Immunohistochemical Analysis of Citrulline-Nitric Oxide Cycle Enzymes and Glutamine Synthetase in Different Regions of Brain in Epilepsy Rat Model

The aim of this study was to determine the immunoreactivity of neuronal and inducible nitric oxide synthetase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase in different regions of brain in rats of kainic acid mediated epilepsy. Male Sprague-Dawley rats were used in this study. The acute group animals were sacrificed after 2 hours and the chronic group animals were sacrificed after 5 days of a single subcutaneous injection of kainic acid (15 mg/kg body weight). The cerebral cortex, cerebellum and brain stem slices were fixed and immunohistostained for the above enzymes. Images were captured and analyzed. In acute group, argininosuccinate synthetase and inducible nitric oxide synthetase were increased in cerebral cortex and cerebellum, neuronal nitric oxide synthetase increased in cerebral cortex and brain stem, and there was no change in argininosuccinate lyase immunoreactivity compared to control group. In chronic group, glutamine synthetase was decreased and all other enzymes immunoreactivity was increased in all the brain regions tested. This study demonstrated the up-regulation of citrul-line-nitric oxide cycle enzymes and may contribute to enhancing recycling of citrulline to arginine to support the increased production of nitric oxide in epilepsy. The decreased glutamine synthetase may increase glutamate in chronic epilepsy and may lead to neurodegeneration.

Cycling performance of layered oxide cathode materials for sodium-ion batteries

Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.

Highly-efficient and autocatalytic reduction of NaHCO_3 into formate by in situ hydrogen from water splitting with metal/metal oxide redox cycle

The Earth’s sustainable development is threatened by the increasing atmospheric COlevel which can be attributed to the imbalance of COdue to the rapid consumption of fossil fuels caused by human activities and the slow absorption and conversion of COby nature. One of the efficient methods for reconstructing the balance of COshould involve the rapid conversion of COinto fuels and chemicals.The hydrogenation of COwith gaseous hydrogen is currently considered to be the most commercially feasible synthetic route, however, the supply of safe and economical hydrogen sources poses a significant challenge to up-scaling application. Direct utilization of hydrogen from dissociation of water, the most abundant, cheap and clean hydrogen resource, for the reduction of COwould be one of the most promising approaches for COutilization. This paper provides an overview of the current advances in research on highly efficient reduction of COor NaHCO, a representative compound of CO, into formic acid/formate by in situ hydrogen from water dissociation with a metal/metal oxide redox cycle under mild hydrothermal conditions.

Endothelial nitric oxide synthase deficiency influences normal cell cycle progression and apoptosis in trabecular meshwork cells

AIM： To clarify how the endothelial nitric oxide synthase （eNOS, NOS3） make effect on outflow facility through the trabecular meshwork （TM）. METHODS： Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control （NC） cells were determined, still were the collagen, type IV, alpha 1 （COL4A1） and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS： The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION： Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component （e.g. fibronectin 1 and COL4A1）. Reduced NOS3 restrains the TM cell cycle progression at the G2/ M-phase transition and induced cell apoptosis.

Exploitation of Waste Heat from a Solid Oxide Fuel Cell via an Alkali Metal Thermoelectric Converter and Electrochemical Cycles

In order to employ the waste heat effectively,a novel three-stage integrated system based upon a solid oxide fuel cell(SOFC),an alkali metal thermoelectric converter(AMTEC)and thermally regenerative electrochemical cycles(TRECs)is put forward.Considering the main electrochemically and thermodynamically irreversible losses,the power output and the efficiency of the subsystems and the integrated system are compared,and optimally operating regions for the current density,the power output,and the efficiency of the integrated system are explored.Calculations demonstrate that the maximum power density of the considered system is up to 7466 W/m2,which allows 18%and 74%higher than that of the conventional SOFC-AMTEC device and the stand-alone fuel cell model,respectively.It is proved that the considered system is an efficient approach to boost energy efficiency.Moreover,the influence of several significant parameters on the comprehensive performance of the integrated system is expounded in detail,including the electrolyte thickness of the SOFC,the leakage resistance of the SOFC,and the area ratio between the SOFC electrode and the AMTEC subsystem.

