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   926437篇
  免费   67598篇
  国内免费   1335篇
耳鼻咽喉   12947篇
儿科学   24307篇
妇产科学   23229篇
基础医学   132122篇
口腔科学   28246篇
临床医学   80140篇
内科学   181952篇
皮肤病学   19225篇
神经病学   71837篇
特种医学   36767篇
外国民族医学   79篇
外科学   151744篇
综合类   18022篇
现状与发展   1篇
一般理论   234篇
预防医学   61346篇
眼科学   21256篇
药学   72390篇
  3篇
中国医学   2119篇
肿瘤学   57404篇
  2018年   8964篇
  2017年   7037篇
  2016年   7763篇
  2015年   8866篇
  2014年   11985篇
  2013年   17505篇
  2012年   24093篇
  2011年   25047篇
  2010年   14808篇
  2009年   14279篇
  2008年   24615篇
  2007年   25705篇
  2006年   26497篇
  2005年   25441篇
  2004年   24573篇
  2003年   23571篇
  2002年   23100篇
  2001年   54676篇
  2000年   56444篇
  1999年   46760篇
  1998年   10261篇
  1997年   8988篇
  1996年   9131篇
  1995年   8880篇
  1994年   8252篇
  1993年   7568篇
  1992年   35467篇
  1991年   33913篇
  1990年   32731篇
  1989年   31865篇
  1988年   28977篇
  1987年   28249篇
  1986年   26278篇
  1985年   25139篇
  1984年   17813篇
  1983年   15118篇
  1982年   7764篇
  1981年   6738篇
  1979年   15757篇
  1978年   10583篇
  1977年   9027篇
  1976年   7867篇
  1975年   8618篇
  1974年   10455篇
  1973年   9849篇
  1972年   9355篇
  1971年   8847篇
  1970年   8414篇
  1969年   7916篇
  1968年   7197篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
Fibroelastolytic papulosis is a rare, acquired fibroelastolytic disorder that presents clinically as white‐to‐yellow papules and plaques most commonly occurring on the neck of elderly patients. The term fibroelastolytic papulosis encompasses two closely related conditions previously described as pseudoxanthoma elasticum‐like papillary dermal elastolysis (PDE) and white fibrous papulosis of the neck (WFPN). Here we present a case of a 78‐year‐old white female with a several‐year history of numerous, asymptomatic 2–3 mm yellowish, non‐follicular papules distributed symmetrically over the posterior neck, axillae, arm and antecubital fossae. Histopathologic examination revealed thickened and clumped elastotic fibers admixed with thick, sclerotic appearing collagen bundles in the mid and deep reticular dermis. Rare melanophages, loss of vertically oriented elastic fibers and scattered elastotic globes were noted in the papillary dermis. Based on the shared clinicopathologic features showed in this case, strong consideration should be made for the additional inclusion of papillary dermal elastosis as existing along the disease continuum of fibroelastolytic papulosis. This occurrence of fibroelastolytic papulosis shows unique histopathologic findings of pseudoxanthoma elasticum‐like PDE, papillary dermal elastosis and WFPN, further supporting the theory that these entities exist as variants along the fibroelastolytic papulosis spectrum.  相似文献   
992.
993.
994.
995.

Background and purpose

Shoulder arthroplasty is being performed in the United States with increasing frequency. We describe the medium-term findings from a large integrated healthcare system shoulder arthroplasty registry.

Patients and methods

Shoulder arthroplasty cases registered between January 2005 and June 2013 were included for analysis. The registry included patient characteristics, surgical information, implant data, attrition, and patient outcomes such as surgical site infections, venous thromboembolism, and revision procedures.

Results

During the study period, 6,336 primary cases were registered. Median follow-up time for all primaries was 3.3 years; 461 cases were lost to follow-up by ending of health plan membership. Primary cases were predominantly female (56%) and white (81%), with an average age of 70 years. The most common reason for surgery was osteoarthritis in 60% of cases, followed by acute fracture (17%) and rotator cuff tear arthropathy (15%). In elective shoulder arthroplasty procedures, 200 all-cause revisions (4%) were reported, with glenoid wear being the most common reason.

