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

To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

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Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

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

Quantification of global forest change has been lacking despite the recognized importance of forest ecosystem services. In this study, Earth observation satellite data were used to map global forest loss (2.3 million square kilometers) and gain (0.8 million square kilometers) from 2000 to 2012 at a spatial resolution of 30 meters. The tropics were the only climate domain to exhibit a trend, with forest loss increasing by 2101 square kilometers per year. Brazil's well-documented reduction in deforestation was offset by increasing forest loss in Indonesia, Malaysia, Paraguay, Bolivia, Zambia, Angola, and elsewhere. Intensive forestry practiced within subtropical forests resulted in the highest rates of forest change globally. Boreal forest loss due largely to fire and forestry was second to that in the tropics in absolute and proportional terms. These results depict a globally consistent and locally relevant record of forest change.

High-Resolution Global Maps of 21st-Century Forest Cover Change

PHREEQC version 2 is a computer program written in the C programming language that is designed to perform a wide variety of low-temperature aqueous geochemical calculations. PHREEQC is based on an ion-association aqueous model and has capabilities for (1) speciation and saturation-index calculations; (2) batch-reaction and onedimensional (1D) transport calculations involving reversible reactions, which include aqueous, mineral, gas, solidsolution, surface-complexation, and ion-exchange equilibria, and irreversible reactions, which include specified mole transfers of reactants, kinetically controlled reactions, mixing of solutions, and temperature changes; and (3) inverse modeling, which finds sets of mineral and gas mole transfers that account for differences in composition between waters, within specified compositional uncertainty limits. New features in PHREEQC version 2 relative to version 1 include capabilities to simulate dispersion (or diffusion) and stagnant zones in 1D-transport calculations, to model kinetic reactions with user-defined rate expressions, to model the formation or dissolution of ideal, multicomponent or nonideal, binary solid solutions, to model fixed-volume gas phases in addition to fixed-pressure gas phases, to allow the number of surface or exchange sites to vary with the dissolution or precipitation of minerals or kinetic reactants, to include isotope mole balances in inverse modeling calculations, to automatically use multiple sets of convergence parameters, to print user-defined quantities to the primary output file and (or) to a file suitable for importation into a spreadsheet, and to define solution compositions in a format more compatible with spreadsheet programs. This report presents the equations that are the basis for chemical equilibrium, kinetic, transport, and inverse modeling calculations in PHREEQC; describes the input for the program; and presents examples that demonstrate most of the program's capabilities.

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User's guide to PHREEQC (Version 2)-a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations

The marginal but selective encapsulation of ions by growing ice induces transient polarizations. Electroneutrality is ultimately restored via H + /OH − interfacial migration producing fluid phases of altered acidity. The media in which solutes become confined upon freezing are, therefore, not only more concentrated but have different acidities than the precursor solutions. This largely unrecognized phenomenon should affect reaction rates and equilibria in frozen aqueous systems. We report, for the first time, measurements of the acidity of extensively frozen dilute solutions of various electrolytes based on the temperature dependence of the 19 F chemical shifts of the 3-fluorobenzoic acid in situ probe. We find that acidity significantly increases or decreases upon freezing depending on the type of ions involved. In particular, NaCl, NaNO2 and KNO3 solutions become more basic, while NH4OH or Na2SO4 solutions become more acidic, upon freezing. The environmental implications of these results are briefly analyzed.

19 F NMR Probing the Acidity of Frozen Electrolyte Solutions

Kinetics, Thermodynamics,and Mechanism of the Formation of Benzaldehyde-S(IV) Adducts.

Aspects of the invention include a porous and water-permeable electrode for electrocatalysis comprising: a porous and water-permeable reactive electrochemical membrane ("REM") comprising: a porous and water-permeable support membrane; wherein the support membrane comprises a titanium metal; and an electrocatalytic coating on at least a portion of the metal support membrane, the electrocatalytic coating being a tin oxide bilayer comprising: a first layer adjacent to and directly contacting the metal support membrane; wherein the first layer comprises tin oxide doped with antimony; and a second layer adjacent to and directly contacting the first layer; wherein the second layer forms a surface of the REM such that the second layer is in direct contact with an aqueous solution when the REM is in contact with the aqueous solution; wherein the second layer comprises tin oxide doped with antimony and nickel or cerium. Preferably, the support membrane is formed of a titanium metal.

Reactive electrochemical membrane for wastewater treatment

Herein we report a K1–xNixNbO3 composite undergoing a phase transition from orthorhombic to rhombohedral, resulting in a Ni particle and a short Nb–Oδ- on the surface caused by a structural distortion. The Ni particles are dispersed on the overall surface of the structure, and the short bonded Nb–Oδ- sticks out to the structure interstices on the surface. The properties of the structure and surface of K1–xNixNbO3 are defined by spectroscopic analysis of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman, nuclear magnetic resonance (1H NMR), and X-ray photoelectron spectroscopy (XPS). This unique surface property enables the formation of two hybrid composites that deposit CdS on either site of the Ni/Ni–H particle or short Nb–Oδ-, resulting in a different interface between CdS and K1–xNixNbO3. The one that deposits CdS on the Ni/Ni–H particles is denoted as SCdS/K1–xNixNbO3, and the other that deposits CdS on the short Nb–Oδ- is denoted as CdS/K0.9Ni0.1NbO3. SCdS/K1–xNixNbO3 exhibits a delayed kinetics for CdS photoinduced electrons compared to that of CdS/K1–xNixNbO3 as decayed fluorescence at ca. 311 ps, while indicating ca. 238 ps for CdS/K1–xNixNbO3. As a result, SCdS/K1–xNixNbO3 exhibits a superior photocatalytic activity for H2 production of ca. 3.1 mmol g–1 h–1 compared to CdS/K1–xNixNbO3 with ca. 2.7 mmol g–1 h–1. 

Application of a Functionalized K1–xNixNbO3 Structure: Enhancing the Photocatalytic Activity of a CdS/K1–xNixNbO3 Composite

Common Dwarf Mongoose Helogale parvula is a small, social mongoose (Herpestidae) widely distributed from the Horn of Africa to the north-eastern parts of South Africa’s KwaZulu– Natal province (Kingdon 1977, Creel 2013). Creel (2013) described it as most common in open woodlands, thickets and wooded savannas, particularly where there are termitaria, rock outcroppings or crevices, or hollow logs for use as dens. Waser et al. (1995) suggested that the most important determinant of Common Dwarf Mongoose habitat preference is the density of suitable dens, with active or quiescent termite mounds (especially those of Macrotermes) being particularly favoured. While it is often observed clambering on termitaria, rocks or logs or branches of fallen trees, it is not commonly considered a climber and tree denning is rarely recorded. Indeed, Rautenbach (1982: 140) noted that “Helogale parvula

Michael R. Hoffmann

Papers

19 F NMR Probing the Acidity of Frozen Electrolyte Solutions

Kinetics, Thermodynamics,and Mechanism of the Formation of Benzaldehyde-S(IV) Adducts.

Reactive electrochemical membrane for wastewater treatment

Application of a Functionalized K1–xNixNbO3 Structure: Enhancing the Photocatalytic Activity of a CdS/K1–xNixNbO3 Composite

Tree climbing and denning by Common Dwarf Mongoose Helogale parvula