Regulating the electrochemical activity of Fe-Mn-Cu-based layer oxides as cathode materials for high-performance Na-ion battery

Fe-Mn based layer oxides cathode materials have attracted widespread attention as a potential candidate for sodium-ion batteries(SIBs)owing to the earth abundance,cost-effectiveness and acceptable specific capacity.However,the irreversible phase transition often brings rapid capacity decay,which seriously hinders the practical application in large-scale energy storage.Herein,we design a nickel-doped Na_(0.70)Fe_(0.10)Cu_(0.20)Ni_(0.05)Mn_(0.65)O_(2)(NFCNM-0.05)cathode material of SIBs with activated anionic redox reaction,and then inhibit the harmful phase transition.The ex-situ X-ray diffraction patterns demonstrate the NFCNM-0.05 always keeps the P2 phase during the sodiation/desodiation process,indicating a high structure stability.The ex-situ X-ray photoelectron spectroscopy implies the redox reactions between O2-and O-occur in the charging process,which offers extra specific capacity.Thus,the NFCNM-0.05 electrode delivers a high initial discharge capacity of 148 mA h g-1and remains a prominent cycling stability with an excellent capacity retention of 95.9%after 200 cycles at 1 C.In addition,the electrochemical impedance spectroscopy and galvanostatic intermittent titration technique show the NFCNM-0.05 electrode possesses fast ion diffusion ability,which is beneficial for the enhancement of rate performance.Even at 10 C,the NFCNM-0.05 can offer a reversible discharge capacity of 81 mA h g-1.DFT calculation demonstrates the doping of appropriate amount of Ni ions is benefit for the enhancement of the electrochemical performance of the layer oxides.This work provides an effective strategy to enhance the electrochemical performance of Fe-Mn based cathode materials of SIBs.

Cdk5 and aberrant cell cycle activation at the core of neurodegeneration

Neurodegenerative diseases are caused by the progressive loss of specific neurons.The exact mechanisms of action of these diseases are unknown,and many studies have focused on pathways related to abnormal accumulation and processing of proteins,mitochondrial dysfunction,and oxidative stress leading to apoptotic death.However,a growing body of evidence indicates that aberrant cell cycle re-entry plays a major role in the pathogenesis of neurodegeneration.The activation of the cell cycle in mature neurons could be promoted by several signaling mechanisms,including c-Jun N-terminal kinases,p38 mitogen-activated protein kinases,and mitogen-activated protein kinase/extracellular signal-regulated kinase cascades;post-translational modifications such as Tau-phosphorylation;and DNA damage response.In all these events,implicated Cdk5,a proline-directed serine/threonine protein kinase,seems to be responsible for several cellular processes in neurons including axon growth,neurotransmission,synaptic plasticity,neuronal migration,and maintenance of neuronal survival.However,under pathological conditions,Cdk5 dysregulation may lead to cell cycle re-entry in post-mitotic neurons.Thus,Cdk5 hyperactivation,by its physiologic activator p25,hyper-phosphorylates downstream substrates related to neurodegenerative diseases.This review summarizes factors such as oxidative stress,DNA damage response,signaling pathway disturbance,and Ubiquitin proteasome malfunction contributing to cell cycle re-entry in post-mitotic neurons.It also describes how all these factors are linked to a greater or lesser extent with Cdk5.Thus,it offers a global vision of the function of cell cycle-related proteins in mature neurons with a focus on Cdk5 and how this protein contributes to the development of Alzheimer’s disease,Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease by cell cycle activation.

