Universal extra dimensions on real projective plane

We propose a six-dimensional Universal Extra Dimensions (UED) model compactified on a real projective plane RP²${\mathit{RP}}^2$, a two-sphere with its antipodal points being identified. We utilize the Randjbar-Daemi–Salam–Strathdee spontaneous sphere compactification with a monopole configuration of an extra UX₍₁₎$U{(1)}_X$ gauge field that leads to a spontaneous radius stabilization. Unlike the sphere and the S²/Z₂$S^2/Z_2$ orbifold compactifications, the massless UX₍₁₎$U{(1)}_X$ gauge boson is safely projected out. We show how a compactification on a non-orientable manifold results in a chiral four-dimensional gauge theory by utilizing 6D chiral gauge and Yukawa interactions. The resultant Kaluza–Klein mass spectra are distinct from the ordinary UED models compactified on torus. We briefly comment on the anomaly cancellation and also on a possible dark matter candidate in our model.     

Cost-effective production policy for a stochastic unreliable manufacturing system

^** Email: dohi{at}rel.hiroshima-u.ac.jp The paper deals with an economic manufacturing quantity (EMQ)problem for an unreliable manufacturing system in both continuous-and discrete-time settings. The time to machine failure andcorrective and preventive repair times of the production facilityare assumed to follow arbitrary probability distributions. Thetraditional method of determining the EMQ policy for a failure-pronemanufacturing system is based on the minimization of the long-runaverage cost in the steady state. In this paper, an alternativecriterion of optimality called cost effectiveness is introduced.The criteria for the existence and uniqueness of the optimalproduction time maximizing the cost effectiveness are derivedanalytically under general failure and specific repair (correctiveand preventive) time distributions. The optimal cost-effectiveand average cost production policies are numerically calculatedand compared in terms of their performances.     

The synthesis of head-to-tail (H-T) dimers of 3-substituted thiophenes by the hypervalent iodine(III)-induced oxidative biaryl coupling reaction

The head-to-tail (H-T) dimers could be obtained selectively by the oxidative coupling reaction of 3-substituted thiophenes using a combination of hypervalent iodine(III) reagents and trimethylsilyl trifluoromethanesulfonate.     

Design and synthesis of C3-symmetric Lewis(x) antigen

[structure: see text] C(3)-Symmetric glycoconjugates carrying three equivalent Lewis(X) antigens or beta-lactosides were synthesized from p-nitrophenyl glycosides and trimesic acid via regio- and stereocontrolled glycosylation reactions. An (1)H NMR study has shown that the C(3)-symmetric glycoconjugates soluble in water provide useful probes to investigate the Ca(2+)-dependent Lewis(X)-Lewis(X) association.     

A note on portfolio optimization with path-dependent utility

This paper considers the portfolio selection with preferences depending on the history of the wealth process. The maximization problem of the expected terminal utility consisting of the combination of two kinds of preferences is discussed in a continuous trading setting. Especially we focus on the relationship between the portfolio risk and the goal seeking behavior of the financial agent. The numerical example shows how the risk sensitivity affects the optimal portfolio and the corresponding expected path-dependent utility. Finally, we provide a criterion to choose buy and hold or buy and sell strategies.     

Enantiomeric difference in percutaneous penetration of propranolol through rat excised skin.

The percutaneous penetration of R-(+)- and S-(-)-propranolol (PL) through rat excised skin was investigated in vitro. The flux of S-(-)-PL after application to normal skin was high compared with that of R-(+)-PL. On the other hand, in damaged rat skin, the flux of R-(+)-PL was almost equivalent to that of S-(-)-PL. It is suggested that there is an enantiomeric difference between S-(-)- and R-(+)-PL in terms of penetration through rat stratum corneum.     

Stereoselective glycal fluorophosphorylation: synthesis of ADP-2-fluoroheptose, an inhibitor of the LPS biosynthesis

Heptosides are found in important bacterial glycolipids such as lipopolysaccharide (LPS), the biosynthesis of which is targeted for the development of novel antibacterial agents. This work describes the synthesis of a fluorinated analogue of ADP-L-glycero-beta-D-manno-heptopyranose, the donor substrate of the heptosyl transferase WaaC, which catalyzes the incorporation of this carbohydrate into LPS. Synthetically, the key step for the preparation of ADP-2F-heptose is the simultaneous and stereoselective installation of both the fluorine atom at C-2 and the phosphoryl group at C-1 through a selectfluor-mediated (selectfluor=1-chloromethyl-4-fluorodiazoniabicyclo[2.2.2]octane bis(triflate)) electrophilic addition/nucleophilic substitution involving a heptosylglycal. Therefore, we detail in this article 1) the stereoselective preparation of the key intermediates heptosylglycals, 2) the development of a new fluorophosphorylation procedure allowing an excellent beta-gluco stereoselectivity with "all-equatorial" glycals, 3) the synthesis of the target ADP-2F-heptose, and 4) some comments on the contacts observed between the fluorine atom of the final molecule and the protein in the crystallographic structure of heptosyltransferase WaaC.     

Convenient use of ortho-formylphenyl thioglycoside for regioselective conjugation with glycosyl acceptors towards regioselective 1,2-cis-glycosylation

A facile methodology is proposed for regioselective conjugation between glycosyl donors and acceptors towards the development of regioselective 1,2-cis-glycosylation method. ortho-Formylphenyl 1-thio-β-d-galactopyranoside was regioselectively tethered to methyl α-d-glucopyranoside under acidic condition to furnish an 4,6-O-arylidene acetal-linked conjugate. This conjugate can be readily converted to an ether-linked 4-O- or 6-O-derivative by regioselective cleavage of the acetal ring. In the glycosylation reaction, the ether-linked 4-OH conjugate was found to show excellent 1,2-cis selectivity via an intramolecular 1,9-transfer.     

Effects of aging temperature on G-phase precipitation and ferrite-phase decomposition in duplex stainless steel

G-phase precipitation and ferrite-phase decomposition in a cast duplex stainless steel (DSS) aged at 623–723?K for up to 8000?h were investigated using atom probe tomography (APT). Large sample volume was observed in every APT experiment, which yielded significantly statistical results. The number density of G-phase precipitates tended to be high and their sizes were small at lower aging temperatures. G-phase precipitates grew during prolonged isothermal aging. The concentrations of nickel, silicon, manganese and molybdenum in G-phase precipitates tended to increase as the precipitates grew. Heterogeneous distributions of alloying elements within G-phase precipitates were observed. An interesting positional relationship of G-phase precipitates with dislocations was revealed. Regarding the ferrite-phase decomposition, local chromium concentrations in the ferrite phase varied fast at higher aging temperatures. Good correlation between the variation of local chromium concentrations and aging conditions was revealed, which indicates that the variation can be estimated for arbitrary aging conditions. Representative distances between chromium-enriched and chromium-diluted regions were long at higher aging temperatures. Time exponent of the representative distances of ferrite-phase decomposition as well as the size of G-phase precipitates increased with aging temperatures.