全文获取类型
收费全文 | 1651篇 |
免费 | 74篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 48篇 |
妇产科学 | 27篇 |
基础医学 | 160篇 |
口腔科学 | 27篇 |
临床医学 | 165篇 |
内科学 | 242篇 |
皮肤病学 | 33篇 |
神经病学 | 91篇 |
特种医学 | 161篇 |
外科学 | 236篇 |
综合类 | 264篇 |
预防医学 | 125篇 |
眼科学 | 10篇 |
药学 | 67篇 |
肿瘤学 | 72篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 17篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 18篇 |
2015年 | 39篇 |
2014年 | 29篇 |
2013年 | 47篇 |
2012年 | 51篇 |
2011年 | 54篇 |
2010年 | 70篇 |
2009年 | 75篇 |
2008年 | 77篇 |
2007年 | 86篇 |
2006年 | 91篇 |
2005年 | 83篇 |
2004年 | 97篇 |
2003年 | 57篇 |
2002年 | 45篇 |
2001年 | 52篇 |
2000年 | 50篇 |
1999年 | 59篇 |
1998年 | 49篇 |
1997年 | 58篇 |
1996年 | 57篇 |
1995年 | 38篇 |
1994年 | 46篇 |
1993年 | 19篇 |
1992年 | 25篇 |
1991年 | 29篇 |
1990年 | 28篇 |
1989年 | 14篇 |
1988年 | 29篇 |
1987年 | 28篇 |
1986年 | 26篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 7篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1967年 | 4篇 |
排序方式: 共有1735条查询结果,搜索用时 0 毫秒
11.
12.
13.
14.
P Oksa H Koskinen J P Rinne A Zitting P Roto M S Huuskonen 《American journal of industrial medicine》1992,21(4):561-567
Exposure to mineral dust was studied among construction workers (N = 437) with the aid of a questionnaire and a chest X-ray examination of the lungs. The results of the questionnaire showed that 81% of the construction workers had been exposed to asbestos. Exposure had occurred in all of the occupational groups studied. Pleural plaques and/or lung fibrosis (ILO greater than or equal to 1/1) were found in 26% of the examined workers; the prevalence varied from 18 to 40% among the various occupational groups. Comparison with a representative sample of the Finnish male population from another investigation indicates that the frequency of lung fibrosis (ILO greater than or equal to 1/1) is at least two times higher among the examined construction workers than among the general population. It seems likely that exposure to asbestos dust can be considered an etiological factor for an appreciable number of the X-ray findings. 相似文献
15.
16.
M H Frick O Elo K Haapa O P Heinonen P Heinsalmi P Helo J K Huttunen P Kaitaniemi P Koskinen V Manninen 《The New England journal of medicine》1987,317(20):1237-1245
In a randomized, double-blind five-year trial, we tested the efficacy of simultaneously elevating serum levels of high-density lipoprotein (HDL) cholesterol and lowering levels of non-HDL cholesterol with gemfibrozil in reducing the risk of coronary heart disease in 4081 asymptomatic middle-aged men (40 to 55 years of age) with primary dyslipidemia (non-HDL cholesterol greater than or equal to 200 mg per deciliter [5.2 mmol per liter] in two consecutive pretreatment measurements). One group (2051 men) received 600 mg of gemfibrozil twice daily, and the other (2030 men) received placebo. Gemfibrozil caused a marked increase in HDL cholesterol and persistent reductions in serum levels of total, low-density lipoprotein (LDL), and non-HDL cholesterol and triglycerides. There were minimal changes in serum lipid levels in the placebo group. The cumulative rate of cardiac end points at five years was 27.3 per 1,000 in the gemfibrozil group and 41.4 per 1,000 in the placebo group--a reduction of 34.0 percent in the incidence of coronary heart disease (95 percent confidence interval, 8.2 to 52.6; P less than 0.02; two-tailed test). The decline in incidence in the gemfibrozil group became evident in the second year and continued throughout the study. There was no difference between the groups in the total death rate, nor did the treatment influence the cancer rates. The results are in accord with two previous trials with different pharmacologic agents and indicate that modification of lipoprotein levels with gemfibrozil reduces the incidence of coronary heart disease in men with dyslipidemia. 相似文献
17.
