首页 | 官方网站   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   93856篇
  免费   5925篇
  国内免费   1792篇
医药卫生   101573篇
  2024年   182篇
  2023年   2233篇
  2022年   3044篇
  2021年   4815篇
  2020年   4673篇
  2019年   4161篇
  2018年   4029篇
  2017年   3412篇
  2016年   3330篇
  2015年   3515篇
  2014年   7107篇
  2013年   6573篇
  2012年   5230篇
  2011年   5619篇
  2010年   4514篇
  2009年   4344篇
  2008年   4240篇
  2007年   4158篇
  2006年   3666篇
  2005年   3124篇
  2004年   2685篇
  2003年   2167篇
  2002年   1736篇
  2001年   1566篇
  2000年   1396篇
  1999年   1258篇
  1998年   1022篇
  1997年   986篇
  1996年   792篇
  1995年   660篇
  1994年   595篇
  1993年   494篇
  1992年   422篇
  1991年   407篇
  1990年   295篇
  1989年   278篇
  1988年   305篇
  1987年   280篇
  1986年   222篇
  1985年   279篇
  1984年   311篇
  1983年   186篇
  1982年   203篇
  1981年   185篇
  1980年   175篇
  1979年   119篇
  1978年   90篇
  1977年   101篇
  1976年   101篇
  1975年   90篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
71.
72.

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   
73.

Background

The Lancet Commission on Global Surgery highlighted global surgical need but offered little insight into the specific surgical challenges of children in low-resource settings. Efforts to strengthen the quality of global pediatric surgical care have resulted in a proliferation of partnerships between low-and middle-income countries (LMICs) and high-income countries (HICs). Standardized tools able to reliably measure gaps in delivery and quality of care are important aids for these partnerships. We undertook a systematic review (SR) of capacity assessment tools (CATs) focused on needs assessment in pediatric surgery.

Methods

A comprehensive search strategy of multiple electronic databases was conducted per PRISMA guidelines without linguistic or temporal restrictions. CATs were selected according to pre-defined inclusion criteria. Articles were assessed by two independent reviewers. Methodological quality of studies was appraised using the COSMIN checklist with 4-point scale.

Results

The search strategy generated 16,641 original publications, of which three CATs were deemed eligible. Eligible tools were either excessively detailed or oversimplified. None used weighted scores to identify finer granularity between institutions. No CATs comprehensively included measures of resources, outcomes, accessibility/impact and training.

Discussion

The results of this study identify the need for a CAT capable of objectively measuring key aspects of surgical capacity and performance in a weighted tool designed for pediatric surgical centers in LMICs.

Type of Study

Systematic Review.

Level of Evidence

II.  相似文献   
74.
75.
Oral and maxillofacial surgery (OMS) teaching is set to undergo a paradigm shift towards competency-based training. With increasing focus on resident skill development and patient safety, computerized simulators are likely to play a more mainstream role in OMS training. A systematic review of the available literature was conducted, in accordance with the PRISMA guidelines, to highlight the scope of computerized simulation in OMS teaching. A PubMed search was performed by two independent reviewers, and 35 articles published in English between 2010 and 2021 that reported the use of computerized simulation for teaching maxillofacial procedures were included in the analysis. Eight articles on minor oral surgery, seven on orthognathic surgery, five on maxillofacial trauma, five on cleft lip and palate surgery, three articles each on nerve block techniques, endoscopic procedures, and reconstructive surgery, and one article on fibre-optic intubation reported the use of computerized simulation that can be applied to OMS training. Ten randomized controlled trials were identified in the search. However there was marked heterogeneity among the studies. Simulator training for skill acquisition mentored by an expert OMS educator could offer holistic resident training; however more studies that test common themes of resident training such as knowledge acquisition and skill development are necessary.  相似文献   
76.
77.
78.

Objective

Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.

Methods

Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.

Results

We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.

Conclusions

Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients.  相似文献   
79.
Chronic pain in the UK affects up to 43% of the population. The consequences include physical and psychological distress, loss of function, employment, family and social strain and increased utilization of healthcare services. Modern pain management services operate across primary, secondary and tertiary care and incorporate general practitioners, psychologists, physiotherapists, pharmacists, specialist nurses, pain physicians and surgeons. This allows for a coordinated approach to chronic pain, engaging the patient in a structured pathway from conservative measures, through to surgery if necessary. Surgical interventions have been utilized effectively throughout the 20th century for the treatment of a variety of conditions, some of which are now effectively managed with improved pharmacological approaches or novel neuromodulation techniques. Ablative procedures that aim to permanently interrupt the pain pathway still represent the final solution for some conditions, particularly those with cancer associated pain; however, the search for less invasive, less risky measures continues. This is stimulated by an increased understanding of the neurobiology of pain transmission and the physiological changes which occur in persistent pain.  相似文献   
80.
Purpose: To study epidemiology and clinical findings of cataract in HIV+ patients.

Methods: A total of 32 HIV+ patients, 11 with uveitis/retinitis before surgery and 21 without, mean follow-up 44.9 ± 36.6 months, and 114 HIV- patients, 57 with uveitis/retinitis before surgery and 57 without, were retrospectively compared.

Results: Visual acuity improved in all HIV+ patients (p < 0.001), who were younger (p = 0.01) and more frequently males (p = 0.027). HIV+ patients with uveitis prior surgery improved less (p = 0.046) than HIV- (p < 0.001); their anterior chamber inflammation was similar to baseline. Male sex (p = 0.005), younger age (p < 0.001), dyslipidaemia (p = 0.058), HBV+ (p = 0.037), and unilateral cataract (p = 0.001) were more frequent in HIV+ patients with senile cataract, but they showed the same postoperative course as HIV- patients.

Conclusion: Cataract surgery in HIV+ patients is safe and effective. Uveitis prior to surgery did not significantly affect the postoperative course. Systemic comorbidities are more frequent in HIV+ patients with senile cataract than in HIV- subjects.  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-23

京公网安备 11010802026262号