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

Wetting phenomena are ubiquitous in nature and technology. A solid substrate exposed to the environment is almost invariably covered by a layer of fluid material. In this review, the surface forces that lead to wetting are considered, and the equilibrium surface coverage of a substrate in contact with a drop of liquid. Depending on the nature of the surface forces involved, different scenarios for wetting phase transitions are possible; recent progress allows us to relate the critical exponents directly to the nature of the surface forces which lead to the different wetting scenarios. Thermal fluctuation effects, which can be greatly enhanced for wetting of geometrically or chemically structured substrates, and are much stronger in colloidal suspensions, modify the adsorption singularities. Macroscopic descriptions and microscopic theories have been developed to understand and predict wetting behavior relevant to microfluidics and nanofluidics applications. Then the dynamics of wetting is examined. A drop, placed on a substrate which it wets, spreads out to form a film. Conversely, a nonwetted substrate previously covered by a film dewets upon an appropriate change of system parameters. The hydrodynamics of both wetting and dewetting is influenced by the presence of the three-phase contact line separating "wet" regions from those that are either dry or covered by a microscopic film only. Recent theoretical, experimental, and numerical progress in the description of moving contact line dynamics are reviewed, and its relation to the thermodynamics of wetting is explored. In addition, recent progress on rough surfaces is surveyed. The anchoring of contact lines and contact angle hysteresis are explored resulting from surface inhomogeneities. Further, new ways to mold wetting characteristics according to technological constraints are discussed, for example, the use of patterned surfaces, surfactants, or complex fluids.

/pdf/wetting-and-spreading-56ditqbfmj.pdf

Wetting and Spreading

Annual review of condensed matter physics

Journal of Statistical Mechanics: theory and experiment

Tables of integrals

Magnetization and ${}^{63}\mathrm{Cu}$ nuclear magnetic resonance-nuclear quadrupole resonance relaxation measurements are used to study the superconducting fluctuations in ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6+x}$ (YBCO) oriented powders. In optimally doped YBCO the fluctuating negative magnetization ${M}_{\mathrm{fl}}(H,T)$ is rather well described by an anisotropic Ginzburg-Landau (GL) functional and the curves ${M}_{\mathrm{fl}}/\sqrt{H}$ cross at ${T}_{c}.$ In underdoped YBCO, instead, over a wide temperature range an anomalous diamagnetism is observed, stronger than in the optimally doped compound by about an order of magnitude. The field and temperature dependence of ${M}_{\mathrm{fl}}$ cannot be described either by an anisotropic GL functional or on the basis of scaling arguments. The anomalous diamagnetism is more pronounced in samples with a defined order in the Cu(1)O chains. The ${}^{63}\mathrm{Cu}(2)$ relaxation rate shows little, if any, field dependence in the vicinity of the transition temperature ${T}_{c}(H=0).$ It is argued how the results in the underdoped compounds can be accounted for by the presence of charge inhomogeneities, favored by chains ordering.

Superconducting fluctuations and anomalous diamagnetism in underdoped YBa 2 Cu 3 O 6 + x from magnetization and 63 Cu NMR-NQR relaxation measurements

We reveal a phase transition with decreasing viscosity ν at ν=νc>0 in one-dimensional decaying Burgers turbulence with a power-law–correlated random profile of Gaussian-distributed initial velocities . The low-viscosity phase exhibits non-Gaussian one-point probability density of velocities, continuously dependent on ν, reflecting a spontaneous one-step replica symmetry breaking (RSB) in the associated statistical-mechanics problem. We obtain the low orders cumulants analytically. Our results, which are checked numerically, are based on combining insights in the mechanism of the freezing transition in random logarithmic potentials with an extension of duality relations discovered recently in the random matrix theory. They are essentially non–mean-field in nature as also demonstrated by the shock size distribution computed numerically and different from the short-range–correlated Kida model. We also provide some insights for the finite-viscosity behaviour of velocities in the latter model.

/pdf/freezing-transition-in-decaying-burgers-turbulence-and-279us4eipz.pdf

Freezing transition in decaying Burgers turbulence and random matrix dualities

We reveal a phase transition with decreasing viscosity $\nu$ at \nu=\nu_c>0 in one-dimensional decaying Burgers turbulence with a power-law correlated random profile of Gaussian-distributed initial velocities \sim|x-x'|^{-2}. The low-viscosity phase exhibits non-Gaussian one-point probability density of velocities, continuously dependent on \nu, reflecting a spontaneous one step replica symmetry breaking (RSB) in the associated statistical mechanics problem. We obtain the low orders cumulants analytically. Our results, which are checked numerically, are based on combining insights in the mechanism of the freezing transition in random logarithmic potentials with an extension of duality relations discovered recently in Random Matrix Theory. They are essentially non mean-field in nature as also demonstrated by the shock size distribution computed numerically and different from the short range correlated Kida model, itself well described by a mean field one step RSB ansatz. We also provide some insights for the finite viscosity behaviour of velocities in the latter model.

Freezing Transition in Decaying Burgers Turbulence and Random Matrix Dualities

We study the random acceleration model, which is perhaps one of the simplest, yet nontrivial, non-Markov stochastic processes, and is key to many applications. For this non-Markov process, we present exact analytical results for the probability density p(tm|T) of the time tm at which the process reaches its maximum, within a fixed time interval [0, T]. We study two different boundary conditions, which correspond to the process representing respectively (i) the integral of a Brownian bridge and (ii) the integral of a free Brownian motion. Our analytical results are also verified by numerical simulations.

/pdf/time-at-which-the-maximum-of-a-random-acceleration-process-189bkhxfu2.pdf

Alberto Rosso

Papers

Superconducting fluctuations and anomalous diamagnetism in underdoped YBa 2 Cu 3 O 6 + x from magnetization and 63 Cu NMR-NQR relaxation measurements

Freezing transition in decaying Burgers turbulence and random matrix dualities

Freezing Transition in Decaying Burgers Turbulence and Random Matrix Dualities

Time at which the maximum of a random acceleration process is reached

Statistics of the critical depinning force of elastic systems in random media