31 research outputs found
Advanced glycation end products formation inhibition through standardized crude extract of punica granatum L. stem bark
Formation of advanced glycation end products (AGEs) under hyperglycemic condition in diabetes mellitus results in micro/macro-angiopathy disorders. Juice, leaves, or peel of pomegranate have shown antioxidant or antiglycation effects. Pomegranate stem barks which are hugely wasted during the pruning season could be a good source of phyto-based anti-AGEs. This study evaluated standardized pomegranate stem barks extract in term of antioxidant activity, antiglycation potential and also its effect on lipid formation and glucose consumption in 3T3-L1 cells.Various extraction conditions were performed including types of solvents, time and type of extraction methods. Phytochemical analysis of extracts was carried by highperformance liquid chromatography-pulsed amperometric detector (HPLC-PAD), gas chromatography-mass spectroscopy and spectrophotometric methods. Evaluation of antioxidant activity was performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′- Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and metal chelating activity. Anti glycation activity of the extract was evaluated in bovine serum albumin (BSA)/glucose or BSA/methylglyoxal (MGO) bioassay systems in presence or absence of samples. Antiglycation property was measured by determination of the level of formation of fructosamine, protein carbonyl and AGE or loss of thiol group. Also, effect of extract on glucose consumption and lipid formation in 3T3-L1 cell line in media containing MGO was investigated in vitro. The result showed that eight hour extraction with methanol using Soxhlet extraction (SM8) was the best extraction process in term of total polyphenolic compounds (59.69 ± 2.913 mg gallic acid equivalent (GAE)/g dry weight (DW), DPPH scavenging capacity [half maximal effective concentration (EC50) 14.99 ± 1.18 mg/L], ABTS●+ radical scavenging equal to 2.636 mM trolox equivalent antioxidant capacity (TEAC)/100 g DW and metal chelation activity (EC50 888.1±48.38). Standardization of SM8 extract by HPLC-PAD showed gallic acid as 0.19% and catechin 0.03% of the extract. SM8 extract reduced formation of AGE significantly (p<0.01) by 77% in concentration of 250 μg /ml. Moreover, it reduced protein carbonyl (60.2%) and fructosamine formation (33.99 %) and simultaneously inhibited thiol group loss (by 1.84 folds). The SM8 extract increased glucose consumption (by 1.95 folds) in 3T3-L1 cells in glycemic condition. In conclusion, it is recommended that pomegranate stem bark extract as a potential source of raw material to be further investigated for the development of health supplement with AGEs inhibitory properties
The role of problem-solving skills training in the amount of aggression control in athletic performance
This study aimed to determine the level of education, solving strategies, aggressive behavior of male basketball athletes. Quasi-experimental method with pre-test - post-test and control group. 220 athletes in male basketball teams randomly selected as subjects and divided in the two groups (experimental group and control group). Buss and Perry Aggression Questionnaire using the rate of overall aggression, physical and verbal problem-solving strategies before and after a training period (variable of aggression, including physical aggression, verbal, physical, hostility and anger) were investigated. The results showed that training-solving strategies has a significant effect (05/0p ≤) on reducing verbal aggression, physical aggression, hostility, anger, aggression of men basketball subjects
Improvement of mechanical strength and electrical conductivity in 6xxx series aluminum conductor alloys
The industrial requirement for low density, high strength, and desirable electrical conductivity (EC) have led to the development of Al-Mg-Si conductor alloys for the power transmission line. The precipitates, dislocations, solute atoms, and grain boundaries result in strengthening the Al-Mg-Si conductor alloys. However, these give rise to electrical resistivity due to disruptions in atomic periodicity in a crystal structure. Accordingly, the parameters improving the strength cause the electrical resistivity in Al-Mg-Si conductor alloys, showing conflicting behaviors of strength and EC. Therefore, the concurrent improvement in strength and EC turns out as a challenging issue. In this study, better combinations of strength and EC in Al-Mg-Si conductor alloys were obtained through (a) optimum principal alloying elements (Mg and Si); (b) natural aging and the modification of the thermo-mechanical treatment; (c) additional alloying elements (Ag and Cu). In the first part of this study, the effect of the various Mg/Si ratios (2, 1.5, 1, 0.86) on the strength and EC of Al-Mg-Si conductor alloys was investigated. The Mg content was kept constant (0.65 wt.