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   351篇
  免费   10篇
耳鼻咽喉   4篇
儿科学   14篇
妇产科学   4篇
基础医学   33篇
口腔科学   6篇
临床医学   36篇
内科学   66篇
皮肤病学   7篇
神经病学   11篇
特种医学   49篇
外科学   72篇
综合类   7篇
预防医学   19篇
眼科学   1篇
药学   14篇
肿瘤学   18篇
  2023年   3篇
  2022年   2篇
  2021年   14篇
  2020年   13篇
  2019年   9篇
  2018年   13篇
  2017年   8篇
  2016年   6篇
  2015年   5篇
  2014年   9篇
  2013年   18篇
  2012年   33篇
  2011年   25篇
  2010年   14篇
  2009年   13篇
  2008年   31篇
  2007年   24篇
  2006年   19篇
  2005年   21篇
  2004年   14篇
  2003年   17篇
  2002年   10篇
  2001年   5篇
  2000年   4篇
  1999年   4篇
  1998年   3篇
  1996年   4篇
  1994年   1篇
  1993年   1篇
  1992年   5篇
  1991年   4篇
  1989年   1篇
  1985年   1篇
  1984年   2篇
  1982年   3篇
  1979年   2篇
排序方式: 共有361条查询结果,搜索用时 15 毫秒
11.
Background The return of olfaction and of sinonasal function are important end points after pituitary surgery. Opinions differ on the impact of surgery because techniques vary greatly. A modified preservation of the so-called olfactory strip is described that utilizes a small nasoseptal flap and wide exposure. Methods A cohort of patients undergoing pituitary surgery and endoscopic sinonasal tumor surgery were assessed. Patient-reported outcomes (Sino-Nasal Outcome Test [SNOT22] and Nasal Symptom Score [NSS]) were recorded. A global score of sinonasal function and the impact on smell and taste were obtained. Objective smell discrimination testing was performed in the pituitary group with the Smell Identification Test. Outcomes were assessed at baseline and at 6 months. Results Ninety-eight patients, n = 40 pituitary (50.95 ± 15.31 years; 47.5% female) and n = 58 tumor (52.35 ± 18.51 years; 52.5% female) were assessed. For pituitary patients, NSSs were not significantly different pre- and postsurgery (2.75 ± 3.40 versus 3.05 ± 3.03; p = 0.53). SNOT22 scores improved postsurgery (1.02 ± 0.80 versus 0.83 ± 0.70; p = 0.046). Objective smell discrimination scores between baseline and 6 months were similar (31.63 ± 3.49 versus 31.35 ± 4.61; p = 0.68). No difference in change of olfaction was seen compared with controls (Kendall tau-b p = 0.46). Conclusions Preservation of the olfactory strip can provide a low morbidity approach without adversely affecting olfaction and maintaining reconstruction options.  相似文献   
12.
13.
Cardiovascular problems are a major cause of morbidity and mortality in patients with autosomal dominant polycystic kidney disease (ADPKD). Endothelial dysfunction (ED), which is an early manifestation of vascular injury, has been shown in patients with ADPKD. Statins have a beneficial effect in the reversal of ED. The aim of this study was to investigate the effects of a statin, simvastatin, on ED in patients with ADPKD. Sixteen patients with ADPKD having well-preserved renal function were included in the study. Endothelial function of the brachial artery was evaluated by using high-resolution vascular ultrasound. Endothelial-dependent dilatation (EDD) was expressed as the percentage change in the brachial artery diameter from baseline to reactive hyperemia. After the baseline evaluations of EDDs, patients were started treatment with simvastatin at a dose of 40 mg/day and were treated for six months. EDDs were recalculated after one and six months of therapy. Interleukin-6 (IL-6) and high-sensitivity C-reactive protein were also measured as markers of inflammation. Baseline EDD was 11.3 ± 6.9% in patients with ADPKD. After one month of simvastatin treatment, EDD increased significantly to 14.6 ± 4.6 % (P = 0.016 versus baseline). Endothelial-dependent dilatation further increased significantly to 18.9 ± 7.5 % (P = 0.011 versus baseline, P = 0.048 versus first month) after six months of therapy. There was also a significant decrease in the level of IL-6 from 21.6 ± 21.7 pg/mL to 9.1 ± 3.5 pg/mL (P= 0.002).

