The mammalian hyaluronidase degrades hyaluronic acid by the cleavage of the β-1,4-glycosidic bond furnishing a tetrasaccharide molecule as the main product which is a highly angiogenic and potent inducer of inflammatory cytokines. Ursolic acid 1, isolated from Prismatomeris tetrandra, was identified as having the potential to develop inhibitors of hyaluronidase. A series of ursolic acid analogues were either synthesized via structure modification of ursolic acid 1 or commercially obtained. The evaluation of the inhibitory activity of these compounds on the hyaluronidase enzyme was conducted. Several structural, topological and quantum chemical descriptors for these compounds were calculated using semi empirical quantum chemical methods. A quantitative structure activity relationship study (QSAR) was performed to correlate these descriptors with the hyaluronidase inhibitory activity. The statistical characteristics provided by the best multi linear model (BML) (R2 = 0.9717, R2cv = 0.9506) indicated satisfactory stability and predictive ability of the developed model. The in silico molecular docking study which was used to determine the binding interactions revealed that the ursolic acid analog 22 had a strong affinity towards human hyaluronidase.
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Σάββατο 13 Φεβρουαρίου 2016
IJMS, Vol. 17, Pages 143: Hyaluronidase Inhibitory Activity of Pentacylic Triterpenoids from Prismatomeris tetrandra (Roxb.) K. Schum: Isolation, Synthesis and QSAR Study
SafeFish: New NRC funded project will start in September 2016
The project is aimed at studying the carry-over of plant peptides, natural toxins and other bioactive compounds from "green" feed into the fish.
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Low-temperature photoluminescence in CuIn 5 S 8 single crystals
Abstract
Photoluminescence (PL) spectra of CuIn5S8 single crystals grown by Bridgman method have been studied in the wavelength region of 720–1020 nm and in the temperature range of 10–34 K. A broad PL band centred at 861 nm (1.44 eV) was observed at T = 10 K. Variations of emission band has been studied as a function of excitation laser intensity in the 0.5– 60.2 mW cm−2 range. Radiative transitions from shallow donor level located at 17 meV below the bottom of the conduction band to the acceptor level located at 193 meV above the top of the valence band were suggested to be responsible for the observed PL band. An energy level diagram showing transitions in the band gap of the crystal has been presented.
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Exact solutions of the Drinfel’d–Sokolov–Wilson equation using Bäcklund transformation of Riccati equation and trial function approach
Abstract
In this paper, two integration schemes are employed to obtain solitons, singular periodic waves and other types of solutions of the Drinfel'd–Sokolov–Wilson equation. The two schemes studied in this paper are the Bäcklund transformation of Riccati equation and the trial function approach. The corresponding constraint conditions of the solutions are also given.
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Acute Care Pediatric Nurse Practitioner: The 2014 Practice Analysis
Practice research serves as the certification framework for validating advanced practice roles and updating national qualifying examinations. This national study describes the current practice of the acute care pediatric nurse practitioner (AC PNP) to inform an update of the Certified Pediatric Nurse Practitioner–Acute Care (CPNP-AC) examination content outline.
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Inhibition-based first-generation electrochemical biosensors: theoretical aspects and application to 2,4-dichlorophenoxy acetic acid detection
Abstract
In this work, several theoretical aspects involved in the first-generation inhibition-based electrochemical biosensor measurements have been discussed. In particular, we have developed a theoretical-methodological approach for the characterization of the kinetic interaction between alkaline phosphatase (AlP) and 2,4-dichlorophenoxy acetic acid (2,4-D) as representative inhibitor studied by means of cyclic voltammetry and amperometry. Based on these findings, a biosensor for the fast, simple, and inexpensive determination of 2,4-D has been developed. The enzyme has been immobilized on screen-printed electrodes (SPEs). To optimize the biosensor performances, several carbon-based SPEs, namely graphite (G), graphene (GP), and multiwalled carbon nanotubes (MWCNTs), have been evaluated. AlP was immobilized on the electrode surface by means of polyvinyl alcohol with styryl-pyridinium groups (PVA-SbQ) as cross-linking agent. In the presence of ascorbate 2-phosphate (A2P) as substrate, the herbicide has been determined, thanks to its inhibition activity towards the enzyme catalyzing the oxidation of A2P to ascorbic acid (AA). Under optimum experimental conditions, the best performance in terms of catalytic efficiency has been demonstrated by MWCNTs SPE-based biosensor. The inhibition biosensor shows a linearity range towards 2,4-D within 2.1–110 ppb, a LOD of 1 ppb, and acceptable repeatability and stability. This analysis method was applied to fortified lake water samples with recoveries above 90 %. The low cost of this device and its good analytical performances suggest its application for the screening and monitoring of 2,4-D in real matrices.
Graphical Abstract
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Fractionating power and outlet stream polydispersity in asymmetrical flow field-flow fractionation. Part I: isocratic operation
Abstract
Asymmetrical flow field-flow fractionation (As-FlFFF) has become the most commonly used of the field-flow fractionation techniques. However, because of the interdependence of the channel flow and the cross flow through the accumulation wall, it is the most difficult of the techniques to optimize, particularly for programmed cross flow operation. For the analysis of polydisperse samples, the optimization should ideally be guided by the predicted fractionating power. Many experimentalists, however, neglect fractionating power and rely on light scattering detection simply to confirm apparent selectivity across the breadth of the eluted peak. The size information returned by the light scattering software is assumed to dispense with any reliance on theory to predict retention, and any departure of theoretical predictions from experimental observations is therefore considered of no importance. Separation depends on efficiency as well as selectivity, however, and efficiency can be a strong function of retention. The fractionation of a polydisperse sample by field-flow fractionation never provides a perfectly separated series of monodisperse fractions at the channel outlet. The outlet stream has some residual polydispersity, and it will be shown in this manuscript that the residual polydispersity is inversely related to the fractionating power. Due to the strong dependence of light scattering intensity and its angular distribution on the size of the scattering species, the outlet polydispersity must be minimized if reliable size data are to be obtained from the light scattering detector signal. It is shown that light scattering detection should be used with careful control of fractionating power to obtain optimized analysis of polydisperse samples. Part I is concerned with isocratic operation of As-FlFFF, and part II with programmed operation.
