Search results for "Aggregation"

Greedy versus Dynamic Channel Aggregation Strategy in CRNs: Markov Models and Performance Evaluation

2011

Part 1: - PE-CRN 2011 Workshop; International audience; In cognitive radio networks, channel aggregation techniques which aggregate several channels together as one channel have been proposed in many MAC protocols. In this paper, we consider elastic data traffic and spectrum adaptation for channel aggregation, and propose two new strategies named as Greedy and Dynamic respectively. The performance of channel aggregation represented by these strategies is evaluated using continuous time Markov chain models. Moreover, simulation results based on various traffic distributions are utilized in order to evaluate the validity and preciseness of the mathematical models.

La décomposition canonique et la cointégration

1994

This paper has introduced state space models for cointegrated time series. In doing so, the notion of cointegration is slightly generalized. We develop the notion of dynamic aggregation link with error correction model and common trends.

Cetylpyridinium chloride promotes disaggregation of SARS-CoV-2 virus-like particles

2022

ABSTRACT Background SARS-CoV-2 is continuously disseminating worldwide. The development of strategies to break transmission is mandatory. Aim of the study To investigate the potential of cetylpyridinium chloride (CPC) as a viral inhibitor. Methods SARS-CoV-2 Virus Like-Particles (VLPs) were incubated with CPC, a potent surfactant routinely included in mouthwash preparations. Results Concentrations of 0.05% CPC (w/v) commonly used in mouthwash preparations are sufficient to promote the rupture of SARS-CoV-2 VLP membranes. Conclusion Including CPC in mouthwashes could be a prophylactic strategy to keep SARS-CoV-2 from spreading.

Microscopic Study of Injectable Steroids: Effects of Postmixing Time on Particle Aggregation

2020

Background: Epidural steroid injection (ESI) is a common practice for pain treatment since 1953. In 2014, the FDA issued a warning about ESI. Studies have focused on the effect of the particle size and their ability to generate harmful aggregates. Although steroid aggregates provide longer times for reabsorption, therefore a longer anti-inflammatory effect, they are potentially harmful to the central nervous system via embolic mechanisms. Previous studies have established that steroidal aggregates with asizes over 100 μm are potentially able to occlude blood vessels. Studies by Tiso et al and Benzon et al addressed the role of steroids on CNS adverse events, with similar outcomes. The main …

Low risk of intracranial emergency in patients with minor head injury treated with antiplatelet therapy.

2021

The route to protein aggregate superstructures: Particulates and amyloid-like spherulites.

2015

AbstractDepending on external conditions, native proteins may change their structure and undergo different association routes leading to a large scale polymorphism of the aggregates. This feature has been widely observed but is not fully understood yet. This review focuses on morphologies, physico-chemical properties and mechanisms of formation of amyloid structures and protein superstructures. In particular, the main focus will be on protein particulates and amyloid-like spherulites, briefly summarizing possible experimental methods of analysis. Moreover, we will highlight the role of protein conformational changes and dominant forces in driving association together with their connection w…

Thermal induced conformational changes involved in the aggregation pathways of beta-lactoglobulin.

2004

Aggregation of proteins appears to be associated most often with conformational and structural changes that lead to exposure of some apolar residues. Depending on the native structure of the protein in exam, aggregation is a process that involves different mechanisms, whose time of occurrence and interplay can depend upon temperature. To single out information about the multistages of the aggregation pathway, here we investigate the thermally induced conformational and structural changes of the beta-lactoglobulin (BLG). The experimental approach consists in studying steady-state fluorescence spectra of intrinsic chromophores, two tryptophans, and Anylino-Naphthalene-Sulfonate dye (ANS) mole…

Molecular topology as novel strategy for discovery of drugs with aβ lowering and anti-aggregation dual activities for Alzheimer's disease.

2014

Background and Purpose: In this study, we demonstrate the use of Molecular topology (MT) in an Alzheimer's disease (AD) drug discovery program. MT uses and expands upon the principles governing the molecular connectivity theory of numerically characterizing molecular structures, in the present case, active anti-AD drugs/agents, using topological descriptors to build models. Topological characterization has been shown to embody sufficient molecular information to provide strong correlation to therapeutic efficacy. Experimental Approach: We used MT to include multiple bioactive properties that allows for the identification of multifunctional single agent compounds, in this case, the dual func…

Self-assembly of programmed building blocks into structurally uniform dendrimers.

2005

Selective and independent dimerization of tri- and tetraurea derivatives was used to build up dendritic assemblies which are uniform in size and structure. Dendrimers with the total molecular masses of about 25 000 g/mol were obtained. The existence of uniform assemblies was proved by 1H and 1H DOSY NMR experiments and also by dynamic light scattering.

The Tempered Polymerization of Human Neuroserpin

2012

Neuroserpin, a member of the serpin protein superfamily, is an inhibitor of proteolytic activity that is involved in pathologies such as ischemia, Alzheimer's disease, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). The latter belongs to a class of conformational diseases, known as serpinopathies, which are related to the aberrant polymerization of serpin mutants. Neuroserpin is known to polymerize, even in its wild type form, under thermal stress. Here, we study the mechanism of neuroserpin polymerization over a wide range of temperatures by different techniques. Our experiments show how the onset of polymerization is dependent on the formation of an intermediate mon…