Solid-phase synthesis of disulfide heterodimers of peptides

[structure: see text] The synthesis of the orthogonal disulfide template 1 and its use to synthesize unsymmetrical intermolecular disulfide bond peptides on a solid support are described. Application of template 1 to synthesize bioconjugates of cell permeable moieties based on the disulfide bond is demonstrated.     

Precursor diamagnetism above the superconducting transition in YNi_\mathsf{2}B_\mathsf{2}C

High-resolution SQUID magnetization measurements in a single crystal of YNi₂B₂C around the superconducting transition are reported. The diamagnetic magnetization -M _fl at constant field H as a function of temperature and isothermal magnetization curves -M _fl vs. H are used to derive insights on precursor phenomena approaching the bulk transition temperature K. The precursor diamagnetism is found strongly enhanced with respect to the conventional Ginzburg-Landau value for Gaussian fluctuations and the curves -M _fl vs. H exhibit an upturn with the field and hysteretic effects up to T ^* = 15.4 K. These results are interpreted in terms of a non-zero order parameter in superconducting droplets above the bulk T _c . These droplets are likely to be related to inhomogeneities resulting from small amount of boron to carbon substitutions.Received: 23 April 2003, Published online: 15 October 2003PACS: 74.40.+k Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.) - 74.20.De Phenomenological theories (two-fluid, Ginzburg-Landau, etc.) - 74.25.Ha Magnetic properties     

Asymptotique des approximants de Hermite–Padé quadratiques de la fonction exponentielle et problèmes de Riemann–Hilbert

We describe the asymptotic behavior of the polynomials $\text{p,}\text{q,}\text{r}$ of degree n in type I Hermite–Padé approximation to the exponential function, i.e., $\text{p(z)}\text{e}{}^{\mathrm{?z}}\text{+q(z)+r(z)}\text{e}{}^{\mathrm{z}}\text{=}\text{O}\text{(z}{}^{\mathrm{3n+2}}\text{)}$ as z→0. A steepest descent method for Riemann–Hilbert problems, due to Deift and Zhou, is used to obtain strong uniform asymptotics for the scaled polynomials $\text{p(3nz),}\text{q(3nz),}\text{r(3nz)}$ in every domain of the complex plane. An important role is played by a three-sheeted Riemann surface and certain measures and functions defined on it. To cite this article: A. Kuijlaars et al., C. R. Acad. Sci. Paris, Ser. I 336 (2003).     

Über die endliche Definierbarkeit verallgemeinerter Einheitengruppen. II

Ohne Zusammenfassung     

The MTV experiment: a test of time reversal symmetry using polarized 8Li

The MTV (Mott Polarimetry for T-Violation Experiment) experiment at TRIUMF-ISAC (Isotope Separator and ACcelerator), which aims to achieve the highest precision test of time reversal symmetry in polarized nuclear beta decay by measuring a triple correlation (R-correlation), is motivated by the search for a new physics beyond the Standard Model. In this experiment, the existence of non-zero transverse electron polarization is examined utilizing the analyzing power of Mott scattering from a thin metal foil. Backward scattering electron tracks are measured using a multi-wire drift chamber for the first time. The MTV experiment was commissioned at ISAC in 2009 using an 80 % polarized ⁸Li beam at 10⁷ pps, resulting in 0.1 % statistical precision on the R-parameter in the first physics run performed in 2010. Next generation cylindrical drift chamber (CDC) is now being installed for the future run.     

First experimental determination of the charge radius of 74Rb and its application in tests of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix

Collinear-laser spectroscopy with the bunched-beams technique was used for the study of neutron deficient Rb isotopes, out to (74)Rb (N = Z = 37) at TRIUMF. The measured hyperfine coupling constants of (76,78m)Rb were in agreement with literature values. The nuclear spin of (75)Rb was confirmed to be I = 3/2, and its hyperfine coupling constants were measured for the first time. The mean-square charge radius of (74)Rb was determined for the first time. This result has improved the isospin symmetry breaking correction term used to calculate the Ft value, with implications for tests of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix.