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   986篇
  免费   65篇
  国内免费   3篇
耳鼻咽喉   4篇
儿科学   10篇
妇产科学   12篇
基础医学   159篇
口腔科学   14篇
临床医学   106篇
内科学   213篇
皮肤病学   10篇
神经病学   123篇
特种医学   34篇
外科学   135篇
综合类   6篇
预防医学   43篇
眼科学   10篇
药学   83篇
中国医学   2篇
肿瘤学   90篇
  2023年   5篇
  2022年   13篇
  2021年   45篇
  2020年   22篇
  2019年   30篇
  2018年   41篇
  2017年   18篇
  2016年   23篇
  2015年   28篇
  2014年   32篇
  2013年   45篇
  2012年   91篇
  2011年   93篇
  2010年   44篇
  2009年   37篇
  2008年   78篇
  2007年   61篇
  2006年   54篇
  2005年   77篇
  2004年   58篇
  2003年   56篇
  2002年   47篇
  2001年   6篇
  2000年   1篇
  1999年   6篇
  1998年   4篇
  1997年   12篇
  1996年   2篇
  1995年   9篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1986年   2篇
  1980年   3篇
  1979年   2篇
  1978年   1篇
排序方式: 共有1054条查询结果,搜索用时 15 毫秒
1.
2.
3.
Iron-oxide nanoparticles (NPs) generated by environmental events are likely to represent health problems. α-Fe2O3 NPs were synthesized, characterized and tested in a model for toxicity utilizing human whole blood without added anticoagulant. MALDI-TOF of the corona was performed and activation markers for plasma cascade systems (complement, contact and coagulation systems), platelet consumption and release of growth factors, MPO, and chemokine/cytokines from blood cells were analyzed. The coronas formed on the pristine α-Fe2O3 NPs contained contact system proteins and they induced massive activation of the contact (kinin/kallikrein) system, as well as thrombin generation, platelet activation, and release of two pro-angiogeneic growth factors: platelet-derived growth factor and vascular endothelial growth factor, whereas complement activation was unaffected. The α-Fe2O3 NPs exhibited a noticeable toxicity, with kinin/kallikrein activation, which may be associated with hypotension and long-term angiogenesis in vivo, with implications for cancer, arteriosclerosis and pulmonary disease.  相似文献   
4.
5.
The literature regarding self-reported dental/oral health data suggests that certain self-reported information is valid. The objective of this study was to show whether self-perceived periodontal conditions can predict actual periodontal status measured by probing depth and radiographic bone level. Participants completed a questionnaire regarding systemic health, education, smoking status, oral hygiene habits and self-perception of their own periodontal status using a visual analog scale (VAS); they were examined clinically and radiographically. More than two-thirds self-perceived their periodontal status as between 5 and 8 (out of 10). Smoking was related to radiographic bone loss, but not to the number of sites with PD > or = 5mm. Periodontal self-assessment correlated with the number of sites with PD > or = 5mm (p = 0.013), the number of sites with radiographic bone loss > or = 3 mm (p = 0.045), as well as with plaque index (p = 0.003) and daily flossing (p = 0.022). For a cutoff of 5 in the VAS score, sensitivity of 84% and specificity of 22% were found for high PD and sensitivity of 85% and specificity of 24% for bone loss.  相似文献   
6.

Objective

Certain functional somatic syndromes (FSSs) such as fibromyalgia and irritable bowel syndrome are accompanied by diffuse pain amplification. Women with interstitial cystitis/bladder pain syndrome (IC/BPS) have numerous FSSs, as well as other non-bladder syndromes (NBSs) that are linked to the FSSs. They also report multiple surgeries. Since pain is a common indication for surgery, we tested the hypothesis that NBSs were associated with surgeries.

Methods

We interviewed 312 incident IC/BPS cases and controls on NBSs and number of surgeries before the index date (for cases, IC/BPS onset date). Poisson and logistic regression analyses adjusted for age, race, educational level, and menopause.

Results

Number of surgeries increased with number of NBSs in both cases and controls whether chronic pelvic pain (CPP), the only NBS generally accepted as an indication for surgery, was present or not. Logistic regression analysis showed that among cases CPP was the only individual NBS associated with a history of multiple surgeries, and then only modestly [odds ratio (OR) 1.9, confidence intervals (CI) 1.06, 3.2]. By far the strongest association was the number of NBSs. The OR for multiple surgeries increased with number of NBSs: for cases with 4–5 NBSs the OR was 14.1 (1.8, 113) and with 6–9 NBSs, 33.1 (3.9, 279). Controls had fewer syndromes and fewer surgeries and this linkage was less prominent.

