Vibrational dephasing effects and motional narrowing in the isotropic Raman Q branch of HD

Important motional narrowing has been previously experimentally observed by Dion and May in the isotropic Raman Q branch of pure gaseous HD in the fundamental vibrational band. A recent theoretical calculation of the present authors, in good agreement with these experiments, has shown that for pure HD only rotational mechanisms are efficient. In this paper, an infinite order treatment of the vibrational dephasing effects for HD perturbed by rare gases indicates an important role of these last effects in the broadening of the individual lines (particularly in the 0–2 band) leading to a significant decrease of the motional narrowing in the resulting band profile at high density.     

Carbon-13 NMR studies of nitrogen compounds. I—substituent effects of amino,acetamido, diacetamido,ammonium and trimethylammonium groups

¹³C NMR chemical shifts are reported for several alkyl or aryl amines, acetamides, diacetamides and ammonium and trimethylammonium salts. Substituent effects, determined with respect to chemical shifts of amino derivatives, are rationalized in terms of γ effects, steric interactions and for benzene derivatives, in terms of competition between inductive (σ₁) and resonance (σ_R) effects. These perturbations can be used to assign chemical shifts of complex structures and to study certain chemical processes.     

Multi-gram synthesis of a porphyrazine platform for cellular translocation, conjugation to Doxorubicin, and cellular uptake

We report the synthesis of the near infrared (NIR) fluorescent porphyrazine (Pz) 285, with pendant hydroxyl groups, as a non-toxic platform for delivery of conjugated chemotherapeutic agents to tumor cells. Conjugation of Pz 285 to Doxorubicin via an acid labile linker and initial biological studies are reported.     

A new method for the determination of the relative affinity of a ligand against various DNA sequences by electrospray ionization mass spectrometry. Application to a polyamide minor groove binder

A new method for the determination of the relative affinity of a ligand against various dsDNA sequences is presented by using electrospray ionization time‐of‐flight mass spectrometry (ESI‐QTOF) mass spectrometry. The principle is described here through the complexation of double‐stranded DNA by a polyamide ligand including twelve N‐methylpyrrole rings. However this method could be applied to other ligands especially when dissociation constants (K_d) are in nanomolar range. This method does not require knowing the ligand concentration accurately. It allows determination of the relative affinity of a ligand against various dsDNA sequences for 1 : 1 complex stoichiometries in a quick manner without labeling. Copyright © 2009 John Wiley & Sons, Ltd.     

Light particle coincidences with gross structure in energy spectra from the40Ca+40Ca collision

Proton and pion spectra from relativistic heavy ion collisions are calculated in the framework of a hydrochemical model. An explanation of the striking absence of the delta decay pion peak in the observed pion spectra is suggested.     

Etude en Résonance Magnétique Nucléaire du Carbone-13 de N-Aryl Pyrazolines-2 Diversement Substituées. Effets de Substituant et Etude Conformationnelle

The ¹³C chemical shifts of 1-phenyl-2-pyrazoline and 25 N-nitrophenyl-2-pyrazolines, with different substituents on the heterocyclic ring, have been assigned. These values are discussed as a function of the steric and electronic nature of the various substituents. The steric effects produced conformational modifications, both in the nitrophenyl and 2-pyrazoline moieties, which explain some of the chemical shifts.     

Isolation and structural characterization of the first thermally robust and air stable Cr(4+) bent-metallocene complex

The first thermally robust and air stable bent-sandwich chromocene complex with chromium in the +4 oxidation state has been isolated and fully characterized.     

Inclusive double-pomeron exchange at the fermilab tevatron p p collider

We report results from a study of events with a double-Pomeron exchange topology produced in p p collisions at sqrt[s]=1800 GeV. The events are characterized by a leading antiproton and a large rapidity gap on the outgoing proton side. We find that the differential production cross section agrees in shape with predictions based on Regge theory and factorization, and that the ratio of double-Pomeron exchange to single diffractive production rates is relatively unsuppressed as compared to the O(10) suppression factor previously measured in single diffractive production.     

Search for B0s-->micro+micro- and B0d-->micro+micro- decays in pp collisions at square root s = 1.96 TeV

We report on a search for B(0)(s)-->micro(+)micro(-) and B(0)(d)-->micro(+)micro(-) decays in pp collisions at square root of s=1.96 TeV using 171 pb(-1) of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The decay rates of these rare processes are sensitive to contributions from physics beyond the standard model. One event survives all our selection requirements, consistent with the background expectation. We derive branching ratio limits of B(B(0)(s)-->micro(+)micro(-))<5.8x10(-7) and B(B(0)(d)-->micro(+)micro(-))<1.5x10(-7) at 90% confidence level.