Among different Prussian Blue Analogues (PBAs), manganese hexacyanoferrate (MnHCF), with open framework and two abundant electroactive metal sites, exhibits high potential for the grid-scale aqueous rechargeable zinc-ion batteries (ARZIBs) application. Until now, the intercalation mechanism of Zn into MnHCF has not been clearly illustrated. In this work, combining different synchrotron X-ray techniques, the structural and microscopic evolution of MnHCF in 3 m ZnSO electrolyte is comprehensively studied, and a thorough understanding of the intercalation/release dynamic, in terms of local and long-range domain, is provided.
View Article and Find Full Text PDFHigh-entropy oxides (HEOs) have emerged as promising anode materials for next-generation lithium-ion batteries (LIBs). Among them, spinel HEOs with vacant lattice sites allowing for lithium insertion and diffusion seem particularly attractive. In this work, electrospun oxygen-deficient (Mn,Fe,Co,Ni,Zn) HEO nanofibers are produced under environmentally friendly calcination conditions and evaluated as anode active material in LIBs.
View Article and Find Full Text PDFManganese hexacyanoferrates (MnHCF) are promising positive electrode materials for non-aqueous batteries, including Na-ion batteries, due to their large specific capacity (>130 mAh g ), high discharge potential and sustainability. Typically, the electrochemical reaction of MnHCF associates with phase and structural changes, due to the Jahn-Teller (JT) distortion of Mn sites upon the charge process. To understand the effect of the MnHCF structure on its electrochemical performance, two MnHCF materials with different vacancies content are investigated herein.
View Article and Find Full Text PDFCopper sulfide has attracted increasing attention as conversion-type cathode material for, especially, solid-state lithium-based batteries. However, the reaction mechanism behind its extraordinary electroactivity is not well understood, and the various explanations given by the scientific community are diverging. Herein, the CuS reaction dynamics are highlighted by examining the occurring redox processes via a cutting-edge methodology combining X-ray absorption fine structure spectroscopy, and chemometrics to overcome X-ray diffraction limitations posed by the poor material's crystallinity.
View Article and Find Full Text PDFA growing body of evidence suggests that aggregated α-synuclein, the major constituent of Lewy bodies, plays a key role in the pathogenesis of Parkinson's disease and related α-synucleinopathies. Immunotherapies, both active and passive, against α-synuclein have been developed and are promising novel treatment strategies for such disorders. Here, we report on the humanization and pharmacological characteristics of ABBV-0805, a monoclonal antibody that exhibits a high selectivity for human aggregated α-synuclein and very low affinity for monomers.
View Article and Find Full Text PDFBackground: Currently, there is no established biomarker for Parkinson's disease (PD) and easily accessible biomarkers are crucial for developing disease-modifying treatments.
Objective: To develop a novel method to quantify cerebrospinal fluid (CSF) levels of α-synuclein protofibrils (α-syn PF) and apply it to clinical cohorts of patients with PD and atypical parkinsonian disorders.
Methods: A cohort composed of 49 patients with PD, 12 with corticobasal degeneration (CBD), 22 with progressive supranuclear palsy, and 33 controls, that visited the memory clinic but had no biomarker signs of Alzheimer's disease (AD, tau<350 pg/mL, amyloid-beta 42 (Aβ42)>530 pg/mL, and phosphorylated tau (p-tau)<60 pg/mL) was used in this study.
Scientists increasingly find themselves working in bilateral drug development alliances. Alliances are conceptually simple, but operationally challenging, resulting in the value-eroding misalignment and delays that alliances often experience. This case study of an exemplary collaboration between a small biotech and a global biopharmaceutical company is based on 15 interviews and a lessons-learned workshop conducted with the principal alliance team members.
View Article and Find Full Text PDFLithium-rich transition-metal-oxide cathodes are among the most promising materials for next generation lithium-ion-batteries because they operate at high voltages and deliver high capacities. However, their cycle-life remains limited, and individual roles of the transition-metals are still not fully understood. Using bulk-sensitive X-ray absorption and emission spectroscopy on Li[LiNiMnCo]O, we inspect the behavior of Mn, generally considered inert upon the electrochemical process.
View Article and Find Full Text PDFThe chemistry of copper(I) with water-soluble phosphines is an emergent area of study which has the objective of finding ligands that stabilize copper in its lower oxidation state. Cu(I) has been found relevant in the mechanism of copper transports into cells, and the accessibility of this oxidation state has implications in oxidative stress processes. For these reasons the possibility to deal with stable, water soluble copper(I) is an attractive approach for devising new biologically relevant metal-based drugs and chelating agents.
View Article and Find Full Text PDFThe phosphane Cu(I) complex [Cu(thp)][PF], 1 (thp=tris(hydroxymethyl)phosphane) shows notable in vitro antitumour activity against a wide range of solid tumours. Uptake experiments performed in 1-treated colon cancer cells by atomic absorption spectrometry, reveal that the antiproliferative activity is consistent with the intracellular copper content. The solution chemistry of this agent, investigated by means of X-ray Absorption Spectroscopy and spectrophotometric titrations in aqueous media, indicates that 1 is labile giving coordinative unsaturated [Cu(thp)] species (n=3 and 2) at micromolar concentrations.
View Article and Find Full Text PDFA combined X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) methodology is here presented on a series of partially and fully reduced Au(III) samples. This allows monitoring the relative fraction of Au(III) and Au(0) in the studied samples, displaying a consistent and independent outcome. The strategy followed is based, for the first time, on two structural models that can be fitted simultaneously, and it evaluates the correlation among strongly correlated parameters such as coordination number and the Debye-Waller factor.
