87 research outputs found

    Central Angiotensin II Stimulation Promotes β Amyloid Production in Sprague Dawley Rats

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    BACKGROUND: Stress and various stress hormones, including catecholamines and glucocorticoids, have recently been implicated in the pathogenesis of Alzheimer's disease (AD), which represents the greatest unresolved medical challenge in neurology. Angiotensin receptor blockers have shown benefits in AD and prone-to-AD animals. However, the mechanisms responsible for their efficacy remain unknown, and no studies have directly addressed the role of central angiotensin II (Ang II), a fundamental stress hormone, in the pathogenesis of AD. The present study focused on the role of central Ang II in amyloidogenesis, the critical process in AD neuropathology, and aimed to provide direct evidence for the role of this stress hormone in the pathogenesis of AD. METHODOLOGY/PRINCIPAL FINDINGS: Increased central Ang II levels during stress response were modeled by intracerebroventricular (ICV) administration of graded doses of Ang II (6 ng/hr low dose, 60 ng/hr medium dose, and 600 ng/hr high dose, all delivered at a rate of 0.25 µl/hr) to male Sprague Dawley rats (280-310 g) via osmotic pumps. After 1 week of continuous Ang II infusion, the stimulation of Ang II type 1 receptors was accompanied by the modulation of amyloid precursor protein, α-, β-and γ-secretase, and increased β amyloid production. These effects could be completely abolished by concomitant ICV infusion of losartan, indicating that central Ang II played a causative role in these alterations. CONCLUSIONS/SIGNIFICANCE: Central Ang II is essential to the stress response, and the results of this study suggest that increased central Ang II levels play an important role in amyloidogenesis during stress, and that central Ang II-directed stress prevention and treatment might represent a novel anti-AD strategy

    Progress in polyanion-type cathode materials for lithium ion batteries

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    Recent progress on the polyanion-type cathode materials for lithium ion batteries is reviewed. Emphasis is placed on the discussion of the relationships between structures and properties of the cathode materials, especially on the role of the polyanion and how to improve their low electronic conductivity

    Go@Se@ni cathode materials for lithium-selenium battery

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    Selenium is a promising cathode material for high-energy lithium batteries. In this work, selenium was electrodeposited on nickel foam from aqueous selenite solution. The influences of pH values and current density on electrodeposited Se@Ni were investigated. It is found that electrodeposition at pH 7 and 0.5 mA cm −2 enables high current efficiency and produces uniform and smooth deposits. Graphene oxide (GO) was further coated on Se@Ni through physical adsorption to produce GO@Se@Ni. The developed GO@Se@Ni electrode delivers a high initial specific capacity of 593 mAh g −1 and good capacity retention over 100 cycles at 0.1 C

    Superior Stability Secured by a Four-Phase Cathode Electrolyte Interface on a Ni-Rich Cathode for Lithium Ion Batteries.

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    A multifunctional coating with high ionic and electronic conductivity is constructed on the surface of LiNi0.8Co0.1Mn0.1O2 (NCM) to boost the battery stability upon cycling and during storage as well. Phosphoric acid reacts with residual lithium species on the pristine NCM to form a Li3PO4 coating with extra carbon nanotubes (CNTs) penetrating through, which shows high ionic and electronic conductivity. NCM, Li3PO4, CNTs, and the electrolyte jointly form a four-phase cathode electrolyte interface, which plays a key role in the great enhancement of capacity retention, from 50.3% for pristine NCM to 84.8% for the modified one after 500 cycles at 0.5C at room temperature. The modified NCM also delivers superior electrochemical performances at a high cut-off voltage (4.5 V), high temperature (55 °C), and high rate (10C). Furthermore, it can deliver 154.2 mA h g-1 at the 500th cycle after exposed to air with high humidity for 2 weeks. These results demonstrate that the well-constructed multifunctional coating can remarkably enhance the chemical and electrochemical performances of NCM. The improved cycling, storage, and rate performance are attributed to the four-phase cathode electrolyte interface delivering high electron and ionic conductivity and securing the cathode against attack. This work broadens the horizon for constructing effective electrode/electrolyte interfaces for electrochemical energy storage and conversion

    Research progress in solid polymer electrolyte-lithium metal anode interface

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    Solid state lithium battery is expected to be one of the next generation of battery systems with high energy density in the field of high energy. Based on the constructure characteristics and related formation mechanism of interface between solid polymer electrolyte and lithium anode, the impact of interface contact, interface chemistry and electrochemical reaction, and moreover, the growing process of lithium dendrite and other problems on the interface stability and compatibility were systematically discussed in this review.Thus, the application of doping modification, structure design, and other methods for the interfaces between polymer matrix and lithium anode were also emphasized. In addition, the common interface characterization methods and their applications on the interface between solid polymer electrolyte and lithium anode were also reviewed. Finally, based on the relevant strategies of designing and constructing a stable polymer solid electrolyte-lithium anode interface, the development prospects of interface optimization methods such as doping and core layer design were analyzed and prospected in this paper
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