270 research outputs found

    Line Defects in Molybdenum Disulfide Layers

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    Layered molecular materials and especially MoS2 are already accepted as promising candidates for nanoelectronics. In contrast to the bulk material, the observed electron mobility in single-layer MoS2 is unexpectedly low. Here we reveal the occurrence of intrinsic defects in MoS2 layers, known as inversion domains, where the layer changes its direction through a line defect. The line defects are observed experimentally by atomic resolution TEM. The structures were modeled and the stability and electronic properties of the defects were calculated using quantum-mechanical calculations based on the Density-Functional Tight-Binding method. The results of these calculations indicate the occurrence of new states within the band gap of the semiconducting MoS2. The most stable non-stoichiometric defect structures are observed experimentally, one of which contains metallic Mo-Mo bonds and another one bridging S atoms

    Millennials and Masculinity: A Shifting Tide of Gender Typing of ICT?

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    The question of a possible shift in Millennials’ perceptions about gender and ICT resulted from a survey of gender stereotyping of ICT skills among college age Millennials in the USA. The results identify three clusters of skills: masculine (includes computer programming, database and networking); feminine (includes communication, working in teams, ethics, global and cultural awareness, and openness to new experiences) and gender neutral (includes initiative, ability to work under pressure, critical thinking and problem solving). These findings suggest a possible shift of gender stereotypes about ICT skills among Millennials. Nevertheless, the gender stereotyping of the more technical skills in the IT profession as masculine argues for continued interventions to alter these perceptions and expand the gender neutral space in order to broaden the participation of women in the IT field

    Should patients with kearns-sayre syndrome and corneal endothelial failure be genotyped for a TCF4 trinucleotide repeat, commonly associated with fuchs endothelial corneal dystrophy?

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    The aim of this study was to describe the ocular phenotype in a case with Kearns-Sayre syndrome (KSS) spectrum and to determine if corneal endothelial cell dysfunction could be attributed to other known distinct genetic causes. Herein, genomic DNA was extracted from blood and exome sequencing was performed. Non-coding gene regions implicated in corneal endothelial dystrophies were screened by Sanger sequencing. In addition, a repeat expansion situated within an intron of TCF4 (termed CTG18.1) was genotyped using the short tandem repeat assay. The diagnosis of KSS spectrum was based on the presence of ptosis, chronic progressive external ophthalmoplegia, pigmentary retinopathy, hearing loss, and muscle weakness, which were further supported by the detection of ~6.5 kb mtDNA deletion. At the age of 33 years, the proband’s best corrected visual acuity was reduced to 0.04 in the right eye and 0.2 in the left eye. Rare ocular findings included marked corneal oedema with central corneal thickness of 824 and 844 µm in the right and left eye, respectively. No pathogenic variants in the genes, which are associated with corneal endothelial dystrophies, were identified. Furthermore, the CTG18.1 genotype was 12/33, which exceeds a previously determined critical threshold for toxic RNA foci appearance in corneal endothelial cells

    Efficient Expression of <i style="box-sizing: border-box;">Igf-1</i> from Lentiviral Vectors Protects <i style="box-sizing: border-box;">In Vitro</i> but Does Not Mediate Behavioral Recovery of a Parkinsonian Lesion in Rats

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    Gene therapy approaches delivering neurotrophic factors have offered promising results in both preclinical and clinical trials of Parkinson's disease (PD). However, failure of glial cell line-derived neurotrophic factor in phase 2 clinical trials has sparked a search for other trophic factors that may retain efficacy in the clinic. Direct protein injections of one such factor, insulin-like growth factor (IGF)-1, in a rodent model of PD has demonstrated impressive protection of dopaminergic neurons against 6-hydroxydopamine (6-OHDA) toxicity. However, protein infusion is associated with surgical risks, pump failure, and significant costs. We therefore used lentiviral vectors to deliver Igf-1, with a particular focus on the novel integration-deficient lentiviral vectors (IDLVs). A neuron-specific promoter, from the human synapsin 1 gene, excellent for gene expression from IDLVs, was additionally used to enhance Igf-1 expression. An investigation of neurotrophic effects on primary rat neuronal cultures demonstrated that neurons transduced with IDLV-Igf-1 vectors had complete protection on withdrawal of exogenous trophic support. Striatal transduction of such vectors into 6-OHDA-lesioned rats, however, provided neither protection of dopaminergic substantia nigra neurons nor improvement of animal behavior

    Effects of Ebola epidemic on obstetrical emergencies and outcomes in the region of Kindia, Guinea

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    Background: Maternal mortality is still high in Guinea despite a decline from 724 to 550 maternal deaths per 100,000 live births between 2012 and 2018. The proportion of births attended by skilled personnel is estimated at 45%. The objective of this study was to assess the effect of Ebola virus disease (EVD) epidemic on the frequency of absolute maternal indications, as well as the outcomes of these interventions for mother and child in the region of Kindia.Methods: This was a longitudinal study using 20 months of retrospective data collected in the pre-Ebola (March to December 2012 and March to December 2013) and intra-Ebola (March to December 2014 and March to December 2015) periods. The proportions of maternal health indicators in both study periods were compared using a significance level of 0.05.Results: A total of 1747 women were included in this study. The proportion of women who received a major obstetric procedure in Kindia regional hospital was 85% in each pre and post Ebola periods. Ebola, however, contributed to a significant increase in maternal deaths.Conclusions: The Ebola epidemic has contributed to a significant increase in maternal deaths in health facilities. Measures encouraging health workers to manage obstetric emergencies during critical periods would be necessary

