22 research outputs found

    On proximal relations in transformation semigroups arising from generalized shifts

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    For a finite discrete topological space XX with at least two elements, a nonempty set Γ\Gamma, and a map φ:Γ→Γ\varphi:\Gamma\to\Gamma, σφ:XΓ→XΓ\sigma_\varphi:X^\Gamma\to X^\Gamma with σφ((xα)α∈Γ)=(xφ(α))α∈Γ\sigma_\varphi((x_\alpha)_{\alpha\in\Gamma})= (x_{\varphi(\alpha)})_{\alpha\in\Gamma} (for (xα)α∈Γ∈XΓ(x_\alpha)_{\alpha\in\Gamma}\in X^\Gamma) is a generalized shift. In this text for S={σψ:ψ∈ΓΓ}\mathcal{S}=\{\sigma_\psi:\psi\in\Gamma^\Gamma\} and H={σψ:Γ→ψΓ\mathcal{H}=\{\sigma_\psi: \Gamma\mathop{\rightarrow}\limits^{\psi}\Gamma is bijective}\} we study proximal relations of transformation semigroups (S,XΓ)(\mathcal{S},X^\Gamma) and (H,XΓ)(\mathcal{H},X^\Gamma). Regarding proximal relation we prove: P(S,XΓ)={((xα)α∈Γ,(yα)α∈Γ)∈XΓ×XΓ:∃β∈Γ (xβ=yβ)}P({\mathcal S},X^\Gamma)=\{((x_\alpha)_{\alpha\in\Gamma},(y_\alpha)_{\alpha\in\Gamma}) \in X^\Gamma\times X^\Gamma: \exists\beta\in\Gamma\:(x_\beta=y_\beta)\} and P(H,XΓ)⊆{((xα)α∈Γ,(yα)α∈Γ)∈XΓ×XΓ:{β∈Γ:xβ=yβ}P({\mathcal H},X^\Gamma)\subseteq \{((x_\alpha)_{\alpha\in\Gamma},(y_\alpha)_{\alpha\in\Gamma}) \in X^\Gamma\times X^\Gamma: \{\beta\in\Gamma:x_\beta=y_\beta\} is infinite~}∪{(x,x):x∈X}\}\cup\{ (x,x):x\in \mathcal{X}\}. \\ Moreover, for infinite Γ\Gamma, both transformation semigroups (S,XΓ)({\mathcal S},X^\Gamma) and (H,XΓ)({\mathcal H},X^\Gamma) are regionally proximal, i.e., Q(S,XΓ)=Q(H,XΓ)=XΓ×XΓQ({\mathcal S},X^\Gamma)=Q({\mathcal H},X^\Gamma)=X^\Gamma \times X^\Gamma, also for sydetically proximal relation we have L(H,XΓ)={((xα)α∈Γ,(yα)α∈Γ)∈XΓ×XΓ:{γ∈Γ:xγ≠yγ}L({\mathcal H},X^\Gamma)=\{((x_\alpha)_{\alpha\in\Gamma},(y_\alpha)_{\alpha\in\Gamma}) \in X^\Gamma\times X^\Gamma: \{\gamma\in\Gamma:x_\gamma\neq y_\gamma\} is finite}\}.Comment: 8 page

    Effect of low-temperature precipitates on microstructure and pseudoelasticity of an Fe–Mn–Si-based shape memory alloy

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    Fe–Mn–Si-based shape memory alloys (Fe-SMAs) have attracted much research attention due to their potential applications for vibration mitigation, energy dissipation, and re-centering in the construction sector. Because of the crucial impact of precipitation on the pseudoelasticity (PE) behavior of Fe-SMAs, the equilibrium phase diagram of an Fe–17Mn–5Si–10Cr–4Ni–1(V-C) (wt%) SMA was used in this study to identify a low-temperature precipitate and study its effect on the microstructure and PE of the alloy after a low-temperature aging process. Transmission electron microscopy (TEM) studies revealed that aging at 485 °C for 6 h after aging at 750 °C for 6 h led to the precipitation of fresh, parallelogram-shaped, (Cr–V–C)-rich precipitates along with elliptical-shaped, V-rich precipitates in the austenite grains of the recrystallized samples. Numerous parallel stacking faults (SFs) were formed due to the presence of the precipitates within the austenite grains. It is postulated that such an arrangement of SFs can further improve the PE by reducing the activation energy for the nucleation of ɛ-martensite laths and inhibiting them from colliding with each other and consequent formation of α'-martensite, resulting in a residual strain reduction to 2.7% after 4.0% tensile straining

