Electrospun poly(aspartic acid) gel scaffolds for artificial extracellular matrix

Biocompatible synthetic polymer gel scaffolds for tissue engineering and regenerative medicine were prepared by reactive electrospinning. Protein‐like nano‐ and microfibres from chemically crosslinked polysuccinimide were obtained. Fibrous poly(aspartic acid) gels with size similar to that of extracellular matrix were obtained by hydrolysis of the polysuccinimide gel fibres. The effects of process parameters on fibre morphology (diameter, swelling degree) and chemical structure were investigated. Sub‐micrometre‐sized biocompatible fibrous scaffolds from a poly(amino acid) is a novel approach with great promise in several biomedical applications due to the tailor‐made synthetic nature, extreme purity and possibility of production on a large scale. © 2014 Society of Chemical Industry     

Predictors and correlates of taste preferences in European children: The IDEFICS study

The present study investigated taste preferences in a sample of 1705 children aged 6 to 9 years from survey centres in Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary, and Spain and aimed to identify factors correlated with taste preference. Children’s preferences for varying levels of sucrose (sweet) in apple juice and fat, sodium chloride (salt) and monosodium glutamate (umami) in crackers were assessed using paired-comparison tests. Socio-demographics (age, sex, parental education), early feeding practises (breastfeeding, introduction of fruits), parenting behaviour (TV viewing, using food as a reward) and taste threshold sensitivity for sucrose (sweet), sodium chloride (salt), caffeine (bitter) and monosodium glutamate (umami) were investigated as possible correlates of taste preferences. Parents reported on socio-demographics, early feeding and parenting behaviour. Taste thresholds were determined via a paired-comparison staircase method. Country of residence was the strongest factor related to preferences for all four tastes. Taste preferences also differed by age. Preference for sugar and salt increased between 6 and 9 years of age while preference for monosodium glutamate decreased. The age differences remained significant even after adjustment for sex, country of residence, parental education and early feeding habits. Sex, parental education, early feeding habits, TV viewing, using food as a reward and taste thresholds were not consistently related to taste preferences among the survey centres. In summary, the results highlight the importance of culture and age in taste preferences in children younger than 10 years of age.     

Driving behaviors in early stage dementia: A study using in-vehicle technology

According to the Alzheimer's Association (2011), (1) in 8 people age 65 and older, and about one-half of people age 85 and older, have Alzheimer's disease in the United States (US). There is evidence that drivers with Alzheimer's disease and related dementias are at an increased risk for unsafe driving. Recent advances in sensor, computer, and telecommunication technologies provide a method for automatically collecting detailed, objective information about the driving performance of drivers, including those with early stage dementia. The objective of this project was to use in-vehicle technology to describe a set of driving behaviors that may be common in individuals with early stage dementia (i.e., a diagnosis of memory loss) and compare these behaviors to a group of drivers without cognitive impairment. Seventeen drivers with a diagnosis of early stage dementia, who had completed a comprehensive driving assessment and were cleared to drive, participated in the study. Participants had their vehicles instrumented with a suite of sensors and a data acquisition system, and drove 1–2 months as they would under normal circumstances. Data from the in-vehicle instrumentation were reduced and analyzed, using a set of algorithms/heuristics developed by the research team. Data from the early stage dementia group were compared to similar data from an existing dataset of 26 older drivers without dementia. The early stage dementia group was found to have significantly restricted driving space relative to the comparison group. At the same time, the early stage dementia group (which had been previously cleared by an occupational therapist as safe to drive) drove as safely as the comparison group. Few safety-related behavioral errors were found for either group. Wayfinding problems were rare among both groups, but the early stage dementia group was significantly more likely to get lost.     

Untersuchungen zu Interaktionen zwischen Fetten und Calciumcarbonat bzw. Dicalciumphosphatzusatz bei Verabreichung lipidreicher Rationen an wachsende Schweine

