全文获取类型
收费全文 | 656篇 |
免费 | 43篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 40篇 |
妇产科学 | 12篇 |
基础医学 | 91篇 |
口腔科学 | 29篇 |
临床医学 | 46篇 |
内科学 | 120篇 |
皮肤病学 | 16篇 |
神经病学 | 13篇 |
特种医学 | 146篇 |
外国民族医学 | 1篇 |
外科学 | 40篇 |
综合类 | 50篇 |
预防医学 | 36篇 |
眼科学 | 5篇 |
药学 | 21篇 |
中国医学 | 4篇 |
肿瘤学 | 32篇 |
出版年
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 14篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 32篇 |
2012年 | 25篇 |
2011年 | 19篇 |
2010年 | 43篇 |
2009年 | 45篇 |
2008年 | 24篇 |
2007年 | 21篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 34篇 |
1995年 | 35篇 |
1994年 | 23篇 |
1993年 | 20篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1968年 | 1篇 |
1955年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有703条查询结果,搜索用时 15 毫秒
1.
2.
E MOLKE JENSEN K. A. THIESSEN AA. CHRISTENSEN 《Acta anaesthesiologica Scandinavica》1986,30(2):109-110
The effect of 4 mg oral naloxone on preoperative gastric volume and pH of gastric aspirate was studied in a double-blind, randomized study. Twenty patients received 10 ml of naloxone (4 mg) mixed with 10 ml of orange juice, and 20 patients received 10 ml of isotonic saline mixed with 10 ml of orange juice, 2 h before surgery. Gastric content was obtained immediately after intubation of the trachea. No significant difference in gastric volume and pH of gastric aspirate was found between the two groups. It is concluded that naloxone does not affect gastric emptying and gastric acid secretion to a degree great enough to protect against aspiration of gastric contents into the lungs. 相似文献
3.
4.
5.
6.
7.
8.
Lipid peroxidation, erythrocyte superoxide-dismutase activity and trace metals in young male footballers 总被引:6,自引:0,他引:6
Metin G Atukeren P Alturfan AA Gulyasar T Kaya M Gumustas MK 《Yonsei medical journal》2003,44(6):979-986
Physical training is known to induce oxidative stress in individuals subjected to intense exercise. In this study, we investigated plasma malondialdehyde (MDA) levels and erythrocyte superoxide dismutase (SOD) activity of 25 young male footballers and a control group of similar age. Red blood cell (RBC) count, haemoglobin (Hb) and haematocrit (Hct) values, and copper (Cu) and zinc (Zn) levels were also examined. The maximal oxygen uptake (VO2max) of all subjects was determined in order to establish their functional capacity. The main finding of the present study was that plasma MDA levels, one of the most commonly used markers of lipid peroxidation, of this group of footballers aged under 21 decreased slightly when compared with those of the control group (p < 0.001). In contrast, erythrocyte SOD activity was higher in the footballer group than in the controls (p < 0.001). Footballers who are under regular training showed an improved antioxidant activity in comparison to sedentary controls. Plasma copper concentration, RBC count and Hb concentration of the footballer group were all significantly lower than those of the control group, (p < 0.001, p < 0.01, p < 0.01, respectively). Investigating the footballers' data with Spearman's correlation analyses, the correlation coefficients (r) between Zn/Cu ratio and SOD was positive (r=0.44; p < 0.05); and between VO2max and SOD (r=0.42; p < 0.05) were both positive. On the basis of statistical analysis, we suggest that regular exercise may be beneficial in cases of oxidative damage by reducing the amount of lipid peroxidation and increasing the activity of the antioxidant enzyme SOD. 相似文献
9.
10.
Smoking and female infertility: a systematic review and meta-analysis 总被引:11,自引:10,他引:11
The high prevalence of smoking among women in their reproductive years
continues to be a matter of concern. The negative effects of smoking on
general health are well known, but smoking may also affect fertility. The
objective of the present study was to perform a systematic review of the
literature to determine whether there is an association between smoking and
risk of infertility in women of reproductive age, and to assess the size of
this effect. In the 12 studies used for this meta- analysis, the overall
value of the odds ratio (OR) for risk of infertility in women smokers
versus non-smokers was 1.60 [95% confidence interval (CI) 1.34-1.91].
Studies of subfertile women undergoing in-vitro fertilization (IVF)
treatment also show a reduction in fecundity among women smokers. A
meta-analysis of nine studies found an OR of 0.66 (95% CI 0.49-0.88) for
pregnancies per number of IVF- treated cycles in smokers versus
non-smokers. Despite the potential limitations of meta-analyses of
observational studies, the evidence presented in this review is compelling
because of the consistency of effect across different study designs, sample
size and types of outcome. However, continued reassurance is needed that
the calculated overall effect is not in fact due to confounding variables.
相似文献