Early renal transplant dysfunction can be caused by acute rejection,acute tubular necrosis (ATN), infection, ciclosporin toxicity,bleeding, urethral obstruction, urinary leak, lymphocele andthrombosis [1]. Prompt treatment of early allograft dysfunctionis essential and therefore accurate diagnosis mandatory. Wedescribe a patient with an unusual cause of allograft dysfunction,which was resolved by a simple surgical intervention.   A 32-year-old man with congenital blindness, hypertension andend-stage renal disease underwent renal transplantation. Hehad been haemodialysis-dependant since the age of 24 years.Dialysis was performed through an  相似文献   
56.
57.
58.
59.
Prospective study of short stature and newly diagnosed asthma in women.     
Deborah P Jones  Carlos A Camargo  Frank E Speizer  R Graham Barr 《The Journal of asthma》2007,44(4):291-295
The authors tested the hypothesis that short stature predicts adult-onset asthma independent of obesity among women in the Nurses' Health Study. Height, weight, and physician-diagnosed asthma were assessed with validated questionnaire items. Proportional hazard models adjusted separately for weight and body mass index. The rate of newly diagnosed asthma was 1.55 times greater in the shortest versus the tallest quintile after adjustment for weight (95% CI, 1.26-1.91). After adjustment for body mass index, the rate ratio was 1.16 (95% CI, 0.94-1.42). Short stature predicted adult-onset asthma in a large cohort of women, but this association was not independent of obesity.  相似文献   
60.
[首页] « 上一页 [1] [2] [3] [4] [5] 6 [7] [8] [9] [10] [11] 下一页 » 末  页»
  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   48964篇
  免费   3314篇
  国内免费   189篇
耳鼻咽喉   524篇
儿科学   1233篇
妇产科学   866篇
基础医学   6415篇
口腔科学   1255篇
临床医学   4763篇
内科学   9980篇
皮肤病学   727篇
神经病学   4839篇
特种医学   2553篇
外国民族医学   6篇
外科学   7245篇
综合类   595篇
一般理论   40篇
预防医学   4008篇
眼科学   1197篇
药学   2935篇
中国医学   69篇
肿瘤学   3217篇
  2023年   183篇
  2022年   287篇
  2021年   810篇
  2020年   614篇
  2019年   810篇
  2018年   955篇
  2017年   775篇
  2016年   918篇
  2015年   1053篇
  2014年   1472篇
  2013年   2053篇
  2012年   3119篇
  2011年   3291篇
  2010年   1873篇
  2009年   1713篇
  2008年   3062篇
  2007年   3154篇
  2006年   3115篇
  2005年   3045篇
  2004年   2854篇
  2003年   2766篇
  2002年   2660篇
  2001年   621篇
  2000年   571篇
  1999年   639篇
  1998年   606篇
  1997年   473篇
  1996年   429篇
  1995年   408篇
  1994年   326篇
  1993年   300篇
  1992年   374篇
  1991年   346篇
  1990年   313篇
  1989年   336篇
  1988年   300篇
  1987年   314篇
  1986年   287篇
  1985年   305篇
  1984年   311篇
  1983年   293篇
  1982年   320篇
  1981年   298篇
  1980年   266篇
  1979年   228篇
  1978年   234篇
  1977年   196篇
  1976年   169篇
  1975年   178篇
  1974年   184篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
51.
PURPOSE: Two experiments explored the extent to which induced blur, reduced luminance, and reduced visual fields affect drivers' steering performance in a driving simulator. METHODS: In experiment 1, ten young participants (M = 21.2 years) drove at approximately 89 km/h (55 mph) along a curvy roadway while being exposed to blur (0 to + 10 D), luminance (0.003 to 16.7 cd/m), and visual field (1.7 and 150 degrees) manipulations. In experiment 2, a new group of ten young participants (M = 18.5 years) drove while exposed to seven visual field sizes (1.7 to 150 degrees). RESULTS: Steering was sensitive to a reduced field size but not to the blur and luminance challenges. Acuity, on the other hand, was sensitive to the blur and luminance challenges but not to reduced field size. DISCUSSION: In healthy young drivers, steering performance is remarkably robust to severe blur and to extremely low luminances. These results support a key element of the selective degradation hypothesis advanced by Leibowitz and colleagues--that steering abilities are preserved at night even when the ability to recognize objects and hazards is not. Additional research should address the other element of this hypothesis--that drivers fail to appreciate the extent to which their visual abilities are degraded at night.  相似文献   
52.
