33 research outputs found

    A note on D-brane Interactions in the IIA Plane-Wave Background

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    We compute the D-brane tensions in the type IIA plane-wave background by comparing the interaction potential between widely separated D-branes in string theory with the supergravity mode exchange between the D-branes. We found that the D-brane tensions and RR charges in the plane-wave background are the same as those in the flat space. Also we work out the stringy halo behavior of the DpDpˉDpD\bar{p} spacelike branes and find the explicit dependence on the light cone separation r+r^+. This suggests that the detailed tachyon dynamics for the spacelike DpDpˉDpD\bar{p} branes are different from those in the flat space case. We also discuss specific features of the exchange amplitudes in relation to the geometric properties of the IIA plane wave background. When branes are located at focal points, full or partial restoration of the translation invariance occurs and the amplitudes are similar to those in the flat space.Comment: 19 pages; discussions on the integrated amplitudes in geometric terms adde

    Joint Identification of Genetic Variants for Physical Activity inKorean Population

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    Abstract: There has been limited research on genome-wide association with physical activity (PA). This study ascertained genetic associations between PA and 344,893 single nucleotide polymorphism (SNP) markers in 8842 Korean samples. PA data were obtained from a validated questionnaire that included information on PA intensity and duration. Metabolic equivalent of tasks were calculated to estimate the total daily PA level for each individual. In addition to single- and multiple-SNP association tests, a pathway enrichment analysis was performed to identify the biological significance of SNP markers. Although no significant SNP was found at genome-wide significance level via single-SNP association tests, 59 genetic variants mapped to 76 genes were identified via a multiple SNP approach using a bootstrap selection stability measure. Pathway analysis for these 59 variants showed that maturity onset diabetes of the young (MODY) was enriched. Joint identification of SNPs could enable the identification of multiple SNPs with good predictive power for PA and a pathway enriched for PA

    Differential Proteome Profiling Using iTRAQ in Microalbuminuric and Normoalbuminuric Type 2 Diabetic Patients

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    Diabetic nephropathy (DN) is a long-term complication of diabetes mellitus that leads to end-stage renal disease. Microalbuminuria is used for the early detection of diabetic renal damage, but such levels do not reflect the state of incipient DN precisely in type 2 diabetic patients because microalbuminuria develops in other diseases, necessitating more accurate biomarkers that detect incipient DN. Isobaric tags for relative and absolute quantification (iTRAQ) were used to identify urinary proteins that were differentially excreted in normoalbuminuric and microalbuminuric patients with type 2 diabetes where 710 and 196 proteins were identified and quantified, respectively. Some candidates were confirmed by 2-DE analysis, or validated by Western blot and multiple reaction monitoring (MRM). Specifically, some differentially expressed proteins were verified by MRM in urine from normoalbuminuric and microalbuminuric patients with type 2 diabetes, wherein alpha-1-antitrypsin, alpha-1-acid glycoprotein 1, and prostate stem cell antigen had excellent AUC values (0.849, 0.873, and 0.825, resp.). Moreover, we performed a multiplex assay using these biomarker candidates, resulting in a merged AUC value of 0.921. Although the differentially expressed proteins in this iTRAQ study require further validation in larger and categorized sample groups, they constitute baseline data on preliminary biomarker candidates that can be used to discover novel biomarkers for incipient DN

    The effectiveness of Paxlovid treatment in long-term care facilities in South Korea during the outbreak of the Omicron variant of SARS-CoV-2

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    Objectives On November 5, 2021, Pfizer Inc. announced Paxlovid (nirmatrelvir+ritonavir) as a treatment method that could reduce the risk of hospitalization or death for patients with confirmed coronavirus disease 2019 (COVID-19). Methods From February 6, 2022 to April 2, 2022, the incidence of COVID-19 and the effects of treatment with Paxlovid were analyzed in 2,241 patients and workers at 5 long-term care facilities during the outbreak of the Omicron variant of severe acute respiratory syndrome coronavirus 2 in South Korea. Results The rate of severe illness or death in the group given Paxlovid was 51% lower than that of the non-Paxlovid group (adjusted risk ratio [aRR], 0.49; 95% confidence interval [CI], 0.24−0.98). Compared to unvaccinated patients, patients who had completed 3 doses of the vaccine had a 71% reduced rate of severe illness or death (aRR, 0.29; 95% CI, 0.13−0.64) and a 65% reduced death rate (aRR, 0.35; 95% CI, 0.15−0.79). Conclusion Patients given Paxlovid showed a lower rate of severe illness or death and a lower fatality rate than those who did not receive Paxlovid. Patients who received 3 doses of the vaccine had a lower rate of severe illness or death and a lower fatality rate than the unvaccinated group

    Changes in liver stiffness values assessed using transient elastography in chronic hepatitis B patients treated with tenofovir disoproxil fumarate: a prospective observational study

