151 research outputs found

    Effect of Zinc Galvanization on the Microstructure and Fracture Behavior of Low and Medium Carbon Structural Steels

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    Microstructure and fracture behavior of ASTM 572 Grade 65 steels used for wind tower applications have been studied. Steels of two carbon level chemistries designed for this grade were used in the study. Fracture toughness of the steels was studied using 3-point bend test on samples coated with zinc and not coated with zinc. Lower carbon steel showed higher resistance to fracture than medium carbon steel after zinc galvanization. SEM study suggests that zinc and zinc bath additives that migrated to crack tips are responsible for the loss in ductility. The phenomenon of Liquid Metal Embrittlement (LME) is suggested to have taken place. Zinc bath additives traced at crack zones are suggested to have migrated at the zinc galvanizing temperatures

    E-Learning And Instructional Management System Based On Local Computer Networks And Internet

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    This article describes the educational efforts invested at Wasit University (WU), in Wasit, Iraq, in order to make WU the first university in that country to implement campus-wide e-learning, which is essential for any country aiming for progress through the essential goal of “Education For All”; e-learning being economic, far-reaching, and relatively simple to implement. These efforts have materialized in an integral e-system that performs and manages a complete educational process that can be used by any educational organization (schools, colleges, or continuing education centers) in a highly flexible, reliable, and secure manner. The e-learning management system architecture consists of three layers: user’s interface layer, middle layer, and server layer. The user interface layer is composed of four modules: user interface module, teacher module, student module, and administrator module. Each module has several sub-modules that are described in detail throughout the paper. Our proposed e-learning system has been successfully tested on some courses in the Electrical Engineering Department at WU. Our primary objective is to implement it department-wide, evaluate it, and refine it. Once satisfactory and efficient, the goal is to expand its use throughout WU, and eventually to all other institutions of learning in Iraq

    HARNESSING THE ANTIOXIDANT PROPERTY OF CERIUM AND YTTRIUM OXIDE NANOPARTICLES TO ENHANCE MESENCHYMAL STEM CELL PROLIFERATION

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    Objective: This work was designed to explore if cerium oxide (CeO2) and yttrium oxide (Y2O3) nanoparticles as antioxidant agents could potentiate the proliferation of mesenchymal stem cells (MSCs) derived from human dental pulp (hDPSCs).Methods: Nanoparticles were characterized by transmission electron microscopy, particle size and zeta potential, X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscope (SEM) along with energy-dispersive X-ray spectrometry. Furthermore, MSCs were isolated from human dental pulp, propagated and characterized by flow cytometry. Thereafter, the proliferative impact of the suggested nanoparticles on hDPSCs was investigated by 3-(4,5)-dimethylthiazol)-2,5-diphenyl tetrazolium bromide assay.Results: Different sizes (14.09–26.50 nm and 18.80–31.31 nm) for CeO2 and Y2O3 respectively, morphology, charges, and proliferative efficacy in hDPSCs were recorded for both nanoparticles.Conclusion: Generally speaking, the tested nanoparticles heightened the proliferative response of hDPSCs with the most prominent effect exerted by 15 μg/ml of CeO2 and 5 μg/ml of Y2O3. It is reasonable to assume that the antioxidant property of CeO2 and Y2O3 be involved in strengthening the proliferation process of hDPSCs

    Clinical, anthropometric, radiological and molecular characteristics of Egyptian achondroplasia patients

