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   1138篇
  免费   134篇
  国内免费   47篇
耳鼻咽喉   4篇
儿科学   58篇
妇产科学   24篇
基础医学   92篇
口腔科学   30篇
临床医学   159篇
内科学   194篇
皮肤病学   19篇
神经病学   43篇
特种医学   174篇
外科学   306篇
综合类   20篇
预防医学   58篇
眼科学   10篇
药学   94篇
肿瘤学   34篇
  2019年   7篇
  2018年   8篇
  2015年   18篇
  2014年   12篇
  2013年   23篇
  2012年   33篇
  2011年   25篇
  2010年   22篇
  2009年   18篇
  2008年   33篇
  2007年   59篇
  2006年   25篇
  2005年   36篇
  2004年   27篇
  2003年   26篇
  2002年   43篇
  2001年   24篇
  2000年   24篇
  1999年   29篇
  1998年   33篇
  1997年   35篇
  1996年   33篇
  1995年   32篇
  1994年   23篇
  1993年   28篇
  1992年   40篇
  1991年   29篇
  1990年   35篇
  1989年   46篇
  1988年   53篇
  1987年   46篇
  1986年   49篇
  1985年   35篇
  1984年   27篇
  1983年   26篇
  1982年   17篇
  1981年   16篇
  1980年   12篇
  1979年   25篇
  1978年   21篇
  1977年   26篇
  1976年   19篇
  1975年   14篇
  1974年   14篇
  1973年   10篇
  1971年   13篇
  1970年   8篇
  1969年   12篇
  1967年   7篇
  1966年   7篇
排序方式: 共有1319条查询结果,搜索用时 31 毫秒
1.
The cephalometric measurement known as Wits appraisal (AOBO) was studied to determine its importance in diagnosis, treatment, and prediction of treatment success. The Wits appraisal is used primarily to identify unreliable ANB values (those that do not accurately reflect the degree of horizontal jaw discrepancy, ie, those that differ greatly from the AOBO value). Therefore, differences between AOBO and ANB also were evaluated. Because neither measurement alone can assess jaw discrepancies with total accuracy, they were combined, plotted on a scattergram, and divided into equal zones to create a new index of horizontal skeletal discrepancies and treatment predictability. Pretreatment values correspond to treatment difficulty, and posttreatment values correspond to the effectiveness of treatment. Treatment time for each zone also was evaluated. We were able to draw several conclusions from this study. First, combining AOBO and ANB values results in a more accurate measurement of treatment difficulty. These combined values also can be used to predict both treatment time and the success of treatment for horizontal discrepancies. Second, the AOBO value predicts variations in treatment time at each ANB value. Finally, adding ANB and AOBO values and then dividing the total yields zones that represent statistically significant differences in treatment times and percentages of success. The zones also correlate with the difference between AOBO and ANB measurements.  相似文献   
2.
The effects of labeling a person as hypertensive have important implications for hypertension screening. The Hypertension Detection and Follow-up Program (HDFP) provides an opportunity to examine the effects of labeling, treatment, and study assignment on a large group of hypertensives (n = 10,070). Their answers to questions regarding perceived health and general well-being asked at baseline and again one year later were analyzed. There was no significant change in the perceived health status of persons who were unaware of their hypertension at baseline and remained untreated at one year (labeling alone). The effect of labeling plus treatment was associated with a significant decrease in perceived health. The effect of antihypertensive drug therapy on perceived health status was examined in persons who were aware of their hypertension but not on treatment at baseline, and on treatment at one year. The stepped care group (SC) had a significant improvement in their perceived health and a significant decrease in the amount of time spent worrying about their health. The referred care group (RC) had no change. Program assignment effects were studied in individuals aware of their hypertension and on treatment both at baseline and one year later. Both the SC and RC groups had a significant improvement in their perceptions of their health status. The SC group had a significant decrease in time spent worrying about their health, while the RC group showed no change. These reassuring results fail to support the suggestion that labeling persons as hypertensive is necessarily followed by negative psychological consequences.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
3.
4.
5.
6.
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.  相似文献   
7.
H C Polk 《Cancer》1986,57(3):411-415
Interest in cancer of the breast has begun to yield a concentrated sequence of specific information as to its basic nature, dietary influences, and its hormonal and genetic determinants. Clearly, the advent of improved early diagnosis has allowed the presentation to the clinician of a more favorable aspect of the tumor than has previously been seen, and has altered the overall clinical character of the disease. These advances open the possibilities of greatly expanded and enhanced treatment options, both for the informed physician and the inquiring patient. The rewards of early diagnosis include the possibilities of functional reconstruction, which may alter the potential patient attitude to such an extent that even earlier diagnosis will be achieved in years ahead. The complex issues of multimodality therapy and the honest and valid stratification of patients are the key issues in the further study of this challenging illness.  相似文献   
8.
报道了氯仿重结晶的棉酚的化学性质,样品在不同温度下干燥恒重后,经熔点、薄层层析、紫外光谱、红外光谱、X-射线衍射、热重量分析、元素(C,H,Cl)分析及棉酚合量测定等一系列的分析,确证了在60℃以下棉酚与氯仿成溶剂化物(solvate)。随着干燥温度的升高或在室温长时间的贮存,此现象逐渐消失,100℃真空干燥恒重后成为纯棉酚。  相似文献   
9.
Two hundred nine Duncan-Harley guinea pigs had intrathoracic inoculation with 10(8) Staphylococcus aureus, accompanied by blood and umbilical tape. One hundred fifty-two animals were excluded because of clinical recovery, early death, or complications related to intrathoracic polymethylmethacrylate (PMMA) bead placement. The remaining 57 animals had clinical signs of empyema thoracis and were the subjects of this study. Group I animals (N = 24) served as the controls and had no therapy. Group II animals (N = 14) were treated by intrathoracic placement of placebo PMMA beads. Group III animals (N = 19) were treated by intrathoracic placement of tobramycin sulfate-impregnated PMMA beads. There were no differences between the groups in pleural reaction or pneumonia scores. These findings demonstrate a similar host response to the established infection. Group III, however, had a higher sterilization rate than Groups I and II (p less than 0.05), a finding underlining the therapeutic effect of tobramycin-treated PMMA beads. We conclude that intrathoracic local antimicrobial therapy with slow-release tobramycin-impregnated PMMA beads may enhance empyema treatment by increasing the rate of local sterilization. More experiments are necessary to assess the efficacy of this potentially important therapeutic arm for the treatment of thoracic empyema.  相似文献   
10.
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