全文获取类型
收费全文 | 2327篇 |
免费 | 261篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 58篇 |
妇产科学 | 26篇 |
基础医学 | 273篇 |
口腔科学 | 94篇 |
临床医学 | 247篇 |
内科学 | 359篇 |
皮肤病学 | 43篇 |
神经病学 | 163篇 |
特种医学 | 144篇 |
外科学 | 386篇 |
综合类 | 111篇 |
预防医学 | 176篇 |
眼科学 | 17篇 |
药学 | 414篇 |
中国医学 | 1篇 |
肿瘤学 | 69篇 |
出版年
2021年 | 23篇 |
2019年 | 26篇 |
2018年 | 38篇 |
2017年 | 16篇 |
2016年 | 30篇 |
2015年 | 25篇 |
2014年 | 39篇 |
2013年 | 70篇 |
2012年 | 97篇 |
2011年 | 65篇 |
2010年 | 75篇 |
2009年 | 61篇 |
2008年 | 69篇 |
2007年 | 63篇 |
2006年 | 83篇 |
2005年 | 67篇 |
2004年 | 76篇 |
2003年 | 87篇 |
2002年 | 89篇 |
2001年 | 66篇 |
2000年 | 64篇 |
1999年 | 101篇 |
1998年 | 60篇 |
1997年 | 38篇 |
1996年 | 49篇 |
1995年 | 38篇 |
1994年 | 45篇 |
1993年 | 46篇 |
1992年 | 78篇 |
1991年 | 59篇 |
1990年 | 90篇 |
1989年 | 63篇 |
1988年 | 56篇 |
1987年 | 43篇 |
1986年 | 47篇 |
1985年 | 47篇 |
1984年 | 44篇 |
1983年 | 40篇 |
1982年 | 32篇 |
1981年 | 33篇 |
1980年 | 36篇 |
1979年 | 41篇 |
1978年 | 41篇 |
1977年 | 28篇 |
1976年 | 34篇 |
1975年 | 22篇 |
1974年 | 31篇 |
1973年 | 13篇 |
1972年 | 22篇 |
1967年 | 12篇 |
排序方式: 共有2597条查询结果,搜索用时 15 毫秒
1.
BARI NUHOLU ALI AYYILDIZ VECIHI FIDAN ÖZDEN CEBECI UUR KOAR CANKON GERMIYANOLU 《International journal of urology》2006,13(2):109-110
OBJECTIVE: Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In recent years, various studies have been published stating that children with nocturnal enuresis exhibit growth and skeletal maturation retardation. METHODS: In this cross-sectional study, we included 27 patients (16 boys, 11 girls) between the ages of 6 and 14 years who had presented with primary nocturnal enuresis (PNE) complaints. We included in the evaluation 19 healthy subjects (12 boys, 7 girls), who were the siblings of the children with PNE, as the control group. RESULTS: The patients in both groups were similar in chronological age, bone age, height and weight, with no significant difference between groups (P>0.05). CONCLUSION: The two groups in our study consisted of the same genetic background. Thus, our results were found to be different from the previous studies. We have concluded that there is no direct relationship between enuresis nocturnal and skeletal maturation. 相似文献
2.
3.
4.
5.
R M Sandford M J Bown R D Sayers J N London A R Naylor M J McCarthy 《European journal of vascular and endovascular surgery》2007,34(1):29-34
OBJECTIVES: Angioplasty is often used in the management of lower limb ischaemia and can reduce the need for infrainguinal bypass in some patients. There is an associated failure rate with this technique and bypass surgery is often used in this situation as a secondary limb salvage procedure. We aimed to evaluate the outcome of infrainguinal bypass grafting following failed attempt at angioplasty. METHODS: All cases of infrainguinal bypass at a single centre over a seven year period were identified and notes reviewed. Cases were divided into four groups according to their indication for surgery; acute ischaemia, chronic critical ischaemia, failed angioplasty and an 'other' group including aneurysmal disease and claudicants. The failed angioplasty group was compared with the other three groups. Survival analysis was performed using Kaplan Meier curves and groups compared in terms of long term patency and survival. RESULTS: Primary patency was 61.2% in the failed angioplasty group at 12 months compared with 60.6% in the other groups (P=1.11). There was also no significant difference in primary patency at 60 months (50% vs 40.6%, P=0.26). Survival at 12 months was also comparable between the groups (failed angioplasty group 74.2% compared with 77.3% in the other groups, P=0.662) as was 60 months survival (33.3% and 35.4% respectively, P=0.166). DISCUSSION: In this study, outcome of infrainguinal bypass following failed angioplasty was comparable to outcome of surgery performed for another indication. This paper supports the use of distal bypass surgery for limb salvage in cases where minimal access techniques have failed. 相似文献
6.
7.
The effects of glycine on the phasic changes in locomotor activity in the rat, caused by a persistent infusion of dopamine (DA) into the nucleus accumbens (ACB) were investigated. Dopamine (25 μg/24 hr), infused into the nucleus accumbens for 13 days, caused hyperactivity, with two peaks occurring on days 3–4 and 9–11. Glycine (12.5 or 25 μg/24 hr) infused into the nucleus accumbens on its own did not alter the locomotor activity, yet when infused at the same time as DA (25 μg/24 hr), glycine (12.5 or 25 μg/24 hr) inhibited the development of the first peak of hyperactivity induced by DA, with no effect on the second peak. A larger dose of glycine (50 μg/24 hr), infused alone, significantly increased locomotor activity, and a combination of this dose with DA (25 μg/24 hr), led to a temporal shift in the response to DA such that the first peak of hyperactivity was delayed to “fuse” with the second peak. The locomotor response to a threshold dose of DA (6.25 μg/24 hr) plus glycine (50 μg/24 hr) was no greater than could be accounted for by the hyperactivity response to glycine alone (50 μg/24 hr). Strychnine (10 μg/24 hr), infused into the nucleus accumbens, produced no alteration in locomotor activity. Similarly, when infused together with DA (25 μg/24 hr), strychnine (10 μg/24 hr) caused no significant alteration in the phasic hyperactivity induced by DA. However, strychnine (10 μg/24 hr), infused together with DA and glycine (25 and 12.5 μg/24 hr respectively), prevented the inhibition by glycine of the first peak of hyperactivity induced by DA. The results indicate that while glycine may not normally exert a tonic modulatory influence on those mechanisms in the nucleus accumbens which regulate locomotor activity, when applied exogenously glycine can partially moderate the locomotor response to DA, through an action on strychnine-sensitive receptors. 相似文献
8.
9.
10.
As EC validity criteria for the production of Daphnia magna neonates in standard toxicity tests set fecundity minima which must be attained, it is important that culture conditions provide an adequate ration of high quality food. Maintaining a steady supply of fresh algae can be problematical so the possibility of using frozen food was investigated. The performance of three generations of D. magna fed on diets of fresh or frozen Chlorella was compared. There were no significant effects on fecundity due to food type or generation. Cumulative fecundity (over 21 days) on fresh or frozen food exceeded 120 neonates per female and satisfied that EC validity criterion (60 neonates per female). In addition criteria relating to survival and variability were met. We conclude that frozen Chlorella are an acceptable substitute for fresh algae. 相似文献