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31.
V. Bharath V. Auradi G. B. Veeresh Kumar Madeva Nagaral Murthy Chavali Mahmoud Helal Rokayya Sami NI Aljuraide Jong Wan Hu Ahmed M. Galal 《Materials》2022,15(12)
The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al2O3) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al2O3 MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al2O3 particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al2O3 particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al2O3 composite samples. 相似文献
32.
Mariam Ammar Najla Bahloul Oumayma Amri Ribh Omri Hanene Ghozzi Samy Kammoun Khaled Zeghal Lobna Ben Mahmoud 《Journal of clinical laboratory analysis》2022,36(5)
This study aims to evaluate markers of oxidative stress in Tunisian asthmatic patients and investigate whether their markers are correlated with uncontrolled asthma.This prospective cohort study was conducted on 48 healthy subjects and 60 patients with asthma (34 patients with controlled asthma and 26 patients with uncontrolled asthma). The levels of malondialdehyde (MDA), advanced oxidation protein products (AOPP), and glutathione (GSH), as well as the activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD), were estimated in plasma by spectrophotometry.Asthmatic patients have significantly higher plasmatic levels of MDA and AOPP than healthy controls (p < 0.001). Lower GSH level and GPx activity were found in patients with asthma compared to controls (p < 0.001). In contrast, higher SOD activity was noted in asthmatic patients (p < 0.001).The comparison among the patients with controlled asthma and uncontrolled asthma revealed increased MDA and AOPP levels and SOD activity (p < 0.001) as well as a decreased GSH level and GPx activity (p = 0.004, p = 0.019) in patients with uncontrolled asthma. Spirometry level was significantly correlated with SOD activity (r = 0.447; p = 0.010), whereas no significant correlations were found with the other parameters (MDA, AOPP, GSH, and GPx).Asthmatic patients, especially those with uncontrolled asthma, suffer a high degree of reactive oxygen species (ROS) formation causing considerable oxidative stress. Increased MDA level and SOD activity and reduced GPx activity were predictors of poorly controlled asthma. 相似文献
33.
Tafany A. Alsaawi Dara Aldisi Mahmoud M. A. Abulmeaty Malak N. K. Khattak Abdullah M. Alnaami Shaun Sabico Nasser M. Al-Daghri 《Nutrients》2022,14(9)
Sarcopenia is the loss of skeletal muscle mass, and is most common in older people. The present multi-center cross-sectional study aimed to determine the prevalence of sarcopenia and possible risk factors among Arab elderly females. A total of 131 ambulatory Saudi elderly females aged 60–85 years (mean age 65.9 ± 5.5 years) were recruited to participate. A general questionnaire with questions related to sociodemographic factors, medical history, diet, physical activity, and lifestyle was administered. Anthropometrics and muscle assessments were done. Fasting blood glucose and lipids were measured routinely. Circulating 25(OH)D and irisin levels were measured using commercially available assays. Sarcopenia was assessed using the criteria of the Asian Working Group for Sarcopenia (AWGS). Over-all prevalence of sarcopenia was 19.8% (26 out of 131 participants). Novel measures such as abdominal volume index (AVI), dietary fiber, and irisin were found to be significantly lower in the sarcopenia group than those without sarcopenia, independent of age. No associations were found with physical activity or dietary and lifestyle habits. In conclusion, sarcopenia is relatively common among Arab elderly females. Longitudinal studies are needed to determine whether lifestyle modifications can decrease the incidence of sarcopenia in this population. Irisin maybe a promising biomarker for sarcopenia but needs to be confirmed using larger sample sizes. 相似文献
34.
Nahed Mounir Sherif Mona Mahmoud Arafa Soha Eldessouki Ibrahim Salwa Galal Moussa 《The Egyptian Rheumatologist》2013,35(3):121-126
Aim of the workThe aim of the present study was to measure the level of the chemokine CXC ligand 13 protein (CXCL13) in the plasma and unstimulated saliva of rheumatoid arthritis (RA) patients in order to find out its role in the disease activity and its relation to secondary Sjögren’s syndrome (sSS).Patients and methodsThe study was conducted on thirty rheumatoid arthritis patients attending the Outpatient Clinic of Rheumatology and Rehabilitation department of Ain shams University Hospitals. The patients’ group had been classified into group (1) which included fifteen RA patients associated with sSS diagnosed according to the American–European Consensus Group Classification Criteria and group (2) which included fifteen RA patients not associated with sSS. Ten healthy subjects were included as a control group. Patients were subjected to full history taking, clinical examination, and laboratory detection of CXCL13 level in the plasma and saliva of patients as well as the control groups using ELISA technique. Assessment of disease activity in RA patients was done using the disease activity score (DAS28).ResultsPlasma levels of CXCL13 were significantly higher in RA patients than control group (p < 0.001). Plasma levels of CXCL13 were significantly correlated with the RA disease activity (r = 0.677, p < 0.001) and disease duration (r = 0.406, p < 0.05), while the salivary levels were higher in those with sSS and correlated with sSS disease duration (r = 0.536, p < 0.05). A highly significant correlation was found between salivary CXCL13 and severity of sSS (r = 0.816, p < 0.001). Salivary levels of CXCL13 above 110 pg/ml may diagnose sSS with sensitivity 80% and specificity 84%.ConclusionThe results of this preliminary study point out the importance of CXCL13 as a marker for RA disease activity, its role in diagnosing sSS, and estimation of sSS severity. 相似文献
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Nihal Fathi Samar H. Goma Nadia M. Ismail Abeer M. Ghandour Sally S. Youssef Nisreen A. Mohammed Eman Mosad 《The Egyptian Rheumatologist》2018,40(1):45-49