The atypical antipsychotic risperidone is often prescribed to pediatric patients with neuropsychiatric disorders, though its effects on the developing brain remain unclear. Accordingly, we studied the effects of repeated treatment of risperidone on dopamine receptors in brain regions of juvenile rat. Levels of dopamine receptors (D(1), D(2), D(3), D(4)) in forebrain regions of juvenile rats were quantified after 3 weeks of treatment with three different doses of risperidone (0.3, 1.0 and 3.0 mg/kg) and compared findings to those in adult rats treated with risperidone (3.0 mg/kg/day) previously. Risperidone (at 1.0 and 3.0 mg/kg/day) increased levels of D(1) receptors in nucleus accumbens and caudate-putamen of juvenile, but not adult rats. Conversely, all three doses of risperidone dose-dependently increased D(2) labeling in medial prefrontal cortex and hippocampus, and D(4) receptor in nucleus accumbens, caudate-putamen and hippocampus of juvenile animals as well as in adults. Only the high dose of risperidone (3.0 mg/kg) increased D(2) receptors in caudate-putamen in both juvenile and adult brain. D(3) receptors were not altered by risperidone in any brain region at any dose or age. The findings indicate dose-dependent effects of risperidone on dopamine receptors in developing animals, and that juvenile animals are more sensitive than adults to the cerebral effects of risperidone.  相似文献   
53.
PURPOSE: To evaluate qualitative wall motion assessment vs. quantitative wall thickening for the assessment of subtle changes in myocardial systolic function using cine MRI. METHODS: Cine MR images were obtained in 5 canines with a significant coronary artery stenosis and in 2 controls on a 1.5T scanner. Qualitative results were obtained using a numerical scoring system; quantitative analysis was performed using a semi-automatic segmentation program. The techniques were matched and compared using Spearman correlations. RESULTS: All correlations in the experimental group revealed significant but weak to moderate relationships between the qualitative and quantitative results (e.g., at-risk tissue rho = 0.363, p < 0.0001; remote tissue rho = 0.275, p = 0.0002), with each identifying changes in regional function that ensued following creation of the stenosis. Intra-observer variability was reasonable in both methods when repeat analysis on a subset of the data was performed, with both techniques showing a significant correlation between the repeated measurements (quantitative - rho = 0.52, p < 0.0001; qualitative - rho = 0.54, p < 0.0001). CONCLUSION: Both methods were able to detect very limited wall motion abnormalities present in the canines with significant stenosis and either method gives comparable results.  相似文献   
54.
PURPOSE: Educational interventions to reduce the use of abbreviations and dosage designations that were deemed unsafe at a level 1 trauma center are described. SUMMARY: Strategies to reduce the use of unsafe abbreviations at Detroit Receiving Hospital were studied. Six abbreviations and dosage designations were deemed as unsafe by the site's medication-use and patient medical safety committees: (1) U for units, (2) microg for microgram, (3) TIW for three times a week, (4) the degree symbol for hour, (5) trailing zeros after a decimal point, and (6) the lack of leading zeros before a decimal point. Data on abbreviation use was collected starting in September 2003 by examining copies of patients' order sheets, which are sent from nursing units to the pharmacy for processing. Data were collected during three 24-hour periods each month, with 7-10 days between each period. A data collection sheet was developed to assist in documenting the number of opportunities for each unsafe abbreviation and the actual incidence of each. Educational strategies were developed and implemented starting in October 2003 to decrease the use of the unsafe abbreviations. These strategies included inservice education programs for the medical, pharmacy, and nursing staffs; laminated pocket cards; patient chart dividers; stickers; and interventions by pharmacists and nurses during medication prescribing. During the eight-month evaluation period, 20,160 orders were reviewed, representing 27,663 opportunities to use a designated unsafe abbreviation. Educational interventions successfully reduced the overall incidence of unsafe abbreviations from 19.69% to 3.31%. CONCLUSION: Educational interventions markedly reduced the use of unsafe abbreviations in medication orders over an eight-month evaluation period.  相似文献   
55.
   Introduction    Case report
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