1,011 research outputs found

    Theoretical studies of the first-row transition metal phosphides

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    B3LYP calculations were performed with an extended basis set on the first-row TM phosphides. It was found that the ground states of these phosphides follow those of the isoelectronic sulfides. In addition, the covalent character of these phosphides increase across the series from Sc to Cu, in accordance with the electronegativity difference.published_or_final_versio

    Ge quantum dot arrays grown by ultrahigh vacuum molecular beam epitaxy on the Si(001) surface: nucleation, morphology and CMOS compatibility

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    Issues of morphology, nucleation and growth of Ge cluster arrays deposited by ultrahigh vacuum molecular beam epitaxy on the Si(001) surface are considered. Difference in nucleation of quantum dots during Ge deposition at low (<600 deg C) and high (>600 deg. C) temperatures is studied by high resolution scanning tunneling microscopy. The atomic models of growth of both species of Ge huts---pyramids and wedges---are proposed. The growth cycle of Ge QD arrays at low temperatures is explored. A problem of lowering of the array formation temperature is discussed with the focus on CMOS compatibility of the entire process; a special attention is paid upon approaches to reduction of treatment temperature during the Si(001) surface pre-growth cleaning, which is at once a key and the highest-temperature phase of the Ge/Si(001) quantum dot dense array formation process. The temperature of the Si clean surface preparation, the final high-temperature step of which is, as a rule, carried out directly in the MBE chamber just before the structure deposition, determines the compatibility of formation process of Ge-QD-array based devices with the CMOS manufacturing cycle. Silicon surface hydrogenation at the final stage of its wet chemical etching during the preliminary cleaning is proposed as a possible way of efficient reduction of the Si wafer pre-growth annealing temperature.Comment: 30 pages, 11 figure

    Minim Typing – A Rapid and Low Cost MLST Based Typing Tool for Klebsiella pneumoniae

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    Here we report a single nucleotide polymorphism (SNP) based genotyping method for Klebsiella pneumoniae utilising high-resolution melting (HRM) analysis of fragments within the multilocus sequence typing (MLST) loci. The approach is termed mini-MLST or Minim typing and it has previously been applied to Streptococcus pyogenes, Staphylococcus aureus and Enterococcus faecium. Six SNPs were derived from concatenated MLST sequences on the basis of maximisation of the Simpsons Index of Diversity (D). DNA fragments incorporating these SNPs and predicted to be suitable for HRM analysis were designed. Using the assumption that HRM alleles are defined by G+C content, Minim typing using six fragments was predicted to provide a D = 0.979 against known STs. The method was tested against 202 K. pneumoniae using a blinded approach in which the MLST analyses were performed after the HRM analyses. The HRM-based alleles were indeed in accordance with G+C content, and the Minim typing identified known STs and flagged new STs. The tonB MLST locus was determined to be very diverse, and the two Minim fragments located herein contribute greatly to the resolving power. However these fragments are refractory to amplification in a minority of isolates. Therefore, we assessed the performance of two additional formats: one using only the four fragments located outside the tonB gene (D = 0.929), and the other using HRM data from these four fragments in conjunction with sequencing of the tonB MLST fragment (D = 0.995). The HRM assays were developed on the Rotorgene 6000, and the method was shown to also be robust on the LightCycler 480, allowing a 384-well high through-put format. The assay provides rapid, robust and low-cost typing with fully portable results that can directly be related to current MLST data. Minim typing in combination with molecular screening for antibiotic resistance markers can be a powerful surveillance tool kit

    A randomized controlled trial reporting functional outcomes of cognitive-behavioural therapy in medication‑treated adults with ADHD and comorbid psychopathology

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    Studies assessing psychological treatment of attention deficit hyperactivity disorder (ADHD) in adults are increasingly reported. However, functional outcomes are often neglected in favour of symptom outcomes. We investigated functional outcomes in 95 adults with ADHD who were already treated with medication and randomized to receive treatment as usual (TAU/MED) or psychological treatment (CBT/MED) using a cognitive–behavioural programme, R&R2ADHD, which employs both group and individual modalities. RATE-S functional outcomes associated with ADHD symptoms, social functioning, emotional control and antisocial behaviour were given at baseline, end of treatment and three-month follow-up. The Total composite score of these scales is associated with life satisfaction. In addition, independent evaluator ratings of clinicians who were blind to treatment arm were obtained on the Clinical Global Impression scale at each time point. CBT/MED showed overall (combined outcome at end of treatment and 3-month follow-up) significantly greater functional improvement on all scales. Post-group treatment effects were maintained at follow-up with the exception of emotional control and the Total composite scales, which continued to improve. The largest treatment effect was for the RATE-S Total composite scale, associated with life satisfaction. CGI significantly correlated with all outcomes except for social functioning scale at follow-up. The study provides further evidence for the effectiveness of R&R2ADHD and demonstrates the importance of measuring functional outcomes. The key mechanism associated with improved functional outcomes is likely to be behavioural control

