677 research outputs found

    Initial Characterized L-spaces and Characterized L- topological Groups

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    In this research work, new topological notions are proposed and investigated. The notions are named initial characterized L-spaces and characterized L-topological groups. The properties of such notions are deeply studied. We show that the intitial characterized L-space for an characterized L-spaces exists. By this notion, the notions of characterized L-subspace and characterized product L-space are introduced and studied. More information can be found in the full paper

    On Initial and Final Characterized L- topological Groups

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    In this research work, new topological notions are proposed and investigated. The notions are named finalcharacterized L-spaces and initial and final characterized L-topological groups. The properties of such notionsare deeply studied. We show that all the final lefts and all the final characterized L-spaces are uniquely exist inthe category CRL-Sp and hence CRL-Sp is topological category over the category SET of all sets. By the notion offinal characterized L-space, the notions of characterized qoutien pre L-spaces and characterized sum L-spacesare introduced and studied. The characterized L-subspaces together with their related inclusion mappings andthe characterized quotient pre L-spaces together with their related canonical surjections are the equalizers andco-equalizers, respectively in CRL-Sp. Moreover, we show that the initial and final lefts and then the initial andfinal characterized L-topological groups uniquely exist in the category CRL-TopGrp. Hence, the category CRLTopGrpis topological category over the category Grp of all groups. By the notion of initial and finalcharacterized L-topological groups, the notions of characterized L-subgroups, characterized product Ltopologicalgroups and characterized L-topological quotient groups are introduced and studied., we show that thecategory CRL-TopGrp is concrete and co-concrete category of the category L-Top. More details can be found in the full paper

    OPTIMAL DISTRIBUTED CONTROL OF STOCHASTIC ELLIPTIC SYSTEMS WITH CONSTRAINTS

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    The objective of this paper is to study the optimality for stochastic non cooperative elliptic systems. A distributed control problem for a stochastic elliptic systems with constraints on states and controls is studied. First, the existence and uniqueness of the state process for these systems are proved. The necessary and sufficient conditions of optimality are derived for the Dirichlet and Neumann problems

    Electrochemical Performance of Grids of Lead-acid Batteries made from Pb-0.8%Ca-1.1%Sn Alloys Containing Cu, As and Sb Impurities in the presence of phosphoric acid

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    Electrochemical performance of grids of lead-acid Batteries manufactured from Pb-0.8%Ca-1.1%Sn alloys containing Cu, As and Sb impurities at 0.1 wt% level were studied in 4.0 M H2SO4 without and with 0.4 M H3PO4. The presence of impurities in the alloy or addition of H3PO4 was found to suppress the corrosion rate. H3PO4 increased the rates of both hydrogen and oxygen evolution reactions at high overpotentials for all alloys. Except for Cu-containing alloy, H3PO4 had a slight positive effect on PbO2 formation.The self-discharge of PbO2 under polarization or opencircuitconditions increased in the presence of H3PO4 but the positive grid corrosion decreased, except for the As-containing alloy. Impurity-containing alloys showed significantly lower self-discharge rate in the presence of H3PO4 than in its absence. Impedance measurement was able to detect and quantify the formation of the highly insulating inner PbO layer beneath the outer PbSO4 layer and its transformation to the conducting PbO2, during the oxidation of alloys under constant current conditions.H3PO4 significantly enhanced the formation of PbO in thepresence of impurities, especially Sb

    Amelioration of The Dielectric Properties of Ceramic Insulators Using Nano-alumina

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    Outdoor HV porcelain insulators face various environmental stresses that cause their degradation. Consequently, amelioration of their insulating properties becomes a target of recent researches to survive higher voltage levels. Investigating the impact of the addition of 0, 5, 10, and 15 wt. % nano- alumina (NA) on the dielectric and physical characteristics of porcelain materials at elevated sintering temperatures is the aim of this study. Porcelain specimens were synthesized from kaolin, feldspar, and quartz as available low-cost raw materials. The specimens were sintered at 1100, 1200, 1300, and 1400°C for 2 h. For some specimens, the microstructure and phases formed were identified using scanning electron microscopy and X-ray diffraction techniques. The changes that occur upon heating (include melting, phase transition, sublimation, and decomposition) were identified by Differential Thermogravimetric Analysis. The dielectric strength, relative permittivity, and loss tangent of different samples were measured at a large scale of frequencies. Breakdown strength values of different samples were verified by applying the Finite Element Method. The best electrical and physical properties were achieved at 1300ºC. At this temperature the porcelain sample containing 5 wt. % NA presented optimum physical characteristics as well as good insulating properties assent the feasibility of producing electro-technical porcelai

