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Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada in the area of concrete materials research has shown the potential of improving concrete properties by modifying the structure of cement hydrates, addition of nanoparticles and nanotubes and controlling the delivery of admixtures. This article will focus on a review of these innovative achievements. 相似文献
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目的 探讨长期大量慢性饮酒、吸烟等不良生活方式与骨质疏松的关系.方法 以乏力、腰背痛、双下肢酸困为主诉,且有长期大量慢性饮酒史、吸烟史,无其他慢性疾病史的年轻男性患者45例为观察对象,测定其血钙(Ca)、血磷(P)和血肌酐(Cr)、尿素氮(BUN)、血糖(Glu)、天门冬酸氨基转移酶(AST)、丙氨酸基转移酶(ALT)、血清碱性磷酸酶(ALP)、甲状腺功能、全段甲状旁腺激素(iPTH)、1,25-二羟维生素D3[1,25-(OH) 2D3]、双能X线骨密度仪测定腰椎L1-4及左侧股骨近段(包括颈、股骨颈上部、大粗隆)骨密度(BMD),分析饮酒、吸烟对骨量的影响.以感冒发热就诊、年龄相当、无饮酒、吸烟史及慢性疾病史的45例男性为对照组.结果 观察组1,25(OH)2D3水平均降低,血钙水平偏低,血磷正常,碱性磷酸酶呈不同程度地升高,骨密度T值提示观察组27例骨质疏松,12例骨量减少,6例正常骨量;而对照组仅有6例为骨量减少,1例骨质疏松,38例为正常骨量,两组比较差异有统计学意义(P<0.05).结论 长期慢性大量饮酒吸烟影响骨量,甚至易导致骨质疏松. 相似文献
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Rachel J. Snyder 《Gerontology & geriatrics education》2013,34(3):235-255
The current study surveys medical and doctoral psychology students (N = 100) from an urban northeastern university regarding knowledge and attitudes toward elderly sexuality and aging using the Facts on Aging Quiz, the Aging Sexuality Knowledge and Attitudes Scale, and measures of interest in gerontology, academic/clinical exposure to aging and sexuality, and contact with elders. The current study found that psychology students demonstrated greater aging knowledge than medical students; however, both groups showed gaps in knowledge about sexuality. Married students had greater academic/clinical exposure and greater knowledge about aging but less permissive attitudes toward elderly sexuality. Generally, knowledge about aging was the strongest correlate of knowledge about sexuality. Level of knowledge about sexuality was not associated with attitudes. Attitudes toward sexuality and aging may be more strongly tied to demographic variables reflective of religious beliefs or adherence to sociocultural norms. 相似文献
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在动脉粥样硬化的发生发展过程中,自身免疫具有重要作用,本文就近年有关动脉粥样硬化的免疫机制的研究进展作一简要综述. 相似文献
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Motivala SJ Dang J Obradovic T Meadows GG Butch AW Irwin MR 《Alcoholism, clinical and experimental research》2003,27(11):1819-1824
BACKGROUND: Basic studies indicate that in vitro and in vivo doses of leptin modulate cellular immune responses. Given evidence that concentrations of leptin are altered in alcoholics who also show immune abnormalities, this study examined the relationships between circulating levels of leptin and markers of cellular and innate immunity. METHODS: Circulating levels of leptin, natural killer cell (NK) activity, interleukin-2 (IL-2)-stimulated NK activity, and concanavalin A-stimulated production of IL-2, IL-6, IL-10, and IL-12 were compared between abstinent DSM-IV alcohol-dependent men (n = 27) and age- and gender-matched controls (n = 34). RESULTS: As compared with controls, alcoholics showed lower NK activity (p < 0.01) and a trend for lower levels of leptin (p = 0.055). In the total sample, leptin predicted NK activity (beta = 0.33; p < 0.05) after controlling for the confounding influence of body mass index, alcohol intake, and smoking. Leptin was not correlated with any of the cytokine measures. To examine whether the effects of leptin were mediated by its direct action on NK, additional studies examined in vitro effects of leptin on NK activity in healthy volunteers (n = 10); leptin doses (0.1, 1, and 10 nM) yielded levels of NK activity comparable to those with media alone. CONCLUSIONS: These data show that circulating levels of leptin are associated with NK activity in humans and suggest that abnormal in vivo concentrations of leptin may contribute to the declines of NK activity in alcoholics who are at risk for infectious diseases. 相似文献
