267 research outputs found

    Supersymmetric Matrix model on Z-orbifold

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    We find that the IIA Matrix models defined on the non-compact C3/Z6C^3/Z_6, C2/Z2C^2/Z_2 and C2/Z4C^2/Z_4 orbifolds preserve supersymmetry where the fermions are on-mass-shell Majorana-Weyl fermions. In these examples supersymmetry is preserved both in the orbifolded space and in the non-orbifolded space at the same time. The Matrix model on C3/Z6C^3/Z_6 orbifold has the same N=2{\cal N}=2 supersymmetry as the case of C3/Z3C^3/Z_3 orbifold which was pointed out previously. On the other hand the Matrix models on C2/Z2C^2/Z_2 and C2/Z4C^2/Z_4 orbifold have a half of the N=2{\cal N}=2 supersymmetry. We further find that the Matrix model on C2/Z2C^2/Z_2 orbifold with a parity-like identification preserves N=2{\cal N}=2 supersymmetry.Comment: 21 pages, no figur

    Dona Mariana:Una historia de vida de la mujer maya

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    Gross E esophageal atresia with unique course

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    The patient was a 15 months-old boy who had been diagnosed CHARGE syndrome, which is a multiple congenital anomaly syndrome caused by mutations in the CHD7 gene. Mechanical ventilation management was initiated 2 hours after birth for dysphagia and respiratory failure, and tracheotomy was performed 3 months after birth for dysphagia and failed extubation. He was repeatedly hospitalized due to pneuomoniae. Approximately 1 year after birth, the boy had two consecutive episodes of sudden ventilatory insufficiency while replacing the tracheotomy cannula. A bronchoscopic examination under general anesthesia revealed a tracheoesophageal fistula directly below the tracheostomy. The patient was diagnosed with Gross E esophageal atresia, and we speculated that the cannula migrated to the esophagus via the fistula during tracheostomy cannula replacement. Gross E esophageal atresia is a rare disease. Its diagnosis is often delayed, and it is discovered by recurrent pneumonia in many cases. A tracheoesophageal fistula may also be found in children with deformities of the respiratory system. Furthermore, tracheoesophageal fistulae are often found in the neck. Therefore, when sudden ventilatory insufficiency occurs in a child with a tracheostomy after replacing the tracheostomy cannula, caution must be exercised since the cannula may have migrated to the esophagus via a fistula

    NMR verification of Dirac nodal lines in a single-component molecular conductor

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    The Dirac nodal line (DNL) is a novel form of massless Dirac fermions that reside along lines in momentum space. Here, we verify genuine DNLs in the molecular material, [Ni(dmdt)2_2], with the combined NMR experiments and numerical simulations. The NMR spectral shift and spin-lattice relaxation rate divided by temperature, 1/T1T1/T_1T, decrease linearly and quadratically with temperature, respectively, and become constant at low temperatures, consistent with slightly dispersive DNLs with small Fermi pockets. Comparison of these results with model simulations of DNLs reveals the suppression of the Fermi velocity and the enhancement of antiferromagnetic fluctuations due to electron correlation as well as the influence of the Landau quantization. The present study offers a demonstration to identify the DNL and evaluate the correlation effect with NMR.Comment: 6 pages, 3 figure

    Direct Action of Celastrol on Hypothalamic ARC Neurons to Increase Leptin Sensitivity

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    Leptin is an adipocyte-derived hormone that is involved in the regulation of food intake and energy expenditure. Individuals with obesity generally exhibit hyperleptinemia and leptin resistance. Leptin sensitizers, rather than leptin, are expected to act as anti-obesity drugs. Recently, celastrol was identified as a leptin sensitizer. Celastrol alleviated endoplasmic reticulum (ER) stress and restored leptin sensitivity in the hypothalamus. However, the molecular mechanisms and sites of action of celastrol remain poorly understood. In this study, after confirming the effect of celastrol on body weight, food intake, and leptin sensitivity in lean and diet-induced obese (DIO) mice, we investigated the direct effect of celastrol on arcuate nucleus (ARC) neurons isolated from the hypothalamus by monitoring the intracellular calcium concentrations ([Ca2+]i). Celastrol treatment significantly decreased body weight gain and food intake, and significantly augmented leptin actions on food intake and hypothalamic signal transducer and activator of transcription 3 (STAT3) phosphorylation in both lean and DIO mice. In accordance with these results, celastrol treatment enhanced [Ca2+]i response to leptin in the ARC neurons of both lean and DIO mice. To our knowledge, this is the first report to demonstrate the direct effect of celastrol on ARC neurons. This knowledge might shed light on the molecular mechanisms underlying celastrol-induced leptin sensitization and resistance.departmental bulletin pape