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    Background: Achondroplasia is the most common form of non lethal skeletal dysplasia. It is a fully penetrant autosomal dominant disorder and the majority of cases are sporadic resulting from de novo mutations associated with advanced paternal age. The phenotype of achondroplasia is related to disturbance in endochondral bone formation due to mutations in the fi broblast growth factor receptor-3 (FGFR3) gene. Aim of the Work: Evaluation of the cardinal phenotypic features in achondroplasia, the body physique using anthropometric measurements, the characteristic radiological signs in the patients as a main tool for diagnosis and detection of the most common mutations in achondroplasia patients in the studied sample.Subjects and Methods: From 42 cases referred to us as achondroplasia, we selected 20 cases where clinical manifestations were consistent with achondroplasia. Cases were subjected to full clinical examination, detailed anthropometric measurements, whole body skeletal survey and molecular studies of the most common mutations of the FGFR3 gene using PCR amplifi cation technique. Results: Nineteen cases were sporadic (95%) and one case had an affected father (5%). A paternal age above 35 years at the time of child’s birth was present in 7 cases (35%). Paternal exposure to occupational heat was noted in 6 cases (30%) and parental exposure to chemicals in 3 cases (15%). All cases showed typical clinical and radiological manifestations of achondroplasia. Anthropometricmeasurements quantitatively confi rmed the body physique in thestudied cases. G380R common mutations of the FGFR3 gene were detected in 15/18 cases (83%) with the G to A transition at nucleotide 1138 in 14 cases (77%). Agenesis of corpus callosum, not previously reported in association with achondroplasia, was present in the only case with the G-C transversio nmutation at nucleotide 1138 (5%).Conclusions: Awareness of the cardinal features of achondroplasia, properanthropometric measurements and detailed skeletal survey are the key foraccurate diagnosis, genetic counseling and avoidance of over diagnosis. The majority of studied Egyptian achondroplasia patients have the same common mutation that has been most often defi ned in patients with achondroplasia from other countries.Keywords: Achondroplasia, fi broblast growth factor receptor3,skeletal dysplasia, paternal heat exposure

    Fungal Populations in Air and Materials in a Flood Simulation Study

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    Air quality was measured in a building subjected to flooding conditions analogous to that which occurred during Hurricane Katrina. This building was flooded to a depth of 0.61 m above the floor with pond water and maintained at that level for 3 wk. After the floodwater was drained, the building remained closed for an additional 3 wk. Immediately on opening, air samples were obtained and analyzed for fungal spores. Dry and wet material components of the building wall were analyzed for the presence of mold fungi by both culture and molecular techniques. Additional air samples were taken after a 30-da drying period and then after remediation of the building. The air measurements demonstrated the presence of high concentrations of indoor mold spores when the building was initially entered. Aspergillus/Penicillium were the dominate air molds. Fiberglass batt insulation supported the greatest concentration of culturable fungi, compared with other wall materials, followed by the paper facings of gypsum board and plywood sheathing. The solid wood stud, vinyl siding, and house wrap all supported low concentrations of culturable mold. After drying, the spore air contamination diminished more than 10-fold and the species of fungi on the materials drastically changed. After remediation, the spores inside the structure nearly matched those outside with respect to type and concentration

    Predictors of suicidality across the life span: The Isle of Wight study

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    Background Data from a representative community sample were used to explore predictors of lifetime suicidality and to examine associations between distal adolescent and more proximal adult risks. Method Data are from a midlife follow-up of the Isle of Wight study, an epidemiological sample of adolescents assessed in 1968. Ratings of psychiatric symptoms and disorder, relationships and family functioning and adversity were made in adolescence; adult assessments included lifetime psychiatric history and suicidality, neuroticism and retrospective reports of childhood sexual abuse and harsh parenting. Results A wide range of measures of childhood psychopathology, adverse experiences and interpersonal difficulties were associated with adult suicidality; associations were particularly strong for adolescent irritability, worry and depression. In multivariate analyses, substantial proportions of these effects could be explained by their association with adult psychopathology and neuroticism, but additional effects remained for adolescent irritability and worry. Conclusions Factors of importance for long-term suicidality risk are evident in adolescence. These include family and experiential adversities as well as psychopathology. In particular, markers of adolescent worry and irritability appeared both potent risks and ones with additional effects beyond associations with adult disorder and adult neuroticism

    Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study.

