다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

The calculation of rate coefficients is a discipline of nonlinear science of importance to much of physics, chemistry, engineering, and biology. Fifty years after Kramers' seminal paper on thermally activated barrier crossing, the authors report, extend, and interpret much of our current understanding relating to theories of noise-activated escape, for which many of the notable contributions are originating from the communities both of physics and of physical chemistry. Theoretical as well as numerical approaches are discussed for single- and many-dimensional metastable systems (including fields) in gases and condensed phases. The role of many-dimensional transition-state theory is contrasted with Kramers' reaction-rate theory for moderate-to-strong friction; the authors emphasize the physical situation and the close connection between unimolecular rate theory and Kramers' work for weakly damped systems. The rate theory accounting for memory friction is presented, together with a unifying theoretical approach which covers the whole regime of weak-to-moderate-to-strong friction on the same basis (turnover theory). The peculiarities of noise-activated escape in a variety of physically different metastable potential configurations is elucidated in terms of the mean-first-passage-time technique. Moreover, the role and the complexity of escape in driven systems exhibiting possibly multiple, metastable stationary nonequilibrium states is identified. At lower temperatures, quantum tunneling effects start to dominate the rate mechanism. The early quantum approaches as well as the latest quantum versions of Kramers' theory are discussed, thereby providing a description of dissipative escape events at all temperatures. In addition, an attempt is made to discuss prominent experimental work as it relates to Kramers' reaction-rate theory and to indicate the most important areas for future research in theory and experiment.

Reaction-rate theory: fifty years after Kramers

N G van Kampen 1981 Amsterdam: North-Holland xiv + 419 pp price Dfl 180 This is a book which, at a lower price, could be expected to become an essential part of the library of every physical scientist concerned with problems involving fluctuations and stochastic processes, as well as those who just enjoy a beautifully written book. It provides an extensive graduate-level introduction which is clear, cautious, interesting and readable.

https://iopscience.iop.org/article/10.1088/0031-9112/34/4/040/pdf

Stochastic Processes in Physics and Chemistry

1980 Preface * 1999 Preface * 1999 Acknowledgements * Introduction * 1 Circular Logic * 2 Phase Singularities (Screwy Results of Circular Logic) * 3 The Rules of the Ring * 4 Ring Populations * 5 Getting Off the Ring * 6 Attracting Cycles and Isochrons * 7 Measuring the Trajectories of a Circadian Clock * 8 Populations of Attractor Cycle Oscillators * 9 Excitable Kinetics and Excitable Media * 10 The Varieties of Phaseless Experience: In Which the Geometrical Orderliness of Rhythmic Organization Breaks Down in Diverse Ways * 11 The Firefly Machine 12 Energy Metabolism in Cells * 13 The Malonic Acid Reagent ('Sodium Geometrate') * 14 Electrical Rhythmicity and Excitability in Cell Membranes * 15 The Aggregation of Slime Mold Amoebae * 16 Numerical Organizing Centers * 17 Electrical Singular Filaments in the Heart Wall * 18 Pattern Formation in the Fungi * 19 Circadian Rhythms in General * 20 The Circadian Clocks of Insect Eclosion * 21 The Flower of Kalanchoe * 22 The Cell Mitotic Cycle * 23 The Female Cycle * References * Index of Names * Index of Subjects

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/596B270197FE27DE5FABB598B6210622/S0025557200150892a.pdf/div-class-title-span-class-italic-the-geometry-of-biological-time-span-by-a-t-winfree-pp-544-dm68-corrected-second-printing-1990-isbn-3-540-52528-9-springer-div.pdf

The geometry of biological time , by A. T. Winfree. Pp 544. DM68. Corrected Second Printing 1990. ISBN 3-540-52528-9 (Springer)

