Ox System Research Articles

The interaction between orexin, sleep deprivation and Alzheimer's disease: Unveiling an Emerging Connection.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and memory loss. Sleep-wake disorders are an extremely predominant and often disabling aspect of AD. Ox is vital in maintaining the sleep-wake cycle and promoting wakefulness. Dysfunction of Ox signaling has been associated with sleep disorders such as narcolepsy. In AD patients, the increase in cerebrospinal fluid Ox levels is related to parallel sleep deterioration. The relationship between AD and sleep disturbances has gained increasing attention due to their potential bidirectional influence. Disruptions in sleep patterns are commonly observed in AD patients, leading researchers to investigate the possible involvement of Ox in sleep disturbances characteristic of the disease. This review article explores the role of the Ox system in AD, and the intricate relationship between AD and sleep, highlighting the potential mechanisms, impact on disease pathology, and therapeutic interventions to improve sleep quality in affected individuals.

Oxidized Ti3Al(1-x)SnxC2 MAX phases as negative electrode materials for sodium ion batteries

Materials proposed for the negative electrodes in sodium-ion batteries often include oxides capable of reacting with Na+ through intercalation, conversion, or alloying. While these oxides offer high specific capacities, they suffer from poor mechanical stability. A novel approach to address this issue involves designing tailored nanocomposites based on the (Ti/Sn)Ox system, achieved through partial oxidation of tin-containing MAX phase (Ti3Al(1-x)SnxC2, x = 0.4 and 0.7). By employing this strategy, we have developed composite electrodes based on Ti(1-y)SnyO2 and MAX phase, which exhibit remarkable durability, withstanding over 600 cycles in half-cells. These electrodes also demonstrate charge efficiencies higher than 99.8 % and specific capacities comparable to MXenes electrodes. These outstanding electrochemical performances are further validated at the full-cell level when combined with Na0.44MnO2 positive electrodes. The reaction mechanism between the composite and the sodium ion was also studied using in-situ techniques (Raman and XAS) and the contribution of the different components during sodiation and de-sodiation was highlighted.

Solution-processed high entropy metal oxides as dielectric layers with high transmittance and performance and application in thin film transistors

High entropy metal oxides (HEMOs) are emerging materials with unique structures and functional properties, but it's barely researched as dielectric materials. This paper investigates solution-processed HEMOs as the dielectric material. Six HEMOs systems were compared and the role of various metal oxides in the high entropy system is revealed. It turns out that the (HfMgTiYZr)Ox system has the most excellent dielectric properties with a low leakage current density of 2.9 × 10−7A/cm2@2MV/cm and a high dielectric constant of 13.0. Moreover, the transmittance of the films is over 88% in the range of the visible light. The high performances of the HEMOs derive from the complex internal structure and the single solid solution phase. Applying (HfMgTiYZr)Ox as dielectric layers, the thin film transistors attain an Ion/off of 6.3 × 108, a mobility of 14.2cm2/vs, a ss of 0.34 V, and a Vth of 1.3 V. In this paper, we demonstrate that HEMOs have good dielectric properties and can be used in thin film transistors which implies a promising future in the application of electronic devices.

Hypocretin/orexin system in the nucleus accumbens as a promising player in the extinction and reinstatement of methamphetamine-induced CPP

