抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Li-ion batteries have transformed portable electronics and will play a key role in the electrification of transport. However, the highest energy storage possible for Li-ion batteries is insufficient for the long-term needs of society, for example, extended-range electric vehicles. To go beyond the horizon of Li-ion batteries is a formidable challenge; there are few options. Here we consider two: Li-air (O(2)) and Li-S. The energy that can be stored in Li-air (based on aqueous or non-aqueous electrolytes) and Li-S cells is compared with Li-ion; the operation of the cells is discussed, as are the significant hurdles that will have to be overcome if such batteries are to succeed. Fundamental scientific advances in understanding the reactions occurring in the cells as well as new materials are key to overcoming these obstacles. The potential benefits of Li-air and Li-S justify the continued research effort that will be needed.

Li-O2 and Li-S batteries with high energy storage.

Microstructures and properties of high-entropy alloys

Energy-storage technologies, including electrical double-layer capacitors and rechargeable batteries, have attracted significant attention for applications in portable electronic devices, electric vehicles, bulk electricity storage at power stations, and “load leveling” of renewable sources, such as solar energy and wind power. Transforming lithium batteries and electric double-layer capacitors requires a step change in the science underpinning these devices, including the discovery of new materials, new electrochemistry, and an increased understanding of the processes on which the devices depend. The Review will consider some of the current scientific issues underpinning lithium batteries and electric double-layer capacitors.

Challenges Facing Lithium Batteries and Electrical Double‐Layer Capacitors

Focused‐ion‐beam‐induced deposition of a low resistivity Cu film has been produced using local heating of the substrate with a semiconductor laser. A spot of order 70 μm diameter is irradiated using suitable optics to couple the 1.3 W, 977 nm laser radiation to the sample. The resistivity of the deposited Cu drops from 150–200 μΩ cm with no laser power to 3 μΩ cm at 1.2 W, when the temperature in the irradiated areas is 120 °C. The metal film deposits only where the ion beam is incident.

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Laser-assisted focused-ion-beam-induced deposition of copper

/pdf/kinetic-study-of-the-initial-lithiation-of-amorphous-silicon-1vy5dk4u25.pdf

Kinetic Study of the Initial Lithiation of Amorphous Silicon Thin Film Anodes

Failure of the tungsten-filled via interconnect structure is modelled. Two mechanisms contributing to void growth are considered: relief of stress due to differential thermal expansion, and electromigration. A self-limiting void volume is predicted, resulting in a self-limiting resistance increase which is a function of structure geometry and the void morphology. The relative contributions of the two mechanisms change significantly as the temperature and current density are reduced from accelerated test conditions, affecting the extrapolation of test results to service conditions. Modified procedures for extrapolating lifetimes are discussed, as well as suggested process changes to improve reliability.

Failure in Tungsten-Filled Via Structures

The electromigration lifetime of dual-damascene Cu interconnects was found to significantly decrease with increasing linewidth, for linewidths ranging between 0.2 and 2.25μm. Voids were also found to preexist in these lines. When void nucleation is required for failure, the electromigration reliability is generally found to be at most weakly dependent on the linewidth. In contrast, the current study suggests that growth, drift, and accumulation of existing voids lead to the observed strong linewidth dependence.

Effects of microvoids on the linewidth dependence of electromigration failure of dual-damascene copper interconnects

The effects of the surface roughness and applied loads on the specific electrical contact resistance of three-dimensional Cu–Cu bonded interconnects have been quantitatively investigated. Wafer-level thermocompression bonding was carried out on bonded Cu layers with either different surface roughness at a certain load or with similar surface roughness at different applied loads. Experimental results show that as the surface roughness of the Cu bonding layer increases or as the bonding load decreases, the specific contact resistance of the bonded interconnects increases. A model is presented which quantifies the relationship between the specific contact resistance and the true contact area (which is a function of the surface roughness and applied load). Through the true contact area, the integrity of a bonded interface may be predicted from the electrical measurement of the contact resistance.

/pdf/experimental-characterization-and-modeling-of-the-contact-1bhphwnn6d.pdf

Carl V. Thompson

Papers

Laser-assisted focused-ion-beam-induced deposition of copper

Kinetic Study of the Initial Lithiation of Amorphous Silicon Thin Film Anodes

Failure in Tungsten-Filled Via Structures

Effects of microvoids on the linewidth dependence of electromigration failure of dual-damascene copper interconnects

Experimental characterization and modeling of the contact resistance of Cu–Cu bonded interconnects