Carnitine-dependent metabolic activities in Saccharomyces cerevisiae: three carnitine acetyltransferases are essential in a carnitine-dependent strain

L-carnitine is required for the transfer of activated acyl-groups across intracellular membranes in eukaryotic organisms. In Saccharomyces cerevisiae, peroxisomal membranes are impermeable to acetyl-CoA, which is produced in the peroxisome when cells are grown on fatty acids as carbon source. In a reversible reaction catalysed by carnitine acetyltransferases (CATs), activated acetyl groups are transferred to carnitine to form acetylcarnitine which can be shuttled across membranes. Here we describe a mutant selection strategy that specifically selects for mutants affected in carnitine-dependent metabolic activities. Complementation of three of these mutants resulted in the cloning of three CAT encoding genes: CAT2, coding for the carnitine acetyltransferase associated with the peroxisomes and the mitochondria; YAT1, coding for the carnitine acetyltransferase, which is presumably associated with the outer mitochondrial membrane, and YER024w (YAT2), which encodes a third, previously unidentified carnitine acetyltransferase. The data also show that (a) L-carnitine and all three CATs are essential for growth on non-fermentable carbon sources in a strain with a disrupted CIT2 gene; (b) Yat2p contributes significantly to total CAT activity when cells are grown on ethanol; and that (c) the carnitine-dependent transfer of activated acetyl groups plays a more important role in cellular processes than previously realised.     

纽甜的合成方法

综述了新型强力甜味剂纽甜及其生产原料3,3-二甲基丁醛的合成方法。     

3D printed tooling for vacuum-assisted resin transfer moulding

Three-dimensional printing (3DP) is widely considered to be one of the low-cost additive manufacturing (AM) processes. In this paper, the suitability of 3DP for making tooling for the vacuum-assisted resin transfer moulding (VARTM) process is considered. This combination has potential advantages, since VARTM has significant prototyping benefits if it can be combined with a fast and low cost tooling option. This paper presents a new process chain for the manufacture of closed mould composite parts using the VARTM process. It will be shown that 3DP tooling is significantly less accurate than CNC machined tooling, but there is a cost and time advantage to making tooling with 3DP. The mould life is also limited to typically 15 to 30 parts since significant wear occurs in the manufacturing process. Quantitative data are presented to show the effect of treating the mould surface to improve the surface roughness and to determine the mould life. An aspect often lacking in AM research is cost estimation. Here, the first cost model for rapid tooling for VARTM using 3DP moulds is presented and compared to actual results. It is shown that the model is suitable for design for manufacture analysis.     

Study of Solidification Cracking in a Transformation-Induced Plasticity-Aided Steel

In situ high-temperature laser scanning confocal microscopy is applied to study solidification cracking in a TRIP steel. Solidification cracking was observed in the interdendritic region during the last stage of solidification. Atom probe tomography revealed notable enrichment of phosphorus in the last remaining liquid. Phase field simulations also confirm phosphorus enrichment leading to severe undercooling of more than 160 K in the interdendritic region. In the presence of tensile stress, an opening at the interdendritic region is difficult to fill with the remaining liquid due to low permeability and high viscosity, resulting in solidification cracking.     

An experimental technique employing a high-temperature gas-tight alumina seal for the assessment of the electrical properties of solid electrolytes

A technique is déscribed that permits the high-temperature gas-tight extension of short solid electrolyte tubes, discs or rods. It is demonstrated that this technique can be successfully used in the assessment, by coulometric titration, of mixed ionic and electronic conduction in the short solid electrolyte tubes that are commonly used in practical oxygen sensors.     

纳米碳管催化热解方法的制备及其微观结构的研究

通过乙炔气体在纳米铁颗粒上的催化热解制备了纳米碳管。利用电子显微镜对纳米碳管的形貌和结构进行了观察研究。发现纳米碳管具有分支生长的可能性，研究了纳米碳管管壁发生局部弯折的机理。     

PP用稳定剂1010和264国产化研究

本文研究了洛阳石化总厂PP厂所用两种进口稳定剂AE(1010)、AB(264)和同类型国产稳定剂对PP热老化性和加工稳定性的影响.结果表明,国产3~#1010和国产1~#264稳定剂对PP的长效稳定性和加工稳定性优于进口稳定剂,可以代替它们用于工业化生产.     

Estimation of energy balance and training volume during Army Initial Entry Training

Background

Adequate dietary intake is important for promoting adaptation and prevention of musculoskeletal injury in response to large volumes of physical training such as Army Initial Entry Training (IET). The purpose of this study was to evaluate training volume and dietary intake and estimate energy balance in Army IET soldiers.

Methods

Dietary intake was assessed by collecting diet logs for three meals on each of three, non-consecutive days during the first week of IET. Training volume was measured across 13?weeks of training using Actigraph wGT3X accelerometers. Training intensity was classified using Sasaki vector magnitude three cut points. Energy expenditure estimates were calculated during weeks two and three of training using the modified Harris-Benedict equation and by estimation of active energy expenditure using metabolic equivalents for each classification of physical activity. All data is presented as mean?±?standard deviation.

Results

A total of 111 male soldiers (ht. =?±?173?±?5.8?cm, age?=?19?±?2?years, mass?=?71.6. ± 12.4?kg) completed diet logs and were monitored with Actigraphs. IET soldiers performed on average 273?±?62?min low, 107?±?42?min moderate, 26?±?22?min vigorous, and 10?±?21?min of very vigorous intensity physical activity daily across 13?weeks. The estimated total daily energy expenditure was on average 3238?±?457 kcals/d during weeks two and three of IET. Compared to week one caloric intake, there was a caloric deficit of 595?±?896 kcals/d on average during weeks two and three of IET. Regression analysis showed that body weight was a significant predictor for negative energy balance (adj. R2?=?0.54, p?<?0.001), whereby a 1?kg increase in body mass was associated with a 53?kcal energy deficit.

Conclusions

Based on week one dietary assessment, IET soldiers did not consume adequate calories and nutrients to meet training needs during red phase (weeks one through three). This may directly affect soldier performance and injury frequency. IET soldiers undergo rigorous training, and these data may help direct future guidelines for adequate nourishment to optimize soldier health and performance.

     

SolTrack: an automatic video processing software for in situ interface tracking

High-Resolution in situ observation of solidification experiments has become a powerful technique to improve the fundamental understanding of solidification processes of metals and alloys. In the present study, high-temperature laser-scanning confocal microscopy (HTLSCM) was utilized to observe and capture in situ solidification and phase transformations of alloys for subsequent post processing and analysis. Until now, this analysis has been very time consuming as frame-by-frame manual evaluation of propagating interfaces was used to determine the interface velocities. SolTrack has been developed using the commercial software package MATLAB and is designed to automatically detect, locate and track propagating interfaces during solidification and phase transformations as well as to calculate interfacial velocities. Different solidification phenomena have been recorded to demonstrate a wider spectrum of applications of this software. A validation, through comparison with manual evaluation, is included where the accuracy is shown to be very high.