    Evaluation of the immunotoxicity potential of nanomaterials using THP-1 cells

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    With the expansion of nanomaterials (NMs) usage, concerns about their toxicity are increasing, and the wide variety of NMs makes it difficult to assess their toxicity. Therefore, the development of a high-throughput, accurate, and certified method to evaluate the immunotoxicity of NMs is required. In this study, we assessed the immunotoxicity potential of various NMs, such as nanoparticles of silver, silica, and titanium dioxide, using the human Cell Line Activation Test (h-CLAT) at the cellular level. After exposure to silver nanoparticle dispersions, the expression levels of CD86 and CD54 increased, suggesting the activation of antigen-presenting cells (APCs) by silver nanoparticles. Quantification of silver ions eluted from silver nanoparticles and the activation of APCs by silver ions suggested that it was due to the release of silver ions. Silica nanoparticles also increased the expression of CD86 and/or CD54, and their activation ability correlated with the synthesis methods and hydrodynamic diameters. The ability of titanium dioxide to activate APCs differed depending on the crystal type and hydrodynamic diameter. These results suggest a potential method to evaluate the immunotoxicity potential of various NMs based on their ability to activate APCs using human monocytic THP-1 cells. This method will be valuable in assessing the immunotoxicity potential and elucidating the immunotoxic mechanisms of NMs

    Burnout among kindergarten teachers and associated factors

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    Burnout among kindergarten teachers is a subject of great concern. Although burnout is reported to be significantly associated with turnover intention and work engagement, few studies have examined factors associated with burnout among these teachers. Therefore, in the present study, we performed a cross-sectional survey of burnout and associated factors among kindergarten teachers. We distributed 3363 questionnaires to all 205 authorized kindergartens and childcare institutions in Nagasaki Prefecture and received 1086 responses (response rate: 32.3%). The participants were limited to full-time female class teachers. After excluding survey forms with incomplete content, we ultimately examined valid responses from 442 participants. The survey examined burnout (Maslach Burnout Inventory, MBI), teacher stress (Nursery Teacher’s Stress Scale, NTSS), coping behaviors (Brief Scales for Coping Profile, BSCP), and social support (Social Support Scale, SSS). A multiple regression analysis revealed that all 3 MBI subscales were positively associated with “understanding of how to handle children” on the NTSS and negatively associated with “superiors” on the SSS. “Emotional exhaustion” was significantly associated with “interpersonal relations at work” and “lack of time” on the NTSS, and “avoidance and suppression” on the BSCP. “Depersonalization” was significantly associated with age, “disconnect in working conditions” on the NTSS, and “proactive problem solving” and “venting emotions to others” on the BSCP. “Diminished professional accomplishment” was significantly associated with age, “lack of time” on the NTSS, and “proactive problem solving” and “change in perspective” on the BSCP. These results suggest that support from superiors that enables teachers to better understand children and handle them appropriately is necessary to prevent burnout

    Pituitary Adenylate Cyclase-Activating Polypeptide Protects Glomerular Podocytes from Inflammatory Injuries

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    Diabetic nephropathy (DN) is a leading cause of end-stage kidney disease; however, there are few treatment options. Inflammation plays a crucial role in the initiation and/or progression of DN. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide, which was originally isolated from the ovine hypothalamus and reportedly has diverse biological functions. It has been reported that PACAP has renoprotective effects in different models of kidney pathology. However, the specific cell types within the kidney that are protected by PACAP have not yet been reported. In this study, we localized VPAC1, one of the PACAP receptors, to glomerular podocytes, which also reportedly has crucial roles not only in glomerular physiology but also in pathology. PACAP was effective in the downregulation of proinflammatory cytokines, such as monocyte chemoattractant protein-1 (MCP-1) and interleukin-6, which had been induced by the activation of toll-like receptor (TLR) with lipopolysaccharide. PACAP also had downregulated the expression of MCP-1 through the protein kinase A signaling pathway; this led to the attenuation of the activation of extracellular signal-regulated kinase and nuclear factor-kappa B signaling. Our results suggested that PACAP could be a possible treatment option for DN through the use of anti-inflammation effects on glomerular podocytes
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