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   538篇
  免费   24篇
  国内免费   9篇
耳鼻咽喉   4篇
儿科学   28篇
妇产科学   54篇
基础医学   65篇
口腔科学   28篇
临床医学   41篇
内科学   108篇
皮肤病学   19篇
神经病学   23篇
特种医学   14篇
外科学   102篇
综合类   6篇
预防医学   14篇
眼科学   5篇
药学   47篇
中国医学   2篇
肿瘤学   11篇
  2024年   2篇
  2023年   6篇
  2022年   9篇
  2021年   14篇
  2020年   13篇
  2019年   17篇
  2018年   17篇
  2017年   20篇
  2016年   24篇
  2015年   14篇
  2014年   21篇
  2013年   31篇
  2012年   38篇
  2011年   39篇
  2010年   25篇
  2009年   30篇
  2008年   48篇
  2007年   46篇
  2006年   47篇
  2005年   29篇
  2004年   32篇
  2003年   18篇
  2002年   14篇
  2001年   2篇
  2000年   3篇
  1999年   1篇
  1998年   4篇
  1997年   2篇
  1996年   2篇
  1989年   1篇
  1987年   1篇
  1982年   1篇
排序方式: 共有571条查询结果,搜索用时 0 毫秒
91.
92.
Chronic obstructive pulmonary disease (COPD) is a lung disease characterized with limitation of airflow that is not completely reversible, progressive deterioration of airways and systemic inflammation. This study has been planned to determine daily symptom variability of patients, expectations of patient and physicians from treatment and patient profiles. A total of 514 patients with COPD from 25 centers were included in this national, multicenter, cross-sectional observational study. Data regarding demographic features, concomitant diseases, history and treatment of COPD and expectations of patients and physicians were all obtained in a single visit. Mean [standard deviation (SD)] age of the patients was 64.1 (9.5) years; age range was 41-92 years, 50% of the patients were younger than 65 years and 91% were males. Educational level of the patients was at least primary school in 80.2%; and 54.3% (30.4%) of the patients had at least one concomitant disease, particularly a cardiovascular disease. Mean (SD) duration of having COPD was 5.4 (4.6) years. The majority of patients were at moderate (43.2%) and severe (35.0%) COPD stages and one or more exacerbations per year was determined in 71%. Inhaled beta-2 agonists (84.2%), inhaled steroids (76.3%) and inhaled long-acting anti-cholinergics (70.0%) were the most commonly used medications. Dyspnea (99.0%), sputum production (92.8%) and wheezing (90.5%) were the most common symptoms, and symptom variability for dyspnea (41.1%), sputum production (61.0%) and cough (53.5%) were seen the most in the morning hours (p< 0.001). Most commonly affected morning activity was climbing up/down the stairs (point of effect: 6.7), followed by wearing socks/shoes (point of effect: 4.3) and showering/bathing (point of effect: 4.2) by COPD. Major treatment expectations of patients were greater symptomatic relief (82.3%) and greater mobility (70.0%), faster symptomatic relief (61.1%) and improvement in morning activities (59.3%); while major treatment expectations of physicians included increased quality of life (100.0%) and decreased morbidity (96.0%). Quitting smoking was the most commonly recommended (88.3%) and implemented (67.9%) non-drug protective approach aimed at decreasing the frequency of exacerbations. Consequently, our results demonstrate that COPD is not a disease of only the elderly, is an important healthcare issue that often disrupt daily living of the patients due to inadequate disease awareness leading to overlooking of the symptoms by patient and physicians, and that a patient-centered approach based on the living standards, life expectancies and preferences of patients was crucial in patient management.  相似文献   
93.
94.
95.
96.
Background: Cytokines are essential mediators of immune response. Chronic renal failure patients suffer from chronic inflammation that results from factors such as impaired renal function, accumulation of uremic toxins and bio incompatibility of dialyzer membranes. These patients are also at increased risk of cardiovascular diseases. We have evaluated cytokines, adipocytokines and inflammatory markers in patients with chronic renal failure undergoing hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD).

Material and methods: We have determined serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), leptin and ghrelin levels of chronic renal failure patients treated with either HD (n?=?20) or CAPD (n?=?20). TNF-α, IL-6, ghrelin and leptin measurements were performed by commercially available kits based on enzyme-linked immunosorbent assay (ELISA) method. hsCRP levels were determined by turbidimetric methods.

Results: Serum TNF-α and IL-6 levels of patients on HD were significantly higher than those of the ones on CAPD (p?<?0.05). Ghrelin, leptin and hsCRP concentrations were similar in both groups.

