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   2503篇
  免费   185篇
  国内免费   3篇
耳鼻咽喉   52篇
儿科学   118篇
妇产科学   86篇
基础医学   288篇
口腔科学   23篇
临床医学   313篇
内科学   510篇
皮肤病学   50篇
神经病学   182篇
特种医学   30篇
外科学   263篇
综合类   28篇
一般理论   1篇
预防医学   285篇
眼科学   54篇
药学   136篇
中国医学   9篇
肿瘤学   263篇
  2023年   10篇
  2022年   8篇
  2021年   52篇
  2020年   19篇
  2019年   41篇
  2018年   46篇
  2017年   39篇
  2016年   36篇
  2015年   54篇
  2014年   69篇
  2013年   120篇
  2012年   167篇
  2011年   163篇
  2010年   96篇
  2009年   94篇
  2008年   158篇
  2007年   178篇
  2006年   187篇
  2005年   184篇
  2004年   156篇
  2003年   144篇
  2002年   139篇
  2001年   54篇
  2000年   46篇
  1999年   42篇
  1998年   36篇
  1997年   18篇
  1996年   22篇
  1995年   16篇
  1994年   21篇
  1993年   22篇
  1992年   22篇
  1991年   26篇
  1990年   21篇
  1989年   15篇
  1988年   29篇
  1987年   21篇
  1986年   14篇
  1985年   8篇
  1984年   8篇
  1983年   8篇
  1982年   8篇
  1981年   11篇
  1978年   8篇
  1977年   9篇
  1975年   5篇
  1973年   6篇
  1971年   3篇
  1969年   4篇
  1965年   7篇
排序方式: 共有2691条查询结果,搜索用时 15 毫秒
1.

Background

Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.

Methods

A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.

Results

The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).

Conclusion

Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.

