213 research outputs found
Thin films flowing down inverted substrates: Three dimensional flow
We study contact line induced instabilities for a thin film of fluid under
destabilizing gravitational force in three dimensional setting. In the previous
work (Phys. Fluids, {\bf 22}, 052105 (2010)), we considered two dimensional
flow, finding formation of surface waves whose properties within the
implemented long wave model depend on a single parameter,
, where is the capillary number and is
the inclination angle. In the present work we consider fully 3D setting and
discuss the influence of the additional dimension on stability properties of
the flow. In particular, we concentrate on the coupling between the surface
instability and the transverse (fingering) instabilities of the film front. We
furthermore consider these instabilities in the setting where fluid viscosity
varies in the transverse direction. It is found that the flow pattern strongly
depends on the inclination angle and the viscosity gradient
Expression of human beta-defensins-1, 2 and 4 mRNA in human lung tumor tissue: a pilot study
To analyze the patterns of human beta-defensin-1, 2, 4 (hBDs) expression in human lung tumors. Materials and Methods: Tissue samples of surgically resected human lung tumors (squamous cell carcinoma (SCC), n = 10; adenocarcinoma (AC), n = 10) paired with conditionally normal tissue samples were analized for expression of hBD-1, 2, 4 mRNA by semiquantitive RT-PCR. Results: In a number of studied lung cancer tissue samples, overexpression of defensin mRNA was registered: hBD-1 mRNA (50% of SCC and 60% AC), hBD-2 mRNA (60% of SCC and 50% of AC) or hBD-4 (40% of SCC and 20% AC). No correlation was detected between the levels of hBD-1, hBD-2 and hBD-4 mRNA and histological type, differentiation grade of the tumor, and the stage of the disease, as well as the content of hBD-2 peptide in blood serum of lung cancer patients. Conclusion: Human beta-defensins-1 and -2 are often up-regulated in human lung tumors.Цель: проанализировать особенности экспрессии мРНК бета-дефенсинов-1, 2, 4 (hBDs) в ткани опухоли легкого человека.
Материалы и методы: с помощью метода полуколичественного RT-PCR-анализа изучали уровень экспрессии мРНК
hBD-1, 2, 4 в образцах ткани хирургически удаленных опухолей легкого человека (плоскоклеточный рак — ПКР, n = 10;
аденокарцинома — AК, n = 10) по сравнению с образцами условно-нормальной ткани легкого тех же пациентов. Результаты:
в ряде исследованных образцов опухолей легкого выявлена повышенная экспрессия мРНК hBD-1 (50% ПКР и 60% AК),
hBD-2 (60% ПКР и 50% АК) или hBD-4 (40% ПКР и 20% AК). Зависимости между уровнем экспрессии бета-дефенсинов
и гистологическим типом опухоли, стадией заболевания и содержанием пептида hBD-2 в сыворотке крови больных не
установлено. Выводы: в ткани опухоли легкого человека часто активирована экспрессия hBD-1 и hBD-2
Evolution of the cosmic ray anisotropy above 10^{14} eV
The amplitude and phase of the cosmic ray anisotropy are well established
experimentally between 10^{11} eV and 10^{14} eV. The study of their evolution
into the energy region 10^{14}-10^{16} eV can provide a significant tool for
the understanding of the steepening ("knee") of the primary spectrum. In this
letter we extend the EAS-TOP measurement performed at E_0 around 10^{14} eV, to
higher energies by using the full data set (8 years of data taking). Results
derived at about 10^{14} and 4x10^{14} eV are compared and discussed. Hints of
increasing amplitude and change of phase above 10^{14} eV are reported. The
significance of the observation for the understanding of cosmic ray propagation
is discussed.Comment: 4 pages, 3 figures, accepted for publication on ApJ Letter
Three-dimensional localized coherent structures of surface turbulence. III Experiment and model validation
The paper continues a series of publications devoted to the 3D nonlinear
localized coherent structures on the surface of vertically falling liquid
films. The work is primarily focussed on experimental investigations. We study:
(i) instabilities and transitions leading to 3D coherent structures; (ii)
characteristics of these structures. Some nonstationary effects are also
studied numerically. Our experimental results, as well as the results of other
investigators, are in a good agreement with our theoretical and numerical
predictions.Comment: 42 pages, 15 figure
Stable radiation-controlling boundary conditions for the generalized harmonic Einstein equations
This paper is concerned with the initial-boundary value problem for the
Einstein equations in a first-order generalized harmonic formulation. We impose
boundary conditions that preserve the constraints and control the incoming
gravitational radiation by prescribing data for the incoming fields of the Weyl
tensor. High-frequency perturbations about any given spacetime (including a
shift vector with subluminal normal component) are analyzed using the
Fourier-Laplace technique. We show that the system is boundary-stable. In
addition, we develop a criterion that can be used to detect weak instabilities
with polynomial time dependence, and we show that our system does not suffer
from such instabilities. A numerical robust stability test supports our claim
that the initial-boundary value problem is most likely to be well-posed even if
nonzero initial and source data are included.Comment: 27 pages, 4 figures; more numerical results and references added,
several minor amendments; version accepted for publication in Class. Quantum
Gra
The East-West method: an exposure-independent method to search for large scale anisotropies of cosmic rays
The measurement of large scale anisotropies in cosmic ray arrival directions
at energies above 10^13 eV is performed through the detection of Extensive Air
Showers produced by cosmic ray interactions in the atmosphere. The observed
anisotropies are small, so accurate measurements require small statistical
