Delayed onset of Alzheimer's disease with nonsteroidal anti-inflammatory and histamine H2 blocking drugs

Factors that modify onset of Alzheimer's disease (AD) may be revealed by comparing environmental exposures in affected and unaffected members of discordant twin pairs or sibships. Among siblings at high risk of AD, sustained use of nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with delayed onset and reduced risk of AD. After adjustment for use of NSAIDs, there was minimal effect on onset with reported history of any of three common illnesses (arthritis, diabetes, or acid-peptic disease). However, independent of exposure to NSAIDs, onset was unexpectedly delayed in those reporting extended use of histamine H2 blocking drugs. Randomized clinical trials will be needed to affirm the utility of these drugs for prevention, but the present findings may have implications for pathogenesis: because NSAIDs block the calcium-dependent postsynaptic cascade that induces excitotoxic cell death in NMDA-reactive neurons, and because histamine potentiates such events, excitotoxicity may deserve additional investigation in AD.     

Growth of a single-wall carbon nanotube film and its patterning as an n-type field effect transistor device using an integrated circuit compatible process

This study presents the synthesis of a dense single-wall carbon nanotube (SWNT) network on a silicon substrate using alcohol as the source gas. The nanosize catalysts required are made by the reduction of metal compounds in ethanol. The key point in spreading the nanoparticles on the substrate, so that the SWNT network can be grown over the entire wafer, is making the substrate surface hydrophilic. This SWNT network is so dense that it can be treated like a thin film. Methods of patterning this SWNT film with integrated circuit compatible processes are presented and discussed for the first time in the literature. Finally, fabrication and characteristic measurements of a field effect transistor (FET) using this SWNT film are also demonstrated. This FET is shown to have better electronic properties than any other kind of thin film transistor. This thin film with good electronic properties can be readily applied in the processing of many other SWNT electronic devices.     

An effectiveness trial of a dissonance-based eating disorder prevention program for high-risk adolescent girls.

Efficacy trials indicate that an eating disorder prevention program involving dissonance-inducing activities that decrease thin-ideal internalization reduces risk for current and future eating pathology, yet it is unclear whether this program produces effects under real-world conditions. The present effectiveness trial tested whether this program produced effects when school staff recruit participants and deliver the intervention. Adolescent girls with body image concerns (N = 306; M age = 15.7, SD = 1.1) randomized to the dissonance intervention showed significantly greater decreases in thin-ideal internalization, body dissatisfaction, dieting attempts, and eating disorder symptoms from pretest to posttest than did those assigned to a psychoeducational brochure control condition, with the effects for body dissatisfaction, dieting, and eating disorder symptoms persisting through 1-year follow-up. Effects were slightly smaller than those observed in a prior efficacy trial, suggesting that this program is effective under real-world conditions, but that facilitator selection, training, and supervision could be improved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analytical characterization of palatinit (author's transl)]

The reaction product of the catalytic hydrogenation of isomaltulose (palatinose) is a mixture of alpha-D-glucopyranosido-1,6-sorbitol and alpha-D-glucopyranosido-1,6-mannitol designated palatinit. Because of its high potential as a sugar substitute methods for the identification and characterization of hydrogenation products and for the determination of palatinit as an ingredient in food preparations and biological samples are required. Several working procedures are described in full detail including thin layer and gas chromatography as well as enzymatic and chemical determinations.     

A New Aspect of Magnesium Bromide‐Promoted Enantioselective Aryl Additions of Triaryl(tetrahydrofuran)aluminum to Ketones Catalyzed by a Titanium(IV) Catalyst of trans‐1,2‐Bis(hydroxycamphorsulfonylamino)cyclohexane

A novel aspect of MgBr₂‐promoted asymmetric triarylaluminum‐tetrahydrofuran [AlAr₃(THF)] additions to ketones catalyzed by a titanium catalyst of 20 mol% trans‐1,2‐bis(hydroxycamphorsulfonylamino)cyclohexane ( 2 ) is reported. The catalytic system works excellently for aromatic ketones with either an electron‐withdrawing or an electron‐donating substituent on the aromatic ring at the 2′‐, 3′‐, or 4′‐positions, affording tertiary alcohols in excellent enantioselectivities of ≥90% ee, except for the cases of phenyl addition to 2′‐methoxyacetophenone and 4‐trimethylsilylphenyl (4‐TMSC₆H₄) addition to acetopheneone.     