The Paleoproterozoic and Neoproterozoic Carbon Cycle Promoted the Evolution of a Habitable Earth

The carbon cycle is an important process that regulates Earth's evolution.We compare two typical periods,in the Paleoproterozoic and Neoproterozoic,in which many geological events occurred.It remains an open question when modern plate tectonics started on Earth and how it has influenced the carbon cycle through time.In the Paleoproterozoic,intense weathering in a highly CO_(2)and CH_(4)rich atmosphere caused more nutritional elements to be carried into the ocean.Terrestrial input boosted high biological productivity,deposition of sediments and the formation of an altered oceanic crust,which may have promoted an increase in the oxygen content.Sediment lubrication and a decrease in mantle potential temperature made cold and deep subduction possible,which carried more carbon into the deep mantle.Carbon can be stored in the mantle as diamond and carbonated mantle rocks,being released by arc and mid-ocean ridge outgassing at widely different times.From the Paleoproterozoic through the Neoproterozoic to the Phanerozoic,the carbon cycle has promoted the evolution of a habitable Earth.

Study on metal recovery process and kinetics of oxidative leaching from spent LiFePO_(4)Li-batteries

A green environmental protection and enhanced leaching process was proposed to recover all elements from spent lithium iron phosphate(LiFePO_(4)) lithium batteries.In order to reduce the influence of Al impurity in the recovery process,NaOH was used to remove impurity.After impurity removal,the spent LiFePO_(4) cathode material was used as raw material under the H_(2)SO_(4) system,and the pressure oxidation leaching process was adopted to achieve the preferential leaching of lithium.The E-pH diagram of the Fe-P-Al-H_(2)O system can determine the stable region of each element in the recovery process of spent LiFePO_(4)Li-batteries.Under the optimal conditions(500 r·min^(-1),15 h,363.15 K,0.4 MPa,the liquid-solid ratio was 4:1 ml·g^(-1)and the acid-material ratio was 0.29),the leaching rate of Li was 99.24%,Fe,Al,and Ti were 0.10%,2.07%,and 0.03%,respectively.The Fe and P were precipitated and recovered as FePO_(4)·2H_(2)O.The kinetic analysis shows that the process of high-pressure acid leaching of spent LiFePO_(4) materials depends on the surface chemical reaction.Through the life cycle assessment(LCA)of the spent LiFePO_(4) whole recovery process,eight midpoint impact categories were selected to assess the impact of recovery process.The results can provide basic environmental information on production process for recycling industry.

Influence of prior cyclic oxidation on high temperature low cycle fatigue life of bare and Pt-Al coated superalloy Rene®80

The prediction of fatigue life of metallic alloys is justly accepted as one of the most important phenomena in the field of metallurgical and mechanical engineering.At elevated temperatures,oxidation of the surfaces has an effective role in the fatigue strength and ductility of the alloys.In the present work,the effect of prior cyclic oxidation on the high temperature low cycle fatigue(HTLCF)properties of nickel-based superalloy Rene®80 has been assessed in the uncoated state and in the Pt-aluminide(Pt-Al)coated condition at 930℃.To apply cyclic oxidation,simulation of engine thermal exposure was carried out by exposing coated and uncoated fatigue specimens in the burner rig(120 cycles at 1100℃).The cyclic oxidation procedure led to a changing in the coating microstructure from the dual-phase(ξ-PtAl_(2)+β-(Ni,Pt)Al)to single phase(β-(Ni,Pt)Al).Results of HTLCF tests showed an improvement in the HTLCF life around 11.5%in the unexposed coated specimen(pre-cyclic oxidation)as compared to unexposed bare specimen,while this rise for exposed coated specimen(post-cyclic oxidation)was only 5%.Although a mixed mode fracture morphology(ductile and brittle)was observed on the fracture surfaces of failed specimens,the wider regions of brittle fracture belonged to exposed coated/uncoated ones.

