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   696篇
  免费   31篇
  国内免费   4篇
耳鼻咽喉   66篇
儿科学   20篇
妇产科学   21篇
基础医学   45篇
口腔科学   14篇
临床医学   45篇
内科学   185篇
皮肤病学   11篇
神经病学   39篇
特种医学   48篇
外科学   146篇
综合类   14篇
预防医学   11篇
眼科学   7篇
药学   25篇
肿瘤学   34篇
  2024年   2篇
  2023年   3篇
  2022年   8篇
  2021年   15篇
  2020年   9篇
  2019年   12篇
  2018年   14篇
  2017年   15篇
  2016年   21篇
  2015年   26篇
  2014年   24篇
  2013年   39篇
  2012年   49篇
  2011年   27篇
  2010年   28篇
  2009年   28篇
  2008年   37篇
  2007年   60篇
  2006年   70篇
  2005年   50篇
  2004年   54篇
  2003年   44篇
  2002年   45篇
  2001年   9篇
  2000年   7篇
  1999年   5篇
  1998年   3篇
  1997年   5篇
  1996年   3篇
  1995年   3篇
  1993年   1篇
  1987年   1篇
  1984年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1975年   1篇
  1974年   4篇
  1972年   1篇
  1971年   1篇
  1961年   2篇
  1935年   1篇
排序方式: 共有731条查询结果,搜索用时 15 毫秒
101.
102.
Background & aimsAcute pancreatitis (AP) varies from mild to severe necrotizing changes with high mortality. The objective of the current study was to investigate the effects of curcumin on tissue injury and proinflammatory cytokines in the early and late phases of AP.MethodsAP was induced by sodium taurocholate in rats (n = 140). First group was left untreated. Group II received 100 mg/kg curcumin daily starting 20 days before AP induction. The rats were allocated into 7 sub-groups (n:5) and were sacrificed at 2, 6, 12, 24, 72, 144 and 288 h following the induction of AP. Blood and pancreatic tissue samples were collected for biochemical and histopathologic evaluations and the assessment of protein and mRNA levels, as well.ResultsCurcumin decreased total histopathologic scores in comparison with those of the taurocholate group (P < 0.05). Curcumin increased Caspase-3 activity and decreased trypsin activity, while inhibited nuclear factor-κ (NF-κB) at all time points (P < 0.05) and moreover reduced activator protein-1 (AP-1). Curcumin decreased chemokine (except for 288 h), TNF-α (except for 2 and 24 h), IL-6 (except for 2, 6 and 288 h) and iNOS (except for 144 and 288 h) mRNA levels (P < 0.05). Curcumin serum nitric oxide (NO) (except for 144 and 288 h) levels were reduced, as well.ConclusionsIn conclusion, curcumin reduced tissue injury, trypsin activation and inhibited NF-κB and AP-1. However TNF-α, IL-6 and iNOS and NO were not inhibited at all time points. Therefore no direct correlation was detected in the subgroups between tissue injury, proinflammatory cytokines and oxidative enzymes.  相似文献   
103.
Increases in the generation of reactive oxygen species and decreases in antioxidant enzyme activities with aging have been reported in the prostate, and are also observed in age-related disorders such as atherosclerosis, Alzheimer's disease, and cataracts. Several studies have demonstrated that proteins are targets for reactive oxidants in cells, and that oxidized proteins accumulate during aging, oxidative stress and in some pathological conditions. However, only a limited number of studies have actually evaluated oxidative damage in relation to HDL-cholesterol-associated antioxidant enzyme activities or have assessed its relationship with prostate cancer. In this study, we examined the effect of HDL-cholesterol-associated antioxidant enzyme activities, paraoxonase1, arylesterase and new oxidative stress parameters (total oxidant status, total antioxidant status [and oxidative stress index]) in newly-diagnosed prostate cancer patients and healthy controls. There were no significant differences in oxidative stress parameters and lipid parameters between prostate cancer patients and controls, however, paraoxonase1 enzyme activity, and non-HDL-cholesterol levels were higher in prostate cancer patients than controls. The results of this study were derived from a small number of subjects, but might represent an important working hypothesis for further research in a larger number of cases to clarify the role of paraoxonase1 overproduction on the prostate and its clinical relevance.  相似文献   
104.