%) while the Si amounts were changed. It was found that the peak strength increased with decreasing the Mg/Si ratio while the corresponding EC reduced. Therefore, a longer aging time was required for the alloys with a lower Mg/Si ratio to fulfill the minimum required EC (52.5 %IACS). The alloy with an Mg/Si ratio of 0.86 showed the highest peak strength among all alloys. However, prolonging the aging time (>34 h) was essential to exceed EC (52.5 %IACS), causing a significant drop in the strength with a narrow window of strength and EC. The alloy with Mg/Si ratio of ~ one showed the highest strength in the range of EC (52.5-54 %IACS). The developed strength model exhibited that the higher strength of this alloy could correspond to the higher contributions of the precipitate strengthening, strain hardening, and solute hardening. However, if EC is the main concern, the alloy with Mg/Si ratio of ~ 1.5 showed a better trade-off between strength and EC at high end EC (54-56 %IACS). In the second part, the impacts of natural aging and the modified thermomechanical treatment on the strength and EC of the drawn Al–Mg–Si conductor alloys were studied. The natural aged samples is referred to those exposed to 70 °C for 10 h or 20 h followed by two weeks at room temperature. The modified thermomechanical treatment is referred to the pre-aging for 5 h at 180 °C before wire drawing. DSC results showed that natural aging had a negative influence on precipitation before the drawing process. However, wire drawing could neutralize the detrimental effect of natural aging on precipitation hardening. In other word, the naturally aged samples exhibited a higher strength above EC (52.5 %IACS) relative to those of the samples without natural aging. The TEM analysis revealed that the naturally aged samples had the higher precipitate number densities relative to those of the samples that were not exposed to natural aging. The strength model also showed the higher precipitate strengthening in the naturally aged samples relative to the samples without natural aging. The thermomechanical treatment was modified with applying the pre-aging (5h at 180 °C) before the wire drawing. Accordingly, the modified thermomechanical treatment led to the highest ultimate tensile strength (369 MPa) with a desirable EC (53% IACS) among all conditions. The strength and electrical resistivity models showed that the modified thermomechanical treatment resulted in a remarkably higher precipitate strengthening with a medium electrical resistivity. It was also found that strain hardening contribution reduced with the modified thermomechanical treatment. However, it revealed that the superior precipitate strengthening overcame the inferior strain hardening in the modified thermomechanical treatment. In the third part, the effects of Ag and Cu additions on strength and EC of Al-Mg-Si conductor alloys were studied under the conventional and modified thermomechanical treatment. Similar to the second part, the modified thermomechanical treatment is referred to a treatment in which pre-aging was applied to the samples before wire drawing. The Ag-/Cu-added alloys showed a slightly higher strength relative to the base alloy above EC (52.5 %IACS) under the conventional thermomechanical treatment. However, the modification of the thermomechanical treatment remarkably improved the strengthening effect of Ag and Cu additions above 52.5 %IACS. In addition, the modified thermomechanical treatment shortened the post-aging time to reach the minimum required EC (52.5 %IACS) compared to the conventional thermomechanical treatment (especially for Cu-added alloys). The strength model showed that modifying the thermomechanical treatment increased the precipitate hardening for the base alloy by 60%, although it deteriorated the strain hardening. The Ag and Cu additions further improved the precipitate hardening under the modified thermomechanical treatment. In spited of the reduced strain hardening, the precipitates are the promising factors to strengthen the materials under the modified thermomechanical treatment. The electrical resistivity model exhibited that precipitates gave rise to the medium electrical resistivity. For all parts of the project, the microstructural features were quantitively tailored to the mechanical strength and EC using the strengthening and electrical resistivity models.
