Values Of Γ2 Research Articles

Modeling the extraction of bioactive compounds of green and red camu-camu peel and identification using UPLC-MS/MS

The use of kinetic modeling data for the extraction of bioactive compounds is essential for food industries. This work aimed to investigate which mathematical model best fits the extraction of bioactive compounds from camu-camu peel and to evaluate the effect of drying by hot air convection (60 ºC). Four mathematical models (parabolic diffusion, power law, hyperbolic and pseudo-second order) were applied to assess the extraction conditions. To describe the kinetics and data modeling the peels went through ultrasound-assisted extraction (UAE) for 1 h, 6 h, 12 h, and 24 h with water and water-ethanol (50:50 v/v) as solvents. The hyperbolic and pseudo-second order mathematical models presented the best fitting to the experimental data with lower values of γ², MSE, RMSE, and NRMSE, in addition to values closer to 1 for EF. The extracts went through UPLC-MS/MS and nine compounds were identified in the peels: cyanidin 3-o-glucoside, delphinidin, quercetin, myricetin, rutin, gallic acid, chlorogenic acid p-coumaric and ellagic acid. Therefore, dried camu-camu peels still have antioxidant potential, especially when extracted for 12 h with water-ethanol (50:50 v/v) as solvent.

Lipid acyl chain protrusion induced by the influenza virus hemagglutinin fusion peptide detected by NMR paramagnetic relaxation enhancement

The glycoprotein spikes of membrane-enveloped viruses include a subunit that catalyzes fusion (joining) of the viral and target cell membranes. For influenza virus, this is subunit 2 of hemagglutinin which has a ∼ 20-residue N-terminal fusion peptide (Fp) region that binds target membrane. An outstanding question is whether there are associated membrane changes important for fusion. Several computational studies have found increased “protrusion” of lipid acyl chains near Fp, i.e. one or more chain carbons are closer to the aqueous region than the headgroup phosphorus. Protrusion may accelerate initial joining of outer leaflets of the two membranes into a stalk intermediate. In this study, higher protrusion probability in membrane with vs. without Fp is convincingly detected by larger Mn2+-associated increases in chain 13C NMR transverse relaxation rates (Γ2's). Data analysis provides a ratio Γ2,neighbor/Γ2,distant for lipids neighboring vs. more distant from the Fp. The calculated ratio depends on the number of Fp-neighboring lipids and the experimentally-derived range of 4 to 24 matches the range of increased protrusion probabilities from different simulations. For samples either with or without Fp, the Γ2 values are well-fitted by an exponential decay as the 13C site moves closer to the chain terminus. The decays correlate with free-energy of protrusion proportional to the number of protruded -CH2 groups, with free energy per -CH2 of ∼0.25 kBT. The NMR data support one major fusion role of the Fp to be much greater protrusion of lipid chains, with highest protrusion probability for chain regions closest to the headgroups.

Quantitative Paramagnetic NMR-Based Analysis of Protein Orientational Dynamics on Membranes: Dissecting the KRas4B-Membrane Interactions.

Peripheral membrane proteins can adopt distinct orientations on the surfaces of lipid bilayers that are often short-lived and challenging to characterize by conventional experimental methods. Here we describe a robust approach for mapping protein orientational landscapes through quantitative interpretation of paramagnetic relaxation enhancement (PRE) data arising from membrane mimetics with spin-labeled lipids. Theoretical analysis, followed by experimental verification, reveals insights into the distinct properties of the PRE observables that are generally distorted in the case of stably membrane-anchored proteins. To suppress the artifacts, we demonstrate that undistorted Γ2 values can be obtained via transient membrane anchoring, based on which a computational framework is established for deriving accurate orientational ensembles obeying Boltzmann statistics. Application of the approach to KRas4B, a classical peripheral membrane protein whose orientations are critical for its functions and drug design, reveals four distinct orientational states that are close but not identical to those reported previously. Similar orientations are also found for a truncated KRas4B without the hypervariable region (HVR) that can sample a broader range of orientations, suggesting a confinement role of the HVR geometrically prohibiting severe tilting. Comparison of the KRas4B Γ2 rates measured using nanodiscs containing different types of anionic lipids reveals identical Γ2 patterns for the G-domain but different ones for the HVR, indicating only the latter is able to selectively interact with anionic lipids.

