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   1719篇
  免费   78篇
  国内免费   21篇
耳鼻咽喉   57篇
儿科学   26篇
妇产科学   53篇
基础医学   143篇
口腔科学   24篇
临床医学   204篇
内科学   410篇
皮肤病学   14篇
神经病学   95篇
特种医学   81篇
外科学   391篇
综合类   7篇
一般理论   4篇
预防医学   53篇
眼科学   44篇
药学   52篇
中国医学   1篇
肿瘤学   159篇
  2023年   15篇
  2022年   14篇
  2021年   40篇
  2020年   27篇
  2019年   45篇
  2018年   50篇
  2017年   43篇
  2016年   56篇
  2015年   57篇
  2014年   106篇
  2013年   108篇
  2012年   174篇
  2011年   155篇
  2010年   107篇
  2009年   76篇
  2008年   163篇
  2007年   135篇
  2006年   106篇
  2005年   94篇
  2004年   96篇
  2003年   55篇
  2002年   53篇
  2001年   12篇
  2000年   2篇
  1999年   5篇
  1997年   2篇
  1996年   2篇
  1995年   8篇
  1993年   6篇
  1992年   1篇
  1983年   1篇
  1979年   1篇
  1977年   2篇
  1973年   1篇
排序方式: 共有1818条查询结果,搜索用时 31 毫秒
1.
2.

Objective

The aim of the study was to present the results for patients with atherosclerotic aneurysm of the descending thoracic aorta (DTA) treated with a novel thoracic stent graft.

Methods

A single-center retrospective review of prospectively collected data was performed. We extracted demographic variables as well as atherosclerotic comorbidities and operation-related and imaging-related data from patients' medical records. We estimated technical success rate, in-hospital and 30-day mortality, and mortality at the end of follow-up as well as complication and reintervention rate in our study cohort. Follow-up computed tomography angiography was performed after 1 month and 6 months and yearly thereafter.

Results

A total of 30 patients (80% male; mean age, 73.7 ± 6.33 years) were treated with Ankura Thoracic Stent Graft (Lifetech, Shenzhen, China) for DTA aneurysm from February 2014 until June 2017. Technical success of the thoracic endovascular aortic repair (TEVAR) was 97% (29/30 patients). A surgical conduit was required in one patient; in three patients, we intentionally covered the left subclavian artery because of insufficient proximal landing zone. No aorta-related deaths were recorded during follow-up. During the early postoperative period, two patients (7%) with long DTA coverage developed paralysis or paraparesis, which immediately resolved after lumbar drainage. No renal complications requiring dialysis were observed. One patient (3%) developed postoperative pulmonary infection, whereas access site complications were 7%. Two symptomatic patients treated outside instructions for use (7%) developed early type IA endoleak and one patient (3%) developed type IB endoleak; type II endoleak was recorded in 3% of the study cohort. During the 30-day postoperative period, two patients died of non-TEVAR-related causes, one of gastrointestinal bleeding and the other of pulmonary infection. During a median follow-up of 31.7 (range, 38.4) months, two more patients also died of non-TEVAR-related causes, one of stroke from carotid artery disease and the other of motor vehicle trauma. In the rest of the cohort, no other adverse events were noted.

