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   1503篇
  免费   97篇
  国内免费   14篇
耳鼻咽喉   37篇
儿科学   56篇
妇产科学   55篇
基础医学   121篇
口腔科学   89篇
临床医学   180篇
内科学   356篇
皮肤病学   56篇
神经病学   161篇
特种医学   88篇
外科学   160篇
综合类   15篇
一般理论   1篇
预防医学   67篇
眼科学   56篇
药学   58篇
中国医学   1篇
肿瘤学   57篇
  2024年   1篇
  2023年   26篇
  2022年   34篇
  2021年   58篇
  2020年   50篇
  2019年   61篇
  2018年   58篇
  2017年   65篇
  2016年   65篇
  2015年   76篇
  2014年   80篇
  2013年   105篇
  2012年   129篇
  2011年   115篇
  2010年   54篇
  2009年   64篇
  2008年   115篇
  2007年   108篇
  2006年   89篇
  2005年   98篇
  2004年   74篇
  2003年   49篇
  2002年   19篇
  2001年   6篇
  2000年   1篇
  1999年   4篇
  1998年   3篇
  1997年   2篇
  1996年   4篇
  1986年   1篇
排序方式: 共有1614条查询结果,搜索用时 0 毫秒
1.
BACKGROUND: Atherosclerotic vascular diseases are the major cause of mortality in patients with end-stage renal disease (ESRD) treated with chronic peritoneal dialysis (CPD), even in children. Adiponectin (ADPN) is a recently discovered adipocyte-derived plasma protein having anti-atherogenic properties. ADPN levels are elevated in ESRD but it has been reported that ESRD patients with low plasma ADPN levels have a high risk of cardiovascular death. OBJECTIVE: To clarify the atherosclerotic risk and especially the significance of ADPN levels in pediatric patients on CPD. DESIGN: Cross-sectional studyin the pediatric peritoneal dialysis unit of a university hospital. PATIENTS: 18 children, aged 12.6 +/- 5.6 years, being treated with CPD and 20 healthy age- and sex-matched control subjects were enrolled in this study. METHODS: Serum ADPN levels and other risk factors, including blood pressure, blood glucose, serum lipid/lipoprotein fractions, apolipoprotein B, C-reactive protein (CRP), lipoprotein(a), and homocysteine levels, were studied in CPD patients and compared to the controls. RESULTS: Serum ADPN levels were three times higher in the CPD group compared to the control subjects, as was previously reported. Apolipoprotein B and CRP levels were also high in the CPD group. No significant difference was found in other atherosclerotic parameters, including lipoprotein(a) and homocysteine levels. Interestingly, we found a negative correlation between log ADPN and creatinine levels among the CPD patients (r = -0.54, p < 0.05). There was no correlation between log ADPN and duration of CPD. Creatinine and low-density lipoprotein levels could account for 54% of the total variation in ADPN levels. CONCLUSION: Among pediatric CPD patients, serum levels of the anti-atherogenic protein, ADPN, were inversely associated with creatinine. ADPN level might be a novel marker to predict prognosis in pediatric CPD patients.  相似文献   
2.
The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro-ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane.  相似文献   
3.
Background:Nutritional habits of patients with functional dyspepsia can affect the progression of functional dyspepsia. We aimed to determine the foods and dietary habits that may cause symptoms of postprandial fullness, early satiety, epigastric pain, and epigastric burning in functional dyspepsia patients.Methods:Sixty functional dyspepsia patients, who were diagnosed according to Rome IV criteria in the endoscopy unit of a gastroenterology institute, were included in the study. Data on the demographic characteristics, anthropometric measurements, nutritional habits, and food consumption frequency questionnaire of functional dyspepsia patients were collected.Results:Postprandial fullness was found more common in those who preferred roasting as a cooking method. There was no significant difference between symptoms and meal frequency. Epigastric burning and pain were found to be more pronounced in women, and alcohol consumption was less in patients who experienced more epigastric pain. In non-smoker participants, the complaint of early satiety was lower. It was found that broccoli, radish, celery, green olives, and olive oil consumption was less in participants who experienced excessive postprandial fullness. Patients with stomach pain consumed less dry fruits, green olives, butter, alcohol, and fast food. It was found that patients with stomach burning consumed less alcohol and fast food.Conclusion:In conclusion, functional dyspepsia patients should avoid or reduce consuming broccoli, radish, celery, green olives, olive oil, dry fruits, and butter which may trigger symptoms. Reducing consumption of these foods, abandoning unhealthy cooking methods such as roasting, reducing smoking, and reducing consumption of alcohol and fast food might be beneficial for relieving symptoms.  相似文献   
4.
