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

Conventional heteroepitaxial thin film growth may result in a film whose epitaxial orientation is metastable. One method of probing the relative energies of various film orientations is epitaxial grain growth. Epitaxial grain growth selects the orientation having lowest total free energy, including the free energy of both the film-substrate interface and the free surface of the film. Experimental examples of epitaxial grain growth in metal films on insulating substrates will be discussed.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S194642740039621X

Epitaxial Grain Growth and Orientation Metastability in Heteroepitaxial Thin Films

A tool for simulation of electromigration and electromigration-induced damage, MIT/EmSim, has been used to investigate interconnect reliability, focusing on transitions in failure mechanisms associated with void nucleation, growth, and growth saturation. Conventional scaling of electromigration test results assume that the median time to electromigration-induced failure scales with the current density j to the power -n. The effects of transitions in failure mechanisms have been studied by characterizing the apparent current density exponent. When failure is limited by void nucleation, n=2 scaling is observed, and when failure requires substantial void growth, n=1 scaling is observed. When lines end at diffusion barriers such as W or liner-filled vias, void growth saturates in short lines at low current densities, and, depending on the failure criterion, lines under these conditions can be ‘immortal’. As growth saturates, apparent current density exponents increase above 2. Failure mechanism maps can be constructed to illustrate the failure mechanisms and scaling behavior as a function of line length and current density. Failure maps can be used in accurately scaling test results to service conditions, to suggest layout strategies for optimized circuit reliability, and to assess the reliability of new interconnect materials and structures.

Interconnect Failure Mechanism Maps for Different Metallization Materials and Processes

ZnO was electrodeposited on single-crystal, highly (111) textured polycrystalline, and randomly aligned polycrystalline Au films serving as the cathodes. The electrodeposition was carried out in a zinc nitrate aqueous solution at 65°C. The morphologies and crystal structures of ZnO were closely related to the properties of the Au surface. A detailed analysis was conducted, and the conclusion is that while the structural properties of ZnO can be controlled by controlling the crystal properties of Au film, the optical properties of ZnO are similar under the same electrodeposition conditions. However, using a two-step electrodeposition, smooth and compact epitaxial ZnO films are obtained.

A Study on Morphology Control of ZnO Electrodeposited on Au Surface

Erratum: “In situ tensile and creep testing of lithiated silicon nanowires” [Appl. Phys. Lett. 103, 263906 (2013)]

In Cu metallization, refractory metal liners at vias generally block electromigration. As liner thicknesses are decreased, fully-blocking liners at vias become less certain due to liner ruptures. We have developed and exercised a reliability CAD tool, SysRel, for circuit-level interconnect reliability assessments, and used it to assess the impact of non-blocking vias on circuit-level reliability with Cu metallization. SysRel utilizes a hierarchical reliability analysis with fundamental reliability units that sufficiently captures the differences in electromigration failure between Al and Cu metallization. This paper is the first discussion of its application to real circuit elements, to investigate the impact of non-blocking vias on circuit-level reliability. As observed in a 32-bit comparator circuit layout, the presence of non-blocking vias leads to an overall reduction in the number of mortal trees and to an increase in the effective length of the mortal trees. Full-chip reliability degrades if electromigration lifetime is treated as a strong function of line length.

Carl V. Thompson

Papers

Epitaxial Grain Growth and Orientation Metastability in Heteroepitaxial Thin Films

Interconnect Failure Mechanism Maps for Different Metallization Materials and Processes

A Study on Morphology Control of ZnO Electrodeposited on Au Surface

Erratum: “In situ tensile and creep testing of lithiated silicon nanowires” [Appl. Phys. Lett. 103, 263906 (2013)]

Impact of Non-blocking Vias on Electromigration and Circuit-level Reliability Assessments of Cu Interconnects