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   3207433篇
  免费   249965篇
  国内免费   5793篇
耳鼻咽喉   46644篇
儿科学   102766篇
妇产科学   86606篇
基础医学   453089篇
口腔科学   91555篇
临床医学   290137篇
内科学   626072篇
皮肤病学   67328篇
神经病学   264778篇
特种医学   126599篇
外国民族医学   1301篇
外科学   482400篇
综合类   74413篇
现状与发展   2篇
一般理论   1255篇
预防医学   258914篇
眼科学   74989篇
药学   240119篇
  6篇
中国医学   6119篇
肿瘤学   168099篇
  2018年   34541篇
  2017年   26122篇
  2016年   28631篇
  2015年   32382篇
  2014年   45722篇
  2013年   69898篇
  2012年   95848篇
  2011年   101176篇
  2010年   59451篇
  2009年   56286篇
  2008年   95492篇
  2007年   101805篇
  2006年   102243篇
  2005年   99520篇
  2004年   96170篇
  2003年   92899篇
  2002年   91164篇
  2001年   146836篇
  2000年   152065篇
  1999年   128862篇
  1998年   37274篇
  1997年   33723篇
  1996年   33598篇
  1995年   32370篇
  1994年   30342篇
  1993年   28339篇
  1992年   103446篇
  1991年   100584篇
  1990年   97163篇
  1989年   93543篇
  1988年   86621篇
  1987年   85366篇
  1986年   80602篇
  1985年   77100篇
  1984年   58466篇
  1983年   49772篇
  1982年   29896篇
  1981年   26843篇
  1979年   54526篇
  1978年   38148篇
  1977年   32290篇
  1976年   30349篇
  1975年   32265篇
  1974年   39426篇
  1973年   37559篇
  1972年   35000篇
  1971年   32192篇
  1970年   30547篇
  1969年   28283篇
  1968年   25754篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Intrathecal morphine for post-thoracotomy pain   总被引:1,自引:0,他引:1  
We wished to investigate possible differences in the duration of postoperative analgesia and the incidence of respiratory depression after the intrathecal injection in the lumbar area of 10 micrograms/kg morphine in hypobaric and hyperbaric solution for relief of post-thoracotomy pain. Twenty-nine patients received morphine plus dextrose (hyperbaric) and 21 received morphine in preservative-free normal saline. The duration of analgesia was longer with the morphine in the normal saline group than in the hyperbaric group (P less than 0.04). One patient developed delayed respiratory depression. Our data support the use of morphine in normal saline mixtures for greater duration of analgesia after thoracic operations.  相似文献   
992.
993.
S E Bedell  D Pelle  P L Maher  P D Cleary 《JAMA》1986,256(2):233-237
We studied compliance with do-not-resuscitate (DNR) orders at a university hospital where a DNR protocol has existed since 1979. Documentation of DNR status in patient progress notes and chart orders increased through 1983. During a 12-month period (March 1983 through April 1984), we studied in detail the medical records of 521 patients who had a cardiopulmonary arrest in the hospital. Seventy-five percent (389 of 521) of these patients were designated DNR. Patients who were designated DNR were significantly more likely to be older, to have malignancy or an abnormal mental status, and to be less likely to have acute myocardial infarction, stroke, or chronic obstructive pulmonary disease than patients in whom resuscitation was attempted. Eighty-six percent of families, but only 22% of patients, were involved in the decision to designate a patient DNR. The decision to designate a patient DNR occurred late in the course of a patient's illness, often when the patient was in coma. For 28% of patients, some form of medical care was withdrawn or withheld after they were designated DNR. These data suggest that use of the DNR protocol requires changes if patients are to participate in the decision not to undergo cardiopulmonary resuscitation.  相似文献   
994.
995.
996.
    
Zusammenfassung 103 Patienten wurden wegen akuter spontaner oder nach Trauma persistierender Scrotalschmerzen behandelt. 62mal wurde diagnostisch freigelegt. Die intraoperativen Befunde (32 Torsionen, 12 stielgedrehte Hydatiden, 3 Hodennekrosen, 3 Hodenrupturen, 7 komprimierende Haematome, 5 Epididymitiden) bestätigten unsere Indikationsstellung zur chirurgischen Exploration: Plötzlicher Spontanschmerz, vor allem beim jugendlichen Patienten, anhaltender Schmerz nach Hodenprellung und alle Zweifelsfälle! Ohne Alternative spart der komplikationslose und schnelle diagnostisch-chirurgische Eingriff Zeit für das gefährdete Organ bei simultaner Therapiemöglichkeit.  相似文献   
997.
The effects of labeling a person as hypertensive have important implications for hypertension screening. The Hypertension Detection and Follow-up Program (HDFP) provides an opportunity to examine the effects of labeling, treatment, and study assignment on a large group of hypertensives (n = 10,070). Their answers to questions regarding perceived health and general well-being asked at baseline and again one year later were analyzed. There was no significant change in the perceived health status of persons who were unaware of their hypertension at baseline and remained untreated at one year (labeling alone). The effect of labeling plus treatment was associated with a significant decrease in perceived health. The effect of antihypertensive drug therapy on perceived health status was examined in persons who were aware of their hypertension but not on treatment at baseline, and on treatment at one year. The stepped care group (SC) had a significant improvement in their perceived health and a significant decrease in the amount of time spent worrying about their health. The referred care group (RC) had no change. Program assignment effects were studied in individuals aware of their hypertension and on treatment both at baseline and one year later. Both the SC and RC groups had a significant improvement in their perceptions of their health status. The SC group had a significant decrease in time spent worrying about their health, while the RC group showed no change. These reassuring results fail to support the suggestion that labeling persons as hypertensive is necessarily followed by negative psychological consequences.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
998.
In medical studies with censored data Kaplan and Meier's product limit estimator has frequent use as the estimate of the survival function. Simultaneous confidence intervals for the survival function at various time points constitute a useful addition to the analysis. This study compares several such methods. We consider in a simulation investigation two whole curve confidence bands and four methods based on the Bonferroni inequality. The results show that three Bonferroni-type methods are essentially equivalent, all being better than the other methods when the number of time points is small (3 or 5).  相似文献   
999.
Button wiring has been used as an alternative to eyelet wiring in the Department of Oral and Dental Surgery of Birmingham General Hospital since 1977. This clinical update reviews 65 patients with mandibular fractures in which button wires were utilised in their treatment.  相似文献   
1000.
An industrial hygiene and medical survey was conducted in an iron foundry to study the occurrence of silicosis. Breathing zone exposures to respirable crystalline silica had been very high in 1977 [1 045 micrograms/m3 (geometric mean) for coremakers and 198 micrograms/m3 for fettlers]; exposures in 1980 and 1982 were substantially lower. A radiographic evaluation of 188 workers revealed silicosis in 18 (9.6%). Eight had category 1 profusion of small rounded pulmonary lesions (by the 1980 classification of the International Labour Office); two had category 2; and eight had category 3. Two had progressive massive fibrosis. Four workers without silicosis in 1977 had developed lesions by 1980. The prevalence increased from 1.5% among workers employed less than 20 years to 53% among longer term workers. No association was found between the prevalence of silicosis and cigarette smoking. Chronic cough was more common in workers with heavy current dust exposure than in those with light exposure, more common in smokers than in nonsmokers, and more common in silicotics than in nonsilicotics. A multiplicative interaction existed between dust exposure and smoking in the etiology of cough. Silicosis continues to exist in American foundries. Cigarette smoking does not contribute to the causation of silicosis, but it aggravates the attendant respiratory symptoms.  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