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   282篇
  免费   9篇
  国内免费   4篇
耳鼻咽喉   11篇
儿科学   22篇
妇产科学   1篇
基础医学   11篇
口腔科学   8篇
临床医学   16篇
内科学   46篇
皮肤病学   3篇
神经病学   40篇
特种医学   11篇
外科学   92篇
综合类   1篇
预防医学   7篇
眼科学   4篇
药学   5篇
肿瘤学   17篇
  2024年   1篇
  2023年   5篇
  2022年   6篇
  2021年   9篇
  2020年   2篇
  2019年   5篇
  2018年   6篇
  2017年   5篇
  2016年   6篇
  2015年   15篇
  2014年   9篇
  2013年   19篇
  2012年   17篇
  2011年   14篇
  2010年   10篇
  2009年   10篇
  2008年   10篇
  2007年   10篇
  2006年   25篇
  2005年   23篇
  2004年   27篇
  2003年   25篇
  2002年   17篇
  2001年   5篇
  2000年   2篇
  1998年   3篇
  1997年   3篇
  1996年   1篇
  1995年   2篇
  1993年   2篇
  1992年   1篇
排序方式: 共有295条查询结果,搜索用时 31 毫秒
1.
OBJECTIVE: We aimed to demonstrate the time-dependent ultrastructural changes in pneumocyte type II cells following brain injury, and to propose an electron microscopic scoring model for the damage. METHODS: Forty Wistar-Albino female rats weighing 170-200 g were used. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The others were trauma groups. Weight-drop method was used for achieving head trauma. Samples were obtained from the right and left pulmonary lobes at 2-, 8-, and 24-h intervals after transcardiac perfusion. An electron microscopic scoring model was used to reveal the changes. RESULTS: There were no ultrastructural pathological findings pointing to lung injury in any rat of the control groups. There was intense intracellular oedema in type II pneumocyte and interstitial oedema in the adjacent tissue in trauma groups. Oedema in mitochondria and dilatation in both smooth endoplasmic reticulum and Golgi apparatus was more evident in the 8- and 24-h trauma groups. The chromatin dispersion was disintegrated in the nucleus in all trauma groups. Scores of all trauma groups were significantly different from the controls (P<0.05). All trauma groups were different from each other at significant levels (P<0.05 for each trauma groups). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 h and deteriorates with time. The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation. Further experiments are needed to determine the exact outcome after brain death model.  相似文献   
2.
In patients with uncomplicated idiopathic hypercalciuria renal function is normal except for increased renal calcium excretion. In this study, the level of fractional urinary enzyme excretion was assessed in relation to calciuria. Fourteen patients with a mean age of 5.8 +/- 0.8 years who had daily urinary calcium excretion more than 4 mg/kg and with otherwise normal renal function tests were included in the study. None of the patients manifested either renal calculus or nephrocalcinosis. Fourteen normal children with a mean age of 5.4 +/- 0.74 were included in the control group. The level of the urinary N-acetyl beta-D glucosaminidase (NAG) to creatinine ratio, fractional aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) excretion were not significantly different compared to the control group (p > 0.05). The patients were subdivided according to the type of hypercalciuria. The levels of NAG/creatinine ratio, fractional ALT, AST, ALP, LDH excretion were not significantly different in the absorptive type of calciuria group compared to the control group (p > 0.05). In conclusion, hypercalciuria during childhood which is 6.46 +/- 1.83 mg/kg/day is not related to the levels of NAG/creatinine ratio, fractional ALT, AST, ALP and LDH excretion in urine.  相似文献   
3.
We aimed to determine the diagnostic performance of the contrast‐enhanced fat‐suppression technique in the detectability of perianal infections and to compare this technique with different MR sequences used for this purpose. Thirty consecutive patients with clinically suspected anorectal infections were examined with fast spin‐echo (FSE) T2‐weighted, short‐inversion‐time inversion recovery (STIR), and fat‐suppressed and non‐fat‐suppressed T1‐weighted spoiled gradient‐echo (SGE) (in‐phase) dynamic contrast‐enhanced sequences. The results of MRI were correlated with the findings of surgery, which was considered as the standard of reference. Receiver‐operating‐characteristic curves were reconstructed to describe and compare the diagnostic value of each MR technique. The values of kappa were used as a measure of observer reliability. Diagnostic performances of STIR, FSE T2‐weighted and fat‐suppressed and non‐fat‐suppressed, contrast‐enhanced SGE T1‐weighted techniques showed statistically insignificant differences in detection of perianal infections. There was almost perfect interobserver agreement regarding the presence of lesions on each MR technique. Fat‐suppressed, contrast‐enhanced SGE T1‐weighted MRI showed adequate diagnostic performance in the detection of perianal infections. However, its significance is not different from the other MR sequences used for the present study.  相似文献   
4.
OBJECTIVE—To evaluate the role of vitamin A on renal scarring in recurrent urinary tract infections (UTIs).
DESIGN—Twenty three children with UTIs and renal scarring (mean (SD) age 7.3 (3.9) years) and 91 children without renal scarring (6.4 (3.4) years) were studied. All the children had serum vitamin A and β-carotene measurements and nutritional evaluation. Renal scarring was assessed by technetium-99m dimercaptosuccinic acid (99mTc DMSA) scanning. Nutritional status of all the patients was within normal limits and not different between the groups.
RESULTS—Mean (SD) serum vitamin A and β-carotene concentrations were not significantly different between the patients with and without renal scarring (vitamin A 53.2 (22.6)/46.8 (17.0) µg/dl and β-carotene 232.3 (201.3)/272.4 (86.0) µg/dl respectively). However, when the patients with renal scarring and with greater than 10% difference among the DMSA uptakes of their kidneys (11 cases) were evaluated, a significant negative correlation was determined between the serum vitamin A concentrations and the magnitude of the difference in uptakes of each kidney. The same relation was not true for serum β-carotene concentrations.
CONCLUSION—This study demonstrated a relation between serum vitamin A concentrations and magnitude of hypoactivity in 99mTc DMSA scanning in kidneys with advanced scarring.