Graphical abstract
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Biological trait analysis and stability of lambda-cyhalothrin resistance in the house fly, Musca domestica L. (Diptera: Muscidae)
Abstract
House flies, Musca domestica L., (Diptera: Muscidae), are pests of poultry and have the ability to develop resistance to insecticides. To design a strategy for resistance management, life history traits based on laboratory observations were established for lambda-cyhalothrin-resistant, susceptible and reciprocal crosses of M. domestica strains. Bioassay results showed that the lambda-cyhalothrin-selected strain developed a resistance ratio of 98.34 compared to its susceptible strain. The lambda-cyhalothrin-selected strain had a relative fitness of 0.26 and lower fecundity, hatchability, lower number of next generation larvae, and net reproductive rate compared with its susceptible strain. Mean population growth rates, such as intrinsic rate of population increase, and biotic potential were lower for the lambda-cyhalothrin-selected strain compared to its susceptible strain. Resistance to lambda-cyhalothrin, indoxacarb, and abamectin was unstable while resistance to bifenthrin and methomyl was stable in the lambda-cyhalothrin-selected strain of M. domestica. Development of resistance can cost considerable fitness for the lambda-cyhalothrin-selected strain. The present study provided useful information for making potential management strategies to delay resistance development in M. domestica.
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hνSABR: Photochemical Dose–Response Bead Screening in Droplets
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Facilitating triple rhomboid flaps for meningomyelocele defect closure using a honeycomb structure as a template
Abstract
Purpose
Various reconstruction options are available for the soft-tissue coverage of meningomyelocele defects. For small defects, primary closure or local single flaps may be sufficient, while large defects require more complex reconstructive techniques. This study suggests an easy way for surgeons to close large meningomyelocele defects using triple rhomboid flaps.
Methods
The hexagonal structure of a honeycomb was considered when planning for the coverage of large meningomyelocele defects. The intact skin around the defect was imagined as multiple hexagons, which allowed us to plan triple rhomboid flaps correctly and more easily. This technique was used in seven patients with defects ranging from 7 × 5 to 12 × 8 cm in size.
Results
No major postoperative complications were seen. Minimal dehiscence was observed in two patients and healed secondarily.
Conclusions
The honeycomb modification for planning triple rhomboid flaps is an easy, practical, and memorable approach for surgeons reconstructing large meningomyelocele defects.
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Age-related change in handgrip strength in men and women: is muscle quality a contributing factor?
Abstract
Age-related changes in muscle quality and muscle mass in the forearm, which relate to decline in handgrip strength (HGS), have not been reported. The purpose of this study was to investigate the relationships between age-related declines in HGS and loss of muscle thickness and/or muscle quality in the forearm of 613 adults (306 men and 307 women) aged 20–89. Anterior forearm muscle thickness (MT-ulna) and HGS were measured using an ultrasound and a hand dynamometer, respectively, in the dominant hand. Muscle quality (fMQ) was defined as a ratio of HGS to MT-ulna. HGS was similar among younger (ages 20–29, 30–39, and 40–49) groups and was progressively lower with increasing age in both sexes. MT-ulna was similar between ages 20–29 and 60–69 in men and between ages 20–29 and 70–79 in women. In men, MT-ulna was lower in ages 70–79 and 80–89 compared with other age groups. In women, MT-ulna was lower in ages 80–89 compared with ages 20–29 and 40–49. In both men and women, fMQ was identical among younger (ages 20–29, 30–39, and 40–49) groups. After that fMQ was progressively lower with age in both men and women. The results indicated that age-related decline in HGS is associated with fMQ, but it appears to be accelerated after the seventh decade due to muscle loss.
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Numéro 2/2016. Questions
Publication date: Available online 12 February 2016
Source:Revue des Maladies Respiratoires
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Numéro 2/2016. Réponses
Publication date: Available online 12 February 2016
Source:Revue des Maladies Respiratoires
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Protective role of Th17 cells in pulmonary infection
Source:Vaccine
Author(s): Jitendra Singh Rathore, Yan Wang
Th17 cells are characterized as preferential producer of interleukins including IL-17A, IL-17F, IL-21 and IL-22. Corresponding receptors of these cytokines are expressed on number of cell types found in the mucosa, including epithelial cells and fibroblasts which constitute the prime targets of the Th17-associated cytokines. Binding of IL-17 family members to their corresponding receptors lead to modulation of antimicrobial functions of target cells including alveolar epithelial cells. Stimulated alveolar epithelial cells produce antimicrobial peptides and are involved in granulepoesis, neutrophil recruitment and tissue repair. Mucosal immunity mediated by Th17 cells is protective against numerous pulmonary pathogens including extracellular bacterial and fungal pathogens. This review focuses on the protective role of Th17 cells during pulmonary infection, highlighting subset differentiation, effector cytokines production, followed by study of the binding of these cytokines to their corresponding receptors, the subsequent signaling pathway they engender and their effector role in host defense.
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Αλέξανδρος Γ. Σφακιανάκης Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,0030693260717...
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heory of COVID-19 pathogenesis Publication date: November 2020Source: Medical Hypotheses, Volume 144Author(s): Yuichiro J. Suzuki ScienceD...
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