全文获取类型
收费全文 | 31276篇 |
免费 | 2416篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 347篇 |
儿科学 | 691篇 |
妇产科学 | 719篇 |
基础医学 | 4415篇 |
口腔科学 | 853篇 |
临床医学 | 3507篇 |
内科学 | 5990篇 |
皮肤病学 | 296篇 |
神经病学 | 3131篇 |
特种医学 | 1287篇 |
外国民族医学 | 2篇 |
外科学 | 3806篇 |
综合类 | 459篇 |
一般理论 | 27篇 |
预防医学 | 2666篇 |
眼科学 | 702篇 |
药学 | 2477篇 |
中国医学 | 24篇 |
肿瘤学 | 2385篇 |
出版年
2022年 | 181篇 |
2021年 | 475篇 |
2020年 | 286篇 |
2019年 | 432篇 |
2018年 | 480篇 |
2017年 | 437篇 |
2016年 | 478篇 |
2015年 | 592篇 |
2014年 | 847篇 |
2013年 | 1263篇 |
2012年 | 1890篇 |
2011年 | 2021篇 |
2010年 | 1195篇 |
2009年 | 1028篇 |
2008年 | 1942篇 |
2007年 | 1903篇 |
2006年 | 1914篇 |
2005年 | 1976篇 |
2004年 | 1858篇 |
2003年 | 1828篇 |
2002年 | 1702篇 |
2001年 | 538篇 |
2000年 | 468篇 |
1999年 | 561篇 |
1998年 | 456篇 |
1997年 | 356篇 |
1996年 | 331篇 |
1995年 | 311篇 |
1994年 | 263篇 |
1993年 | 230篇 |
1992年 | 310篇 |
1991年 | 323篇 |
1990年 | 303篇 |
1989年 | 285篇 |
1988年 | 273篇 |
1987年 | 273篇 |
1986年 | 262篇 |
1985年 | 298篇 |
1984年 | 259篇 |
1983年 | 250篇 |
1982年 | 252篇 |
1981年 | 219篇 |
1980年 | 241篇 |
1979年 | 186篇 |
1978年 | 176篇 |
1977年 | 164篇 |
1976年 | 129篇 |
1975年 | 144篇 |
1974年 | 127篇 |
1973年 | 126篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Nidogen 1 (NID1) is a glycoprotein found in basement membranes involved in cross-linking collagen IV and laminin. The role of NID in breast cancer has only been evaluated in a small number of studies and the findings of these studies have been inconsistent. Our previous work revealed that highly tumorigenic murine mammary tumor cells express high levels of Nid1 while weakly tumorigenic mammary tumor cells express low levels of Nid1. To investigate Nid1, two stable knockdown lines were created, and Nid1 knockdown was confirmed at both the mRNA and protein level. Nid1 knockdown significantly reduced cell proliferation and migration/invasion and these reductions in proliferation and migration/invasion could be rescued by conditioned media containing NID1 protein. The reduced migration/invasion observed in the Nid1 knockdown cells was not associated with significant alterations in the epithelial gene Cdh1 or the mesenchymal genes Snai1, Snai2, Twist1, Twist2, Zeb1 and Zeb2. Therefore, suppression of Nid1 expression reduces proliferation and migration/invasion in claudin-low murine mammary tumor cells. 相似文献
2.
3.
4.
5.
ObjectivesTo fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area.ConclusionsMoving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns. 相似文献
6.
7.
Struan H. Coleman 《Arthroscopy》2019,35(4):1109-1110
Dancers have a disproportionately high prevalence of hip issues compared with other types of athletes. Many of these hip issues are complex: a cam and/or pincer impingement combined with a seemingly paradoxical borderline dysplasia, capsular laxity, and subsequent instability. Our experience as nonarthritic hip surgeons tells us that careful patient selection is critical for a successful outcome after the arthroscopic treatment of a dancer. But, there is little guidance in the literature on the management of this specific group of patients. We have studies that advise us to repair the labrum when possible versus performing labral debridement in female patients with predominantly pincer-type impingement and studies that support capsular plication and careful capsule closure in patients, predominantly female patients, with combined hip impingement and dysplasia or borderline dysplasia. However, few studies have examined predictors of outcomes after hip arthroscopy in dancers. 相似文献
8.
ABSTRACTScreening rates for trauma are low in health care settings. We examined the association between health care providers’ (HCPs) experience of physical or sexual trauma and their screening of female patients for trauma. HCPs at an urban academic medical institution were surveyed from September through November 2016. The Brief Trauma (BTQ) and Sexual and Physical Abuse History Questionnaires (SPAHQ) assessed their own experiences of trauma. The Screening Practices Questionnaire (SPQ) assessed HCPs trauma screening. Multiple regression analyses were performed. Among 212 respondents aged 22–67 years, most were female (78.3%) and white (76.1%). Nurses (41.0%) were the largest occupational group. Overall, 85.8% reported having experienced trauma. No significant difference was observed in median SPQ scores between HCPs who had experienced trauma (3.88 [Interquartile Range (IQR) 3.44–4.31]) and those who had not (4.00 [IQR 3.47–4.33], p = .645). In an adjusted model, screening policy awareness and having an obstetrics & gynecology or psychiatry specialty were associated with higher SPQ scores (p < .001). The prevalence of trauma experience in this sample was high, but not associated with screening. Screening policy awareness and practice specialty were associated with screening. HCP factors associated with greater trauma screening should be explored. 相似文献
9.
Anne-Marie Selzler Veronica Moore Razanne Habash Lauren Ellerton Erica Lenton Roger Goldstein 《COPD》2020,17(4):452-461
Abstract The purpose of this study was to investigate the strength of the relationships between self-efficacy and (i) functional exercise capacity and (ii) physical activity in chronic obstructive pulmonary disease (COPD), and whether self-efficacy assessment type (i.e., COPD symptoms, exercise-task, exercise-barrier, general, falls) and physical activity assessment type (i.e., self-report vs. objective) are moderators. A systematic search of COPD and self-efficacy concepts was conducted using eight databases from inception to 23 January 2019. Studies were included if they provided correlation coefficients of the relationship between self-efficacy and functional exercise capacity or physical activity, were conducted in adults diagnosed with COPD, and were published in English-language journals. A total of 14 correlation coefficients were included in the self-efficacy and functional exercise capacity meta-analysis, and 16 in the self-efficacy and physical activity meta-analysis. Data were screened, reviewed, and extracted independently by two reviewers, with discrepancies resolved by a third reviewer. Stronger self-efficacy was associated with better functional exercise capacity (weighted r?=?0.38, 95%CI [0.25, 0.50]), and greater physical activity (weighted r?=?0.25, 95%CI [0.17, 0.34]). Exercise-task self-efficacy had the strongest relationship to functional exercise capacity (weighted r?=?0.64, 95% CI [0.51, 0.73]). For physical activity, the type of self-efficacy most strongly related was inconclusive. In COPD, self-efficacy has a relationship to functional exercise capacity and physical activity, the strength of which is influenced by the choice of self-efficacy measure. An understanding of these relationships will assist clinicians in selecting the self-efficacy measure most closely related to the outcome of interest. 相似文献
10.
Facundo Davaro Jacob Roberts Allison May Coleman McFerrin Sameer Siddiqui Zachary Hamilton 《Journal of robotic surgery》2020,14(3):447-454
Partial nephrectomy is the mainstay of treatment for localized kidney cancer. A proportion of patients are upstaged post-operatively to locally advanced di 相似文献