全文获取类型
收费全文 | 1666922篇 |
免费 | 108742篇 |
国内免费 | 2889篇 |
专业分类
耳鼻咽喉 | 21757篇 |
儿科学 | 54512篇 |
妇产科学 | 44855篇 |
基础医学 | 232826篇 |
口腔科学 | 40898篇 |
临床医学 | 141872篇 |
内科学 | 327067篇 |
皮肤病学 | 30207篇 |
神经病学 | 136813篇 |
特种医学 | 67899篇 |
外国民族医学 | 379篇 |
外科学 | 260974篇 |
综合类 | 31470篇 |
现状与发展 | 2篇 |
一般理论 | 468篇 |
预防医学 | 125677篇 |
眼科学 | 36718篇 |
药学 | 121653篇 |
2篇 | |
中国医学 | 3410篇 |
肿瘤学 | 99094篇 |
出版年
2021年 | 12120篇 |
2019年 | 12529篇 |
2018年 | 38965篇 |
2017年 | 30323篇 |
2016年 | 34793篇 |
2015年 | 17619篇 |
2014年 | 24172篇 |
2013年 | 35222篇 |
2012年 | 55444篇 |
2011年 | 72432篇 |
2010年 | 48380篇 |
2009年 | 39805篇 |
2008年 | 69210篇 |
2007年 | 76099篇 |
2006年 | 53467篇 |
2005年 | 54730篇 |
2004年 | 54122篇 |
2003年 | 53402篇 |
2002年 | 50221篇 |
2001年 | 60285篇 |
2000年 | 61591篇 |
1999年 | 52763篇 |
1998年 | 16985篇 |
1997年 | 15119篇 |
1996年 | 14967篇 |
1995年 | 14085篇 |
1994年 | 13347篇 |
1993年 | 12380篇 |
1992年 | 42029篇 |
1991年 | 41360篇 |
1990年 | 40790篇 |
1989年 | 39559篇 |
1988年 | 36863篇 |
1987年 | 36068篇 |
1986年 | 34426篇 |
1985年 | 32893篇 |
1984年 | 24831篇 |
1983年 | 21620篇 |
1982年 | 13414篇 |
1979年 | 23160篇 |
1978年 | 16430篇 |
1977年 | 14172篇 |
1976年 | 13419篇 |
1975年 | 14497篇 |
1974年 | 17027篇 |
1973年 | 16337篇 |
1972年 | 15500篇 |
1971年 | 14393篇 |
1970年 | 13359篇 |
1969年 | 12860篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Michael E Egger Joanna M Ohlendorf Charles R Scoggins Kelly M McMasters Robert C G Martin II 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2015,17(9):839-845
BackgroundThe aim of this paper is to assess the current state of quality and outcomes measures being reported for hepatic resections in the recent literature.MethodsMedline and PubMed databases were searched for English language articles published between 1 January 2002 and 30 April 2013. Two examiners reviewed each article and relevant citations for appropriateness of inclusion, which excluded papers of liver donor hepatic resections, repeat hepatectomies or meta-analyses. Data were extracted and summarized by two examiners for analysis.ResultsFifty-five studies were identified with suitable reporting to assess peri-operative mortality in hepatic resections. In only 35% (19/55) of the studies was the follow-up time explicitly stated, and in 47% (26/55) of studies peri-operative mortality was limited to in-hospital or 30 days. The time period in which complications were captured was not explicitly stated in 19 out of 28 studies. The remaining studies only captured complications within 30 days of the index operation (8/28). There was a paucity of quality literature addressing truly patient-centred outcomes.ConclusionQuality outcomes after a hepatic resection are inconsistently reported in the literature. Quality outcome studies for a hepatectomy should report mortality and morbidity at a minimum of 90 days after surgery. 相似文献
92.
93.
Michael L. Goodman Miriam S. Mutambudzi Stanley Gitari Philip H. Keiser Sarah E. Seidel 《Vulnerable children and youth studies》2016,11(4):366-378
There are an estimated 56 million orphans and vulnerable children across sub-Saharan Africa. Communities typically care for orphan children through informal caring arrangements – either within or outside of kinship networks. Within Kenya, an estimated 250,000 children live on the streets. There is less research related to fostering attitudes of this special population than orphans and vulnerable children generally. Important research over the past decade has illuminated multiple ways in which children are made more vulnerable because of HIV, including parental death and street-migration from HIV-affected households. As HIV transitions from a terminal illness to a chronic, manageable one, research is also required to establish how parents living with HIV can be an asset to children. In this study, we assess whether mothers living with HIV were very willing to foster biologically-related children, and street-involved children, how these fostering attitudes differed from mothers not living with HIV, and whether differences in fostering attitudes by reported HIV status were mediated by social support, family functioning and general self-rated health. Approximately 40% of mothers living with HIV were very willing to provide long-term foster care to biologically-related or street-involved children. This was less than the percentage of mothers not living with HIV, who were very willing to foster biologically-related children (61%) or street-involved children (58%). Significant portions of these differences were explained by social support, family functioning and general self-rated health. Multi-sectoral approaches are suggested by these findings in order to improve the child-fostering capacity of mothers living with HIV. Improving social support, family functioning and general self-rated health among HIV-infected mothers may not only provide protective benefits for the mothers and their children, but also expand the community’s capacity to care for orphan and vulnerable children. 相似文献
94.
95.
96.
Enrique Luengo Izaskun Buendia Cristina Fernndez‐Mendívil Paula Trigo‐Alonso Pilar Negredo Patrycja Michalska Borja Hernndez‐García Cristina Snchez‐Ramos Juan A. Bernal Tsuneya Ikezu Rafael Len Manuela G. Lpez 《Journal of pineal research》2019,67(1)
Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTauP301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTauP301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD. 相似文献
97.
98.
99.
100.
The serrated pathway (SP) can be viewed as two parallel, but partially overlapping, arrays of colorectal precursor lesions, and their respective endpoint carcinomas, that are distinct from those of the conventional adenoma–carcinoma sequence (APC‐pathway). In this review we focus at the outset on the clinical impact, pathological features, molecular genetics and biological behaviours of the various SP cancers. Then we summarize the clinicopathological features, classification and molecular profiles of the two main precursor lesions that anchor the respective pathways: (i) sessile serrated adenoma/polyp (SSA/P), also called sessile serrated lesion (SSL), and (ii) traditional serrated adenoma (TSA). Activating mutations of the RAS–RAF–MAPK pathway initiate and sustain the lesions of the SP, and CpG island methylation of the promoter regions of tumour suppressor and DNA repair genes play the major role in their neoplastic progression. The SP includes microsatellite stable (MSS) carcinomas that are among the most biologically aggressive colorectal carcinomas (CRC), and also accounts for the great preponderance of sporadic hypermutated, mismatch repair (MMR)‐deficient or microsatellite instable (MSI) CRC. The identification, removal and appropriate classification of at‐risk SP precursors and surveillance of individuals who harbour these lesions present a challenge and opportunity for CRC prevention and mortality reduction. 相似文献