全文获取类型
收费全文 | 2179959篇 |
免费 | 150278篇 |
国内免费 | 3201篇 |
专业分类
耳鼻咽喉 | 31181篇 |
儿科学 | 71477篇 |
妇产科学 | 61990篇 |
基础医学 | 313498篇 |
口腔科学 | 61323篇 |
临床医学 | 189031篇 |
内科学 | 419121篇 |
皮肤病学 | 47232篇 |
神经病学 | 167660篇 |
特种医学 | 85962篇 |
外国民族医学 | 564篇 |
外科学 | 334576篇 |
综合类 | 45130篇 |
现状与发展 | 2篇 |
一般理论 | 544篇 |
预防医学 | 156214篇 |
眼科学 | 49881篇 |
药学 | 170181篇 |
8篇 | |
中国医学 | 4901篇 |
肿瘤学 | 122962篇 |
出版年
2018年 | 21342篇 |
2016年 | 18533篇 |
2015年 | 21047篇 |
2014年 | 28798篇 |
2013年 | 43167篇 |
2012年 | 59205篇 |
2011年 | 63169篇 |
2010年 | 37357篇 |
2009年 | 35070篇 |
2008年 | 60168篇 |
2007年 | 64875篇 |
2006年 | 65886篇 |
2005年 | 63811篇 |
2004年 | 61297篇 |
2003年 | 59357篇 |
2002年 | 57938篇 |
2001年 | 107107篇 |
2000年 | 109939篇 |
1999年 | 92496篇 |
1998年 | 24725篇 |
1997年 | 21963篇 |
1996年 | 22091篇 |
1995年 | 20869篇 |
1994年 | 19401篇 |
1993年 | 18099篇 |
1992年 | 72327篇 |
1991年 | 70391篇 |
1990年 | 69427篇 |
1989年 | 67133篇 |
1988年 | 61750篇 |
1987年 | 60347篇 |
1986年 | 57311篇 |
1985年 | 54263篇 |
1984年 | 39992篇 |
1983年 | 34331篇 |
1982年 | 19682篇 |
1981年 | 17380篇 |
1979年 | 36999篇 |
1978年 | 25494篇 |
1977年 | 22382篇 |
1976年 | 20369篇 |
1975年 | 22734篇 |
1974年 | 26632篇 |
1973年 | 25738篇 |
1972年 | 24580篇 |
1971年 | 22943篇 |
1970年 | 21201篇 |
1969年 | 20544篇 |
1968年 | 18837篇 |
1967年 | 16685篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
943.
944.
P J Landrigan M G Cherniack F A Lewis L R Catlett R W Hornung 《Scandinavian journal of work, environment & health》1986,12(1):32-39
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
945.
A prospective study was performed on seven male and eight female patients with normal hepatobiliary findings to investigate the effect of 20 mg nifedipine on cholecystokinin-induced gallbladder contraction. Each patient received 1 IDU (Ivy dog unit) cholecystokinin per kg body weight intravenously on two consecutive days, with additional administration of 20 mg nifedipine sublingually on the second day. Gallbladder volumes were assessed by ultrasonography over a period of 25 minutes. Cholecystokinin induced a maximal reduction in the mean initial volume of 56.8 +/- 3.6%. After nifedipine, this volume change was significantly reduced to 30.9 +/- 5.1% (p less than 0.001). Thus our data suggest for the first time that the calcium-channel-blocking agent nifedipine can have an effect on human gallbladder kinetics. 相似文献
946.
L Paris M Giardina R Pacifici S Pichini P Zuccaro G Sideri 《The Italian Journal of Neurological Sciences》1991,12(5):447-451
We compared two groups of patients with idiopathic epilepsy, 41 patients whose seizure frequency was not controlled by adequate therapy and 39 patients in good seizure control, in respect of hematology, kidney and liver function tests, serum IgG, IgA and IgM concentrations and drug concentrations. The only difference that emerged were in the serum immunoglobulins, which were raised in the drug refractory group, significantly (p less than 0.01) so in the case of IgG. Failure of seizure control did not depend on inadequacy of drug dose or of blood concentration. Although the serum Ig changes do not warrant the assumption of an immunological origin for drug resistance, they do suggest a useful research line. 相似文献
947.