Conclusion

Among IC/BPS cases, the number of NBSs was strongly correlated with the number of surgeries. Understanding temporal relationships will be necessary to explore causal linkages and may modify surgical practice.  相似文献   
7.
Background contextLumbar interbody fusion (LIF) techniques have been used for years to treat a number of pathologies of the lower back. These procedures may use an anterior, posterior, or combined surgical approach. Each approach is associated with a unique set of complications, but the exact prevalence of complications associated with each approach remains unclear.PurposeTo investigate the rates of perioperative complications of anterior lumbar interbody fusion (ALIF), posterior/transforaminal lumbar interbody fusion (P/TLIF), and LIF with a combined anterior-posterior interbody fusion (APF).Study design/settingRetrospective review of national data from a large administrative database.Patient samplePatients undergoing ALIF, P/TLIF, or APF.Outcome measuresPerioperative complications, length of stay (LOS), total costs, and mortality.MethodsThe Nationwide Inpatient Sample database was queried for patients undergoing ALIF, P/TLIF, or APF between 2001 and 2010 as identified via International Classification of Diseases, ninth revision codes. Univariate analyses were carried out comparing the three cohorts in terms of the outcomes of interest. Multivariate analysis for primary outcomes was carried out adjusting for overall comorbidity burden, race, gender, age, and length of fusion. National estimates of annual total number of procedures were calculated based on the provided discharge weights. Geographic distribution of the three cohorts was also investigated.ResultsAn estimated total of 923,038 LIFs were performed between 2001 and 2010 in the United States. Posterior/transforaminal lumbar interbody fusions accounted for 79% to 86% of total LIFs between 2001 and 2010, ALIFs for 10% to 15%, and APF decreased from 10% in 2002 to less than 1% in 2010. On average, P/TLIF patients were oldest (54.55 years), followed by combined approach (47.23 years) and ALIF (46.94 years) patients (p<.0001). Anterior lumbar interbody fusion, P/TLIF, and combined surgical costs were $75,872, $65,894, and $92,249, respectively (p<.0001). Patients in the P/TLIF cohort had the greatest number of comorbidities, having the highest prevalence for 10 of 17 comorbidities investigated. Anterior-posterior interbody fusion group was associated with the greatest number of complications, having the highest incidence of 12 of the 16 complications investigated.ConclusionsThese data help to define the perioperative risks for several LIF approaches. Comparison of outcomes showed that a combined approach is more expensive and associated with greater LOS, whereas ALIF is associated with the highest postoperative mortality. These trends should be taken into consideration during surgical planning to improve clinical outcomes.  相似文献   
8.
9.

Objective

The aim of the study was to evaluate the operative and functional results after individual, patient-tailored aortic root repair in marfanoid patients.

Methods

Among 518 patients who underwent operation between 2002 and January 2016, using patient-tailored aortic root repair with isolated sinus replacement, 42 patients fulfilled the original Ghent criteria. None/trivial, mild, moderate, and severe insufficiency grades were present in 5, 16, 10, and 11 patients, respectively.

Results

The repair was adjusted to the existing aortic annulus diameter. Replacement of 1, 2, or 3 sinuses of Valsalva was performed in 1, 14, and 27 patients, respectively. Concomitant cusp repair was performed in 17 patients (40.5%), and 10 patients (23.8%) underwent arch repair (total in 3). All patients survived surgery, and the follow-up (mean, 6.1 ± 3.1; range, 0.8-14.2 years) was 100% complete. No patient had a change in the form or size of the aortic neo-root, especially the size of aortic annulus and sinotubular junction during the follow-up time. No and trivial/mild insufficiency were present in 22 and 18 patients, respectively, and 2 patients with recurrent aortic insufficiency caused by cusp pathology underwent aortic valve replacement 43 and 66 months after the primary surgery, respectively. Thus, the estimated survival free from aortic valve/root reoperation for any reason at 5 and 8 years was 96.8% ± 3.2% and 91.4% ± 6.0%, respectively.

Conclusions

Patient-tailored root repair using isolated sinus replacement is an effective and durable method of valve-sparing repair in select marfanoid patients with a satisfactory quality of aortic cusps, which seems to be decisive for long-term valve function.  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