Visualization of Tetrahedral Li in the Alkali Layers of Li-Rich Layered Metal Oxides.

Understanding Li ion diffusion pathways in Li-rich layered transition metal (TM) oxides is crucial for understanding the sluggish kinetics in anionic O redox. Although Li diffusion within the alkali layers undergoes a low-barrier octahedral-tetrahedral-octahedral pathway, it is less clear how Li diffuses in and out of the TM layers, particularly given the complex structural rearrangements that take place during the oxidation of O. Here, we develop simultaneous electron ptychography and annular dark field imaging methods to unlock the Li migration pathways in LiNiMnCoO associated with structural changes in the charge-discharge cycle.

Vibrationally-resolved RIXS reveals OH-group formation in oxygen redox active Li-ion battery cathodes.

Vibrationally-resolved resonant inelastic X-ray scattering (VR-RIXS) at the O K-edge is emerging as a powerful tool for identifying embedded molecules in lithium-ion battery cathodes. Here, we investigate two known oxygen redox-active cathode materials: the commercial LiNiCoAlO (NCA) used in electric vehicles and the high-capacity cathode material LiNiCoMnO (LRNMC) for next-generation Li-ion batteries. We report the detection of a novel vibrational RIXS signature for Li-ion battery cathodes appearing in the O K pre-peak above 533 eV that we attribute to OH-groups.

Trapped O and the origin of voltage fade in layered Li-rich cathodes.

Oxygen redox cathodes, such as LiNiCoMnO, deliver higher energy densities than those based on transition metal redox alone. However, they commonly exhibit voltage fade, a gradually diminishing discharge voltage on extended cycling. Recent research has shown that, on the first charge, oxidation of O ions forms O molecules trapped in nano-sized voids within the structure, which can be fully reduced to O on the subsequent discharge.

Transition metal migration and O formation underpin voltage hysteresis in oxygen-redox disordered rocksalt cathodes.

Lithium-rich disordered rocksalt cathodes display high capacities arising from redox chemistry on both transition-metal ions (TM-redox) and oxygen ions (O-redox), making them promising candidates for next-generation lithium-ion batteries. However, the atomic-scale mechanisms governing O-redox behaviour in disordered structures are not fully understood. Here we show that, at high states of charge in the disordered rocksalt LiMnOF, transition metal migration is necessary for the formation of molecular O trapped in the bulk.

Evaluation of strategies to modify Anti-SARS-CoV-2 monoclonal antibodies for optimal functionality as therapeutics.

The current global COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a public health crisis with more than 168 million cases reported globally and more than 4.5 million deaths at the time of writing. In addition to the direct impact of the disease, the economic impact has been significant as public health measures to contain or reduce the spread have led to country wide lockdowns resulting in near closure of many sectors of the economy.

Pathogen Screening for Possible Causes of Meningitis/Encephalitis in Wild Carnivores From Saxony-Anhalt.

Inflammation in meninges and/or brain is regularly noticed in red foxes and other wild carnivores during rabies control programs. Despite negative rabies virus (RABV) results, the etiologies of these cases remain unknown. Thus, the aim of this study was to provide an overview of the occurrence of pathogens that may cause diseases in the brains of wild carnivores and pose a risk to humans and other animals.

A combination of two human neutralizing antibodies prevents SARS-CoV-2 infection in cynomolgus macaques.

Background: Human monoclonal antibody (mAb) treatments are promising for COVID-19 prevention or therapy. The pre-exposure prophylactic efficacy of neutralizing antibodies that are engineered with mutations to extend their persistence in human serum and the neutralizing antibody titer in serum required for protection against SARS-CoV-2 infection remain poorly characterized.

Methods: The Fc region of two neutralizing mAbs (COV2-2130 and COV2-2381) targeting non-overlapping epitopes on the receptor binding domain of SARS-CoV-2 spike protein was engineered to extend their persistence in humans and reduce interactions with Fc gamma receptors.

Covalency does not suppress O formation in 4d and 5d Li-rich O-redox cathodes.

Layered Li-rich transition metal oxides undergo O-redox, involving the oxidation of the O ions charge compensated by extraction of Li ions. Recent results have shown that for 3d transition metal oxides the oxidized O forms molecular O trapped in the bulk particles. Other forms of oxidised O such as O or (O-O) with long bonds have been proposed, based especially on work on 4 and 5d transition metal oxides, where TM-O bonding is more covalent.

Redox Chemistry and the Role of Trapped Molecular O in Li-Rich Disordered Rocksalt Oxyfluoride Cathodes.

In the search for high energy density cathodes for next-generation lithium-ion batteries, the disordered rocksalt oxyfluorides are receiving significant attention due to their high capacity and lower voltage hysteresis compared with ordered Li-rich layered compounds. However, a deep understanding of these phenomena and their redox chemistry remains incomplete. Using the archetypal oxyfluoride, LiMnOF, we show that the oxygen redox process in such materials involves the formation of molecular O trapped in the bulk structure of the charged cathode, which is reduced on discharge.

Overhead Mounted Optical Coherence Tomography in Childhood Glaucoma Evaluation.