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目的探讨中青年超重和肥胖与高血压及高同型半胱氨酸血症的相关性。方法选取2012年1月—2013年10月在我院进行常规健康体检者750例,测量受试者血压、身高、体质量及血清同型半胱氨酸(Hcy)水平。结果男性超重、肥胖检出率分别为36.87%(198/537)和13.97%(75/537),均高于女性的16.43%(35/213)和7.50%(16/213)(P0.05)。超重者和肥胖者高血压和高同型半胱氨酸血症检出率分别为21.03%(49/233)和11.16%(26/233)、46.12%(42/91)和41.76%(38/91),均高于正常者的9.16%(37/404)和2.23%(9/404),肥胖者高于超重者(P0.01)。收缩压(SBP)、舒张压(DBP)及血清Hcy与BMI呈正相关(r值分别为0.639、0.515、0.497,P0.01)。结论中青年尤其是男性超半数存在超重或肥胖,高血压及高同型半胱氨酸血症与BMI呈正相关,超重和肥胖者高血压及高同型半胱氨酸血症的发生率高,应积极防治。 相似文献
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van Staa TP Boulton F Cooper C Hagenbeek A Inskip H Leufkens HG 《American journal of hematology》2003,72(4):248-254
The objectives of this study were to estimate the incidence of idiosyncratic neutropenia and agranulocytosis in England and Wales and to evaluate their risk factors and outcomes. The study was conducted using data from the General Practice Research Database. All cases of idiosyncratic neutropenia or agranulocytosis were identified and the incidence was estimated. This was followed by a nested case-control study, estimating odds ratios with drug exposure from conditional logistic regression. From 1987 to 1999, 3,224 patients with idiosyncratic neutropenia (50 with agranulocytosis) were identified. The incidences of neutropenia and agranulocytosis were estimated to be 120 and 7 cases per million people per year, respectively. The adjusted odds ratios for neutropenia were 34.7 (95% confidence interval 12.0-99.7) for current users of thyroid inhibitors, 9.5 (4.4-20.8) for users of disease-modifying antirheumatic drugs, and 7.6 (4.9-11.9) for users of aminosalicylates. Other drugs with statistically significantly increased risks of neutropenia included antibacterial drugs, non-opioid analgesics, NSAIDs, antidepressants, ulcer-healing drugs, and anti-epileptics. The increase in risk of neutropenia predominantly occurred during the first months of treatment. For most drugs investigated in this study, there was no relationship to daily dose. The excess 1-year mortality was low among neutropenia and agranulocytosis cases and mostly explained by the underlying disease state. In conclusion, the highest risks of neutropenia were generally found in patients starting treatment. The excess 1-year mortality was low among neutropenia and agranulocytosis cases and can be mostly explained by the underlying disease state. 相似文献
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From a survey of 416 gay and bisexual male AIDS caregivers, we examined differences in the stress process and predictors of depressive symptomatology by caregivers' HIV serostatus (n = 164 HIV-positive and n = 252 HIV-negative). Results indicate that HIV-positive caregivers reported higher levels of depressive symptomatology than those who were HIV-negative. Parallel regression analyses revealed that a younger age, role-related stress, and low self-esteem were common predictors of depressive symptomatology for both groups. Group-specific predictors of depression for the HIV-positive caregivers were poorer health and financial concerns. In contrast, the group-specific predictor for the HIV-negative caregivers was higher stress associated with direct acts of caregiving. These results suggest that in order to stem depressive symptomatology, gay and bisexual male caregivers need support directed at reducing stress stemming from their role as caregivers as well as services designed to address low self-esteem. In addition, serostatus should be taken into account when designing service plans because seropositive and seronegative caregivers may require different supportive services. 相似文献
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Janine Jason Bruce Evatt John Murphy Lynn A. Sleeper Sharyne M. Donfield Indira Warrier Steven Arkin Edward D. Gomperts 《American journal of hematology》1994,46(1):29-35