On the 2-domination Number of Cylinders with Small Cycles

Domination-type parameters are difficult to manage in Cartesian product graphs and there is usually no general relationship between the parameter in both factors and in the product graph. This is the situation of the domination number, the Roman domination number or the 2-domination number, among others. Contrary to what happens with the domination number and the Roman domination number, the 2-domination number remains unknown in cylinders, that is, the Cartesian product of a cycle and a path and in this paper, we will compute this parameter in the cylinders with small cycles. We will develop two algorithms involving the (min, +) matrix product that will allow us to compute the desired values of γ2(Cn□Pm), with 3 ≤ n ≤ 15 and m ≤ 2. We will also pose a conjecture about the general formula for the 2-domination number in this graph class.

Modelling of Blood Lactate Time-Courses During Exercise and/or the Subsequent Recovery: Limitations and Few Perspectives.

Because lactate is an important metabolic intermediate and a signalling molecule between/within cells/organs, it appears essential to be able to describe the kinetics of this central molecule, during and/or after physical exercise. The present study aimed to confront three models and their approaches [Freund and co-workers (F&co), Beneke and co-workers (B&co), and Quittmann and co-workers (Q&co)] to investigate the lactate exchange (γ1) and removal (γ2) abilities (min−1) during and/or after exercise. Nine healthy male subjects performed 3- and 6-min easy, moderate, and heavy exercise. Blood lactate concentration (BLC) was measured every 5 s over the entire period of exercise and recovery. Approaches differ depending on the domain in which the model is applied: considering exercise and part of the recovery (B&co and Q&co) or the entire period of recovery (F&co). The different approaches result in differing γ1 and γ2 values. Model fitting is closer to the experimental values following the method (model and approach) of F&co. Complementary analyses show that consideration of (i) exercise drastically impairs the quality of model fitting and therefore the γ1 and γ2 values and (ii) the entire period of recovery considerably improves the quality of fits and therefore of the γ1 and γ2 values. We conclude that (i) it is neither realistic nor reliable to take into account exercise and recovery in the same model and (ii) the longer the period of recovery studied, the better the quality of the γ1 and γ2 values.

Solubility and thermodynamic analysis of vinpocetine in various mono solvents at different temperatures

In the present study, the solubility of vinpocetine in ten commonly used solvents at different temperatures range of T = 298.2–323.2 K was examined and correlate the solubility data with Apelblat and Van’t Hoff models and lastly the dissolution thermodynamic parameters of vinpocetine in each solvent were estimated. It was observed that the vinpocetine solubility found less in water and determined to be better in non-polar solvents. Both (Apelblat and Van’t Hoff) models are found suitable to correlate the measured solubility data, still, the Van’t Hoff equation demonstrated to be more precise for the correlation of solubilities of VPN in investigated solvents. The maximum value of activity coefficients (γ2) for vinpocetine was observed in water, this could be due to low solubility of vinpocetine in water, while the value of γ2 was observed lowest in Transcutol owing to maximum solubility of vinpocetine in Transcutol. The conclusions of thermodynamic parameters analysis of vinpocetine in various studied solvents brought out that the vinpocetine solubilization process was endothermic, non-spontaneous and entropy-driven. The outcomes of the present study would provide enormous support in vinpocetine solubilization, pre-formulation and dosage form development in pharmaceuticals.

Theoretical analysis of the binding of a positron and pair-annihilation in fluorinated benzene molecules

The binding of a positron to fluorobenzene molecules was theoretically demonstrated at Hartree-Fock level of multi-component molecular orbital theory. We confirmed that (i) 1,2-difluorobenzene, 1,2,3-trifluorobenzene, 1,2,3,4-tetrafluorobenzene molecules have bound states for a positron, and (ii) their positron affinity (PA) and two photon pair-annihilation rate (Γ2) are strongly correlated with their dipole moment. Analyzing the Γ2 values for each electronic molecular orbital in all the fluorobenzene molecules, we found that the electronic valence orbitals, consisting of 2p atomic orbitals of fluorine atoms, have the dominant contribution to the total Γ2 value.

Visceral adiposity and insulin resistance in the prediction of gestational diabetes mellitus in early pregnancy: a prospective observational study

Objective The aim was to study the relationship between abdominal adiposity and insulin resistance in the prediction of gestational diabetes mellitus (GDM) in early pregnancy. Background There is a positive association between high prepregnancy BMI and risk of GDM. Patients and methods This prospective cohort study included 83 women at 11–14 weeks for abdominal adiposity measurement and at 16–22 weeks for oral glucose tolerance test measurement. The patients were divided into two groups: group 1included patients who did not develop GDM and group 2included patients who developed GDM. This study was conducted at the Obstetrics and Gynecology Department, Menoufia University Hospital between March 2015 and March 2017. Results There was a significant statistical difference between both groups as regards visceral adipose tissue (VAT) depth (P = 0.001) with a mean ± SD of VAT depth (5.85 ± 0.47) increase in group 2. There was a positive relationship between visceral adiposity and the homestatic model assessment of insulin resistance and a negative relationship between visceral adiposity and insulin sensitivity. The γ2 values examining the association between VAT depth and measured homestatic model assessment of insulin resistance or insulin sensitivity were higher than the γ2 examining the association between BMI and measured homestatic model assessment of insulin resistance or insulin sensitivity index. Conclusion Measurement of visceral adiposity during the 11–14 weeks' gestation by ultrasound might improve the performance of screening for GDM better than BMI.

