Effect of Bilayer Phospholipid Composition and Curvature on Ligand Transfer by the α-Tocopherol Transfer Protein

We report here our preliminary investigations on the mechanism of α-TTP-mediated ligand transfer as assessed using fluorescence resonance energy transfer (FRET) assays. These assays monitor the movement of the model α-tocopherol fluorescent derivative ((R)-2,5,7,8-tetramethyl-chroman-2-[9-(7-nitro-benzo[1,2,5]oxadiazol-4-yl amino)-nonyl]-chroman-6-ol; NBD-Toc) from protein to acceptor vesicles containing the fluorescence quencher TRITC-PE. We have found that α-TTP utilizes a collisional mechanism of ligand transfer requiring direct protein–membrane contact, that rates of ligand transfer are greater to more highly curved lipid vesicles, and that such rates are insensitive to the presence of anionic phospholipids in the acceptor membrane. These results point to hydrophobic features of α-TTP dominating the binding energy between protein and membrane. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. An erratum to this article can be found at     

SUV型无内胎子午线轮胎的设计

介绍SUV型无内胎子午线轮胎的设计。结构设计采取宽行驶面、小轮廓、减小胎圈着合直径、改进与轮辋配合处胎踵形状设计;胎面采用新研制的A／T型花纹及低生热、高速安全型胶料配方,胎侧采用优化白胎侧配方;优化胎圈施工条件。成品轮胎性能符合国家和国外相关标准。     

Energy use, cost and CO2 emissions of electric cars

We examine efficiency, costs and greenhouse gas emissions of current and future electric cars (EV), including the impact from charging EV on electricity demand and infrastructure for generation and distribution.Uncoordinated charging would increase national peak load by 7% at 30% penetration rate of EV and household peak load by 54%, which may exceed the capacity of existing electricity distribution infrastructure. At 30% penetration of EV, off-peak charging would result in a 20% higher, more stable base load and no additional peak load at the national level and up to 7% higher peak load at the household level. Therefore, if off-peak charging is successfully introduced, electric driving need not require additional generation capacity, even in case of 100% switch to electric vehicles.GHG emissions from electric driving depend most on the fuel type (coal or natural gas) used in the generation of electricity for charging, and range between 0 g km⁻¹ (using renewables) and 155 g km⁻¹ (using electricity from an old coal-based plant). Based on the generation capacity projected for the Netherlands in 2015, electricity for EV charging would largely be generated using natural gas, emitting 35-77 g CO_2 eq km⁻¹.We find that total cost of ownership (TCO) of current EV are uncompetitive with regular cars and series hybrid cars by more than 800 € year⁻¹. TCO of future wheel motor PHEV may become competitive when batteries cost 400 € kWh⁻¹, even without tax incentives, as long as one battery pack can last for the lifespan of the vehicle. However, TCO of future battery powered cars is at least 25% higher than of series hybrid or regular cars. This cost gap remains unless cost of batteries drops to 150 € kWh⁻¹ in the future. Variations in driving cost from charging patterns have negligible influence on TCO.GHG abatement costs using plug-in hybrid cars are currently 400-1400 € tonne⁻¹ CO_2 eq and may come down to −100 to 300 € tonne⁻¹. Abatement cost using battery powered cars are currently above 1900 € tonne⁻¹ and are not projected to drop below 300-800 € tonne⁻¹.     

聚焦民族品牌汽车SUV的设计理念研究

目的 以中国民族汽车品牌下的SUV汽车造型设计作为研究对象,通过案例分析,从造型基因、品牌意象,以及东西方汽车设计理念的视角,探究我国民族品牌汽车的设计思想.方法 选取国内外行业中具有设计代表性且已取得良好市场销量的汽车案例,分析汽车个体及其家族造型的设计特点与规律,对比东西方设计理念下的典型汽车设计案例,寻找适合中国民族品牌汽车的发展方向.结果 在东西方设计理念融合的大环境下,设计了一款具有东方民族意象感的汽车方案.结论 归纳总结出了一套适用于中国民族品牌汽车造型设计的理念与方法,对如何提升汽车自主品牌形象、传达中国民族文化、增强本土品牌汽车市场竞争力,具有一定程度的参考价值或启示性.     

Influences of pre-crash braking induced dummy – Forward displacements on dummy behaviour during EuroNCAP frontal crashtest

Combination of active and passive safety systems is a future key to further improvement in vehicle safety. Autonomous braking systems are able to reduce collision speeds, and therefore severity levels significantly. Passengers change their position due to pre-impact vehicle motion, a fact, which has not yet been considered in common crash tests. For this paper, finite elements simulations of crash tests were performed to show that forward displacements due to pre-crash braking do not necessarily increase dummy load levels. So the influence of different pre-crash scenarios, all leading to equal closing speeds in the crash phase, are considered in terms of vehicle motion (pitching, deceleration) and restraint system configurations (belt load limiter, pretensioner). The influence is evaluated by dummy loads as well as contact risk between the dummy and the interior.     

