Coupled self-organization: Thermal interaction between two liquid films undergoing long-wavelength instabilities

The effects of thermal coupling between two thin liquid layers, separated by a gas layer, are discussed. The liquid layers undergo long-wavelength instabilities driven by gravitational and thermocapillary stresses. To study the dynamics, both a linear stability analysis and a full numerical solution of the thin-film equations are performed. The results demonstrate that the stability properties of the combined system differ substantially from the case where both layers evolve independently from each other. Most prominently, oscillatory instabilities, not present in single-liquid layer configurations, may occur.Comment: 12 pages, 9 figure

Terápiás lehetőségek a gyulladásos bélbetegség állatkísérletes modelljében – összehasonlító vizsgálat [Comparative study of novel therapeutic possibilities in animal experimental model of inflammatory bowel disease]

Introduction: The consequence of inflammatory bowel diseases (IBD) is cytokine-mediated severe local tissue damage. Our aim was to determine the extent of inflammatory response and to influence the morphologic changes during the subacute phase of trinitro-benzene sulfonic acid (TNBS)-induced experimental colitis by oral phosphatidylcholine (PC) and N-methyl-D-aspartate (NMDA) receptor antagonist kynurenic acid therapy. Methods: Sprague-Dawley rats were randomized to control, untreated colitis (ic TNBS), colitis fed with 2% PC-containing diet (3 days pre-treatment +3 days treatment after TNBS induction), colitis with kynurenic acid treatment (on day 6, n = 7) groups. The colitis was characterized by tissue myeloperoxidase and plasma TNF-alpha levels, the extent of tissue damage, structural changes in microvasculature (FITC-dextran staining) and mucosal injury (acridine orange staining) were determined by in vivo confocal laser scanning endomicroscopy (Optiscan Five1, Australia) and conventional histology (hematoxyilin-eosin staining). Results: Significant elevation in myeloperoxidase and TNF-alpha levels with remarkable damage in epithelial structure was detected in the colitis group. Both treatment regimens significantly decreased the level of inflammatory activation but only PC pretreatment could preserve the number of goblet cells and the epithelial structure. Treatment with kynurenic acid did not alter the morphology changes. Conclusion: Oral PC pretreatment is a promising possibility in the therapy of IBDs through decreasing inflammatory reaction and increasing the number of goblet cells

Distinct cytokine patterns may regulate the severity of neonatal asphyxia

Abstract Background Neuroinflammation and a systemic inflammatory reaction are important features of perinatal asphyxia. Neuroinflammation may have dual aspects being a hindrance, but also a significant help in the recovery of the CNS. We aimed to assess intracellular cytokine levels of T-lymphocytes and plasma cytokine levels in moderate and severe asphyxia in order to identify players of the inflammatory response that may influence patient outcome. Methods We analyzed the data of 28 term neonates requiring moderate systemic hypothermia in a single-center observational study. Blood samples were collected between 3 and 6 h of life, at 24 h, 72 h, 1 week, and 1 month of life. Neonates were divided into a moderate (n = 17) and a severe (n = 11) group based on neuroradiological and amplitude-integrated EEG characteristics. Peripheral blood mononuclear cells were assessed with flow cytometry. Cytokine plasma levels were measured using Bioplex immunoassays. Components of the kynurenine pathway were assessed by high-performance liquid chromatography. Results The prevalence and extravasation of IL-1b + CD4 cells were higher in severe than in moderate asphyxia at 6 h. Based on Receiver operator curve analysis, the assessment of the prevalence of CD4+ IL-1β+ and CD4+ IL-1β+ CD49d+ cells at 6 h appears to be able to predict the severity of the insult at an early stage in asphyxia. Intracellular levels of TNF-α in CD4 cells were increased at all time points compared to 6 h in both groups. At 1 month, intracellular levels of TNF-α were higher in the severe group. Plasma IL-6 levels were higher at 1 week in the severe group and decreased by 1 month in the moderate group. Intracellular levels of IL-6 peaked at 24 h in both groups. Intracellular TGF-β levels were increased from 24 h onwards in the moderate group. Conclusions IL-1β and IL-6 appear to play a key role in the early events of the inflammatory response, while TNF-α seems to be responsible for prolonged neuroinflammation, potentially contributing to a worse outcome. The assessment of the prevalence of CD4+ IL-1β+ and CD4+ IL-1β+ CD49d+ cells at 6 h appears to be able to predict the severity of the insult at an early stage in asphyxia

Finite queues at the limit of saturation

Abstract-A wide range of real life systems are modeled by queueing systems with finite capacity buffers. There are well established numerical procedures for the analysis of these queueing models when the load is lower or higher than the system capacity, but these numerical methods become unstable as the load gets close to the system capacity. We present simple modifications of the standard computational methods which remain numerically stable at saturation as well. We consider two specific Markov models: finite quasi birth death (QBD) process and finite Markov fluid queue (MFQ). The first one describes the behavior of queueing systems with discrete buffer content, while the second one describes the behavior of queueing systems with continuous buffer content. The stationary solution of a finite QBD process is a combination of two matrix geometric series while the stationary fluid density of a finite MFQ is a combination of two matrix exponential functions. Apart of this there are several further similarities between the discrete and continuous buffer models at saturation. The proposed solution method exploits the similarities of the models