Objectives: To assess relationships among the effects of HIV on hemophilic children and adolescents' immunologic parameters and vaccine-related serology. Methods: We analyzed data from extensive baseline immunologic evaluations of 207 HIV antibody-positive (HIV+) and 126 HIV antibody-negative (HIV?) hemophilic children and adolescents. Results: HIV+ and HIV- participants differed significantly in T-lymphocyte subpopulation numbers, immunoglobulin levels, and seroprevalence rates for diphtheria toxoid, measles, and mumps antigens. IgG levels, IgM levels, and serologic titers to vaccine antigens showed little correlation with T-cell parameters. Proportionately more HIV+ participants were nonreactive to each and all of a panel of 7 skin test antigens (71 % vs 28% anerglc, RR 2.6). The odds of anergy increased 1.6 times for every decline of 200 CD4 ± cells/μTl. Conclusions: HIV had significant, largely independent T- and B-lymphocyte effects on this pediatric cohort. © 1994 Wiley-Liss, Inc. 相似文献
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《The American journal of drug and alcohol abuse》2013,39(5):389-394
Background: Ethanol is primarily metabolized in the liver by two rate-limiting reactions: conversion of ethanol to acetaldehyde by alcohol dehydrogenase (ADH) and subsequent conversion of acetaldehyde to acetate by aldehyde dehydrogenase (ALDH). ADH and ALDH exist in multiple isozymes that differ in their kinetic properties. Notably, polymorphisms within the genes that encode for these isozymes vary in their allele frequencies between ethnic groups, and thus, they have been considered as candidate genes that may differentially influence risk for the development of alcohol dependence across ethnic groups. Objectives and methods: Associations between alcohol dependence and polymorphisms in ADH1B, ADH1C, and ALDH2 were compared in a community sample of Native Americans (n 791) living on reservations and Mexican Americans (n 391) living within the same county. Results: Two Mexican Americans and no Native Americans possessed one ALDH2*2 allele. Presence of at least one ADH1B*2 allele was found in 7% of the Native Americans and 13% of the Mexican Americans, but was only associated with protection against alcohol dependence in the Mexican Americans. Presence of at least one ADH1B*3 allele was found in 4% of the Native Americans and 2% of the Mexican Americans, but was associated with protection against alcohol dependence only in the Native Americans. No associations between alcohol dependence and polymorphisms in ADH1C were found. Conclusions and Scientific Significance: Polymorphisms in ADH1B are protective against alcoholism in these two populations; however, these findings do not explain the high prevalence of alcoholism in these populations. 相似文献
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目的探讨survivin与血管内皮生长因子(VEGF)在肝细胞肝癌(HCC)组织中的表达及其临床意义。方法采用免疫组化法检测50例HCC组织和20例正常肝组织中survivin、VEGF蛋白的表达,并分析其与HCC临床病理参数的关系。结果50例HCC组织中survivin、VEGF蛋白的阳性表达率分别为64.0%、68.0%,在正常肝组织中的表达率分别为0、10%,两者相比,P均〈0.05;survivin、VEGF蛋白表达与HCC临床分期及淋巴结转移相关(P〈0.05);HCC中survivin、VEGF蛋白表达呈正相关(r=0.886,P〈0.05)。结论survivin和VEGF蛋白在HCC中表达率较高,为肝癌的分子靶向治疗提供了新的靶点;survivin和VEGF在HCC中的表达关系密切,对肝癌的发展可能有协同作用;测定HCC中survivin、VEGF蛋白的表达,对判断患者预后及指导治疗有较大帮助。 相似文献
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Chambellan A Coulon S Cavailles A Hermine O Similowski T 《Revue des maladies respiratoires》2012,29(2):213-231
Erythropoiesis is modified in chronic obstructive pulmonary disease (COPD). Tobacco smoke, hypoxaemia, systemic inflammation, and infectious exacerbations are the main factors involved. Polymorphisms in genes involved in the regulation of erythropoiesis probably explain the individual susceptibility and variability in the response. The roles of comorbidities related to COPD and the impact of treatment on erythropoiesis are important confounding factors. While polycythaemia is often related to tobacco smoke and hypoxaemia, it has become less common due to the improvement of COPD follow-up and especially the initiation of long-term oxygen therapy. The control of the main causes is often sufficient, but in cases of severe polycythaemia an erythrapheresis is indicated. Anaemia has recently been reported as a more common and serious complication. It increases dyspnoea and reduces physical activity and quality of life. Its impact on survival and the requirements for healthcare has recently been confirmed. The main approach to the management of anaemia remains exclusion of any curable causes, reducing exacerbations and systemic inflammation, and controlling the comorbidities. Though erythropoietin has some benefits in the so-called "anaemia of chronic disease", this still remains to be confirmed in patients with COPD. 相似文献
