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   349篇
  免费   21篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   23篇
妇产科学   19篇
基础医学   40篇
口腔科学   3篇
临床医学   41篇
内科学   76篇
皮肤病学   5篇
神经病学   14篇
特种医学   12篇
外科学   80篇
综合类   5篇
预防医学   9篇
眼科学   4篇
药学   21篇
肿瘤学   12篇
  2023年   2篇
  2022年   6篇
  2021年   4篇
  2020年   4篇
  2019年   9篇
  2018年   10篇
  2017年   1篇
  2016年   13篇
  2015年   12篇
  2014年   23篇
  2013年   19篇
  2012年   31篇
  2011年   36篇
  2010年   17篇
  2009年   12篇
  2008年   23篇
  2007年   28篇
  2006年   36篇
  2005年   29篇
  2004年   21篇
  2003年   15篇
  2002年   10篇
  2001年   4篇
  2000年   3篇
  1992年   1篇
  1987年   1篇
  1977年   1篇
排序方式: 共有371条查询结果,搜索用时 31 毫秒
31.
Copper has an important role in cancer growth, angiogenesis, and metastasis. Previous studies have shown that cell-permeable metal ligands, including clioquinol (CQ) and pyrrolidine dithiocarbamate, inhibit cancer cell growth in cell culture and in vivo. The mechanism of action has not been fully determined but may involve metal-mediated inhibition of cancer cell proteasome activity. However, these studies do not fully account for the ability of cell-permeable metal ligands to inhibit cancer cell growth without affecting normal cells. In this study, we examined the effect of CQ on macrophage-mediated inhibition of HeLa cancer cell growth in vitro. When CQ was added to RAW 264.7 macrophage-HeLa cell cocultures, a substantial increase in HeLa cell toxicity was observed compared with CQ treatment of HeLa cells cultured alone. Transfer of conditioned medium from CQ-treated macrophages to HeLa cells also induced HeLa cell toxicity, demonstrating the role of secreted factors in the macrophage-mediated effect. Further investigation revealed that CQ induced copper-dependent activation of macrophages and release of tumor necrosis factor (TNF) alpha. In studies with recombinant TNFalpha, we showed that the level of TNFalpha released by CQ-treated macrophages was sufficient to induce HeLa cell toxicity. Moreover, the toxic effect of conditioned medium from CQ-treated macrophages could be prevented by addition of neutralizing antibodies to TNFalpha. These studies demonstrate that CQ can induce cancer cell toxicity through metal-dependent release of TNFalpha from macrophages. Our results may help to explain the targeted inhibition of tumor growth in vivo by CQ.  相似文献   
32.
BACKGROUND: CD200:CD200R interactions deliver immunoregulatory signals. A family of CD200Rs (CD200R1-5) has been described, and engagement of CD200R1 by its ligand CD200 suppresses LPS-induced macrophage cytokine production, decreases alloimmune responses in vivo and in vitro, and suppresses collagen-induced arthritis. METHODS: We generated C57BL/6 mice lacking the genomic exons encoding the extracellular domains of the CD200R1 molecule using transformation of ES cells and explored cell subtypes and immune responses in these mice. RESULTS: Myeloid cells/splenocytes from CD200R1(-/-) mice were not stained in FACS by anti-CD200R1 mAb. Stimulation of splenic tumor necrosis factor-alpha production by lipopolysaccharide was enhanced relative to control (+/+) mice and was not suppressed by addition of exogenous CD200Fc. Modulation of alloreactivity in mixed leukocyte cultures by CD200Fc depended upon CD200R1+ stimulatory cells, although maximal immunoregulation by CD200Fc occurred only when CD200R1+ T responder cells also were used. CD200Fc failed to suppress graft rejection in CD200R1(-/-) mice. CONCLUSION: CD200:CD200R1 plays an immunoregulatory role in vivo.  相似文献   
33.
Evoked potentials in children with Wilson's disease   总被引:1,自引:0,他引:1  
We assessed multimodal evoked potentials (EPs) in 13 children with newly diagnosed neurologically symptomatic Wilson's disease (WD) and in their first degree symptom-free relatives, consisting of seven presymptomatic and 15 asymptomatic siblings and 22 asymptomatic parents. EP abnormalities of at least one modality and one side stimulation were observed in 38.5% of patients, 42.9% of presymptomatic siblings, 21.4% of asymptomatic siblings and 18.2% of parents. Patients tended to have more prolonged central latencies of EPs. However, the left I-V interpeak brainstem auditory EP latency difference was the only one to reach at the statistical significance (P = 0.001). Abnormal VEP P100 latency was detected more frequently in presymptomatic siblings than those in asymptomatic ones (42.9% vs 7.1%, P = 0.049). In all relatives, other diagnostic tests including electroencephalography, electromyography and head magnetic resonance imaging (MRI) for subclinical nervous system involvement and Kayser-Fleischer rings examination yielded normal results. In pre/asymptomatic siblings, genetic and biochemical studies may aid to initiate treatment prior to the development of permanent tissue damage. Our results indicate that abnormal EPs may signal unique pathological finding in some subjects. Importantly, these abnormalities occur earlier than Kayser-Fleischer rings and MRI lesions. In early stages of WD, EP recordings may, therefore, be used to help decide on treatment initiation and treatment efficacy evaluation. Moreover, EP recordings can readily be added to family screening studies.  相似文献   