DNA damage,apoptosis and cell cycle changes induced by fluoride in rat oral mucosal cells and hepatocytes

AIM： To study the effect of fluoride on oxidative stress, DNA damage and apoptosis as well as cell cycle of rat oral mucosal cells and hepatocytes.METHODS： Ten male SD rats weighing 80N120 g were randomly divided into control group and fluoride group, 5 animals each group. The animals in fluoride group had free access to deionized water containing 150 mg/L sodium fluoride （NaF）. The animals in control group were given distilled water. Four weeks later, the animals were killed. Reactive oxygen species （ROS） in oral mucosa and liver were measured by Fenton reaction, lipid peroxidation product, malondialdehyde （MDA）, was detected by thiobarbituric acid （TBA） reaction, reduced glutathione （GSH） was assayed by dithionitrobenzoic acid （DTNB） reaction. DNA damage in oral mucosal cells and hepatocytes was determined by single cell gel （SCG） electrophoresis or comet assay. Apoptosis and cell cycle in oral mucosal cells and hepatocytes were detected by flow cytometry.RESULTS： The contents of ROS and MDA in oral mucosa and liver tissue of fluoride group were significantly higher than those of control group （P〈 0.01）, but the level of GSH was markedly decreased （P〈 0.01）. The contents of ROS, MDA and GSH were （134.73 ＋ 12.63） U/mg protein, （1.48 ＋ 0.13） mmol/mg protein and （76.38 ~ 6.71） mmol/ mg protein in oral mucosa respectively, and （143.45＋ 11.76） U/mg protein, （1.44：1：0.12） mmol/mg protein and （78.83±7.72） mmol/mg protein in liver tissue respectively. The DNA damage rate in fluoride group was 50.20% in oral mucosal cells and 44.80% in hepatocytes, higher than those in the control group （P 〈0.01）. The apop- tosis rate in oral mucosal cells was （13.63 ＋ 1.81） % in fluoride group, and （t2.76＋ 1.67） % in hepatocytes, higher than those in control group. Excess fluoride could differently lower the number of oral mucosal cells and hepatocytes at G0/G1 and S G2/M phases （P〈 0.05）.CONCLUSION： Excess fluoride can induce oxidative stress and DNA damage and lead to apoptosis and cell cycle change in rat oral mucosal cells and hepatocytes.

Catalytic performance of cerium iron complex oxides for partial oxidation of methane to synthesis gas

The cerium iron complex oxides oxygen carrier was prepared by the co-precipitation method. The reactions between methane and lattice oxygen from the complex oxides were investigated in a fixed micro-reactor system. The reduced oxygen carder could be re-oxidized by air and its initial state could be restored. The characterizations of the oxygen carders were studied using XRD, O2-TPD, and H2-TPR. The results showed that the bulk lattice oxygen of CeO2-Fe2O3 was found to be suitable for the partial oxidation of methane to synthesis gas. There were two kinds of oxygen species on the oxygen carrier： the stronger oxygen species that was responsible for the complete oxidation of methane, and the weaker oxygen species （bulk lattice oxygen） that was responsible for the selective oxidation of methane to CO and H2 at a higher temperature. Then, the lost bulk lattice oxygen could be selectively supplemented by air re-oxidation at an appropriate reaction condition. CeFeO3 appeared on the oxygen carrier after 10 successive redox cycles, however, it was not bad for the selectivity of CO and H2.

Effects of ORC Working Fluids on Combined Cycle Integrated with SOFC and ORC for Stationary Power Generation

The purpose of this study is to explore the effects of working fluid on conventional combined cycle integrated with pressurized solid oxide fuel cell (SOFC) and waste heat recovery organic Rankine cycle (ORC) for stationary utility power generation. The mathematical model of a natural gas fueled design configuration is developed in Matlab and Simulink and simulated with 14 working fluids. The effluent gases of SOFC undergo combustion in the combustion chamber and it is utilized in the gas turbine, steam turbine cycle and ORC. The model is compared with those found in literature and the parametric studies of temperature, flow rate, fuel utilization factor and exhaust gas on the system efficiency are examined. Results revealed that working fluids show a closely related behavior in efficiency at low pressure ratio and high flow fraction, fuel utilization, and temperature. R-123 was found to perform the best among 14 working fluids studied, yielding a system energy efficiency of 70% in the combined cycle integrated with SOFC and ORC.