Microstructure Evolution and Selective Corrosion Resistance in Underwater Multi-pass 2101 Duplex Stainless Steel Welding Joints

A recently developed promising material, 2101 lean duplex stainless steel, represents an alternative to 304 austenite stainless steel. In this work, multi-pass 2101 weld joints were fabricated using the flux-cored arc welding method in a hyperbaric chamber. The pressure varied from 0 to 0.75 MPa. The evolution of the welding process and microstructure was investigated. γ2 formation in the reheated zones of the WM and HAZ was not uniform. The closer the reheated zone is to the subsequent heat source, the greater the γ2 formation in the reheated zone. Sufficient primary austenite transformation inhibited Cr2N precipitation and the subsequent intragranular γ2 formation in the reheated weld passes of the 0.45 MPa weld metal. The localized corrosion resistance of each zone of the 0.45 MPa DSS joint was measured using non-destructive double-loop electrochemical potentiokinetic reactivation tests. The localized corrosion was induced by γ2 and Cr2N. The root region of the 0.45 MPa weld metal underwent two subsequent welding thermal cycles, which induced increased γ2 formation and lower resistance to corrosion because of the decreased pitting resistance value of γ2. The correlation between microstructure evolution and the distribution of selective corrosion was determined.

Herding Behavior Post Initial Public Offering In Indonesia Stock Exchange

This research was conducted to test whether there is a herding behavior post Initial Public Offering (IPO) in Indonesia Stock Exchange. Domestic transactions on the Indonesia Stock Exchange are rising year by year along with the increased of IPO emissions. The existence of underpricing phenomenon causes a domino effect (herding) that arises on potential investors after the IPO. This study used Cross-Sectional Absolute Deviation (CSAD) method to detect herding behavior. The data used were daily price data of IPO shares from the 1st day until the 30th day after IPO period 2005-2015. Hypothesis testing was done using regression analysis by means of CSAD variable as dependent variable and return market as independent variable. The result of this research indicated that there was a herding behavior post -IPO in Indonesia Stock Exchange period 2005-2015 period. It is shown by the negative and significant value of γ2 (0.013 <0.05).

Anisotropy of iron-platinum-arsenide Ca10(PtnAs8)(Fe2−xPtxAs2)5 single crystals

The upper critical field Hc2 anisotropy of Ca10(PtnAs8)(Fe2−xPtxAs2)5 (n = 3, 4) single crystals with long FeAs interlayer distance (d) was studied by angular dependent resistivity measurements. A scaling of the angular dependent resistivity was realized for both single crystals using the anisotropic Ginzburg-Landau (AGL) approach with an appropriate anisotropy parameter γ. The AGL scaling parameter γ increases with decreasing temperature and reaches a value of about 10 at 0.8Tc for both single crystals. These values are much larger than those of other iron-based superconductors (FeSCs). Remarkably, the values of γ2 show an almost linear increase with the FeAs/FeSe interlayer distance d for FeSCs. Compared to cuprates, FeSCs are less anisotropic, indicating that two dimensionality of the superconductivity is intrinsically weak.

Reduced Model Captures Mg2+-RNA Interaction Free Energy of Riboswitches

The stability of RNA tertiary structures depends heavily on Mg2+. The Mg2+-RNA interaction free energy that stabilizes an RNA structure can be computed experimentally through fluorescence-based assays that measure Γ2+, the number of excess Mg2+ associated with an RNA molecule. Previous explicit-solvent simulations predict that the majority of excess Mg2+ ions interact closely and strongly with the RNA, unlike monovalent ions such as K+, suggesting that an explicit treatment of Mg2+ is important for capturing RNA dynamics. Here we present a reduced model that accurately reproduces the thermodynamics of Mg2+-RNA interactions. This model is able to characterize long-timescale RNA dynamics coupled to Mg2+ through the explicit representation of Mg2+ ions. KCl is described by Debye-Hückel screening and a Manning condensation parameter, which represents condensed K+ and models its competition with condensed Mg2+. The model contains one fitted parameter, the number of condensed K+ ions in the absence of Mg2+. Values of Γ2+ computed from molecular dynamics simulations using the model show excellent agreement with both experimental data on the adenine riboswitch and previous explicit-solvent simulations of the SAM-I riboswitch. This agreement confirms the thermodynamic accuracy of the model via the direct relation of Γ2+ to the Mg2+-RNA interaction free energy, and provides further support for the predictions from explicit-solvent calculations. This reduced model will be useful for future studies of the interplay between Mg2+ and RNA dynamics.

