849 research outputs found

    U-Spin Symmetry in Charmless B Decays

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    We prove a general theorem about equal CP rate differences within pairs of U-spin related charmless BB and BsB_s decays. Large deviations from equalities would be evidence for new physics. Six pairs of decays into two pseudoscalar mesons are identified where such relations hold. Ratios of corresponding rate differences and certain ratios of rates measure U-spin breaking. These processes provide useful information on the weak phase γ=ArgVub∗\gamma={\rm Arg} V^*_{ub}. Applications of U-spin symmetry to other decays are discussed.Comment: A few typos corrected, to appear in Phys. Lett.

    Studying New Physics Amplitudes in Charmless B_s Decays

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    A method based on flavour SU(3) is proposed for identifying and extracting New Physics (NP) amplitudes in charmless ΔS=1\Delta S=1 BsB_s decays using time-dependent CP asymmetries in these decays and in flavour SU(3) related ΔS=0\Delta S=0 decays. For illustration, we assume a hierarchy, ∌1:λ:λ2\sim 1: \lambda : \lambda^2 (λ=0.2\lambda=0.2), between a dominant ΔS=1\Delta S=1 penguin amplitude, a NP amplitude and a Standard Model amplitude with weak phase Îł\gamma. An uncertainty from SU(3) breaking corrections, reduced by using ratios of hadronic amplitudes, is further suppressed by a factor λ\lambda. We discuss examples for pairs of decays into two neutral vector mesons, Bs→ϕϕ,Bs→ϕKˉ∗0B_s\to\phi\phi, B_s\to\phi \bar K^{*0} and Bs→K∗0Kˉ∗0,B0→K∗0Kˉ∗0B_s\to K^{*0}\bar K^{*0}, B^0\to K^{*0}\bar K^{*0}, where the magnitude of the NP amplitude, its weak and strong phases can be determined.Comment: typo corrected, reference added, submitted to Physics Letters

    Weak phases γ\gamma and α\alpha from B+B^+, or B0B^0 and BsB_s decays

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    An improved flavor SU(3) method is presented for determining the weak angle Îł\gamma of the unitarity triangle using decay rates for B+→Kπ,B+→K+Kˉ0B^+\to K\pi, B^+\to K^+\bar K^0 and B+→π+ηB^+\to \pi^+\eta (or B0→KπB^0\to K\pi and Bs→KπB_s\to K \pi), their CP-conjugate modes and the CP-averaged rate for B±→π±π0B^\pm\to\pi^\pm\pi^{0}. Rescattering (color-suppressed) contribution in B+(B0)→KπB^+(B^0)\to K\pi, for which an improved bound is obtained, is subtracted away. The only significant SU(3) breaking effects are accounted for in the factorization approximation of tree amplitudes. The weak angle α\alpha is obtained as a byproduct.Comment: 9 pages with 2 included eps figures; revised argument, taking into account the special shape of the amplitude quadrangle. An improved bound on rescattering effects is give

    Acyclovir Nephrotoxicity: A Case Report Highlighting the Importance of Prevention, Detection, and Treatment of Acyclovir-Induced Nephropathy

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    Acute kidney injury is an unfortunate complication of acyclovir therapy secondary to crystal-induced nephropathy. It is characterized by a decrease in renal function that develops within 24–48 hours of acyclovir administration indicated by a rapid rise in the serum creatinine. Failure to quickly realize this as an etiology of acute kidney injury can lead to excessive morbidity to the patient. The case described in this vignette is an example of the clinical manifestation of acyclovir crystal obstructive nephrotoxicity. We will briefly discuss the pathophysiology, diagnosis, prevention, and management of patients that present with acyclovir nephrotoxicity

    Quantification of sirolimus by liquid chromatography-tandem mass spectrometry using on-line solid-phase extraction

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    Quantification of the new immunosuppressant sirolimus (syn. rapamycin; Rapamune((R))) in whole blood by chromatography is essential for its clinical use since no immunoassay is available although monitoring is mandatory. Here we report on a rapid and convenient liquid chromatography (LC)-tandem mass spectrometry method and describe our practical experience with its routine use. Whole blood samples were hemolyzed and deproteinized using an equal volume (150 mul) of a mixture of methanol/zinc sulfate solution containing the internal standard desmethoxy-rapamycin. After centrifugation, the clear supernatants were submitted to an on-line solid-phase extraction procedure using the polymeric Waters Oasis HLB(R) material, with elution of the extracts onto the analytical column in the back-flush mode by column switching. For analytical chromatography a RP-C18 column was used with 90/10 methanol/2 mM ammonium acetate as the mobile phase. A 1:10 split was used for the transfer to the mass spectrometer, a Micromass Quattro LC-tandem mass spectrometry system equipped with a Z-spray((R)) source and used in the positive electrospray ionization mode. The following transitions were recorded: sirolimus, 931>864 m/z, and desmethoxy-rapamycin (I.S.), 901>834 m/z. The analytical running time was 5 min, including on-line extraction. The method has a linear calibration curve (r>0.99; range 1.6-50 mug/l) and is rugged and precise with monthly CVs <7% at a sirolimus concentration of 13.1 mug/l in routine use; the instrumentation proved to be reliable and required minimal maintenance

    Prenatal Human Immunodeficiency Virus Testing and Patient Management by Obstetricians in a High Seroprevalence Community

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    Objective: In order to determine the practice habits of obstetricians concerning frequency of prenatal human immunodeficiency virus (HIV) testing and management strategies for HIV-seropositive obstetric patients, we conducted a telephone survey of practicing obstetricians over a 3-month period

    Organising product stewardship in large chemical companies

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    The paper analyses the organisation of Environmental, Health and Safety (EHS) management in the chemicals manufacturing industry, focussing in particular on the implementation of the “Responsible Care” framework and the concept of “Product Stewardship”. We conduct in depth interviews with two major manufacturers of speciality chemicals regarding their overall strategy with respect to product safety, the organisational structure of their EHS management, the decision processes involved in product development and their Product Stewardship management systems. The efficiency of centralised versus decentralised organisational structures for achieving product safety are discussed and suggestions are given how the incentives of companies to efficiently implement and follow Product Stewardship guidelines can be enhanced

    The Role of Bs→KπB_s \to K \pi in Determining the Weak Phase Îł\gamma

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    The decay rates for B0→K+π−B^0 \to K^+ \pi^-, B+→K0π+B^+ \to K^0 \pi^+, and the charge-conjugate processes were found to provide information on the weak phase γ≡Arg(Vub∗)\gamma \equiv {\rm Arg}(V_{ub}^*) when the ratio rr of weak tree and penguin amplitudes was taken from data on B→ππB \to \pi \pi or semileptonic B→πB \to \pi decays. We show here that the rates for Bs→K−π+B_s \to K^- \pi^+ and Bˉs→K+π−\bar B_s \to K^+ \pi^- can provide the necessary information on rr, and estimate the statistical accuracy of forthcoming measurements at the Fermilab Tevatron.Comment: 8 pages, LaTeX, no figures, submitted to Physics Letters B, corrections to discussion of SU(3) breaking adde
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