2,331 research outputs found
Thermodynamically self-consistent liquid state theories for systems with bounded potentials
The mean spherical approximation (MSA) can be solved semi-analytically for
the Gaussian core model (GCM) and yields - rather surprisingly - exactly the
same expressions for the energy and the virial equations. Taking advantage of
this semi-analytical framework, we apply the concept of the self-consistent
Ornstein-Zernike approximation (SCOZA) to the GCM: a state-dependent function K
is introduced in the MSA closure relation which is determined to enforce
thermodynamic consistency between the compressibility route and either the
virial or energy route. Utilizing standard thermodynamic relations this leads
to two different differential equations for the function K that have to be
solved numerically. Generalizing our concept we propose an
integro-differential-equation based formulation of the SCOZA which, although
requiring a fully numerical solution, has the advantage that it is no longer
restricted to the availability of an analytic solution for a particular system.
Rather it can be used for an arbitrary potential and even in combination with
other closure relations, such as a modification of the hypernetted chain
approximation.Comment: 11 pages, 11 figures, submitted to J. Chem. Phy
Phase behaviour of a symmetrical binary fluid mixture
We have investigated the phase behaviour of a symmetrical binary fluid
mixture for the situation where the chemical potentials and of
the two species differ. Attention is focused on the set of interparticle
interaction strengths for which, when , the phase diagram exhibits
both a liquid-vapor critical point and a tricritical point. The corresponding
phase behaviour for the case is investigated via
integral-equation theory calculations within the mean spherical approximation
(MSA), and grand canonical Monte Carlo (GCMC) simulations. We find that two
possible subtypes of phase behaviour can occur, these being distinguished by
the relationship between the critical lines in the full phase diagram in the
space of temperature, density, and concentration. We present the detailed form
of the phase diagram for both subtypes and compare with the results from GCMC
simulations, finding good overall agreement. The scenario via which one subtype
evolves into the other, is also studied, revealing interesting features.Comment: 22 pages, 13 figure
Assessment of processing technologies which may improve the nutritional composition of dairy products – Overview of progress
Among consumers there is a growing demand for food products with a natural nutritional-physiological advantage over comparable conventional products. As part of an EU funded project, ALP is examining the possible impact of processing on nutritionally valuable milk components, using the example of conjugated linoleic acids (CLA). The extent to which processing influences the CLA content of the end product was determined by literature research and own investigations of organic and conventional butter. Furthermore, new chemical, sensory-based and bio crystallization methods were evaluated by ALP and the University of Kassel to determine the oxidation stability of butter. In a further step the storage stability of CLA enriched and conventional butter was examined and the different methods will be compared. As a third objective a process for low-input CLA enrichment of milk fat (with a focus on alpine butter) has been developed. Since the process selected for the work is a physical enrichment process, it is accepted by international organic farming and food groups. Among the many benefits ascribed to CLA, it is believed to be an effective agent against cancer. The demand for foods with properties that promote human health is growing. The dairy industry has the opportunity to meet this demand by developing new dairy products with a nutritional-physiological function for the functional food market
Allogeneic hematopoietic cell transplantation as curative therapy for patients with non-Hodgkin lymphoma: Increasingly successful application to older patients
AbstractNon-Hodgkin lymphoma (NHL) constitutes a collection of lymphoproliferative disorders with widely varying biological, histological, and clinical features. For the B cell NHLs, great progress has been made due to the addition of monoclonal antibodies and, more recently, other novel agents including B cell receptor signaling inhibitors, immunomodulatory agents, and proteasome inhibitors. Autologous hematopoietic cell transplantation (auto-HCT) offers the promise of cure or prolonged remission in some NHL patients. For some patients, however, auto-HCT may never be a viable option, whereas in others, the disease may progress despite auto-HCT. In those settings, allogeneic HCT (allo-HCT) offers the potential for cure. Over the past 10 to 15 years, considerable progress has been made in the implementation of allo-HCT, such that this approach now is a highly effective therapy for patients up to (and even beyond) age 75 years. Recent advances in conventional lymphoma therapy, peritransplantation supportive care, patient selection, and donor selection (including the use of alternative hematopoietic cell donors), has allowed broader application of allo-HCT to patients with NHL. As a result, an ever-increasing number of NHL patients over age 60 to 65 years stand to benefit from allo-HCT. In this review, we present data in support of the use of allo-HCT for patients with diffuse large B cell lymphoma, follicular lymphoma, and mantle cell lymphoma. These histologies account for a large majority of allo-HCTs performed for patients over age 60 in the United States. Where possible, we highlight available data in older patients. This body of literature strongly supports the concept that allo-HCT should be offered to fit patients well beyond age 65 and, accordingly, that this treatment should be covered by their insurance carriers
Effects of Climate Change on Ticks and Tick-Borne Diseases in Europe
Zoonotic tick-borne diseases are an increasing health burden in Europe and there is speculation that this is partly due to climate change affecting vector biology and disease transmission. Data on the vector tick Ixodes ricinus suggest that an extension of its northern and altitude range has been accompanied by an increased prevalence of tick-borne encephalitis. Climate change may also be partly responsible for the change in distribution of Dermacentor reticulatus. Increased winter activity of I. ricinus is probably due to warmer winters and a retrospective study suggests that hotter summers will change the dynamics and pattern of seasonal activity, resulting in the bulk of the tick population becoming active in the latter part of the year. Climate suitability models predict that eight important tick species are likely to establish more northern permanent populations in a climate-warming scenario. However, the complex ecology and epidemiology of such tick-borne diseases as Lyme borreliosis and tick-borne encephalitis make it difficult to implicate climate change as the main cause of their increasing prevalence. Climate change models are required that take account of the dynamic biological processes involved in vector abundance and pathogen transmission in order to predict future tick-borne disease scenarios
Optical spectroscopy of complex open 4-shell ions Sn-Sn
We analyze the complex level structure of ions with many-valence-electron
open [Kr] 4 sub-shells (=7-4) with ab initio
calculations based on configuration-interaction many-body perturbation theory
(CI+MBPT). Charge-state-resolved optical and extreme ultraviolet (EUV) spectra
of Sn-Sn ions were obtained using an electron beam ion trap.
