Electron capture dissociation as structural probe for noncovalent gas-phase protein assemblies

Electron capture dissociation (ECD) of proteins in Fourier transform ion cyclotron resonance mass spectrometry usually leads to charge reduction and backbone-bond cleavage, thereby mostly retaining labile, intramolecular noncovalent interactions. In this report, we evaluate ECD of the 84-kDa noncovalent heptameric gp31 complex and compare this with sustained off-resonance irradiation collisionally activated dissociation (SORI-CAD) of the same protein. Unexpectedly, the 21+ charge state of the gp31 oligomer exhibits a main ECD pathway resulting in a hexamer and monomer, disrupting labile, intermolecular noncovalent bonds and leaving the backbone intact. Unexpectedly, the charge separation over the two products is highly proportional to molecular weight. This indicates that a major charge redistribution over the subunits of the complex does not take place during ECD, in contrast to the behavior observed when using SORI-CAD. We speculate that the ejected monomer retains more of its original structure in ECD, when compared to SORI-CAD. ECD of lower charge states of gp31 does not lead to dissociation of noncovalent bonds. We hypothesize that the initial gas-phase structure of the 21+ charge state is significantly different from the lower charge states. These structural differences result in the different reaction pathways when using ECD.     

Large area, 38 nm half-pitch grating fabrication by using atomic spacer lithography from aluminum wire grids

We wrapped 150 nm period aluminum wire grid polarizer (WGP) with AlSiOx by using atomic layer deposition at 250 degrees C. The nanometer precision coating defined the spacer to double the spatial frequency of the 100 mm diameter grating fabricated by using a legacy immersion holography setup at 351 nm wavelength. Half-pitch grating of approximately 38 nm was demonstrated with good pattern uniformity, excellent repeatability, and a wide processing window. We believe 10 nm half-pitch grating over even larger areas are viable, overcoming one major hurdle to commercialize nanoimprint.     

Combination hemodialysis and centrifugal therapeutic plasma exchange: 18 years of Canadian experience

Hemodialysis (HD) and therapeutic plasma exchange (TPE) are extracorporeal treatments that may both be required in the same patient. When provided separately, 7–8 hours of therapy time is required. Simultaneous administration of both therapies can reduce time and personnel requirements. We report our 18‐year institutional experience with combination HD and centrifugal TPE therapy. During combination therapy, the TPE circuit is attached to the HD circuit through an extension blood line connected to the HD venous return line, allowing simultaneous operation of both circuits. The HD circuit is anticoagulated with heparin and the TPE circuit with regional citrate. Blood flow rates through the HD circuit can reach 350 mL/min with plasma removal rates in the TPE circuit up to 60 mL/min. Ninety‐two patients received a total of 621 treatments between December 1993 and July 2011. All treatments were completed within 4 hours. No major treatment‐related adverse events occurred and less than 10% of treatments were complicated by minor events. Main indications for treatment were ANCA (anti‐neutrophilic cytoplasmic antibody) vasculitis (n = 25), Goodpasture's/antiglomerular basement membrane disease (n = 24), adult thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (n = 24), and acute antibody‐mediated renal transplant rejection (n = 8). Overall rates of renal recovery, in‐hospital mortality, and overall mortality at 18‐year follow‐up were 45% (41/ 92), 2% (2/92), and 21% (19/ 92), respectively, compatible with published literature. Combination HD and TPE is safe, efficient, and requires less human resources and time than conventional sequential therapy. It should be considered in patients whose treatment regimen includes HD and TPE.     

Creating resilient and sustainable manufacturing businesses – a conceptual fitness model

Over recent years, UK manufacturing industry has experienced turbulence in its business performance. Lower cost products, and responsive and flexible processes, are now essential in order for a company to capture new markets and to become economically resilient. Business resiliency is a term used frequently to describe a company’s ability to adapt and cope with disturbance. This has led to the generation of many frameworks and models aimed at guiding companies towards improved business performance. However, these frameworks are primarily strategic in nature and do not necessarily focus on creating resilience at an operational level in manufacturing companies. The authors employ a mixed research approach initially undertaking a literature review and then a screening survey in to 25 manufacturing companies in order to identify the key business resiliency techniques employed. Following this, a focus group goes on to detail a new manufacturing resiliency model called the fit operational model. The model’s effectiveness is then assessed and adjusted as a result of being implemented in a subject company.     

基于NEMA协议的DALI照明系统研究进展

前言在数字可寻址接口(DALI)镇流器协议被正式纳入国际荧光灯镇流器标准之后,来自美国国家电气制造商协会(NEMA)照明控制分会、镇流器分会、灯具分会和布线装置分会的代表们开始了对一种适用于照明控制装置如墙壁开关、现场开关、占用式传感器和光传感器的附加性DALI协议的开发     

Emissions from large-scale medium-speed diesel engines: 3. Influence of direct water injection and common rail

The influence of direct water injection (DWI) on emissions from a multivariable large-scale (6–18 cyl, ~ 1 MW/cyl) diesel engine is reported, using a combined injection valve and nozzle that allows for injection of water and fuel oil into the cylinder. This method allows for injecting a relatively large amount of water without derating the engine power and NO_x emissions can be more than halved by DWI. Indeed DWI decreases combustion temperatures and NO_x emissions, but it gives somewhat increased (yet not problematic) emissions of CO, HC, soot (smoke) and particulate matter (PM), depending on the water injection timing and degree of incomplete combustion.     

Improvement of an Acid Phosphatase/DHAP‐Dependent Aldolase Cascade Reaction by Using Directed Evolution

To enhance the phosphorylating activity of the bacterial nonspecific acid phosphatase from Salmonella enterica ser. typhimurium LT2 towards dihydroxyacetone (DHA), a mutant library was generated from the native enzyme. Three different variants that showed enhanced activity were identified after one round of epPCR. The single mutant V78L was the most active and showed an increase in the maximal DHAP concentration to 25 % higher than that of the wild‐type enzyme at pH 6.0. This variant is 17 times more active than the wild‐type acid phosphatase from Salmonella enterica ser. typhimurium LT2 in the acid phosphatase/aldolase cascade reaction at pH 6.0 and is also six times more active than the phosphatase from Shigella flexneri that we previously used.     

电场感知技术应用

拉斯维加斯的演出节目和客车的安全系统会有什么相关之处呢?如果看了“Penn&Teller”的魔术表演,你就会产生一些灵感了。Elesys公司的PhilRittmueller就是这样--Elesys公司以前曾是NEC的一部分,Phil的主意可以用于汽车安全气囊的触发控制,以避免对幼龄乘客可能造成的严重伤害甚至死亡。想象一下,当“Penn&Teller”的PennGillette坐在“心灵座椅“之中—那是一把综合了光学和电子学的旧式木椅—指挥着一个管弦乐队。Penn仅仅通过身体的动作,就能分别让各式各样的乐器表演起来。他的动作是非常夸张的,超过了真正乐队的指挥。当他跺脚的…