uncertainties, i.e. large datasets. These can be obtained by employing ground
detector arrays with large extensions (from 10^4 to 10^9 m^2) and long
operation time (up to 20 years). The control of such arrays is challenging and
spurious variations in the counting rate due to instrumental effects (e.g. data
taking interruptions or changes in the acceptance) and atmospheric effects
(e.g. air temperature and pressure effects on EAS development) are usually
present. These modulations must be corrected very precisely before performing
standard anisotropy analyses, i.e. harmonic analysis of the counting rate
versus local sidereal time. In this paper we discuss an alternative method to
measure large scale anisotropies, the "East-West method", originally proposed
by Nagashima in 1989. It is a differential method, as it is based on the
analysis of the difference of the counting rates in the East and West
directions. Besides explaining the principle, we present here its mathematical
derivation, showing that the method is largely independent of experimental
effects, that is, it does not require corrections for acceptance and/or for
atmospheric effects. We explain the use of the method to derive the amplitude
and phase of the anisotropy and we demonstrate its power under different
conditions of detector operation
Landscape science: a Russian geographical tradition
The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability
Practical Aspects of Clinical Manifestations, Pathogenesis and Therapy of Alcoholic Liver Disease and Non-alcoholic Fatty Liver Disease: Expert Opinion
Aim: to present the results of an expert discussion of modern aspects of the clinical manifestations, pathogenesis and treatment of alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD).Key points. ALD and NAFLD are characterized by high prevalence and have a significant impact on public health. For the diagnosis of liver pathology, it is important to determine the stage of fibrosis and the severity of the exacerbation of the disease. In the treatment of ALD, it is recommended to achieve abstinence, proper nutrition, the appointment of B vitamins, drugs with cytoprotective activity. In severe hepatitis, corticosteroids may be prescribed. In the treatment of NAFLD, diet and lifestyle modification, weight loss, the use of insulin sensitizers, vitamin E, statins (in the presence of hyperlipidemia) and drugs with metabolic activity are effective.Currently, a point of view is being actively expressed about the synergism of the action of alcohol and the metabolic syndrome on the development of fibrosis, cirrhosis, and hepatocellular carcinoma. The current international consensus recommends a change in the nomenclature of NAFLD and ALD and proposes the terms “metabolically associated steatotic liver disease” and “metabolically associated alcoholic liver disease”.Conclusion. The closeness of the clinical manifestations and pathogenesis of NAFLD and ALD justifies attention to drugs with metabolic activity, which are recommended by the Russian Gastroenterological Association and Russian Scientific Liver Society for the treatment of these diseases. The experts support the suggestion to quantify alcohol consumption in patients with NAFLD in order to change the management of patients, if necessary
The role of statins on helicobacter pylori eradication: Results from the european registry on the management of h. pylori (hp-eureg)
Statins could increase the effectiveness of Helicobacter pylori eradication therapies due to their anti-inflammatory effect. The aim of this study was to analyze the impact of this therapeutic association in real life. This is a multicenter, prospective, non-interventional study aimed at evaluating the management of H. pylori by European gastroenterologists. Patients were registered in an e-CRF by AEG-REDCap from 2013 to 2020. The association between statin use and H. pylori eradication effectiveness was evaluated through multivariate analysis. Overall, 9988 and 705 patients received empirical and culture-guided treatment, respectively. Overall, statin use was associated with higher effectiveness in the empirical group (OR = 1.3; 95%CI = 1.1-1.5), but no association was found with first-line treatment effectiveness (N = 7738); as an exception, statin use was specifically associated with lower effectiveness of standard triple therapy (OR = 0.76; 95%CI = 0.59-0.99). In the rescue therapy empirical group (N = 2228), statins were associated with higher overall effectiveness (OR = 1.9; 95%CI = 1.4-2.6). However, sub-analyses by treatment schemes only confirmed this association for the single-capsule bismuth quadruple therapy (OR = 2.8; 95%CI = 1.3-5.7). No consistent association was found between statin use and H. pylori therapy effectiveness. Therefore, the addition of statins to the usual H. pylori treatment cannot be currently recommended to improve cure rates. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
The Inviscid Limit and Boundary Layers for Navier-Stokes Flows
The validity of the vanishing viscosity limit, that is, whether solutions of
the Navier-Stokes equations modeling viscous incompressible flows converge to
solutions of the Euler equations modeling inviscid incompressible flows as
viscosity approaches zero, is one of the most fundamental issues in
mathematical fluid mechanics. The problem is classified into two categories:
the case when the physical boundary is absent, and the case when the physical
boundary is present and the effect of the boundary layer becomes significant.
The aim of this article is to review recent progress on the mathematical
analysis of this problem in each category.Comment: To appear in "Handbook of Mathematical Analysis in Mechanics of
Viscous Fluids", Y. Giga and A. Novotn\'y Ed., Springer. The final
publication is available at http://www.springerlink.co
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