One of the main obstacles in treating psychostimulant addiction is relapse even after long-term abstinence. The nucleus accumbens (NAc) is located in the basal forebrain, responsible for regulating several behaviors, specifically reward-related effect of psychostimulants. In the current study, an unbiased place conditioning paradigm was performed to inquire the role of the hypocretin/orexin system in the NAc in the extinction and reinstatement of methamphetamine (Meth)-induced conditioned place preference (CPP). Similar to previous investigations, rats were conditioned with Meth (1 mg/kg; sc) for five consecutive days to elicit CPP. The rats underwent Meth conditioning protocol received SB334867 or TCS OX2 29, an orexin receptor 1 (OXr1) antagonist or orexin receptor 2 (OXr2) antagonist (0, 3, 10, and 30 nmol/0.5 μL DMSO %12) in the NAc during the extinction period to elucidate the role of OXrs on the extinction of Meth-induced CPP. Meanwhile, extinguished rats received SB334867 or TCS OX2 29 (0, 1, 3, 10, and 30 nmol/0.5 μL DMSO %12) in the NAc prior to an effective priming dose of Meth to evaluate the impact of OXr antagonists on the reinstatement of Meth-induced CPP. The current data pointed out intra-NAc microinjection of SB334867 or TCS OX2 29 blocked both extinction and reinstatement of Meth-induced CPP. In addition, the OXr1 antagonist was more potent than the OXr2 antagonist to suppress both extinction and reinstatement phases of Meth-induced CPP. Based on the current data, the OX system in the NAc is extensively implicated in the reward properties of Meth; therefore, modulation of this system has therapeutic potential in treating psychostimulant use disorders.

Synthesis and characterization of a new Positron emission tomography probe for orexin 2 receptors neuroimaging

The orexin receptors (OXRs) have been involved in multiple physiological and neuropsychiatric functions. Identification of PET imaging probes specifically targeting OXRs enables us to better understand the OX system. Seltorexant (JNJ-42847922) is a potent OX2R antagonist with the potential to be an OX2R PET imaging probe. Here, we describe the synthesis and characterization of [18F]Seltorexant as an OX2R PET probe. The ex vivo autoradiography studies indicated the good binding specificity of [18F]Seltorexant. In vivo PET imaging of [18F]Seltorexant in rodents showed suitable BBB penetration with the highest brain uptake of %ID/cc = 3.4 at 2 min post-injection in mice. The regional brain biodistribution analysis and blocking studies showed that [18F]Seltorexant had good binding selectivity and specificity. However, pretreatment with unlabelled Seltorexant and P-gp competitor CsA observed significantly increased brain uptake of [18F]Seltorexant, indicating [18F]Seltorexant could interact P-gp at the blood-brain barrier. Our findings demonstrated that [18F]Seltorexant is a potential brain OX2R PET imaging probe, which paves the way for new OX2R PET probes development and OX system investigation.

Escitalopram alters the hypothalamic OX system but does not affect its up-regulation induced by early-life stress in adult rats.

We hypothesized that there is a relationship between the orexinergic system (OX) alterations and changes elicited by escitalopram or venlafaxine in adult rats subjected to maternal separation (MS). This animal model of childhood adversity induces long-lasting consequences in adult physiology and behavior. Male Wistar rats from the control and MS groups were injected with escitalopram or venlafaxine (10 mg/kg) IP from postnatal day (PND) 69–89. Adult rats were subjected to behavioral assessment, estimation of hypothalamic-pituitary-adrenal (HPA) axis activity and analysis of the OX system (quantitative PCR and immunohistochemistry) in the hypothalamus and amygdala. MS caused anxiety- and depressive-like behavior, endocrine stress-related response, and up-regulation of the OX system in the hypothalamus. Escitalopram, but not venlafaxine, increased the activity of hypothalamic OX system in the control rats and both drugs had no effect on OXs in the MS group. The disturbed signaling of the OX pathway may be significant for harmful long-term consequences of early-life stress. Our data show that the normal brain and brain altered by MS respond differently to escitalopram. Presumably, anti-anxiety and antidepressant effects of this drug do not depend on the activity of hypothalamic OX system.

