3,881 research outputs found
Experimental Modeling of Flavonoid-Biomembrane Interactions
Nonspecific interactions of flavonoids with lipids can alter the membrane's features (e.g., thickness and fluctuations) as well as influence their therapeutic potentials. However, relatively little is known about the details of how flavonoids interact with lipid components. Structure-dependent interactions of a variety of flavonoids with phospholipid monolayers on a mercury (Hg) film electrode were established by rapid cyclic voltammetry (RCV). The data revealed that flavonoids adopting a planar configuration altered the membrane properties more significantly than nonplanar flavonoids. Quercetin, rutin, and tiliroside were selected for follow-up experiments with Langmuir monolayers, Brewster angle microscopy (BAM), and small-angle X-ray scattering (SAXS). Relaxation phenomena in DOPC monolayers and visualization of the surface with BAM revealed a pronounced monolayer stabilization effect with both quercetin and tiliroside, whereas rutin disrupted the monolayer structure rendering the surface entirely smooth. SAXS showed a monotonous membrane thinning for all compounds studied associated with an increase in the mean fluctuations of the membrane. Rutin, quercetin, and tiliroside decreased the bilayer thickness of DOPC by ∼0.45, 0.8, and 1.1 Å at 6 mol %, respectively. In addition to the novelty of using lipid monolayers to systematically characterize the structure-activity relationship (SAR) of a variety of flavonoids, this is the first report investigating the effect of tiliroside with biomimetic membrane models. All the flavonoids studied are believed to be localized in the lipid/water interface region. Both this localization and the membrane perturbations have implications for their therapeutic activity
Screening for Venous Thromboembolism in Asymptomatic Trauma Patients: Effective in High Risk Patients
Hypothesis:
Through data analysis of a large cohort of trauma patients, a clinically applicable protocol can be developed based on various predisposing factors for VTE in asymptomatic patients. By isolating the factors that make these patients high risk for VTE, we can effectively lower the incidence of PE in hospitalized trauma patients.https://jdc.jefferson.edu/patientsafetyposters/1001/thumbnail.jp
Pickering emulsions for food and drinks
The scientific literature from 2016 onwards on aspects of Pickering emulsions relevant to food and drink has been reviewed. Ongoing unsolved issues surrounding the general Pickering stabilization mechanism are discussed, such as contact angles of microscopic, irregularly size particles; adsorption and desorption barriers; and competition and complex formation with other surface-active species. The main types of emulsion that have been studied are surveyed: oil-in-water (O/W), water-in-oil (W/O), water-in-water (W/W) and multiple emulsions. There is still a lack of food-grade particle types suitable for W/O and therefore multiple emulsions. Finally, work on different types of Pickering emulsifiers is discussed, the principal types being organic crystals, prolamins, cellulose, starch and microgel particles. The latter are highlighted as particularly versatile in terms of their properties and the food components from which they can be formed
Recent developments in food foams
The scientific literature from 2015 onwards with respect to foams and thin films in the context of foods has been reviewed. Proteins are the dominant foaming agents in foods, and investigations of the classic, meringue-forming egg white protein still dominate the literature because the unique properties of this system are still not properly understood. The current drive of many studies is to find suitable replacers of egg proteins, driven by consumer trends for more plant-based alternatives. This has led to investigations of the stabilizing properties of various protein aggregates, ‘nanoparticles’ and microgel particles as Pickering-type stabilizers of foams (Pickering foams). At the same time, other work has sought to manipulate the surface properties of biopolymer- and nonbiopolymer–based particles by chemical means, to make the particles adsorb more strongly. Few, truly novel foam stabilizers have emerged, but two include saponin aggregates and bacteria as particle-type stabilizers
Patient-Specific Prosthetic Fingers by Remote Collaboration - A Case Study
The concealment of amputation through prosthesis usage can shield an amputee
from social stigma and help improve the emotional healing process especially at
the early stages of hand or finger loss. However, the traditional techniques in
prosthesis fabrication defy this as the patients need numerous visits to the
clinics for measurements, fitting and follow-ups. This paper presents a method
for constructing a prosthetic finger through online collaboration with the
designer. The main input from the amputee comes from the Computer Tomography
(CT) data in the region of the affected and the non-affected fingers. These
data are sent over the internet and the prosthesis is constructed using
visualization, computer-aided design and manufacturing tools. The finished
product is then shipped to the patient. A case study with a single patient
having an amputated ring finger at the proximal interphalangeal joint shows
that the proposed method has a potential to address the patient's psychosocial
concerns and minimize the exposure of the finger loss to the public.Comment: Open Access articl
On the Origin of Seemingly Non-Surface Active Particles Partitioning between Phase Separated Solutions of Incompatible Non-Adsorbing Polymers and Their Adsorption at the Phase Boundary.
