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   2813篇
  免费   159篇
  国内免费   30篇
耳鼻咽喉   4篇
儿科学   105篇
妇产科学   30篇
基础医学   534篇
口腔科学   79篇
临床医学   378篇
内科学   600篇
皮肤病学   116篇
神经病学   135篇
特种医学   283篇
外科学   223篇
综合类   56篇
预防医学   97篇
眼科学   35篇
药学   270篇
中国医学   1篇
肿瘤学   56篇
  2018年   30篇
  2016年   26篇
  2015年   34篇
  2014年   31篇
  2013年   96篇
  2012年   51篇
  2011年   37篇
  2010年   62篇
  2009年   45篇
  2008年   45篇
  2007年   78篇
  2006年   78篇
  2005年   57篇
  2004年   41篇
  2003年   47篇
  2002年   45篇
  2001年   52篇
  2000年   53篇
  1999年   61篇
  1998年   92篇
  1997年   107篇
  1996年   111篇
  1995年   76篇
  1994年   76篇
  1993年   84篇
  1992年   54篇
  1991年   46篇
  1990年   55篇
  1989年   85篇
  1988年   73篇
  1987年   65篇
  1986年   68篇
  1985年   53篇
  1984年   68篇
  1983年   35篇
  1982年   38篇
  1981年   42篇
  1980年   60篇
  1979年   29篇
  1978年   36篇
  1977年   40篇
  1976年   43篇
  1975年   37篇
  1970年   24篇
  1965年   50篇
  1964年   50篇
  1963年   47篇
  1962年   41篇
  1961年   40篇
  1960年   65篇
排序方式: 共有3002条查询结果,搜索用时 0 毫秒
71.
This is the second part of a two‐part piece on self‐adhesive resin cements; Part I was presented in the previous issue of the Journal. Here in Part II, the specific topics concerning self‐adhesive cements are clinical performance, post‐cementation sensitivity, and cementation of endodontic posts.  相似文献   
72.
Nodding Syndrome is a poorly understood neurologic disorder of unknown aetiology that affects children and adolescents in Africa. Recent studies have suggested that the head nods are due to atonic seizures and Nodding Syndrome may be classified as probably symptomatic generalised epilepsy. As part of the Ugandan Ministry of Health clinical management response, a multidisciplinary team developed a manual to guide the training of health workers with knowledge and skills to manage the patients. In the absence of a known cause, it was decided to offer symptomatic care. The objective is to relieve symptoms, offer primary and secondary prevention for disability and rehabilitation to improve function. Initial management focuses on the most urgent needs of the patient and the immediate family until ‘stability’ is achieved. The most important needs were considered as seizure control, management of behavioural and psychiatric difficulties, nursing care, nutritional and subsequently, physical and cognitive rehabilitation. This paper summarises the processes by which the proposed guidelines were developed and provides an outline of the specific treatments currently being provided for the patients.  相似文献   
73.

INTRODUCTION

No national recording systems for knife injuries exist in the UK. Understanding the true size and nature of the problem of knife injuries is the first stage in reducing the burden of this injury. The aim of this study was to survey every knife injury seen in a single inner city emergency department (ED) over a one-year period.

METHODS

A cross-sectional observational study was performed of all patients attending with a knife injury to the ED of a London major trauma centre in 2011. Demographic characteristics, patterns of injury, morbidity and mortality data were collected.

RESULTS

A total of 938 knife injuries were identified from 127,191 attendances (0.77% of all visits) with a case fatality rate of 0.53%. A quarter (24%) of the major trauma team’s caseload was for knife injuries. Overall, 44% of injuries were selfreported as assaults, 49% as accidents and 8% as deliberate self-harm. The highest age specific incident rate occurred in the 16–24 year age category (263/100,000). Multiple injuries were seen in 19% of cases, of which only 81% were recorded as assaults. The mean length of stay for those admitted to hospital was 3.04 days. Intrathoracic injury was seen in 26% of cases of chest trauma and 24% of abdominal injuries had a second additional chest injury.