Photodegradation of cresol red by a non-iron Fenton process under UV and sunlight irradiation: Effect of the copper(II)-organic acid complex activated by H2O2

The copper(II)-organic acid complex activated by H2O2 was known to be a non-iron Fenton process. In this work, photodegradation of cresol red (CR) by a non-iron Fenton process (Cu(II)-Ox- H2O2) using Cu(II)-Oxalic acid (Ox) complex as catalyst was investigated. The results demonstrate that the combination of light and Cu(II)-Ox complex in situ generates H2O2 by producing reactive oxidants through the reaction of Cu(I) with H2O2. The second part, dedicated to the study of capacity of Cu(II)-Ox- H2O2 system to induce the degradation of CR. Kinetics experiments showed that the external supply of H2O2 to the Cu(II)-Ox system was found to further enhance the effectiveness of CR. Here, we further investigate the synergistic effect in different systems (two-component system UV/Cu(II)-Ox, and three-component system UV/Cu(II)-Ox-H2O2 with CR under the same conditions. Parameters such as pH, the initial concentrations of Cu(II), oxalic acid (Ox) and H2O2 were all investigated. Furthermore, the radical scavenging activity studies indicated that •OH was the dominant active species responsible for CR removal, and O2–• could promote CR degradation in Cu(II)-Ox-H2O2 system. These result strongly confirmed the feasibility of non-iron Fenton process (Cu(II)-Ox- H2O2) under excitation by sunlight.

Dysregulation of the orexin/hypocretin system is not limited to narcolepsy but has far-reaching implications for neurological disorders.

Neuropeptides orexin A and B (OX-A/B, also called hypocretin 1 and 2) are released selectively by a population of neurons which projects widely into the entire central nervous system but is localized in a restricted area of the tuberal region of the hypothalamus, caudal to the paraventricular nucleus. The OX system prominently targets brain structures involved in the regulation of wake-sleep state switching, and also orchestrates multiple physiological functions. The degeneration and dysregulation of the OX system promotes narcoleptic phenotypes both in humans and animals. Hence, this review begins with the already proven involvement of OX in narcolepsy, but it mainly discusses the new pre-clinical and clinical insights of the role of OX in three major neurological disorders characterized by sleep impairment which have been recently associated with OX dysfunction, such as Alzheimer's disease, stroke and Prader Willi syndrome, and have been emerged over the past 10years to be strongly associated with the OX dysfunction and should be more considered in the future. In the light of the impairment of the OX system in these neurological disorders, it is conceivable to speculate that the integrity of the OX system is necessary for a healthy functioning body.

Formation and Properties of Amorphous Multi-Component (CrFeMoNbZr)Ox Thin Films

In this work, a new multi-component (CrFeMoNbZr)Ox system was developed. The thin films presented dual-phase amorphous structures, comprising a dominant amorphous alloy phase and a small amount of an amorphous oxide phase. The thin films showed higher hardness and better corrosion resistance than a commercial Zr-based alloy. The combined properties of high hardness and superior corrosion-resistance make the amorphous thin film a candidate for coating materials on commercial Zr-based alloys for engineering applications.

Role of Fe(III) and Oxalic Acid in the photo-Fenton System for 3-Methylphenol Degradation in Aqueous Solution under Natural and Artificial Light

Abstract The Fenton process has been widely studied in the treatment of wastewater but unfortunately this process can only work under acidic pH conditions. To overcome these disadvantages, the Fenton modified by adding chelating agents such as oxalic acid (Ferrioxalate complex (Fe(III)Ox) since its high solubility in aqueous media can broaden the available pH range of the Fenton reaction to near neutral pH. In this study, The photooxidation efficiencies of 3-methylphenol (3MP) catalyzed by Fe(III) and oxalic acid was investigated. The results show that the photodegradation Of 3MP is slow in the presence of Fe(III) or oxalic acid alone. However, it is markedly enhanced when Fe(III)Ox complex coexist. The concentration of the complex is optimized to the ratio ([Fe(III)Ox] = 3/12). Fe(III)Ox plays a positive role in the photo-Fenton system, especially at higher pH = 5.5. Oxygen is essential to the formation of oxidative species and, as a consequence, for the pollutant degradation. Additionally, the use of tertio-butanol as a scavenger confirmed the intervention of . OH in the 3MP photodegradation. 3MP degradation mechanisms have been elucidated and photoproducts are identified by comparison with authentic products. To get closer to the environmental conditions, the effect of main elements present naturally in the aquatic ecosystem such as humic substances and bicarbonates was examined. The photodegradation of 3MP through Fe(III)Ox system under solar light was significantly accelerated in comparison with artificial irradiation at 365 nm. Measuring chemical oxygen demand (COD) leads to mineralization which decreases the toxicity of 3MP solution. This work also demonstrates that this system is an encouraging method for the treatment of organic pollutants in the natural environment.

