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   1067篇
  免费   68篇
  国内免费   8篇
耳鼻咽喉   2篇
儿科学   32篇
妇产科学   33篇
基础医学   73篇
口腔科学   55篇
临床医学   121篇
内科学   293篇
皮肤病学   55篇
神经病学   69篇
特种医学   77篇
外科学   108篇
综合类   30篇
一般理论   3篇
预防医学   68篇
眼科学   6篇
药学   104篇
肿瘤学   14篇
  2019年   6篇
  2015年   12篇
  2014年   6篇
  2013年   28篇
  2012年   8篇
  2011年   10篇
  2010年   26篇
  2009年   23篇
  2008年   19篇
  2007年   14篇
  2005年   6篇
  2003年   6篇
  2002年   5篇
  2001年   9篇
  1999年   13篇
  1998年   28篇
  1997年   50篇
  1996年   59篇
  1995年   36篇
  1994年   37篇
  1993年   44篇
  1992年   17篇
  1991年   34篇
  1990年   23篇
  1989年   30篇
  1988年   27篇
  1987年   28篇
  1986年   21篇
  1985年   20篇
  1984年   13篇
  1983年   29篇
  1982年   24篇
  1981年   26篇
  1980年   15篇
  1979年   16篇
  1978年   11篇
  1977年   5篇
  1976年   8篇
  1975年   6篇
  1971年   13篇
  1970年   7篇
  1963年   13篇
  1959年   22篇
  1958年   39篇
  1957年   35篇
  1956年   40篇
  1955年   26篇
  1954年   26篇
  1949年   28篇
  1948年   21篇
排序方式: 共有1143条查询结果,搜索用时 31 毫秒
81.
目的:目前临床上常用低温冷冻法来保存同种异体肌腱,但操作较复杂费时,并且所保存的肌腱活性较低而限制其应用。采用已筛选的玻璃化法冷冻保存鸡屈趾深肌腱,并将复温后的玻璃化肌腱进行体外检测,探索其作为肌腱移植材料的可行性。方法:实验于2003-11/2005-02在解放军总医院骨科研究所完成。①实验材料及分组:来亨鸡16只,雄性,体质量2.5kg左右,随机分为2组,玻璃化组为玻璃化肌腱,新鲜肌腱组为新鲜肌腱,每组8只。②实验过程:切取来亨鸡屈趾深肌腱,置入玻璃化液内快速投入液氮保存2周制备玻璃化肌腱。③实验评估:将2组肌腱在体外进行大体、组织学及超微结构观察,羟脯氨酸含量测定,生物力学性能检测,并对两组肌腱进行细胞培养与鉴定。结果:①玻璃化组肌腱的大体、组织学及超微结构与新鲜肌腱组相似,其细胞及细胞外结构得以良好保存。②应用碱解法测定玻璃化肌腱内的羟脯氨酸含量为69.27mg/g,与新鲜肌腱组间差异无统计学意义。③玻璃化组肌腱破裂强度为165.58MPa,弹性模量1.41GPa,与新鲜肌腱组的力学性能差异无统计学意义。④将玻璃化组肌腱进行细胞培养,细胞第8天自组织块长出,第21天后传代,培养3代后出现明显的退化现象,其生物学特性与新鲜肌腱组相似。⑤将两组肌腱培养的细胞分别进行免疫组织化学染色,经鉴定均为肌腱细胞。结论:玻璃化法保存的肌腱具有良好的细胞活性、细胞外结构及力学性能,其生物学及生物力学特性无明显变异。  相似文献   
82.
In 1988, an optimal antiplatelet regimen for secondary stroke prevention remained to be defined. We undertook a randomised, placebo-controlled, double-blind trial to investigate the safety and efficacy of low-dose acetylsalicylic acid (ASA), modified-release dipyridamole, and the two agents in combination. Patients with prior stroke or transient ischaemic attack (TIA) were randomised to treatment with ASA alone (50 mg daily), modified-release dipyridamole alone (400 mg daily), the two agents in a combined formulation, or placebo. Primary endpoints were stroke, death, and stroke or death. TIA and other vascular events were secondary endpoints. Patients were followed on treatment for two years. We concluded that dipyridamole, in a modified-release form, at a dose of 200 mg b.d. and ASA 25 mg b.d., have been shown to be equally effective in the secondary prevention of ischaemic stroke and TIA; that when co-prescribed, the protective effects are additive, the combination being significantly more effective than each agent prescribed singly; and that low-dose ASA does not eliminate the propensity for induced bleeding.  相似文献   
83.