    Changes in Aflatoxin Content During the Processing of Vinegar Obtained From Grape

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    Mycotoxins are known to be one of the most important food contaminants that pose potential health risks to humans. This study aimed to investigate the changes in total aflatoxin (TAF) content during grape vinegar production. Different types of aflatoxins including aflatoxin B1 (AFB1 ), B2 (AFB2 ), G1 (AFG1 ), and G2 (AFG2 ) were spiked into washed grape samples in the level of 5 μg/kg. Then grape samples were converted to vinegar. After different stages of vinegar processing including juicing, alcoholic fermentation, acetic acid fermentation, and pasteurization, sampling was performed and the level of each aflatoxin was measured using high performance liquid chromatography with fluorescence detector (HPLC-FD). Among different processing steps, the pasteurization operation had the least effect on the removal of aflatoxin. After juicing, the amount of AFB1 , AFB2 , AFG1 and AFG2 decreased by 14%, 11.18%, 13.77%, and 18.56%, respectively. Alcoholic fermentation had the greatest effect on the removal of aflatoxin so that it could reduce the levels of AFB1 , AFB2 , AFG1 and AFG2 by 41.87%, 45.34%, 45.37%, and 46.52%, respectively. Overall, during processing and conversion of grapes to vinegar, the values of AFB1 , AFB2 , AFG1 and AFG2 were reduced by 76.20%, 71.06%, 69.26%, and 75.85%, respectively. Processing grapes to vinegar can have a significant effect on the aflatoxin reduction

    Alteration of hepatocellular antioxidant gene expression pattern and biomarkers of oxidative damage in diazinon-induced acute toxicity in Wistar rat

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    In the present survey, the plasma level of diazinon after acute exposure was measured by HPLC method at a time-course manner. In addition, the impact of diazinon on the expression of the key genes responsible for hepatocellular antioxidative defense, including PON1, GPx and CAT were investigated. The increase in oxidative damages in treated rats was determined by measuring LPO, protein carbonyl content and total antioxidant power in plasma. After administration of 85 mg/kg diazinon in ten groups of male Wistar rats at different time points between 0-24 hours, the activity of AChE enzyme was inhibited to about 77.94 %. Significant increases in carbonyl groups and LPO after 0.75 and 1 hours were also observed while the plasma antioxidant power was significantly decreased. Despite the dramatic reduction of GPX and PON1 gene expression, CAT gene was significantly upregulated in mRNA level by 1.1 fold after 4 hours and 1.5-fold after 24 hours due to diazinon exposure, compared to control group. Furthermore, no significant changes in diazinon plasma levels were found after 4 hours in the treated rats. The limits of detection and quantification were 137.42 and 416.52 ng/mL, respectively. The average percentage recoveries from plasma were between 90.62 % and 95.72 %. In conclusion, acute exposure to diazinon increased oxidative stress markers in a time-dependent manner and the changes were consistent with effects on hepatic antioxidant gene expression pattern. The effect of diazinon even as a non-lethal dose was induced on the gene expression of antioxidant enzymes. The change in antioxidant defense system occurs prior to diazinon plasma peak time. These results provide biochemical and molecular evidence supporting potential acute toxicity of diazinon and is beneficial in the evaluation of acute toxicity of other organophosphorus pesticides as well

    Biochemical and Histological Evidence on the Protective Effects of Allium hirtifolium Boiss (Persian Shallot) as an Herbal Supplement in Cadmium-Induced Hepatotoxicity

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    Background and Objectives. Allium hirtifolium Boiss (Persian shallot), as an edible vegetable, has several pharmacological properties including antimicrobial, anti-inflammatory, and antioxidative effects, while its protective effects in liver cells are controversial. In this study, we examined the effect of A. hirtifolium extract on cadmium- (Cd-) induced hepatotoxicity in rats. Materials and Methods. Thirty-six male Wistar rats were divided into six groups: groups 1, 2, and 3 received vehicle, Cd (100 mg/L/day by drinking water), and A. hirtifolium extract (200 mg/kg/day; orally), respectively. Groups 4, 5, and 6 were Cd groups which were treated with A. hirtifolium extract (50, 100, and 200 mg/kg/day, respectively). After 2 weeks, liver enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) and also oxidative stress biomarkers including lipid peroxidation (LPO), total antioxidant capacity (TAC), total thiol molecule (TTM), and the histopathological changes were determined using standard procedure. Results. The findings showed that Cd caused a remarkable rise in levels of serum hepatic enzymes such as ALT (P<0.001), AST (P<0.01) and ALP (P<0.001) compared with the control group. In addition, Cd led to the decreasing of the levels of TTM (P<0.001) and TAC (P<0.001) and increasing of LPO (P<0.001) in liver tissue in comparison with the control group. In this regard, remarkable vascular congestion, hepatocellular degeneration, and vacuolization were observed in hepatic tissue of Cd-treated rats. Following the administration of A. hirtifolium extract, a significant improvement was observed in the functional and oxidative stress indices of hepatic tissue alongside histopathologic changes. Conclusion. The current study indicated that the A. hirtifolium extract might prevent hepatic oxidative injury by improving oxidant/antioxidant balance in rats exposed to Cd