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    PurposeOsteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI.MethodsUsing data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves.ResultsIn children, the median z-scores for height in OI types I, III, and IV were -0.66, -6.91, and -2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was -4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P < 0.001), age, bisphosphonate use, and rodding (P < 0.05).ConclusionFrom the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves

    Cellular stress due to impairment of collagen prolyl hydroxylation complex is rescued by the chaperone 4-phenylbutyrate

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    Osteogenesis imperfecta (OI) types VII, VIII and IX, caused by recessive mutations in cartilage associated protein (CRTAP), prolyl-3-hydroxylase 1 (P3H1), and cyclophilin B (CyPB), respectively, are characterized by the synthesis of overmodified collagen. The genes encode for the components of the endoplasmic reticulum (ER) complex responsible for the 3-hydroxylation of specific proline residues in collagen type I. Our study dissects the effects of mutations in the proteins of the complex on cellular homeostasis, using primary fibroblasts from seven recessive OI patients. In all cell lines the intracellular retention of overmodified type I collagen molecules causes ER enlargement associated to the presence of protein aggregates, activation of the PERK branch of the unfolded protein response and apoptotic death. The administration of 4-phenylbutyrate (4-PBA) alleviates cellular stress by restoring ER cisternae size, normalizing the p-PERK/PERK ratio and the expression of apoptotic marker. The drug has also a stimulatory effect on autophagy. We proved that the rescue of cellular homeostasis following 4-PBA treatment is associated to its chaperone activity, since it increases protein secretion, restoring ER proteostasis and reducing PERK activation and cell survival also in presence of autophagy pharmacological inhibition.Our results provide a novel insight into the mechanism of 4-PBA action and demonstrated that the intracellular stress in recessive OI can be tuned by 4-PBA therapy, similarly to what we recently reported for dominant OI, thus allowing a common target for OI forms characterized by overmodified collagen

    Mutations in SCNM1 cause orofaciodigital syndrome due to minor intron splicing defects affecting primary cilia

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    Orofaciodigital syndrome (OFD) is a genetically heterogeneous ciliopathy characterized by anomalies of the oral cavity, face, and digits. We describe individuals with OFD from three unrelated families having bi-allelic loss-of-function variants in SCNM1 as the cause of their condition. SCNM1 encodes a protein recently shown to be a component of the human minor spliceosome. However, so far the effect of loss of SCNM1 function on human cells had not been assessed. Using a comparative transcriptome analysis between fibroblasts derived from an OFD-affected individual harboring SCNM1 mutations and control fibroblasts, we identified a set of genes with defective minor intron (U12) processing in the fibroblasts of the affected subject. These results were reproduced in SCNM1 knockout hTERT RPE-1 (RPE-1) cells engineered by CRISPR-Cas9-mediated editing and in SCNM1 siRNA-treated RPE-1 cultures. Notably, expression of TMEM107 and FAM92A encoding primary cilia and basal body proteins, respectively, and that of DERL2, ZC3H8, and C17orf75, were severely reduced in SCNM1-deficient cells. Primary fibroblasts containing SCNM1 mutations, as well as SCNM1 knockout and SCNM1 knockdown RPE-1 cells, were also found with abnormally elongated cilia. Conversely, cilia length and expression of SCNM1-regulated genes were restored in SCNM1-deficient fibroblasts following reintroduction of SCNM1 via retroviral delivery. Additionally, functional analysis in SCNM1-retrotransduced fibroblasts showed that SCNM1 is a positive mediator of Hedgehog (Hh) signaling. Our findings demonstrate that defective U12 intron splicing can lead to a typical ciliopathy such as OFD and reveal that primary cilia length and Hh signaling are regulated by the minor spliceosome through SCNM1 activity.This work was supported by a grant from the Spanish Ministry of Science and Innovation (PID2019-105620RB-I00/AEI/10.13039/501100011033)
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