Mahadevaiah SK; Odorisio T; Elliott DJ; Rattigan A; Szot M; Laval SH; Washburn LL; McCarrey JR; Cattanach BM; Lovell-Badge R; Burgoyne PS 《Human molecular genetics》1998,7(4):715-727
An RNA-binding motif (RBM) gene family has been identified on the human Y
chromosome that maps to the same deletion interval as the 'azoospermia
factor' (AZF). We have identified the homologous gene family (Rbm) on the
mouse Y with a view to investigating the proposal that this gene family
plays a role in spermatogenesis. At least 25 and probably >50 copies of
Rbm are present on the mouse Y chromosome short arm located between Sry and
the centromere. As in the human, a role in spermatogenesis is indicated by
a germ cell-specific pattern of expression in the testis, but there are
distinct differences in the pattern of expression between the two species.
Mice carrying the deletion Yd1, that maps to the proximal Y short arm, are
female due to a position effect resulting in non-expression of Sry ;
sex-reversing such mice with an Sry transgene produces males with a high
incidence of abnormal sperm, making this the third deletion interval on the
mouse Y that affects some aspect of spermatogenesis. Most of the copies of
Rbm map to this deletion interval, and the Yd1males have markedly reduced
Rbm expression, suggesting that RBM deficiency may be responsible for, or
contribute to, the abnormal sperm development. In man, deletion of the
functional copies of RBM is associated with meiotic arrest rather than
sperm anomalies; however, the different effects of deletion are consistent
with the differences in expression between the two species.
相似文献
18.
19.
Markku Walamies Matti Koskinen Arto Uusitalo Kari Niemelä 《The International Journal of Cardiac Imaging》1994,10(2):123-129
Myocardial metabolism in exercise was determined by studying 21 syndromeX patients and 14 healthy volunteers with an aromatic fatty acid analogue IPPA and a gamma camera. We developed criteria for visual semiquantitative assessment of relative segmental radiotracer uptake and washout, and tested a new computer program for quantitative evaluation. One volunteer (7%) and 12 patients (57%) showed visually inhomogeneous uptake (p=0.006, 2-test) in SPECT polar tomograms after a maximal ergometry test. Images in none of the volunteers and seven patients (33%) gave the impression of a slowed regional washout (p=0.057). Only six patients (29%) had a normal radial polarogram. Patients with irregular coronary angiograms (showing slow flow or minor sclerosis) and those with chest pain during the IPPA exercise test had a very low frequency of normalcy, but this was not significant.Total washout was higher in patients than in the reference population, as the exercise to rest activity ratio was 1.36 SD 0.13 versus 1.25 SD 0.11 in computerized quantitation (p=0.015, t-test). Washout did not correlate with age, sex or exercise heart rate. Regarding computerized analysis of uptake and slow washout, the number of deviant segments was not significantly higher in patients than in reference population. Semiquantitative and quantitative analysis correlated in the assessment of uptake, but not in the assessment of washout. Possible reasons for the discrepancy are discussed.Conclusions of this study are not straightforward. SyndromeX was associated with inhomogeneous IPPA uptake, which is not at variance with the theory of microvascular dysfunction. On the other hand, the analysis of washout presumably implies higher fatty acid utilization in patients than in normal controls, which is not a characteristic phenomenon in myocardial ischemia. 相似文献
20.
To find out the efficacy of sucralfate in preventing gastrointestinal side effects of non-steroidal anti-inflammatory drugs (NSAIDs) a prospective, randomised single blind study was conducted from 1989 to 1992. Patients with osteoarthritis, rheumatoid arthritis and other long standing painful conditions, who were expected to receive NSAIDs for over three months, were recruited into the study. All medicines were discontinued for a period of 10–15 days prior to initial endoscopic assessment. NSAID therapy was started and the patients were randomised to receive either placebo (group A) or sucralfate (group B) in addition. Patient were reassessed clinically every week and an endoscopic examination was repeated after 6–8 weeks of follow-up. A total of 176 patients were studied in group A (n=91) and group B (n=85). At the end of 8 weeks gastrointestinal symptoms were present in 30.6% and 26.4% patients of group A and B respectively. Endoscopic assessment showed superficial lesions in 36.5% and 18.7% while endoscopic ulcer in 2.4% and 1.1% patients of groups A and B respectively. Thus in patients receiving chronic NSAID therapy, simultaneous administration of sucralfate reduces the incidence of superficial gastric lesions but has no significant effect on symptoms or ulcer formation.KEY WORDS: Gastropathy, Sucralfate, Nonsteroidal anti-inflammatory drugs 相似文献