We have computed the free energy per unit area (i.e., interfacial tension) between a solid surface and two co-existing polymer solutions, where there is no specific interaction between the particles and either polymer, via self-consistent field calculations. Several different systems have been studied, including those where the two polymers differ in molecular weight (Mw) by a factor of ~ 2, or where the polymers have the same Mw but one set of chains is branched with the other being linear. In the absence of any enthalpic contribution resulting from adsorption on the particle, the differences in free energy per unit area resulting from the polymer depleted regions around the particles in the two co-exiting phases are found to be ~ 1 μN m-1. Although this value may seem rather small, this difference is more than capable of inducing the partitioning of particles of 100 nm in size (or larger) into the phase with the lower interfacial free energy at a solid surface. By examining the density profile variation of the polymers close to the solid surface, we can also infer information about the wettability and contact angle (Θ) of the solid particle at the interface between the two co-existing phases. This leads to the conclusion that for all systems of this type, when the incompatibility between the two polymers is sufficiently large, will be close to 90°
Analysis of symmetries in models of multi-strain infections
In mathematical studies of the dynamics of multi-strain diseases caused by antigenically diverse pathogens, there is a substantial interest in analytical insights. Using the example of a generic model of multi-strain diseases with cross-immunity between strains, we show that a significant understanding of the stability of steady states and possible dynamical behaviours can be achieved when the symmetry of interactions between strains is taken into account. Techniques of equivariant bifurcation theory allow one to identify the type of possible symmetry-breaking Hopf bifurcation, as well as to classify different periodic solutions in terms of their spatial and temporal symmetries. The approach is also illustrated on other models of multi-strain diseases, where the same methodology provides a systematic understanding of bifurcation scenarios and periodic behaviours. The results of the analysis are quite generic, and have wider implications for understanding the dynamics of a large class of models of multi-strain diseases
Parametric study of EEG sensitivity to phase noise during face processing
<b>Background: </b>
The present paper examines the visual processing speed of complex objects, here faces, by mapping the relationship between object physical properties and single-trial brain responses. Measuring visual processing speed is challenging because uncontrolled physical differences that co-vary with object categories might affect brain measurements, thus biasing our speed estimates. Recently, we demonstrated that early event-related potential (ERP) differences between faces and objects are preserved even when images differ only in phase information, and amplitude spectra are equated across image categories. Here, we use a parametric design to study how early ERP to faces are shaped by phase information. Subjects performed a two-alternative force choice discrimination between two faces (Experiment 1) or textures (two control experiments). All stimuli had the same amplitude spectrum and were presented at 11 phase noise levels, varying from 0% to 100% in 10% increments, using a linear phase interpolation technique. Single-trial ERP data from each subject were analysed using a multiple linear regression model.
<b>Results: </b>
Our results show that sensitivity to phase noise in faces emerges progressively in a short time window between the P1 and the N170 ERP visual components. The sensitivity to phase noise starts at about 120–130 ms after stimulus onset and continues for another 25–40 ms. This result was robust both within and across subjects. A control experiment using pink noise textures, which had the same second-order statistics as the faces used in Experiment 1, demonstrated that the sensitivity to phase noise observed for faces cannot be explained by the presence of global image structure alone. A second control experiment used wavelet textures that were matched to the face stimuli in terms of second- and higher-order image statistics. Results from this experiment suggest that higher-order statistics of faces are necessary but not sufficient to obtain the sensitivity to phase noise function observed in response to faces.
<b>Conclusion: </b>
Our results constitute the first quantitative assessment of the time course of phase information processing by the human visual brain. We interpret our results in a framework that focuses on image statistics and single-trial analyses
Release of Angiotensin-Converting Enzyme (ACE) and Dipeptidyl Peptidase-IV (DPP-IV) inhibitory peptides from oilseed proteins – a bioinformatic prediction approach
Acute kidney disease and renal recovery : consensus report of the Acute Disease Quality Initiative (ADQI) 16 Workgroup
Consensus definitions have been reached for both acute kidney injury (AKI) and chronic kidney disease (CKD) and these definitions are now routinely used in research and clinical practice. The KDIGO guideline defines AKI as an abrupt decrease in kidney function occurring over 7 days or less, whereas CKD is defined by the persistence of kidney disease for a period of > 90 days. AKI and CKD are increasingly recognized as related entities and in some instances probably represent a continuum of the disease process. For patients in whom pathophysiologic processes are ongoing, the term acute kidney disease (AKD) has been proposed to define the course of disease after AKI; however, definitions of AKD and strategies for the management of patients with AKD are not currently available. In this consensus statement, the Acute Disease Quality Initiative (ADQI) proposes definitions, staging criteria for AKD, and strategies for the management of affected patients. We also make recommendations for areas of future research, which aim to improve understanding of the underlying processes and improve outcomes for patients with AKD
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