191 research outputs found

    Psychological disorders inwomen with spontaneous preterm delivery

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    Background: Preterm delivery is a major cause of mortality in infants. The prevalence of preterm delivery is rising over time. Psychological disorders have been associated with preterm delivery. In this study, we aimed to compare the frequency of psychological disorders among women with spontaneous preterm versus term delivery. Methods: In this cross-sectional study, psychological disorders in 60 women, who experienced spontaneous term delivery and in 60 women who had spontaneous preterm delivery (gestational age of less than 37 weeks) were examined, using symptom checklist-90-revised questionnaire (SCL-90-R) in Akbarabadi teaching hospital during 2014. The question scales were compared between the two groups, using Chi 2 test and independent t-test. Results: The mean age of the participants was 23.58±4.26, and 23.90±4.71 in preterm-delivery and term-delivery groups, respectively (P value = 0.22). The mean score of Symptom checklist-90-revised questionnaire (SCL-90-R) was 102.21 (±35.81) in women with preterm delivery, and it was 59.14±22.17 in women with term delivery, which was significantly different (P value < 0.001). In addition, the total score and the score for all the subscales of psychological disorder were higher in women with preterm delivery (P value < 0.001). Conclusions: Psychological disorders in pregnancy are associated with an increased risk of preterm delivery. Therefore, future studies should focus on finding ways to lower psychological disorders in late pregnancy. © 2016, Shiraz University of Medical Sciences

    Heat treatment of cold-sprayed C355 Al for repair: microstructure and mechanical properties

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    Cold gas dynamic spraying of commercially pure aluminum is widely used for dimensional repair in the aerospace sector as it is capable of producing oxide-free deposits of hundreds of micrometer thickness with strong bonding to the substrate, based on adhesive pull-off tests, and often with enhanced hardness compared to the powder prior to spraying. There is significant interest in extending this application to structural, load-bearing repairs. Particularly, in the case of high-strength aluminum alloys, cold spray deposits can exhibit high levels of porosity and microcracks, leading to mechanical properties that are inadequate for most load-bearing applications. Here, heat treatment was investigated as a potential means of improving the properties of cold-sprayed coatings from Al alloy C355. Coatings produced with process conditions of 500 °C and 60 bar were heat-treated at 175, 200, 225, 250 °C for 4 h in air, and the evolution of the microstructure and microhardness was analyzed. Heat treatment at 225 and 250 °C revealed a decreased porosity (~ 0.14% and 0.02%, respectively) with the former yielding slightly reduced hardness (105 versus 130 HV0.05 as-sprayed). Compressive residual stress levels were approximately halved at all depths into the coating after heat treatment, and tensile testing showed an improvement in ductility

    Harnessing metastability for grain size control in multiprincipal element alloys during additive manufacturing

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    Controlling microstructure in fusion-based metal additive manufacturing (AM) remains a challenge due to numerous parameters directly impacting solidification conditions. Multiprincipal element alloys (MPEAs) offer a vast compositional design space for microstructural engineering due to their chemical complexity and exceptional properties. Here, we establish a novel alloy design paradigm in MPEAs for AM using the FeMnCoCr system. By exploiting the decreasing phase stability with increasing Mn content, we achieve notable grain refinement and breakdown of columnar grain growth. We combine thermodynamic modeling, operando synchrotron X-ray diffraction, multiscale microstructural characterization, and mechanical testing to gain insight into the solidification physics and its ramifications on the resulting microstructure. This work paves way for tailoring grain sizes through targeted manipulation of phase stability, thereby advancing microstructure control in AM

    An amorphous silicon photodiode array for glass-based optical MEMS application

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    A highly sensitive photo-detector array deposited on a glass substrate with an optional integrated optical filter have been presented. The active element is a vertically integrated hydrogenated amorphous silicon photodiode featuring a dark current of less than 1e-10 A/cm2 for -3V polarization and a maximal quantum efficiency of 80% near 580 nm. The prototype was encapsulated and successfully tested optically. It has a fill factor of only 44% which, however, can be easily increased to 90% using flip-chip bonding to an integrated electronic circuit for signal conditioning. The sensor is biocompatible and can be integrated with other glass-based and glass compatible micro-fabricated devices such as optical, microfluidic, lab-on-a-chip, chemical and biological devices in which photo-detection is a desired feature. ©2009 IEEE

    Protective effect of cerium oxide nanoparticle on sperm quality and oxidative damage in malathioninduced testicular toxicity in rats: An experimental study

