More than one dynamic crossover in protein hydration water

Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network

The Role of Pore Structure of SMFs-based Pd Nanocatalysts in Deactivation Behavioral Pattern Upon Acetylene Hydrogenation Reaction

In this research, SMFs panels were applied for further deposition of CNFs, ZnO and Al2O3 to hydro-genate selectively acetylene to ethylene. To understand the role of different structures of the examined supports, the characterization methods of SEM, ASAP, NH3-TPD and N2 adsorption-desorption isotherms were used. Following the characterization of green oil by FTIR, the presence of more unsaturated constitu-ents and then, more branched hydrocarbons formed upon the reaction over alumina-supported catalyst in comparison with the ones supported on CNFs and ZnO was confirmed, which in turn, could block the pores mouths. Besides the limited hydrogen transfer, the lowest pore diameters of Al2O3 / SMFs close to the sur-face, supported by N2 adsorption-desorption isotherms could explain the fast deactivation of this catalyst, compared to the other ones. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521

The Formation of the Intermetallic-Containing Pd2Sn Alloy: The Creation of the Isolated Adsorption Sites

In the current study, tin-promoted Pd / MWNTs synthesized via polyol process were developed. TEM images evidences resulted in the formation of highly-dispersed Pd-Sn nanoparticles. The formation of Pd2Sn structural phase was confirmed by XRD and TPR techniques, composed mainly of intermetallic spe-cies, supported by XPS results. In this research, we applied intermetallic-containing tin-promoted catalysts for the selective hydrogenation reaction of acetylene as the case study. The presence of a discontinuity in the Arrhenius plots could come from the kinetic factor as a result of change in acetylene coverage on Pd metallic ensembles. The intermetallic-containing assembled catalysts led to the good management of cata-lytic performance due to the creation of isolated adsorption sites on the catalyst surface, resulting in the higher ethylene selectivity. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521

Experiences of Iranian family caregivers supporting individuals with multiple sclerosis: a qualitative study

Family members of patients are often considered informal primary caregivers, particularly for those living with chronic diseases including multiple sclerosis (MS). Caregivers often report increased burden and stress when caring for individuals with chronic care needs. It is important to explore the caregiver experience in the context of MS. The aim of this study is to describe the experiences of family caregivers caring for individuals with Multiple Sclerosis. A purposive sampling method was utilized. A total of eighteen family member caregivers of patients with multiple sclerosis participated in this study. Data were collected through semi-structured and in-depth interviews conducted in the multiple sclerosis society and hospitals of Tabriz in Iran. Data were analyzed using qualitative content analysis assisted by MAXQDA 10 software. Three main categories emerged from interviews about their caregiving experiences. These include1) emotional reactions; 2) caregiver needs; and 3) caregiver expectations. Results of this study demonstrate that family caregivers of individuals with MS show different emotional reactions and have complex needs and expectations from other ‘non-caregiver relatives and society. This study highlights the psychosocial, physical and economic needs of caregivers of individuals with MS and enhances social understanding of this impact of the condition. This may improve the support clinicians provide to family caregivers. There is need to develop targeted interventions that reduce caregiver burden for those caring for individuals with MS

The effects of Momordica charantia on liver function and histological structure

Introduction: The application of herbal plants because of their lower side-effects has been increasing in recent years. Objectives: we aimed to study the effects of hydro-alcoholic extract of Momordica charantia (bitter melon) on liver function and tissue structure in mice. Materials and Methods: This study was conducted on 70 male mice which were randomly designated into 7 groups of 10 and were injected with single doses of 0, 100, 500, 1000, 2000 and 4000 mg/kg and multiple daily dose of 500 mg/kg for 7 days, intraperitoneally. Finally, liver tissues were taken out for histological examinations. Serum samples were assayed for liver enzymes activities of alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase. Also the antioxidant activity of blood and bitter melon were measured. Subsequently, data were analyzed by analysis of variance (ANOVA) and Bonferroni tests using Stata software. Results: The results of the present study showed that a single dose of Momordica charantia fruit extract at doses up to 4000 mg/kg extract does not significant adverse effects on the liver enzymes and tissue structure. Conclusion: Using this drug for short time and low dose has not toxicity effects on liver enzymes activity and tissue structure, hence, it is safe in this range of doses

Evidence of coexistence of change of caged dynamics at Tg and the dynamic transition at Td in solvated proteins