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    Background/Aims Regression of liver fibrosis during antiviral therapy in chronic hepatitis B (CHB) patients has been demonstrated, but data on the influence of long-term treatment with tenofovir disoproxil fumarate (TDF) on liver stiffness (LS) measured by transient elastography are scarce. We aimed to investigate the changes in LS values during the 144-week TDF therapy in treatment-naïve CHB patients. Methods This prospective observational study was conducted from April 2015 to July 2020 at CHA Bundang Medical Center. Laboratory tests and LS measurements were performed at baseline and repeated at weeks 12, 24, 48, 96, and 144. A significant decline in LS was defined as ≥ 30% decrease in LS value at week 96 from baseline. Results A total of 48 treatment-naïve CHB patients initiating TDF therapy were screened, and 36 patients were included in the final analysis (median age, 46 [interquartile range, 34.5–55.8] years; 19 men [52.8%]). During TDF therapy, the median LS values decreased from 13.8 kPa at baseline to 8.7 kPa, 6.5 kPa, and 6.4 kPa at weeks 48, 96, and 144, respectively (all P < 0.001). At week 96, virological and biochemical responses were achieved in 34 (94.4%) patients and 20 (76.9%) patients, respectively. Moreover, 21 of 36 (58.3%) patients showed a significant decline in LS value. A higher baseline LS value was a single independent predictor for the reduction in LS value at week 96 from baseline (P < 0.001). Conclusions During the 144-week TDF therapy, LS values declined significantly in treatment-naïve CHB patients.This study was supported by Gilead Sciences. None of the funding sources had any role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publicatio

    Determining crystal structures through crowdsourcing and coursework

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    We show here that computer game players can build high-quality crystal structures. Introduction of a new feature into the computer game Foldit allows players to build and real-space refine structures into electron density maps. To assess the usefulness of this feature, we held a crystallographic model-building competition between trained crystallographers, undergraduate students, Foldit players and automatic model-building algorithms. After removal of disordered residues, a team of Foldit players achieved the most accurate structure. Analysing the target protein of the competition, YPL067C, uncovered a new family of histidine triad proteins apparently involved in the prevention of amyloid toxicity. From this study, we conclude that crystallographers can utilize crowdsourcing to interpret electron density information and to produce structure solutions of the highest quality

    hep-th/0306282 Boundary States in IIA Plane-Wave Background

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    We work out boundary states for Type IIA string theory on a plane wave background. By directly utilizing the channel duality, the induced conditions from the open string boundary conditions are imposed on the boundary states. The resulting boundary states correctly reproduce the partition functions of the open string theory for DpDp and DpD¯p cases where Dp branes are half BPS brane if located at the origin of the plane wave background

    Analysis of pregnant women with critically severe COVID-19 in Korea from February 2020 and December 2021

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    Objectives This study aimed to describe the characteristics and risk factors for severe disease in pregnant women infected with coronavirus disease 2019 (COVID-19) from the early days of the COVID-19 epidemic in Korea to the predominant period of the Delta variant. Methods A retrospective cohort study was conducted among pregnant women diagnosed with COVID-19 between February 2020 and December 2021. Logistic regression analysis was performed to compare severe and mild cases after adjusting for pregnant women’s age, nationality, infection route, outbreak area, infection period, symptoms, underlying disease, smoking status, trimester, and COVID-19 vaccination status. Results In total, 2,233 pregnant women were diagnosed with COVID-19 by December 2021. Among these, 96.7% had mild symptoms, 3.3% had severe symptoms, and 0.04% died. The risk factors for severe disease in pregnant women with confirmed COVID-19 were being in the age group of 35 to 45 years, having hyperlipidemia, being in the second or third trimester of pregnancy at the time of COVID-19 diagnosis, being infected during the Delta-predominant period, and having a fever (≥38 °C) at diagnosis. Furthermore, 47.1% of patients in the mild group and 84.9% of patients in the severe group had 3 or more risk factors. Conclusion Pregnant women with COVID-19 mainly experienced mild symptoms, but those with risk factors were at a higher risk of developing severe symptoms. Therefore, treatment and follow-up management should be thoroughly implemented

    Near-Infrared Spectroscopic Analysis for Classification of Water Molecules in Wood by a Theory of Water Mixtures

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    This study was conducted to analyze the mechanism of moisture adsorption-desorption in wood using near-IR (NIR) spectroscopy. NIR spectra reflected from moist wood were acquired, and spectra in the range from 1800-2100 nm, which were sensitive to water variation, were decomposed into three different components according to the Buijs and Choppin theory. It is assumed that the three components represent three types of bound water: water molecules without -OH groups engaged in hydrogen bonds (S0), water molecules with one -OH group engaged in a hydrogen bond (S1), and water molecules with two -OH groups engaged in hydrogen bonds (S2). Ratios of the decomposed spectra of NIR absorbed by each type of water molecule were analyzed during changes in water adsorption-desorption states. Through this analysis, a sorption model for predicting the structural state of each water component in wood was constructed. This model may be used to explain the effect of each water component on the occurrence of hysteresis as well as the transient state between bound water and free water. Based on the model, it was concluded that the monomolecular water layer in yellow poplar wood formed below approximately 8% MC during adsorption. Additionally, the phenomenon of hysteresis was demonstrated by the difference between the ratios of the S2 components in desorption and adsorption
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