  相似文献   
5.
Abstract Background : The aim of the present study was to determine the prevalence, associated symptoms, and clinical outcomes of children with acute abdominal pain who had been admitted to an emergency department. Methods : Children aged between 2 and 16 years who presented to the emergency department of Cerrahpa?a Medical School, Istanbul University between July 2001 and August 2002 with acute abdominal pain were enrolled in this study. A questionnaire was completed each patient admitted to our pediatric emergency unit for acute abdominal pain. Data collected included presenting signs and symptoms, the hospital follow up for all children who returned within 10 days, test results, and telephone follow up. Results : The number of children referred to the emergency department was 7442, with 399 (5.4%) of these having acute abdominal pain. The mean age of the study population was 6.9 ± 3.5 years, and 201 of the patients were male. The five most prevalent diagnoses were: (i) upper respiratory tract infection and/or complicated with otitis media or sinusitis (23.7%); (ii) abdominal pain with uncertain etiology (15.4%); (iii) gastroenteritis (15.4%); (iv) constipation (9.4%); and (v) urinary tract infection (8%). The most common associated symptoms were decreased appetite, fever and emesis. Because of follow‐up deficiency the progress of 28 patients was not obtained. Eighty‐two children were referred to the department of pediatric surgery, but only 17 of 82 (20.7%) required surgical intervention (15 of these 17 for appendicitis). Eleven patients returned within 10 days for re‐evaluation, but the initial diagnosis was not changed. The complaints of 57 patients with uncertain etiology were resolved within 2 days. Conclusions : An acute complaint of abdominal pain was usually attributed to a self‐limited disease. However, the percentage of surgical etiology is not negligible.  相似文献   
6.
7.
8.

Background:

Vesicoureteral reflux (VUR) is a common abnormality of the urinary tract in childhood.

Objectives:

As urine enters the ureters and renal pelvis during voiding in vesicoureteral reflux (VUR), we hypothesized that change in body water composition before and after voiding may be less different in children with VUR.

