Chemical characteristics and water stability evaluation of groundwater in the CKDu Zone of Sri Lanka.

Groundwater is the main source of drinking water for the rural population in the chronic kidney disease of unknown etiology (CKDu) zone of the North Central Province (NCP) in Sri Lanka. In this study, a total of 334 groundwater samples (311 dug wells, 21 tube wells and 2 springs) during the wet season from two aquifers in the NCP were collected, and investigated their chemical characteristics and evaluate their water quality, including groundwater chemistry, main ion sources, the corrosion and scaling potential of groundwater. The results showed that the two hydrochemical types of groundwater in the NCP were mainly of the Ca-HCO, Na·Ca-HCO types, with the main HCO, Na and Ca ions in both types of groundwater originating from silicate and evaporite salt dissolution and influenced by alternating cation adsorption, while the presence of NO was mainly anthropogenic.

An assessment of beliefs about mental health care among community-based adults with severe, untreated alcohol use disorder.

Objective: Alcohol use disorder (AUD) is among the most prevalent substance use disorders in the USA. Despite availability of effective interventions, treatment initiation and engagement remain low. Existing interventions target motivation and practical barriers to accessing treatment among individuals established within treatment systems.

Quantum Diamonds at the Beach: Chemical Insights into Silica Growth on Nanoscale Diamond using Multimodal Characterization and Simulation.

Surface chemistry of materials that host quantum bits such as diamond is an important avenue of exploration as quantum computation and quantum sensing platforms mature. Interfacing diamond in general and nanoscale diamond (ND) in particular with silica is a potential route to integrate room temperature quantum bits into photonic devices, fiber optics, cells, or tissues with flexible functionalization chemistry. While silica growth on ND cores has been used successfully for quantum sensing and biolabeling, the surface mechanism to initiate growth was unknown.

PPAR agonists for the treatment of neuroinflammatory diseases.

Peroxisome proliferator-activated receptors [PPARs; PPARα, PPARβ/δ (also known as PPARδ), and PPARγ] widely recognized for their important role in glucose/lipid homeostasis, have recently received significant attention due to their additional anti-inflammatory and neuroprotective effects. Several newly developed PPAR agonists have shown high selectivity for specific PPAR isoforms in vitro and in vivo, offering the potential to achieve desired therapeutic outcomes while reducing the risk of adverse effects. In this review, we discuss the latest preclinical and clinical studies of the activation of PPARs by synthetic, natural, and isoform-specific (full, partial, and dual) agonists for the treatment of neuroinflammatory diseases, including HIV-associated neurocognitive disorders (HAND), Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and cerebral ischemia.

Scrutinizing formally Ni centers through the lenses of core spectroscopy, molecular orbital theory, and valence bond theory.

Nickel K- and L-edge X-ray absorption spectra (XAS) are discussed for 16 complexes and complex ions with nickel centers spanning a range of formal oxidation states from II to IV. K-edge XAS alone is shown to be an ambiguous metric of physical oxidation state for these Ni complexes. Meanwhile, L-edge XAS reveals that the physical d-counts of the formally Ni compounds measured lie well above the d count implied by the oxidation state formalism.

Lewis acid-assisted reduction of nitrite to nitric and nitrous oxides via the elusive nitrite radical dianion.

Reduction of nitrite anions (NO) to nitric oxide (NO), nitrous oxide (NO) and ultimately dinitrogen (N) takes place in a variety of environments, including in the soil as part of the biogeochemical nitrogen cycle and in acidified nuclear waste. Nitrite reduction typically takes place within the coordination sphere of a redox-active transition metal. Here we show that Lewis acid coordination can substantially modify the reduction potential of this polyoxoanion to allow for its reduction under non-aqueous conditions (-0.

Metastable Brominated Nanodiamond Surface Enables Room Temperature and Catalysis-Free Amine Chemistry.

Bromination of high-pressure, high-temperature (HPHT) nanodiamond (ND) surfaces has not been explored and can open new avenues for increased chemical reactivity and diamond lattice covalent bond formation. The large bond dissociation energy of the diamond lattice-oxygen bond is a challenge that prevents new bonds from forming, and most researchers simply use oxygen-terminated NDs (alcohols and acids) as reactive species. In this work, we transformed a tertiary-alcohol-rich ND surface to an amine surface with ∼50% surface coverage and was limited by the initial rate of bromination.