Isolation,characterization and antioxidant capacity assessment of the bioactive compounds derived from Hypoxis rooperi corm extract (African potato)

The rhizome of the plant Hypoxis rooperi (“African potato”) is known for its traditional and ethnomedical uses in the treatment of benign prostatic hyperplasia and other diseases. We have characterized an extract derived from H. rooperi, isolated its major bioactive compound, hypoxoside, and obtained its aglycone, rooperol, by enzymatic digestion. Absorption, fluorescence emission and bidimensional NMR complete spectral data of these compounds were obtained. The antioxidant capacity of both compounds was fully analyzed through the thiobarbituric acid reactive substances (TBARS) and Trolox equivalent antioxidant capacity (TEAC) assays, and it was compared to catechins and olive biophenolics. Both compounds showed a strong antioxidant capacity, although rooperol exhibited a higher antioxidant activity against lipid peroxidation which correlated to its strong affinity for phospholipid membranes as derived from its extremely high lipid/water partition coefficient (K_p = 3.4 × 10⁴). The study of the lipophilic (EtOH) and hydrophilic (water) TEAC values revealed that more hydrophobic compounds, had greater lipophilic TEAC values than hydrophilic ones, probably indicating that lipophilic TEAC assay may be more reliable for these compounds. The H. rooperi extract also showed higher antioxidant efficacy compared to other strong antioxidant herbal extracts, such as olive leaf or green tea. Moreover, neither evidence of acute oral toxicity nor adverse effects were observed when the H. rooperi commercial extract containing 45% hypoxoside was used at a dosage of 2000 mg/kg. The results obtained in this work may contribute to understanding the biological activity described for these dicatechols and the African potato extract for food and cosmetic applications.     

杆件布置对双叉臂前悬架性能影响的研究

依据多体系统动力学原理,建立某SUV轿车双叉臂独立前悬架的动力学模型,分析该悬架车轮定位参数随车轮跳动的变化情况.从改善整车操纵稳定性方面,结合对标车悬架试验结果,对该悬架的硬点进行灵敏度分析与优化设计,提高悬架性能.总结了杆件布置对双叉臂悬架性能影响的一般规律,为悬架设计提供参考依据.     

校正PET图像上病灶SUV值的研究

进行定量分析是PET技术重要的优势,但由于部分容积效应(PVE)的影响,使图像定量值失真.本研究建立一种校正PET图像上病灶标准摄取值(SUV)的方法.基于PET图像PVE形成原理及模拟实验,分析病灶图像上最大SUV与病灶真实大小、病灶真实SUV之间的关系,建立由图像上最大值校正SUV的方法,称之为最大值校正法.并通过PET模型实验,对建立的方法进行验证.结果:①最大值校正法:建立了用图像上病灶SUV最大值计算SUV校正值的公式.②实验验证:对不同大小的病灶,其SUV均得到了一定程度的校正,尤其对小于分辨率的病灶(4.7mm、3mm),校正效果更显著,SUV校正值的准确度提高了53.55%、54.17%和50.37%、68.52%.结论:建立了一种简单校正PET图像上病灶SUV的方法--最大值校正法.     

SUV车用"电喷"发动机废气涡轮增压技术初探

简要概述车用发动机废气涡轮增压技术的发展现状,针对近年来兴起的SUV(Sport Utility Vehicle)车,分析其采用废气涡轮增压的必要性和可行性,并对增压方案进行初步探讨。     

Effect of a heat release rate on reproducibility of fire test for hydrogen storage cylinders

The paper addresses the reproducibility of the fire test in the United Nations “Global technical regulation on hydrogen and fuel cell vehicles” (GTR#13) and similar fire test protocols in other regulations, codes and standards (RCS). Currently, GTR#13 requires controlling the flame temperature beneath the tank. An original Ulster conjugate heat transfer numerical model was applied to carry out a study demonstrating the dependence of a fire resistance rating (FRR) of a composite hydrogen tank on a fire heat release rate (HRR). No thermally activated pressure relief device was used. The validation experiments conducted afterwards at Karlsruhe Institute of Technology (KIT) plus a former USA fire test have confirmed the Ulster's conclusion to control not only temperatures, yet the fire HRR. This will improve the GTR#13 fire test reproducibility in different laboratories worldwide. The numerically observed variations of FRR were confirmed by the unique experimental data of the authors' collaborators: FRR = 16–22 min for HRR = 79 kW, 7–8 min (HRR = 165 kW) – both tests were carried out at KIT with identical 36 L volume and 700 bar pressure tanks; and 6–7 min (HRR = 370 kW), though this test in USA was performed with a larger volume tank of 72.4 L and 350 bar. The data on pool fire test with significantly higher HRR, i.e. 4100 kW, and tank volume of 100 L and 700 bar pressure confirmed the “saturation” effect in the dependence of FRR on HRR at HRR above 350 kW. The results of the study underpin the suggested amendment to GTR#13 to improve the reproducibility of the fire test and perform tests with onboard storage tanks at HRR>350 kW.