Effect of Nitric Oxide on the Interaction Between Mitochondrial Malate Dehydrogenase and Citrate Synthase

Mitochondrial malate dehydrogenase （mMDH） and citrate synthase （CS） are sequential enzymes in Krebs cycle. mMDH, CS and the complex between mMDH and CS （mMDH＋CS） were treated with nitric oxide solution. The roles of notric oxide （NO） on the secondary structures and the interactions between mMDH and CS were studied using circular diehroism （CD） and Fourier transform surface plasmon resonance （FT-SPR）, respectivley. The effects of NO on the activities of mMDH, CS and mMDH＋CS were also studied. And the regulations by NO on mMDH and CS were simulated by PyMOL software. The results of SPR conifrmed that strong interaction between mMDH and CS existed and NO could signiifcantly regulate the interaction between the two enzymes. NO reduced the mass percents ofα-helix and increased that of random in mMDH, CS and mMDH＋CS. NO increased the activities of CS and mMDH＋CS, and inhibited the activity of mMDH. Graphic simulation indicated that covalent bond was formed between NO and Asn242 in active site of CS. However, there was no direct bond between NO and mMDH. The increase in activity of mMDH＋CS complex depended mostly on the interaction between NO and CS. All the results suggested that the regulations by NO on the activity and interaction between mMDH and CS were accord with the changes in mMDH, CS and mMDH＋CS caused by NO.

Effect of binder on the properties of iron oxide sorbent for hot gas desulfurization

The most difficult problem in hot gas desulfurization in Integrated Coal Gasification Combined Cycle （IGCC） is the pulverization of sulfur removal sorbents.Appropriate binders for hot gas sulfur removal sorbents can solve the pulverization problem.In this paper,six sorbents with binders of different argillaceous minerals were prepared by mechanical mixing method.Desulfurization behavior for hot gas desulfurization sorbents was investigated in a fixed-bed reactor.Result showed that sorbent NTKW2 with binder of clay had a better sulfidation performance.NTKW2 had a more stable performance than other sorbents in the continuous sulfidation-regeneration cycles.Sulfur capacity of sorbent remained the same in each cycle.The desulfurization efficiency and mechanical strength of NTKW2 were the best among the tested sorbents.The behavior of NTKW2 at different temperatures showed different performances,and the best reaction temperature was 550 ℃.Higher heat stability,sulfur capacity and desulfurization efficiency were found on NTKW2 in six continuous sulfidation-regeneration cycles.

Characteristic Surface Oxide Film Cracking Behavior of a Fe-Ni-Cr Alloy under In-phase and Out-of-phase Thermo-mechanical Fatigue

The surface oxide film cracking behavior of Fe-30Ni-20Cr alloy under in-phase and out-of-phase synchronizing thermal cycling with mechanical cycling was studied.Surface oxide film cracking along the grain boundary under in-phase overlapping was creep predominant fracture mechanisms.Strongly induced slip lines preceding were accompanied by the surface oxide film cracking under Out-of phase,and the shear cracking was dominant mode.Negative mean stress could counteract a part of the tensile component of alternative stress,so as to delay the cracking process under in-phase,but positive mean stress overlapping the tensile alternative stress could accelerate the cycling cracking process under out-of-phase.

