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   1383篇
  免费   62篇
  国内免费   113篇
耳鼻咽喉   1篇
儿科学   86篇
妇产科学   19篇
基础医学   144篇
口腔科学   22篇
临床医学   168篇
内科学   359篇
皮肤病学   40篇
神经病学   34篇
特种医学   362篇
外国民族医学   1篇
外科学   55篇
综合类   41篇
预防医学   67篇
眼科学   12篇
药学   84篇
中国医学   1篇
肿瘤学   62篇
  2023年   4篇
  2022年   5篇
  2021年   7篇
  2020年   8篇
  2019年   11篇
  2018年   14篇
  2016年   19篇
  2015年   20篇
  2014年   18篇
  2013年   39篇
  2012年   15篇
  2011年   31篇
  2010年   44篇
  2009年   49篇
  2008年   24篇
  2007年   65篇
  2006年   30篇
  2005年   51篇
  2004年   19篇
  2003年   16篇
  2002年   18篇
  2001年   21篇
  2000年   25篇
  1999年   23篇
  1998年   92篇
  1997年   97篇
  1996年   105篇
  1995年   63篇
  1994年   61篇
  1993年   65篇
  1992年   17篇
  1991年   32篇
  1990年   25篇
  1989年   46篇
  1988年   36篇
  1987年   48篇
  1986年   27篇
  1985年   44篇
  1984年   20篇
  1983年   17篇
  1982年   26篇
  1981年   22篇
  1980年   30篇
  1979年   11篇
  1978年   12篇
  1977年   17篇
  1976年   28篇
  1975年   15篇
  1970年   4篇
  1968年   6篇
排序方式: 共有1558条查询结果,搜索用时 0 毫秒
101.

Background  

Breast cancer management has improved dramatically in the past three decades and as a result, a population of working age women is breast cancer survivor. Interventions for breast cancer survivors have shown improvements in quality of life and in physical and psychological states. In contrast, efforts aimed at stimulating re-employment and return-to-work interventions for breast cancer survivors have not kept pace. The objective of this review was to study the effects and characteristics of intervention studies on breast cancer survivors in which the outcome was return to work.  相似文献   
102.
103.
104.
105.
SUMMARY The efficacy and safety of the methylprednisolone prodrugs methylprednisolone suleptanate and methylprednisolone sodium succinate were evaluated in a multicentre, randomised, double-blind, double-dummy parallel study of 88 patients hospitalised with acute asthma. Each study drug was administered as a bolus intravenous injection of 40mg methylprednisolone equivalents every 6 hours for 48 hours. Methylprednisolone 32mg was administered orally 6 hours after the last dose. Pulmonary function, medical events, and clinical laboratory values were assessed at predefined intervals before and during the 72-hour study. The primary response measure of pulmonary function was per cent predicted forced expiratory volume in one second (FEV1) at 48 hours. Secondary response measures were peak expiratory flow rate (PEFR) and FEV1/forced vital capacity (FVC) ratio. Although both drugs demonstrated within-group mean changes from baseline (starting at 6 hours) that were statistically significant for each response, there were no statistically significant differences between the two groups. The mean percent predicted FEV1 at 48 hours and mean per cent change from baseline were 64% and 13% (p<0.0001) for the methylprednisolone suleptanate group and 67% and 17% (p<0.0001) for the methylprednisolone sodium succinate group, respectively. The mean PEFR and FEV1/FVC ratio at 48 hours were 5.77 l/s and 73% for the methylprednisolone suleptanate group and 5.78 l/s and 76% for the methylprednisolone sodium succinate group, respectively. There were no clinically or statistically significant between-group differences in any of the safety parameters. In this study, methylprednisolone suleptanate and methylprednisolone sodium succinate have been shown to be therapeutically equivalent in the treatment of patients hospitalized with acute asthma.  相似文献   
106.
目的:利用小鼠胫骨牵引成骨动物模型,在牵引成骨过程中局部给予携带了LacZ的腺病毒载体后观察其表达情况,以探讨基因治疗促进骨折愈合的可行性。方法:实验于2004-10/2006-01在中南大学湘雅三医院完成。①实验分组:取雄性8周龄CD-1小鼠20只,随机数字表法分为实验组和对照组,每组各10只。②实验方法:所有小鼠接受左胫骨中上段骨干横行截骨安置特制延长外固定架,胫骨牵引过程包括5d静止期,10d牵引期,牵引速率为0.1mm/次,2次/d,共0.2mm/d。牵引期第7天实验组牵引骨痂局部注射5μL携带了LacZ的腺病毒载体,对照组局部注入等量未含LacZ腺病毒液。③实验评估:注射后第3天麻醉后杀取动物,采集左胫骨标本,分别作组织学检查和组织化学分析。结果:纳入小鼠20只,均进入结果分析。在牵引第10天,牵引骨痂中纤维间区形成,两端的新生骨由骨折两端中心生长延伸。骨髓腔内外可见大量新生骨形成。X-Gal底物染色显示,在实验组新生骨组织内可见大量细胞呈阳性染色;而对照组未发现阳性染色细胞。结论:在牵引成骨过程中,骨痂局部注射携带LacZ的腺病毒,能成功转染局部的成纤维细胞及成骨细胞,并表达LacZ基因,为临床应用基因治疗促进骨牵引延长或骨折愈合提供可行性。  相似文献   
107.
