Chiral Phosphoric Acid‐Catalyzed Enantioselective Aza‐Friedel–Crafts Alkylation of Indoles with γ‐Hydroxy‐γ‐lactams

An enantioselective aza‐Friedel–Crafts reaction of indoles with γ‐hydroxy‐γ‐lactams using a chiral phosphoric acid catalyst is reported. The approach described herein provides an efficient access to 5‐indolylpyrrolidinones in good to quantitative yields and excellent enantioselectivities (up to >99% ee). The results suggest that the reaction may proceed via N‐acyliminium intermediates associated with the chiral phosphoric acid anion.     

Effect of personality and status experience upon the valuation of unobtained statuses.

"An experiment was designed to test the effects of attained and unattained outcomes on the perception of subjective status by members of small groups… . Six groups… experienced all the outcomes… and the subjects in the remaining groups experienced the outcomes in only one of the… middle status positions… . Three variables were investigated: the presence of unattained outcomes for subjects in the status system, perception by the subjects of the possibility of status mobility, and a personality measure… . It was found that the personality variable was instrumental in the differential perception by subjects of attained and unattained outcomes." From Psyc Abstracts 36:04:4GE47G. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exemplar effects in the context of a categorization rule: Featural and holistic influences.

Brooks and colleagues (S. W. Allen & L. R. Brooks, 1991; G. Regehr & L. R. Brooks, 1993) have shown that the classification of transfer stimuli is influenced by their similarity to training stimuli, even when a perfect classification rule is available. It is argued that the original effect obtained by Brooks and colleagues might have resulted from two potential confounding variables. Once these confounds were controlled, the current authors did not replicate Brooks and colleagues' results in Experiment 1. Exemplar effects appeared in Experiment 2 when transfer stimuli were perceptually more similar to training stimuli than in Experiment 1. In Experiment 3, the authors obtained exemplar effects with separated stimuli, a finding that was not predicted by Brooks and colleagues' model. The authors suggest that a close perceptual match between training and transfer stimuli is necessary for the effect to occur, for both integrated and separated stimuli. The nature of this perceptual match, holistic or featural, is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced Electrocaloric Response of Vinylidene Fluoride–Based Polymers via One-Step Molecular Engineering

Electrocaloric refrigeration is one of the most promising environmentally-friendly technologies to replace current cooling platforms—if a notable electrocaloric effect (ECE) is realized around room temperature where the highest need is. Here, a straight-forward, one-pot chemical modification of P(VDF-ter-TrFE-ter-CTFE) is reported through the controlled introduction of small fractions of double bonds within the backbone that, very uniquely, decreases the lamellar crystalline thickness while, simultaneously, enlarging the crystalline coherence along the a-b plane. This increases the polarizability and polarization without affecting the degree of crystallinity or amending the crystal unit cell—undesirable effects observed with other approaches. Specifically, the permittivity increases by >35%, from 52 to 71 at 1 kHz, and ECE improves by >60% at moderate electric fields. At 40 °C, an adiabatic temperature change >2 K is realized at 60 MV m⁻¹ (>5.5 K at 192 MV m⁻¹), compared to ≈1.3 K for pristine P(VDF-ter-TrFE-ter-CTFE), highlighting the promise of a simple, versatile approach that allows direct film deposition without requiring any post-treatment such as mechanical stretching or high-temperature annealing for achieving the desired performance.     

Modelling of multiple impacts for the prediction of distortions and residual stresses induced by ultrasonic shot peening (USP)

During a manufacturing process, the ultrasonic shot peening (USP) technique can be used as the final surface treatment. The aim of this operation is to introduce surface compressive residual stresses in order to prevent crack propagation advancement. Although the numerical simulation method is able to predict the level of residual stresses in a peened part, the 3D modelling of the real USP process, in which many successive and shifted impacts take place, is very delicate to perform and costly in terms of computing time and memory space required. In this paper, a two step method based at first on the calculation of the averaged plastic strain tensor in a half-space by using a semi-analytical method and in a second time on the transfer of this plastic strain field to a finite element model is proposed in order to simulate the effects of the USP process in thin structures. The accuracy and advantages of the semi-analytical method are validated by a benchmark with several finite element codes. Experiments, similar to the Almen test, are performed on thin plates of Inconel 600. Numerical results in terms of distortions and residual stresses are compared with the experimental data.     

