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

Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons--in particular their interaction with light--can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.

/pdf/surface-plasmon-subwavelength-optics-5e55p12p4o.pdf

Surface plasmon subwavelength optics

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

Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.

Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?

The unprecedented ability of nanometallic (that is, plasmonic) structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavours. Plasmonic light concentrators can elegantly interface diffraction-limited dielectric optical components with nanophotonic structures. Passive and active plasmonic devices provide new pathways to generate, guide, modulate and detect light with structures that are similar in size to state-of-the-art electronic devices. With the ability to produce highly confined optical fields, the conventional rules for light-matter interactions need to be re-examined, and researchers are venturing into new regimes of optical physics. In this review we will discuss the basic concepts behind plasmonics-enabled light concentration and manipulation, make an attempt to capture the wide range of activities and excitement in this area, and speculate on possible future directions.

/pdf/plasmonics-for-extreme-light-concentration-and-manipulation-25m55spiva.pdf

Plasmonics for extreme light concentration and manipulation.

We present a new practical scheme to study the spectroscopic properties of molecules embedded in optically complex surroundings. The response function accounting for the modification of the spectroscopic behavior of the molecules is derived self-consistently in direct space through the numerical solution of Dyson's equation. We apply this scheme to investigate near-field optical effects due to fluorescence phenomena. Experimentally relevant examples show that the dramatic decay of the molecular lifetime upon approaching a surface defect could achieve well-resolved imaging of subwavelength structures.

/pdf/molecular-lifetime-changes-induced-by-nanometer-scale-95qsbmyk0s.pdf

Molecular lifetime changes induced by nanometer scale optical fields.

Keywords: Nanophotonics, Plasmonics Reference EPFL-CONF-175036 Record created on 2012-02-21, modified on 2017-05-10

Controlling the interaction between localized and delocalized surface plasmon modes

We exploit the versatility provided by metal-dielectric composites to demonstrate controllable coherent perfect absorption (CPA) or anti-lasing in a slab of heterogeneous medium The slab is illuminated by coherent light from both sides, at the same angle of incidence and the conditions required for CPA are investigated as a function of the different system parameters Our calculations clearly elucidate the role of absorption as a necessary prerequisite for CPA We further demonstrate the controllability of the CPA frequency to the extent of having the same at two distinct frequencies even in presence of dispersion, rendering the realization of anti-lasers more flexible

Controllable coherent perfect absorption in a composite film

We study experimentally and numerically a novel three-dimensional magnetic resonator structure with high isotropy. It is formed by crossed split-ring resonators and has a response independent of the illumination direction in a specific plane. The utilization of such elements to build a finite left-handed medium is discussed.

Efficient isotropic magnetic resonators

The relation between the near–field and far–field properties of plasmonic nanostructures that exhibit Fano resonances is investigated in detail. We show that specific features visible in the asymmetric lineshape far–field response of such structures originate from particular polarization distributions in their near–field. In particular we extract the central frequency and width of plasmonic Fano resonances and show that they cannot be directly found from far–field spectra. We also address the effect of the modes coupling onto the frequency, width, asymmetry and modulation depth of the Fano resonance. The methodology described in this article should be useful to analyze and design a broad variety of Fano plasmonic systems with tailored near–field and far–field spectral properties.

Olivier J. F. Martin

Papers

Molecular lifetime changes induced by nanometer scale optical fields.

Controlling the interaction between localized and delocalized surface plasmon modes

Controllable coherent perfect absorption in a composite film

Efficient isotropic magnetic resonators

Relation between near–field and far–field properties of plasmonic Fano resonances