L'exigence industrielle de faible densité, de haute résistance mécanique et de conductivité électrique (CE) a mené au développement d'alliages conducteurs Al-Mg-Si pour la ligne de transport d'énergie. Les précipités, les dislocations, les atomes de soluté et les joints de grains augmentent les résistances mécaniques des alliages conducteurs Al-Mg-Si. Cependant, ceux-ci augmentent résistivité électrique à cause des perturbations de la périodicité atomique dans une structure cristalline. En conséquence, les paramètres améliorant la résistance mécanique engendrent la résistivité électrique dans les alliages conducteurs Al-Mg-Si, montrant que la résistance mécanique et la conductivité électrique sont de comportement contradictoire. Par conséquent, l'amélioration simultanée de la résistance mécanique et la conductivité électrique représente un défi à relever. Dans cette étude, de meilleures combinaisons de résistances mécaniques et de CE dans les alliages conducteurs Al-Mg-Si ont été obtenues grâce à (a) des éléments d’alliage principaux optimaux (Mg et Si); b) le vieillissement naturel et la modification du traitement thermomécanique; c) des éléments d’alliage supplémentaires (Ag et Cu). Dans la première partie de cette étude, l'effet des différents rapports Mg/Si (2, 1.5, 1, 0.86) sur la résistance mécanique et la CE des alliages conducteurs Al-Mg-Si a été étudié. La valeur du Mg a été maintenue constante (0,65 % en masse) et les quantités de Si ont été modifiées. Il est constaté que la résistance mécanique maximale augmentait avec la diminution du rapport Mg/Si tandis que la CE correspondante diminuait. Par conséquent, un temps de vieillissement plus long a été nécessaire pour que les alliages ayant un rapport Mg/Si inférieur répondent au minimum requis en CE (52,5 % IACS). L'alliage avec un rapport Mg/Si de 0,86 a montré la résistance mécanique maximale la plus élevée parmi tous les alliages. Cependant, il était essentiel de prolonger le temps de vieillissement (>34 h) pour dépasser la CE (52,5 % IACS), ce qui entraînait une baisse significative de la résistance mécanique avec une marge étroite de résistances mécaniques et d'CE. L'alliage avec un rapport Mg/Si de ~ un a montré la résistance mécanique la plus élevée dans la gamme CE (52,5-54 % IACS). Le modèle de résistances mécaniques développé a montré qu’une résistance mécanique plus élevée de cet alliage pouvait correspondre aux contributions plus élevées du durcissement par précipité, du durcissement par l'écrouissage et du durcissement par solutés. Cependant, si la CE est la priorité, l'alliage avec un rapport Mg/Si de ~ 1,5 a montré un meilleur compromis entre la résistance mécanique et la CE à une CE élevée de (54-56 % IACS). Dans la deuxième partie, les impacts du vieillissement naturel et du traitement thermomécanique modifié sur la résistance mécanique et la CE des alliages conducteurs Al-Mg-Si étirés ont été étudiés. Les échantillons vieillis naturellement sont ceux exposés à 70 °C pendant 10 h ou 20 h suivis de deux semaines à température ambiante. Le traitement thermomécanique modifié est appelé pré-vieillissement pendant 5 h à 180 °C avant tréfilage. Les résultats du DSC ont montré que le vieillissement naturel avait une influence négative sur les précipitations avant le processus de tréfilage. Cependant, le tréfilage a pu neutraliser l'effet néfaste du vieillissement naturel sur le durcissement par précipitation après le tréfilage et le post-vieillissement. En d'autres mots, les échantillons naturellement vieillis présentaient une résistance mécanique plus élevée à une CE au dessus de (52.5 % IACS) par rapport à ceux des échantillons sans vieillissement naturel. L'analyse de la microscopie électronique en transmission (MET) a révélé que les échantillons naturellement vieillis avaient des densités numériques de précipités plus élevées par rapport à celles des échantillons qui n’étaient pas exposés au vieillissement naturel. Le modèle de résistances mécaniques a également montré un durcissement par précipité plus élevé dans les échantillons naturellement vieillis par rapport aux échantillons sans vieillissement naturel. Le traitement thermomécanique a été modifié par le pré-vieillissement (5h à 180 °C) avant le tréfilage. En conséquence, le traitement thermomécanique modifié a mené à la résistance mécanique la plus élevée (369 MPa) avec une CE acceptable (53% IACS) parmi toutes les conditions. Les modèles de résistances mécaniques et de résistivité électrique ont montré que le traitement thermomécanique modifié a mené à un durcissement par précipité remarquablement et plus élevé avec une résistivité électrique