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

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

/pdf/self-assembled-monolayers-of-thiolates-on-metals-as-a-form-1neb0hj3k4.pdf

Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

Highly luminescent semiconductor quantum dots (zinc sulfide-capped cadmium selenide) have been covalently coupled to biomolecules for use in ultrasensitive biological detection. In comparison with organic dyes such as rhodamine, this class of luminescent labels is 20 times as bright, 100 times as stable against photobleaching, and one-third as wide in spectral linewidth. These nanometer-sized conjugates are water-soluble and biocompatible. Quantum dots that were labeled with the protein transferrin underwent receptor-mediated endocytosis in cultured HeLa cells, and those dots that were labeled with immunomolecules recognized specific antibodies or antigens.

http://science.sciencemag.org/content/sci/281/5385/2016.full.pdf

Quantum Dot Bioconjugates for Ultrasensitive Nonisotopic Detection

In a communications system implementing Signaling System No. 7, the system comprising a link, a transmitter for transmitting digital data on the link, and a receiver; a communications method comprises: coupling to the link for receiving data; receiving data from the link; detecting an error condition of SS7 requiring the receiver circuit to operate in an octet counting mode; and initiating the counting of received octets, the counting beginning after detecting the error condition. The method can be implemented in a variety of ways, including without limitation, as a specially dedicated stand alone unit, as an adapter card in a computer system, or as a computer-readable medium such as a diskette or a digital transmission.

Counting octets and implementing the octet counting mode

Cation exchange is a versatile tool used to alter the composition of nanostructures and thus to design next-generation catalysts and photonic and electronic devices. However, chemical impurities inherited from the starting materials can degrade device performance. Here, we use a sequential cation-exchange process to convert PbSe into CdSe nanocrystal thin films and study their temperature-dependent electrical properties in the platform of the thin-film transistor. We show that residual Pb impurities have detrimental effects on the device turn-on, hysteresis, and electrical stability, and as the amount increases from 2% to 7%, the activation energy for carrier transport increases from 38(3) to 62(2) meV. Selection and surface functionalization of the transistor's gate oxide layer and low-temperature atomic-layer deposition encapsulation of the thin-film channel suppress these detrimental effects. By conversion of the nanocrystal thin films layer upon layer, impurities are driven away from the gate-oxide interface and mobilities improve from 3(1) to 32(3) cm2 V-1 s-1.

Impurities in Nanocrystal Thin-Film Transistors Fabricated by Cation Exchange.

Efficient photoluminescence of isotropic rare-earth oxychloride nanocrystals from a solvothermal route

Strongly coupled, epitaxially fused colloidal nanocrystal (NC) solids are promising solution-processable semiconductors to realize optoelectronic devices with high carrier mobilities. Here, we demonstrate sequential, solid-state cation exchange reactions to transform epitaxially connected PbSe NC thin films into Cu2Se nanostructured thin-film intermediates and then successfully to achieve zinc-blende, CdSe NC solids with wide epitaxial necking along {100} facets. Transient photoconductivity measurements probe carrier transport at nanometer length scales and show a photoconductance of 0.28(1) cm2 V-1 s-1, the highest among CdSe NC solids reported. Atomic-layer deposition of a thin Al2O3 layer infiltrates and protects the structure from fusing into a polycrystalline thin film during annealing and further improves the photoconductance to 1.71(5) cm2 V-1 s-1 and the diffusion length to 760 nm. We fabricate field-effect transistors to study carrier transport at micron length scales and realize high electron mobilities of 35(3) cm2 V-1 s-1 with on-off ratios of 106 after doping.

Enhanced Carrier Transport in Strongly Coupled, Epitaxially Fused CdSe Nanocrystal Solids

A first device comprising a first organic light emitting device (OLED) is described. The first OLED includes an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer includes a phosphorescent emissive dopant and a host material. The host material includes inorganic nanocrystals where (i) at least 50% of ligands bonded to said nanocrystals are compact ligands, (ii) an average interparticle distance between adjacent nanoparticles is ≦1 nm, or (iii) both. Also described are a method of making the emissive layer and a composition that includes the phosphorescent emissive dopant with the host materials that include the electronically-coupled inorganic nanocrystal host material.

Christopher B. Murray

Papers

Counting octets and implementing the octet counting mode

Impurities in Nanocrystal Thin-Film Transistors Fabricated by Cation Exchange.

Efficient photoluminescence of isotropic rare-earth oxychloride nanocrystals from a solvothermal route

Enhanced Carrier Transport in Strongly Coupled, Epitaxially Fused CdSe Nanocrystal Solids

Host for organic light emitting devices