Therapeutic plasma exchange (TPE), is a procedure, changing pathologic substances in the plasma of patients with replacement fluid. TPE has an increasing list of indications in recent years such as neurological, connective tissue, hematological, nephrological, endocrinological and metabolic disorders. We report our multicenter data about therapeutic plasma exchange in patients with neurological diseases. Six University Hospitals’ aphaeresis units medical records about neurologic diseases were reviewed retrospectively. Hundred and fifteen patients and 771 TPE sessions from six aphaeresis units’ were included to this study. Of the 115 patients, 53 (46%) were men and 62 (54%) were women. The median age was 50 (range: 5–85) years. Of these patients 58.3% were Guillain–Barre syndrome (GBS), 17.4% were acute disseminated encephalomyelitis (ADEM), 10.4% were chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), 7% were multiple sclerosis, 6.1% were myasthenia gravis (MG) and 0.9% were Wilson disease (WD). The median number of TPE sessions per patient was 5 (range 1–72). Human albumin was used as a replacement fluid in 66% and fresh frozen plasma was used in 34% of cases. TPE was done through central venous catheters in 66%, and peripheral venous access in 34% of patients. Some complications were seen in patients (18.3%) during TPE sessions. These complications were, complications related to catheter placement procedure (8.7%), hypotension (3.5%), hypocalcaemia (3.5%) and allergic reactions (1.7%). The complication ratios were 2.7% in total 771 TPE procedures. TPE procedure was terminated in 6% of sessions depending on these complications. Overall responses to TPE were noted in 89.5% of patients.In conclusion; Therapeutic plasma exchange is an effective treatment option in several neurologic diseases.  相似文献   
105.
Angina bullosa haemorrhgica is a relatively uncommon condition characterized by blood-filled subepithelial lesions in the oral mucosa that is idiopathic and not caused by a systemic disease or a hemostatic abnormality. Middle-aged and elderly patients are usually affected and lesions heal spontaneously without scarring. A rapidly expanding hemorrhagic blister in the oropharynx can induce upper airway obstruction, so recognizing the lesion as soon as possible is essential. Because of its rarity, we wanted to highlight a 42-year-old male patient who presented with hemorrhagic bullae associated with insignificant local trauma in the oral mucosa and to emphasize that Angina bullosa haemorrhagica is a rare but recognizable lesion that clinicians should be aware of.  相似文献   
106.
107.
The plasma concentration of asymmetrical dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, has been linked to endothelial dysfunction. We investigated the relation between plasma ADMA concentration and severity of erectile dysfunction (ED) and coronary artery disease (CAD). We measured plasma levels of ADMA in 92 male patients. Patients were divided into three groups: group 1 (n = 41), patients with ED and without CAD; group 2 (n = 29), patients with stable CAD; group 3 (n = 22), control group (patients without CAD or ED). Erectile function was evaluated by the erectile function domain of the international index of erectile function (IIEF-EFD) a validated 15-item self-administered questionnaire. Erectile function is specifically addressed by six questions that form the so-called erectile function domain of the questionnaire. Each question is scored 0–5. ED is defined as any value <26. Patients with CAD who have stable angina pectoris were selected after coronary angiography. ADMA was analyzed by ELISA method. Group 1 had significantly higher concentrations of plasma ADMA than groups 2 and 3 (respectively, 0.75 ± 0.40 vs. 0.50 ± 0.30, P = 0.013; 0.75 ± 0.40 vs. 0.50 ± 0.25, P = 0.021). There was negative correlation between ADMA and IIEF-EFD score in all groups (n = 92) (r = −0.322, P = 0.002). In a multiple logistic regression analysis adjusting for age, hyperlipidemia, ADMA remained independent predictor for severe ED. Odds ratio for plasma ADMA was 14.151 (1.101–181.940; P = 0.042). First of all, this study provides that ADMA concentrations are significantly higher in patients who have ED when compared to patients with CAD and controls. Second, there was a negative correlation between ADMA and severity of ED. Elevating levels of circulating ADMA is an independent risk factor for severe of ED, and ADMA may be a link between CAD and ED.  相似文献   
108.
