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   1604篇
  免费   68篇
  国内免费   11篇
耳鼻咽喉   54篇
儿科学   127篇
妇产科学   57篇
基础医学   133篇
口腔科学   100篇
临床医学   174篇
内科学   315篇
皮肤病学   69篇
神经病学   97篇
特种医学   77篇
外科学   237篇
综合类   24篇
预防医学   30篇
眼科学   33篇
药学   80篇
中国医学   3篇
肿瘤学   73篇
  2024年   2篇
  2023年   19篇
  2022年   25篇
  2021年   44篇
  2020年   21篇
  2019年   51篇
  2018年   36篇
  2017年   32篇
  2016年   56篇
  2015年   67篇
  2014年   90篇
  2013年   98篇
  2012年   122篇
  2011年   130篇
  2010年   75篇
  2009年   61篇
  2008年   125篇
  2007年   141篇
  2006年   130篇
  2005年   108篇
  2004年   95篇
  2003年   85篇
  2002年   35篇
  2001年   14篇
  2000年   6篇
  1999年   5篇
  1998年   4篇
  1997年   3篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
排序方式: 共有1683条查询结果,搜索用时 0 毫秒
31.
AimThe partial pulpotomy can offer a successful outcome for the treatment of traumatic complicated crown fractures. The aim of this clinical report was to evaluate the effect of mineral trioxide aggregate (MTA) in apexogenesis of traumatized immature permanent incisors with pulp exposure.Case reportAccording to clinical and radiological examinations complicated crown fractures and open apices were identified in 13 permanent upper incisors in ten patients (age range 7–10 years). Partial pulpotomy procedures were performed and the teeth were treated with MTA. In this report, periodic clinical and radiological follow-ups were performed. At recall examinations, all teeth were asymptomatic, and clinical and radiological investigations revealed excellent healing patterns with continued apexogenesis.ConclusionRegular examination of immature traumatized permanent teeth is critical for vitality and apexification. In this report, clinical and radiological findings confirm that partial pulpotomy with MTA is a reliable and effective treatment approach in apexogenesis of traumatized immature permanent incisors with pulp exposure.  相似文献   
32.
33.
34.

Purpose

Atherosclerosis is responsible for the high mortality rate in end-stage renal disease patients. Defining risk factors for atherosclerosis may lead to reduction in cardiovascular disease through modification of these factors. Peritoneal dialysis (PD) patients are subjected to high glucose loads on a daily basis, which results in considerable weight gain and an increase in waist circumference (WC). WC as an indicator of abdominal obesity is a risk factor for atherosclerosis in the general population. Carotid artery intima media thickness (CIMT) measurement is a reliable method for the detection of early atherosclerosis. The aim of this study was to investigate the relationship between WC and CIMT and to define risk factors associated with CIMT in PD patients.

Methods

Fifty-five PD patients and 40 healthy controls were included. Atherosclerosis was assessed using measurement of CIMT. Fasting blood was collected for analysis. Anthropometric parameters (age, weight, BMI, and WC) were measured.

Results

Peritoneal dialysis patients had higher WC (93.9 ± 1.7 vs. 87.3 ± 1.2 cm, p < 0.05) and CIMT (0.70 ± 0.02 vs. 0.57 ± 0.01 mm, p < 0.01) than the control group. On univariate analysis, age, WC, plaque formation, and D/P creatinine were positively correlated with CIMT, whereas residual renal function, albumin, ultrafiltration volume, and D/D0 glucose were negatively correlated. On multivariate analysis, only age, WC, and plaque formation showed correlation (p < 0.001).

Conclusions

Carotid artery intima media thickness is associated with age, plaque formation, and WC in PD patients. WC measurement is a simple, inexpensive, reproducible, and reliable method of evaluating atherosclerosis risk in PD patients and should be assessed at every visit. Appropriate counsel should be provided to patients with greater WC who are deemed to be at risk for atherosclerosis.  相似文献   
35.

Introduction

Practitioners have noted a striking increase in the number of young patients under the age of 40 years old who develop esophageal adenocarcinoma. The aim of this study was to characterize the presentation, pathology and therapeutic outcome of these young patients.

Methods

The records of patients who presented to the Foregut Surgical Service at the University of Southern California with esophageal adenocarcinoma between 2000 and 2007 were retrospectively reviewed. The presentation, tumor stage and histology, therapy and outcome of the patients under the age of 40 were compared to those ≥40.

Results

Of the 374 patients reviewed, 20 (5 %) were under the age of 40. There were two patients in their second and 18 in their third decade of life. The youngest patient was 25 years old. A history of gastroesophageal reflux disease or Barrett’s esophagus was less common in patients <40 than in those ≥40; 15 and 5 % compared to 61 and 46 %. Similarly, patients <40 had a significantly longer time interval between the onset of symptoms and the diagnosis of their cancer than those ≥40; 4.5 vs. 2 months, p?=?0.04. They also had a higher prevalence of stage IV disease (30 vs. 6 %, p?=?0.0003), a shorter time to recurrence (9.5 vs.19 month, p?=?0.002), and a poorer median survival (17 vs. 43 month, p?=?0.04).

