全文获取类型
收费全文 | 53209篇 |
免费 | 3473篇 |
国内免费 | 2654篇 |
专业分类
耳鼻咽喉 | 304篇 |
儿科学 | 765篇 |
妇产科学 | 745篇 |
基础医学 | 9310篇 |
口腔科学 | 1098篇 |
临床医学 | 3404篇 |
内科学 | 7971篇 |
皮肤病学 | 679篇 |
神经病学 | 4927篇 |
特种医学 | 1318篇 |
外国民族医学 | 11篇 |
外科学 | 3705篇 |
综合类 | 8878篇 |
现状与发展 | 2篇 |
预防医学 | 2092篇 |
眼科学 | 508篇 |
药学 | 6910篇 |
5篇 | |
中国医学 | 1961篇 |
肿瘤学 | 4743篇 |
出版年
2023年 | 343篇 |
2022年 | 707篇 |
2021年 | 958篇 |
2020年 | 933篇 |
2019年 | 1353篇 |
2018年 | 1219篇 |
2017年 | 1294篇 |
2016年 | 1246篇 |
2015年 | 1414篇 |
2014年 | 2269篇 |
2013年 | 2722篇 |
2012年 | 2513篇 |
2011年 | 3040篇 |
2010年 | 2722篇 |
2009年 | 2695篇 |
2008年 | 3150篇 |
2007年 | 3244篇 |
2006年 | 3123篇 |
2005年 | 2927篇 |
2004年 | 2710篇 |
2003年 | 2473篇 |
2002年 | 1929篇 |
2001年 | 1745篇 |
2000年 | 1405篇 |
1999年 | 1287篇 |
1998年 | 1047篇 |
1997年 | 893篇 |
1996年 | 712篇 |
1995年 | 561篇 |
1994年 | 523篇 |
1993年 | 369篇 |
1992年 | 307篇 |
1991年 | 271篇 |
1990年 | 242篇 |
1989年 | 226篇 |
1988年 | 141篇 |
1986年 | 128篇 |
1985年 | 487篇 |
1984年 | 633篇 |
1983年 | 498篇 |
1982年 | 470篇 |
1981年 | 453篇 |
1980年 | 357篇 |
1979年 | 326篇 |
1978年 | 227篇 |
1977年 | 174篇 |
1976年 | 194篇 |
1975年 | 188篇 |
1974年 | 152篇 |
1973年 | 143篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
《Clinical neurophysiology》2021,132(9):2003-2011
ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons. 相似文献
3.
Jamie C. Capuzza 《Journal of Children and Media》2020,14(3):324-342
ABSTRACT This project examined 55 picture books featuring transgender, gender expansive or genderqueer protagonists or narrators published between 2008 and 2018. The purpose of the study was to determine how this genre of children’s literature supports and challenges four gender assumptions: the gender binary, gender essentialism, sex/gender congruency and gender stability. Additionally, this critical analysis explored misgendering within this genre and themes of social rejection and acceptance. Protagonists and narrators were permitted a degree of gender nonconformity, however, the majority of picture books missed opportunities for a more complete exploration of gender possibilities. 相似文献
4.
5.
6.
7.
8.
《Drug metabolism and pharmacokinetics》2020,35(1):56-70
Hepatic uptake mediated by organic anion transporting polypeptide (OATP) 1B1 and 1B3 can serve as a major elimination pathway for various anionic drugs and as a site of drug-drug interactions (DDIs). This article provides an overview of the in vitro approaches used to predict human hepatic clearance (CLh) and the risk of DDIs involving OATP1Bs. On the basis of the so-called extended clearance concept, in vitro–in vivo extrapolation methods using human hepatocytes as in vitro systems have been used to predict the CLh involving OATP1B-mediated hepatic uptake. CLh can be quantitatively predicted using human donor lots possessing adequate OATP1B activities. The contribution of OATP1Bs to hepatic uptake can be estimated by the relative activity factor, the relative expression factor, or selective inhibitor approaches, which offer generally consistent outcomes. In OATP1B1 inhibition assays, substantial substrate dependency was observed. The time-dependent inhibition of OATP1B1 was also noted and may be a mechanism underlying the in vitro–in vivo differences in the inhibition constant of cyclosporine A. Although it is still challenging to quantitatively predict CLh and DDIs involving OATP1Bs from only preclinical data, understanding the utility and limitation of the current in vitro methods will pave the way for better prediction. 相似文献
9.
10.