Activated processes at surfaces such as desorption or sublimation may exhibit a thermal anomaly at the Curie point of a magnetic substrate. We propose to measure this anomaly with an applied magnetic field H, and we predict a decrease in the reaction rate proportional to H" with x(T) T, ) =2, x(T & T, ) =1, and x(T=T, ) =2/6~, where 6~=1.9 is an exponent for ordinary phase transitions. In the case of a surface transition, or if the substrate is a film with two-dimensional Ising behavior, the anomaly is significantly enhanced. PACS numbers: 68.35.Rh, 82.65.Yh In this Letter we examine the behavior of thermally activated surface processes in an applied magnetic field. In the vicinity of a continuous magnetic phase transition these processes may exhibit anomalies in their reaction rate, r(T), known as the Hedvall effect. ' The experimentally observed deviation from the Arrhenius law r(T) =k exp( — Q/ktt T) depends not only on the type of the processdesorption, sublimation, oxidation, or catalytic reaction — but also on the specific substrate-adsorbate combination and on features such as oxide-layer thickness or on details of the surface preparation. This variety complicates the theoretical understanding of the Hedvall effect considerably. An important contribution was made by Suhl and co-workers some years ago. ' Combining the Kramers approach" to activated processes with linear-response theory, these authors expressed the activation energy Q and the attempt frequency k in Eq. (1) in terms of those static and dynamic degrees of freedom in the substrate which are coupled to the spin of the adsorbed particles. This coupling leads to a temperature dependence in k(T) and Q(T) which reAects the critical behavior of the substrate and thus causes deviations from a straight line in the Arrhenius plot ln(r) vs (1/T) near T,. It has recently been shown' that the anomaly in k, as well as in Q, is significantly weaker than predicted in earlier work for two reasons. (1) The relevant critical behavior of the substrate is that of its surface. ' In the case of the so-called ordinary transitions where the surface orders simultaneously with the bulk, the critical near-surface effects are weaker than those in the bulk. Only the bulk behavior was taken into account in Ref. 14. (2) The critical slowing down in the substrate invalidates a naive use of the Kramers approach since a clearcut separation in the time scales is no longer possible. Memory effects lead to a renormalized attempt frequency k which involves a dynamic correlation function at nonzero frequencies. Its anomaly turns out to be reduced compared to that of the zero-frequency limit employed in previous work. ' ' Such a weak anomaly appears to be in qualitative agreement with experiments. However, the uncertainties in the available data inhibit a quantitative comparison with the theory. Furthermore, these measurements of the rate, with temperature as the only control parameter, do not provide enough information to allow for stringent tests of crucial model assumptions. Therefore, we suggest Hedvall experiments be performed with an applied magnetic field H. This field is an additional parameter which can be varied reversibly in a controlled fashion during a measurement on a particular sample. We predict a decrease in the rate with increasing field as

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Critical magnetic field dependence of thermally activated surface processes

The fluctuation theorem for entropy production is a remarkable symmetry of the distribution of produced entropy that holds universally in non-equilibrium steady states with Markovian dynamics. However, in systems with slow degrees of freedom that are hidden from the observer, it is not possible to infer the amount of produced entropy exactly. Previous work suggested that a relation similar to the fluctuation theorem may hold at least approximately for such systems if one considers an apparent entropy production. By extending the notion of apparent entropy production to discrete bipartite systems, we investigate which criteria have to be met for such a modified fluctuation theorem to hold in the large deviation limit. We use asymptotic approximations of the large deviation function to show that the probabilities of extreme events of apparent entropy production always obey a modified fluctuation theorem and, moreover, that it is possible to infer otherwise hidden properties. For the paradigmatic case of two coupled colloidal particles on rings the rate function of the apparent entropy production is calculated to illustrate this asymptotic behavior and to show that the modified fluctuation theorem observed experimentally for short observation times does not persist in the long time limit.

Fluctuations of Apparent Entropy Production in Networks with Hidden Slow Degrees of Freedom

A general framework for the field-theoretic thermodynamic uncertainty relation was recently proposed and illustrated with the $$(1+1)$$
 dimensional Kardar–Parisi–Zhang equation. In the present paper, the analytical results obtained there in the weak coupling limit are tested via a direct numerical simulation of the KPZ equation with good agreement. The accuracy of the numerical results varies with the respective choice of discretization of the KPZ non-linearity. Whereas the numerical simulations strongly support the analytical predictions, an inherent limitation to the accuracy of the approximation to the total entropy production is found. In an analytical treatment of a generalized discretization of the KPZ non-linearity, the origin of this limitation is explained and shown to be an intrinsic property of the employed discretization scheme.

/pdf/numerical-study-of-the-thermodynamic-uncertainty-relation-1g1qen6hnk.pdf

Numerical Study of the Thermodynamic Uncertainty Relation for the KPZ-Equation

Shapes and shape transformations of vesicles are considered theoretically within the spontaneous curvature model for three cases. (i) For free vesicles, the whole phase diagram is presented which includes pear-shaped vesicles and a line of limit shapes related to budding. (ii) For toroidal vesicles, three branches of solutions with low energy are found. (iii) An extension of this model to the adhesion of vesicles is briefly discussed.

Shape transformations of free, toroidal and bound vesicles

We investigate the thermodynamic uncertainty relation for the $$(1+1)$$
 dimensional Kardar–Parisi–Zhang (KPZ) equation on a finite spatial interval. In particular, we extend the results for small coupling strengths obtained previously to large values of the coupling parameter. It will be shown that, due to the scaling behavior of the KPZ equation, the thermodynamic uncertainty relation (TUR) product displays two distinct regimes which are separated by a critical value of an effective coupling parameter. The asymptotic behavior below and above the critical threshold is explored analytically. For small coupling, we determine this product perturbatively including the fourth order; for strong coupling we employ a dynamical renormalization group approach. Whereas the TUR product approaches a value of 5 in the weak coupling limit, it asymptotically displays a linear increase with the coupling parameter for strong couplings. The analytical results are then compared to direct numerical simulations of the KPZ equation showing convincing agreement.

Udo Seifert

Papers

Critical magnetic field dependence of thermally activated surface processes

Fluctuations of Apparent Entropy Production in Networks with Hidden Slow Degrees of Freedom

Numerical Study of the Thermodynamic Uncertainty Relation for the KPZ-Equation

Shape transformations of free, toroidal and bound vesicles

The Two Scaling Regimes of the Thermodynamic Uncertainty Relation for the KPZ-Equation