全文获取类型
收费全文 | 524120篇 |
免费 | 33900篇 |
国内免费 | 645篇 |
专业分类
耳鼻咽喉 | 7012篇 |
儿科学 | 17145篇 |
妇产科学 | 13685篇 |
基础医学 | 86309篇 |
口腔科学 | 14850篇 |
临床医学 | 45026篇 |
内科学 | 95943篇 |
皮肤病学 | 12353篇 |
神经病学 | 36881篇 |
特种医学 | 18908篇 |
外国民族医学 | 63篇 |
外科学 | 78870篇 |
综合类 | 8524篇 |
一般理论 | 119篇 |
预防医学 | 39186篇 |
眼科学 | 12268篇 |
药学 | 41205篇 |
中国医学 | 1047篇 |
肿瘤学 | 29271篇 |
出版年
2018年 | 5147篇 |
2016年 | 4290篇 |
2015年 | 4727篇 |
2014年 | 6324篇 |
2013年 | 9846篇 |
2012年 | 13299篇 |
2011年 | 14732篇 |
2010年 | 8562篇 |
2009年 | 8002篇 |
2008年 | 14081篇 |
2007年 | 15136篇 |
2006年 | 15385篇 |
2005年 | 14806篇 |
2004年 | 14487篇 |
2003年 | 13821篇 |
2002年 | 13741篇 |
2001年 | 24463篇 |
2000年 | 25480篇 |
1999年 | 20877篇 |
1998年 | 5563篇 |
1997年 | 4801篇 |
1996年 | 5144篇 |
1995年 | 4718篇 |
1994年 | 4400篇 |
1992年 | 16026篇 |
1991年 | 16557篇 |
1990年 | 16634篇 |
1989年 | 16027篇 |
1988年 | 14766篇 |
1987年 | 14588篇 |
1986年 | 13747篇 |
1985年 | 13149篇 |
1984年 | 9757篇 |
1983年 | 8333篇 |
1982年 | 4590篇 |
1981年 | 4254篇 |
1979年 | 9478篇 |
1978年 | 6885篇 |
1977年 | 5819篇 |
1976年 | 5622篇 |
1975年 | 6428篇 |
1974年 | 7682篇 |
1973年 | 7177篇 |
1972年 | 6990篇 |
1971年 | 6728篇 |
1970年 | 6212篇 |
1969年 | 5928篇 |
1968年 | 5600篇 |
1967年 | 5050篇 |
1966年 | 4485篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Factors associated with levels of physical activity at work and during leisure time were analyzed among 577 subjects who had been selected as population controls for a case-control study by random selection from telephone directories. The intensity of physical activity at work was inversely associated with body mass index, the proportion of professionals & managers, consumption of western style breakfast, coffee, butter/margarine, and whisky; and positively associated with rice intake. Frequency of physical activities during leisure time was positively associated with consumption of vegetables, fruits, mushrooms, milk, cheese and coffee, and moderation in eating; and inversely associated with rice intake and the prevalence of gastrointestinal symptoms and medication. The association of physical activity with these factors should be considered in studying its relationship to disease risk. 相似文献
32.
C.I.V. FRANKLIN 《Journal of Medical Imaging and Radiation Oncology》1992,36(1):44-47
This paper examines the effect of patient age, tumour grade and extent of surgery on the outcome of treatment of 278 patients with high grade malignant gliomas referred to the Queensland Radium Institute between 1980 and 1987. The aim was to determine whether the extent of surgical resection alters survival rates. The extent of surgery had no effect on survival except for those patients with grade 3 tumours in whom a total excision was possible. Those in whom only a biopsy was done did not have a worse prognosis. Grading was found to be of importance, as patients with grade 3 tumours had a better survival than those with grade 4 tumours. In grade 4 tumours, those under 30 years of age had a better survival than those over 30 years, whereas with grade 3 tumours there was a gradation of age effect (under 40 years best, then 40–49 years, and those 50 years and over doing worst). 相似文献
33.
34.
35.
36.
