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   27301篇
  免费   2806篇
  国内免费   183篇
耳鼻咽喉   324篇
儿科学   831篇
妇产科学   514篇
基础医学   3587篇
口腔科学   552篇
临床医学   3286篇
内科学   4815篇
皮肤病学   275篇
神经病学   2883篇
特种医学   1154篇
外科学   4233篇
综合类   689篇
一般理论   5篇
预防医学   2991篇
眼科学   534篇
药学   1774篇
  1篇
中国医学   12篇
肿瘤学   1830篇
  2021年   354篇
  2020年   218篇
  2019年   402篇
  2018年   498篇
  2017年   344篇
  2016年   348篇
  2015年   421篇
  2014年   586篇
  2013年   973篇
  2012年   1324篇
  2011年   1285篇
  2010年   715篇
  2009年   716篇
  2008年   1210篇
  2007年   1265篇
  2006年   1153篇
  2005年   1078篇
  2004年   1100篇
  2003年   1040篇
  2002年   909篇
  2001年   900篇
  2000年   931篇
  1999年   753篇
  1998年   390篇
  1997年   343篇
  1996年   358篇
  1995年   331篇
  1994年   282篇
  1993年   323篇
  1992年   644篇
  1991年   635篇
  1990年   601篇
  1989年   644篇
  1988年   589篇
  1987年   611篇
  1986年   537篇
  1985年   539篇
  1984年   410篇
  1983年   353篇
  1982年   260篇
  1981年   216篇
  1980年   212篇
  1979年   368篇
  1978年   204篇
  1977年   215篇
  1976年   250篇
  1975年   194篇
  1974年   240篇
  1973年   228篇
  1972年   187篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
As more patients survive cancer, and as more sophisticated multidrug antineoplastic protocols are developed, the chances of an anesthesiologist's coming into contact with patients who have been treated with such protocols are increasing. The anesthesiologist who must administer anesthesia to a patient who has had chemotherapy must be cognizant of the particular antineoplastic agents that have the potential for producing occult pulmonary dysfunction. Anesthetic management of these cases must be carefully planned and titrated to prevent further lung injury.  相似文献   
93.
Defining the minimum clinically important difference or delta to be detected in a clinical trial depends on a number of factors including the research hypothesis, patient characteristics, the nature of the intervention and the trial design. In 2 previous studies, we have developed standardized procedures for conducting outcome measurement based on current Food and Drug Administration and European League Against Rheumatism guidelines for clinical trials in ankylosing spondylitis, and thereafter, determined the standard deviation for these outcome measures. In the final component of this series of studies, we have employed a Delphi technique to establish estimates for delta, and calculated the sample size requirements under 2 different conditions of Type I and Type II error probabilities.  相似文献   
94.
Flaxseed supplementation and early markers of colon carcinogenesis.   总被引:5,自引:0,他引:5  
Since flaxseed ingestion produces potentially anticarcinogenic lignans in the colon, this study determined whether flaxseed decreases the risk for colon carcinogenesis. Following a single injection of azoxymethane (15 mg/kg body wt.), five groups of male Sprague-Dawley rats were fed a high-fat (20% corn oil) basal diet with or without supplementation with 5% or 10% flaxseed meal (FM) or flaxseed flour (FF) for four weeks. Upon sacrifice, colons were examined for aberrant morphology and cell proliferation. In the descending colon of supplemented groups, the total number of aberrant crypts and foci were significantly reduced by 41-53% and 48-57%, respectively. The labeling index (LI) was also 10-22% lower in these groups, except for the 5% FM group. While these effects are not linearly related to the level of flaxseed fed, it suggests that flaxseed feeding may reduce the risk for colon carcinogenesis.  相似文献   
95.
The incidence and contributing factors associated with post-casting peroneal nerve palsy were examined in a series of 110 consecutive pediatric femoral shaft fractures treated with early hip spica cast application. Four patients with peroneal nerve palsy were identified. All four had 90 degrees/90 degrees casts placed and underwent cast wedging for alignment. All palsies resolved with immediate cast removal. Other treatment options for certain femur fractures with significant initial shortening should be considered. We advise pre- and post-cast neurologic examination and avoidance of forceful distraction. Fracture manipulation, through wedging, should be delayed.  相似文献   
96.
97.