Mossbauer spectroscopy and neutron scattering measurements on proteins embedded in solvents including water and aqueous mixtures have emphasized the observation of the distinctive temperature dependence of the atomic mean square displacements, , commonly referred to as the dynamic transition at some temperature Td. At low temperatures, increases slowly, but it assume stronger temperature dependence after crossing Td, which depends on the time/frequency resolution of the spectrometer. Various authors have made connection of the dynamics of solvated proteins including the dynamic transition to that of glass-forming substances. Notwithstanding, no connection is made to the similar change of temperature dependence of obtained by quasielastic neutron scattering when crossing the glass transition temperature Tg, generally observed in inorganic, organic and polymeric glass-formers. Evidences are presented to show that such change of the temperature dependence of from neutron scattering at Tg is present in hydrated or solvated proteins, as well as in the solvents used unsurprisingly since the latter is just another organic glass-formers. The obtained by neutron scattering at not so low temperatures has contributions from the dissipation of molecules while caged by the anharmonic intermolecular potential at times before dissolution of cages by the onset of the Johari-Goldstein beta-relaxation. The universal change of at Tg of glass-formers had been rationalized by sensitivity to change in volume and entropy of the beta-relaxation, which is passed onto the dissipation of the caged molecules and its contribution to . The same rationalization applies to hydrated and solvated proteins for the observed change of at Tg.Comment: 28 pages, 10 figures, 1 Tabl

Low-Temperature Polymorphic Phase Transition in a Crystalline Tripeptide L-Ala-L-Pro-Gly·H2O Revealed by Adiabatic Calorimetry

We demonstrate application of precise adiabatic vacuum calorimetry to observation of phase transition in the tripeptide l-alanyl-l-prolyl-glycine monohydrate (APG) from 6 to 320 K and report the standard thermodynamic properties of the tripeptide in the entire range. Thus, the heat capacity of APG was measured by adiabatic vacuum calorimetry in the above temperature range. The tripeptide exhibits a reversible first-order solid-to-solid phase transition characterized by strong thermal hysteresis. We report the standard thermodynamic characteristics of this transition and show that differential scanning calorimetry can reliably characterize the observed phase transition with <5 mg of the sample. Additionally, the standard entropy of formation from the elemental substances and the standard entropy of hypothetical reaction of synthesis from the amino acids at 298.15 K were calculated for the studied tripeptide.National Institute of Biomedical Imaging and Bioengineering (U.S.) (EB-003151)National Institute of Biomedical Imaging and Bioengineering (U.S.) (EB-001960)National Institute of Biomedical Imaging and Bioengineering (U.S.) (EB-002026

Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by Swept Area Method

Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, a series of research cruises (5 cruises per year) were carried out by R/V Ferdows-1covering the area from 49 00 E in the west (Khoozestan provice) to 61 25 E in the east (Gwater) in a 5 years program form 2004 up to 2008 (no cruise in 2006). The study area was stratified into 17 strata (A to Q) of which 10 starta (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50m in the Persian Gulf and 10-100m in the Oman Sea. A total of 316 stations were randomly selected. The biomass and CPUA were estimated by Swept Area method. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2004, 2005, 2007 and 2008 were 3.3, 3.9, 2.3 and 2.4 times more than the Oman Sea and totally 70-80% of total biomass was calculated for the Persian Gulf. Also a comparison among 17 starta, the highest biomass was found for starta C & D in the Bushehr province waters. The amount of CPUA for both regions of the Persian Gulf and Oman Sea was compared and it was concluded that in years 2004 and 2005, the mean CPUA in the Persian Gulf was partially higher than the Oman Sea with 1.06 & 1.20 times more; and on the contrary for the next two years this value was higher in the Oman Sea with 1.3 times more. The highest CPUA of demersal resources for the Oman Sea belonged to the strata K & O for years 2004, 2007 and 2008 and for year 2005 was for L and strata. It can be concluded that the north-west of Oman Sea has the best condition of biomass of commercial and non-commercial species and the O stratum will be in the second ranking. With review the mean CPUA in different depth-layers for years 2004, 2005, 2007 and 2008, it was concluded that with increasing the depth, the mean CPUA is decreased in which the CPUA values in depth-layer 10-20m for these years were 8.3, 3.0, 2.1 & 1.6 times more than depth-layer 50-100m. The comparison of mean CPUA for 10 strata of the Persian Gulf showed that in years 2004 and 2005, the mean CPUA of demersal fishes in the Hormuzgan province waters was higher than in Bushehr province waters (1.2 times more). In total, the highest maen CPUA belonged to F (Naiband to Mogham) and G (Mogham to Farour) in Hormuzgan waters. On the contrary, in years 2007 and 2008 this value in Bushehr waters was 1.3 times higher than western part of Hormuzgan waters with the highest value in D stratum(Boordekhoon to Dayyer). Also the comparison of mean CPUA for different depth-layers, it was found that the mean CPUA has ascending trend with increasing the depth, with the highest value in depth-laer of 30-50m in which contains the 55-68% of total biomass. The lowest biomass is found in depth-layers of 10-30m. Totally, the minimum CPUA and biomass for both commercial and non-commercial species belonged to a stratum located in Khouzestan province waters and it was shown the over-exploitation of resources in this area. The comparison between commercial and non-commercial groups in both ecosystems , it was concluded that the density of commercial species was higher than non-commercial ones , and in all years the Persian Gulf indicated higher values than the Oman Sea