34.
International Ophthalmology - To evaluate the changes in retinal microvasculature in eyes with anterior uveitis (AU) using optical coherence tomography angiography. Foveal avascular zone (FAZ) of...  相似文献   
35.
Patients with systemic amyloidosis often have symptoms related to impared gastrointestinal motility due to delayed gastric emptying, which results from autonomic nerve or smooth muscle infiltration with amyloid. There is no current report about gastric delaying secondary to amyloidosis due to familial Mediterranean fever. In this report, we have described a renal transplant recipient with delayed gastric emptying secondary to amyloidosis due to familial Mediterranean fever, which improved with erithromycin treatment.  相似文献   
36.
Recent studies have clearly reported that there is a relationship between endotoxemia and acute renal injury. The aim of this study was to investigate whether treatment with the new potent PARP inhibitor PJ34 could prevent the acute renal injury induced by lipopolysaccharide (LPS). Endotoxemia was induced by LPS injection (10 mg/kg, i.v.). LPS increased blood urea nitrogen (BUN) levels from 22 +/- 0.54 mg/dL to 45.7 +/- 5.79 mg/dL (p < 0.05). The plasma creatinine levels were 0.38 +/- 0.02 mg/dL and 0.47 +/- 0.03 mg/dL for the control and LPS groups, respectively. In addition, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG, a marker of renal tubular damage) was increased after LPS injection. By light microscopy, structural renal damage was observed in the LPS-treated group. However, PJ34 treatment (10 mg/kg, i.p.) attenuated LPS-induced renal injury, as indicated by plasma BUN and creatinine levels, urinary NAG excretion, and renal histology. These results indicated that the overactivation of the PARP pathway may have a role in LPS-induced renal impairment. Hence, pharmacological inhibition of this pathway might be an effective intervention to prevent endotoxin-induced acute renal injury.  相似文献   
37.
AIMS: The association of mild renal dysfunction (estimated glomerular filtration rate [eGFR] 60-89.9 ml/min/1.73 m(2)) with insulin resistance (IR) or metabolic syndrome (MS) needs be investigated in a population in which MS prevails. METHODS: After excluding subjects with diabetes mellitus, 1,678 subjects from a representative cohort (median age 52 years) were studied cross-sectionally. eGFR was based on serum creatinine concentrations using the quadratic GFR equation and categorized by 90 and 60 ml/min/1.73 m(2) as limits. MS was identified using the modified criteria of the Adult Treatment Panel-III. RESULTS: In men, whereas MS was not significantly associated with a reduced eGFR category when controlled for homeostatic model assessment (HOMA), HOMA adjusted for MS or for its components was significantly associated with the likelihood of a reduced eGFR. This likelihood was increased by 14% with a doubling of HOMA in men. Age was the dominant correlate of reduced eGFR in women, whereby an association with HOMA was not significant. CONCLUSION: Mildly impaired kidney function is common in nondiabetic adults among whom MS prevails, and in men it is mainly associated with IR but not with central obesity and MS-related dyslipidemia. The quadratic GFR equation enables an acceptable estimation of GFR in a general population.  相似文献   
38.
Urinary tract infections are among the most common infections with an increasing resistance to antimicrobials. The aim of this study was to determine the change in antimicrobial susceptibility of Escherichia coli isolates from patients with community-acquired urinary tract infection (UTI) for the years 1998 through 2003 and to suggest that the current empirical antibiotic therapy used for these patients is inappropriate. During the study period, 7,335 community urine samples of which 1,203 (16.4%) grew bacterial isolates were analyzed. Among the total of 1,203 isolates, 880 (73.2%) were E. coli. The range of resistance of E. coli to ampicillin was 47.8 to 64.6% and that to trimethoprim-sulfamethoxazole was 37.1 to 44.6% during the study period. The susceptibility pattern of E. coli to nitrofurantoin and cefuroxime did not vary significantly over the 6-year period. There was a significant increase in the susceptibility of E. coli to ciprofloxacin (11.3 - 26.7%), amoxicillin-clavulanate (18.4 - 29.2%) and gentamicin (7.0 - 25.6%) (P < 0.05). Empirical initial treatment with ampicillin and trimethoprim-sulfamethoxazole was thus inadequate in approximately half of UTI cases in our region.  相似文献   
39.

