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

A model system for investigating the formation of electromigration damage and the electromigration lifetime of thin film metallizations has been developed. This system contains fast diffusing segments consisting of plastically deformed regions created by nanoindentation in single-crystal pure Al conductor lines. These segments mimic the behavior of polygranular segments in lines having “near-bamboo” grain structure. We have used these model systems to investigate critical length effects and segment interaction effects, as well as the nucleation and evolution of electromigration voids as a function of orientation. Void nucleation is shown to depend on segment length and current density and segments are shown to interact to nucleate electromigration damage. Electromigration void evolution and electromigration lifetimes are shown to depend strongly on the crystallographic orientation of the conductor lines.

Model studies of electromigration using indented single-crystal aluminum lines

We have simulated the development of grain structures in polycrystalline films with lognormally distributed grain sizes, and carried out extensive characterization of grain cluster and bamboo cluster statistics. These statistics were characterized as a function of line-width to initial-grain-size ratios in as-patterned strips, and in strips in which we have simulated post-patterning grain structure evolution resulting from annealing. Among the important findings is that polygranular and bamboo cluster-length distributions for as-patterned lines are best fit by Weibull distribution functions instead of lognormal or exponential functions, as is often assumed. We report analytic formulae describing grain structure statistics that can be used in reliability calculations and simulations. We have carried out structure-sensitive electromigration simulations to show that the predicted failure statistics are essentially the same for grain structures generated using grain growth simulations and grain structures generated using analytic models. Analytic models provide computationally efficient means of determining the lifetime variations associated with grain-structure variations.

Grain Structure Statistics in As-Patterned and Annealed Interconnects

Response to “Comment on ‘Correlation of shape changes of grain surfaces and reversible stress evolution during interruptions of polycrystalline film growth’” [Appl. Phys. Lett. 105, 246101 (2014)]

Uncertainty about future energy and water supplies suggests a pressing need to develop efficient technologies for water desalination. Capacitive deionization (CDI), a method that captures ions in the electrical double layer (EDL) of an electrochemical capacitor, is a promising technology that can potentially fulfill those requirements. Similar to supercapacitors, ideal CDI electrodes should have a large electrolyte-accessible specific surface area available for ion adsorption with rapid charging/discharging characteristics. Unlike supercapacitors, CDI electrodes are required to operate in aqueous electrolytes with low ionic concentrations in a non-linear charging regime. To explore this practically and theoretically important regime, we developed robust, electrochemically-compatible carbon nanotube (CNT) carpet electrodes that posses a well-defined and uniform pore structure that is more readily analyzed in comparison to the random and multi-scale pore structure of typical carbon electrodes. The fabricated electrodes were characterized using cyclic voltammetry and potentiostatic charging in aqueous NaCl solutions (no = 20 - 90 mM) using a three electrode setup. Examination of the CV and potentiostatically-measured capacitances were consistent with EDL behavior dictated by the Stern layer. However, some deviations from the expected behavior were observed with increasing salt concentration during potentiostatic testing.

Diffusion-bonded CNT carpets for fundamental CDI studies

Understanding the origin of substantial performance challenges limiting the practical development of Li–O2 batteries, such as low rate capability, limited cycle life (<100 cycles), and the large voltage polarization (0.6–1 V) on charge, requires improved understanding of chemical, electrochemical, morphological, and electronic processes occurring in the electrode. This chapter highlights current understanding of how the kinetics and reaction product characteristics in Li–O2 batteries during discharge and charge influence performance characteristics at the cell level. First, a brief overview of energy and power of various Li–O2 electrodes reported in the literature to date is presented for a range of O2 electrode materials and designs as a benchmark for what has been achieved at the laboratory scale. Next, we review chemical and morphological understanding of the oxygen reduction (discharge) process, with a particular focus on nanostructured carbon electrodes in 1,2-dimethoxyethane (DME) electrolyte. The kinetics of oxygen reduction and the influence of kinetics on the morphology and shape evolution of Li2O2 are discussed, including recent insights into the microscale structure and proposed growth mechanisms of “toroidal” crystalline Li2O2 at low currents or overpotentials. We next discuss the surface chemistry of discharged oxygen electrodes, including the morphology-dependent surface chemistry of Li2O2, reactivity between Li2O2 and the carbon electrode, reactivity between Li2O2 and ether-based electrolytes, and resulting parasitic products that form upon discharge and during subsequent cycling. In light of chemical instabilities present nearly universally in liquid cells, we highlight recent work utilizing in situ ambient pressure XPS (APXPS) to examine Li–O2 electrochemistry during battery operation in an all-solid-state cell. Finally, we discuss the influence of morphology and surface chemistry of the discharge product on the charging kinetics in carbon-nanostructured electrodes, where morphology-dependent Li2O2 surface chemistry and structure are found to significantly influence the overpotential required during oxidation. Combined chemical, electrochemical, morphological, and electronic understanding is increasingly important as researchers seek to develop improved O2 electrodes with increased round-trip efficiency and improved chemical/electrochemical reversibility approaching what is needed for practical devices.

Carl V. Thompson

Papers

Model studies of electromigration using indented single-crystal aluminum lines

Grain Structure Statistics in As-Patterned and Annealed Interconnects

Response to “Comment on ‘Correlation of shape changes of grain surfaces and reversible stress evolution during interruptions of polycrystalline film growth’” [Appl. Phys. Lett. 105, 246101 (2014)]

Diffusion-bonded CNT carpets for fundamental CDI studies

The Kinetics and Product Characteristics of Oxygen Reduction and Evolution in LiO2 Batteries