Interpretation

Most arthroplasties were elective procedures: over half performed for osteoarthritis. Glenoid wear was the most common reason for revision of primary shoulder arthroplasty in elective cases.In the period 2000 through 2010, over 200,000 shoulder arthroplasties were performed in the USA for osteoarthritis (Trofa et al. 2014). With the increasing use of shoulder arthroplasty (SA) over the past decade (Kim et al. 2011) and projections that future growth rates of SA may exceed those of hip and knee arthroplasty (Day et al. 2010), the need to track the outcomes of SA is becoming increasingly important.Arthroplasty registries provide an important mechanism for tracking surgical outcomes. In the fields of total hip arthroplasty and total knee arthroplasty, registries have demonstrated their importance in monitoring revisions, complications, and mortality, identifying outlier prostheses, and improving quality of care (Graves et al. 2004, Herberts and Malchau 2000, de Steiger et al. 2013, Paxton et al. 2010). SA registries have also provided critical information about demographics, survival, and outlier implants, though there have been considerably fewer publications from the younger national SA registries than from the more established hip and knee registries (Clitherow et al. 2014, Young et al. 2013, Rasmussen et al. 2012a, Rasmussen et al. 2014a and b, Fevang et al. 2009, Fevang et al. 2013). The lack of a national US registry emphasizes the need to use existing US registries to conduct international comparisons of SA patients, implants, surgical techniques, and outcomes. We present the medium-term findings of a large integrated healthcare system SA registry.  相似文献   
996.

Introduction

Mobile phone technologies have been promoted to improve adherence to antiretroviral therapy (ART). We studied the receptiveness of patients in a rural Ugandan setting to the use of short messaging service (SMS) communication for such purposes.

Methods

We performed a cross-sectional analysis measuring mobile phone ownership and literacy amongst patients of The AIDS Support Organisation (TASO) in Jinja, Uganda. We performed bivariate and multivariate logistic regression analyses to examine associations between explanatory variables and a composite outcome of being literate and having a mobile phone.

Results

From June 2012 to August 2013, we enrolled 895 participants, of whom 684 (76%) were female. The median age was 44 years. A total of 576 (63%) were both literate and mobile phone users. Of these, 91% (527/ 576) responded favourably to the potential use of SMS for health communication, while only 38.9% (124/319) of others were favourable to the idea (p<0.001). A lower proportion of literate mobile phone users reported optimal adherence to ART (86.4% vs. 90.6%; p=0.007). Male participants (AOR=2.81; 95% CI 1.83–4.30), sub-optimal adherence (AOR=1.76; 95% CI 1.12–2.77), those with waged or salaried employment (AOR=2.35; 95% CI 1.23–4.49), crafts/trade work (AOR=2.38; 95% CI 1.11–5.12), or involved in petty trade (AOR=1.85; 95% CI 1.09–3.13) (in comparison to those with no income) were more likely to report mobile phone ownership and literacy.

Conclusions

In a rural Ugandan setting, we found that over 60% of patients could potentially benefit from a mobile phone-based ART adherence support. However, support for such an intervention was lower for other patients.  相似文献   
997.
For countries with OIE status, FMD free country where vaccination is not practised, vaccinate‐to‐live policies have a significant economic disincentive as the trade restriction waiting period is double that of vaccinate‐to‐die policies. The disposal of healthy vaccinated animals strictly for the purpose of regaining markets with debatable scientific justification is a global concern. The feasibility of aligning the waiting periods to facilitate vaccinate‐to‐live is explored. The first article of this two‐part review (Barnett et al., 2015) explored the qualities of higher potency Foot‐and‐Mouth Disease (FMD) vaccines, performance of differentiating infected from vaccinated animals (DIVA) diagnostic assays particularly in vaccinates and carriers, as well as aspects of current limitations of post‐outbreak surveillance. Here, the history behind the OIE waiting periods for FMD free status is reviewed as well as whether the risk of vaccinated animals and their subsequent products differ appreciably at 3 versus 6 months. It is concluded that alignment is feasible for vaccinate‐to‐live using higher potency FMD vaccines within the current OIE waiting period framework of 3 and 6 months blocks of time. These waiting periods reflect precedence, historical practicalities and considered expert opinion rather than a specific scientific rationale. The future lies in updated epidemiological and diagnostic technology to establish an acceptable level of statistical certainty for surveillance or target probability of freedom of FMDV (infection or circulation) not time restricted waiting periods. The OIE Terrestrial Code limits trade from a FMD free country where vaccination is not practiced to animal products and live non‐vaccinated animals. The risk of FMDV in products derived from higher potency vaccinated animals is appreciably less than for countries with infected FMD status or even from a FMD free country where vaccination is practised for which the Code has Articles with guidelines for safe trade with time restrictions of 3 months or less. All these presume that key requirements in the implementation of emergency vaccination including appropriate vaccine match, vaccine application, susceptible population coverage, etc. are addressed.  相似文献   
998.
We described the aetiological agents of outbreaks of bovine ephemeral fever (BEF) that occurred in 1985 and 2012 in Turkey, and identify mutations in the viruses from both outbreaks. Outbreaks have emerged periodically every 4–5 years in the same regions in Turkey. Because these regions are located in a subtropical climatic zone, good conditions for vector populations exist. The results of this study show that the BEFVs from outbreaks in Turkey vary significantly. Effective prevention will require a vaccine that contains BEFVs from different genetic clusters.  相似文献   
999.
1000.
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