Objective

The aim of this study was to determine the cardiometabolic risk factors in different polycystic ovary syndrome (PCOS) phenotypes.

Subjects and Methods

This cross-sectional study was performed between 2010 and 2011. Eighty-nine patients with PCOS and 25 age- and weight-matched healthy controls were included in the study. Patients were grouped using the Rotterdam 2003 criteria as: group 1, oligomenorrhea and/or anovulation (ANOV) and hyperandrogenemia (HA) and/or hyperandrogenism (n = 23); group 2, ANOV and polycystic ovaries (PCO; n = 22); group 3, HA and PCO (n = 22); group 4, ANOV, HA and PCO (n = 22); group 5, controls (n = 25). Laboratory blood tests for diagnosis and cardiometabolic risk assessments were performed. Insulin resistance (IR) was calculated in all patients with the homeostasis model assessment of IR (HOMA-IR) formula. An euglycemic hyperinsulinemic clamp test was performed on 5 randomly selected cases in each subgroup, making 25 cases in total, and indicated as the ‘M'' value (mg/kg/min), which is the total body glucose disposal rate.

Results

The mean BMl values of the groups were: group 1, 26.1 ± 5.3; group 2, 27.9 ± 5.2; group 3, 24.3 ± 4.2; group 4, 27.9 ± 7.5; group 5, 24.7 ± 5.2 (p > 0.05). There were no differences in the lipid profile, plasma glucose, HOMA-IR, insulin and M values between the groups (p > 0.05). Phenotypes with oligomenorrhea/anovulation (groups 1, 2 and 4) were more obese than group 3 (p = 0.039).

Conclusions

The cardiometabolic risk profile was similar among the PCOS subgroups. This finding could be attributed to the mean BMl values, which, being below 30, were not within the obesity range. Obesity appeared to be an important determinant of high cardiovascular risk in PCOS.Key Words: Polycystic ovary syndrome, Cardiovascular system, Obesity  相似文献   
40.
OBJECTIVE: The aim of this study is to analyse the factors affecting emergency department (ED) cardiopulmonary resuscitation (CPR) outcome. METHODS: A standard CPR protocol was performed in all patients and certain pre and postresuscitation parameters including age, sex, initial arrest rhythm, primary underlying disease, initiation time of advanced cardiac life support, duration of return of spontaneous circulation were recorded. Patients were followed up to determine rates of successful CPR, survival and one-year survival. RESULTS: From December 1999 to May 2001, 80 consecutive adult patients in whom a standard CPR was performed in the ED were prospectively included in the study. The overall rate for successful CPR, survival and one-year survival were found to be 58.8% (47/80), 15% (12/80) and 10% (8/80), respectively. Survival and one-year survival rates were better in patients with an initial arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) than both pulseless electrical activity (pEA) and asystole; survival and one-year survival rates were better in patients with a primary underlying disease of cardiac origin than non-cardiac origin. Acute myocardial infarction had the best prognosis among conditions causing arrest. Presence of sudden death was found to have a better survival and one-year survival rate. CONCLUSION: Initial cardiac rhythm of VF/pVT, cardiac origin as the primary disease causing cardiopulmonary arrest and presence of sudden death were found to be good prognostic factors in CPR.  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