全文获取类型
收费全文 | 2958篇 |
免费 | 235篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 98篇 |
妇产科学 | 15篇 |
基础医学 | 390篇 |
口腔科学 | 62篇 |
临床医学 | 318篇 |
内科学 | 606篇 |
皮肤病学 | 50篇 |
神经病学 | 294篇 |
特种医学 | 94篇 |
外科学 | 449篇 |
综合类 | 18篇 |
一般理论 | 5篇 |
预防医学 | 339篇 |
眼科学 | 41篇 |
药学 | 157篇 |
中国医学 | 4篇 |
肿瘤学 | 245篇 |
出版年
2024年 | 8篇 |
2023年 | 26篇 |
2022年 | 58篇 |
2021年 | 135篇 |
2020年 | 62篇 |
2019年 | 101篇 |
2018年 | 104篇 |
2017年 | 86篇 |
2016年 | 81篇 |
2015年 | 106篇 |
2014年 | 121篇 |
2013年 | 164篇 |
2012年 | 221篇 |
2011年 | 242篇 |
2010年 | 128篇 |
2009年 | 116篇 |
2008年 | 209篇 |
2007年 | 208篇 |
2006年 | 133篇 |
2005年 | 129篇 |
2004年 | 146篇 |
2003年 | 99篇 |
2002年 | 91篇 |
2001年 | 23篇 |
2000年 | 19篇 |
1999年 | 27篇 |
1998年 | 28篇 |
1997年 | 26篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 16篇 |
1991年 | 17篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1973年 | 7篇 |
1962年 | 6篇 |
排序方式: 共有3201条查询结果,搜索用时 15 毫秒
1.
Jenny U. Johansson Nathaniel S. Woodling Qian Wang Maharshi Panchal Xibin Liang Angel Trueba-Saiz Holden D. Brown Siddhita D. Mhatre Taylor Loui Katrin I. Andreasson 《The Journal of clinical investigation》2015,125(1):350-364
Microglia, the innate immune cells of the CNS, perform critical inflammatory and noninflammatory functions that maintain normal neural function. For example, microglia clear misfolded proteins, elaborate trophic factors, and regulate and terminate toxic inflammation. In Alzheimer’s disease (AD), however, beneficial microglial functions become impaired, accelerating synaptic and neuronal loss. Better understanding of the molecular mechanisms that contribute to microglial dysfunction is an important objective for identifying potential strategies to delay progression to AD. The inflammatory cyclooxygenase/prostaglandin E2 (COX/PGE2) pathway has been implicated in preclinical AD development, both in human epidemiology studies and in transgenic rodent models of AD. Here, we evaluated murine models that recapitulate microglial responses to Aβ peptides and determined that microglia-specific deletion of the gene encoding the PGE2 receptor EP2 restores microglial chemotaxis and Aβ clearance, suppresses toxic inflammation, increases cytoprotective insulin-like growth factor 1 (IGF1) signaling, and prevents synaptic injury and memory deficits. Our findings indicate that EP2 signaling suppresses beneficial microglia functions that falter during AD development and suggest that inhibition of the COX/PGE2/EP2 immune pathway has potential as a strategy to restore healthy microglial function and prevent progression to AD. 相似文献
2.
