The liquid-vapor interface of an ionic fluid

We investigate the liquid-vapor interface of the restricted primitive model (RPM) for an ionic fluid using a density-functional approximation based on correlation functions of the homogeneous fluid as obtained from the mean-spherical approximation (MSA). In the limit of a homogeneous fluid our approach yields the well-known MSA (energy) equation of state. The ionic interfacial density profiles, which for the RPM are identical for both species, have a shape similar to those of simple atomic fluids in that the decay towards the bulk values is more rapid on the vapor side than on the liquid side. This is the opposite asymmetry of the decay to that found in earlier calculations for the RPM based on a square-gradient theory. The width of the interface is, for a wide range of temperatures, approximately four times the second moment correlation length of the liquid phase. We discuss the magnitude and temperature dependence of the surface tension, and argue that for temperatures near the triple point the ratio of the dimensionless surface tension and critical temperature is much smaller for the RPM than for simple atomic fluids.Comment: 6 postscript figures, submitted to Phys. Rev.

Lattice theory of trapping reactions with mobile species

We present a stochastic lattice theory describing the kinetic behavior of trapping reactions $A + B \to B$, in which both the $A$ and $B$ particles perform an independent stochastic motion on a regular hypercubic lattice. Upon an encounter of an $A$ particle with any of the $B$ particles, $A$ is annihilated with a finite probability; finite reaction rate is taken into account by introducing a set of two-state random variables - "gates", imposed on each $B$ particle, such that an open (closed) gate corresponds to a reactive (passive) state. We evaluate here a formal expression describing the time evolution of the $A$ particle survival probability, which generalizes our previous results. We prove that for quite a general class of random motion of the species involved in the reaction process, for infinite or finite number of traps, and for any time $t$, the $A$ particle survival probability is always larger in case when $A$ stays immobile, than in situations when it moves.Comment: 12 pages, appearing in PR

Relationship between dynamical heterogeneities and stretched exponential relaxation

We identify the dynamical heterogeneities as an essential prerequisite for stretched exponential relaxation in dynamically frustrated systems. This heterogeneity takes the form of ordered domains of finite but diverging lifetime for particles in atomic or molecular systems, or spin states in magnetic materials. At the onset of the dynamical heterogeneity, the distribution of time intervals spent in such domains or traps becomes stretched exponential at long time. We rigorously show that once this is the case, the autocorrelation function of the renewal process formed by these time intervals is also stretched exponential at long time.Comment: 8 pages, 4 figures, submitted to PR

Universality of the thermodynamic Casimir effect

Recently a nonuniversal character of the leading spatial behavior of the thermodynamic Casimir force has been reported [X. S. Chen and V. Dohm, Phys. Rev. E {\bf 66}, 016102 (2002)]. We reconsider the arguments leading to this observation and show that there is no such leading nonuniversal term in systems with short-ranged interactions if one treats properly the effects generated by a sharp momentum cutoff in the Fourier transform of the interaction potential. We also conclude that lattice and continuum models then produce results in mutual agreement independent of the cutoff scheme, contrary to the aforementioned report. All results are consistent with the {\em universal} character of the Casimir force in systems with short-ranged interactions. The effects due to dispersion forces are discussed for systems with periodic or realistic boundary conditions. In contrast to systems with short-ranged interactions, for $L/\xi \gg 1$ one observes leading finite-size contributions governed by power laws in $L$ due to the subleading long-ranged character of the interaction, where $L$ is the finite system size and $\xi$ is the correlation length.Comment: 11 pages, revtex, to appear in Phys. Rev. E 68 (2003

A CsI(Tl) Scintillating Crystal Detector for the Studies of Low Energy Neutrino Interactions

Scintillating crystal detector may offer some potential advantages in the low-energy, low-background experiments. A 500 kg CsI(Tl) detector to be placed near the core of Nuclear Power Station II in Taiwan is being constructed for the studies of electron-neutrino scatterings and other keV-MeV range neutrino interactions. The motivations of this detector approach, the physics to be addressed, the basic experimental design, and the characteristic performance of prototype modules are described. The expected background channels and their experimental handles are discussed.Comment: 34 pages, 11 figures, submitted to Nucl. Instrum. Method

