Charmless B→PV,VVB \to PV, VV decays and new physics effects in the mSUGRA model

By employing the QCD factorization approach, we calculate the new physics contributions to the branching radios of the two-body charmless $B \to PV$ and $B \to VV$ decays in the framework of the minimal supergravity (mSUGRA) model. we choose three typical sets of the mSUGRA input parameters in which the Wilson coefficient $C_{7\gamma}(m_b)$ can be either SM-like (the case A and C) or has a flipped-sign (the case B). We found numerically that (a) the SUSY contributions are always very small for both case A and C; (b) for those tree-dominated decays, the SUSY contributions in case B are also very small; (c) for those QCD penguin-dominated decay modes, the SUSY contributions in case B can be significant, and can provide an enhancement about $30$ to the branching ratios of $B \to K^*(\pi,\phi,\rho)$ and $K \phi$ decays, but a reduction about $30$ to $B\to K(\rho, \omega)$ decays; and (d) the large SUSY contributions in the case B may be masked by the large theoretical errors dominated by the uncertainty from our ignorance of calculating the annihilation contributions in the QCD factorization approach.Comment: 34 pages, 8 PS figures, this is the correct version

Electronic structure of Ca1−x_{1-x}Srx_xVO3_3: a tale of two energy-scales

We investigate the electronic structure of Ca$_{1-x}$Sr$_x$VO$_3$ using photoemission spectroscopy. Core level spectra establish an electronic phase separation at the surface, leading to distinctly different surface electronic structure compared to the bulk. Analysis of the photoemission spectra of this system allowed us to separate the surface and bulk contributions. These results help us to understand properties related to two vastly differing energy-scales, namely the low energy-scale of thermal excitations (~$k_{B}T$) and the high-energy scale related to Coulomb and other electronic interactions.Comment: 4 pages and 3 figures. Europhysics Letters (appearing

Oxidation mechanisms of ZRB2-based ultra high temperature ceramic matrix composites

Ultra-high temperature ceramics (UHTCs) are expected as the materials for the nose cones and leading edges for hypersonic and re-entry vehicles. Zirconium diboride (ZrB2) and its composites are a widely studied class of UHTCs. The oxidation of monolithic ZrB2 forms ZrO2 and B2O3. B2O3 acts as a surface protective layer; however, it evaporates above 1200℃. SiC particles are considered effective additives because the SiO2 formed by the oxidation of SiC protects the unreacted region. Simultaneously, excessive pores are formed under the surface in the SiC particle-dispersed ZrB2 matrix (hereafter denoted ZS) composites in a wide temperature range by the preferential oxidation of SiC (active oxidation of SiC) because solid SiO2 is not formed; instead, gaseous SiO forms by active oxidation because of the low oxygen partial pressure relative to that of the surface. The pore-rich porous layer is denoted the “SiC-depleted layer”. The SiC-depleted layer leads to spallation and delamination of the oxidized regions on the surface because strength and stiffness of this layer are quite low. Thus, excessive pore formation in ZS composites should be prevented to improve the oxidation resistance. The objective of this study is to understand oxidation mechanisms of ZrB2-based composites and to propose the way to prevent the formation of SiC-depleted layer in ZS composites. In the present study, we fabricated monolithic ZrB2, ZS, and ZrB2-SiC-ZrC (ZSZ) ternary composites by spark plasma sintering (SPS) technique. In addition, carbon fiber-reinforced ZSZ matrix (C/ZSZ) composites was also fabricated by Si melt infiltration (MI) process. Oxidation resistance of monolithic ZrB2, ZS, ZSZ, and C/ZSZ have specially designed fast heating system in order to characterize oxidation resistance above 2000℃. Please click Additional Files below to see the full abstract

Bias amplification in the g-computation algorithm for time-varying treatments: a case study of industry payments and prescription of opioid products

BACKGROUND: It is often challenging to determine which variables need to be included in the g-computation algorithm under the time-varying setting. Conditioning on instrumental variables (IVs) is known to introduce greater bias when there is unmeasured confounding in the point-treatment settings, and this is also true for near-IVs which are weakly associated with the outcome not through the treatment. However, it is unknown whether adjusting for (near-)IVs amplifies bias in the g-computation algorithm estimators for time-varying treatments compared to the estimators ignoring such variables. We thus aimed to compare the magnitude of bias by adjusting for (near-)IVs across their different relationships with treatments in the time-varying settings. METHODS: After showing a case study of the association between the receipt of industry payments and physicians' opioid prescribing rate in the US, we demonstrated Monte Carlo simulation to investigate the extent to which the bias due to unmeasured confounders is amplified by adjusting for (near-)IV across several g-computation algorithms. RESULTS: In our simulation study, adjusting for a perfect IV of time-varying treatments in the g-computation algorithm increased bias due to unmeasured confounding, particularly when the IV had a strong relationship with the treatment. We also found the increase in bias even adjusting for near-IV when such variable had a very weak association with unmeasured confounders between the treatment and the outcome compared to its association with the time-varying treatments. Instead, this bias amplifying feature was not observed (i.e., bias due to unmeasured confounders decreased) by adjusting for near-IV when it had a stronger association with the unmeasured confounders (≥0.1 correlation coefficient in our multivariate normal setting). CONCLUSION: It would be recommended to avoid adjusting for perfect IV in the g-computation algorithm to obtain a less biased estimate of the time-varying treatment effect. On the other hand, it may be recommended to include near-IV in the algorithm unless their association with unmeasured confounders is very weak. These findings would help researchers to consider the magnitude of bias when adjusting for (near-)IVs and select variables in the g-computation algorithm for the time-varying setting when they are aware of the presence of unmeasured confounding

