全文获取类型
收费全文 | 6019篇 |
免费 | 533篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 182篇 |
妇产科学 | 149篇 |
基础医学 | 759篇 |
口腔科学 | 196篇 |
临床医学 | 563篇 |
内科学 | 1127篇 |
皮肤病学 | 53篇 |
神经病学 | 375篇 |
特种医学 | 170篇 |
外国民族医学 | 14篇 |
外科学 | 810篇 |
综合类 | 105篇 |
一般理论 | 7篇 |
预防医学 | 1363篇 |
眼科学 | 49篇 |
药学 | 271篇 |
中国医学 | 2篇 |
肿瘤学 | 321篇 |
出版年
2021年 | 86篇 |
2020年 | 66篇 |
2019年 | 69篇 |
2018年 | 102篇 |
2017年 | 84篇 |
2016年 | 55篇 |
2015年 | 81篇 |
2014年 | 125篇 |
2013年 | 179篇 |
2012年 | 237篇 |
2011年 | 215篇 |
2010年 | 122篇 |
2009年 | 91篇 |
2008年 | 223篇 |
2007年 | 203篇 |
2006年 | 214篇 |
2005年 | 225篇 |
2004年 | 187篇 |
2003年 | 177篇 |
2002年 | 169篇 |
2001年 | 161篇 |
2000年 | 185篇 |
1999年 | 125篇 |
1998年 | 67篇 |
1996年 | 99篇 |
1995年 | 154篇 |
1994年 | 139篇 |
1993年 | 133篇 |
1992年 | 232篇 |
1991年 | 213篇 |
1990年 | 177篇 |
1989年 | 130篇 |
1988年 | 140篇 |
1987年 | 130篇 |
1986年 | 129篇 |
1985年 | 130篇 |
1984年 | 111篇 |
1983年 | 93篇 |
1982年 | 62篇 |
1981年 | 55篇 |
1979年 | 77篇 |
1978年 | 65篇 |
1976年 | 49篇 |
1974年 | 69篇 |
1973年 | 59篇 |
1972年 | 49篇 |
1971年 | 51篇 |
1970年 | 46篇 |
1969年 | 49篇 |
1968年 | 47篇 |
排序方式: 共有6558条查询结果,搜索用时 0 毫秒
21.
Pulsed ultrasonic Doppler velocimetry (20 MHz) (PUDVM) has evolved considerably in the last 10 years. Engineering development has resulted in a computer-controlled vessel-scanning instrument whose backscattered frequency shift spectra are analyzed using fast Fourier transforms (FFT). Benchtop and theoretic studies indicate accurate (error less than 5%) velocity and volumetric flow rate measurements in vessels with a lumen diameter as small as 1.2 mm. Clinical application of the PUDVM has provided transcutaneous measurements of blood flow variables in normal human digital arteries. Experimental application to arteries 1.0-1.5 mm has provided information on the hemodynamic effects of topical vasodilators, standard microarteriorrhaphy, variations in microvascular technique, interpositional grafts, and early wound repair. With improving computer capabilities and technical modifications, the PUDVM will be an increasingly important tool in clinical and experimental microsurgery. 相似文献
22.
Canadian Journal of Anesthesia/Journal canadien d'anesthésie - Today’s anaesthesia journals are faced with problems in the quality of materials being published. The stature of... 相似文献
23.
Lack of interaction between nefazodone and cimetidine: a steady state pharmacokinetic study in humans. 下载免费PDF全文
The steady-state pharmacokinetic interaction between nefazodone and cimetidine was evaluated in a three-period crossover study consisting of three treatments of 1 week duration with a 1 week washout between treatments. The 18 healthy, male study subjects received: nefazodone hydrochloride 200 mg twice daily (every 12 h) for 6 days; cimetidine 300 mg four times daily for 6 days; and 200 mg nefazodone hydrochloride twice daily + 300 mg cimetidine four times daily for 6 days. On day 7 of each treatment, only the morning dose was administered. Serial blood samples were collected for pharmacokinetic analysis after drug administration on day 7 of each treatment; blood samples for trough levels (Cmin) to assess attainment of steady state, were also collected just prior to the morning doses on days 2-7 of each study period. Plasma samples were assayed for cimetidine, and nefazodone and its metabolites hydroxynefazodone and m-chlorophenylpiperazine by specific, validated h.p.l.c. methods. Statistical analyses of Cmin data indicated that, regardless of treatment, steady state was achieved for cimetidine by day 2 and for nefazodone and its metabolites by day 3 of multiple dosing, and that there were no significant differences in Cmin levels between treatments. When nefazodone and cimetidine were co-administered for 1 week, no change in steady-state pharmacokinetic parameters for cimetidine, nefazodone or hydroxynefazodone was observed compared with each drug dosed alone.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
24.
25.
Conjugated linoleic acid (CLA) refers to a mixture of positional and geometric dienoic isomers of linoleic acid found naturally in animal products of ruminant sources. Recent interest in CLA research stems from the well-documented anticarcinogenic, antiatherogenic, antidiabetic, and antiobesity properties of CLA in rodents. However, there has been very little published human research on CLA. This review discusses the physiologic properties of CLA and their potential implications for human health. 相似文献
26.
Tetrabenazine (TBZ), a presynaptic dopamine depletor and postsynaptic dopamine receptor blocker, is widely used for the treatment of hyperkinetic movement disorders in adults. However, reports of its use in children are limited. We review the efficacy and tolerability of TBZ therapy in 31 children with hyperkinetic movement disorders refractory to other medications. TBZ was effective in reducing the severity of movement disorders resistant to treatment with other medicines. When compared to adult patients, pediatric patients required higher doses. Side effects were similar to the adult population; however, children had a lower incidence of drug-induced Parkinsonism. 相似文献
27.
N. M. Greene 《Anaesthesia》1994,49(10):930-930
28.
Sociometric status and academic, behavioral, and psychological adjustment: a five-year longitudinal study. 总被引:1,自引:0,他引:1
T H Ollendick M D Weist M C Borden R W Greene 《Journal of consulting and clinical psychology》1992,60(1):80-87
Six hundred fourth-graders rated how much they liked to play with each of their classmates and then nominated their three best friends; 296 of the 600 children were assigned sociometric classifications of popular, neglected, average, controversial, or rejected status (the remaining 304 children failed to meet inclusion criteria). Five years later, 267 of the 296 classified children (90.2%) were evaluated on measures of academic performance, social behavior, and psychological adjustment. The number and type of contacts with the juvenile justice system were also determined. In general, children classified as rejected or controversial tended to fare more poorly on indices of long-term adjustment than did children classified as popular, neglected, or average. Results are discussed in terms of the predictive validity of sociometric rating and nomination procedures and their utility in identifying children at risk for later maladjustment. 相似文献
29.
30.
Northern Ireland has one of the lowest breastfeeding initiation rates in the world. Given that attitudes toward infant feeding are formed at an early age and a high rate of teenage pregnancy, it has become necessary to survey attitudes to infant feeding and breastfeeding promotion preferences in teenagers in Northern Ireland. Questionnaires were distributed to teenagers aged 14 to 18 years (n = 419) based in 7 schools selected by type and location throughout Northern Ireland. Attitudes to breastfeeding in public reflected preferred infant-feeding method and were positively influenced by prior exposure to breastfeeding (P = .024). Females were more positive than males both in relation to breastfeeding in public (P = .002) and breastfeeding promotion (P = .003). Recommendations for breastfeeding promotion include specific targeting of young people (both male and female) and enabling contact between teenagers and nursing mothers as much as possible. 相似文献