目的:观察低血糖指数的膳食对2型糖尿病患者氧化应激状态的影响。方法:2004-10/11在上海市静安区二个社区卫生服务中心招募受试者,经医生明确诊断为2型糖尿病、病程超过6个月,体质量指数≥24kg/m2的老年糖尿病志愿者43名,受试者对试验知情同意。采用随机交叉试验随机分配至低血糖指数饮食组和高血糖指数饮食组,每种膳食分别连续使用4周,间隔洗脱期4周,比较试验前后患者超氧化物歧化酶、脂质过氧化产物丙二醛和谷胱甘肽过氧化物酶含量的变化。结果:受试者依从性好,除1人因试验期间发现肿瘤而退出试验,42名志愿者按设计要求完成试验。膳食干预后低血糖指数饮食组和高血糖指数饮食组的超氧化物歧化酶活力分别升高了15.68%和21.33%,丙二醛水平分别下降23.94%和21.55%,谷胱甘肽过氧化物酶活力分别升高了15.74%和17.09%;干预后低血糖指数饮食组丙二醛下降水平与高血糖指数饮食组比较差异有显著性意义(P<0.05),而超氧化物歧化酶和谷胱甘肽过氧化物酶活性两组间差异无显著性意义(P>0.05)。结论:在控制总能量的基础上给予平衡膳食能够改善其氧化应激水平,采用低血糖指数食物有助于氧化应激水平的改善。  相似文献   
108.
Application of biosafety principles in blood establishments   总被引:1,自引:0,他引:1  
In light of increasing public and employee concern over potential infectious hazards associated with blood and other body fluids, several government agencies (the Food and Drug Administration, the Centers for Disease Control, the Occupational Safety and Health Administration, the Environmental Protection Agency, the Health Care Financing Administration and the National Heart, Lung and Blood Institute) cosponsored a Biosafety Workshop in April 1988. The objective of the workshop was to identify appropriate biosafety practices and standard control procedures to protect workers involved in the collection, storage, and transportation of human blood donations with the least possible disruption of the nation's blood supply. Speakers focused on human immunodeficiency virus (HIV) and hepatitis B virus (HBV); however, the safety principles discussed were considered equally applicable to other known (e.g., non-A, non-B hepatitis and human T-lymphotropic virus type I (HTLV-1) blood-transmitted infections. The resulting consensus included the need for blood establishments to develop and apply thoughtful biosafety programs to address staff training, accident prevention, HBV vaccination, handling spills, managing contaminated waste and transporting blood specimens. There was lack of agreement, however, on the usefulness of gloves during the phlebotomy of healthy blood donors.  相似文献   
109.
Summary— The organisation of a phase I unit must take into account the safety, quality and scientific requirements of such studies. The clinical pharmacology unit demands a highly qualified staff, as well as intensive care equipment. The investigator, generally a clinical pharmacologist who coordinates the different tasks as a project leader, has often to initiate a fruitful collaboration with a specialised consultant staff in order to implement the studies.  相似文献   
110.
Summary— Recent clinical studies have reported a beneficial effect of fluoxetine, a serotonin reuptake inhibitor, in patients with severe refractory orthostatic hypotension. The present study was undertaken to investigate the effect of fluoxetine in orthostatic hypotension occurring during Parkinson's disease on both blood pressure values and number of clinical symptoms during orthostatic procedure evaluated using a validated clinical rating scale. In a pilot study performed in fourteen patients with idiopathic Parkinson's disease plus orthostatic hypotension, fluoxetine hydrochloride (20 mg orally daily during one month) significantly reduced the fall in systolic blood pressure [-33 ± 21 (SD) mmHg before fluoxetine vs -22 ± 19 mmHg after fluoxetine, P = 0.03] elicited by standing without modifying heart rate. The drug also significantly reduced the number of postural symptoms occurring during the orthostatic procedure [2.9 ± 1.5 (SD) before fluoxetine vs 1.2 ± 1.3 after fluoxetine, P = 0.006]. A similar pattern of response was obtained in an experimental model of neurogenic orthostatic hypotension obtained in chronically sino-aortic denervated dogs submitted to an 80° head-up tilt test procedure under chloralose anaesthesia. Fluoxetine did not change plasma noradrenaline levels. This pilot study suggests a slight but clinically significant effect of fluoxetine on both hemodynamic parameters and clinical symptoms in parkinsonian patients suffering from orthostatic hypotension.  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