全文获取类型
收费全文 | 2345080篇 |
免费 | 171253篇 |
国内免费 | 5787篇 |
专业分类
耳鼻咽喉 | 32175篇 |
儿科学 | 77570篇 |
妇产科学 | 66868篇 |
基础医学 | 343614篇 |
口腔科学 | 65375篇 |
临床医学 | 215740篇 |
内科学 | 451972篇 |
皮肤病学 | 47878篇 |
神经病学 | 189523篇 |
特种医学 | 87805篇 |
外国民族医学 | 696篇 |
外科学 | 342158篇 |
综合类 | 51068篇 |
现状与发展 | 2篇 |
一般理论 | 729篇 |
预防医学 | 188475篇 |
眼科学 | 53209篇 |
药学 | 176004篇 |
7篇 | |
中国医学 | 5044篇 |
肿瘤学 | 126208篇 |
出版年
2018年 | 25210篇 |
2017年 | 18976篇 |
2016年 | 20979篇 |
2015年 | 24038篇 |
2014年 | 33182篇 |
2013年 | 51218篇 |
2012年 | 70252篇 |
2011年 | 74966篇 |
2010年 | 43946篇 |
2009年 | 40839篇 |
2008年 | 70259篇 |
2007年 | 74998篇 |
2006年 | 75798篇 |
2005年 | 73764篇 |
2004年 | 70581篇 |
2003年 | 67728篇 |
2002年 | 66186篇 |
2001年 | 103818篇 |
2000年 | 106503篇 |
1999年 | 90071篇 |
1998年 | 25963篇 |
1997年 | 23425篇 |
1996年 | 23362篇 |
1995年 | 22108篇 |
1994年 | 20842篇 |
1993年 | 19438篇 |
1992年 | 72426篇 |
1991年 | 71351篇 |
1990年 | 69692篇 |
1989年 | 67039篇 |
1988年 | 62268篇 |
1987年 | 60817篇 |
1986年 | 58137篇 |
1985年 | 55619篇 |
1984年 | 41779篇 |
1983年 | 35930篇 |
1982年 | 21685篇 |
1981年 | 19228篇 |
1979年 | 39017篇 |
1978年 | 27645篇 |
1977年 | 23316篇 |
1976年 | 22465篇 |
1975年 | 23854篇 |
1974年 | 28556篇 |
1973年 | 27843篇 |
1972年 | 26144篇 |
1971年 | 24262篇 |
1970年 | 22595篇 |
1969年 | 21276篇 |
1968年 | 20100篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Qian Zhang Larry D. Mesner Gina M. Calabrese Naomi Dirckx Zhu Li Angela Verardo Qian Yang Robert J. Tower Marie-Claude Faugere Charles R. Farber Thomas L. Clemens 《The Journal of clinical investigation》2021,131(7)
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass. 相似文献
3.
4.
5.
6.
Heather L. Brown 《Journal of emergency nursing》2021,47(2):321-325
The coronavirus 2019 pandemic has affected almost every aspect of health care delivery in the United States, and the emergency medicine system has been hit particularly hard while dealing with this public health crisis. In an unprecedented time in our history, medical systems and clinicians have been asked to be creative, flexible, and innovative, all while continuing to uphold the important standards in the US health care system. To continue providing quality services to patients during this extraordinary time, care providers, organizations, administrators, and insurers have needed to alter longstanding models and procedures to respond to the dynamics of a pandemic. The Emergency Medicine Treatment and Active Labor Act of 1986, or EMTALA, is 1 example of where these alterations have allowed health care facilities and clinicians to continue their work of caring for patients while protecting both the patients and the clinicians themselves from infectious exposures at the same time. 相似文献
7.
8.
9.
10.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献