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    Background: Malathion is an organophosphorus pesticide that commonly used in many agricultural and non-agricultural processes. Previous studies have reported the effects of melatonin on the reproductive system. Cerium dioxide nanoparticles (CeNPs) due to their antioxidative properties are promising to impact on the development of male infertility. Objective: The aim of this study was to evaluate the effect of CeNPs on oxidative stress and sperm parameters after malathion exposure of male rats. Materials and Methods: 36 adult male Wistar rats were divided into 6 groups (n=6/each): Control, CeNPs -treated control (15 and 30 mg/kg/day), malathion (100 mg/ kg/day), and CeNPs -treated malathion groups (15 and 30 mg/ kg/day). At the end of the study (4 wk), the sperm counts, motility, and viability in the testis of rats were measured, also lipid peroxidation, total antioxidant capacity, and total thiol groups in homogenate testis were investigated. Results: Malathion significantly reduced sperm count, viability, and motility than the control rats (p<0.001). Co-treatment of malathion with CeNPs 30 mg/kg had a protective effect on sperm counts (p=0.03), motility (p=0.01), and viability (p<0.001) compare to malathion group. Also, the results showed that malathion reduced testis total anti-oxidant capacity, the total thiol group, and increased testis malondialdehyde than the control rats (p<0.001). CeNPs 30 mg/kg are increased total antioxidant capacity (p<0.001) and total thiol group (p=0.03) compared to malathion group. CeNPs at both doses (15 and 30 mg/kg) improved malondialdehyde than the malathion group (p<0.001 and p=0.01 respectively). Conclusion: CeNPs 30 mg/kg administered considerably restored testicular changes induced by malathion. The improvement of oxidative stress by CeNPs may be associated with increased sperm counts, motility and viability in the testis. © 2018, Research and Clinical Center for Infertitlity. All rights reserved

    Auto Calibration and Optimization of Large-Scale Water Resources Systems

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    Water resource systems modelling have constantly been a challenge through history for human being. As the innovative methodological development is evolving alongside computer sciences on one hand, researches are likely to confront more complex and larger water resources systems due to new challenges regarding increased water demands, climate change and human interventions, socio-economic concerns, and environment protection and sustainability. In this research, an automatic calibration scheme has been applied on the Gilan's large-scale water resource model using mathematical programming. The water resource model's calibration is developed in order to attune unknown water return flows from demand sites in the complex Sefidroud irrigation network and other related areas. The calibration procedure is validated by comparing several gauged river outflows from the system in the past with model results. The calibration results are pleasantly reasonable presenting a rational insight of the system. Subsequently, the unknown optimized parameters were used in a basin-scale linear optimization model with the ability to evaluate the system's performance against a reduced inflow scenario in future. Results showed an acceptable match between predicted and observed outflows from the system at selected hydrometric stations. Moreover, an efficient operating policy was determined for Sefidroud dam leading to a minimum water shortage in the reduced inflow scenario

    Dilated Virchow-Robin spaces are a marker for arterial disease in multiple sclerosis

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    BACKGROUND Virchow-Robin spaces (VRS) have been associated with neurodegeneration and neuroinflammation. However, it remains uncertain to what degree non-dilated or dilated VRS reflect specific features of neuroinflammatory pathology. Thus, we aimed at investigating the clinical relevance of VRS as imaging biomarker in multiple sclerosis (MS) and to correlate VRS to their histopathologic signature. METHODS In a cohort study comprising 142 MS patients and 30 control subjects, we assessed the association of non-dilated and dilated VRS to clinical and magnetic resonance imaging (MRI) outcomes. Findings were corroborated in a validation cohort comprising 63 MS patients. Brain blocks from 6 MS patients and 3 non-MS controls were histopathologically processed to correlate VRS to their tissue substrate. FINDINGS In our actively treated clinical cohort, the count of dilated centrum semiovale VRS was associated with increased T1 and T2 lesion volumes. There was no systematic spatial colocalization of dilated VRS with MS lesions. At tissue level, VRS mostly corresponded to arteries and were not associated with MS pathological hallmarks. Interestingly, in our ex vivo cohort comprising mostly progressive MS patients, dilated VRS in MS were associated with signs of small vessel disease. INTERPRETATION Contrary to prior beliefs, these observations suggest that VRS in MS do not associate with an accumulation of immune cells. But instead, these findings indicate vascular pathology as a driver and/or consequence of neuroinflammatory pathology for this imaging feature. FUNDING NIH, Swedish Society for Medical Research, Swiss National Science Foundation and University of Zurich
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