Understanding Li-ion transport is key for the rational design of superionic solid electrolytes with exceptional ionic conductivities. LiNbOCl is reported to be one of the most highly conducting materials in the recently realized new class of soft oxyhalide solid electrolytes, exhibiting an ionic conductivity of ∼11 mS·cm. Here, we apply X-ray/neutron diffraction and pair distribution function analysis─coupled with density functional theory/ab initio molecular dynamics (AIMD)─to determine a structural model that provides a rationale for the high conductivity that we observe experimentally in this nanocrystalline solid.
View Article and Find Full Text PDFMultivalent battery chemistries have been explored in response to the increasing demand for high-energy rechargeable batteries utilizing sustainable resources. Solvation structures of working cations have been recognized as a key component in the design of electrolytes; however, most structure-property correlations of metal ions in organic electrolytes usually build upon favorable static solvation structures, often overlooking solvent exchange dynamics. We here report the ion solvation structures and solvent exchange rates of magnesium electrolytes in various solvents by using multimodal nuclear magnetic resonance (NMR) analysis and molecular dynamics/density functional theory (MD/DFT) calculations.
View Article and Find Full Text PDFThe dynamics, orientational anisotropy, diffusivity, viscosity, and density were measured for concentrated lithium salt solutions, including lithium chloride (LiCl), lithium bromide (LiBr), lithium nitrite (LiNO), and lithium nitrate (LiNO), with methyl thiocyanate as an infrared vibrational probe molecule, using two-dimensional infrared spectroscopy (2D IR), nuclear magnetic resonance (NMR) spectroscopy, and viscometry. The 2D IR, NMR, and viscosity results show that LiNO exhibits longer correlation times, lower diffusivity, and nearly 4 times greater viscosity compared to those of the other lithium salt solutions of the same concentration, suggesting that nitrite anions may strongly facilitate structure formation via strengthening water-ion network interactions, directly impacting bulk solution properties at sufficiently high concentrations. Additionally, the LiNO and LiNO solutions show significantly weakened chemical interactions between the lithium cations and the methyl thiocyanate when compared with those of the lithium halide salts.
View Article and Find Full Text PDFTrafficking of intracellular cholesterol (Ch) to and into mitochondria of steroidogenic cells is required for steroid hormone biosynthesis. This trafficking is typically mediated by one or more proteins of the steroidogenic acute regulatory (StAR) family. Our previous studies revealed that 7-OOH, a redox-active cholesterol hydroperoxide, could be co-trafficked with Ch to/into mitochondria of MA-10 Leydig cells, thereby inducing membrane lipid peroxidation (LPO) which impaired progesterone biosynthesis.
View Article and Find Full Text PDFWhen selected tumor cells in a large in vitro population are exposed to ionizing radiation, they can send pro-survival signals to non-exposed counterparts (bystander cells). If there is no physical contact between irradiated and bystander cells, the latter respond to mediators from targeted cells that diffuse through the medium. One such mediator is known to be nitric oxide (NO).
View Article and Find Full Text PDFVarious studies have revealed that several cancer cell types can upregulate inducible nitric oxide synthase (iNOS) and iNOS-derived nitric oxide (NO) after moderate photodynamic treatment (PDT) sensitized by 5-aminolevulinic acid (ALA)-induced protoporphyrin-IX. As will be discussed, the NO signaled cell resistance to photokilling as well as greater growth and migratory aggressiveness of surviving cells. On this basis, it was predicted that diffusible NO from PDT-targeted cells in a tumor might enhance the growth, migration, and invasiveness of non- or poorly PDT-targeted bystander cells.
View Article and Find Full Text PDFEfficient direct air capture (DAC) of CO will require strategies to deal with the relatively low concentration in the atmosphere. One such strategy is to employ the combination of a CO -selective membrane coupled with a CO capture solvent acting as a draw solution. Here, the interactions between a leading water-lean carbon-capture solvent, a polyether ether ketone (PEEK)-ionene membrane, CO , and combinations were probed using advanced NMR techniques coupled with advanced simulations.
View Article and Find Full Text PDFWe report a new sodium fast-ion conductor, Na B S , that exhibits a high Na ion total conductivity of 0.80 mS cm (sintered pellet; cold-pressed pellet=0.21 mS cm ).
View Article and Find Full Text PDFThe search for new solid electrolyte materials and an understanding of fast-ion conductivity are crucial for the development of safe and high-power all-solid-state battery technology. Herein, we present the synthesis, structure, and properties of a crystalline lithium-ion conductor, LiAlPS (i.e.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2022
To increase catalytic efficiency, mesoporous supports have been widely applied to immobilize well-defined metal oxide clusters due to their ability to stabilize highly dispersed clusters. Herein, a redox-active heterometallic CeV-oxo cluster (CeV) was first presynthesized and then incorporated into mesoporous silica, SBA-15, via a straightforward impregnation method. Scanning transmission electron microscopy (STEM) and Fourier transform infrared spectroscopy (FTIR), in concert with scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), verified the successful introduction of the CeV cluster inside the pore of SBA-15.
