Self-administered preventive programme for sedentary workers: reducing musculoskeletal symptoms or increasing awareness?

The objective of this study was to evaluate an auto-instructional preventive programme designed to allow the subjects to identify critical aspects related to their work and musculoskeletal comfort, and provide them with some simple alternatives for controlling the identified problems. The programme was evaluated by 36 secretaries and bank clerks through their symptom perception before and after the programme. The results showed that the symptoms increased in number and severity. The programme seemed to have helped the participants to become aware of the ergonomic problems present in their job and to link these problems to physical symptoms. Self-administered preventive programmes can lead to clearly negative results when applied as the only measure to control musculoskeletal symptoms.     

一种液体折射率的薄膜干涉测量方法

理论分析表明在镀有金属分光膜的玻璃介质和金属介质构成的几何楔形成的斐索干涉条纹中,相长干涉并不位于相邻的两相消干涉的中央,而是存在一明显偏移,这一偏移与引入几何楔中待测液体的折射率相关.基于该原理,提出了一种新的折射率测量的方法,并对该方进行了实验验证.该方法不需要利用标准液对光学几何量进行标定,测量范围广.     

Retrograde Amnesia in Dementia: Comparison of HIV-Associated Dementia, Alzheimer's Disease, and Huntington's Disease.

Remote memory was assessed in persons with HIV-associated dementia (HIV-D), probable Alzheimer's disease (AD), and Huntington's disease (HD) and in healthy controls. The clinical groups were similar in overall dementia severity. Each clinical group exhibited impairments on remote memory tests relative to controls; however, temporally graded memory loss with selective preservation of older information was observed in the AD group but not the HD or HIV-D group. Analysis of cued retrieval indicated a preferential cuing benefit for the HIV-D and HD groups relative to the AD group. The similar pattern of remote memory performance demonstrated by the HIV-D and HD groups is a novel finding and suggests a subcortically mediated retrograde amnesia in HIV-D. The temporally graded pattern and the abnormal cued retrieval performance in the AD group are consistent with a consolidation deficit associated with extrahippocampal (cortical) and hippocampal damage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Steam reforming of methanol over ruthenium impregnated ceria,alumina and ceria–alumina catalysts

The wet impregnation method was used to prepare different ruthenium promoted Ce–Al catalysts. These catalysts were used in the steam reforming of methanol reaction (SRM). The effects of the reaction temperature (200–400 C) and the catalyst composition were studied for optimization reasons. The steam to methanol molar ratio was kept constant (S/M = 2). The promotion of cerium/aluminum oxides with Ru enhanced their catalytic activity. The catalytic test results showed that the Ru/Ce combination was the most beneficial. The synergy between Ru and cerium oxide led to the formation of active sites with excellent redox properties. For high active phase content, the 5 RuCe catalyst exhibited the highest hydrogen production amount with no CO formation. This catalyst was kept under stream for 5 days at 400 C, and no significant deactivation was observed. Copyright © 2016 John Wiley & Sons, Ltd.     

Expectation versus variation: Students’ decision making in a sampling environment

Abstract:

A task adapted from one used by Tversky and Kahneman (1971) was used in an interview or questionnaire context with 122 students from Grade 3 to Grade 13. Two questions assessed student understanding of the relationship of a sample to a population and of the expected value of the arithmetic mean, with and without information on a single value from the sample. Combining responses to the two questions, increasingly complex hierarchical sequences were identified in the observed responses in relation to the expected value of the means, an expectation variable, and in relation to the degree that ideas about variation were used to support judgements, a variation variable. Using data from another task performed by 68 of the students, responses were associated with the observed development of understanding of sampling more generally, a basic sampling variable. Overall, the associations of levels of response among the variables was not strong, suggesting more explicit discussion of sampling issues is required in classrooms.     

Autothermal hybridization and controlled production of hydrogen-rich syngas in a molten salt solar gasifier

High efficiency solar steam gasification of biomass is carried out in a prototype molten salt reactor for solar-only and solar-autothermal hybrid operation. Previous demonstration of the prototype 3-kW solar gasifier for steam gasification of cellulose at stoichiometric conditions demonstrated thermal efficiency of 44% during continuous operation at 1200 K. The present work expands the range of operating conditions to consider two challenges. Hybridization between solar and autothermal modes of operation is accomplished by adding oxygen directly to the reactor. Control of the H₂:CO ratio of the product gas is accomplished through in-situ steam shifting. Hybridization stabilized temperatures for variations in radiative input as large as a 30% reduction in power, corresponding to conditions where both sensible and chemical heat demands for the process were fully met by exothermic heat release with no significant challenges. Peak efficiencies and carbon conversion values observed are 45% and 99.5% respectively. The resulting product gas stream composition was shifted from a hydrogen and carbon monoxide ratio of 1:1 with stoichiometric steam delivery to a ratio of 1.7:1 with steam at nine times the stoichiometric amount, only slightly lower than equilibrium predictions. The results demonstrate very favorable attributes for the molten salt reactor in a continuous fuel production process.     

Isomeric Carborane Neuromuscular Blocking Agents

We synthesized a family of neuromuscular blocking agents (NMB) based on decamethonium, but containing a carborane cluster in the methylene chain between the two quaternary ammonium groups. The carborane cluster isomers o-NMB, m-NMB, and p-NMB were tested in animals for neuromuscular block and compared with agents used clinically: rocuronium and decamethonium. All three isomers caused reversible muscle weakness in mice as determined by grip strength and inverted screen tests, with a potency rank of p-NMB > rocuronium > decamethonium > m-NMB > o-NMB. The mechanism of action of the compounds was determined by using the in vitro rat phrenic nerve hemi-diaphragm preparation and electrophysiologic measurements in cells. Neostigmine reversed hemi-diaphragm weakness caused by the three isomers and rocuronium, but not succinylcholine. In electrophysiologic recordings of currents through acetylcholine receptor channels, the carborane compounds did not activate channel activity but did inhibit channel activation by acetylcholine. These results demonstrate that the carborane neuromuscular blocking agents are non-depolarizers in contrast to the depolarizing action of the parent compound.     

Amelioration in physicochemical properties and single cell performance of sulfonated poly(ether ether ketone) block copolymer composite membrane using sulfonated carbon nanotubes for intermediate humidity fuel cells

A composite membrane composed of a sulfonated diblock copolymer (SDBC) based on poly(ether ether ketone) blocks copolymerized with partially fluorinated poly(arylene ether sulfone) and sulfonated carbon nanotubes (SCNTs) was fabricated by simple solution casting. Addition of the SCNT filler enhanced the water absorption and proton conductivity of membranes because of the increased per‐cluster volume of sulfonic acid groups, at the same time reinforced the membranes' thermal and mechanical properties. The SDBC/SCNT‐1.5 membrane exhibited the most improved physicochemical properties among all materials. It obtained a proton conductivity of 10.1 mS/cm at 120°C under 20% relative humidity (RH) which was 2.6 times more improved than the pristine membrane (3.9 mS/cm). Moreover, the single cell performance of the SDBC/SCNT‐1.5 membrane at 60°C and 60% RH at ambient pressure exhibited a peak power density of 171 mW/cm² at a load current density of 378 mA/cm², while the pristine membrane exhibited 119 mW/cm² at a load current density of 294 mA/cm². Overall, the composite membrane exhibited very promising characteristics to be used as polymer electrolyte membrane in fuel cells operated at intermediate RH.