Unlabelled: PRéCIS:: Overhead mounted spectral-domain optical coherence tomography (OCT) enables high-quality imaging of the optic nerve and macula in childhood glaucoma, and is particularly useful when standard tabletop OCT has failed or is not possible.

Purpose: Tabletop OCT, integral to adult glaucoma management, can be limited in childhood glaucoma patients because of young age, poor cooperation, and/or technical challenges. To address these imaging difficulties, we determined the feasibility and quality of an overhead mounted unit in childhood glaucoma.

Microvascular Features of Treated Retinoblastoma Tumors in Children Assessed Using OCTA.

Background And Objective: To describe the microvascular features of treated, clinically regressed, or reactivated retinoblastoma lesions using an investigational portable optical coherence tomography angiography (OCTA) system.

Patients And Methods: Single-center, prospective, cross-sectional, consecutive case-series of children with previously treated retinoblastoma who underwent portable OCTA of posterior retinoblastoma lesions.

Results: Eight tumors from seven eyes of five children with retinoblastoma were included.

Superstructure control of first-cycle voltage hysteresis in oxygen-redox cathodes.

In conventional intercalation cathodes, alkali metal ions can move in and out of a layered material with the charge being compensated for by reversible reduction and oxidation of the transition metal ions. If the cathode material used in a lithium-ion or sodium-ion battery is alkali-rich, this can increase the battery's energy density by storing charge on the oxide and the transition metal ions, rather than on the transition metal alone. There is a high voltage associated with oxidation of O during the first charge, but this is not recovered on discharge, resulting in reduced energy density.

Assessment of Macular Microvasculature in Healthy Eyes of Infants and Children Using OCT Angiography.

Purpose: To assess macular vasculature in healthy infants and children using OCT angiography (OCTA).

Design: Prospective cross-sectional study.

Participants: One hundred thirty-five normal maculae of 89 healthy infants and children (mean age, 8.

Home Tonometry Assists Glaucoma Drainage Device Management in Childhood Glaucoma.

Unlabelled: PRéCIS:: Home tonometry is useful in detecting tube-opening and alarming intraocular pressures (IOPs) after Baerveldt glaucoma drainage device (GDD) implantation in childhood glaucoma, allowing for timely physician response and individualized patient care.

Purpose: The postoperative management of the nonvalved Baerveldt GDD presents challenges in pediatric patients due to widely variable IOP often occurring perioperatively. We evaluated the use of home tonometry in the management of Baerveldt implants for refractory childhood glaucoma.

Optical Coherence Tomography Normative Peripapillary Retinal Nerve Fiber Layer and Macular Data in Children 0-5 Years of Age.

Purpose: To determine reference values for the peripapillary retinal nerve fiber layer (pRNFL) and macula in children 0-5 years of age.

Design: Prospective cross-sectional study.

Methods: This study was set in a single large academic pediatric ophthalmology practice.

Macular Microvascular Findings in Familial Exudative Vitreoretinopathy on Optical Coherence Tomography Angiography.

Background And Objective: To describe depth-resolved macular microvasculature abnormalities in patients with familial exudative vitreoretinopathy (FEVR) using optical coherence tomography angiography (OCTA).

Patients And Methods: Twenty-two eyes (11 eyes of six patients with FEVR and 11 control eyes) were imaged with OCTA. Graders qualitatively analyzed the OCTA images of the superficial and deep vascular complexes for abnormal vascular features and compared to fluorescein angiography (FA).

Hyperreflective Vitreous Opacities on Optical Coherence Tomography in a Patient With Bilateral Retinoblastoma.

An investigational, portable spectral-domain optical coherence tomography (SD-OCT) unit revealed small hyperreflective opacities in both eyes of a patient with bilateral retinoblastoma. There was no evidence of vitreous seeding on ophthalmoscopy of either eye. Although the opacities may initially raise concern for potential vitreous seeding, this report suggests alternate potential etiologies for such opacities, which were also seen on imaging of a cohort of normal eyes in pediatric patients.

Postoperative infection following strabismus surgery: case series and increased incidence in a single referral center.

Purpose: To identify and analyze cases of postoperative infection following strabismus surgery at a large referral center and to report the incidence, risk factors, and outcomes.

Methods: An electronic database search identified strabismus procedures at Duke Eye Center from July 1996 to October 2017. Diagnosis codes for periocular infections were used to further identify patients with possible infections following strabismus surgery.

Evaluating Cytokines in Immunotoxicity Testing.

One of the most powerful tools in immunotoxicology is the assessment of cytokines, the proteins/peptides responsible for regulating a variety of processes including immunity, inflammation, apoptosis, and hematopoiesis. Cytokine production measurements offer outstanding information and may eventually substitute for other more laborious procedures in the assessment of immunotoxicity. The particular profile of cytokine production provides indeed important information regarding the nature of many immunotoxic responses.

Oxygen redox chemistry without excess alkali-metal ions in Na[MgMn]O.

The search for improved energy-storage materials has revealed Li- and Na-rich intercalation compounds as promising high-capacity cathodes. They exhibit capacities in excess of what would be expected from alkali-ion removal/reinsertion and charge compensation by transition-metal (TM) ions. The additional capacity is provided through charge compensation by oxygen redox chemistry and some oxygen loss.