Alkaline-stable nickel manganese oxides with ideal band gap for solar fuel photoanodes.

Combinatorial (photo)electrochemical studies of the (Ni-Mn)Ox system reveal a range of promising materials for oxygen evolution photoanodes. X-ray diffraction, quantum efficiency, and optical spectroscopy mapping reveal stable photoactivity of NiMnO3 in alkaline conditions with photocurrent onset commensurate with its 1.9 eV direct band gap. The photoactivity increases upon mixture with 10-60% Ni6MnO8 providing an example of enhanced charge separation via heterojunction formation in mixed-phase thin film photoelectrodes. Density functional theory-based hybrid functional calculations of the band edge energies in this oxide reveal that a somewhat smaller than typical fraction of exact exchange is required to explain the favorable valence band alignment for water oxidation.

Electric and magnetic properties of magnetic (CoFeTaB)(100−x)Ox films

By the controlling of oxygen flow rate, the oxygen content has been altered in the (CoFeTaB)(100−x)Ox system, a newly reported possible magnetic semiconductor. The electric and magnetic properties of (CoFeTaB)(100−x)Ox films are dependent on the oxygen content of (CoFeTaB)(100−x)Ox films. The resistivity of the grown (CoFeTaB)(100−x)Ox films could be altered from 3.77×10−4 Ω·cm to insulator. Correspondingly, the magnetic behavior of the grown (CoFeTaB)(100−x)Ox films was varied from ferromagnetism to paramagnetism. The increase in the resistivity was mainly attributed to the enhanced oxidization of metal Co; and the magnetism conversion was resulted from the decrease of ferromagnetic Fe3+ and increase of paramagnetic Co2+ in the grown films. These findings provide the fundamental reference for tailoring the electric and magnetic properties of (CoFeTaB)(100−x)Ox materials for potential applications in spintronics.

Rheokinetics in curing process of polyfurfuryl alcohol: effect of homologous acid catalysts

Curing reaction of polyfurfuryl alcohol (PFA) resin was investigated using rheological measurements in the presence of different acid catalysts. A homologous series of dicarboxylic acid catalysts with even number of carbons of 2, 4 and 6 were chosen, i.e., oxalic acid (OX, 2 carbon), succinic acid (SU, 4 carbon) and adipic acid (AD, 6 carbon). Acidity of these catalysts in terms of pK a was in the range of 1.25–4.43. Firstly, non-isothermal curing kinetics were investigated, and then, isothermal studies were performed at three different temperatures using 3 and 5 wt% of each acid catalyst. Isothermal cure behavior was best described by an empirical Arrhenius model of viscosity. An isoconversional method was applied to compute the changes in the effective activation energy as a function of degree of conversion. The change in activation energy at 50–10 kJ mol−1 was observed for PFA/3 wt% OX system due to the vitrification and diffusion-controlled processes. Gel time, t gel, was determined as a function of curing temperature, acid catalyst type and its concentration. The gelation time was consistent for all the formulations with an extent of conversion of about 0.7. Significant differences were observed in the curing behavior of resins in the presence of different acid catalysts. Increasing of the curing temperature significantly accelerated the curing process and increased curing rate constant of the PFA resin.

