全文获取类型
收费全文 | 8194篇 |
免费 | 858篇 |
国内免费 | 152篇 |
专业分类
耳鼻咽喉 | 117篇 |
儿科学 | 265篇 |
妇产科学 | 422篇 |
基础医学 | 1292篇 |
口腔科学 | 163篇 |
临床医学 | 1098篇 |
内科学 | 1373篇 |
皮肤病学 | 136篇 |
神经病学 | 674篇 |
特种医学 | 609篇 |
外科学 | 793篇 |
综合类 | 251篇 |
一般理论 | 11篇 |
预防医学 | 776篇 |
眼科学 | 160篇 |
药学 | 539篇 |
1篇 | |
中国医学 | 5篇 |
肿瘤学 | 519篇 |
出版年
2021年 | 93篇 |
2020年 | 78篇 |
2019年 | 89篇 |
2018年 | 127篇 |
2017年 | 74篇 |
2016年 | 126篇 |
2015年 | 100篇 |
2014年 | 155篇 |
2013年 | 250篇 |
2012年 | 329篇 |
2011年 | 391篇 |
2010年 | 213篇 |
2009年 | 207篇 |
2008年 | 342篇 |
2007年 | 387篇 |
2006年 | 319篇 |
2005年 | 338篇 |
2004年 | 329篇 |
2003年 | 277篇 |
2002年 | 286篇 |
2001年 | 282篇 |
2000年 | 285篇 |
1999年 | 242篇 |
1998年 | 171篇 |
1997年 | 147篇 |
1996年 | 149篇 |
1995年 | 158篇 |
1994年 | 137篇 |
1993年 | 128篇 |
1992年 | 198篇 |
1991年 | 178篇 |
1990年 | 198篇 |
1989年 | 228篇 |
1988年 | 196篇 |
1987年 | 175篇 |
1986年 | 148篇 |
1985年 | 134篇 |
1984年 | 135篇 |
1983年 | 92篇 |
1982年 | 88篇 |
1981年 | 66篇 |
1980年 | 77篇 |
1979年 | 122篇 |
1978年 | 92篇 |
1977年 | 78篇 |
1976年 | 95篇 |
1975年 | 69篇 |
1974年 | 81篇 |
1973年 | 59篇 |
1972年 | 67篇 |
排序方式: 共有9204条查询结果,搜索用时 15 毫秒
1.
Christopher D Hue Frances S Cho Siqi Cao Cameron R ”Dale” Bass David F Meaney Barclay Morrison III 《Journal of cerebral blood flow and metabolism》2015,35(7):1191-1198
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α− isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury. 相似文献
2.
Understanding the contribution of endothelial cells to the progenitor pools of adult tissues has the potential to inform therapies for human disease.To address whether endothelial cells transdifferentiate into non-vascular cell types,we performed cell lineage tracing analysis using transgenic mice engineered to express a fluorescent marker following activation by tamoxifen in vascular endothelial cadherin promoter-expressing cells(VEcad-CreERT2;B6 Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze).Activation of target-cell labeling following 1.5 months of ad libitum feeding with tamoxifen-laden chow in 4–5 month-old mice resulted in the tracing of central nervous system and peripheral cells that include:cerebellar granule neurons,ependymal cells,skeletal myocytes,pancreatic beta cells,pancreatic acinar cells,tubular cells in the renal cortex,duodenal crypt cells,ileal crypt cells,and hair follicle stem cells.As Nestin expression has been reported in a subset of endothelial cells,Nes-CreERT2 mice were also utilized in these conditions.The tracing of cells in adult Nes-CreERT2 mice revealed the labeling of canonical progeny cell types such as hippocampal and olfactory granule neurons as well as ependymal cells.Interestingly,Nestin tracing also labeled skeletal myocytes,ileal crypt cells,and sparsely marked cerebellar granule neurons.Our findings provide support for endothelial cells as active contributors to adult tissue progenitor pools.This information could be of particular significance for the intravenous delivery of therapeutics to downstream endothelial-derived cellular targets.The animal experiments were approved by the Boise State University Institute Animal Care and Use Committee(approval No.006-AC15-018)on October 31,2018. 相似文献
3.
4.
Annals of Surgical Oncology - 相似文献
5.
6.
7.
8.
9.
Anorectal function in the solitary rectal ulcer syndrome 总被引:8,自引:6,他引:2
Nigel R. Womack F.R.C.S. Professor Norman S. Williams M.S. John H. Holmfield Mist John F. Morrison Ph.d. 《Diseases of the colon and rectum》1987,30(5):319-323
The anorectal function of nine patients with solitary rectal ulcer syndrome (SRUS) (5 F: 4 M, median age, 27 (range, 19–41
years) and nine control subjects (5 F: 4 M, median age, 47 (35–66)P<0.01) has been investigated by a new technique that radiologically visualizes the anorectum during voiding of a semisolid
contrast medium, while simultaneously measuring intrarectal pressure and anal sphincter EMG activity. A degree of rectal prolapse
was demonstrated in eight of the SRUS patients; six of these lesions were clinically occult. Abnormal failure of the anal
sphincter to relax on voiding was present in seven of the SRUS patients. These abnormalities resulted in the SRUS patients
requiring a greater increase in intrarectal pressure (median, 100 cm water) to void than the control subjects (median, 65
cm water,P<0.01). This combination of high intrarectal pressure and rectal prolapse during straining seems to be the cause of SRUS
This work was supported by a grant from the Medical Research Council. 相似文献
10.
Scott A Fields Elizabeth Morrison Ernie Yoder Kevin Krane Thomas Agresta Rich Esham Frederick McCurdy Jonathan Rosen James Shumway 《Academic medicine》2002,77(6):543-546
PURPOSE: Chart notes are used to support billing codes under the evaluation and management guidelines of the Health Care Financing Administration (HCFA), in addition to serving as a record of the visit. To better understand the effect of the HCFA documentation guidelines, the authors collected data on how the guidelines affect participation by university- and community-based faculty in clinical education programs. METHOD: In 2000, the authors sent six copies of their questionnaire to the associate deans of the 125 U.S. medical schools and requested they distribute them to all core clerkship directors. The questionnaire consisted of multiple-choice and short-answer questions regarding documentation of medical visits, participation of community-based faculty, understanding of HCFA documentation guidelines, and effects on education programs. RESULTS: The response rate was about 50%. Most of the 379 clerkship directors who responded (77%) stated they were aware the HCFA documentation guidelines include specifications regarding the role medical students can play and documentation of medical visits, and 64% indicated they were concerned the guidelines would affect their educational programs. Concerns included the loss of student independence and active participation in the patient care environment (37), time constraints and the changing balance between education and service (16), loss of faculty and decreased morale (11), and decreased quality of care for patients (7). CONCLUSION: Leaders of medical education must work to modify these guidelines to protect the quality of patients' care, while maximizing students' educational opportunity and participation. 相似文献