Three hundred and twenty samples of subgingival plaque were obtained from 80 caucasian girls, ranging from 10 to 13 years of age. The samples were analyzed to verify the influence of age upon colonization of the gingival sulcus by microorganisms potentially pathogenic to the periodontal tissues. The gingival and plaque status were evaluated through the gingival index (GI) and plaque index (PlI) and the microflora was assessed by the enzymatic method benzoyl-arginine-naphthylamide (BANA). The results of the BANA test were positive for 62.50% of the tested individuals and 40% of the examined sites. The influence of age was statistically significant on BANA reactivity, and the number of positive sites was greater at 11 (57.5%) than at 12 years (28.8%). 相似文献
37.
38.
Variations of the medial and inferior choanal limits may facilitate snoring. These are: 1) short vomer without crista choanalis vomeris and adaptational formations, 2) extremely concave posterior margin of the hard palate leading to disproportion between the muscular and aponeurotic part of m. tensor veli palatini and hence to a flabby soft palate especially during sleep, and 3) neonatal relation of the height and width of the choane resulting in a very large choanal region instead of relative reduction of choanal width compared to its increasing height. All these variations result in a flabby soft palate especially during sleep and may lead to formation of whirles of inspired air and snoring. 相似文献
39.
Most authors consider the principal advantage of FG anastomoses (compared to microsurgical anastomoses) to be shorter operating time, reduced surgical trauma to oviduct stumps, and absence of tissue ischemia. These features promote reparative regeneration and decrease adhesion formation, resulting in complete recanalization of fallopian tubes. To date, the majority of work on FG is confined to the experimental development of surgical techniques. Investigations in reconstructive gynecological surgery are quite uncommon. The physical properties of FG and the positive results of available experimental studies suggest that further development of surgical techniques using FG in obstetrics and gynecology is worthwhile. 相似文献
40.
D.-Y. LIN I.-S. SHEEN C.-M. CHU & Y.-F. LIAW 《Alimentary pharmacology & therapeutics》1996,10(6):961-966
Background : The clinical course of chronic hepatitis B is variable. Patients with hepatic decompensation, bridging necrosis or an alpha-fetoprotein level greater than 100 ng/mL during an exacerbation of hepatitis have a high risk of developing cirrhosis. This study was conducted to evaluate the effect of colchicine in the prevention of cirrhosis in such patients.
Methods : Patients with risk factor(s) were randomized to receive either colchicine 5 mg/week or no specific treatment, the end point being development of cirrhosis.
Results : After a follow up period of 4 years, the treatment group had a marked reduction in exacerbations of acute hepatitis (32% vs. 63%/patient/year, P <0.005). Seven out of 38 patients in the treatment group and 10 out of 27 patients in the control group developed cirrhosis. The calculated cumulative incidence of cirrhosis by the end of first, second, third and fourth years in the treatment group was 8.7, 18.6, 32 and 32%, respectively. The corresponding figures in the control group were 30, 35.5, 46.3 and 73.2%, respectively, with a P -value of 0.057.
Conclusions : The results suggest that colchicine may prevent cirrhosis in chronic hepatitis B patients with risk factor(s), possibly by suppressing exacerbations of hepatitis through an anti-inflammatory effect. 相似文献
Methods : Patients with risk factor(s) were randomized to receive either colchicine 5 mg/week or no specific treatment, the end point being development of cirrhosis.
Results : After a follow up period of 4 years, the treatment group had a marked reduction in exacerbations of acute hepatitis (32% vs. 63%/patient/year, P <0.005). Seven out of 38 patients in the treatment group and 10 out of 27 patients in the control group developed cirrhosis. The calculated cumulative incidence of cirrhosis by the end of first, second, third and fourth years in the treatment group was 8.7, 18.6, 32 and 32%, respectively. The corresponding figures in the control group were 30, 35.5, 46.3 and 73.2%, respectively, with a P -value of 0.057.
Conclusions : The results suggest that colchicine may prevent cirrhosis in chronic hepatitis B patients with risk factor(s), possibly by suppressing exacerbations of hepatitis through an anti-inflammatory effect. 相似文献