View Article and Find Full Text PDFThe Overhauser effect is unique among DNP mechanisms in that it requires the modulation of the electron-nuclear hyperfine interactions. While it dominates DNP in liquids and metals, where unpaired electrons are highly mobile, Overhauser DNP is possible in insulating solids if rapid structural modulations are linked to a modulation in hyperfine coupling. Herein, we report that Overhauser DNP can be triggered by the strategic addition of a methyl group, demonstrated here in a Blatter's radical.
View Article and Find Full Text PDFSteroid hormone synthesis in steroidogenic cells requires cholesterol (Ch) delivery to/into mitochondria via StAR family trafficking proteins. In previous work, we discovered that 7-OOH, an oxidative stress-induced cholesterol hydroperoxide, can be co-trafficked with Ch, thereby causing mitochondrial redox damage/dysfunction. We now report that exposing MA-10 Leydig cells to Ch/7-OOH-containing liposomes (SUVs) results in (i) a progressive increase in fluorescence probe-detected lipid peroxidation in mitochondrial membranes, (ii) a reciprocal decrease in immunoassay-detected progesterone generation, and ultimately (iii) loss of cell viability with increasing 7-OOH concentration.
View Article and Find Full Text PDFSulfuric acid is a ubiquitous compound for industrial processes, and aqueous sulfate solutions also play a critical role as electrolytes for many prominent battery chemistries. While the thermodynamic literature on it is quite well-developed, comprehensive studies of the solvation structure, particularly molecular-scale dynamical and transport properties, are less available. This study applies a multinuclear nuclear magnetic resonance (NMR) approach to the elucidation of the solvation structure and dynamics over wide temperature (-10 to 50 °C) and concentration (0-18 M) ranges, combining the O shift, line width, and relaxation measurements, S shift and line width measurements, and H pulsed-field gradient NMR measurements of proton self-diffusivity.
View Article and Find Full Text PDFTumor cells exposed to stress-inducing radiotherapy or chemotherapy can send signals to non- or minimally exposed bystander cells. Bystander effects of ionizing radiation are well established, but little is known about such effects in non-ionizing photodynamic therapy (PDT). Our previous studies revealed that several cancer cell types upregulate inducible nitric oxide synthase (iNOS) and nitric oxide (NO) after a moderate 5-aminolevulinic acid (ALA)-based PDT challenge.
View Article and Find Full Text PDFDeveloping high-performance all-solid-state batteries is contingent on finding solid electrolyte materials with high ionic conductivity and ductility. Here we report new halide-rich solid solution phases in the argyrodite Li PS Cl family, Li PS Cl , and combine electrochemical impedance spectroscopy, neutron diffraction, and Li NMR MAS and PFG spectroscopy to show that increasing the Cl /S ratio has a systematic, and remarkable impact on Li-ion diffusivity in the lattice. The phase at the limit of the solid solution regime, Li PS Cl , exhibits a cold-pressed conductivity of 9.
View Article and Find Full Text PDFCancer Cell Microenviron
February 2017
Ionizing radiation of specifically targeted cells in a given population is known to elicit pro-death or pro-survival responses in non-targeted bystander cells, which often make no physical contact with the targeted ones. We have recently demonstrated a similar phenomenon for non-ionizing photodynamic therapy (PDT), showing that prostate cancer cells subjected to targeted photodynamic stress stimulated growth and migration of non-stressed, non-contacting bystander cells. Diffusible nitric oxide (NO) generated by stress-upregulated inducible nitric oxide synthase (iNOS) was shown to play a dominant role in these responses.
View Article and Find Full Text PDFThe bystander effects of anti-cancer ionizing radiation have been widely studied, but far less is known about such effects in the case of non-ionizing photodynamic therapy (PDT). In the present study, we tested the hypothesis that photodynamically-stressed prostate cancer PC3 cells can elicit nitric oxide (NO)-mediated pro-growth/migration responses in non-stressed bystander cells. A novel approach was used whereby both cell populations existed on a culture dish, but made no physical contact with one other.
View Article and Find Full Text PDFAccurate modeling of Li-ion batteries performance, particularly during the transient conditions experienced in automotive applications, requires knowledge of electrolyte transport properties (ionic conductivity κ, salt diffusivity D, and lithium ion transference number t(+)) over a wide range of salt concentrations and temperatures. While specific conductivity data can be easily obtained with modern computerized instrumentation, this is not the case for D and t(+). A combination of NMR and MRI techniques was used to solve the problem.
View Article and Find Full Text PDFWe resolve an existing discrepancy between convincing evidence for competing order in underdoped cuprates and spectroscopic data consistent with a homogeneous d-wave superconductor in the very same compounds. Specifically, we show that fluctuations of the competing order generate strongly inhomogeneous states whose spectra are almost indistinguishable from the pure d-wave superconductor. This is in contrast to the commonly studied case of homogeneously coexisting order, which typically generates a reconstructed Fermi surface with closed Fermi pockets.
View Article and Find Full Text PDFIsr J Psychiatry Relat Sci
November 1995
The new Israeli "Treatment of the Mentally Ill Law--1991" pays much attention to the protection of patients from unnecessary hospitalization in mental hospitals and to defining the rights and duties of patients who have been hospitalized, whether voluntarily or involuntarily. The question, however, is whether the rights of the public to be protected from dangerous patients were not sacrificed for the sake of the protection of the rights of the individual patient. The new law protects the rights of the patient in two main ways.
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