Six months of simvastatin therapy resulted in a significant improvement of ED in patients with ADPKD. This finding may be in part related to the pleiotropic effects of simvastatin.  相似文献   
14.
15.
Pneumothoraces are a possible sequela of chest trauma with potential morbidity and mortality if not recognized and treated promptly. A portable supine chest radiograph is frequently the first radiologic study performed in the setting of trauma. While large pneumothoraces can be readily recognized on these radiographs, smaller pneumothoraces are missed in up to 15 % of trauma patients. There are many radiographic signs of occult pneumothoraces, and we are presenting a new radiographic sign of occult pneumothorax. The floating cardiac fat pad sign occurs when pleural air collects anteriorly and superiorly in the most non-dependent portion of the chest lifting the pericardial fat pad off the diaphragm. Lung markings are still seen surrounding the pericardial fat pad due to the inflated lower lobe of the lung resting dependently. Rapid and accurate identification of pneumothoraces is critical but often difficult on chest radiographs. Although there are many existing radiographic signs for identification of pneumothorax, prospective identification of small pneumothoraces is still relatively poor. Here, we describe an additional sign which aides in the detection of pneumothoraces, the floating cardiac fat pad. When present, this should prompt further evaluation with chest CT or upright chest radiograph.  相似文献   
16.
Cultured cells are dramatically affected by the micro-environment in which they are grown. In this study, we have investigated whether HepG2 liver cells grown in three dimensional (3-D) cultures cope more effectively with the known cytotoxic agent, methotrexate, than their counterparts grown on traditional two dimensional (2-D) flat plastic surfaces. To enable 3-D growth of HepG2 cells in vitro, we cultured cells on 3-D porous polystyrene scaffolds previously developed in our laboratories. HepG2 cells grown in 3-D displayed excellent morphological characteristics and formed numerous bile canaliculi that were seldom seen in cultures grown on 2-D surfaces. The function of liver cells grown on 3-D supports was significantly enhanced compared to activity of cells grown on 2-D standard plasticware. Unlike their 2-D counterparts, 3-D cultures were less susceptible to lower concentrations of methotrexate. Cells grown in 3-D maintained their structural integrity, possessed greater viability, were less susceptible to cell death at higher levels of the cytotoxin compared to 2-D cultures, and appeared to respond to the drug in a manner more comparable to its known activity in vivo. Our results suggest that hepatotoxicity testing using 3-D cultures might be more likely to reflect true physiological responses to cytotoxic compounds than existing models that rely on 2-D culture systems. This technology has potential applications for toxicity testing and drug screening.  相似文献   
17.
Introduction

Obesity is associated with increased morbidity and mortality in abdominal trauma patients. The characteristics of abdominal trauma patients with poor outcomes related to obesity require evaluation. We hypothesize that obesity is related to increased mortality and length of stay (LOS) among abdominal trauma patients undergoing laparotomies.

Methods

Abdominal trauma patients were identified from the National Trauma Data Bank between 2013 and 2015. Patients who received laparotomies were analyzed using propensity score matching (PSM) to evaluate the mortality rate and LOS between obese and non-obese patients. Patients without laparotomies were analyzed as a control group using PSM cohort analysis.

Results

A total of 33,798 abdominal trauma patients were evaluated, 10,987 of them received laparotomies. Of these patients, the proportion of obesity in deceased patients was significantly higher when compared to the survivors (33.1% vs. 26.2%, p < 0.001). Elevation of one kg/m2 of body mass index independently resulted in 2.5% increased odds of mortality. After a well-balanced PSM, obese patients undergoing laparotomies had significantly higher mortality rates [3.7% vs. 2.4%, standardized difference (SD) = 0.241], longer hospital LOS (11.1 vs. 9.6 days, SD = 0.135), and longer intensive care unit LOS (3.5 vs. 2.3 days, SD = 0.171) than non-obese patients undergoing laparotomies.

Conclusions

Obesity is associated with increased mortality in abdominal trauma patients who received laparotomies versus those who did not. Obesity requires a careful evaluation of alternatives to laparotomy in injured patients.

  相似文献   
18.
The simultaneous occurrence of colorectal malignancy with pelvic kidney is unusual. We report a case of locally advanced rectal cancer stage III disease, T3N2M0, with a pelvic kidney complicating adjuvant radiation therapy. We recommend preoperative evaluation of the pelvic kidney to allow for its protection by translocation or heterotopic autologous transplantation. Occasionally a nephrectomy may be necessary. Otherwise extended lymph node dissection is not performed; hence, adequate treatment of the primary rectal cancer is compromised. The sequela of inadequate surgical excision and suboptimal radiation therapy is early relapse. © 1996 Wiley-Liss, Inc.  相似文献   
19.
20.
OBJECTIVE: To provide a national profile of the area variation in per-capita psychostimulant consumption in the U.S. METHODS: We separated 3030 U.S. counties into two categories of 'low' and 'high' per-capita use of attention deficit hyperactivity disorder (ADHD) drugs (based on data from the Drug Enforcement Administration), and then analyzed them on the basis of their socio-demographic, economic, educational and medical characteristics. RESULTS: We found significant differences and similarities in the profile of counties in the U.S. that are above and below the national median rate of per-capita psychostimulant use (defined as g/per 100K population). Compared to counties below the median level, counties above the median level have: significantly greater population, higher per-capita income, lower unemployment rates, greater HMO penetration, more physicians per capita, a higher ratio of young-to-old physicians and a slightly higher students-to-teacher ratio. CONCLUSIONS: Our analysis of the DEA's ARCOS data shows that most of the significant variables correlated with 'higher' per-capita use of ADHD drugs serve as a proxy for county affluence. To provide a more complex, multivariate analysis of the area variation in psychostimulant use across the U.S.-which is the logical next step-requires obtaining price data to match the DEA's quantity data.  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