Level of Evidence

Therapeutic Level IV.  相似文献   
2.
In this study we consider the process of the clinical encounter, and present exemplars of how assumptions of both clinicians and their patients can shift or transform in the course of a diagnostic interview. We examine the process as it is recalled, and further elaborated, in post-diagnostic interviews as part of a collaborative inquiry during reflections with clinicians and patients in the northeastern United States. Rather than treating assumptions by patients and providers as a fixed attribute of an individual, we treat them as occurring between people within a particular social context, the diagnostic interview. We explore the diagnostic interview as a landscape in which assumptions occur (and can shift), navigate the features of this landscape, and suggest that our examination can best be achieved by the systematic comparison of views of the multiple actors in an experience-near manner. We describe what might be gained by this shift in assumptions and how it can make visible what is at stake for clinician and patient in their local moral worlds—for patients, acknowledgment of social suffering, for clinicians how assumptions are a barrier to engagement with minority patients. It is crucial for clinicians to develop this capacity for reflection when navigating the interactions with patients from different cultures, to recognize and transform assumptions, to notice ‘surprises’, and to elicit what really matters to patients in their care.  相似文献   
3.
4.
Background. Medication adherence impacts healthcare utilization. Pharmacy records are useful to establish fill patterns. Objective. Use pharmacy records to establish medication patterns fill patterns for comparison to healthcare utilization. Methods. Pharmacy records of 175 children with persistent asthma were collected and compared to healthcare utilization. Results. Majority of subjects had significant healthcare utilization, low numbers of rescue medications, and poor controller medication fill rates. Those with more rescue medications had more healthcare utilization and more controller medications. Conclusions. Pharmacy fill patterns demonstrate few rescue and/or controller medication fills. Those with more rescue medications reported increased healthcare utilization despite controller medications.  相似文献   
5.
The mortality profile of female nurses and teachers in British Columbia (BC) was examined using age-standardized proportional mortality ratios (PMRs) calculated for the period 1950–1984. Lowered overall mortality among nurses was seen for degenerative heart disease and for cerebrovascular accidents. Significantly elevated PMR values were observed for cancer of the breast and ovary in nurses of age 20–65 years. PMRs were significantly elevated for cancer of the pancreas and leukemia among those age 20 years and older. Elevated values were also observed for motor vehicle accidents and suicide among nurses in both age groups. Lower than expected mortality from degenerative heart disease and cerebrovascular accidents was seen in working age teachers (age 20–65 years). However, elevated PMRs were detected for carcinoma of the colon, breast, endometrium, brain, and melanoma. Among those 20 years and over, significantly elevated PMRs were also observed for cancers of the ovary and other digestive organs. Elevated PMRs were found for motor vehicle and aircraft accidents. Mortality from cirrhosis of the liver was lower than anticipated in both teachers and nurses. A number of significant PMRs declined when deaths of “homemakers” were withdrawn from the comparison group used to generate PMR values, suggesting that risk of death from various causes among women working outside the home differ from those seen in women who are predominantly in the home.  相似文献   
6.
Paraneoplastic hypercalcemia associated with adenosquamous carcinoma of the endometrium is described. This is the first reported case of a gynecologic cancer in which the paraneoplastic syndrome has been conclusively shown by immunohistochemical analysis to be due to ectopic parathormone.  相似文献   
7.
CA 125 regression: a model for epithelial ovarian cancer response   总被引:7,自引:0,他引:7  
The rate of decline of CA 125 in effectively treated epithelial ovarian cancer is described by the exponential regression curve CA 125 = EXP [i - s (days after surgery)]. In this equation i, the y-axis intercept, measures initial tumor burden whereas s, the slope of the regression curve, is determined by the extent of cytoreductive surgery and the subsequent response to chemotherapy. Departure from the regression curve uniformly results in progressive disease. In patients whose cancers had been completely removed, we calculated the mean half-life of CA 125 to be 10.4 days (range 4 to 21). In this case s = 0.0835 and characterizes the ideal regression rate. The model predicts that high-dose cisplatin chemotherapy (s = 0.0671) is more effective than low-dose cisplatin (s = 0.0380) (p less than 0.03) in eliminating residual cancer. Because s can be calculated within 2 to 3 months of treatment and then compared with s for the ideal regression curve and with the values of s reported for standard chemotherapy, evaluation of any new treatment protocol can be facilitated with this method.  相似文献   
8.
This study examined the utility of the Halstead-Reitan Neuropsychological Battery in the differential diagnosis of dementia, major depression, and general neurological impairment. Orthogonal contrasts between groups showed superior performance for depressives on most Halstead-Reitan subtests. Contrasts between organically impaired groups showed that these groups did not differ significantly (p >.05) on any of the Halstead-Reitan subtests. A step-wise discriminant analysis indicated that on the basis of neuropsychological variables alone, demented patients were differentiated from elderly depressed with clinical levels of accuracy. However, when neurologically impaired and demented patients were considered together in a single group reflecting organic impairment, hits increased dramatically. The results were discussed in terms of their implications for differentially diagnosing dementia and depression in the elderly.  相似文献   
9.
10.
The chick embryo chorioallantoic membrane was used to study the acute inflammatory response in the absence of contributions from the immune system. In preliminary experiments, lesions of wild-type cowpox virus strain Brighton (CPV-BR) and a 38K gene deletion mutant of CPV-BR (CPV-BR.D1) were compared with vaccinia virus (strains WR and Copenhagen), fowlpox virus, laryngotracheitis virus, and infectious tenosynovitis virus, and were ranked for degree of induced inflammation. The maximal and minimal inflammatory responses were observed with CPV-BR.D1 and CPV-BR viruses, respectively. CPV-BR.D1 lacks a 38K gene which encodes an anti-inflammatory 38-kDa protein that has homology to SERPINs. The kinetics and character of the inflammatory response were examined further in the wild-type CPV-BR and mutant CPV-BR.D1 infections using cell counts, electron microscopy, and assays for inflammatory cell activation. CPV-BR virus infection rapidly spread through the ectoderm, uniformly infecting all cells with the production of large amounts of virions and viral-induced cytopathic effect, but evoking little or no inflammatory response until 144 hr p.i. The CPV-BR.D1 infection, on the other hand, was rapidly contained by a dexamethasone-sensitive inflammatory response mainly of activated heterophils which was advanced by 36 hr p.i. Both infections resulted in disseminated disease with similar numbers of liver lesions and only a slight difference in the LD50, with the CPV-BR.D1 values being higher than that for CPV-BR virus. In this model, the acute inflammatory response alone is unable to prevent disseminated disease and associated mortality.  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