Conclusion

Esophageal adenocarcinoma in patients <40 years old commonly presents with an advanced stage of the disease and an associated poor survival. This is likely due to a low index of suspicion that dysphagia seen in younger patients is due to a malignancy.  相似文献   
36.
37.
Conclusion: IBCT technique should be preferred owing to its high graft survival rate and ABG gain. While no significant difference was found in middle ear pressures between ears that underwent IBCT and normal ears, compliance values were found to be decreased in patients undergoing IBCT. However, the lack of correlation between ABG gain and compliance values indicated that compliance increase had no effect on post-operative ABG results. Objective: The aim of the present study was to compare tympanometric and audiological parameters in patients undergoing inlay butterfly cartilage tympanoplasty (IBCT) with their normal ears and to determine their difference with normal ear tympanometric parameters. Methods: Overall, 25 patients that underwent an operation between August 2010–May 2014 were included in the present study. In 13 of these patients, the ear that did not undergo operation was normal. 0.5, 1, 2, 4?kHz pure sound average values, tympanometric measurements and compliance values of normal and operated ears were compared. Results: The graft survival rate in patients was found to be 92%. Mean pre-operative air–bone gap (ABG) was 16.4?±?5.4 in patients, while mean post-operative ABG was 10.9?±?5.8, with a statistically significant difference (p?=?0.001) While there was no significant difference between operated and normal ears of patients in terms of middle ear pressure (0.441), compliance values were significantly higher in normal ears than those in operated ears (0.032). When post-operative ABG gain was compared with compliance values, no significant correlation was found between ABG gain and compliance measurements (r?=??0.025 and p?=?0.936).  相似文献   
38.
International Urology and Nephrology - Acute kidney injury (AKI) in COVID-19 patients is associated with poor prognosis. However, the incidence, risk factors and potential outcomes of AKI in...  相似文献   
39.
The study was undertaken to search whether pedicle selection for ischemic preconditioning (IP) and duration of global ischemia applied after IP influenced efficacy of IP on flap viability in epigastric adipocutaneous island flap with bilateral pedicles in rat model. In total, 159 rats were divided into one control and three (primary, secondary, or bilateral pedicle) IP treatment groups. IP was performed on different pedicles by three cycles of 10 minutes of pedicle clamping and 10 minutes of release. After IP procedure secondary pedicle was ligated in all groups, and flaps were exposed to 0, 1, 2, 4, or 6 hours of global ischemia by clamping primary pedicle. In control groups, after the perfusion of bipedicled flaps for 1 hour, left pedicle was ligated and flaps were exposed to global ischemia as in IP groups. On day 5 post‐surgery, tissue samples and topographic measurements were taken. No significant differences in semi‐quantitative scorings of polymorphonuclear leukocytes infiltration, chronic inflammation, interstitial edema, neovascularization, VEGF, and CD105 expression levels among groups were found (P > 0.05). Percentages of necrosis were consistently smaller in IP groups compared to controls for the same duration of global ischemia, with exception of the no‐ischemia. Area of necrosis was significantly smaller in primary IP group versus secondary IP group in the absence of global ischemia (P < 0.01). In the presence of global ischemia, both primary and secondary pedicle IP groups had significantly smaller percentage of necrosis than controls (P < 0.05) and there was no significant difference between primary and secondary IP groups (P > 0.05). Thus, IP performed on different pedicles may ameliorate flap survival in a comparable fashion, depending on the duration of global ischemia. Secondary pedicle IP was as effective as primary pedicle IP and may be feasible in free flap transfers. © 2013 Wiley Periodicals, Inc. Microsurgery 34:129–135, 2014.  相似文献   
40.
In this study, we aimed to compare the success and complications of flexible ureterorenoscopy (F-URS) with its advanced technology and the accomplished method of shock wave lithotripsy (SWL) in the treatment of lower pole stones smaller than 1 cm. One hundred and forty patients were randomized as 70 undergoing SWL (Group 1) and 70 undergoing F-URS (Group 2). Patients were evaluated by plain X-ray and urinary ultrasound 1 week and after 3 months following SWL. The same procedure was done for F-URS patients 1 week after surgery and after 3 months. Success rates were established the day following the procedure and after 3 months. Fragmentation less than 3 mm was considered success. Mean operative time was 44 ± 7.4 min for Group 2 and mean fluoroscopy duration was 51 ± 12 s. In F-URS group, all the patients were stone free after 3 months (100 %). Group 1 had 2.7 ± 0.4 sessions of SWL. Sixty-four patients were stone free in that group after 3 months (91.5 %). The procedure yielded significant success in FURS group, even though patients underwent SWL for 2.7 ± 0.4 sessions and F-URS for 1 session (p < 0.05). With higher success and similar complication rates, fewer sessions per treatment, and advances in technology and experience, we believe F-URS has a potential to be the first treatment option over SWL in the future.  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