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Inhibition of reproductive function by the activation of the stress-response has been observed since times of antiquity, however delineating a molecular mechanism by which this occurs in vertebrates continues to present a major challenge. Because recent genome sequencing programs have identified the presence of numerous paralogous peptides and receptors, our understanding of the complexity of the interaction between the reproductive and stress axes has expanded. At the neuroendocrine level, numerous studies have focused on the interaction between the corticotropin-releasing factor (CRF) and gonadotropin-releasing hormone (GnRH) systems in vertebrates. Moreover, most of these studies have been performed using rodent models and may not be completely relevant for non-mammalian vertebrates. A further problem lies in the variation of the functional expression of paralogous genes in the different taxa. In particular, the urocortin 2 and GnRH-II systems have been lost in some lineages, where its function has been taken over by urocortin 3 and GnRH-I, respectively. Establishing an integrated model that incorporates all paralogous systems for both the stress and reproductive system remains to be achieved. 相似文献
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Salman Razvi Avais Jabbar Alessandro Pingitore Sara Danzi Bernadette Biondi Irwin Klein Robin Peeters Azfar Zaman Giorgio Iervasi 《Journal of the American College of Cardiology》2018,71(16):1781-1796
Thyroid hormone (TH) receptors are present in the myocardium and vascular tissue, and minor alterations in TH concentration can affect cardiovascular (CV) physiology. The potential mechanisms that link CV disease with thyroid dysfunction are endothelial dysfunction, changes in blood pressure, myocardial systolic and diastolic dysfunction, and dyslipidemia. In addition, cardiac disease itself may lead to alterations in TH concentrations (notably, low triiodothyronine syndrome) that are associated with higher morbidity and mortality. Experimental data and small clinical trials have suggested a beneficial role of TH in ameliorating CV disease. The aim of this review is to provide clinicians dealing with CV conditions with an overview of the current knowledge of TH perturbations in CV disease. 相似文献
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McDermott MM Guralnik JM Greenland P Green D Liu K Ridker PM Chan C Criqui MH Ferrucci L Taylor LM Pearce WH Schneider JR Oskin SI 《Journal of the American Geriatrics Society》2004,52(11):1888-1894
OBJECTIVES: To determine whether higher circulating levels of thrombotic and inflammatory markers are associated with greater disability. DESIGN: Cross-sectional. SETTING: Academic medical center. PARTICIPANTS: A total of 346 men and women with peripheral arterial disease (PAD) and 203 without PAD. MEASUREMENTS: Disability measures were the Walking Impairment Questionnaire (WIQ) distance, speed, and stair-climbing scores and the 36-item Short-Form (SF-36) physical functioning score. The SF-36 and WIQ are scored on a 0 to 100 scale (100=best). RESULTS: In persons with PAD, higher D-dimer levels were associated with lower WIQ speed scores (P<.001), lower stair-climbing scores (P<.04), and poorer SF-36 physical functioning scores (P<.01), adjusting for known and potential confounders. In participants without PAD, higher D-dimer levels were associated with lower WIQ distance scores (P<.03), lower speed scores (P<.05), and poorer SF-36 physical functioning scores (P<.02). Higher high-sensitivity C-reactive protein (hsCRP) levels were associated with lower WIQ distance (P<.02) and speed scores (P<.001) in persons without PAD. Most of these associations were attenuated after additional adjustment for objectively measured functional limitations. CONCLUSION: Higher circulating D-dimer and hsCRP levels are associated with greater disability in walking and physical functioning in individuals with and without PAD. Physiological changes that result in walking disability may mediate these associations. 相似文献