1,518 research outputs found
Isospin mass splittings of heavy baryons in HQS
In this paper, the electromagnetic mass differences of heavy hadrons are
discussed, while ignoring the relevant hyperfine interactions. The effects of
one-photon exchange interaction and up-down quark mass difference are
parameterized. Two mass difference equations 2\Sigma_c^+ - (\Sigma_c^{++} +
\Sigma_c^0) = 2\Sigma_b^0 - (\Sigma_b^+ + \Sigma_b^-) and (\Xi_{cc}^+ -
\Xi_{cc}^{++}) + (\Xi_{bb}^- - \Xi_{bb}^{0}) =2(\Xi_{bc}^0 - \Xi_{bc}^{+}) for
the heavy baryons are obtained. In addition, the masses of \Sigma_b^0, \Xi_b^0,
and \Xi_{cc}^{++} are predicted based on the known experimental data.Comment: 13 pages, 1 table. one section added. version accepted by Phys.Rev.
A neuronal death model: overexpression of neuronal intermediate filament protein peripherin in PC12 cells
<p>Abstract</p> <p>Background</p> <p>Abnormal accumulation of neuronal intermediate filament (IF) is a pathological indicator of some neurodegenerative disorders. However, the underlying neuropathological mechanisms of neuronal IF accumulation remain unclear. A stable clone established from PC12 cells overexpressing a GFP-Peripherin fusion protein (pEGFP-Peripherin) was constructed for determining the pathway involved in neurodegeneration by biochemical, cell biology, and electronic microscopy approaches. In addition, pharmacological approaches to preventing neuronal death were also examined.</p> <p>Results</p> <p>Results of this study showed that TUNEL positive reaction could be detected in pEGFP-Peripherin cells. Swollen mitochondria and endoplasmic reticulum (ER) were seen by electron microscopy in pEGFP-Peripherin cells on day 8 of nerve growth factor (NGF) treatment. Peripherin overexpression not only led to the formation of neuronal IF aggregate but also causes aberrant neuronal IF phosphorylation and mislocation. Western blots showed that calpain, caspase-12, caspase-9, and caspase-3 activity was upregulated. Furthermore, treatment with calpain inhibitor significantly inhibited cell death.</p> <p>Conclusions</p> <p>These results suggested that the cytoplasmic neuronal IF aggregate caused by peripherin overexpression may induce aberrant neuronal IF phosphorylation and mislocation subsequently trapped and indirectly damaged mitochondria and ER. We suggested that the activation of calpain, caspase-12, caspase-9, and caspase-3 were correlated to the dysfunction of the ER and mitochondria in our pEGFP-Peripherin cell model. The present study suggested that pEGFP-Peripherin cell clones could be a neuronal death model for future studies in neuronal IFs aggregate associated neurodegeneration.</p
Curvature effect induce topological phase transitions in two dimensional topological superconductor
Recently, topological superconductor is one of the important topics in
condensed matter physics due to the exotic features of quasiparticles resided
on the edge, surface and vortex core. In our work, we analyze the two
dimensional s+p wave noncentrosymmetric superconductor(NCS) with Rashba
spin-orbit coupling in 2D cylindrical coordinate to find the relationship
between the topological phase transition and the curvature. With analytical
calculation and numerical analyze, we confirm that the topological phase
transition in s+p wave NCS in 2D cylindrical coordinate is related to the
curvature from band theory perspective.Comment: 9 pages, 2 figure
Disseminated nocardiosis with thyroid involvement: A case report
Nocardiosis is a life-threatening infection that affects the lungs, skin, and central nervous system, particularly in immune-compromised patients. We report a case of disseminated nocardiosis with pneumonia, brain abscesses, meningitis, and thyroiditis, for an individual with recent steroid therapy. Recovery was uneventful with a 4-month course of sulfamethoxazole–trimethoprim
Fluoroquinolone therapy for bloodstream infections caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae
AbstractBackground/PurposeFor extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae infections, carbapenems are recommended as first line therapy, and clinical data on the therapeutic efficacy of fluoroquinolones (FQs) is limited. This study compares the efficacy of FQs and carbapenems for bloodstream infections caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae.MethodsBetween 2008 and 2010, adults with ESBL-producing E. coli or K. pneumoniae bacteremia at two medical centers were reviewed. Adults receiving definitive FQ or carbapenem therapy were compared in a propensity score-matched analysis, and 30-day mortality was the primary endpoint.ResultsA total of 299 patients were eligible. Patients receiving a FQ (n = 24), either ciprofloxacin or levofloxacin, had a lower 30-day mortality rate than those with carbapenem therapy (8.3%, 2/24 vs. 23.3%, 64/275; p = 0.12). Multivariate regression analysis revealed that a critical illness [Pitt bacteremia score ≥ 4 points; odds ratio (OR), 7.09; p < 0.001], rapidly fatal underlying disease (OR, 5.73; p < 0.001), and hospital-associated infection (OR, 2.57; p = 0.01) were independently associated with 30-day mortality. By contrast, FQ definitive therapy was a protective factor compared with carbapenems (OR, 0.18; p = 0.04). There were 72 matched cases with carbapenem therapy in a propensity score-matched analysis, and a difference in the 30-day mortality rate of two groups was noted (8.3% vs. 29.2%; p = 0.05).ConslusionFor ESBL-producing E. coli or K. pneumoniae bacteremia, ciprofloxacin or levofloxacin, if active in vitro, can be considered as a carbapenem-sparing alternative
Combination of Treadmill Aerobic Exercise with Bifidobacterium longum OLP-01 Supplementation for Treatment of High-Fat Diet-Induced Obese Murine Model
