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   30616篇
  免费   1472篇
  国内免费   155篇
耳鼻咽喉   490篇
儿科学   930篇
妇产科学   854篇
基础医学   3175篇
口腔科学   871篇
临床医学   2590篇
内科学   6604篇
皮肤病学   629篇
神经病学   1423篇
特种医学   992篇
外国民族医学   10篇
外科学   5165篇
综合类   835篇
现状与发展   1篇
一般理论   34篇
预防医学   2028篇
眼科学   821篇
药学   2642篇
  5篇
中国医学   195篇
肿瘤学   1949篇
  2024年   212篇
  2023年   450篇
  2022年   1205篇
  2021年   1718篇
  2020年   942篇
  2019年   1187篇
  2018年   1465篇
  2017年   909篇
  2016年   944篇
  2015年   1057篇
  2014年   1340篇
  2013年   1631篇
  2012年   2235篇
  2011年   2302篇
  2010年   1198篇
  2009年   946篇
  2008年   1437篇
  2007年   1506篇
  2006年   1355篇
  2005年   1161篇
  2004年   1092篇
  2003年   965篇
  2002年   868篇
  2001年   445篇
  2000年   425篇
  1999年   384篇
  1998年   197篇
  1997年   138篇
  1996年   125篇
  1995年   131篇
  1994年   96篇
  1993年   77篇
  1992年   173篇
  1991年   158篇
  1990年   163篇
  1989年   135篇
  1988年   127篇
  1987年   117篇
  1986年   124篇
  1985年   113篇
  1984年   89篇
  1983年   111篇
  1982年   57篇
  1981年   54篇
  1979年   94篇
  1978年   64篇
  1977年   68篇
  1976年   60篇
  1975年   54篇
  1974年   52篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.

Background

Anterior knee pain (AKP) remains a complex issue affecting patient satisfaction after total knee arthroplasty. Several radiographic parameters have been shown to be causative factors with various designs. The aim of this study is to evaluate the known radiographic parameters of AKP and clinical outcomes (ie, AKP) in the setting of a modern prosthesis with an anatomic patella button.

Methods

Between July 2012 and December 2013, 90 total knee arthroplasties received 3 skyline views taken at 30°, 45°, and 60°. A patient-administered questionnaire was administered at 2-year follow-up to assess the incidence of AKP, painless noise, and satisfaction. Radiographs were analyzed for patellofemoral overstuffing, patellar tilt, and patellar displacement, and evaluated the patella resection angle.

Results

On the patient-administered questionnaire, 10 (11.1%) patients reported AKP of a mild-to-moderate nature. Thirty-one had the best view at 30 Merchant views, 24 had best views at 45, and 35 had best views at 60. We found that patellar resection angle correlated with AKP (odds ratio 1.21, P = .044) and painless noise (odds ratio 1.22, P = .034). Patellar displacement and patellofemoral stuffing did not correlate with AKP or painless noise. No radiographic measurements correlated with changes in Knee Society Score pain or function scores or range of motion.

Conclusion

We found that a patellar resection angle correlated with the incidence of AKP and painless noise at 2-year follow-up. We failed to find any correlation with patellofemoral overstuffing, patellar displacement, or patellar tilt with clinical outcomes. We recommend the use of 3 Merchant views to fully evaluate the patellofemoral joint.  相似文献   
3.

Background

As a recently discovered adipokine, nesfatin-1 is conducive to insulin sensitivity, lipid profile, energy balance, and probably obesity.

Objective

The aim of the present study was to investigate the effect of upper-body resistance exercise training (RET) on nesfatin-1 levels, insulin resistance, lipid profile, and body composition in obese paraplegic men.

Methods

Twenty obese paraplegic men were randomly assigned into control and upper-body RET groups. Upper-body RET was performed for 8 weeks, 3 sessions per week at an intensity corresponding to 60–80% maximum amount of force that can be generated in one maximal contraction in 5 stations (bench press, seated rows, sitting lat pulldown, arm extension, and arm curls). Body fat percentage was determined according to 4-sites skinfold protocol of Durnin and Womersley and Siri equation. Obesity for spinal cord injury patients in the current study was set at BMI >22?kg/m2. Data were statistically analyzed by paired and independent t-test (P?<?0.05).

Results

We found significant improvements in serum levels of nesfatin-1 (21.13%), insulin sensitivity (8.95%), and high-density lipoprotein (10.87%). Other lipid profile markers, i.e. low-density lipoprotein (4.32%), cholesterol (8.20%), and triglyceride (15.10%) reduced significantly after upper-body RET. Moreover, upper-body RET led to a significant reduction in body mass index (2.36%), body fat percentage (2.79%), and waist-to-hip ratio (2.40%).