84.
We report the results of an external quality control program, including 17 Italian centers involved in the care of patients infected by HIV, to evaluate CD4 T cell count proficiency and reproducibility. The centers received two commercial stabilized blood preparations, one with "normal" and one with "low" CD4 T cell content. The centers were asked to process the samples two times, 1 week apart, with the same procedure used for samples from HIV patients. Most centers showed a good performance of CD4 frequency and absolute count determinations. In particular, the "low" sample was correctly analyzed by all centers; only two underestimated the "normal" sample CD4 frequency, and only one underestimated the CD4 absolute count by >100 CD4 cells/microl. Overall, our data suggest that most Italian laboratories provide reliable and reproducible results in evaluating CD4 T cells in HIV(+) samples.  相似文献   
85.
86.
87.
Aim  To determine the levels of anxiety and depression in young people with spinal cord injuries (SCI) and their associated factors and outcomes.
Method  Children and adolescents aged 7 to 17 years at interview who had sustained SCI at least 1 year before the study were assessed using the Children's Depression Inventory, the Revised Children's Manifest Anxiety Scale, the Pediatric Quality of Life Inventory, the Children's Assessment of Participation and Enjoyment, and a demographic questionnaire designed for the study.
Results  The 118 participants (61 males, 57 females) had a mean age of 12 years 4 months, SD 3y 1mo, range 7-17y. Mean age at injury was 5 years 11 months, SD 4y 11m, range 0-16y; 89 participants (75%) had paraplegia and 29 (25%) had tetraplegia. Fifty-seven (52%) had complete injuries and 52 (48%) had incomplete injuries according to the American Spinal Injury Association impairment scale. Thirteen participants (13%) reported significant symptoms of anxiety, and seven (6%) reported significant levels of depression, which were comparable to the normative population. Age, race, and sex were not associated with anxiety or depression, but participants with shorter duration of injury were more likely to be anxious, and those with less functional independence were more likely to be depressed. Only one dimension of participation was associated with anxiety and depression, but all aspects of quality of life were decreased among those with anxiety or depression.
Interpretation  The levels of anxiety and depression in young people with SCI are comparable to the normative range. When anxiety and depression occur they are associated with reduced levels of quality of life.  相似文献   
88.
Background  Adalimumab is a second generation humanized anti-tumour necrosis factor (TNF) monoclonal antibody with established efficacy in Crohn's disease (CD).
Aims  To evaluate the efficacy and safety of adalimumab on a nationwide clinical setting.
Methods  We used the Scottish Society of Gastroenterology network to identify and follow up the clinical outcomes of patients with CD treated with adalimumab over a 4-year period (2004–2008).
Results  A total of 98 patients received adalimumab - 100.5 patient follow-up years were recorded (64.3% females; median age at diagnosis of 20.7 years; 88.8% treated with 80/40 mg induction regimen. Eighty eight (89.8%) had previous infliximab with 29 (32.9%) primary nonresponders; 32 (32.6%) were corticosteroid-dependent; 47 (47.9%) were intolerant/resistant to most immunosuppressive therapies (two or more). In all, 60% of patients were in clinical remission at 1-year follow-up, with 30% and 55% requiring dose escalation to weekly therapy at 1-and 2-year follow-up respectively. Overall, 29 (29.6%) patients developed complications with eight nonfatal serious (8.2%) adverse events and 2 (2.0%) case fatalities (sepsis following perforation and disseminated colorectal cancer, respectively).
Conclusions  Adalimumab is efficacious in severe and refractory CD in the clinical setting, although there remain significant therapy- and disease-related risks of serious complications.  相似文献   
89.
90.
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