Polymerization of calcium caseinates solutions induced by gamma irradiation

Solutions of calcium caseinate (5%) combined with propylene glycol (PG) or triethylene glycol(TEG) (0, 2.5% and 5%) and used for the development of edible films and coatings, were irradiated at doses between 0 to 128 kGy. Solutions were chromatographed through toyopearl HW 55F resin to observe the effect of irradiation on cross-link reactions. In unirradiated calcium caseinate solutions, two peaks could be observed (fractions 30 and 37) while samples irradiated at 64 kGy and 128 kGy showed one shifted peak at fraction 32 and 29 respectively. No effect of the plasticizers was observed. According to proteins standards of knowed molecular weights, the molecular weight of calcium caseinate increased approximately 10 times when irradiated at 128 kGy and 5 times when irradiated at 64 kGy. The physico-chemical properties of bio-films prepared with the irradiated solutions, demonstrated that tensile strength at break increased with increase of irradiation dose. A maximum dose was obtained at 16 kGy.     

Seated occupant interactions with seat backrest and pan, and biodynamic responses under vertical vibration

The relative interactions of the seated occupants with an inclined backrest were investigated in terms of apparent mass (APMS) responses at the two driving-points formed by the buttock-seat pan and the upper body-backrest under exposure to broad-band and road-measured vertical vibration. The measurements were performed using 24 adult subjects seated with full contact with the back support and two different positions of the hands (in lap and on steering wheel), while exposed to three different levels of broad band (0.25, 0.5 and 1.0 m/s² rms acceleration) vibration in the 0.5-40 Hz frequency range, and a track-measured vibration spectrum (1.07 m/s² rms acceleration). The forces developed on the seat pan and the backrest in directions normal to the supporting surfaces were measured to derive the APMS responses at both the driving-points. The results showed significant interactions of the upper body with the back support in a direction normal to the backrest, even though the vibration is applied along the vertical axis. At low frequencies, the backrest APMS magnitude was smaller than that measured at the seat pan, but it either exceeded or approached that of the seat pan APMS in the vicinity of the primary resonant frequencies. The results also suggested considerable effect of the hands position on the APMS magnitudes measured at both the driving-points. The effects of variations in the excitation type and magnitude, considered in this study, were observed to be small compared to those caused by the hands position and individual body masses. Owing to the strong effects of the body mass on the measured APMS responses at both driving-points, a total of 8 target data sets were identified corresponding to four mass groups (<60, 60.6-70, 70.5-80 and >80 kg) and two hands positions for formulating mechanical equivalent models. The model parameters identified for the target functions suggested that the models mass, stiffness and damping parameters increase with increasing body mass. The observed variations in the identified parameters could be applied for predicting the APMS responses reflected on the pan as well as backrest of the human occupants with specific body mass.     

Novel (4 + 1) fragment combination approach to chiral cyclopentanoids from tartaric acid

A $\text{chiral}$ cyclopentanoid building block $\text{29}$ has been synthesized in “one pot” cyclization process from epoxides $\text{22}$ - $\text{25}$ (which are readily accessible from (R,R)-(+) tartaric acid) with the carbanion derived from phenylthioacetonitrile (PhS-CH₂-CN).     

Synthese totale et stereoselective du dimethyl-6,10 methylidene-9 undecene-5 (e) one-2: un des constituants de l'huile de Costus

The first total and stereoselective synthesis of (E)-6, 10 dimethyl-9 methylidene undec-5-en-2-one: a constituant of Costus Root oil is reported. It was conducted with an overall yield of 22% from 1-methyl-2-oxo-methylcyclopentane carboxylate (α-methylated Dieckmann-ester) $\text{2}$, used as a starting material.     

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.     

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.