Conclusion

Upper-body RET improved insulin sensitivity, lipid profile, and body composition in paraplegic men. Serum nefastin-1 may be a potential marker of success in weight management in this population.  相似文献   
4.
Enterococci are commensal micro-organisms present in the gastrointestinal tract of humans. Although normally innocuous to the host, strains of enterococcus exhibiting resistance to vancomycin (VRE) have been associated with high rates of infection and mortality in immunocompromised patients. Decolonization of VRE represents a key strategy to curb infection in highly-susceptible patients. However, there is a dearth of decolonizing agents available clinically that are effective against VRE. The present study found that niclosamide, an anthelmintic drug, has potent antibacterial activity against clinical isolates of vancomycin-resistant Enterococcus faecium (minimum inhibitory concentration 1–8?µg/mL). E. faecium mutants exhibiting resistance to niclosamide could not be isolated even after multiple (10) serial passages. Based upon these promising in-vitro results and the limited permeability of niclosamide across the gastrointestinal tract (when administered orally), niclosamide was evaluated in a VRE colonization-reduction murine model. Remarkably, niclosamide outperformed linezolid, an antibiotic used clinically to treat VRE infections. Niclosamide was as effective as ramoplanin in reducing the burden of vancomycin-resistant E. faecium in the faeces, caecal content and ileal content of infected mice after only 8 days of treatment. Linezolid, in contrast, was unable to decrease the burden of VRE in the gastrointestinal tract of mice. The results obtained indicate that niclosamide warrants further evaluation as a novel decolonizing agent to suppress VRE infections.  相似文献   
5.
The Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) was developed and validated to weigh the burden of pretransplantation comorbidities and estimate their impact on post-transplantation risks of nonrelapse mortality (NRM). Recently, the HCT-CI was augmented by the addition of both age and the values of 3 markers: ferritin, albumin, and platelet count. So far, research involving The HCT-CI has been limited almost exclusively to recipients of allogeneic hematopoietic cell transplantation (HCT) from HLA-matched grafts. To this end, we sought to investigate the discriminative capacity of an augmented comorbidity/age index among 724 recipients of allogeneic HCT from HLA-mismatched (n = 345), haploidentical (n = 117), and umbilical cord blood (UCB; n = 262) grafts between 2000 and 2013. In the overall cohort, the augmented comorbidity/age index had a higher c-statistic estimate for prediction of NRM compared with the original HCT-CI (.63 versus .59). Findings were similar for recipients of HLA-mismatched (.62 versus .59), haploidentical (.60 versus .54), or UCB grafts (.65 versus .61). Compared with patients with an HCT-CI score ≥4, those with a score <4 had a higher survival rate among recipients of HLA-mismatched (55% versus 39%; P < .0008), HLA-haploidentical (58% versus 38%; P = .01), or UCB (67% versus 48%; P = .004) grafts. Our results demonstrate the utility of the augmented comorbidity/age index as a valid prognostic tool among recipients of allogeneic HCT from alternative graft sources.  相似文献   
6.
7.
Performance of Five Commercially Available Tooth Color-Measuring Devices   总被引:3,自引:0,他引:3  
PURPOSE: Visual tooth color assessment is neither accurate nor precise due to various subjective and objective factors. As newly developed tooth color-measuring devices for dental application provide the possibility of a more objective means of color determination, their performances in vitro and in vivo must be evaluated. The objective of this study was to evaluate the accuracy and precision of five commercially available tooth color-measuring devices in standardized and in clinical environments. MATERIALS AND METHODS: In an in vitro study, standards (A1, A2, A3, A3.5, and A4 shade tabs of Vita Lumin) were measured five times with five electronic devices (ShadeScan, Easyshade, Ikam, IdentaColor II, and ShadeEye) by two operators. In an in vivo study, the right upper central incisors of 25 dental students were measured with the same electronic devices by a single operator. Vita shade tab codes were expressed as CIE (International Commission on Illumination) L*a*b* values and in terms of the precision and accuracy of DeltaE color differences. The Mann-Whitney statistical test was used to analyze the differences between the two operators in the in vitro study, and the Kruskal-Wallis one-way analysis of variance on ranks with the post-hoc Tukey test was used to analyze the accuracy and precision of electronic devices. RESULTS: No statistically significant difference was found between the different operators in the in vitro study. The obtained precision was Easyshade > ShadeScan approximately equal Ikam > IdentaColor II > ShadeEye. The obtained accuracy was Easyshade > ShadeScan approximately equal Ikam > ShadeEye > IdentaColor II. In the in vivo study, the Easyshade and the Ikam were the most precise, and the ShadeEye and the IdentaColor II were more precise than the ShadeScan. With respect to accuracy, there was no statistical difference between the ShadeScan, Ikam, and the Easyshade. The IdentaColor II was considered inaccurate (DeltaE(a)= 3.4). CONCLUSIONS: In the clinical setting, the Easyshade and Ikam systems were the most reliable. The other devices tested were more reliable in vitro than in vivo.  相似文献   
8.
The Index of Orthodontic Treatment Need (IOTN) has been used in dental epidemiology and to prioritize orthodontic treatment. The aim of this paper was to use the aesthetic component (AC) of the IOTN to measure agreement between normative and perceived orthodontic need amongst school children. Three hundred and seventy-eight children aged 11-14 years, enrolled in London UK state schools participated in this survey. The study focused on three ethnic groups: white, black and South Asian. Townsend deprivation scores suggested that the children were from areas of high socio-economic deprivation. Logistic regression analysis was carried out for agreement between normative and perceived need at each threshold value. Perceived need for braces, ethnic background, social class and hours of television viewing were significant variables. Black pupils were significantly less likely to concur on normative and perceived need scores, tending to perceive less need for treatment than did the dentist. Subjects from lower social classes were significantly more likely to concur on normative and perceived need scores. In conclusion, the study showed that using the IOTN AC at various points along the scale, different influences play a significant role in agreement/disagreement between normative and perceived needs, indicating that patient-clinician agreement regards orthodontic treatment is sensitive to several cultural factors.  相似文献   
9.
We describe an unusual adverse reaction that was probably caused by taking ecstasy: the patient developed widespread oral and oropharyngeal mucosal oedema, which was triggered after he had taken ecstasy and alcohol. The reaction to this could have been fatal.  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