M G Bartels C K Varley J Mitchell S J Stamm 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(1):100-103
Electrocardiograms were evaluated in 39 children and adolescents before and after the clinical use of imipramine and desipramine. The average increase in PR interval was 0.01 seconds. The PR interval increased by 0.02 seconds in 11 subjects, and a new first-degree atrioventricular block developed in two subjects. These changes were not related to the choice between imipramine and desipramine, the dose, or the method of administration. An increase in PR interval by 0.02 seconds or more did correlate with having an abnormality disclosed on a pretreatment electrocardiogram. The average increase in PR interval was 0.007 seconds for subjects with normal baseline electrocardiograms and 0.019 seconds for subjects with conduction and nonconduction abnormalities disclosed in baseline tracings. None of the electrocardiogram changes resulted in adverse clinical consequences. 相似文献
948.
R J Gatchel T G Mayer P Capra J Barnett P Diamond 《Archives of physical medicine and rehabilitation》1986,67(12):878-882
The present study evaluated the use of psychologic measures, in particular, the relatively new Million Behavioral Health Inventory (MBHI), in predicting change in physical function of chronic low back pain patients undergoing a functional restoration program. The first 134 consecutive patients completing this program were assessed. Results demonstrated that various clinical scales of the MBHI were predictive of improvement in physical function. In addition, various scales enabled discrimination between patients who completed the program and those who prematurely dropped out. Although this inventory shows promise in helping to predict response to treatment, no single psychologic test can reliably be used as the sole predictor in clinical cases. 相似文献
949.
Superficial bladder cancer: intravesical chemotherapy and tumour progression to muscle invasion or metastases 总被引:2,自引:0,他引:2
G Smith R A Elton G D Chisholm J E Newsam T B Hargreave 《British journal of urology》1986,58(6):659-663
Of 299 patients who presented with superficial bladder cancer (Ta, T1), 60 were treated by intravesical chemotherapy (Epodyl, methotrexate or mitomycin C). The rate of tumour progression to muscle invasion or metastases was identical for each intravesical regime. There was no evidence that mitomycin C promoted tumour progression. Carcinoma in situ in non-tumour-bearing urothelium was the most significant predictive factor for progression to muscle invasion or metastases. 相似文献
950.
M Altissimi R Antenucci C Fiacca G B Mancini 《Clinical orthopaedics and related research》1986,(206):202-210
The long-term results of the conservative treatment of wrist fractures were observed in a follow-up study of 297 cases over a period of one and one-half years to six years. The evaluation of the results was based on clinical parameters, both subjective and objective, as well as radiological features. The results were: excellent in 38% of cases, good in 49%, fair in 11.5%, and poor in 1.5%; considerably worse were the subjective results (20% fair to poor). No statistically significant relation could be found between results and type of fracture. Clinical deformities and pain in the area of the distal radioulnar joint were frequent. Decrease in grip strength was observed in 17.8% of cases. A limitation of wrist movement was not frequent. Numerous compressive neuropathies were found (41 in 35 patients), especially of the median nerve. The values relative to the three radiographic parameters under investigation (that is, radial deviation, volar tilt, and radioulnar index) were often found to be out of the normal range. The comparative study of postreduction and follow-up radiograms show the loss of reduction to be frequent, especially as far as the volar tilt is concerned. The frequent radiologic deformities are associated with significantly bad results only in cases of extremely abnormal values. However, fractures of the distal radius are not to be underestimated. Long-term results following conservative treatment may not be as acceptable as is generally assumed. 相似文献