Cold Dark Matter Candidate in a Class of Supersymmetric Models with an Extra U(1)

In supersymmetric models whose gauge group includes an additional U(1) factor at the TeV scale, broken by the VEV of an standard model singlet S, the parameter space can accommodate a very light neutralino not ruled out experimentally. This higgsino-like fermion, stable if R-parity is conserved, can make a good cold dark matter candidate. We examine the thermal relic density of this particle and discuss the prospects for its direct detection if it forms part of our galactic halo.Comment: 13 pages, LaTex, uses psfig.sty with 3 figure

Impact of population aging on trends in diabetes prevalence : A meta-regression analysis of 160,000 Japanese adults

Aims/IntroductionTo provide age- and sex-specific trends, age-standardized trends, and projections of diabetes prevalence through the year 2030 in the Japanese adult population. Materials and MethodsIn the present meta-regression analysis, we included 161,087 adults from six studies and nine national health surveys carried out between 1988 and 2011 in Japan. We assessed the prevalence of diabetes using a recorded history of diabetes or, for the population of individuals without known diabetes, either a glycated hemoglobin level of 6.5% (48mmol/mol) or the 1999 World Health Organization criteria (i.e., a fasting plasma glucose level of 126mg/dL and/or 2-h glucose level of 200mg/dL in the 75-g oral glucose tolerance test). ResultsFor both sexes, prevalence appeared to remain unchanged over the years in all age categories except for men aged 70years or older, in whom a significant increase in prevalence with time was observed. Age-standardized diabetes prevalence estimates based on the Japanese population of the corresponding year showed marked increasing trends: diabetes prevalence was 6.1% among women (95% confidence interval [CI] 5.5-6.7), 9.9% (95% CI 9.2-10.6) among men, and 7.9% (95% CI 7.5-8.4) among the total population in 2010, and was expected to rise by 2030 to 6.7% (95% CI 5.2-9.2), 13.1% (95% CI 10.9-16.7) and 9.8% (95% CI 8.5-12.0), respectively. In contrast, the age-standardized diabetes prevalence using a fixed population appeared to remain unchanged. ConclusionsThis large-scale meta-regression analysis shows that a substantial increase in diabetes prevalence is expected in Japan during the next few decades, mainly as a result of the aging of the adult population.Peer reviewe

Spontaneous esophageal perforation within a hiatal hernia : A case report

Introduction: Spontaneous esophageal perforation, also commonly referred to as Boerhaave's syndrome, is one of the most lethal diseases causing an acute abdomen. Though rare, emergent surgical intervention is often required and management can be various based upon the site of the perforation. This literature has been written in line with the SCARE criteria (Agha et al., 2020) [1]. Presentation of case: A 76-year-old man presented with acute abdominal pain. Computed tomography (CT) revealed and an emergent esophagogastroduodenoscopy (EGD) was performed carefully, which revealed a 7 cm all-layer esophageal laceration in the left lower esophageal wall. In our case, a hiatal hernia was protruding into the mediastinum, and the perforation site was inside of it, but there was no invasion into the thoracic cavity, thus a transabdominal approach was performed without thoracotomy. Discussion: This type of esophageal perforation within a hiatal hernia is quite rare and provides a unique clinical challenge. In addition, A review reported the average length of spontaneous esophageal perforation to be around 2 cm while our case had a perforation with a length of 7 cm. We chose the combination of the simple suture with omental buttress and wide drainage, but a complete fundoplication was impossible due to its large size of perforation. Conclusion: We chose the open abdominal approach because the case had high inflammation, a hiatal hernia and possibility of retro-gastric perforation. However, MIS should have been considered first if a situation or human resources allow it

Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a powerful tool that enables the simultaneous detection and identification of biomolecules in analytes. MALDI-imaging mass spectrometry (MALDI-IMS) is a two-dimensional MALDI-mass spectrometric technique used to visualize the spatial distribution of biomolecules without extraction, purification, separation, or labeling of biological samples. MALDI-IMS has revealed the characteristic distribution of several biomolecules, including proteins, peptides, amino acids, lipids, carbohydrates, and nucleotides, in various tissues. The versatility of MALDI-IMS has opened a new frontier in several fields such as medicine, agriculture, biology, pharmacology, and pathology. MALDI-IMS has a great potential for discovery of unknown biomarkers. In this review, we describe the methodology and applications of MALDI-IMS for biological samples