Conclusions: We can conclude that cytokine production is more obvious in HD process.  相似文献   
97.
Abstract: The present study was conducted to investigate the possible protective effects of lycopene (LP) and ellagic acid (EA) on aroclor (AR) 1254‐induced testicular and spermatozoal toxicity associated with the oxidative stress and apoptosis in male rats. The control group was treated with placebo. LP (10 mg/kg/every other day), EA (2 mg/kg/every other day) and AR (2 mg/kg/day) groups were given alone LP, EA and AR respectively. One of the last two groups received AR + LP, and the other treated with AR + EA. Body and reproductive organ weights, epididymal sperm characteristics, testicular tissue lipid peroxidation levels, antioxidant enzyme activities, histopathological changes and apoptosis via Bax and Bcl‐2 genes were investigated. AR administration caused statistically significant decreases in body‐weight, epididymal sperm concentration, testicular superoxide dismutase activity, diameters of seminiferous tubules, germinal cell layer thickness and Johnsen’s testicular score, and increases in relative weights of testis, epidydimis and seminal vesicles, rates of abnormal sperm and apoptotic cell expression along with degeneration, desquamation and disorganization in spermatogenic cells, and interstitial oedema and congestion in testicular tissue. LP and EA treatments to AR‐treated rats markedly decreased abnormal sperm rates, testicular thiobarbituric acid reactive substances level, and increased the glutathione (GSH) level, GSH‐peroxidase, catalase activities and epidiymal sperm concentration as compared with the alone AR group. Additionally, the AR‐induced histopathological damages were totally or partially recovered by LP or EA administrations respectively. AR damages the testicular tissue and spermatozoa by impairing the oxidant/antioxidant balance and by increasing the apoptotic spermatogenic cell rates. However, both LP and EA have modulator effects on AR‐induced reproductive dysfunction in male rats.  相似文献   
98.
IntroductionClitoral blood flow measurements using clitoral color Doppler ultrasound have been performed with increasing frequency either in order to assessment of female sexual function/dysfunction. The trials to evaluate the sexual function in healthy subjects, especially in the subgroup of female elite athletes, are limited.AimThe aim of the study was to evaluate whether elite female athletes and sedentary healthy females differ in their clitoral blood flow and sexual function as an expression of their physical fitness status.MethodsTwenty-five female elite athletes (Group I) and healthy female subjects (Group II) were enrolled as volunteers in the study. All women were instructed to complete the Female Sexual Function Index (FSFI) questionnaire. Each subject underwent high definition color Doppler ultrasonography to measure the clitoral blood flow parameters.Main Outcome MeasuresThe effect of physical activity on clitoral blood flow and sexual life in women.ResultsMean age, mean age of menarche, mean marriage age, and body mass index were similar for both groups. In Group I, the mean peak systolic velocity and end-diastolic velocity were higher than those of Group II, whereas the mean RI was similar for both groups. There were statistically significant differences for total FSFI score and all domain scores, except desire domain, between both groups.ConclusionIn elite female athletes as compared with sedentary healthy females, better clitoral blood flow and better sexual function were demonstrated. Therefore it seems superior physical fitness correlates with better sexual function. Karatas OF, Baltaci G, Ilerisoy Z, Bayrak O, Cimentepe E, Irmak R, and Unal D. The evaluation of clitoral blood flow and sexual function in elite female athletes.  相似文献   
99.
100.
Epigallocatechin gallate (EGCG), is the most abundant and widely studied catechin in green tea (Camellia sinensis Theaceae). The inhibitory effects of EGCG and green tea extract on carcinogenesis in various organs in rodents have now been demonstrated over the past decade. The aim of study was to label EGCG with I-131, to determinate its structure and to evaluate its biodistribution in Wistar rats. Radiolabeling was carried out by direct electrophilic iodination method (iodogen) and yield was determined by radio thin layer chromatography (RTLC). Radiolabelling yield is determined as 89 ± 1.0%. Besides, determination of structure of iodinated molecule, serum stability, and partition coefficient experiments was performed. The structure analysis of synthesized cold 127I-EGCG complex was assessed with LC–MS–MS and 1H-NMR. 1H-NMR and LC–MS–MS results of iodinated EGCG (127I-EGCG) show that oxidize iodine reacts electrophilic with aromatic ring. Serum stability results showed that in vitro stability of 131I-EGCG was quite high. It is observed that labeling percentage decreased 83 ± 2% at 24th, Partition coefficient results show that the partition coefficient of EGCG was calculated as theoretical partition coefficient = 2.04 ± 0.42 and the experimental partition coefficient of 131I-EGCG was found as 1.46 ± 0.2. The biodistribution data shown that the maximum uptake of the radioiodinated EGCG was seen in lung and pancreas at 30 min. The blocking assay results indicated that the uptake of 131I-EGCG in lung was not significantly change (0.25, 0.23, and 0.22%ID/g at 30, 60, and 150 min, respectively). Biodistribution data showed no significant uptake in a specific organ of the rat. Hence radiolabeled EGCG is seen in some organs (lung, liver, pancreas, kidney, etc.).  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