Improved signal-to-noise ratio in EPI sequences with highly asymmetric spin echo and highly asymmetric STEAM preparations (HASE-EPI and HASTEAM-EPI)

Magnetic Resonance Materials in Physics, Biology and Medicine - Alternative versions of echo-planar imaging (EPI) sequences with standard spin echo (SE) or stimulated echo acquisition mode (STEAM)...     

Fiber scaffolds of polysialic acid via electrospinning for peripheral nerve regeneration

Fiber scaffolds of bioactive polysialic acid have been prepared via electrospinning for peripheral nerve regeneration. The diameter, morphology and alignment of fibers in scaffolds were adjusted by variation of electrospinning parameters, which are decisive for the cell-scaffold interaction. Due to the high water solubility of polysialic acid (poly-α-2,8-N-acetylneuraminic acid) a photoactive derivative (poly-α-2,8-N-pentenoylneuraminic acid) was used to obtain stable fiber scaffolds in water by photochemical crosslinking. At the optimized fiber scaffolds good cell viability and directed cell proliferation along the fibers was achieved by cell tests with immortalized Schwann cells.     

The letter of recommendation effect in informant ratings of personality.

In most studies using informant reports of personality, the informants are recruited by the targets. Such informants may tend to like the targets and thus portray them in specific ways (e.g., too positively). Study 1 (N = 403) demonstrated the necessity to distinguish between “liking” and “knowing” in studying the relationships between informants and targets. Informants who liked their targets better described them more positively (i.e., as being more extraverted, agreeable, open, conscientious, and less neurotic). The association between personality ratings and liking was moderated by item evaluativeness. Liked targets were also described as being more similar to each other (range restriction), which would lower correlations of informant ratings of personality with external variables. Study 2 (N = 90) used a within-subjects design to disentangle actual personality differences between targets (substance) from the informants’ specific views on the targets (style). Ninety informants were asked to nominate targets they did not like. These targets then nominated informants of their own choice. Target-nominated informants liked the targets very much and described the targets’ personalities very positively and in ways that were highly redundant with the average target’s self-rating. There was evidence that lower liking may be associated with better accuracy. Higher subjective levels of knowing were not associated with better interrater agreement but with a greater willingness to describe targets negatively. Implications for the field of recruiting are discussed. Where possible, the choice of informants and referees should be made independent of the targets’ preferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The significance of air velocity and turbulence intensity for responses to horizontal drafts in a constant air temperature of 23°C

Aim: The aim was to prove the significance of air velocity and turbulence intensity on the responses to drafts and if air velocity is adequately weighted in the draft rating model (DR-model) proposed in ISO 7730 (1994). Methods: Seventeen healthy persons (9 women, 8 men, 19–51 yr) took part in 12 randomly arranged 1-h sessions where horizontal drafts were directed towards the dorsolateral body sites of the sedentary persons. Mean air velocity was varied in 4 (  m/s) and turbulence intensity in 3 steps (Tu: <30,≈50,>70%) but were kept constant during the single sessions, whereas air velocities were increased every 15 min in the basic experiments performed for the DR-model. Air temperature was 23°C, humidity varied between 40% and 60%. Subjective perception and annoyance due to drafts were registered every 5 min using a list of prescribed body parts and skin temperature was measured continuously throughout the sessions at the forearm and at the neck. Results: Draft-induced general annoyance (if draft-induced annoyance was stated for at least one body site) and draft-induced local annoyance as stated for the neck and for the forearm increased with air velocity and/or with turbulence intensity. The decrease in skin temperature, however, was only related to air velocity but not to turbulence intensity. Air velocities are obviously not accurately weighted in the draft-rating model (ISO 7730, 1994). As compared to the effects observed here, the effects predicted with the DR-model were smaller in case of mean air velocities of 0.3 m/s and less but greater for 0.4 m/s. Concerning rather sedentary persons it seems that drafts are tolerable as long as mean air velocities do not exceed 0.2 m/s and as long as turbulence intensity remains below 30% in air temperature of 23°C.

Relevance to industry

Drafts are the most annoying climatic factor at many workplaces and assumed to reduce satisfaction with work, to impair performance and perhaps even health (Griefahn et al., Ind. Health 38 (2000b) 30). The limitation of drafts is therefore an important contribution to industrial safety. Using the draft-rating model proposed in ISO 7730 (1994) for the evaluation and for the prediction of draft-induced annoyance, it must be considered that the model underestimates the effects of drafts in case of air velocities of 0.3 m/s which prevail at more than 85% of workplaces in offices and in the industry (Griefahn, 1999; Zhou, Ph.D. Thesis, International Center for Indoor Environment and Energy, Department of Energy Engineering, Technical University of Denmark, Lyngby, 1999).     

Basic model for membrane electrode assembly design for direct methanol fuel cells

This research proposes a model that predicts the effect of the anode diffusion layer and membrane properties on the electrochemical performance and methanol crossover of a direct methanol fuel cell (DMFC) membrane electrode assembly (MEA). It is an easily extensible, lumped DMFC model. Parameters used in this design model are experimentally obtainable, and some of the parameters are indicative of material characteristics. The quantification of these material parameters builds up a material database. Model parameters for various membranes and diffusion layers are determined by using various techniques such as polarization, mass balance, electrochemical impedance spectroscopy (EIS), and interpretation of the response of the cell to step changes in current. Since the investigation techniques cover different response times of the DMFC, processes in the cell such as transport, reaction and charge processes can be investigated separately. Properties of single layers of the MEA are systematically varied, and subsequent analysis enables identification of the influence of the layer's properties on the electrochemical performance and methanol crossover. Finally, a case study indicates that the use of a membrane with lower methanol diffusivity and a thicker anode micro-porous layer (MPL) yields MEAs with lower methanol crossover but similar power density.     

3 siblings with identical, rare pneumopathy

Pulmonary alveolar microlithiasis was found in three siblings. Only the youngest of them, a former smoker, developed endstage lung disease. The other two are asymptomatic with normal lung function despite impressive changes on all chest radiographs. The role of smoking in perpetuating microlithiasis and furthering the progression of this disease is discussed.     

Thesen und Trends &#x0096; Mit funktionalen Oberflächen in die Zukunft

Propositions and Trends &#x0096; With Functional Surfaces into the Future Functional surfaces are the key to innovative products. Already today the properties, lifetime, and costs for most industrial and consumer products are determined by functionalised surfaces. Three Fraunhofer Institutes supported by the BMBF investigated the actual state of the art of production technology regarding functional surfaces, their future perspectives and the research and development demand. The results are published in the study “Production technology for the generation of functional surfaces” available at info@ist.‐ fraunhofer.de and the essentials are summarised in this article.     

Healthcare IT Standardization: Will the New Stimulus Package Help?

As IT professionals, we'll be watching President Barack Obama's efforts to launch a standardized national healthcare IT system in a way his predecessor couldn't, but as US citizens, we have a vested interest in all-inclusive medical care at a reduced cost.