Analysis of the spin splitting of maxima of quantum oscillations of the resistivity of n-Bi-Sb semiconductor alloys in a magnetic field parallel to the bisector axis

In samples of semiconductor alloys n-Bi0.93Sb0.07 with different electron concentrations (n1 = 8 × 1015 cm−3, n2 = 1.2 × 1017 cm−3, and n3 = 1.9 × 1018 cm−3), dependences of the electrical resistivity on magnetic fields up to 45 T parallel to the current and the bisector axis (H ‖ C1 ‖ j) have been measured at temperatures of 1.5, 4.5, and 10 K. The obtained dependences ρ22(H) demonstrate quantum oscillations of the resistivity (Shubnikov-de Haas effect), and, in high magnetic fields, there is a resistivity maximum far away from other maxima. On assumption that this maximum is related to the spin-split Landau level N = 0− for electrons of the main ellipsoid, the spin-splitting parameters are calculated for electrons of the main ellipsoid: γ1 = 0.87, γ2 = 0.8, and γ3 = 0.73. Using these values, the oscillation maxima can be reliably related to the numbers of split Landau levels for electrons of the main and secondary ellipsoids. The dependences of the resistivity ρ11 and the Hall coefficient R31.2 on magnetic field have been measured in a transverse magnetic field at H ‖ C1 and j ‖ C2 on the sample with the electron concentration n4 = 1.4 × 1017 cm−3. Using similar analysis, the spin-splitting parameter is found to be γ4 = 0.85, which is close to the value of γ2 = 0.8 obtained for the sample with close electron concentration (n2 = 1.2 × 1017 cm−3) during the measurements in a longitudinal magnetic field. The quantum oscillation maxima of Hall coefficient R31.2 are shifted to the range of high magnetic fields as compared to the quantum oscillation maxima of resistivity ρ11.

NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS

The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, γ, and three distinct values are taken for the cavity (γ1), the shell (γ2), and the ISM (γ3) with the condition γ2 < γ1, γ3. This low value of γ2 accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a stable evolution and the Vishniac instability does not lead to the fragmentation of the shock as predicted by the theory.

Adsorption characteristics of sodium dodecylsulfate and cetylpyridinium chloride at air/water, air/formamide and air/water–formamide interfaces

The adsorption model developed by Kralchevsky and co-workers, the Kralchevsky–Danov–Broze–Mehreteab (KDBM) model, has been applied to fit the surface tension data in the submicellar region of sodium dodecylsulfate (SDS) and cetylpyridinium chloride (CPC) in water, water+50wt.% formamide (FA) and FA media. The KDBM model satisfactorily fits the surface tension data and from the fitting surface density of surfactant monomer (Γ1), surface density of counterion (Γ2) and electrostatic potential at the air–solution interface were evaluated. The value of Γ1 decreases as the FA content in the medium increases due to decreasing solvophobicity, but the value of Γ2 does not follow this trend. For both SDS and CPC the maximum value of the counterion binding constant (Γ2/Γ1) is almost same (about 0.8) in water and FA, but much low (about 0.3–0.5) in 50% FA. In all the three media, on increasing the concentration of SDS or CPC the surface potential passes through a maximum in the low concentration region.

Defect‐free half‐V‐mode ferroelectric liquid‐crystal device

Abstract— The horizontal chevron defect found in a half‐V‐mode ferroelectric‐liquid‐crystal (HV‐FLC) device can be suppressed by lowering the FLC's total free energy. The energy levels between spontaneous polarization (PS) up and down domains were degenerated by asymmetrical‐alignment treatments. The difference in the polar surface coefficient (γ2) was the key to suppressing the alignment defect. Alignment layers with opposite surface polarities and different anchoring energies were applied to control the sign and value of γ2. The asymmetric cells of PIrub ‐ PIplasma (rubbed polyimide and plasma‐treated polyimide surfaces), PVArub ‐ PIplasma (rubbed polyvinyl alcohol and plasma‐treated polyimide surfaces), and PVArub ‐ PIplasma (both rubbed PI and PVA) alignment conditions presented defect‐free alignment textures under a slow‐cooling process. Among these different alignment treatments, the PVArub ‐ PIrub treated cell demonstrated the best alignment result, benefited by the largest difference in polar surface coefficient.