Active Brownian Particles. From Individual to Collective Stochastic Dynamics

We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

Characteristics and outcome of patients with low-/intermediate-risk acute promyelocytic leukemia treated with arsenic trioxide - an international collaborative study

The aim of this study was to characterize a large series of 154 patients with acute promyelocytic leukemia (APL; median age, 53 years; range, 18-90 years) and evaluate real-life outcome after up-front treatment with arsenic trioxide (ATO) and alltrans retinoic acid (ATRA). All patients were included in the prospective NAPOLEON registry (NCT02192619) between 2013 and 2019. APL was de novo in 91% (n=140) and therapy-related in 9% (n=14); 13% (n=20) were older than 70 years. At diagnosis bleeding/hemorrhage was present in 38% and thrombosis in 3%. Complete remission was achieved in 152 patients (99%), whereas two patients (1%) experienced induction death within 18 days after start of therapy. With a median follow-up of 1.99 years (95%-CI, 1.61-2.30 years) 1-year and 2-years overall survival (OS) rates were 97% (95%-CI, 94-100%) and 95% (95%-CI, 91-99%), respectively. Age above 70 years was associated with a significantly shorter OS (P<0.001) as compared to younger patients. So far no relapses were observed. Six patients (4%) died in CR after in median 0.95 years after diagnosis (range, 0.18-2.38 years). Our data confirm the efficiency and durability of ATO/ATRA in the primary management of adult low-/ intermediate-risk APL patients in the real life setting, irrespective of age

Wetting layers in electrolyte solutions

When a predominantly nonpolar mixture is in contact with a chemically ionizable substrate, thick wetting layers of a predominantly polar phase can form on the substrate. This paper considers the effects of added salt on such layers. In the limit of low salt concentrations, the equilibrium thickness reduces to a result previously derived by the author. In the limit of high salt concentrations, the thickness reduces to a Debye screening length times a known function of two dimensionless parameters.Lorsqu'un mélange de liquide non polaire et de liquide polaire est mis en contact avec un substrat chimiquement ionisable, il peut y avoir formation d'une couche mouillante contenant essentiellement la phase polaire. On considère ici l'effet sur cette couche mouillante d'un sel ajouté. Dans la limite des faibles concentrations en sel, l'épaisseur d'équilibre se réduit à un résultat obtenu précédemment. Dans la limite des fortes concentrations en sel, l'épaisseur se réduit à une longueur d'écran de Debye multipliée par une fonction de deux paramètres sans dimensions

A Narrative Review of COVID-19 Vaccines

The COVID-19 pandemic has shaken the world since early 2020 and its health, social, economic, and societal negative impacts at the global scale have been catastrophic. Since the early days of the pandemic, development of safe and effective vaccines was judged to be the best possible tool to minimize the effects of this pandemic. Drastic public health measures were put into place to stop the spread of the virus, with the hope that vaccines would be available soon. Thanks to the extraordinary commitments of many organizations and individuals from around the globe and the collaborative effort of many international scientists, vaccines against COVID-19 received regulatory approval for emergency human use in many jurisdictions in less than a year after the identification of the viral sequence. Several of these vaccines have been in use for some time; however, the pandemic is still ongoing and likely to persist for the foreseeable future. This is due to many reasons including reduced compliance with public health restrictions, limited vaccine manufacturing/distribution capacity, high rates of vaccine hesitancy, and the emergence of new variants with the capacity to spread more easily and to evade current vaccines. Here we discuss the discovery and availability of COVID-19 vaccines and evolving issues around mass vaccination programs

Materials compatibility and lubricants research on CFC-refrigerant substitutes: Thermophysical properties

Numerous fluids have been identified as promising alternative refrigerants, but much of the information needed to predict their behavior as pure fluids and as components in mixtures does not exist. In particular, reliable thermophysical properties data and models are needed to predict the performance of the new refrigerants in heating and cooling equipment, and to design and optimize equipment to be reliable and energy efficient. The objective of this project is to provide highly accurate, selected thermophysical properties data for Refrigerants 32, 123, 124, and 125, and to use these data to fit simple and complex equations of state and detailed transport property models. The new data will fill in the gaps in existing data sets and resolve the problems and uncertainties that exist in and between the data sets. This report describes the progress made during the first quarter of this fifteen-month project, which was initiated in late January, 1992