Changes in muscle fiber density following a stroke

Objectives: Previous studies have revealed a selective functional loss of the large, high-threshold motor units in the paretic muscles after lesion of the upper motor neuron. We set out to Study the degree and the time course of the reorganization of the motor units following a stroke. Methods: Examinations were performed on 59 patients with a unilateral ischemic stroke in the territory of the middle cerebral artery, and on 42 healthy controls. The duration of hemiparesis ranged from 2 weeks to 48 months. The fiber density (FD) in the abductor digiti minimi muscle was determined by means of single-fiber electromyography on both the hemiparetic and the unaffected side in the patients, and unilaterally in the control subjects. Results: The FD was increased on the hemiparetic side relative to the unaffected side and the control group. This change correlated with the severity of the clinical signs. The FD increased during the first 10 months following the stroke and subsequently remained stable. Conclusions: The process of reinnervation in the muscles takes place in the acute phase after stroke. These changes are related to the severity of the symptoms. Significance: Our findings suggest that trans-synaptic degeneration of the spinal motor neurons occurs shortly after the lesion of the upper motor neurons. (C) 2009 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved

Fiber density of the motor units recruited at high and low force output.

Motor units (MUs) are recruited according to the size principle. At low force output, macro-motor unit potentials (macro-MUPs) with small amplitude and area are recorded; MUs with large electrical size fire at high force output. Our objective was to elucidate whether this difference is caused by a higher fiber density (FD) of the MUs recruited at high force output. We measured the FD and respectively the amplitude and the area of the macro-MUPs via single-fiber macro electromyography (EMG) recorded at low and high force output in 48 healthy subjects. The macro-MUPs were significantly larger at high force output than at low force. The FD did not differ at the two force levels. Our findings suggest that the larger electrical size of the high recruitment threshold MUs is due not to a higher FD, but to a larger territory. FD is a robust EMG parameter, independent of the level of the force output. Muscle Nerve 40: 112-114, 2009

The Orexin/Hypocretin System, the Peptidergic Regulator of Vigilance, Orchestrates Adaptation to Stress

The orexin/hypocretin neuropeptide family has emerged as a focal point of neuroscientific research following the discovery that this family plays a crucial role in a variety of physiological and behavioral processes. These neuropeptides serve as powerful neuromodulators, intricately shaping autonomic, endocrine, and behavioral responses across species. Notably, they serve as master regulators of vigilance and stress responses; however, their roles in food intake, metabolism, and thermoregulation appear complementary and warrant further investigation. This narrative review provides a journey through the evolution of our understanding of the orexin system, from its initial discovery to the promising progress made in developing orexin derivatives. It goes beyond conventional boundaries, striving to synthesize the multifaceted activities of orexins. Special emphasis is placed on domains such as stress response, fear, anxiety, and learning, in which the authors have contributed to the literature with original publications. This paper also overviews the advancement of orexin pharmacology, which has already yielded some promising successes, particularly in the treatment of sleep disorders

Low dosage of rimonabant leads to anxiolytic-like behavior via inhibiting expression levels and G-protein activity of kappa opioid receptors in a cannabinoid receptor independent manner

What is known There is an increasing number of studies demonstrating the direct effect of the cannabinoid receptor 1 (CB1) antagonist/inverse agonist rimonabant on the opioid system. The kappa opioid receptors (KORs) are well known to mediate depression- and anxiety-like behavior. Clinical studies on chronic rimonabant administration have revealed that rimonabant leads to a very similar pathophysiology, suggesting a potential impact of rimonabant on KORs. Objectives Our objectives were to examine the putative effects of rimonabant on KOR ligand binding, G-protein activity, protein expression and how all these contribute to the development of depression- and anxiety-like behavior. Results In Chinese hamster ovary (CHO) cell membranes transfected with rat KOR (CHO-rKOR) rimonabant inhibited KOR agonist [3H]U69593 binding in the micromolar range in competition binding experiments and specifically reduced KOR basal activity at lower micromolar concentrations in [35S]GTPγS binding assays. Rimonabant significantly inhibited dynorphin (1-11)-induced [35S]GTPγS binding in micromolar range in CHO-rKOR cells, CB1 knockout (CB1 K.O.) and CB1/CB2 double knockout mouse forebrain membranes. A single dose of i.p. 0.1 mg/kg rimonabant significantly reduced dynorphin (1-11)-induced KOR G-protein activity and KOR protein expression levels 24 h following the administration in both wild type and CB1 K.O. mice forebrain. Furthermore, in elevated plus maze mice showed an anxiolytic-like effect upon rimonabant injection that could be reversed by 1 mg/kg KOR antagonist norbinaltorphimine. The anxiolytic-like effects were further confirmed with the light-dark box test. Conclusion Rimonabant reduced KOR ligand binding, receptor mediated G-protein activity and protein expression level, which overall leads to altered anxiety-like behavior