27.3: Horizontal Chevron Defect Free Half‐V Mode Ferroelectric Liquid Crystal Devices Based on Asymmetrical Hybrid Alignment Techniques

AbstractBase on FLC free energy, the asymmetrical alignment techniques were proposed to suppress the alignment defects of half‐V mode ferroelectric liquid crystal (HV‐FLC) devices. Alignment layers with opposite surface polarities and different anchoring energies were applied to controlled the sign and value of polar surface coefficient (γ2), respectively. The asymmetrical cells of PIrub‐ PIplasma (rubbed polyimide (PI) and plasma treated PI surfaces), PVArub‐PIplasma (rubbed polyvinyl alcohol (PVA) and plasma treated PI surfaces), and PVArub‐PIrub (both rubbed PI and PVA) alignment conditions present mono‐domain alignment textures under slow cooling process. Among these alignment pairs, the PVArub‐PIrub), treated cell, with larger difference in γ2 values, appeared to have better alignment. A 2.4″ prototype TFT‐LCD was presented by PVArub‐PIrub treated surfaces.

High-frequency susceptibility of a multilayered ferromagnetic system with two-dimensional inhomogeneities

This paper reports on the results of the investigation of the high-frequency susceptibility of a layered ferromagnetic structure in which, apart from a periodic change in the magnetic anisotropy parameter from layer to layer, this parameter varies along layers according to a random law (the superlattice with two-dimensional phase inhomogeneities). The evolution of the frequency dependence of the imaginary part of the averaged Green’s function in the range of the energy gap (band gap) in the spectrum of waves propagating along the superlattice axis due to the change in the relative root-mean-square fluctuations of the phase γ2 has been studied at the boundaries of the odd Brillouin zones. It has been found that, for all odd Brillouin zones, the imaginary part of the Green’s function exhibits a universal behavior: the peak corresponding to the edge of the band gap with a lower frequency remains unchanged, and the peak corresponding to the edge of the band gap with a higher frequency is smoothed with an increase in the quantity γ2. These effects, which were initially revealed at the boundary of the first Brillouin zone of the sinusoidal superlattice, have been explained, as before, by the specific features of the energy conservation laws for the incident and scattered waves in the lattice with two-dimensional inhomogeneities. It has been demonstrated that an increase in the Brillouin zone number leads to a decrease in the value of γ2 at which the peak at the edge of the band gap with a higher frequency disappears.

Storm-Induced Circulation in Lunenburg Bay of Nova Scotia: Observations and Numerical Simulations

Abstract An extreme weather event (Hurricane Juan) made landfall in Nova Scotia, Canada, in September 2003. The storm produced an ∼70-cm storm surge and ∼40 cm s−1 coastal currents in Lunenburg Bay, registered by a coastal observing system. A fine-resolution (60 m) coastal circulation model is used to examine the response of Lunenburg Bay to Hurricane Juan. The model is forced by local wind stress at the sea surface, and tides and remotely generated waves specified at model open boundaries. The model performance is assessed in terms of γ2, the variance of the model errors normalized by the observed variance. The model reproduces very well the observed surface elevations with γ2 values of less than 0.05, and reasonably well the observed currents with γ2 values between 0.2 and 1.1 in the bay during Hurricane Juan. The model–data comparisons demonstrate that the coastal circulation in the bay is significantly affected by local wind associated with the storm. The model results are also used to demonstrate the importance of nonlinear dynamics in the barotropic response of the bay to the storm.

On signed distance-k-domination in graphs

The signed distance-k-domination number of a graph is a certain variant of the signed domination number. If v is a vertex of a graph G, the open k-neighborhood of v, denoted by Nk(v), is the set Nk(v) = {u: u ≠ v and d(u, v) ⩽ k}. Nk[v] = Nk(v) ⋃ {v} is the closed k-neighborhood of v. A function f: V → {−1, 1} is a signed distance-k-dominating function of G, if for every vertex \(v \in V, f(N_k [v]) = \sum\limits_{u \in N_k [v]} {f(u) \geqslant 1} \). The signed distance-k-domination number, denoted by γk,s(G), is the minimum weight of a signed distance-k-dominating function on G. The values of γ2,s(G) are found for graphs with small diameter, paths, circuits. At the end it is proved that γ2,s(T) is not bounded from below in general for any tree T.