全文获取类型
收费全文 | 31814篇 |
免费 | 2668篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 285篇 |
儿科学 | 1173篇 |
妇产科学 | 962篇 |
基础医学 | 4121篇 |
口腔科学 | 443篇 |
临床医学 | 3968篇 |
内科学 | 5618篇 |
皮肤病学 | 599篇 |
神经病学 | 2973篇 |
特种医学 | 729篇 |
外国民族医学 | 1篇 |
外科学 | 4230篇 |
综合类 | 555篇 |
一般理论 | 48篇 |
预防医学 | 4101篇 |
眼科学 | 463篇 |
药学 | 2020篇 |
中国医学 | 28篇 |
肿瘤学 | 2245篇 |
出版年
2023年 | 335篇 |
2022年 | 387篇 |
2021年 | 1001篇 |
2020年 | 622篇 |
2019年 | 1013篇 |
2018年 | 1075篇 |
2017年 | 805篇 |
2016年 | 803篇 |
2015年 | 878篇 |
2014年 | 1222篇 |
2013年 | 1752篇 |
2012年 | 2579篇 |
2011年 | 2723篇 |
2010年 | 1444篇 |
2009年 | 1267篇 |
2008年 | 2013篇 |
2007年 | 2163篇 |
2006年 | 1960篇 |
2005年 | 1719篇 |
2004年 | 1548篇 |
2003年 | 1402篇 |
2002年 | 1270篇 |
2001年 | 337篇 |
2000年 | 269篇 |
1999年 | 280篇 |
1998年 | 266篇 |
1997年 | 189篇 |
1996年 | 147篇 |
1995年 | 153篇 |
1994年 | 131篇 |
1993年 | 92篇 |
1992年 | 207篇 |
1991年 | 195篇 |
1990年 | 178篇 |
1989年 | 141篇 |
1988年 | 151篇 |
1987年 | 127篇 |
1986年 | 153篇 |
1985年 | 133篇 |
1984年 | 110篇 |
1983年 | 96篇 |
1982年 | 75篇 |
1981年 | 61篇 |
1980年 | 55篇 |
1979年 | 95篇 |
1978年 | 80篇 |
1976年 | 55篇 |
1974年 | 65篇 |
1973年 | 78篇 |
1972年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses... 相似文献
2.
3.
Cameron Duff 《Addiction (Abingdon, England)》2020,115(7):1378-1381
In 1998 Howard Parker, Judith Aldridge & Fiona Measham published Illegal Leisure, a ground‐breaking study of profound changes in British youth cultures in the 1990s, and the place of drugs and drug use in these upheavals. This work introduced the ‘normalization thesis’ to the social sciences, offering a novel vocabulary for re‐imagining the normative character of young people's attitudes towards and experiences of illicit drug use. Arriving at the dawn of the new century, the book offered a thoroughgoing re‐thinking of the character of youth cultures at a time of great social, cultural, economic and technological disruption. In so doing, the book deftly anticipated many of the most interesting currents of critical drug studies that followed. 相似文献
4.
Mohid S Khan Thomas Walter Amy Buchanan-Hughes Emma Worthington Lucie Keeber Marion Feuilly Enrique Grande 《World journal of gastroenterology : WJG》2020,26(30):4537-4556
BACKGROUND Approximately 20% of patients with neuroendocrine tumours(NETs) develop carcinoid syndrome(CS),characterised by flushing and diarrhoea.Somatostatin analogues or telotristat can be used to control symptoms of CS through inhibition of serotonin secretion.Although CS is often the cause of diarrhoea among patients with gastroenteropancreatic NETs(GEP-NETs),other causes to consider include pancreatic enzyme insufficiency(PEI),bile acid malabsorption and small intestinal bacterial overgrowth.If other causes of diarrhoea unrelated to serotonin secretion are mistaken for CS diarrhoea,these treatments may be ineffective against the diarrhoea,risking detrimental effects to patient quality of life.AIM To identify and synthesise qualitative and quantitative evidence relating to the differential diagnosis of diarrhoea in patients with GEP-NETs.METHODS Electronic databases(MEDLINE,Embase and the Cochrane Library) were searched from inception to September 12,2018 using terms for NETs and diarrhoea.Congresses,systematic literature review bibliographies and included articles were also hand-searched.Any study designs and publication types were eligible for inclusion if relevant data on a cause(s) of diarrhoea in patients with GEP-NETs were reported.Studies were screened by two independent reviewers at abstract and full-text stages.Framework synthesis was adapted to synthesise quantitative and qualitative data.The definition of qualitative data was expanded to include all textual data in any section of relevant publications.RESULTS Forty-seven publications(44 studies) were included,comprising a variety of publication types,including observational studies,reviews,guidelines,case reports,interventional studies,and opinion pieces.Most reported on PEI on/after treatment with somatostatin analogs;9.5%-84% of patients with GEP-NETs had experienced steatorrhoea or confirmed PEI.Where reported,14.3%–50.7% of patients received pancreatic enzyme replacement therapy.Other causes of diarrhoea reported in patients with GEP-NETs included bile acid malabsorption(80%),small intestinal bacterial overgrowth(23.6%-62%),colitis(20%) and infection(7.1%).Diagnostic approaches included faecal elastase,breath tests,tauroselcholic(selenium-75) acid(Se HCAT) scan and stool culture,although evidence on the effectiveness or diagnostic accuracy of these approaches was limited.Assessment of patient history or diarrhoea characteristics was also reported as initial approaches for investigation.From the identified evidence,if diarrhoea is assumed to be CS diarrhoea,consequences include uncontrolled diarrhoea,malnutrition,and perceived ineffectiveness of CS treatment.Approaches for facilitating differential diagnosis of diarrhoea include improving patient and clinician awareness of non-CS causes and involvement of a multidisciplinary clinical team,including gastroenterologists.CONCLUSION Diarrhoea in GEP-NETs can be multifactorial with misdiagnosis leading to delayed patient recovery and inefficient resource use.This systematic literature review highlights gaps for further research on prevalence of non-CS diarrhoea and suitability of diagnostic approaches,to determine an effective algorithm for differential diagnosis of GEP-NET diarrhoea. 相似文献
5.
6.
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
7.
Anuj Shrestha Zeeshan Jawa Kathryn L. Koch Amy B. Rankin Qun Xiang Anand Padmanabhan Matthew S. Karafin Joshua J. Field 《Journal of clinical apheresis》2015,30(6):353-358
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
8.
9.
Shylo R. Johnson Dennis Slate Kathleen M. Nelson Amy J. Davis Samual A. Mills John T. Forbes Kurt C. VerCauteren Amy T. Gilbert Richard B. Chipman 《Viruses》2021,13(2)
Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA. 相似文献