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

Two organolead halide perovskite nanocrystals, CH3NH3PbBr3 and CH3NH3PbI3, were found to efficiently sensitize TiO2 for visible-light conversion in photoelectrochemical cells. When self-assembled on mesoporous TiO2 films, the nanocrystalline perovskites exhibit strong band-gap absorptions as semiconductors. The CH3NH3PbI3-based photocell with spectral sensitivity of up to 800 nm yielded a solar energy conversion efficiency of 3.8%. The CH3NH3PbBr3-based cell showed a high photovoltage of 0.96 V with an external quantum conversion efficiency of 65%.

Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells

Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

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Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Current research into semiconductor clusters is focused on the properties of quantum dots-fragments of semiconductor consisting of hundreds to many thousands of atoms-with the bulk bonding geometry and with surface states eliminated by enclosure in a material that has a larger band gap. Quantum dots exhibit strongly size-dependent optical and electrical properties. The ability to join the dots into complex assemblies creates many opportunities for scientific discovery.

Semiconductor Clusters, Nanocrystals, and Quantum Dots

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Quantization effects in the photocurrent spectroscopy of superlattice electrodes

Solar cells and methods for use and making these solar cells are disclosed An exemplary solar cell includes a first electrode The solar cell also includes a nanocrystal film of a single material disposed in contact with the first electrode The solar cell also includes a second electrode disposed in contact with the nanocrystal film, not in contact with the first electrode

Solar cells based on quantum dot or colloidal nanocrystal films

Photoreflectance spectra have been used to characterize miniband formation in GaAs/ Alx Ga1−x As superlattices with wide wells (275–255 A) and withb arriers as thin as 17 A. Thirty‐two optical transitions are resolved in the photoreflectance spectra of the 17 A barrier sample. These experimental transitions match all those theoretically predicted from the selection rule Δn=0, including Γ‐ and Π‐type transitions arising from miniband dispersion; these results imply sample perfection. A sample with a 40 A barrier exhibits forbidden transitions with Δn≠0; these additional transitions, together with the narrow width of the minibands for 40 A barriers, create difficulty in resolving the miniband structure.

Miniband dispersion in GaAs/AlxGa1−xAs superlattices with wide wells and very thin barriers

A new type of photovoltaic cell is described. It is a photoelectrochemical device that is based on the dye sensitization of thin (10–30 μm) films of TiO2 nanoparticles in contact with a non-aqueous liquid electrolyte. The cell is very simple to fabricate and, in principle, its color can be tuned through the visible spectrum, ranging from being completely transparent to black by changing the absorption characteristics of the dye; the photovoltage of the cell is not determined by the threshold energy for light absorption (bandgap) as in conventional photovoltaic cells based on solid-state semiconductors. The highest present efficiency of the dye-sensitized photochemical solar cell is about 11%. The cell has the potential to be a low-cost photovoltaic option. Unique applications include photovoltaic power windows and photoelectrochromic windows.

Photochemical solar cells based on dye-sensitization of nanocrystalline TiO2

The optical and electron paramagnetic resonance (EPR) properties of InP nanocrystals, in which metallic gold or indium is present as an incorporated part of the nanocrystals, have been studied. A study of Au/InP quantum rods supports different carrier localization regimes compared to metal-free quantum rods, including the charge-separated state for which the electron and hole are located in different parts of the heterostructure. They also show that elongated semiconductors that grow on metallic catalysts have electronic properties that are different from those of pure semiconductor nanocrystals of the same shape. We have also developed a simple method for growing melted indium particles on the surface of colloidal spherical InP nanocrystals, and in these In/InP nanocrystals the emission is completely quenched while the absorption spectrum moves to red due to the strong mixing of the semiconductor and metal electronic states.

Arthur J. Nozik

Papers

Quantization effects in the photocurrent spectroscopy of superlattice electrodes

Solar cells based on quantum dot or colloidal nanocrystal films

Miniband dispersion in GaAs/AlxGa1−xAs superlattices with wide wells and very thin barriers

Photochemical solar cells based on dye-sensitization of nanocrystalline TiO2

Charge separation in heterostructures of InP nanocrystals with metal particles.