Introduction: Obesity, which can result from disease, genetics, nutrition, lifestyle, and insufficient physical activity, substantially increases an individual’s risk of complications and comorbidities. Exercise can be an effective strategy for achieving an energy balance and physiological fitness as part of obesity management. Additionally, probiotics, which are isolated from food and the environment, are being rapidly developed and have functional benefits for mitigating various metabolic dysfunctions associated with obesity. The potentially positive physiological and functional effects of exercise, probiotics, and exercise combined with probiotics should be elucidated in a model of diet-induced obesity. Methods: Bifidobacterium longum subsp. longum OLP-01 (OLP-01) was isolated from an elite Olympic-level athlete who exhibited physiological adaptations to peripheral fatigue caused by exercise training. In this current study, ICR strain mice were fed a high-fat diet (HFD) for 4 weeks to replicate an obesity model. The mice were divided into 5 groups according to the diet administered: control with normal diet, only HFD, HFD + exercise, HFD + OLP, and HFD + exercise + OLP groups. They were administered the probiotic and/or treadmill exercise training for 5 weeks, and their growth curve, physical activity, physiological adaptation, biochemical parameters, body composition, and glucose tolerance were assessed. Results: Compared with only exercise or only probiotics, a combination of probiotics and exercise significantly improved the weight, glucose tolerance, fat composition, and exercise-related oxidative stress of mice. Regular and programmed exercise with sufficient rest may be crucial to obesity improvement, and a combination of probiotics and exercise may synergistically assist obesity management and health promotion. Conclusion: OLP-01 probiotics combined with exercise training can be employed as a strategy for treating obesity. However, the exact regulatory mechanisms underlying this effect, possibly involving microbiota and associated metabolites, warrant further investigation
Changes in the Nasal Colonization with Methicillin-Resistant Staphylococcus aureus in Children: 2004-2009
BACKGROUND: Staphylococcus aureus is an important cause of infection, particularly in persons colonized with this organism. This study compared the annual prevalence and microbiological characteristics of methicillin-resistant S. aureus (MRSA) nasal colonization in Taiwanese children from 2004 through 2009. Risk factors for MRSA were determined for the overall study period. METHODS: Children from birth to ≤14 years of age presenting for health maintenance visits or attending 1 of 57 kindergartens were recruited. Nasal swabs were obtained, and a questionnaire was administered. The prevalence and microbiological characteristics of MRSA colonization were also calculated for two 3-year periods: 2004-2006 and 2007-2009. RESULTS: Cultures of the anterior nares were positive for S. aureus in 824 (25.8%) of the 3,200 children, and MRSA colonization was found in 371 (11.6%) children. The prevalence of S. aureus colonization decreased from 28.1% in 2004-2006 to 23.3% in 2007-2009 (p<0.01), whereas the prevalence of MRSA colonization increased from 8.1% to 15.1% during this period (p<0.0001). Multivariate analysis revealed that the independent risk factors for MRSA carriage were different for male and female children, and also among age groups. Most MRSA isolates belonged to sequence type 59 (ST59) (86.3%); however, a multiresistant MRSA clone with ST338 background emerged in 2007-2009. Ten (62.5%) of the 16 MRSA isolates expressed the genotypic profile ST338/staphylococcal cassette chromosome mec V(T)/Panton-Valentine leukocidin-positive/staphylococcal enterotoxin B-positive, and differed only in their antimicrobial susceptibility patterns. CONCLUSION: The prevalence of nasal colonization by MRSA increased among healthy Taiwanese children from 2004-2006 to 2007-2009, despite an overall decrease in the prevalence of nasal colonization by S. aureus. A multiresistant MRSA clone characterized as ST338 was identified from these children
Community-onset bacteremia in kidney transplant recipients: The recipients fare well in terms of mortality and kidney injury
BackgroundBloodstream infection is not uncommon in kidney transplant recipients (KTRs) and is associated with mortality, graft loss, and increased medical expenses. Whether these septic patients are more vulnerable to serious complications, resistant strains, or worse clinical outcomes than other patient groups in the community-onset settings remains undetermined.MethodsA retrospective study was conducted at a medical center in southern Taiwan. Community-onset bacteremia in the KTRs and a control population at the emergency department were identified. Demographic data, clinical characteristics, bacteremic pathogens, antimicrobial resistance, and clinical outcomes were recorded.ResultsForty-one bacteremic episodes in the KTRs and 82 episodes in control patients were studied. The KTR group had younger age, fewer malignancies, more urosepsis (61% vs. 22%, p = 0.004), and fewer biliary tract infections (0% vs. 13.4%, p = 0.018). Escherichia coli was the most commonly isolated pathogen in both the groups (51.2% and 41.5%, respectively). No Klebsiella pneumoniae bacteremia was noted in the KTRs, compared with 14 (17.1%) episodes in the control group (p = 0.010). Antimicrobial resistance profiles of bacteremic pathogens were similar (all p > 0.6). The KTRs with community-onset bacteremia did not have a worse outcome (in-hospital mortality rate: 2.4% vs. 10%, p = 0.172) nor more incomplete resolution of kidney injury after acute kidney injury events (21.1% vs. 25%, p > 0.99) than the control group.ConclusionKTRs with community-onset bacteremia did not fare worse in terms of clinical outcome and kidney injury
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