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.

We have developed a simplified heating and pulling method for formation of near-field scanning optical microscopy probing tips from optical fibers. Laser power and continuous pulling force are two key processing parameters investigated. We found a narrow working range of laser power of 1.85–1.95 W and the pulling force of 0.5–0.9 lb, with the optimum conditions of 1.90 W and 0.74 lb. Tips with short taper (∼300 μm), small apex (∼50 nm), and large aperture cone angles (∼45°) have been achieved. The as-prepared tips are subsequently bended by pulsed laser heating and metal coating. Digitized bending from 10° to 90° can be achieved by linearly adjustment of the laser dose. The fabricated tips have shown good light guiding.

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Formation of fine near-field scanning optical microscopy tips. Part II. By laser-heated pulling and bending

We present in this paper a novel method to fabricate fully three-dimensional (3D) microstructures and moving parts using a partially crosslinked polymer as sacrificial supports. This is realized on a projection microstereolithography (PµSL) which produces both the microstructure and the sacrificial part simultaneously using digital grayscale images. To establish the selectivity of the etchant to the partially crosslinked sacrificial parts, we measured the etching rate as a function of photo-crosslinking light intensity and the light exposure time. This technology may enable more complex scaffolds in tissue engineering and smart hydrogel devices.

http://iopscience.iop.org/article/10.1088/0960-1317/19/11/115029/pdf

Fully three-dimensional microfabrication with a grayscale polymeric self-sacrificial structure

In this paper, we report direct patterning of metal nanostructures using an embossed solid electrochemical stamp. Microforming of solid superionic stamps using Si templates—analogous to polymer patterning in nano-imprint lithography—is explored. Silver sulfide (Ag2S)—a superionic conductor with excellent microforming properties—is investigated as a candidate material. Important parameters of the superionic stamp, including mechanical behavior, material flow during forming and feature recovery after embossing, are studied. Excellent feature transferability during embossing as well as etching is observed. To illustrate the capability of this approach silver nano-antennas with gaps 6 mm is also demonstrated. Embossing-based metal patterning allows fabrication beyond two-dimensional nanofabrication and several patterning schemes are reported.

https://iopscience.iop.org/article/10.1088/0957-4484/22/15/155302/pdf

Direct metal nano-imprinting using an embossed solid electrolyte stamp.

Previous acoustic cloaks designed with transformation acoustics always involve inhomogeneous material. In this paper, a design of acoustic polygonal cloak is proposed using linear polygonal transformation method. The designed acoustic polygonal cloak has homogeneous and anisotropic parameters, which is much easier to realize in practice. Furthermore, a possible acoustic metamaterial structure to realize the cloak is proposed. Simulation results on the real structure show that the metamaterial acoustic cloak is effective to reduce the scattering of the object.

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A broadband polygonal cloak for acoustic wave designed with linear coordinate transformation

The present invention provides an electrochemical fabrication platform for making structures, arrays of structures and functional devices having selected nanosized and/or microsized physical dimensions, shapes and spatial orientations. Methods, systems and system components of the present invention use an electrochemical stamping tool for generating patterns of relief and/or recessed features exhibiting excellent reproducibility, pattern fidelity and resolution on surfaces of solid state ionic conductors and in metal. Electrochemical stamping tools of the present invention are capable high throughput patterning of large substrate areas and, thus, enable a robust and commercially attractive manufacturing pathway to a range of functional systems and devices including nano- and micro-electromechanical systems, sensors, energy storage devices and integrated electronic circuits.

Nicholas X. Fang

Papers

Formation of fine near-field scanning optical microscopy tips. Part II. By laser-heated pulling and bending

Fully three-dimensional microfabrication with a grayscale polymeric self-sacrificial structure

Direct metal nano-imprinting using an embossed solid electrolyte stamp.

A broadband polygonal cloak for acoustic wave designed with linear coordinate transformation

Pattern transfer by solid state electrochemical stamping