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

The emerging field of plasmonics has yielded methods for guiding and localizing light at the nanoscale, well below the scale of the wavelength of light in free space. Now plasmonics researchers are turning their attention to photovoltaics, where design approaches based on plasmonics can be used to improve absorption in photovoltaic devices, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers, and yielding new options for solar-cell design. In this review, we survey recent advances at the intersection of plasmonics and photovoltaics and offer an outlook on the future of solar cells based on these principles.

Plasmonics for improved photovoltaic devices

Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields-electric displacement field D, magnetic induction field B, and Poynting vector B-are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.

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Controlling Electromagnetic Fields

Fundamentals of Plasmonics.- Electromagnetics of Metals.- Surface Plasmon Polaritons at Metal / Insulator Interfaces.- Excitation of Surface Plasmon Polaritons at Planar Interfaces.- Imaging Surface Plasmon Polariton Propagation.- Localized Surface Plasmons.- Electromagnetic Surface Modes at Low Frequencies.- Applications.- Plasmon Waveguides.- Transmission of Radiation Through Apertures and Films.- Enhancement of Emissive Processes and Nonlinearities.- Spectroscopy and Sensing.- Metamaterials and Imaging with Surface Plasmon Polaritons.- Concluding Remarks.

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Plasmonics: Fundamentals and Applications

We present the design for an absorbing metamaterial (MM) with near unity absorbance A(omega). Our structure consists of two MM resonators that couple separately to electric and magnetic fields so as to absorb all incident radiation within a single unit cell layer. We fabricate, characterize, and analyze a MM absorber with a slightly lower predicted A(omega) of 96%. Unlike conventional absorbers, our MM consists solely of metallic elements. The substrate can therefore be optimized for other parameters of interest. We experimentally demonstrate a peak A(omega) greater than 88% at 11.5 GHz.

Perfect metamaterial absorber.

In this invited talk, we report the experimental investigation of hybrid meta-gel, a class of designed hydrogel composites with tunable acoustic properties over broadband frequencies. The meta-gel consists of patterned channels in a tough hydrogel matrix, where air, water, or liquid metal can be purged through the channels to tune the meta-gel’s acoustic transmission over broadband frequencies on demand. We show that the acoustic properties of the meta-gel can be tuned by varying the volume ratio of the channels, properties and ratio of the different filler materials with combined experiments, theory, and simulations. We validated that the hybrid metamaterial significantly increased directivity and main lobe energy over a broad bandwidth both numerically and experimentally. The meta-gel enables novel functions such as adjustable imaging regions of ultrasound, demonstrating tangible applications in underwater acoustics and medical imaging.

Soft acoustic metamaterials: From broadband tunable metagels to directional emission

Based on a planar structure comprising of a metal/dielectric multilayer stack and a thick metal substrate layer, we have obtained an omnidirectional, polarization-insensitive and multiband thin absorber in the visible regime.

Multiband electromagnetic absorbers based on a metal/dielectric multilayer stack

Modeling of charge-mass transport in solid electrolyte-based electrochemical nanomanufacturing process

We demonstrated high-resolution pixelated quantum dots (QDs)/thiol-ene photopolymer color converters patterned by projection lithography on microLEDs The material composite and patterning technology enable high-efficiency, wide-gamut and low cross-talk color conversion compared to drop-cast QDs

Quantum Dots Color Converters for MicroLEDs: Material Composite and Patterning Technology

We demonstrate the ability to create ‘liquid-walls’ in hydrophilic microfluidic channels, without the need for hydrophobic patterning. This is achieved by stopping the liquid using sudden expansion in cross-section perpendicular to the flow direction. Further, these walls can be switched off dynamically either manually or by using simple microfluidic logic. The maximum break pressure for these walls is determined by the surface free energy of the liquid, the advancing contact angle of the liquid on substrate and the channel geometry. This system can be used in liquid-gas chemical reactors, passive microfluidic valves, microfluidic pressure switches and in eliminating air entrapment issues.Copyright © 2008 by ASME

Nicholas X. Fang

Papers

Soft acoustic metamaterials: From broadband tunable metagels to directional emission

Multiband electromagnetic absorbers based on a metal/dielectric multilayer stack

Modeling of charge-mass transport in solid electrolyte-based electrochemical nanomanufacturing process

Quantum Dots Color Converters for MicroLEDs: Material Composite and Patterning Technology

Flow Inside Microchannels With Liquid-Walls