moyenne. Il a également été constaté que la contribution au durcissement par écrouissage diminuait avec le traitement thermomécanique modifié. Cependant, il s’est révélé que le durcissement par précipité était plus élevé et a surmonté le durcissement par écrouissage qui était moins élevé dans le traitement thermomécanique modifié. Dans la troisième partie, les effets des additions d'Ag et de Cu sur la résistance mécanique et la CE des alliages conducteurs Al-Mg-Si ont été étudiés par le traitement thermomécanique conventionnel et modifié. Semblable à la deuxième partie, le traitement thermomécanique modifié est référé à un traitement dans lequel le pré-vieillissement a été appliqué sur les échantillons avant le tréfilage. Les alliages avec Ag-/Cu ajoutés ont montré une résistance mécanique légèrement supérieure par rapport à l'alliage de base à une CE au dessus de (52,5 % IACS) sous le traitement thermomécanique conventionnel. Cependant, la modification du traitement thermomécanique a remarquablement amélioré l'effet de durcissement par ajout d'Ag et de Cu à une CE au-dessus de (52,5 % IACS). De plus, le traitement thermomécanique modifié a réduit le temps du vieillissement pour atteindre la CE minimale requise (52,5 % IACS) par rapport au traitement thermomécanique conventionnel (en particulier pour les alliages à Cu ajouté). Le modèle de résistance mécanique a montré que la modification du traitement thermomécanique augmentait le durcissement par précipité de l’alliage de base de 60%, bien qu’il ait détérioré le durcissement par écrouissage. Les ajouts d'Ag et de Cu ont encore amélioré le durcissement par précipité sous le traitement thermomécanique modifié. Malgré le durcissement par écrouissage réduit, les précipités sont les facteurs prometteurs pour faire durcir les matériaux sous le traitement thermomécanique modifié. Le modèle de résistivité électrique a montré que les précipités ont causé la résistivité électrique moyenne. Pour toutes les parties du projet, les caractéristiques microstructurelles ont été quantitativement adaptées à la résistance mécanique et à l'CE à l’aide des modèles de résistance mécanique et de résistivité électrique
The Toxicity of Synthetic and Biogenic Selenium Nanoparticles on Human Brain Glioblastoma Cell Line: An in vitro Comparison
Background: Brain tumors can be serious and life-threatening when they are treated effectively. Many therapeutic approaches, such as chemotherapy, radiotherapy, and surgery have been used to treat brain tumors. In this regard, selenium supplements have been reported effective.Methods: Selenium Nanoparticles (SeNPs) were produced in two forms of synthetic and biogenic to evaluate their cytotoxicity on brain glioblastoma cell lines. A-172 cell line was cultured in DMEM medium. The cytotoxicity of the synthetic and biogenic SeNP was assessed by MTT assay. Results: There was a significant difference between the group treated with biogenic and synthetic SeNP compared with non-treated cells after 24, 48, and 72 h. Both biogenic and synthetic SeNP increased Bax gene and decreased Bcl-2 gene expression. Conclusion: It seems that biogenic SeNP was more lethal than its synthetic form. Therefore, it should be considered that the method of NP construction may be an important parameter for its bioactivity
Photoactivation of Cell-Free Expressed Archaerhodopsin-3 in a Model Cell Membrane
Transmembrane receptor proteins are located in the plasma membranes of biological
cells where they exert important functions. Archaerhodopsin (Arch) proteins belong to a class
of transmembrane receptor proteins called photoreceptors that react to light. Although the light
sensitivity of proteins has been intensely investigated in recent decades, the electrophysiological
properties of pore-forming Archaerhodopsin (Arch), as studied in vitro, have remained largely
unknown. Here, we formed unsupported bilayers between two channels of a microfluidic chip
which enabled the simultaneous optical and electrical assessment of the bilayer in real time. Using a
cell-free expression system, we recombinantly produced a GFP (green fluorescent protein) labelled
as a variant of Arch-3. The label enabled us to follow the synthesis of Arch-3 and its incorporation
into the bilayer by fluorescence microscopy when excited by blue light. Applying a green laser for
excitation, we studied the electrophysiological properties of Arch-3 in the bilayer. The current signal
obtained during excitation revealed distinct steps upwards and downwards, which we interpreted as
the opening or closing of Arch-3 pores. From these steps, we estimated the pore radius to be 0.3 nm.