Conclusions

This novel endograft showed early evidence of a safe, effective, and durable endoprosthesis for the treatment of DTA aneurysms.  相似文献   
3.
4.
BackgroundObesity and high body mass index (BMI) are associated with increased incidence of multiple myeloma (MM). MM usually evolves from a precursor asymptomatic disease, namely monoclonal gammopathy of undetermined significance (MGUS). MGUS progresses to MM at a 1% annual rate; however, risk factors predisposing to MGUS are not completely understood. We conducted a systematic review to assess the relationship between obesity and high BMI with MGUS prevalence and progression to MM. To our knowledge, this is the first systematic review evaluating the role of obesity in MGUS.Patients and MethodsWe searched the Medline database and ClinicalTrials.gov for studies investigating BMI and obesity association with MGUS incidence and progression. The algorithm consisted of a predefined combination of the words “obesity,” “obese,” “body mass index,” “overweight,” “diet,” “nutrition,” “food,” “dietary,” “adiponectin,” “monoclonal gammopathy,” and “MGUS”.ResultsOverall, 12 articles were retrieved, including 11 eligible articles and 1 clinical trial. More than 57,068 patients were evaluated in this systematic review. Discrepancies between the identified studies were noted. Multiple studies support the notion that obesity or high BMI are positively linked to MGUS prevalence and transition to MM. In contrast, other studies revealed no such association. Visceral adipose tissue metabolic activity and decreased adiponectin concentrations were identified as biomarkers of MGUS progression to MM.ConclusionObesity and increased BMI seem to be implicated both in MGUS development and progression to MM. Further studies should be designed to confirm this hypothesis.  相似文献   
5.
6.
7.
Adenoid cystic carcinoma of the parotid gland is relatively rare. According to a retrospective study of the medical records and histopathology files of 514 cases of parotid tumors operated at our hospital over a period of 18 years, adenoid cystic carcinoma represented only 2.3% of all parotid gland neoplasms, a total of 12 cases. In our records we retrieved only one documented case of adenoid cystic carcinoma that originated in the parotid gland subsequent to superficial parotidectomy for a benign lesion (pleomorphic adenoma).An even more exceptional presentation of adenoid cystic carcinoma is as a bilobed tumor extending from the post auricular to the temporal and zygomatic region. The management of this case is presented along with a brief review of the literature concerning the evaluation and management of this rare entity.  相似文献   
8.
: To assess the short-term effects of pressure support ventilation in adult respiratory distress syndrome (ARDS), we studied 17 patients with moderate to severe ARDS using mandatory rate ventilation (MRV), a servocontrolled mode of PSV having respiratory rate as the targeted parameter.: Based on the duration of ARDS, the patients were divided into two groups: Group 1, early ARDS (duration up to 1 week), 10 patients; Group 2, intermediate ARDS (duration between 1 and 2 weeks). The patients were initially ventilated with assisted mechanical ventilation then with MRV, and finally with controlled mechanical ventilation. After a 20-minute period allowed for stabilization in each mode, ventilatory variables, gas exchange, hemodynamics, and patient's inspiratory effort were evaluated.: During MRV blood gases, airway pressures and hemodynamic variables remained within acceptable limits in all patients. Compared with assisted mechanical ventilation, during MRV, patients of group 1 decreased their Vt and V? (from 0.64 ± 0.04 to 0.42 ± 0.03 L/sec) and increased their Ti/Tt (from 0.39 ± 0.03 to 0.52 ± 0.03). f did not change. PAO2 - PaO2 and Q?s/Q?t decreased (from 306 ± 16 to 269 ± 15 mm Hg, and from 20.2 ± 1.4 to 17.5 ± 1.1, respectively), while PaCO2 increased (from 44 ± 3 to 50 ± 3 mm Hg). On the contrary, patients of group 2 increased their Vt (from 0.69 ± 0.02 to 0.92 ± 0.09 L), decreased their f (from 22.3 ± 0.5 to 19.3 ± 0.3 b/min), although they did not change their V? and Ti/Tt. PAO2 - PaO2 and Q?s/Q?t remained stable. PaCO2 diminished (from 39 ± 3 to 34 ± 3 mm Hg). Pressure support level was higher in group 2 than in group 1 (29.4 ± 3.0 v 19.8 ± 2.9 cm H2O).: We conclude that (1) PSV delivered by MRV may adequately ventilate patients with moderate to severe ARDS, preserving gas exchange and hemodynamics, at least for the short period tested; (2) early and intermediate ARDS respond in a different manner to MRV in terms of breathing pattern, gas exchange, and level of pressure assistance; and (3) patients with early ARDS are those who have an improvement in intrapulmonary oxygenation probably due, at least in part, to alveolar recruitment augmented by active diaphragmatic contraction.  相似文献   
9.
10.
The aim of this project was to translate, culturally adapt and validate the Internet Addiction Test (IAT) in Greek adults. Twenty-one post-graduate medical students participated in the cultural adaptation procedure and 151 both post- and under-graduate medical students in the validation process. The internal consistency shown by a Cronbach’s alpha was 0.91. Two-week test–retest reliability was rtt = 0.84, p < 0.001. Face validity was affirmed by 83.6 % of the students. In terms of convergent validity, the hours of daily internet use were positively correlated with IAT score (rho = 0.48, p < 0.001). Moreover, IAT scores were higher in students that reported use of online gambling (40.5 vs 29.2, p = 0.004), pornographic sites (36.5 vs 28.0, p = 0.003) and online games (35.6 vs 28.2, p = 0.009). Exploratory factor analysis revealed three interpretable factors for the IAT, “Psychological/Emotional Conflict”, “Time Management” and “Neglect Work”, that showed good internal consistency and concurrent validity, explaining 55.3 % of the variance. The Greek version of IAT has shown good psychometric properties, comparable with the original IAT and the previously published translated versions, and can be a useful tool in future studies on internet addiction.  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