The Interactions between Different Feed Fat Types and Respective Supplements of CaHPO₄·2H₂O and CaCO₃ on Some Nutritional- Physiological Parameters when Feeding Lipid Enriched Rations to Growing Pigs. In four, 3 × 4-factorial digestibility and balance experiments involving in all 48 growing pigs (46 to 60 kg live weight, 4 animals per group), the interactions between four feed fat types (refiend and hardened fish oil 35–37°C; refined coconut fat, poultry oil and soya oil) and three levels of feed calcium and phosphorus (I, II and III) on the apparent digestibility of crude fat, the apparent digestibility of fatty acids, the excretion of fecal soaps, the balances of the elements calcium, phosphorus, magnesium, sodium and potassium as well as the renal and fecal excretion of these minerals was investigated. Per trial 10% by weight of a fat type (fist oil, coconut fat, poultry oil and soya oil) was added to the otherwise identical growers diet. The sole intra-trial difference was the exclusion of a mineral supplement in diet I, the inclusion of 1% by weight of CaHPL₄·2H₂O in diet II and the inclusion of 1% by weight of CaCO₃ in diet III. The fat type constituted the inter-trial variable. Each of the rations fed in the digestibility/balance investigations was fed ot a finishing pig (100 to 110 kg live weight) in the slaughter experiments involving in all 12 hogs. After a 10 day feeding period the 3 pigs per trial were sacrificed, and digesta samples from 5 segments of the gastrointestinaltract (the abomasum, the proximal duodenum, the ileum, the caecum, and the distal rectum) was collected to study the effects of the factors feed-fat-types as well as calcium- and phosphorous levels on the formation of soaps in contents from the alimentary canal. The results of the two trial series were discussed.     

Mixing study of L shape mixheads in reaction injection molding

The effect of mixhead geometry on the impingement mixing in the reaction injection molding (RIM) process is largely unknown. In this study, high speed photographs are used to show the flow patterns produced by L shape mixheads. The mixing quality of the conventional I and various L shape mixheads is quantified by an emulsion test. The adiabatic temperature rise of a polyurethane/urea system is followed to further characterize the mixing produced by I and L shape mixheads. The results show that L shape mixheads give a better mixing quality than the I shape mixhead, especially at lower Reynolds numbers. In addition, the L shape mixheads can provide a more laminar flow from the mixhead, which is important for mold filling.     

Comparative interference by haemolysis in automated assays for bilirubin at multiple analyte concentrations

The negative interference caused by haemolysis in manual bilirubin assays contrasts with the positive interference reported for some automated methods utilizing the same basic chemistry. A comparison was therefore made of the haemolysis interference associated with several automated bilirubin methodologies: multilayer film (Kodak Ektachem- total bilirubin (TBil), direct bilirubin (DBil), conjugated bilirubin (Bc), unconjugated bilirubin (Bu),; tableted reagents (Baxter Paramax- TBil, DBil); continuous flow (Technicon SMAC — TBil). Thirty serum pools were analysed (five concentrations of bilirubin, 2-229 μmol/l; six concentrations of haemoglobin, 0.00002-0.052 mmol/1). All methods, except one (Bc), exhibited both positive and negative interference, depending upon the relative haemoglobin and bilirubin concentrations. This interference, at any given haemoglobin concentration, was neither constant nor proportional with increasing bilirubin concentration. These complex patterns of interference suggest that the best characterization of interference is obtained when (1) both percentage-difference and absolute-difference ‘interferographs’ are plotted; and (2) the interference is determined at multiple analyte concentrations.     

Small-Signal Dynamic Analysis of Regulated Class E DC/DC Converters

Class E dc/dc converters can operate at high switching frequencies with very low switching power losses. Using commercially available power transistors and diodes, Class E converters can operate at switching frequencies in the low-MHz range, with efficiencies of about 85 percent. Previous papers dealt with the circuit parameter values needed to obtain high-efficiency operation and output-voltage regulation, and with the static control characteristics of the Class E dc/dc converter cell. The analysis is extended to include the dynamic control characteristics and further information about the static characteristics. The theoretical predictions are verified by experimental measurements on a 40-W 1.5-MHz converter.     

Microstructural aspects of neutron embrittlement of reactor pressure vessel steels - A view from positron annihilation spectroscopy

A comprehensive review of positron annihilation studies of Cr---Mo---V reactor pressure vessel (RPV) steels (Soviet type 15Kh2MFA) in unirradiated and neutron irradiated states is presented. The influences of lattice defects, impurity atom distribution, irradiation temperature, flux and fluence of fast neutrons on positron annihilation parameters, especially during isochronal annealing, are discussed in terms of the positron trapping model. In contrast to the literature, where irradiation-enhanced Cu precipitates and solute coated microvoids are thought to be major defect types responsible for strengthening and hence embrittling of RPV steels, we suggest irradiation-induced precipitates, i.e. probably carbides, to play this role. Possibilities to probe this model are suggested.