    Identification of genetic variants by whole genome sequencing in Ankamali pigs of Kerala

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    Ankamali pig is a domesticated native variety of Kerala which is well known for its disease resistance, lean meat and adaptability to hot tropical environments. Recent breakthrough in genome sequencing technologies have created unparalleled prospects to characterize individual genomic landscapes and identifying mutations between and within populations. The current study aims to determine the genetic variations in Ankamali pigs using whole genome sequencing. The GATK HaplotypeCaller was used to identify the variants. There were over 26 million (26,604,589) single nucleotide variants (SNVs), including more than 21 million SNPs and over 5 million indels. In Ankamali pigs, the total genome length obtained was more than 2.5 billion with an average variant rate of one variant in every 94 bases. The significance of different variant rate on 18 chromosomes were analysed using the chi-square statistics. The variant rates in Sus scrofa chromosomes10 and 13 were significantly different (p<0.01%) in Ankamali pigs. The significantly higher variable rate on chromosome 10 was observed with one variant per 64 bases. Whereas, significantly lower variable rate was observed on chromosome 13, with one variant in every 122 bases. The variant rate reported on Sus scrofa chromosome 12 (SSC12) was also significantly higher (p<0.05%), having one variant per 72 bases. The variability of many genes and QTLs associated with several haematological traits and meat quality traits located on these chromosomes may contribute the phenotypic and genetic uniqueness of Ankamali animals

    Types, obstacles and sources of empowerment in co-design: the role of shared material objects and processes

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    Co-design is intrinsically linked to the notion of empowerment, however little research has focussed specifically on understanding the types, obstacles and sources of empowerment in co-design. This paper combines theoretical investigations with observations derived from co-designed research by academic and non-academic partners to explore these issues, in particular, the role of shared material objects and processes in supporting empowerment during co-design. The paper uses the notions of ‘power over,’ ‘power to’, ‘power with’ and ‘power within’ to tease out different aspects of empowerment, and draws on empirical observations to determine different obstacles and sources associated with each. The study therefore makes a theoretical contribution to the understanding of co-design as an empowerment process and should be useful for design researchers undertaking co-design projects with non-experts

    W Doping in Ni12P5as a Platform to Enhance Overall Electrochemical Water Splitting

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    Bifunctional electrocatalysts for efficient hydrogen generation from water splitting must overcome both the sluggish water dissociation step of the alkaline hydrogen evolution half-reaction (HER) and the kinetic barrier of the anodic oxygen evolution half-reaction (OER). Nickel phosphides are a promising catalysts family and are known to develop a thin active layer of oxidized Ni in an alkaline medium. Here, Ni12P5 was recognized as a suitable platform for the electrochemical production of γ-NiOOH-a particularly active phase-because of its matching crystallographic structure. The incorporation of tungsten by doping produces additional surface roughness, increases the electrochemical surface area (ESCA), and reduces the energy barrier for electron-coupled water dissociation (the Volmer step for the formation of Hads). When serving as both the anode and cathode, the 15% W-Ni12P5 catalyst provides an overall water splitting current density of 10 mA cm-2 at a cell voltage of only 1.73 V with good durability, making it a promising bifunctional catalyst for practical water electrolysis. © 2021 American Chemical Society.S.G. and S.K. thank the financial support of the Kreitman Post- Doctoral fellowship at the BGU. This center of excellence was supported by The Israel Science Foundation (grant no. 1212/21)

    Plasmonic nanofillers-enabled solar membrane crystallization for mineral recovery

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    Recently, the excitation of localized surface plasmon resonances in metal nanoparticles (NPs) has been exploited in membrane science (especially, membrane distillation) to overcome temperature polarization. However, the prohibitive costs of state-of-the-art plasmonic NPs such as Ag and Au have opened the quest of alternative materials. Here, we show that nanoscale photothermal effects activated by light irradiation on nanocomposite membranes made of a thin microporous coating of polydimethylsiloxane (PDMS) loaded with NiSe or CoSe NPs supported on polyvinylidene fluoride might be exploited to achieve crystallization of dissolved salts in brines. Explicitly, we demonstrate that the embodiment of the plasmonic NiSe and CoSe NPs is capable to originate an increase of the vaporization of the water from brine once the nanocomposite membranes are irradiated with sunlight, with the possibility to reach the supersaturation conditions, with the subsequent heterogeneous nucleation and crystallization of dissolved salts. © 2023Ministry of Science and Technology, MOST; Ministero degli Affari Esteri e della Cooperazione Internazionale, MAECIAP and MBS acknowledge the IVANHOE project funded by the Ministero degli Affari Esteri e della Cooperazione Internazionale (MAECI) for Italy and Ministry of Science and Technology (MOST) for Israel. DWB acknowledges research funding from Jiangsu Innovative and Entrepreneurial Talents Project
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