Global exponential stability for uncertain bidirectional associative memory neural networks with multiple time‐varying delays via LMI approach

The global exponential stability for uncertain delayed bidirectional associative memory neural networks (DBAMNN) with multiple time‐varying delays is considered in this paper. Delay‐dependent criteria are proposed to guarantee the robust stability of DBAMNN via linear matrix inequality approach. Two classes of system uncertainties are investigated in this paper. Some numerical examples are given to illustrate the effectiveness of our results. From the numerical simulations, significant improvement over the recent results can be observed. Copyright © 2007 John Wiley & Sons, Ltd.     

Flow and impingement cooling heat transfer along triangular rib-roughened walls

Experiments are performed to study slot air jet impingement cooling flow and the heat transfer along triangular rib-roughened walls. Both flow visualization and local heat transfer measurements along the ribbed wall are made. The effect of different rib protrusions (heights) on the impinging flow and heat transfer along the wall is studied, which is achieved by using different sizes of nozzles. Two different ribbed walls with different rib pitches are selected which have a rib pitch-to-height ratio of 2 and 4, respectively. The widely opened cavity between neighboring ribs make more intense transport of momentum between the wall jet and cavity flow so that recirculation cell in the cavity is hardly observed. This leads to a higher heat transfer around the cavity wall than in the case with rectangular ribs. However, in the region of laminar wall jet, a number of air bubbles enclosing the cavities are formed which prevent penetration of the wall jet into the cavities. This leads to a significant reduction in the heat transfer. The geometric shape of the triangular ribs is more effective in rebounding the wall jet away from the wall than in the case with rectangular ribs. The rebound of the jet away from the wall causes a significant reduction in the heat transfer. A comparison and correlations of the stagnating point Nusselt number under different conditions are presented and discussed. During the experiments, the Reynolds number varies from 2500 to 11,000, the slot width-to-rib height ratio from 1.17 to 6.67, and nozzle-to-plate spacing from 2 to 16.     

没有最好 只有更专业

在航空航天制造发展的过程中,材料的更新换代也呈现出高速的更迭变换,在未来航空航天制造中,一架飞机中复合材料、钛合金、镍合金和高温合金的含量将占主导地位,特别是复合材料的高速发展,有取代铝合金成为飞机制造应用中第一材料的趋势。虽然现在铝合金的比重还比较高,但是在军用直升机制造中已经采用了更多的复合材料,     

Reactive distillation of pyridine mixtures with an organic acid. I. Determination of the reactive distillation equilibrium

The reactive distillation equilibrium has been experimentally determined by chromatographic analysis of the vapor phase for various mixtures of two pyridines plus an organic acid in stoichiometric deficiency in an organic solvent. Protonation of pyridines by a weak acid seems to involve ion pair formation, while protonation by a strong acid seems to result in free ion formation, and may involve a small quantity of triple molecule ions (two pyridine molecules for one acid molecule). Steric effects are not significant in such ion formation and the chemical equilibrium constant can be predicted from the pyridine pK_a difference using a linear relationship. Despite the possible formation of triple molecule ions, the reactive distillation equilibrium at constant acid quantity can be reasonably well described as an ideal liquid-vapor equilibrium combined with an ideal chemical equilibrium. However, the increase of the chemical equilibrium constant with the acid quantity should be taken into account in a more refined model.     

Reactive distillation of pyridine mixtures with an organic acid. II. Parametric sensitivity and optimization of the process

A process of separation of close-boiling mixture by reactive distillation, exemplified by 3-/4-picoline separation through complexation with trifluoroacetic acid, has been analyzed in detail by numerical simulation. In such a process, the separation selectivity is supplied by a reversible chemical reaction and a displacement agent is used to regenerate the isomers. Parameter sensitivity analysis has shown the fundamental role played by the displacement agent in the regeneration as well as in the separation when the two isomers have to be recovered with the same purity. Optimization has shown that the displacement agent should ideally have an affinity for the reactive agent intermediate between that of the isomers to be separated. This affinity is measured by the ratio of the relative volatility to the chemical selectivity.