    Sildenafil citrate for the management of asymmetrical intrauterine growth restriction and its effect on umbilical artery Doppler

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    Background: Asymmetrical intrauterine growth restriction IUGR occurs when there is uteroplacental insufficiency. Sildenafil citrate phosphodiasterase-5 inhibito is a potent vasodilator, which selectively inhibits phosphodiesterase-5 and, as a consequence, enhances the action of cyclic guanosine monophosphate which is the second messenger of NO. Hence, the trial was used for improving uteroplacental perfusion through enhancing vasodilatation of myometrial small arteries boosting flow within uteroplacental bed. The aim was to evaluate the efficacy of adding sildenafil citrate to low dose aspirin in treatment of asymmetrical IUGR through its effect on uteroplacental blood flow guided by Doppler ultrasound.Methods: Our study was a prospective double-blinded, randomized, controlled trial. Recruitment of participating women was from the obstetric outpatient clinic of Aswan university hospital. 100 patients included in the study and randomized in two groups. The first group was 50 patients assigned sildenafil with low dose aspirin and the second group was 50 patients assigned placebo with low dose aspirin.Results: As regard the outcomes, the study demonstrated that using of SC and LDA were effective in increasing estimated fetal weight and in improvement of umbilical artery umbilical artery Doppler (UAD) indices RI and PI for pregnancy complicated with IUGR compared with the control group.Conclusions: Sildenafil citrate is a promising treatment for IUGR fetuses with prolongation of pregnancy and improvement of fetal birth weight, umblical Doppler indices UDI, decreases days needed in PCU

    Camel Milk Triggers Apoptotic Signaling Pathways in Human Hepatoma HepG2 and Breast Cancer MCF7 Cell Lines through Transcriptional Mechanism

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    Few published studies have reported the use of crude camel milk in the treatment of stomach infections, tuberculosis and cancer. Yet, little research was conducted on the effect of camel milk on the apoptosis and oxidative stress associated with human cancer. The present study investigated the effect and the underlying mechanisms of camel milk on the proliferation of human cancer cells using an in vitro model of human hepatoma (HepG2) and human breast (MCF7) cancer cells. Our results showed that camel milk, but not bovine milk, significantly inhibited HepG2 and MCF7 cells proliferation through the activation of caspase-3 mRNA and activity levels, and the induction of death receptors in both cell lines. In addition, Camel milk enhanced the expression of oxidative stress markers, heme oxygenase-1 and reactive oxygen species production in both cells. Mechanistically, the increase in caspase-3 mRNA levels by camel milk was completely blocked by the transcriptional inhibitor, actinomycin D; implying that camel milk increased de novo RNA synthesis. Furthermore, Inhibition of the mitogen activated protein kinases differentially modulated the camel milk-induced caspase-3 mRNA levels. Taken together, camel milk inhibited HepG2 and MCF7 cells survival and proliferation through the activation of both the extrinsic and intrinsic apoptotic pathways

    On a novel hybrid Manta ray foraging optimizer and its application on parameters estimation of lithium-ion battery

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    In this paper, we propose a hybrid meta-heuristic algorithm called MRFO-PSO that hybridizes the Manta ray foraging optimization (MRFO) and particle swarm optimization (PSO) with the aim to balance the exploration and exploitation abilities. In the MRFO-PSO, the concept of velocity of the PSO is incorporated to guide the searching process of the MRFO, where the velocity is updated by the first best and the second-best solutions. By this integration, the balancing issue between the exploration phase and exploitation ability has been further improved. To illustrate the robustness and effectiveness of the MRFO-PSO, it is tested on 23 benchmark equations and it is applied to estimate the parameters of Tremblay's model with three different commercial lithium-ion batteries including the Samsung Cylindrical ICR18650-22 lithium-ion rechargeable battery, Tenergy 30209 prismatic cell, Ultralife UBBL03 (type LI-7) rechargeable battery. The study contribution exclusively utilizes hybrid machine learning-based tuning for Tremblay's model parameters to overcome the disadvantages of human-based tuning. In addition, the comparisons of the MRFO-PSO with six recent meta-heuristic methods are performed in terms of some statistical metrics and Wilcoxon's test-based non-parametric test. As a result, the conducted performance measures have confirmed the competitive results as well as the superiority of the proposed MRFO-PSO.Web of Science151art. no. 6

    Pro-inflammatory and oxidative stress pathways which compromise sperm motility and survival may be altered by L-carnitine