The interference of pharmaceuticals with endogenous and xenobiotic metabolizing enzymes in carp liver: an in-vitro study

The interactions of fibrate (clofibrate, fenofibrate, bezafibrate, gemfibrozil), antiinflammatory (ibuprofen, diclofenac, naproxen, ketoprofen), and anti-depressive (fluoxetine,fluvoxamine, paroxetine) drugs with CYP catalyzed pathways (CYP1A, CYP3A-, CYP2K-, and CYP2M-like) and Phase II activities (UDP-glucuronosyltransferases and sulfotransferases), involved in both xenobiotic and endogenous metabolism in fish, were investigated in-vitro by incubating carp liver subcellular fractions in the presence of the substrate and the selected drug. Anti-depressive drugs were strong inhibitors of CYP1A (92-94% inhibition), CYP3A-like (69-80% inhibition), and CYP2K-like (36-69% inhibition) catalyzed activities, while antiinflammatory drugs were potent CYP2M-like inhibitors (32-74% inhibition). Among the lipid regulators, gemfibrozil strongly inhibited CYP2M-catalyzed activity (91% inhibition) and other CYP isoforms (CYP1A and CYP3A-like). Additionally, glucuronidation of naphthol and testosterone were targeted by antiinflammatory drugs, and to a lesser extent, by fibrate drugs (48-78% inhibition). No significant alteration on sulfotransferase activities was observed, apart from a minor inhibitory effect of clofibrate, gemfibrozil, and fluoxetine on the sulfation of estradiol. Overall, gemfibrozil, diclofenac, and the three anti-depressive drugs appear to be the pharmaceuticals with the highest potential to interfere with fish metabolic systems.     

High-Curie-temperature ferromagnetism in self-organized Ge1-xMnx nanocolumns

The emerging field of spintronics would be dramatically boosted if room-temperature ferromagnetism could be added to semiconductor nanostructures that are compatible with silicon technology. Here, we report a high-TC (>400K) ferromagnetic phase of (Ge,Mn) epitaxial layer. The manganese content is 6%, and careful structural and chemical analyses show that the Mn distribution is strongly inhomogeneous: we observe eutectoid growth of well-defined Mn-rich nanocolumns surrounded by a Mn-poor matrix. The average diameter of these nanocolumns is 3nm and their spacing is 10nm. Their composition is close to Ge(2)Mn, which corresponds to an unknown germanium-rich phase, and they have a uniaxially elongated diamond structure. Their Curie temperature is higher than 400K. Magnetotransport reveals a pronounced anomalous Hall effect up to room temperature. A giant positive magnetoresistance is measured from 7,000% at 30K to 200% at 300K and 9T, with no evidence of saturation.     

Interconversion of linearly viscoelastic material functions expressed as Prony series: a closure

Interconversion of viscoelastic material functions is a longstanding problem that has received attention since the 1950s. There is currently no accepted methodology for interconverting viscoelastic material functions due to the lack of stability and accuracy of the existing methods. This paper presents a new exact, analytical interconversion method for linearly viscoelastic material functions expressed as Prony series. The new algorithm relies on the equations of the thermodynamics of irreversible processes used for defining linearly viscoelastic constitutive theories. As a result, interconversion is made possible for unidimensional and tridimensional materials for arbitrary material symmetry. The algorithm has been tested over a broad range of cases and was found to deliver accurate interconversion in all cases. Based on its accuracy and stability, the authors believe that their algorithm provides a closure to the interconversion of linearly viscoelastic constitutive theories expressed with Prony series.