118 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

    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

    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)

    Incidental cardiac findings on computed tomography imaging of the thorax

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    <p>Abstract</p> <p>Background</p> <p>Investigation of pulmonary pathology with computed tomography also allows visualisation of the heart and major vessels. We sought to explore whether clinically relevant cardiac pathology could be identified on computed tomography pulmonary angiograms (CTPA) requested for the exclusion of pulmonary embolism (PE). 100 consecutive CT contrast-enhanced pulmonary angiograms carried out for exclusion of PE at a single centre were assessed retrospectively by two cardiologists.</p> <p>Findings</p> <p>Evidence of PE was reported in 5% of scans. Incidental cardiac findings included: aortic wall calcification (54%), coronary calcification (46%), cardiomegaly (41%), atrial dilatation (18%), mitral annulus calcification (15%), right ventricular dilatation (11%), aortic dilatation (8%) and right ventricular thrombus (1%). Apart from 3 (3%) reports describing cardiomegaly, no other cardiac findings were described in radiologists' reports. Other reported pulmonary abnormalities included: lung nodules (14%), lobar collapse/consolidation (8%), pleural effusion (2%), lobar collapse/consolidation (8%), emphysema (6%) and pleural calcification (4%).</p> <p>Conclusions</p> <p>CTPAs requested for the exclusion of PE have a high yield of cardiac abnormalities. Although these abnormalities may not have implications for acute clinical management, they may, nevertheless, be important in long-term care.</p

    Brachydactyly

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    Brachydactyly ("short digits") is a general term that refers to disproportionately short fingers and toes, and forms part of the group of limb malformations characterized by bone dysostosis. The various types of isolated brachydactyly are rare, except for types A3 and D. Brachydactyly can occur either as an isolated malformation or as a part of a complex malformation syndrome. To date, many different forms of brachydactyly have been identified. Some forms also result in short stature. In isolated brachydactyly, subtle changes elsewhere may be present. Brachydactyly may also be accompanied by other hand malformations, such as syndactyly, polydactyly, reduction defects, or symphalangism
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