Recently, it has been reported that ankylosing spondylitis (AS) was characterised by endothelial dysfunction and the development of atherosclerotic complications. In this study, we evaluated platelet and endothelial activation parameters in AS patients. Fiftynine AS patients and 22 healthy controls were included. The clinical features and acute phase parameters were evaluated. In all patients and healthy controls, platelet-monocyte complexes (PMC), platelet-neutrophil complexes, basal and ADP-stimulated P-selectin (CD62P) expression were determined by flow cytometry; soluble E-selectin (sE-selectin) and soluble CD40L (sCD40L) were determined by ELISA. AS patients were divided into two groups as active and inactive by using BASDAI. In 15 AS patients, the evaluated parameters were assessed before and after 12 weeks of anti-TNF therapy. PMC and sCD40L levels in AS patients were significantly higher than in the control group (P values 0.013 and 0.016). The evaluated variables were similar in active and inactive AS groups (P > 0.05). There were no significant changes in platelet and endothelial activation parameters in AS patients after anti-TNF therapy (P > 0.05). Platelet activation which is reflected by high levels of PMC and sCD40L might be responsible for the increased frequency of atherosclerosis in AS. The platelet activation in our AS patients was not associated with disease activity and did not improve after anti-TNF therapy.  相似文献   
109.
The micro-percutaneous nephrolithotomy (microperc) is a recently introduced percutaneous nephrolithotomy (PNL) technique that is performed through a 4.8Fr all-seeing needle. We aimed to measure the intrarenal pelvic pressure (IPP) during microperc and compare it with the levels of conventional PNL. A total of 20 patients with 1- to 3-cm renal calculi resistant to shock wave lithotripsy were treated either with microperc (Group-1, n: 10) or conventional PNL (Group-2, n: 10) by the same surgical team. The IPP was measured during different stages (entrance into the collecting system, stone fragmentation, and before termination) of the procedures by an urodynamic machine using the 6Fr ureteral catheter. All the variables were statistically compared between the two groups. The demographic values of the patients were similar. The operation time and duration of hospitalization were significantly prolonged in conventional PNL group (p = 0.034, p = 0.01, respectively). The mean drop in hematocrit levels was significantly lower in microperc group (3.5 ± 1.5 vs. 1.8 ± 0.8; p = 0.004). The IPP was significantly higher in microperc group during all steps of the procedure. The highest level of the IPP was measured as 30.3 ± 3.9 and 20.1 ± 3.1 mmHg in Group 1 and Group 2, respectively (p < 0.0001). However, the complication and success rates were found comparable. In conclusion, we demonstrate that the level of IPP is significantly increased during microperc compared to conventional PNL. Microperc should be used cautiously in cases with impaired drainage of the collecting system.  相似文献   
110.
The effect of renal transplantation on pulmonary function.   总被引:1,自引:0,他引:1  
In patients with chronic renal failure, mechanical and hemodynamic changes could occur in the lungs without obvious pulmonary symptoms and findings and their effects could pave the way to pulmonary functional disorders. In this study, pulmonary functional disorders and especially alveolocapillary defects, which are frequently seen in uremia, were determined in renal transplanted patients. Pulmonary functions and diffusion capacity were assessed in uremic patients (n = 20) and in successfully transplanted patients (n = 20) without any lung disease or pulmonary edema symptoms and findings. Patients were selected randomly among outpatients who were followed up in a Nephrology and Transplantation Unit. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow (PEF25-75) were measured. Single breath carbon monoxide diffusion test and diffusion lung capacity adjusted for hemoglobin concentration (DLAdj) were done. The means of the spirometric values such as FVC, FEV1 and FEV1/FVC were normal in the nondialyzed uremic group, but the PEF25-75 value (68.7%) and diffusion capacity (DLAdj 72.7%) were found to be slightly low. There were 2 patients with normal values and 18 patients with some functional abnormalities in this nondialyzed uremic group. The means of all spirometric parameters and diffusion capacities were found to be normal in the transplanted group. There were 7 patients with normal function and 13 patients with some functional abnormalities in this transplanted group. When the nondialyzed uremic group and the transplanted group were compared statistically, significant differences were found between their spirometric values (except for FVC) and their diffusion capacities. Even though the uremic patients did not show any symptoms, their pulmonary function tests, especially diffusion capacity, were found to be disturbed. Although the transplanted patients as a group had normal mean spirometric values and diffusion capacity there were nevertheless many individual transplanted patients with defective diffusion capacity and abnormal spirometric values.  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