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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

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

Diamond-like carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC is a semiconductor with a high mechanical hardness, chemical inertness, and optical transparency. This review will describe the deposition methods, deposition mechanisms, characterisation methods, electronic structure, gap states, defects, doping, luminescence, field emission, mechanical properties and some applications of DLCs. The films have widespread applications as protective coatings in areas, such as magnetic storage disks, optical windows and micro-electromechanical devices (MEMs).

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Diamond-like amorphous carbon

Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid–solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime—experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management of optoelectronic devices have stimulated extensive studies of semiconductor superlattices; agreement between experiment and theory is generally poor. Advances in measurement methods, e.g., the 3ω method, time-domain thermoreflectance, sources of coherent phonons, microfabricated test structures, and the scanning thermal microscope, are enabling new capabilities for nanoscale thermal metrology.

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Nanoscale thermal transport

This letter demonstrates a method for fabricating single-crystal Si nanolines, with rectangular cross sections and nearly atomically flat sidewalls. The high quality of these nanolines leads to superb mechanical properties, with the strain to fracture measured by nanoindentation tests exceeding 8.5% for lines of 74 nm width. A large displacement burst before fracture was observed, which is attributed to a buckling mechanism. Numerical simulations show that the critical load for buckling depends on the friction at the contact surface.

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Fabrication and Characterization of Patterned Single-Crystal Silicon Nanolines

General aspects of barrier layers for very-large-scale integration applications I: Concepts

The ambient gas effect in SiOx-based resistive switching memory has been studied. After the electroforming process, resistive switching behavior functions in vacuum as well as in nitrogen without dramatic degradation. However, introducing an oxygen-nitrogen ambient suppresses resistive switching behavior at pressures above 1 Torr. Resistive switching is fully reestablished in oxygen-exposed devices after a vacuum recovery step. The failure phenomena can be described by Monte Carlo simulation using bi-modal statistics to enable feature distribution modeling of failure modes. Design criteria and guidelines are identified for packaging of future oxygen-sensor and of nonvolatile memory applications.

Oxygen-induced bi-modal failure phenomenon in SiOx-based resistive switching memory

The kinetics of the solute effect on solvent electromigration and the vacancy-flow effect on solute electromigration have been analyzed. The Howard and Manning type analysis has been applied to the diffusion data of a number of solutes in Al, Cu, Ag, and Au for determining the required jumping-frequency ratios. The cross-term contributions to the electromigration flux are found to be negative for all the solutes analyzed, so the vacancy-flow effect reduces solute and solvent migration. However, the enhanced diffusivity of the solvent and the large effective charge of the solute overcompensate the negative vacancy-flow corrections. As a result, most of the solutes analyzed are predicted to enhance solvent electromigration except for Fe in Cu and Ag. The result is attributed to the particular behavior of the vacancy jumping around the impurity. Of particular interest also is that the predicted effect of Cu on Al in bulk crystal is inconsistent with the existing thin-film observations.

Solute effects on electromigration

The ball-on-ring (BOR) and three-point bending (3PB) tests were used in this paper to characterize the effect of the dicing process on the fracture strength of Si dies. Dies prepared by blade- and laser-dicing processes were studied. The edge-initiated fracture was distinguished from the surface-initiated fracture by fractographic analysis. The fracture-strength distributions related to surface flaws in the 3PB test, as well as the BOR test, were consistent regardless of the dicing process. For the edge-defect-induced failure mode, on the other hand, blade-sawn dies showed wider spread distribution than laser-sawn dies. It was due to the scattered nature in size and location of the edge flaws induced by blade dicing. Laser-sawn dies showed a tighter distribution of die strength, although the average die strength was slightly lower than that of blade-sawn dies. This paper has successfully demonstrated that the die failure caused by edge defects can be deconvoluted from the 3PB test data by using fractographic observation.

Paul S. Ho

Papers

Fabrication and Characterization of Patterned Single-Crystal Silicon Nanolines

General aspects of barrier layers for very-large-scale integration applications I: Concepts

Oxygen-induced bi-modal failure phenomenon in SiOx-based resistive switching memory

Solute effects on electromigration

Effect of Dicing Technique on the Fracture Strength of Si Dies With Emphasis on Multimodal Failure Distribution