Quantifying the Steric Effect on Metal-Ligand Bonding in Fe Carbene Photosensitizers with Fe 2p3d Resonant Inelastic X-ray Scattering.

Understanding the electronic structure and chemical bonding of transition metal complexes is important for improving the function of molecular photosensitizers and catalysts. We have utilized X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) at the Fe L edge to investigate the electronic structure of two Fe N-heterocyclic carbene complexes with similar chemical structures but different steric effects and contrasting excited-state dynamics: [Fe(bmip)] and [Fe(btbip)], bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)pyridine and btbip = 2,6-bis(3-tert-butyl-imidazole-1-ylidene)pyridine. In combination with charge transfer multiplet and ab initio calculations, we quantified how changes in Fe-carbene bond length due to steric effects modify the metal-ligand bonding, including σ/π donation and π back-donation.

Oxygen K-edge X-ray absorption spectra of liquids with minimization of window contamination.

Oxygen K-edge X-ray absorption spectroscopy is used routinely to study a range of solid materials. However, liquid samples are studied less frequently at the oxygen K-edge due to the combined challenges of high-vacuum conditions and oxygen contamination of window materials. A modular sample holder design with a twist-seal sample containment system that provides a simple method to encapsulate liquid samples under high-vacuum conditions is presented.

Single-ion magnetism in the extended solid-state: insights from X-ray absorption and emission spectroscopy.

Large single-ion magnetic anisotropy is observed in lithium nitride doped with iron. The iron sites are two-coordinate, putting iron doped lithium nitride amongst a growing number of two coordinate transition metal single-ion magnets (SIMs). Uniquely, the relaxation times to magnetisation reversal are over two orders of magnitude longer in iron doped lithium nitride than other 3d-metal SIMs, and comparable with high-performance lanthanide-based SIMs.

Examining the molecular basis of coat color in a nocturnal primate family (Lorisidae).

Organisms use color for camouflage, sexual signaling, or as a warning sign of danger. Primates are one of the most vibrantly colored Orders of mammals. However, the genetics underlying their coat color are poorly known, limiting our ability to study molecular aspects of its evolution.

Saturation and self-absorption effects in the angle-dependent 2p3d resonant inelastic X-ray scattering spectra of Co.

Angle-dependent 2p3d resonant inelastic X-ray scattering spectra of a LaCoO single crystal and a 55 nm LaCoO film on a SrTiO substrate are presented. Theoretical calculation shows that, with ∼20 meV resolved Co 2p3d resonant inelastic X-ray scattering (RIXS), the excited states of the isotropic A(O) ground state are split by 3d spin-orbit coupling, which can be distinguished via their angular dependence. However, strong self-absorption and saturation effects distort the spectra of the LaCoO single crystal and limit the observation of small angular dependence.

Depth-dependent valence stratification driven by oxygen redox in lithium-rich layered oxide.

Lithium-rich nickel-manganese-cobalt (LirNMC) layered material is a promising cathode for lithium-ion batteries thanks to its large energy density enabled by coexisting cation and anion redox activities. It however suffers from a voltage decay upon cycling, urging for an in-depth understanding of the particle-level structure and chemical complexity. In this work, we investigate the LiNiMnCoO particles morphologically, compositionally, and chemically in three-dimensions.

Materializing rival ground states in the barlowite family of kagome magnets: quantum spin liquid, spin ordered, and valence bond crystal states.

The spin- kagome antiferromagnet is considered an ideal host for a quantum spin liquid (QSL) ground state. We find that when the bonds of the kagome lattice are modulated with a periodic pattern, new quantum ground states emerge. Newly synthesized crystalline barlowite (Cu(OH)FBr) and Zn-substituted barlowite demonstrate the delicate interplay between singlet states and spin order on the spin- kagome lattice.

Diabetes distress and HbA1c in racially/ethnically and socioeconomically diverse youth with type 1 diabetes.