Study on Degradation of La_(0.8)Pr_(0.2)Ni_(3.55)Co_(0.75)Mn_(0.4)Al_(0.3) Alloy Electrode in Process of Charge-discharge Cycles

The degradation of La 0.8 Pr 0.2 Ni 3.55 Co 0.75 Mn 0.4 Al 0.3 alloy electrode during charge discharge cycles was studied with analytical electron microscope (AEM) and scanning electron microscope (SEM). During the cycles, the alloy particles of the negative electrode were pulverized gradually. After 200 cycles, the pulverizing process basically ended and the larger particles were pulverized to below 10 μm. The particles were oxided at the rate of about 0.1 μm/100 times cycles. The oxide layer was porous and consisted of the La(OH) 3 and oxides of Pr, Co and Ni. Most of Pr, Mn and almost all of Al in the oxide layer were dissolved into the electrolyte. The oxidation of the alloy particles was one of the main factors of the decay of the discharge capacity of the negative electrode during the cycles.

Effects of laminar shear stress versus resveratrol on the citrulline-NO cycle in endothelial cells

Laminar shear stress (LSS) due to pulsatile blood flow enhances endothelial function by multiple mechanisms including NO production. Red wine and its constituent, resveratrol, have also been postulated to provide vascular protective effects. The aim of the present study was to compare the effects of mechanical LSS and pharmacological resveratrol treatments on the endothelial citrulline-NO cycle. Human umbilical vein endothelial cells (HUVECs) were treated with LSS (12 dyn·cm-2) or resveratrol (25 - 100 μM). The expressions of argininosuccinate synthetase 1 (ASS1), argininosuccinate lyase (ASL), nitric oxide synthase 3 (NOS3) and cationic amino acid transporter 1 (CAT1), and the production of NO were determined. The expressions of Kruppel-like factor (KLF) 2 and KLF4 as upstream regulators of ASS1 and NOS3 were also analyzed. LSS strongly increased the mRNA levels of ASS1 (8.3 fold) and NOS3 (5.4 fold) without significant effects on ASL and CAT1 mRNAs. Resveratrol increased the ASS1 mRNA level in a dose-dependent manner up to 3.8 fold at 100 μM. The effects of resveratrol on the expressions of KLF2 and KLF4 mRNAs were smaller than those of LSS. Protein levels of ASS1 and NOS3, and NO production were markedly increased by LSS but resveratrol (50 μM) increased only ASS1 protein level. The results of the current study showed that LSS had greater effects on the citrulline-NO cycle activity leading to NO production, compared to resveratrol. Because resveratrol was not so effective at stimulating the endothelial citrulline-NO cycle, further studies are needed to find more potent drugs that increase the expression of ASS1 and NOS3 genes.

Effects of Psychological Stress from a National License Examination on the Urine 8-Hydroxy-Deoxyguanosine Levels in Young Female Students, Taking into Account the Menstrual Cycle

Objective: Urine 8-hydroxy-deoxyguanosine (U8-OHdG) was a marker of oxidative stress-induced DNA damage;it was increased by psychological stress. Since the menstrual cycle may confound or modify the association between psychological stress and U8-OHdG. The aim of this study was to verify the effect of psychological stress from a national license examination on levels of U8-OHdG, which is a biomarker of oxidative stress. And the effects of women’s menstrual cycles, which should be considered in mental and physical assessments, on U8-OHdG, were evaluated. Methods: The subjects were 18 female university students at a medical university in whom Self-rating Depression Scale (SDS) scores, State-Trait Anxiety Inventory (STAI) scores, and U8-OHdG levels were measured in 3 phases of the menstrual cycle, the follicular phase, ovulatory phase, and luteal phase. The mean values were taken for the group during a time of classroom learning. The same measurements were also made one week before and the day after a national license examination and the measurements were compared among the three periods. Results and Conclusion: State anxiety and U8-OHdG levels were significantly higher in those with a week before the national license examination than in those with classroom lecture (State anxiety: p = 0.002, U8-OHdG levels: p = 0.007). The menstrual cycle did not show a significant correlation with U8-OHdG levels. This study demonstrated that levels of the oxidative stress biomarker U8-OHdG are not affected by changes in the menstrual cycle. It also showed that U8-OHdG levels increased with the psychological stress of a national license examination.