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

J. Appl. Cryst.の発刊に際して

Peptides or proteins convert under some conditions from their soluble forms into highly ordered fibrillar aggregates. Such transitions can give rise to pathological conditions ranging from neurodegenerative disorders to systemic amyloidoses. In this review, we identify the diseases known to be associated with formation of fibrillar aggregates and the specific peptides and proteins involved in each case. We describe, in addition, that living organisms can take advantage of the inherent ability of proteins to form such structures to generate novel and diverse biological functions. We review recent advances toward the elucidation of the structures of amyloid fibrils and the mechanisms of their formation at a molecular level. Finally, we discuss the relative importance of the common main-chain and side-chain interactions in determining the propensities of proteins to aggregate and describe some of the evidence that the oligomeric fibril precursors are the primary origins of pathological behavior.

/pdf/protein-misfolding-functional-amyloid-and-human-disease-2w386pwb7k.pdf

Protein Misfolding, Functional Amyloid, and Human Disease

We review the dynamical mean-field theory of strongly correlated electron systems which is based on a mapping of lattice models onto quantum impurity models subject to a self-consistency condition. This mapping is exact for models of correlated electrons in the limit of large lattice coordination (or infinite spatial dimensions). It extends the standard mean-field construction from classical statistical mechanics to quantum problems. We discuss the physical ideas underlying this theory and its mathematical derivation. Various analytic and numerical techniques that have been developed recently in order to analyze and solve the dynamical mean-field equations are reviewed and compared to each other. The method can be used for the determination of phase diagrams (by comparing the stability of various types of long-range order), and the calculation of thermodynamic properties, one-particle Green's functions, and response functions. We review in detail the recent progress in understanding the Hubbard model and the Mott metal-insulator transition within this approach, including some comparison to experiments on three-dimensional transition-metal oxides. We present an overview of the rapidly developing field of applications of this method to other systems. The present limitations of the approach, and possible extensions of the formalism are finally discussed. Computer programs for the numerical implementation of this method are also provided with this article.

Dynamical mean-field theory of strongly correlated fermion systems and the limit of infinite dimensions

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

Electromagnetic radiation is a universal probe for studying the chemical and structural properties of matter. Since the 1960's, new sources providing a unique form of such radiation, called synchro...

SYNCHROTRON RADIATION Special Report

We study a percolating network of highly hysteretic Josephson junctions in which each junction is modelled as a piecewise-Ohmic hysteretic device. At the percolation threshold, the average voltage drop across a network on a large L × L grid is assumed to fall to zero as V ∼ ( I − I c ( L )) η as the applied current is reduced to the critical current I c ( L ). Our finite-size Monte Carlo study gives the value η = 2.0±0.1. This value is remarkably close to the result η =2 obtained by a scaling analysis of a continuum version of the model.

Finite-voltage behavior of highly-disordered granular superconductors

Structural Studies of Proteins and Nucleic Acids in Solution Using Small Angle X-Ray Scattering (SAXS)

Photoemission involving an intermediate core-hole \ensuremath{\rightarrow} bound-valence transition shows a strong resonance enhancement as the photon energy is tuned through the intermediate-state transition energy. We have studied the effects of electronic relaxation in both intermediate and final states on the line shapes of this resonant photoemission spectra. We consider two simple models of the relaxation process---discrete plasmon-type relaxation and continuous electron-hole-pair relaxation models---and calculate the photoemission cross section as a function of both final photoelectron energy $\ensuremath{\epsilon}$ and incident photon energy $\ensuremath{\omega}$. In the case of discrete plasmon-type relaxation, $\ensuremath{\omega}$ dependence of the plasmon satellite strength shows qualitative differences depending on the plasmon coupling constants in the intermediate and final states. If a damping or dispersion of plasmons is included, there appears a new peak at fixed electron kinetic energy in addition to the usual plasmon satellite peak, which we call a "fluorescent electron emission peak," as a result of intermediate-state relaxation. In the continuous electron-hole-pair case, the Doniach-Sunjic asymmetry parameter depends on the incident photon energy $\ensuremath{\omega}$. This $\ensuremath{\omega}$ dependence arises because the system has a longer time to adjust towards the fully relaxed intermediate state when the system is on resonance, while the final-state relaxation determines the line shape off resonance.

Line shapes in resonant photoemission spectra

We propose that the pseudogap state observed in the transition metal oxides can be explained by a three-dimensional flux state, which exhibits spontaneously generated currents in its ground state due to electron-electron correlations. We compare the energy of the flux state to other classes of mean field states, and find that it is stabilized over a wide range of t and $\ensuremath{\delta}.$ The signature of the state will be peaks in the neutron diffraction spectra, the location and intensity of which are presented. The dependence of the pseudogap in the optical conductivity is calculated based on the parameters in the model.

Sebastian Doniach

Papers

SYNCHROTRON RADIATION Special Report

Finite-voltage behavior of highly-disordered granular superconductors

Structural Studies of Proteins and Nucleic Acids in Solution Using Small Angle X-Ray Scattering (SAXS)

Line shapes in resonant photoemission spectra

Three-dimensional flux states as a model for the pseudogap phase of transition metal oxides