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

BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

“Bioinformatics” 특집을 내면서

5.1. Nanoalloys of Group 11 (Cu, Ag, Au) 865 5.1.1. Cu−Ag 866 5.1.2. Cu−Au 867 5.1.3. Ag−Au 870 5.1.4. Cu−Ag−Au 872 5.2. Nanoalloys of Group 10 (Ni, Pd, Pt) 872 5.2.1. Ni−Pd 872 * To whom correspondence should be addressed. Phone: +39010 3536214. Fax:+39010 311066. E-mail: ferrando@fisica.unige.it. † Universita di Genova. ‡ Argonne National Laboratory. § University of Birmingham. | As of October 1, 2007, Chemical Sciences and Engineering Division. Volume 108, Number 3

Nanoalloys: From Theory to Applications of Alloy Clusters and Nanoparticles

We attempt a classification of different colloidal gels based on colloid‐ colloid interactions. We discriminate primarily between non-equilibrium and equilibrium routes to gelation, the former case being slaved to thermodynamic phase separation while the latter is individuated in the framework of competing interactions and of patchy colloids. Emphasis is put on recent numerical simulations of colloidal gelation and their connection to experiments. Finally, we underline typical signatures of different gel types, to be looked at, in more detail, in experiments. (Some figures in this article are in colour only in the electronic version)

https://iopscience.iop.org/article/10.1088/0953-8984/19/32/323101/pdf

Colloidal gels: equilibrium and non-equilibrium routes

Gold is an element whose unique properties are strongly influenced by relativistic effects. A large body of appropriate calculations now exists and its main conclusions are summarized in this critical review. The present paper completes the recent reviews by Pyykko (2004, 2005) (529 references).

Theoretical chemistry of gold. III

Extends the self-consistent energy-independent model pseudopotential theory, developed previously for the binary allows of simple metals, to the calculation of the interionic pair potentials in the K-Rb, Na-K, Na-Cs, Li-Na, Li-Mg, Li-In and Li-Tl liquid alloys for a number of different concentrations. Then the authors determine, for these alloys, the hard-sphere diameters from the calculated interionic pair potentials for use in the determination of the partial structure factors in the Percus-Yevick approximation. Finally, the partial structure factors thus obtained are applied to calculate the electrical resistivities. It is found from the comparison of the calculated electrical resistivities with experiment that (a) the values proposed in this work for the hard-sphere diameters are reasonable and (b) the concentration dependence of the electrical resistivity in the liquid binary alloy, in which the electronegativity difference between two components is significant, is primarily dependent upon the partial localisation of the valence electrons on the electronegative ions in the alloy.

https://iopscience.iop.org/article/10.1088/0305-4608/10/12/012/pdf

Structure and electrical resistivities of liquid binary alloys

A fine Au powder, with a mean particle diameter of 4 nm, has been successfully fabricated. The crystalline structure of the 4 nm Au nanoparticles remains in fcc symmetry. No structural changes were found between 15 and 450 K. A crossover from a positive thermal expansion at low temperatures to a negative thermal expansion at high temperatures was observed in the fcc cell parameter at about 125 K. Anomalies associated with the crossover were also observed in the magnetic response and the heat capacity measurements. The observations can be reasonably well interpreted by accounting for the effects of the valence electron potential on the equilibrium lattice separations, with a weakly temperature dependent level spacing.

Thermal contraction of au nanoparticles.

We report an optimization algorithm for studying bimetallic nanoclusters. The algorithm combines two state-of-the-art methods, the genetic algorithm and the basin hopping approach, widely employed in the literature for predicting structures of pure metallic and nonmetallic clusters. To critically test the present algorithm and its use in determining the lowest-energy structures of bimetallic nanoclusters, we apply it to study the bimetallic clusters CunAu38−n (0⩽n⩽38). It is predicted that the Au atoms, being larger in size than the Cu atoms, prefer to occupy surface sites showing thus the segregating behavior. As the atom fraction of Cu increases, the bimetallic cluster CunAu38−n, as a whole, first takes on an amorphous structure and is followed by dramatic changes in structure with the Cu atoms revealing hexagonal, then assuming pentagonal, and finally shifting to octahedral symmetry in the Cu-rich range.

Structures of bimetallic clusters

We present detailed numerical results on the ground state structures of metallic clusters. The Gupta-type many-body potential is used to account for the interactions between atoms in the cluster. Both the genetic algorithm technique and the basin hopping method have been applied to search for the global energy minima of clusters. The excellent agreement found in both schemes for the global energy minima gives credence to the optimized energy values obtained. For four monovalent and one polyvalent metals studied in this work and within the accuracy of the energies presented here, we find that the global energy minima predicted by the basin hopping method are the same as those values obtained by the genetic algorithm. Our calculations for the ground state energies of alkali metallic clusters show regularities in the energy differences, and the cluster growth pattern manifested by this same group of clusters is generally icosahedral, which is quite different from the close-packed and decahedral preferentially exhibited by the tetravalent lead clusters. Considering the inherent disparities in the electronic properties and the bulk structures in these metals (body-centered cubic for alkali metals and face-centered cubic for the lead metal), it is not unreasonable to conjecture that the valence electrons do play a subtle role in the conformation of metallic clusters.

Structures of metallic clusters: Mono- and polyvalent metals

The authors first propose an approach for treating a correction from the higher-order perturbative terms to the usual low-order pseudopotential perturbation calculation for the one-valence-electron states in a disordered metal. Then, the previously used energy-independent non-local model pseudopotential (EINMP) with this correction is applied along with the original EINMP to the variational thermodynamic calculation in the framework of a hard-sphere reference system for the alkalis in the liquid phase and for the K-Rb, Na-K and Na-Cs liquid alloys. The results obtained for (i) the hard-sphere diameter, sigma , (ii) the isothermal compressibility, chi T, and (iii) the excess entropy, Sexc, are carefully examined and discussed. It appears that in going from the pure alkalis to their binary alloys, (i) the change in sigma follows closely the concept of valence-electron charge transfer, introduced previously to interpret the corresponding concentration dependence of the electrical resistivities and (ii) the deviations of chi T and Sexc from ideality for the Na-K and Na-Cs alloys are largely due to the valence-electron charge transfer, which affects sigma in Sexc and also affects the contribution from the volume dependence of the screening to chi T.

S. K. Lai

Papers

Structure and electrical resistivities of liquid binary alloys

Thermal contraction of au nanoparticles.

Structures of bimetallic clusters

Structures of metallic clusters: Mono- and polyvalent metals

Variational thermodynamic calculation for simple liquid metals and alkali alloys