An single program multiple data strategy for calculation of anharmonic vibrations

This paper presents a general perturbational and variational scheme to calculate solutions of the spectral problem for the vibrational molecular Hamiltonian. A parallel strategy in the ongoing development of our software P_Anhar is presented, in order to calculate the vibrational spectrum of medium sized molecules. The efficiency of this approach is checked on ethylene oxide.     

Hydrolysis-condensation reactions of titanium alkoxides in thin films: A study of the steric hindrance effect by X-ray photoelectron spectroscopy

An original approach based on X-ray photoelectron spectroscopy (XPS) is proposed to study the influence of the surrounding humidity on the hydrolysis-condensation reactions of five titanium alkoxides in thin films. More precisely, the influence of the nature of the ligands (propoxide, butoxide, isopropoxide, phenoxide, and 9H-carbazole-9-yl-ethyl-oxy) on the reaction rate was evidenced. The reaction advancement was evaluated by comparing XPS chemical compositions to theoretical compositions calculated for all the possible rates. XPS chemical environment information allowed validating the reliability of this approach through the evaluation of the condensation state. In both approaches, the influence of the steric hindrance on the reactivity of titanium alkoxides was highlighted to be similar to what has been previously observed in solution. Theses results corroborate the validity of our XPS approach to determine titanium alkoxide hydrolysis-condensation reactions in the specific application of thin films.     

Comparison of the safety profiles of PLA50 and Me.PEG-PLA50 nanoparticles after single dose intravenous administration to rat

We compared the safety profiles of two types of nanoparticles intravenously administered to rats, prepared from PLA₅₀ and Me.PEG-PLA₅₀ by emulsification/solvent evaporation using cholate as tensioactive agent. With PLA₅₀/Cholate nanoparticles, no signs of toxicity were noted at 75 mg kg⁻¹. At higher doses, 220 and 440 mg kg⁻¹, marked toxicity (mortality and marked clinical signs) was observed with dose-related hematological changes (decrease of thrombocytes count, increase of Prothrombine Time and Activated Partial Thromboplastin Time) and biochemical changes (increase of aminotransferases activities). All changes were transient and disappeared on Day 9. With Me.PEG-PLA₅₀/Cholate nanoparticles, no lethality and no clinical changes were observed after intravenous administration of Me.PEG-PLA₅₀/Cholate even at high dose, up to 440 mg kg⁻¹. The improved safety profile of Me.PEG-PLA₅₀/Cholate nanoparticles as compared to PLA₅₀/Cholate nanoparticles suggests that the steric repulsion owing to the high density of Me.PEG chains on the nanoparticles surface prevents the coagulation cascade and associated toxicity.     

Shape Selectivity in Enol Thioether Synthesis Catalyzed by Zeolites

The competitive reaction catalyzed by solid acid catalyst between two cyclohexanones (1a) and (1b) with thiophenol (2) has been studied. No selectivity was observed with the lamellar montmorillonite in contrast with microporous aluminosilicates (zeolites) where shape selectivity was observed, in particularly when the zeolites were saturated by thiophenol (2) before a competitive reaction.     

Energetics of the biosynthesis of cyclopentenones from unsaturated fatty acids

Polyunsaturated fatty acids like linolenic acid or arachidonic acid upon enzymatic hydroxylation (lipoxygenases) can lead to corresponding hydroperoxides. Their dehydration gave rise to vinyl allene oxides, which cyclized into cyclopentenones, precursors of jasmonic acid or prostanoids.     

Synthesis of the 7‐Azaindole (1H‐Pyrrolo[2,3‐b]pyridine) Analogous to Cannabimimetic JHW 200

Cannabinoid agonists have been suggested to have potential therapeutic uses. The synthesis of a new cannabimimetic analogue of JHW 200 possessing a 7‐azaindole unit instead of an indole moiety is described. The approach used for indole derivatives failed, and a new strategy that involves the reaction of a nitrile and 1‐naphtyl magnesium bromide was studied.     

Organ Repair,Hemostasis, and In Vivo Bonding of Medical Devices by Aqueous Solutions of Nanoparticles

Sutures are traumatic to soft connective tissues, such as liver or lungs. Polymer tissue adhesives require complex in vivo control of polymerization or cross‐linking reactions and currently suffer from being toxic, weak, or inefficient within the wet conditions of the body. Herein, we demonstrate using Stöber silica or iron oxide nanoparticles that nanobridging, that is, adhesion by aqueous nanoparticle solutions, can be used in vivo in rats to achieve rapid and strong closure and healing of deep wounds in skin and liver. Nanoparticles were also used to fix polymer membranes to tissues even in the presence of blood flow, such as occurring after liver resection, yielding permanent hemostasis within a minute. Furthermore, medical devices and tissue engineering constructs were fixed to organs such as a beating heart. The simplicity, rapidity, and robustness of nanobridging bode well for clinical applications, surgery, and regenerative medicine.