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

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

The ff94 force field that is commonly associated with the Amber simulation package is one of the most widely used parameter sets for biomolecular simulation. After a decade of extensive use and testing, limitations in this force field, such as over-stabilization of alpha-helices, were reported by us and other researchers. This led to a number of attempts to improve these parameters, resulting in a variety of "Amber" force fields and significant difficulty in determining which should be used for a particular application. We show that several of these continue to suffer from inadequate balance between different secondary structure elements. In addition, the approach used in most of these studies neglected to account for the existence in Amber of two sets of backbone phi/psi dihedral terms. This led to parameter sets that provide unreasonable conformational preferences for glycine. We report here an effort to improve the phi/psi dihedral terms in the ff99 energy function. Dihedral term parameters are based on fitting the energies of multiple conformations of glycine and alanine tetrapeptides from high level ab initio quantum mechanical calculations. The new parameters for backbone dihedrals replace those in the existing ff99 force field. This parameter set, which we denote ff99SB, achieves a better balance of secondary structure elements as judged by improved distribution of backbone dihedrals for glycine and alanine with respect to PDB survey data. It also accomplishes improved agreement with published experimental data for conformational preferences of short alanine peptides and better accord with experimental NMR relaxation data of test protein systems.

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Comparison of multiple Amber force fields and development of improved protein backbone parameters.

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?

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

A method is presented whereby the WKB expression for tunneling frequencies permits correlation of these frequencies for members of homologous series of molecules The necessary data required are the tunneling rate for one member of the series, and structural parameters and vibrational frequencies for all members of interest The method is applied to ND3, NF3, PH3, and AsH3, using NH3 as the molecule whose frequency is known The method also is used to support the hypothesis that pseudorotation occurs in the trigonal bipyramids PF5 and PCl5

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Correlation of Rates of Intramolecular Tunneling Processes, with Application to Some Group V Compounds

1. The Wave Mechanics of Diatomic Molecules 2. Summary Elements of Algebraic Theory 3. Mechanics of Molecules 4. Three-Body Algebraic Theory 5. Four-Body Algebraic Theory 6. Many-Body Algebraic Theory 7. Classical Limit and Coordinate Representation 8. Prologue to the Future Appendices: Properties of Lie Algebras Coupling of Algebras Hamiltonian Parameters

Algebraic theory of molecules

Theory of Elementary Atomic and Molecular Processes in Gases

Until the 19th century, technology was essentially the domain of skilled artisans and constructors who relied on practical experience to design and build their machines. One of the first efforts to use physical theory to study the functioning of machines was undertaken by the French engineer Sadi Carnot. Motivated by the concern of the French about the superiority of British steam engines, he undertook a systematic study of the physical processes governing steam engines, resulting in his remarkable paper Reflexions sur la puissance motrice du feu (On the Motive Power of Heat) published in 1826. Among the earliest successes of this new science, thermodynamics, was the formulation of criteria describing how well real processes perform in comparison with an ideal model. Carnot showed that any engine, using heat from a hot reservoir at temperature Th to do work, has to transfer some heat to a reservoir at lower temperature T1, and that no engine could convert into work more of the heat taken in at Th than the...

Thermodynamics in finite time

Simulations by molecular dynamics of 13‐particle clusters of argon display distinct nonrigid, liquid‐like and near‐rigid, solid‐like ‘‘phases.’’ The simulations, conducted at constant total energy, display a low‐energy region in which only the solid‐like form appears, a high‐energy region in which only the liquid‐like form appears, and an intermediate band of energy—a ‘‘coexistence region’’— in which clusters exhibit both forms. The intervals of time spent in each phase in the two‐form coexistence region are long compared with the intervals required to establish equilibrium‐like properties distinctive of each form, such as mean square displacement and power spectrum, so that well‐defined phases can be said to exist. The fraction of time spent in each phase is a function of the energy. When a long simulation is separated into regions of solid‐like and liquid‐like behavior, the curve of the derived caloric equation of state is double valued in the two‐phase range of energy, forming two well‐defined, smooth branches. When, instead, the caloric curve is constructed from averages over all of a long run, its form is smooth and monotonic showing no trace of the ‘‘loop’’ that had been reported for earlier treatments with much shorter molecular dynamics runs, and which we could also reproduce with short runs.

R. Stephen Berry

Papers

Correlation of Rates of Intramolecular Tunneling Processes, with Application to Some Group V Compounds

Algebraic theory of molecules

Theory of Elementary Atomic and Molecular Processes in Gases

Thermodynamics in finite time

Solid–liquid phase changes in simulated isoenergetic Ar13