Holographic QCD for H-dibaryon (uuddss)

The H-dibaryon (uuddss) is studied in holographic QCD for the first time. In holographic QCD, four-dimensional QCD, i.e., SU($N_c$) gauge theory with chiral quarks, can be formulated with $S^1$-compactified D4/D8/$\overline{\rm D8}$-brane system. In holographic QCD with large $N_c$, all the baryons appear as topological chiral solitons of Nambu-Goldstone bosons and (axial) vector mesons, and the H-dibaryon can be described as an SO(3)-type topological soliton with $B=2$. We derive the low-energy effective theory to describe the H-dibaryon in holographic QCD. The H-dibaryon mass is found to be twice of the $B=1$ hedgehog-baryon mass, $M_{\rm H} \simeq 2.00 M_{B=1}^{\rm HH}$, and is estimated about 1.7GeV, which is smaller than mass of two nucleons (flavor-octet baryons), in the chiral limit.Comment: 6 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1610.0047

A Study of the H-dibaryon in Holographic QCD

We study the H-dibaryon (uuddss) in holographic QCD for the first time. Holographic QCD is derived from a QCD-equivalent D-brane system ($S^1$-compactified D4/D8/$\overline{\rm D8}$) in the superstring theory via the gauge/gravity correspondence. In holographic QCD, all baryons appear as topological chiral solitons of Nambu-Goldstone bosons and (axial) vector mesons. In this framework, the H-dibaryon can be described as an SO(3)-type hedgehog state. We present the formalism of the H-dibaryon in holographic QCD, and perform the calculation to investigate its properties in the chiral limit.Comment: 5 pages, 2 figure

1+1 Large NcN_c QCD and its Holographic Dual -Soliton Picture of Baryons in Single-Flavor World

We study baryons in holographic QCD corresponding to 1+1 dimensional single-flavor ($N_f$=1) QCD for the first time. We formulate 1+1 QCD using an $S^1$-compactified D2/D8/$\overline{\rm D8}$ branes in the superstring theory, and describe the baryon as a topological configuration in 1+1 $N_f$=1 QCD, corresponding to $\Pi_1({\rm U(1)})={\bf Z}$. Unlike 1+3 QCD with $N_f \ge 2$, however, we find that the low-dimensional baryonic soliton is generally unstable against a scale transformation/variation and swells infinitely in 1+1 $N_f$=1 QCD at the leading of large $N_c$. We thus point out a serious difficulty on the soliton picture of baryons in large $N_c$ in the single-flavor world in both 1+1 and 1+3 QCD. We also compare the low-dimensional holographic baryon with the Abrikosov vortex, i.e., a stable topological configuration in Type-II superconductors.Comment: 5 pages, 3 figure

Time evolution of a thin black ring via Hawking radiation

Black objects lose their mass and angular momenta through evaporation by Hawking radiation, and the investigation of their time evolution has a long history. In this paper, we study this problem for a five-dimensional doubly spinning black ring. The black ring is assumed to emit only massless scalar particles. We consider a thin black ring with a small thickness parameter, $\lambda\ll 1$, which can be approximated by a boosted Kerr string locally. We show that a thin black ring evaporates with fixing its thickness parameter $\lambda$. Further, in the case of an Emparan-Reall black ring, we derive analytic formulas for the time evolution, which has one parameter to be evaluated numerically. We find that the lifetime of a thin black ring is shorter by a factor of $O(\lambda^2)$ compared to a five-dimensional Schwarzschild black hole with the same initial mass. We also study detailed properties of the Hawking radiation from the thin black ring, including the energy and angular spectra of emitted particles.Comment: 28 pages, 6 figure

Tropical calcific pancreatitis.........An overview

Tropical calcific pancreatitis is a nonalcoholic type of chronic pancreatitis affecting the childrens and young adults characterized clinically by recurrent abdominal pain in childhood, diabetes in adolescent and death in early childhood. Although the exact etiology is not known, malnutrition and chronic cassava toxicity either singly or in combination are presumed to be the prime factor in pancreatic injury unopposed by detoxification of free radical. Moreover micronutrients deficiency, oxidant stress and antioxidant deficiency might play substantial role. Diabetes secondary to tropical calcific pancreatitis is a distinctive and frequent problem, being named by W.H.O. study group as 'fibrocalculous pancreatic diabetes (FCPD) and classified as one of the variant of the so-called malnutrition related diabetes mellitus (MRDM).熱帯地方の貧困層の小児や若干成人にみられる非アルコール性の慢性膵炎で,小児期に反復する腹痛で発症し,10～20歳で膵性糖尿病になり,20～ 30歳で死亡する類似の病像を示す症例をTropical calcific pancreatitis(熱帯性石灰化慢性膵炎)という｡高率に膵石を伴う｡成因は乳幼児期からの熱量,蛋白貰,micronutrients(亜鉛,銅,セレニウム)の摂取不足に加えて食事中シアン産生物質や環境中oxidantsなど複合因子によると推測されている｡病理像は世界各国にみられる慢性膵炎典型例に類似する｡最近は,生活環境や医療事情の改善により,全身栄養障害の減少や生存期間 の延長など病像が変貌しっつある｡糖尿病を重視する立場からはFibrocalculous pancreatic diabetesと呼ばれ,同一地域にみられるProtein-deficient pancreatic diabetesと合わせてMalnutrition-related diabetes mellitus(MRDM)と総称し,糖尿病の一亜型に分類されている

Hip fracture protection by alendronate treatment in postmenopausal women with osteoporosis: a review of the literature

Osteoporosis most commonly affects postmenopausal women, placing them at a significant risk of fractures. In particular, hip fractures are an important cause of mortality and morbidity among postmenopausal women. Anti-resorptive therapies that produce greater decreases in bone turnover markers together with greater increases in bone mineral density (BMD) are associated with greater reductions in fracture risk, especially at sites primarily composed of cortical bone such as the hip. Thus, treatment with potent anti-resorptive drugs like alendronate is a strategy for preventing hip fractures in postmenopausal women with osteoporosis. The purpose of this paper is to discuss the efficacy of alendronate against hip fractures and the mechanism for this anti-fracture efficacy in postmenopausal women with osteoporosis. A meta-analysis of randomized controlled trials has shown that alendronate reduces the risk of hip fractures by 55% in postmenopausal women with osteoporosis. According to the analyses of the Fracture Intervention Trial, each 1 standard deviation reduction in a 1-year change in bone-specific alkaline phosphatase (BSAP) is associated with 39% fewer hip fractures in alendronate-treated postmenopausal women, and those with at least 30% reduction in BSAP have a 74% lower risk of hip fractures relative to those with less than 30%. Alendronate is effective in reducing the risk of hip fractures across a spectrum of ages. The mechanism for this anti-fracture efficacy has been clarified; alendronate strongly suppresses bone turnover and subsequently increases hip BMD, decreases cortical porosity, improves parameters of hip structure geometry (cortical thickness, cross-sectional area, section modulus, and buckling ratio), and produces more uniform mineralization (increases the mean degree of mineralization of bone) in cortical bone. A once-weekly regimen of alendronate administration provides better patient compliance and persistence with the treatment than the once-daily dosing regimen, leading to greater efficacy against hip fractures. Thus, the efficacy of alendronate against hip fractures has been confirmed in postmenopausal women with osteoporosis, especially with a once-weekly dosing regimen