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    The testis is an immunologically privileged organ. Sertoli cells can form a blood-testis barrier and protect sperm cells from self-immune system attacks. Spermatogenesis may be inhibited by severe illness, bacterial infections and chronic inflammatory diseases but the mechanism(s) is poorly understood. Our objective is to help in understanding such mechanism(s) to develop protective agents against temporary or permanent testicular dysfunction. Lipopolysaccaride (LPS) is used as a model of animal sepsis while L-carnitine (LCR) is used as a protective agent. A total of 60 male Swiss albino rats were divided into four groups (15/group). The control group received Saline; the 2nd group was given LCR (500 mg/kg i.p, once). The third group was treated with LPS (5 mg/kg i.p once) and the fourth group received LCR then LPS after three hours. From each group, five rats were used for histopathological examination. Biochemical parameters were assessed in the remaining ten rats. At the end of the experiment, animals were lightly anaesthetized with ether where blood samples were collected and testes were dissected on ice. Sperm count and motility were evaluated from cauda epididymis in each animal. Also, oxidative stress was evaluated by measuring testicular contents of reduced glutathione (GSH), malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-HDG, the DNA adduct for oxidative damage) in testicular DNA. The pro-inflammatory mediator nitric oxide (NO) in addition to lactate dehydrogenase (LDHx) isoenzyme-x activity as an indicator for normal spermatozoal metabolism were assessed in testicular homogenate. Serum interlukin (IL)-2 level was also assessed as a marker for T-helper cell function. The obtained data revealed that LPS induced marked reductions in sperm's count and motility, obstruction in seminiferous tubules, hypospermia and dilated congested blood vessels in testicular sections concomitant with decreased testicular GSH content and LDHx activity. Moreover, the testicular levels of MDA, 8-HDG (in testicular DNA) and NO as well as serum IL-2 level were increased. Administration of LCR before LPS returned both sperm count and motility to normal levels. Also, contents of testicular GSH, MDA, 8-HDG and NO returned back to the corresponding control values. In addition, serum IL-2 level as well as histological abnormalities were markedly improved in LCR + LPS-treated rats. In conclusion, LPS increased proinflammatory and oxidative stress markers in the testis leading to a marked testicular dysfunction. L-carnitine administration ameliorates these effects by antioxidant and/or anti-inflammatory mechanisms suggesting a protective role against male infertility in severely infected or septic patients

    Acacia senegal gum exudate offers protection against cyclophosphamide-induced urinary bladder cytotoxicity

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    Cylophosphamide (CYCL) is a strong anticancer and immunosuppressive agent but its urotoxicity presents one of the major toxic effects that limit its wide usage particularly in high dose regimens. Therefore, this study aimed to investigate Acacia Senegal gum exudate, Gum Arabic (GA), for its possible role as a natural, nontoxic agent against CYCL-induced urotoxicity. Male Swiss albino rats were exposed to CYCL (150 mg/kg BW, once i.p) with or without GA oral supplementation (7.5 g/kg/day for 6 days) through drinking water. Glutathione (GSH), Malondialdehyde (MDA) and Nitric oxide (NO) bladder contents were assessed. Responsiveness of the bladder rings to acetylcholine (ACh) in vitro, microscopic and macroscopic features are also investigated. CYCL produced pronounced harmful effects on bladder urothelial lining with significant increases in (MDA) and NO levels in the tissue homogenates. Bladder-GSH content is dropped by over 60% following CYCL injection. Bladder contractility, as measured by its responsiveness to ACh, recorded a marked reduction. The isolated bladders exhibited such macroscopic changes as severe edema, inflammation and extravasation. The bladder weight increased as well. Histological changes were evident in the form of severe congestion, petechial hemorrhage and chronic inflammatory reaction in the lamina propria accompanied with desquamated epithelia. GA, a potential protective agent, produced an almost complete reversal of NO induction, lipid peroxidation or cellular GSH bladder contents in the GA + CYCL-treated group. Likewise, bladder inflammation and edema were reduced. Bladder rings showed a remarkable recovery in their responsiveness to ACh. Bladder histological examination showed a near normal configuration and structural integrity, with a significant reduction in inflammation and disappearance of focal erosions. These remarkable effects of GA may be attributed to its ability to neutralize acrolein, the reactive metabolite of CYCL and/or the resultant reactive oxygen metabolites, through a scavenging action. GA may limit the cascading events of CYCL-induced damage, initiating a cytoprotective effect leading to structural and functional recovery of the bladder tissues
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