    Expression Analysis of the NLRP Gene Family Suggests a Role in Human Preimplantation Development

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    Background: The NLRP (Nucleotide-binding oligomerization domain, Leucine rich Repeat and Pyrin domain containing) family, also referred to as NALP family, is well known for its roles in apoptosis and inflammation. Several NLRPs have been indicated as being involved in reproduction as well. Methodology: We studied, using the unique human gametes and embryo materials, the expression of the NLRP family in human gametes and preimplantation embryos at different developmental stages, and compared the expression levels between normal and abnormal embryos using real-time PCR. Principal Findings: Among 14 members of the NLRP family, twelve were detected in human oocytes and preimplantation embryos, whereas seven were detected in spermatozoa. Eight NLRPs (NLRP4, 5, 8, 9, 11, 12, 13, and 14) showed a similar expression pattern: their expression levels were high in oocytes and then decreased progressively in embryos, resulting in a very low level in day 5 embryos. However, NLRP2 and NLRP7 showed a different expression pattern: their expression decreased from oocytes to the lowest level by day 3, but increased again by day 5. The expression levels of NLRP5, 9, and 12 were lower in day 1 abnormal embryos but higher in day3 and day5 arrested embryos, when compared with normal embryos at the same stages. NLRP7 was down-regulated in day 1 and day 5 abnormal embryos but over-expressed in day3 arrested embryos

    Determining the neurotransmitter concentration profile at active synapses

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    Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission

    Participation of the PI-3K/Akt-NF-κB signaling pathways in hypoxia-induced mitogenic factor-stimulated Flk-1 expression in endothelial cells

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    BACKGROUND: Hypoxia-induced mitogenic factor (HIMF), a lung-specific growth factor, promotes vascular tubule formation in a matrigel plug model. We initially found that HIMF enhances vascular endothelial growth factor (VEGF) expression in lung epithelial cells. In present work, we tested whether HIMF modulates expression of fetal liver kinase-1 (Flk-1) in endothelial cells, and dissected the possible signaling pathways that link HIMF to Flk-1 upregulation. METHODS: Recombinant HIMF protein was intratracheally instilled into adult mouse lungs, Flk-1 expression was examined by immunohistochemistry and Western blot. The promoter-luciferase reporter assay and real-time RT-PCR were performed to examine the effects of HIMF on Flk-1 expression in mouse endothelial cell line SVEC 4–10. The activation of NF-kappa B (NF-κB) and phosphorylation of Akt, IKK, and IκBα were examined by luciferase assay and Western blot, respectively. RESULTS: Intratracheal instillation of HIMF protein resulted in a significant increase of Flk-1 production in lung tissues. Stimulation of SVEC 4–10 cells by HIMF resulted in increased phosphorylation of IKK and IκBα, leading to activation of NF-κB. Blocking NF-κB signaling pathway by dominant-negative mutants of IKK and IκBα suppressed HIMF-induced Flk-1 upregulation. Mutation or deletion of NF-κB binding site within Flk-1 promoter also abolished HIMF-induced Flk-1 expression in SVEC 4–10 cells. Furthermore, HIMF strongly induced phosphorylation of Akt. A dominant-negative mutant of PI-3K, Δp85, as well as PI-3K inhibitor LY294002, blocked HIMF-induced NF-κB activation and attenuated Flk-1 production. CONCLUSION: These results suggest that HIMF upregulates Flk-1 expression in endothelial cells in a PI-3K/Akt-NF-κB signaling pathway-dependent manner, and may play critical roles in pulmonary angiogenesis

    Right Paraduodenal Hernia in an Adult Patient: Diagnostic Approach and Surgical Management

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    Paraduodenal hernia, a rare congenital anomaly which arises from an error of rotation of the midgut, is the most common type of intraabdominal hernia. There are two variants, right and left paraduodenal hernia, the right being less common. We report the case of a 41-year-old patient with a right paraduodenal hernia with a 6-month history of intermittent episodes of intestinal obstruction. Diagnosis was established by CT scan and upper gastrointestinal series with small bowel follow-through. In a planned laparotomy, herniation of the small bowel loops through the fossa of Waldeyer was found. Division of the lateral right attachments of the colon opened the hernia sac widely, replacing the pre- and postarterial segments of the intestine in the positions they would normally occupy at the end of the first stage of rotation during embryonic development. Six months after the surgery, after an uneventful recovery, the patient remains free of symptoms
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