Patients and Methods:

Patients were grouped as those with VUR (Group 1) and without VUR (Group 2). Bioelectric impedance analysis was performed before and after voiding, and third space fluid (TSF) (L), percent of total body fluid (TBF%), extracellular fluid (ECF%), and intracellular fluid (ICF%) were recorded. After change of TSF, TBF, ECF, ICF (ΔTSF, ΔTBF%, ΔECF%, ΔICF%), urine volume (mL), and urine volume/body weight (mL/kg) were calculated. Groups 1 and 2 were compared for these parameters. In addition, pre- and post-voiding body fluid values were compared in each group.

Results:

TBF%, ECF%, ICF%, and TSF in both pre- and post-voiding states and ΔTBF%, ΔECF%, ΔICF%, and ΔTSF after voiding were not different between groups. However, while post-voiding TBF%, ECF% was significantly decreased in Group 1 (64.5 ± 8.1 vs 63.7 ± 7.2, P = 0.013 for TBF%), there was not post-voiding change in TSF in the same group. On the other hand, there was also a significant TSF decrease in Group 2.

Conclusions:

Bladder and ureter can be considered as the third space. Thus, we think that BIA has been useful in discriminating children with VUR as there was no decreased in patients with VUR, although there was decreased TSF in patients without VUR. However, further studies are needed to increase the accuracy of this hypothesis.  相似文献   
9.

Background:

As a zoonotic pathogen, Encephalitozoon cuniculi is a cause of serious disease in animals and people. The present study was to evaluate the health status examination of this seropositive animal care worker in our previous study.

Methods:

Blood samples were taken from five workers. CIA test was applied to detect antibodies against E. cuniculi in blood serum. The indirect immunofluorescence antibody test was used as confirmation test. Seropositive worker had a complete medical examination.

Results:

Only one worker was found to be seropositive according to the results of the serological test. Sera positive to E. cuniculi was confirmed with IFAT and spores were detected in the urine sample of the worker. The worker was treated with albendazole.

Conclusion:

Rabbits should be examined routinely for the presence of anti-E. cuniculi antibody. People working with laboratory animal should avoid contact with urine and faeces of infected or pay attention to personal hygiene.  相似文献   
10.
Objective: The majority of patients with chronic noncancer pain (CNCP) are managed in the primary care settings. The primary care family physician (PCFP) generally has limited time, training, or access to resources to effectively evaluate and treat these patients, particularly when there is the added potential liability of prescribing opioids. The aim of this study is to make a favorable change in PCFPs’ knowledge, attitudes, and practices about opioid use in CNCP via education on assessment of the risk of opioid misuse. Materials and methods: The universe of this cross-sectional study comprised 36 family physicians working at Family Health Centers affiliated to Antalya Provincial Directorate of Health who volunteered to participate in the study. Initially, a survey on patients risk assessment was performed in both intervention and control groups; whereas the intervention group received education on assessment of the risk of opioid misuse, the control group did not. The survey was repeated after 6 months and the intervention group underwent a core examination. Data obtained were analyzed with Statistical Package for the Social Sciences 18.0 statistics program. Intervention and control groups were compared. Additionally, pre- and post-education results of the intervention group were also compared. Results: About 61.1% of family physicians reported concern and hesitation in prescribing opioids due to known risks, such as overdose, addiction, dependence, or diversion, and agreed that family physicians should apply risk assessment before opioid use in CNCP. Only 16.6% of PCFP reported that risk assessment is not so necessary, whereas 22.2% of PCFP were undecided. Although 47.2% of the family physicians expressed a willingness to apply risk assessment before starting opioids, the rate of eagerness increased markedly to 77.7% after the education, but the rate of increase in practicing was not statistically significant. Conclusion: Knowledge and competency of the family physicians in managing CNCP were improved as was expected. Although the rate of eagerness about risk assessment of opioid misuse was increased, expected increase in the rate of using risk assessment was not achieved. Further studies are needed to identify the reasons of the difficulties on changing the attitudes and practices of primary care physicians about this subject.  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