首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   710459篇
  免费   50293篇
  国内免费   1321篇
耳鼻咽喉   9230篇
儿科学   23422篇
妇产科学   17784篇
基础医学   110905篇
口腔科学   20202篇
临床医学   63914篇
内科学   135647篇
皮肤病学   16344篇
神经病学   49614篇
特种医学   26060篇
外国民族医学   76篇
外科学   105911篇
综合类   14797篇
现状与发展   2篇
一般理论   160篇
预防医学   51257篇
眼科学   16400篇
药学   54458篇
  3篇
中国医学   2323篇
肿瘤学   43564篇
  2019年   5550篇
  2018年   7987篇
  2017年   6216篇
  2016年   6940篇
  2015年   7680篇
  2014年   10414篇
  2013年   15600篇
  2012年   20845篇
  2011年   21874篇
  2010年   12969篇
  2009年   12129篇
  2008年   20353篇
  2007年   21960篇
  2006年   22393篇
  2005年   20900篇
  2004年   20451篇
  2003年   19359篇
  2002年   18865篇
  2001年   36583篇
  2000年   37180篇
  1999年   30506篇
  1998年   7627篇
  1997年   6396篇
  1996年   6664篇
  1995年   6673篇
  1994年   6140篇
  1993年   5636篇
  1992年   23205篇
  1991年   23159篇
  1990年   22514篇
  1989年   22319篇
  1988年   20209篇
  1987年   19610篇
  1986年   18646篇
  1985年   17509篇
  1984年   12780篇
  1983年   10824篇
  1982年   5958篇
  1979年   11584篇
  1978年   8187篇
  1977年   6879篇
  1976年   6626篇
  1975年   7296篇
  1974年   8546篇
  1973年   8187篇
  1972年   7700篇
  1971年   7181篇
  1970年   6922篇
  1969年   6371篇
  1968年   5864篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
81.
In both adults and children with diabetes, technologies such as continuous subcutaneous insulin infusion using insulin pumps and continuous glucose monitoring can help improve diabetes control, reduce hypoglycaemia and improve quality of life. Access to these technologies in the UK is very variable. Some technologies are recommended by the National Institute for Health and Care Excellence, while others have not been appraised, and new technologies are emerging all the time. Additionally, different guidelines for adults and children further complicate access to diabetes technology in the transition from paediatric to adult care. Against this background, Diabetes UK and NHS England have brought together a multidisciplinary group of experts, including clinicians and people with diabetes, to develop this consensus guideline, combining the different technologies into a common pathway to aid clinical and policy decision‐making. We created a pathway that supports the incremental addition of technology as monotherapy and then dual therapy in the same way that we incrementally add in therapeutic agents to support people with Type 2 diabetes to achieve their personalized glycaemic targets. The pathway emphasizes the importance of structured education, specialist support and appropriate access to psychological therapies, as essential pillars for optimized use of diabetes‐related technology, and recommends the re‐evaluation of its use when the individual is unable either to use the technology appropriately or to achieve the intended outcomes. This pathway is endorsed by UK‐wide clinical and patient associations and we recommend that providers and commissioners use it to ensure the right individual with diabetes has access to the right technology in a timely way to help achieve better outcomes.  相似文献   
82.
83.
84.
85.

Objective

The aim of the study was to present the results for patients with atherosclerotic aneurysm of the descending thoracic aorta (DTA) treated with a novel thoracic stent graft.

Methods

A single-center retrospective review of prospectively collected data was performed. We extracted demographic variables as well as atherosclerotic comorbidities and operation-related and imaging-related data from patients' medical records. We estimated technical success rate, in-hospital and 30-day mortality, and mortality at the end of follow-up as well as complication and reintervention rate in our study cohort. Follow-up computed tomography angiography was performed after 1 month and 6 months and yearly thereafter.