Anand Dayama Nikolaos Tsilimparis Stephen Kolakowski Nathaniel M. Matolo Misty D. Humphries 《Journal of vascular surgery》2019,69(1):156-163.e1
Background
Chronic limb-threatening ischemia (CLTI), defined as ischemic rest pain or tissue loss secondary to arterial insufficiency, is caused by multilevel arterial disease with frequent, severe infrageniculate disease. The rise in CLTI is in part the result of increasing worldwide prevalence of diabetes, renal insufficiency, and advanced aging of the population. The aim of this study was to compare a bypass-first with an endovascular-first revascularization strategy in patients with CLTI due to infrageniculate arterial disease.Methods
We reviewed the American College of Surgeons National Surgical Quality Improvement Program targeted lower extremity revascularization database from 2012 to 2015 to identify patients with CLTI and isolated infrageniculate arterial disease who underwent primary infrageniculate bypass or endovascular intervention. We excluded patients with a history of ipsilateral revascularization and proximal interventions. The end points were major adverse limb event (MALE), major adverse cardiovascular event (MACE), amputation at 30 days, reintervention, patency, and mortality. Multivariable logistic regression was used to determine the association of a bypass-first or an endovascular-first intervention with outcomes.Results
There were 1355 CLTI patients undergoing first-time revascularization to the infrageniculate arteries (821 endovascular-first revascularizations and 534 bypass-first revascularizations) identified. There was no significant difference in adjusted rate of 30-day MALE in the bypass-first vs endovascular-first revascularization cohort (9% vs 11.2%; odds ratio [OR], 0.73; 95% confidence interval [CI], 0.50-1.08). However, the incidence of transtibial or proximal amputation was lower in the bypass-first cohort (4.3% vs 7.4%; OR, 0.60; CI, 0.36-0.98). Patients with bypass-first revascularization had higher wound complication rates (9.7% vs 3.7%; OR, 2.75; CI, 1.71-4.42) compared with patients in the endovascular-first cohort. Compared with the endovascular-first cohort, the incidence of 30-day MACE was significantly higher in bypass-first patients (6.9% vs 2.6%; adjusted OR, 3.88; CI, 2.18-6.88), and 30-day mortality rates were 3.23% vs 1.8% (adjusted OR, 2.77; CI, 1.26-6.11). There was no difference in 30-day untreated loss of patency, reintervention of treated arterial segment, readmissions, and reoperations between the two cohorts. In subgroup analysis after exclusion of dialysis patients, there was also no significant difference in MALE or amputation between the bypass-first and endovascular-first cohorts.Conclusions
CLTI patients with isolated infrageniculate arterial disease treated by a bypass-first approach have a significantly lower 30-day amputation. However, this benefit was not observed when dialysis patients were excluded. The bypass-first cohort had a higher incidence of MACE compared with an endovascular-first strategy. These results reaffirm the need for randomized controlled trials, such as the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL-2) trial and Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI), to provide level 1 evidence for the role of endovascular-first vs bypass-first revascularization strategies in the treatment of this population of challenging patients. 相似文献3.
4.
5.
6.
Frequent and recurrent ventricular premature beats (VPB's) are considered to be associated with a higher risk of sudden cardiac death, particularly for survivors of myocardial infarction (MI). The distribution of VPB's has a large probability mass at zero, and a very heavy right hand tail. In this research, we fitted a model to VPB for patients for which VPB was present. The model was fitted on the basis of a relatively large data set on MI survivors in Israel. The model was fitted by a method which is based on the generalized linear model. This method, which was introduced by Zeger and Liang, is designed for longitudinal data and uses the quasi-likelihood concept. No specific assumptions are required on the shape of the distribution of the dependent variable. The results indicate that the model fits the data quite well but underestimates the very extreme high values. This research demonstrates the applicability of generalized linear models for longitudinal non-Gaussian data. Such data often arise in medical studies. The study also points out the distributional properties of VPB counts. In particular, it shows their associations with simple clinical and epidemiological variables, and with certain time periods during the day. 相似文献
7.
8.
9.
10.
Management of common bile duct stones 总被引:3,自引:0,他引:3
Eric S. Hungness M.D. Nathaniel J. Soper M.D. 《Journal of gastrointestinal surgery》2006,10(4):612-619
Conclusions Choledocholithiasis remains a complicated and challenging disease process for today’s clinicians. Transabdominal ultrasound
and ERC are the most common preoperative imaging modalities with endoscopic ultrasound, MRCP, and HCT emerging as potentially
more accurate and less invasive tools. Intraoperatively, LUS and IOC are complimentary in detecting CBD stones, while laparoscopic
CBDE is commonly and safely performed by surgeons comfortable with advanced laparoscopic techniques. Postoperative ERC is
effective with failure of laparoscopic CBDE, surgeon inexperience, and unfavorable anatomy and patient selection. Open CBDE
should never be looked upon as a failure, while sphincterotomy, sphincteroplasty, and choledochoenterostomy remain necessary
operations for certain patients. The proposed algorithm is only a guideline, and ultimate treatment depends on physician experience
and available resources. 相似文献