Background: Diabetes distress, the emotional burden of caring for the chronic demands of diabetes, has not been well described in children and preadolescents with type 1 diabetes (T1D). This gap is particularly evident among youth of lower socioeconomic status (SES) and/or racial/ethnic minorities. Since these groups are more likely to have disparities in health outcomes and healthcare related to their diabetes, factors that could potentially improve glycemic and other diabetes-related outcomes should be studied closely.

X-ray absorption spectroscopy of organic sulfoxides.

Organic sulfoxides, a group of compounds containing the sulfinyl S[double bond, length as m-dash]O group, are widespread in nature, important in health and disease, and used in a variety of applications in the pharmaceutical industry. We have examined the sulfur K-edge X-ray absorption near-edge spectra of a range of different sulfoxides and find that their spectra are remarkably similar. Spectra show an intense absorption peak that is comprised of two transitions; a S 1s → (S-O)σ* and a S 1s → [(S-O)π* + (S-C)σ*] transition.

[(MeCN)Ni(CF)] and [Ni(CF)]: Foundations toward the Development of Trifluoromethylations at Unsupported Nickel.

Nickel anions [(MeCN)Ni(CF)] and [Ni(CF)] were prepared by the formal addition of 3 and 4 equiv, respectively, of AgCF to [(dme)NiBr] in the presence of the [PPh] counterion. Detailed insights into the electronic properties of these new compounds were obtained through the use of density functional theory (DFT) calculations, spectroscopy-oriented configuration interaction (SORCI) calculations, X-ray absorption spectroscopy, and cyclic voltammetry. The data collectively show that trifluoromethyl complexes of nickel, even in the most common oxidation state of nickel(II), are highly covalent systems whereby a hole is distributed on the trifluoromethyl ligands, surprisingly rendering the metal to a physically more reduced state.

Chemical control of competing electron transfer pathways in iron tetracyano-polypyridyl photosensitizers.

Photoinduced intramolecular electron transfer dynamics following metal-to-ligand charge-transfer (MLCT) excitation of [Fe(CN)(2,2'-bipyridine)] (), [Fe(CN)(2,3-bis(2-pyridyl)pyrazine)] () and [Fe(CN)(2,2'-bipyrimidine)] () were investigated in various solvents with static and time-resolved UV-Visible absorption spectroscopy and Fe 2p3d resonant inelastic X-ray scattering (RIXS). This series of polypyridyl ligands, combined with the strong solvatochromism of the complexes, enables the MLCT vertical energy to be varied from 1.64 eV to 2.

Barriers and Facilitators to Involvement in Children's Diabetes Management Among Minority Parents.

Objective: This study aimed to describe parents' perceptions of the factors that facilitate or are barriers to their involvement in children's type 1 diabetes (T1D) management among African American and Latino parents.

Methods: African American and Latino parents (N = 28) of 5- to 9-year-old children with T1D completed audio-recorded, semi-structured interviews that were transcribed and analyzed using thematic analysis. Themes were identified that aligned with the theoretically-derived Capability-Opportunity-Motivation-Behavior (COM-B) framework.

Site-Specific Structure at Multiple Length Scales in Kagome Quantum Spin Liquid Candidates.

Realizing a quantum spin liquid (QSL) ground state in a real material is a leading issue in condensed matter physics research. In this pursuit, it is crucial to fully characterize the structure and influence of defects, as these can significantly affect the fragile QSL physics. Here, we perform a variety of cutting-edge synchrotron X-ray scattering and spectroscopy techniques, and we advance new methodologies for site-specific diffraction and L-edge Zn absorption spectroscopy.

Soft X-ray spectroscopy with transition-edge sensors at Stanford Synchrotron Radiation Lightsource beamline 10-1.

We present results obtained with a new soft X-ray spectrometer based on transition-edge sensors (TESs) composed of Mo/Cu bilayers coupled to bismuth absorbers. This spectrometer simultaneously provides excellent energy resolution, high detection efficiency, and broadband spectral coverage. The new spectrometer is optimized for incident X-ray energies below 2 keV.