CONCLUSIONS

Violent intentional injuries are a significant contributory factor to the workload of the major trauma team at this centre. This paper contributes to a more comprehensive understanding of the nature of these injuries seen in the ED.  相似文献   
74.
75.
This study compares changes in the pro-oxidant production and buffering capacity in young and aged skeletal muscle after exposure to chronic repetitive loading (RL). The dorsiflexors from one limb of young and aged rats were loaded 3 times/week for 4.5 weeks using 80 maximal stretch-shortening contractions per session. RL increased H2O2 in tibialis anterior muscles of young and aged rats and decreased the ratio of reduced/oxidized glutathione and lipid peroxidation in aged but not young adult animals. Glutathione peroxidase (GPx) activity decreased whereas catalase activity increased with RL in muscles from young and aged rats. RL increased CuZn superoxide disumutase (SOD) and Mn SOD protein concentration and CuZn SOD activity in muscles from young but not aged animals. There were no changes in protein content for GPx-1 and catalase or messenger RNA for any of the enzymes studied. These data show that aging reduces the adaptive capacity of muscles to buffer increased pro-oxidants imposed by chronic RL.  相似文献   
76.
The Gay Bowel Syndrome   总被引:4,自引:0,他引:4  
Our experience in the management of 260 male homosexuals with coloreetal problems is described. The increased incidence of amebiasis, shigellosis and hepatitis, specific and nonspecific protocolitides, venereal disease and anal warts, is emphasized. It is important to recognize homosexual patients and the conditions to which they are predisposed.  相似文献   
77.
The cytoskeleton in Chediak-Higashi syndrome fibroblasts   总被引:2,自引:0,他引:2  
The Chediak-Higashi syndrome (CHS) trait is expressed in cultured human skin fibroblasts as an abnormal perinuclear concentration of moderately enlarged lysosomes. The cytoskeleton of CHS fibroblasts appears intact. Microtubules are normal in number and morphology, as assessed by colchicine binding studies, antitubulin immunofluorescence, and electron microscopy. Deformability by shear force is unaltered and microfilaments are abundant. However, CHS lysosomes appear to interact abnormally with the cytoskeleton, since the perinculear aggregation partially disperses after depolymerization of cell microtubules with colchicine. These results suggest that CHS is associated with a defect of either the lysosomal membrane itself or of lysosomal membrane- microtubule interaction.  相似文献   
78.
We report the generation and statistical analysis of the CSD drug subset: a subset of the Cambridge Structural Database (CSD) consisting of every published small-molecule crystal structure containing an approved drug molecule. By making use of InChI matching, a CSD Python API workflow to link CSD entries to the online database Drugbank.ca has been produced. This has resulted in a subset of 8632 crystal structures, representing all published solid forms of 785 unique drug molecules. We hope that this new resource will lead to improvements in targeted cheminformatics and statistical model building in a pharmaceutical setting. In addition to this, as part of the Advanced Digital Design of Pharmaceutical Therapeutics collaboration between academia and industry, we have been given the unique opportunity to run comparative analysis on the internal crystal structure databases of AstraZeneca and Pfizer, alongside comparison to the CSD as a whole.  相似文献   
79.
OBJECTIVETo determine whether the benefits of dapagliflozin in patients with heart failure and reduced ejection fraction (HFrEF) and type 2 diabetes in the Dapagliflozin And Prevention of Adverse-Outcomes in Heart Failure trial (DAPA-HF) varied by background glucose-lowering therapy (GLT).RESEARCH DESIGN AND METHODSWe examined the effect of study treatment by the use or not of GLT and by GLT classes and combinations. The primary outcome was a composite of worsening heart failure (hospitalization or urgent visit requiring intravenous therapy) or cardiovascular death.RESULTSIn the 2,139 type 2 diabetes patients, the effect of dapagliflozin on the primary outcome was consistent by GLT use or no use (hazard ratio 0.72 [95% CI 0.58–0.88] vs. 0.86 [0.60–1.23]; interaction P = 0.39) and across GLT classes.CONCLUSIONSIn DAPA-HF, dapagliflozin improved outcomes irrespective of use or no use of GLT or by GLT type used in patients with type 2 diabetes and HFrEF.  相似文献   
80.
IntroductionWith the emergence of the COVID-19 pandemic, all elective surgery was temporarily suspended in the UK, allowing for diversion of resource to manage the anticipated surge of critically unwell patients. Continuing to deliver time-critical surgical care is important to avoid excess morbidity and mortality from pathologies unrelated to COVID-19. We describe the implementation and short-term surgical outcomes from a system to deliver time-critical elective surgical care to patients during the COVID-19 pandemic.Materials and methodsA protocol for the prioritisation and safe delivery of time-critical surgery at a COVID-19 ‘clean’ site was implemented at the Nuffield Health Exeter Hospital, an independent sector hospital in the southwest of England. Outcomes to 30 days postoperatively were recorded, including unplanned admissions after daycase surgery, readmissions and complications, as well as the incidence of perioperative COVID-19 infection in patients and staff.ResultsA total of 128 surgical procedures were performed during a 31-day period by a range of specialties including breast, plastics, urology, gynaecology, vascular and cardiology. There was one unplanned admission and and two readmissions. Six complications were identified, and all were Clavien-Dindo grade 1 or 2. All 128 patients had preoperative COVID-19 swabs, one of which was positive and the patient had their surgery delayed. Ten patients were tested for COVID-19 postoperatively, with none testing positive.ConclusionThis study has demonstrated the implementation of a safe system for delivery of time-critical elective surgical care at a COVID-19 clean site. Other healthcare providers may benefit from implementation of similar methodology as hospitals plan to restart elective surgery.  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