Rapid degradation of sulfonamides in a novel heterogeneous sonophotochemical magnetite-catalyzed Fenton-like (US/UV/Fe3O4/oxalate) system

A novel sonophotochemical Fenton-like system was investigated in this study for degradation of antibiotic sulfamethazine (SMZ). In the presence of oxalic acid (Ox), the heterogeneous Fe3O4-catalyzed system (US/UV/Fe3O4/Ox) could induce in-situ generation of H2O2 and also Fenton-like reaction. A Significant synergistic SMZ degradation including significantly enhanced SMZ mineralization and detoxification was achieved in the system, as compared to its corresponding individual systems. Ultrasound (US) treatment could eliminate the initial lag period of SMZ degradation which appeared in UV/Fe3O4/Ox system without the pre-dissolution phase. This phenomenon was evidenced by significant enhancements in the initial dissolution rate of the iron oxides as well as production rate of the reactive oxygen species (ROS). A reaction mechanism involving a heterogeneous/homogenous iron cycle and a series of homogenous radical reactions was proposed. The promotional role of US could be mostly ascribed to the sonochemcial cavitation effect in both heterogeneous solid–liquid interphase reactions and homogenous radical reactions. The cleavage of SN bond via •OH attack would be the main SMZ decomposition pathway. The solution pH and [Fe3O4:Ox] ratio were the two important factors for SMZ degradation. The repeating SMZ degradation tests of the US/UV/Fe3O4/Ox system also suggested that Fe3O4 was a favorable catalyst for application of the system in wastewater treatment.

Increased number of orexin/hypocretin neurons with high and prolonged external stress-induced depression

It has been found that dysregulation in the orexin/hypocretin (Ox/HCRT) neuropeptide system in the lateral hypothalamus (LHA) is known to affect sleep disorder, depression and motor activities. However, to date there is no common agreement regarding the resulting specific changes induced in the Ox system. In this study, we inject corticosterone to produce stress-induced depressed mice and investigate the Ox neuronal and corresponding behavioural changes. Different doses (10, 20, 50mg/kgbw) of corticosterone were injected in adult mice, and then were tested in the open field test, forced swim test, tail suspension test, elevated plus maze test and motor activity measurements to validate the depressed animal model. Significant dose-dependent behavioural changes were observed in correlation with the doses of corticosterone. The effect is most significant and robust in the high 50mg/kgbw dose group five weeks after injection. Interestingly, we found on average a reduction in motor activity during the 12-hour dark phase (awake) of the depressed mice and no significant change during the light phase (asleep). Finally, using confocal microscopy, immunofluorescence (IF) analysis shows a significant increase (∼20%) in the number of Ox neurons in the LHA of the depressed mice as compared to the age-matched controls. This study suggests that an increase in Ox neuronal signaling may be functionally linked to high and prolonged external stress-induced depression.

13C and 27Al NMR Study of Complexation between Aluminium Ion and Simple Dicarboxylic Acids under an Acidic Condition: New Peak Assignments of 27Al NMR Spectra of Mixed Solutions of Al3+ and Simple Dicarboxylic Acids

Due to a consideration of Al detoxicification by simple carboxylic acid, the interaction between aluminium ion (Al³⁺) and three dicarboxylic acids (oxalic acid (OX), malonic acid (MA) and succinic acid (SU)) under an acidic condition was investigated using ¹³C and ²⁷Al NMR techniques. Based on deconvolution of the ²⁷Al NMR spectra and quantitative ¹³C NMR spectra, the structure of each complex was elucidated. Especially, we focused on the peak assignments of ²⁷Al NMR spectra by combining of the results of quantitative ¹³C NMR spectra. In the OX system, the peak at 16 ppm in the ²⁷Al NMR spectrum originates from Al(OX)₃³⁻ and Al(OX)₂⁻, and the ratio of each complex depends on the OX/Al molar ratio. In the MA system, the three complexes (Al(MA)₂⁻, Al(MA)₃³⁻ and Al(MA)⁺) are represented in the peak at 2 ppm in the ²⁷Al NMR spectrum. The assignment of peaks in the ²⁷Al NMR spectra in this study differs from those described in previous papers.