Results

A total of 30 patients (80% male; mean age, 73.7 ± 6.33 years) were treated with Ankura Thoracic Stent Graft (Lifetech, Shenzhen, China) for DTA aneurysm from February 2014 until June 2017. Technical success of the thoracic endovascular aortic repair (TEVAR) was 97% (29/30 patients). A surgical conduit was required in one patient; in three patients, we intentionally covered the left subclavian artery because of insufficient proximal landing zone. No aorta-related deaths were recorded during follow-up. During the early postoperative period, two patients (7%) with long DTA coverage developed paralysis or paraparesis, which immediately resolved after lumbar drainage. No renal complications requiring dialysis were observed. One patient (3%) developed postoperative pulmonary infection, whereas access site complications were 7%. Two symptomatic patients treated outside instructions for use (7%) developed early type IA endoleak and one patient (3%) developed type IB endoleak; type II endoleak was recorded in 3% of the study cohort. During the 30-day postoperative period, two patients died of non-TEVAR-related causes, one of gastrointestinal bleeding and the other of pulmonary infection. During a median follow-up of 31.7 (range, 38.4) months, two more patients also died of non-TEVAR-related causes, one of stroke from carotid artery disease and the other of motor vehicle trauma. In the rest of the cohort, no other adverse events were noted.

Conclusions

This novel endograft showed early evidence of a safe, effective, and durable endoprosthesis for the treatment of DTA aneurysms.  相似文献   
86.

Background

Major depressive disorder (MDD) is a multifactorial disease which often coexists with cognitive deficits. Depression-induced cognitive deficits are known to be associated with aberrant reward processing, neurochemical and structural alterations. Recent studies have shown that chronic electrical stimulation of brain reward areas induces a robust antidepressant effect. However, the effects of repeated electrical self-stimulation of lateral hypothalamus - medial forebrain bundle (LH-MFB) on depression-induced cognitive deficits and associated neurochemical and structural alterations in the prefrontal cortex (PFC) are unknown.

Objectives

We investigated the effect of chronic rewarding self-stimulation of LH-MFB in neonatal clomipramine (CLI) model of depression. During adulthood, neonatal CLI and saline administered rats were implanted with bilateral electrodes stereotaxically in the LH-MFB and trained to receive intracranial self-stimulation (ICSS) for 14 days. The rats were tested for depressive-like behaviors, learning and memory followed by estimation of PFC volumes, levels of monoamines and its metabolites in the PFC.

Results

We found that chronic ICSS of LH-MFB reverses CLI-induced behavioral despair and anhedonia. Interestingly, self-stimulation normalizes the impaired novel object and location recognition memory in CLI rats. The amelioration of learning impairments in CLI rats was associated with the reversal of volume loss and restoration of monoamine metabolism in the PFC.

Conclusion

We demonstrated that repeated intracranial self-stimulation of LH-MFB ameliorates CLI-induced learning deficits, reverses altered monoamine metabolism and the atrophy of PFC. Our results support the hypothesis that chronic brain stimulation rewarding experience might be evolved as a potential treatment strategy for reversal of learning deficits in depression and associated disorders.  相似文献   
87.
88.
89.
90.

Introduction

Wilson's disease (WD) is a rare autosomal recessive disorder transmitted through a gene located on chromosome 13. Liver transplantation (LT) provides a therapeutic option for patients with WD presenting fulminant liver failure or drug resistance. LT in patients with WD has a twofold aim: to save the patient's life when the disorder has progressed to hepatic (or other organ) failure and to cure the underlying metabolic defect. The aim of our study was to investigate the indications, aspects and post-operative outcomes in pediatric patients (<?18 years old) with WD who underwent LT.

Methods

A meticulous search of the literature since 1971 was performed. A retrospective analysis of all the studies, presenting cases of LT in children due to WD, was conducted. Studies that did not report patients' characteristics, transplantation indications, post-operative outcomes, and complications, as well as those with small study populations (<?10 patients), were excluded.

Results

Six studies were included in the present review, which involved 290 children. The main indications for LT included chronic liver failure and fulminant liver failure. The average 1-year survival rate was 91.9%, while the average 5-year survival rate was 88.2%. Retransplantation was performed in 16 patients due to transplant rejection. In general, patients transplanted for WD displayed an excellent quality of life after LT.

Conclusion

LT is a safe and efficient procedure in selected pediatric patients with WD, demonstrating excellent long-term outcomes and quality of life.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号