A new technique in the treatment of stress urinary incontinence utilizes a sling fashioned from a rectangular island of buried vaginal epithelium. We developed a model to study the natural history of vaginal wall covered by an epithelial flap in 12 rabbits sacrificed at intervals to 26 weeks. Histopathologic examination demonstrated an immediate acute inflammatory reaction. This early response was followed by formation of an epithelial lining of the potential space overlying the buried vaginal tissue. Acute inflammatory cells continued to enter this lumen until week 20, when granulomas were first detected. Histopathologic examination at twenty-six weeks showed stratified squamous epithelium lining the lumen. No deleterious inflammatory sequelae were detected, and no dysplastic or malignant changes were identified. These results suggest that buried vaginal epithelium is a safe (short term) tissue alternative for sling creation.  相似文献   
98.
The effect of a management protocol incorporating the selective use of fine catheter peritoneal cytology (FCPC) and laparoscopy on the unnecessary appendicectomy rate was studied in adult patients (≥16 years) treated at one district general hospital over an 11 -month period. Appendicectomy was performed on 62 adult patients managed according to this protocol, six (10%) of whom had a histologically normal appendix and no other acute condition requiring surgery. A further 57 patients underwent appendicectomy after standard clinical assessment and investigation without the use of FCPC or laparoscopy. Nineteen (33%) of these patients had a histologically normal appendix removed, with no other acute condition requiring surgical treatment. The selective use of FCPC and laparoscopy significantly reduced the unnecessary appendicectomy rate from 33% to 10% (χ2 = 10.0, P<0.005). The more widespread use of these techniques in patients with suspected appendicitis is therefore recommended.  相似文献   
99.
Anti-endotoxin therapy in primate bacteremia with HA-1A and BPI.   总被引:4,自引:1,他引:3  
OBJECTIVE: The in vivo neutralizing activities of an anti-lipopolysaccharide (LPS) antibody HA-1A (Centoxin [Centocor, Malvern, PA]), a human immunoglobulin M monoclonal antibody, and of bactericidal/permeability-increasing protein (BPI), an endogenously produced human LPS-neutralizing protein, were studied in a primate model of lethal Escherichia coli bacteremia. SUMMARY BACKGROUND DATA: HA-1A has been used with variable success against LPS activity in some animal models and in a recently reported clinical trial. However, no data assessing the efficacy of this agent in subhuman primates is available. Bactericidal/permeability-increasing protein is a product of polymorphomononuclear cells (PMNs) that is stored in azurophilic granules and exhibits LPS-neutralizing activity in vitro and in some in vivo models. METHODS: Immediately after E. coli infusion and in a blinded fashion, three baboons were treated with BPI (5 mg/kg bolus infusion and 95 micrograms/kg/min infusion over 4 hr). Three animals received 3 mg/kg BW of HA-1A, whereas another three baboons received a placebo treatment. RESULTS: The BPI-treated animals demonstrated significantly (p < 0.03) lower circulating LPS-limulus amoebocyte lysate (LAL) activity compared with the control animals, but this reduction in LPS-LAL activity was not associated with improved survival. HA-1A treatment did not reduce LPS-LAL activity. However, both BPI and HA-1A treatment did attenuate the pro-inflammatory cytokine response. CONCLUSION: The current data suggests that incomplete neutralization of endotoxin activity does not alter mortality from severe bacteremia. Given the diversity of mediator production under such circumstances, a strategy of combination therapy in the form of anti-lipopolysaccharide and anticytokine treatment may be necessary to achieve optimal survival.  相似文献   
100.
AIM: The aim of the study was to explore the information needs of informal carers, and how information from health professionals can become more effective for families caring for people with epilepsy. METHODS: A combined methodology was used, comprising an interview study and a survey. Twelve in-depth interviews with carers were carried out. The questionnaire was developed using the interview data, to which 70 carers responded. RESULTS: Four main themes have been drawn from the study. Carers' of people with epilepsy have a need for improved and more appropriate levels of information giving by health professionals in both primary and secondary care. Carers' perceived self-efficacy expectations in seeking information are positive but they do not always feel listened to. Carers' prefer to receive information in a one-to-one setting but also need information from formats other than leaflets. Carers' perceive barriers to having their information needs met, such as their needs being unrecognised in relation to the person with epilepsy.  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