Central administration of an orexin receptor 1 antagonist prevents the stimulatory effect of Olanzapine on endogenous glucose production

Atypical antipsychotic drugs such as Olanzapine (Olan) induce weight gain and metabolic changes associated with the development of type 2 diabetes. The mechanisms underlying these undesired side-effects are currently unknown. It has been shown that peripheral injections of Olan activate neurons in the lateral hypothalamus/perifornical area and that a large part of these neurons are orexin (Ox) A-positive. We investigated further the possible involvement of the central Ox system in the metabolic side-effects of Olan by comparing the hyperglycaemic effects of an intragastric (IG) Olan infusion between animals treated intracerebroventricularly (ICV) with an Ox-1 receptor antagonist (SB-408124) or vehicle. As observed in previous studies IG Olan caused an increase in blood glucose, endogenous glucose production and plasma glucagon levels. ICV pre-treatment with the Ox-1 receptor antagonist did not affect the Olan-induced hyperglycaemia or increased plasma glucagon concentrations, but the increased endogenous glucose production was blunted by the ICV SB-408124 treatment. From these results we conclude that the metabolic side-effects of Olan are partly mediated by the hypothalamic Ox system.

CO-DOPED POLYPYRROLE COATINGS FOR STAINLESS STEEL PROTECTION

Polypyrrole (PPy) films have been successfully electrodeposited on stainless steel substrates in aqueous solution. In this work, three systems of electrolytes were studied: oxalic acid, dodecylbenzenesulfonic acid (DBSA) and a mixture of oxalic acid and DBSA. A combination of XPS and TOF–SIMS revealed the formation of an iron oxalate layer at the interface between the oxalic acid-doped PPy (PPy(Ox)) and stainless steel and a thin layer of DBSA was observed at the interface between DBSA-doped PPy (PPy(DBSA)) and stainless steel. Similar to the PPy(Ox) system, an iron oxalate was also present at the co-doped PPy/stainless steel interface. Cyclic voltammetry indicated that an iron oxalate layer initially formed at the surface of the stainless steel when the co-doping system was used. The adhesion strength and corrosion performance of the PPy coating on stainless steel were evaluated by lap shear tests and an anodic potentiodynamic polarization technique, respectively. The co-doped PPy-coated stainless steel exhibited the best adhesion and a significant shift of corrosion potential to the positive direction. This finding opens the possibility for the co-doped PPy coating to be deployed as a strongly adherent corrosion inhibitor by using a simple one-step electropolymerization process.

Combinatorial Fabrication and Characterization of Ternary La2O3–Mn2O3–Co3O4 Composition Spreads

We describe the screening of large combinatorial oxide libraries for determining their electric transport characteristics. Complete full ternary composition spreads of La2O3–Mn2O3–Co3O4 oxide alloys were deposited onto single conducting Nb-doped SrTiO3 substrates by the pulsed laser deposition technique incorporating a moving shutter and a rotating substrate holder. The electrical resistance of the spreads was determined using a custom-designed scanning conducting probe. We found that a single electrically conducting area in the ternary spread develops into two branches to LaMnO3 perovskites close to the ideal LaMnO3 stoichiometry and to a wide La0.65Co0.35OX–La0.20Co0.80OX system with perovskite-related structures. We also discovered that compositions along the tie line [La0.20Co0.65Mn0.15OX–La0.57Co0.20Mn0.23OX] exhibit the weakest temperature dependence and therefore could be used in fabricating of stable thin film resistors and gas sensors.

Superconducting glass-ceramics in BiSrCaCu2Al0.5Ox—Comparison between rod and powder compacted specimens

Superconducting properties are studied for glass-ceramics which were prepared by reheating glass rods and the glass powder compacts in the BiSrCaCu2Al0.5Ox system, respectively. The glass-ceramic rod specimens obtained by reheating rod glass at 800–830 °C for 50 h have a Tc (R = 0) of 85 K, while the disk specimens obtained by reheating the powdered glass compacts in the same way do not exhibit superconductivity above 77 K. This difference in superconductivity between the specimens is discussed in terms of the crystallization process and the amount of oxygen absorption of the specimens during heating.