Semi-empirical spectral fits carried out with the orthogonal parameters
technique and Cowan code calculations lead to 90 identifications of
magnetic-dipole transitions and the determination of 79 energy
ground-configuration levels, questioning some earlier EUV-line assignments. Our
results, the most complete data set available to date for these ground
configurations, confirm the ab initio predictive power of CI+MBPT calculations
for the these complex electronic systems.Comment: 18 pages, 5 figure
Episodic Stream Acidification Caused by Atmospheric Deposition of Sea Salts at Acadia National Park, Maine, United States
Major episodic acidifications were observed on several occasions in first-order brooks at Acadia National Park, Mount Desert Island, Maine. Short-term declines of up to 2 pH units and 130-mu-eq L-1 acid-neutralizing capacity were caused by HCl from soil solutions, rather than by H2SO4 or HNO3 from precipitation, because (1) SO4 concentrations were constant or decreased during the pH depression, (2) Cl concentrations were greatest at the time of lowest pH, and (3) Na:Cl ratios decreased from values much greater than those in precipitation (a result of chemical weathering), to values equal to or less than those in precipitation. Dilution, increases in NO3 concentrations, or increased export or organic acidity from soils were insufficient to cause the observed decreases in pH. These data represent surface water acidifications due primarily to an ion exchange salt effect of Na+ for H+ in soil solution, and secondarily to dilution, neither of which is a consequence of acidic deposition. The requisite conditions for a major episodic salt effect acidification include acidic soils, and either an especially salt-laden wet precipitation event, or a period of accumulation of marine salts from dry deposition, followed by wet inputs
Structure Factor and Electronic Structure of Compressed Liquid Rubidium
We have applied the quantal hypernetted-chain equations in combination with
the Rosenfeld bridge-functional to calculate the atomic and the electronic
structure of compressed liquid-rubidium under high pressure (0.2, 2.5, 3.9, and
6.1 GPa); the calculated structure factors are in good agreement with
experimental results measured by Tsuji et al. along the melting curve. We found
that the Rb-pseudoatom remains under these high pressures almost unchanged with
respect to the pseudoatom at room pressure; thus, the effective ion-ion
interaction is practically the same for all pressure-values. We observe that
all structure factors calculated for this pressure-variation coincide almost
into a single curve if wavenumbers are scaled in units of the Wigner-Seitz
radius although no corresponding scaling feature is observed in the
effective ion-ion interaction.This scaling property of the structure factors
signifies that the compression in liquid-rubidium is uniform with increasing
pressure; in absolute Q-values this means that the first peak-position ()
of the structure factor increases proportionally to ( being the
specific volume per ion), as was experimentally observed by Tsuji et al.Comment: 18 pages, 11 figure
Dynamics in binary cluster crystals
As a result of the application of coarse-graining procedures to describe
complex fluids, the study of systems consisting of particles interacting
through bounded, repulsive pair potentials has become of increasing interest in
the last years. A well known example is the so-called Generalized Exponential
Model (GEM-), for which the interaction between particles is described by
the potential . Interactions with
lead to the formation of a novel phase of soft matter consisting of cluster
crystals. Recent studies on the phase behavior of binary mixtures of GEM-
particles have provided evidence for the formation of novel kinds of alloys,
depending on the cross interactions between the two species. This work aims to
study the dynamic behavior of such binary mixtures by means of extensive
molecular dynamics simulations, and in particular to investigate the effect of
the addition of non-clustering particles on the dynamic scenario of
one-component cluster crystals. Analogies and differences with the
one-component case are revealed and discussed by analyzing self- and collective
dynamic correlators.Comment: 17 pages, 8 figures, submitted to JSTA
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