    Effect of storage, washing, and cooking on the stability of five pesticides in edible fungi of Agaricus bisporus: A degradation kinetic study

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    Pesticide residue in food products is one of the most important global health challenges. The current study sought to investigate the changes in pesticides residue levels in Agaricus bisporus under different storage conditions and during washing and cooking. Pesticides analysis was performed using gas chromatography/mass spectrometry (GC-MS). The results showed that the half-life (t1/2) of all of the studied pesticides stored at room temperature was lower than refrigerator and freezer temperature. In addition, the greatest reduction of diazinon, malathion, permethrin, propargite, and fenpropathrin was found at a pH of 12, 2, 12, 7, and 9, respectively. Although sodium chloride had no effective impact on pesticide reduction during the same washing times, the removal of pesticides increased as washing time increased. Further, the reduction of pesticides was time-dependent during the boiling, microwaving, and frying processes. Based on these findings, the stability of insecticides, such as permethrin, malathion, and diazinon, was lower than acaricides, including propargite and fenpropathrin, in various techniques. Therefore, the use of washing solutions with an appropriate pH as well as increased cooking time may reduce the risk of pesticide exposure

    Stachys lavandulifolia Causing Estrogen/Progesterone Imbalance during Pregnancy in Wistar Rat: A Time Course Experimental Study: Stachys Lavandulifolia induces abortion in rat

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    Stachys lavandulifolia is one of the most abortive herbs used in Iran. The present study aimed to investigate the effects of different doses of hydroalcoholic extract of Stachys lavandulifolia (HAESL) on serum estrogen and progesterone levels during different stages (implantation, abortion, and parturition) of pregnancy in Wistar rats. After observing vaginal plaque, the pregnant rats were randomly divided into three studied groups. Each group received the HAESL for three periods including, implantation (days 3 to 5), abortion (days 10 to 12), and parturition (days 19 to 21) of pregnancy. In the abortion and parturition periods, we observed a significant decrease in the estrogen level following administration of HAESL (300 and 900 mg/kg). In addition, we observed a significant decrease in the progesterone level at the highest dose of HAESL in all stages of pregnancy. In conclusion, the present study suggests that Stachys lavandulifolia may affect the estrogen/progesterone levels due to the presence of flavonoid compounds that subsequently lead to abortion, especially during the abortion and parturition periods

    The Cytotoxic Effect of Thymoquinone Enhance on HepG2 Cell Line due to Induction of Fenton Reaction by Hydrogen Peroxide: An In Vitro and In Silico Study

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    Thymoquinone (TQ) is a component derived from the volatile oil of Nigella sativa. Fenton reaction induction is a well-known strategy to prevent the growth of cancer cells which can stimulate by hydrogen peroxide. This study was designed to investigate the TQ effects on hydrogen peroxide-induced cytotoxicity. Methods: In this study, HepG2 cell survival, reactive oxygen species (ROS) production, cell membrane integrity, and changes of superoxide dismutase (SOD)/ catalase (CAT) activity were evaluated following incubation of HepG2 cells with 31 μM hydrogen peroxide and different concentrations of TQ (18.5, 37 and 75 μM). In addition, molecular docking studies on the interference of TQ with CAT/SOD enzymes were investigated. Results: Our findings showed that TQ low concentration can increase the survival of HepG2 cells when exposed to hydrogen peroxide, and on the contrary, its high concentration can potentiate cytotoxicity induced by hydrogen peroxide. The TQ alongside hydrogen peroxide increased the production of ROS, which was related to increase CAT and SOD activity in the HepG2 cells. Molecular docking findings showed that TQ effects on the formation of free radicals were not related to its chemical interference with the structure of the SOD/CAT molecules. Conclusion: Fenton reaction induction may increase the effectiveness of TQ in preventing HepG2 cells proliferation
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