View Article and Find Full Text PDFA charge transfer between Fe and Co in cobalt hexacyanoferrate has been observed for the first time by anatase doping. The charge transfer, which involves a spin transition at the Co site, is supported by high-resolution XANES spectra. EXAFS evidenced a consistent change (10%) of the Co-N first shell.
View Article and Find Full Text PDFTetrahedral copper(I) TpCuP complexes 1-15, where Tp is a N,N,N-tris(azolyl)borate and P is a tertiary phosphine, have been synthesized and characterized by means of NMR, ESI-MS, and XAS-EXAFS, and X-ray diffraction analyses on the representative complexes 1 and 10, respectively. All copper(I) complexes were evaluated for their antiproliferative activity against a panel of human cancer cell lines (including cisplatin and multidrug-resistant sublines). The two most effective complexes [HB(pz)3]Cu(PCN), 1, and [HB(pz)3]Cu(PTA), 2, showed selectivity toward tumor vs normal cells, inhibition of 26S proteasome activity associated with endoplasmic reticulum (ER) stress, and unfolded protein response (UPR) activation.
View Article and Find Full Text PDFThe novel N-heterocyclic carbene ligand precursor NaHIm(PrSO3) (sodium 3,3'-(1H-imidazole-3-ium-1,3-diyl)dipropane-1-sulfonate) and the related silver carbene complex [Na4(Im(PrSO3))2]AgCl have been synthesized and characterized. Recrystallization of the analogous [Im(AcEt)]AgCl complex allowed the development of X-ray analysis which led to achieve relevant structural information concerning this silver(I) derivative. Both sulfonate- and ester-functionalized silver(I) N-heterocyclic carbenes (NHCs) were evaluated for their antiproliferative activities in a wide panel of human cancer cells.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2013
Two-dimensional inorganic solids, such as layered double hydroxides (LDHs), also defined as anionic clays, have open structures and unique anion-exchange properties which make them very appropriate materials for the immobilization of anions and biomolecules that often bear an overall negative charge. This review aims to describe the important aspects and new developments of electrochemical sensors and biosensors based on LDHs, evidencing the research from our own laboratory and other groups. It is intended to provide an overview of the various types of chemically modified electrodes that have been developed with these 2D layered materials, along with the significant advances made over the last several years.
View Article and Find Full Text PDFA deep structural investigation predominantly by X-ray spectroscopic techniques is conducted on films of copper hexacyanoferrate (CuHCF) deposited under different conditions, aimed at establishing structure-properties relationships. We show that the potentiodynamic electrosynthesis of CuHCF on carbon-based surfaces produces a highly disordered material, with a variable amount of Prussian Blue (PB). The subsequent Cu(2+) intercalation induces the partial conversion of PB into CuHCF, which explains the improved electrocatalytic properties after the intercalation process.
View Article and Find Full Text PDFNew nitroimidazole and glucosamine conjugated heteroscorpionate ligands, namely 2,2-bis(3,5-dimethyl-1H-pyrazol-1-yl)-N-(2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl)acetamide (L(MN)) and 1,3,4,6-tetra-O-acetyl-2-{[bis(3,5-dimethyl-1H-pyrazol-1-yl)acetyl]amino}-2-deoxy-β-D-glucopyranose (L(DAC)), respectively, were synthesized by direct coupling of preformed side chain acid and amine components. The related copper(II) complexes {[(L(MN))(2)Cu]Cl(2)}, and {[(L(DAC))(2)Cu]Cl(2)} have been prepared from the reaction of CuCl(2)*2H(2)O with L(MN) or L(DAC) ligand in methanol solution. Single crystal structural characterization was undertaken for the L(MN) ligand.
View Article and Find Full Text PDFHarmine, a β-carboline alkaloid, is a high affinity inhibitor of the dual specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) protein. The DYRK1A gene is located within the Down Syndrome Critical Region (DSCR) on chromosome 21. We and others have implicated DYRK1A in the phosphorylation of tau protein on multiple sites associated with tau pathology in Down Syndrome and in Alzheimer's disease (AD).
View Article and Find Full Text PDFWe investigated, both in the solid state and in aqueous solution, the coordination environment and stability behavior of four macrocyclic ligands (three N(2)S(2) and one N(3)S(2)) and of the corresponding Cu(II) complexes. The structural characterization in the solid state of the copper derivatives was performed by X-Ray Absorption Spectroscopy. Copper is found to be 4-fold coordinated with a CuN(2)S(2) environment with different Cu-S distances depending on the size of the macrocyclic ring.
View Article and Find Full Text PDFVanadium pentoxide materials prepared through sol-gel processes act as excellent intercalation hosts for lithium as well as polyvalent cations. A chemometric approach has been applied to study the X-ray absorption near-edge structure (XANES) evolution during in situ scanning of the Cu(0.1)V(2)O(5) xerogel/Li ions battery.
View Article and Find Full Text PDFDimebon (dimebolin) treatment enhances cognition in patients with Alzheimer's disease (AD) or Huntington's disease. Although Dimebon was originally thought to improve cognition and memory through inhibition of acetylcholinesterase (AChE) and the N-methyl-d-aspartate (NMDA) receptor, the low in vitro affinity for these targets suggests that these mechanisms may not contribute to its clinical effects. To test this hypothesis, we assessed whether Dimebon enhances cognition in rats and if such an action is related to either mechanism or additional candidate mechanisms.
View Article and Find Full Text PDFThe impact of serotonergic neurotransmission on brain dopaminergic pathways has substantial relevance to many neuropsychiatric disorders. A particularly prominent role has been ascribed to the inhibitory effects of serotonin 2C receptor (5-HT(2C)R) activation on physiology and behavior mediated by the mesolimbic dopaminergic pathway, particularly in the terminal region of the nucleus accumbens. The influence of this receptor subtype on functions mediated by the nigrostriatal dopaminergic pathway is less clear.
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