT2) developed only in 2 (4.2%). They both received radiotherapy and have responded completely. There have been no cancer-related deaths. In contrast, in the 95 patients in whom the basement membrane had been breached (pT1), higher grade tumor (G3) developed in 11 (11.5%), and 15 (16%) had recurrences with invasion of muscle (greater than pT2). Among these there were 7 (7.3%) cancer-related deaths.  相似文献   
13.
14.
This breakout session at the Academic Emergency Medicine 2006 Consensus Conference examined how baseline overcrowding impedes the ability of emergency departments to respond to sudden, unexpected surges in demand for patient care. Differences between daily and catastrophic surge were discussed, and the need to invoke a hospital-wide response to surge was explored.  相似文献   
15.
16.
17.
Spontaneous regression of a desmoid tumour   总被引:2,自引:0,他引:2  
A 15-year-old girl presented with a very large desmoid tumour in her buttock; it extended into the pelvis and thigh and would have required hindquarter amputation for its removal. This was not performed and the tumour underwent spontaneous regression. Fourteen years later the patient is alive and well. The suggestion is made that in some cases a more expectant approach to treatment might be justified for what is essentially a non-malignant condition.  相似文献   
18.
To study the possible role of arginine vasopressin (AVP) in the control of haemostasis AVP infusions at 3 doses (0.1, 0.2 and 0.3 mU/kg/min) were performed in 6 male volunteers. Both plasma and platelet AVP concentrations rose in a dose-related manner. At doses of 0.2 and 0.3 mU/kg/min there was an increase in the plasma concentrations of both plasma Factor VIII and von Willebrand factor. The data support the hypothesis that AVP, by interacting with platelets and stimulating factor VIII and von Willebrand factor release, plays a role in the control of haemostasis.  相似文献   
19.
Abstract: We aimed to determine the alcohol consumption, blood alcohol levels (BALs) and subsequent driving of patrons leaving 15 hotels and taverns in Perth, Western Australia. Of the 414 patrons approached by interviewers on Friday and Saturday evenings, 307 (74 per cent) consented to take part. Self-reported alcohol consumption, driving intentions, perceived levels of fitness to drive and demographic information were collected using an interviewer-administered questionnaire. Observations of subsequent driving were recorded and BALs were measured by breath-alcohol meter. The patrons surveyed were predominantly male (76 per cent) and aged between 18 and 35 (87 per cent). Average reported alcohol consumption was 7.6 standard drinks for males and 4.9 drinks for females, around double the daily amount recommended by the National Health and Medical Research Council. Further, 23 per cent of the sample had consumed more than 10 drinks (male) and 6 drinks (female). With respect to BALs, 37 per cent of patrons exceeded the drink-drive limit then in force of 0.087 and 56 per cent exceeded 0.05. Of greater concern, 23 per cent who were over the 0.08 legal limit were subsequently observed to drive even though they had been informed of their BAL and legal status with respect to driving. The results suggest that most young patrons drinking in Perth metropolitan hotels and taverns consume alcohol on such occasions in excess of limits currently recommended by health authorities and attain blood alcohol levels dangerous for driving. This is likely to remain unchanged without public debate as to the responsibility of licensees in serving a potentially harmful psychotropic drug and effective enforcement of liquor licensing laws.  相似文献   
20.
The objectives of the studies described were to assess the ultrastructural neuropathology, blood-brain barrier (BBB) integrity and calcium status of the cerebellum of rats following a single dose of 750 mg · kg–1 l-2-chloropropionic acid (l-2-CPA). The first indications of intoxication appeared at 36 h when condensation of many granule cells associated with Purkinje cell degeneration and marked astroglial swelling were observed. Some electron-lucent granule cells were also noted lying amongst these condensed forms. Condensed granule cells had swollen, electron-lucent mitochondria, dilated Golgi apparatus and nuclear crenation. Occasionally, areas of granule cell necrosis were also present at this time. Granule cell condensation probably represents a preliminary and irreversible stage in an excitotoxic process that leads to necrosis. At 48 and 72 h, most granule cells were necrotic, and occasionally, extravasation of both erythrocytes and leucocytes into the expanded extravascular space was observed. Evaluation of the BBB by ultrastructural cytochemical visualisation of horseradish peroxidase injected i.v. 2 min before killing by perfusion fixation showed substantial leakage. At 36 h post-dose, ultrastructural calcium localisation using oxalate/pyroantimonate precipitation demonstrated a substantial increase in calcium pyroantimonate precipitate in mitochondria and other membranous cytoplasmic organelles (especially the Golgi apparatus) in condensed granule cells, but with little in their nuclei. However, their immediate neighbours (of ostensibly normal ultrastructural appearances) contained greater amounts of intranuclear precipitate. Swollen astroglial cells (especially the Bergmann glia) contained considerable quantities of precipitate. A possible excitotoxic mechanism via l-2-CPA-induced NMDA receptor agonism leading to overwhelming calcium influx and disruption of cellular calcium homeostasis is proposed. Received: 8 May 1996 / Revised: 1 September 1996 / Accepted: 11 September 1996  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