5.
6.
Chronic viral hepatitis is the main cause of chronic liver disease, cirrhosis and hepatocellular carcinoma throughout the world. Hepatitis B virus (HBV) has mutagenic effects on somatic cells. HBV may be showing these mutagenic effects through its viral proteins or through integrating into host DNA. The aim of this study was to determine whether HBV has a genotoxic effect on host DNA or not. Peripheral blood lymphocytes of 31 chronic HBV patients and 20 chronic HBV carriers were cultured in order to make cytogenetic evaluation by observing chromosome breakage and cytological evaluation by the micronucleus (MN) test. Their results were compared with 20 healthy controls. For each individual, 100 metaphase chromosome spreads were analysed. Around 190-1091 binucleated cells were observed and MN were scored for each individual. Our results showed significantly higher frequencies of chromosome breaks in chronic HBV patients and in HBV carriers than in the control group. There was no difference in MN scores among HBV patients, HBV carriers and healthy carriers. Based on our data, we conclude that chronic HBV patients and carriers have chromosomal instability and that HBV carriers are as affected as patients because of their same chromosome breakage levels.  相似文献   
7.
High prevalence of diabetes in Adana, a southern province of Turkey   总被引:3,自引:0,他引:3  
OBJECTIVE: To determine the prevalence of diabetes and glucose intolerance and their relationship with risk factors in Adana, a southern province of Turkey, where risk factors are more prominent, probably because of social and economic reasons. RESEARCH DESIGN AND METHODS: The study population included 1637 randomly selected adults aged 20-79 years. Diagnosis of diabetes was based on plasma glucose values using the 1999 diagnostic criteria recommended by the World Health Organization. RESULTS: The crude prevalence of diabetes was 12.9% in men and 10.9% in women (P = 0.207). Total prevalence of diabetes was 11.6%. The screening process identified previously undiagnosed diabetes in 4.2% of individuals and impaired glucose homeostasis (consisting of impaired glucose tolerance and impaired fasting glucose) in an additional 4.3% of subjects. The prevalence of hypertension was 26.4% among men and 36.6% among women (P < 0.0001). Total prevalence of hypertension was 32.9%, and prevalence of obesity was 43.4%. Age, sex, BMI, waist circumference, hypertension, family history of diabetes, and triglycerides were independently associated with diabetes. CONCLUSIONS: The prevalence of diabetes in Adana is higher than expected in both urban and rural areas. Obesity and hypertension also seem to be common metabolic disorders in this area. Age, hypertension, obesity, high triglyceride level, and family history of diabetes are independently associated with diabetes. Therefore, primary prevention through lifestyle modifications may have a critical role in the control of diabetes.  相似文献   
8.
Background: The exact etiology of irritable bowel syndrome (IBS) remains unclear. Curative treatment is not available and current treatment modalities are mainly directed against the predominant symptoms. There are a few studies reporting the beneficial effects of transcutaneous electrical stimulation in patients with chronic constipation, gastroparesis, and functional dyspepsia. Aim: To investigate whether transcutaneous electrical stimulation is an effective procedure in IBS patients. Methods: IBS patients were randomly placed in vacuum interferential current (IFC) and placebo groups. Both treatments consisted of 12 sessions administered over 4 weeks. Symptoms due to IBS were documented via questionnaires, including the IBS Global Assessment of Improvement Scale, numeric rating scales, visual analogue scale, and IBS Quality of Life Scale at the beginning of, end of, and 1 month after the treatment. Results: Patients in the therapy (29 cases) and placebo (29 cases) groups were homogeneous with respect to demographic data and gastrointestinal system symptoms. When compared to the beginning scores, severity of abdominal discomfort, bloating, and abdominal distension and rumbling improved significantly in either interference or placebo groups at both the end of treatment and 1 month after treatment. In the IFC group, severity of symptoms continued to decrease significantly at 1 month after treatment when compared to scores at just the end of treatment, whereas in the placebo group severity of these symptoms did not change significantly on numeric severity scales. Also, the visual analogue scale of the first month after treatment continued to decrease significantly when compared to the level at the end of treatment in the IFC group. Total quality score increased significantly in the IFC group. Conclusions: Vacuum IFC therapy can significantly improve symptoms and quality of life in patients with IBS. It may represent a novel treatment modality for drug-refractory IBS patients.  相似文献   
9.
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