In the cell-free extract, proteins can be modified simply by changing the DNA. In the future, this
will enable us to study the photoelectrical properties of modified transmembrane protein constructs
with ease. Our work, thus, represents a first step in studying signaling cascades in conjunction with
coupled receptor proteins
The effects of sugars on the biofilm formation of Escherichia coli 185p on stainless steel and polyethylene terephthalate surfaces in a laboratory model
Background: Bacteria utilize various methods in order to live in protection from adverse environmental conditions. One such method involves biofilm formation; however, this formation is dependent on many factors. The type and concentration of substances such as sugars that are present in an environment can be effective facilitators of biofilm formation. Methods: First, the physico-chemical properties of the bacteria and the target surface were studied via the MATS and contact angle measurement methods. Additionally, adhesion to different surfaces in the presence of various concentrations of sugars was compared in order to evaluate the effect of these factors on the biofilm formation of Escherichia coli, which represents a major food contaminant. Results: Results showed that the presence of sugars has no effect on the bacterial growth rate; all three concentrations of sugars were hydrophilic and demonstrated a high affinity toward binding to the surfaces. Conclusions: The impact of sugars and other factors on biofilm formation can vary depending on the type of bacteria present. © 2016, Ahvaz Jundishapur University of Medical Sciences
Dietary intake of polyphenol and potassium in the management of Type 2 Diabetes Mellitus Subjects with Chronic Kidney Disease
Effects of natural aging and pre-aging on the strength and electrical conductivity in Al-Mg-Si AA6201 conductor alloys
The effects of natural aging (NA), and its combination with pre-aging (PA), on the strength and electrical conductivity (EC) of drawn Al–Mg–Si AA6201 conductor alloys were studied. Natural aging had a negative impact on precipitation before the drawing process. However, wire drawing counteracted the detrimental influence of natural aging on precipitation hardening; after drawing and post-aging, the NA samples exhibited a better combination of strength and EC compared to those of the samples that did not undergo NA. Transmission electron microscopy results show that the NA samples exhibited a higher number density of precipitates in the drawn and post-aged conditions relative to those of the samples that did not undergo NA. The combination of natural aging and pre-aging followed by wire drawing and post-aging provided the highest strength (369 MPa) with an acceptable EC (53% IACS). The applied natural aging and pre-aging modified the strengthening contributions in AA6201 conductor alloys in favor of precipitation hardening. The relationship between strength and EC was analyzed in detail using strengthening models and Matthiessen's rule based on various microstructural features
Effect of Ag and Cu addition on the strength and electrical conductivity of Al-Mg-Si alloys using conventional and modified thermomechanical treatments
The effect of adding Ag and Cu on the strength and electrical conductivity of Al-Mg-Si conductor alloys was investigated using conventional and modified thermomechanical treatments. In the conventional thermomechanical treatment, the addition of Ag and Cu moderately increased the strength from 296 MPa to 305–316 MPa above the minimum required electrical conductivity (52.5% IACS) compared to that of the base alloy. However, the modification of the thermomechanical treatment could maximize the efficiency of Ag and Cu addition at strengths above 52.5% IACS, exhibiting that the strength was increased from 317 MPa to 341–348 MPa with the Ag and Cu additions. All alloys under the modified thermomechanical treatment (MTMT) showed a superior strength and electrical conductivity compared to their counterparts under the conventional thermomechanical treatment (CTMT), resulting in a wider window in the high end of strength and electrical conductivity. In addition, MTMT led to a shorter post-aging time to reach the minimum required EC, compared to CTMT. The precipitate characteristics under both thermomechanical treatment conditions were analyzed and quantified using differential scanning calorimetry and transmission electron microscopy (TEM). The TEM results revealed that the alloys under MTMT had a higher precipitate number density by more than three times compared to their counterparts under CTMT, leading to the higher strength levels in the MTMT alloys. Strength and electrical resistivity models were then applied to understand the multiple contributions of the main strengthening mechanisms and microstructure features to the mechanical strength and electrical conductivity