A simple method for floating graphene oxide films facilitates nanoscale investigations of ion and water adsorption.

Graphene oxide (GO) is a promising material for separations. Nanoscale GO thin films at the air/water interface are excellent experimental models to understand molecular-scale interactions of ions and water with GO. However, the characteristics of GO, such as functional groups and flake size, also affect the thin film properties making it difficult to make systematic studies with GO thin films. This paper reports a simple, reliable, and quick method of preparing ultra-thin GO films, irrespective of their origin, and demonstrates the new opportunities possible with the utilization of this method. The total amount of GO used to form the thin film is significantly less compared to previous examples in the literature, minimizing the dissolved GO in the subphase. X-ray reflectivity (XR) studies show that the majority of the GO film has 1.5 nm thickness over a macroscopic area (∼100 cm2) with very small roughness. Sum frequency generation (SFG) spectroscopy measurements show that H2O and D2O interact differently with GO films, a property that was not observed before. SFG data show that functional groups vary significantly between different commercially available GO samples. The differences are also characterized with XR at high resolution. X-ray fluorescence near total reflection (XFNTR) measurements show that these differences strongly affect ion adsorption and interfacial water behavior near GO, which are vital properties in separation applications. The results pave the way for future studies to elucidate the complex separation mechanisms with GO.

Unraveling pH-Dependent Changes in Adsorption Structure of Uranyl on Alumina (012).

Mitigating uranium transport in groundwater is imperative for ensuring access to clean water across the globe. Here, in situ resonant anomalous X-ray reflectivity is used to investigate the adsorption of uranyl on alumina (012) in acidic aqueous solutions, representing typical UVI concentrations of contaminated water near mining sites. The analyses reveal that UVI adsorbs at two distinct heights of 2.4-3.2 and 5-5.3 Å from the surface terminal oxygens. The former is interpreted as the mixture of inner-sphere and outer-sphere complexes that adsorb closest to the surface. The latter is interpreted as an outer-sphere complex that shares one equatorial H2O with the terminal surface oxygen. With increasing pH, we observe an increasing prevalence of these outer-sphere complexes, indicating the enhanced role of the hydrogen bond that stabilizes adsorbed uranyl species. The presented work provides a molecular-scale understanding of sorption of uranyl on Al-based-oxide surfaces that has implications for environmental chemistry and materials science.

Monovalent ion-graphene oxide interactions are controlled by carboxylic acid groups: Sum frequency generation spectroscopy studies.

Graphene oxide (GO) is a two-dimensional, mechanically strong, and chemically tunable material for separations. Elucidating GO-ion-water interactions at the molecular scale is highly important for predictive understanding of separation systems. However, direct observations of the nanometer region by GO surfaces under operando conditions are not trivial. Therefore, thin films of GO at the air/water interface can be used as model systems. With this approach, we study the effects of alkali metal ions on water organization near graphene oxide films at the air/water interface using vibrational sum frequency generation (SFG) spectroscopy. We also use an arachidic acid Langmuir monolayer as a benchmark for a pure carboxylic acid surface. Theoretical modeling of the concentration-dependent sum frequency signal from graphene oxide and arachidic acid surfaces reveals that the adsorption of monovalent ions is mainly controlled by the carboxylic acid groups on graphene oxide. An in-depth analysis of sum frequency spectra reveals at least three distinct water populations with different hydrogen bonding strengths. The origin of each population can be identified from concentration dependent variations of their SFG signal. Interestingly, an interfacial water structure seemed mostly insensitive to the character of the alkali cation, in contrast to similar studies conducted at the silica/water interface. However, we observed an ion-specific effect with lithium, whose strong hydration prevented direct interactions with the graphene oxide film.

Correction: Ion and water adsorption to graphene and graphene oxide surfaces.

Correction for 'Ion and water adsorption to graphene and graphene oxide surfaces' by Amanda J. Carr, et al., Nanoscale, 2023, https://doi.org/10.1039/d3nr02452k.

Ion and water adsorption to graphene and graphene oxide surfaces.

Graphene and graphene oxide (GO) are two particularly promising nanomaterials for a range of applications including energy storage, catalysis, and separations. Understanding the nanoscale interactions between ions and water near graphene and GO surfaces is critical for advancing our fundamental knowledge of these systems and downstream application success. This minireview highlights the necessity of using surface-specific experimental probes and computational techniques to fully characterize these interfaces, including the nanomaterial, surrounding water, and any adsorbed ions, if present. Key experimental and simulation studies considering water and ion structures near both graphene and GO are discussed. The major findings are: water forms 1-3 hydration layers near graphene; ions adsorb electrostatically to graphene under an applied potential; the chemical and physical properties of GO vary considerably depending on the synthesis route; and these variations influence water and ion adsorption to GO. Lastly, we offer outlooks and perspectives for these research areas.

Establishment and characterization of an iPSC line (UCLi023-A) derived from a Late-Onset Retinal Degeneration patient carrying a founder mutation in C1QTNF5.

Late-Onset Retinal Degeneration (L-ORD) is a rare autosomal dominant macular disease, with most cases being caused by a founder mutation in C1QTNF5. Initial symptoms, which generally occur during or after the sixth decade, include abnormal dark adaptation and changes in peripheral vision. Over time, the build-up of sub-retinal pigment epithelium (RPE) deposits leads to macular atrophy and bilateral central vision loss1. Here, we describe the generation of a human induced pluripotent stem cell (iPSC) line from dermal fibroblasts of a 61-year-old L-ORD Caucasian male patient carrying the founder mutation (c.489C>G, p.Ser163Arg), using episomal reprogramming.

Convenient Confinement: Interplay of Solution Conditions and Graphene Oxide Film Structure on Rare Earth Separations.

Graphene oxide (GO) membranes are excellent candidates for a range of separation applications, including rare earth segregation and radionuclide decontamination. Understanding nanoscale water and ion behavior near interfacial GO is critical for groundbreaking membrane advances, including improved selectivity and permeability. We experimentally examine the impact of solution conditions on water and lanthanide interactions with interfacial GO films and connect these results to GO membrane performance. The investigation of the confined films at the air-water interface with a combination of surface-specific spectroscopy and X-ray scattering techniques allows us to understand water and ion behaviors separately. Sum frequency generation spectroscopy reveals a dramatic change in interfacial water organization because of graphene oxide film deprotonation. Interfacial X-ray fluorescence measurements show a 17× increase in adsorbed lanthanide to the GO film from subphase pH 3 to pH 9. Liquid surface X-ray reflectivity data show an additional 2.7 e- per Å2 for GO films at pH 9 versus pH 3 as well. These results are connected to GO membrane performance, which show increased selectivity and decreased flux for membranes filtering pH 9 solutions. We posit insoluble lanthanide hydroxides form at higher pHs. Taken together, these results highlight the importance of interfacial experiments on model GO systems.

Facilitating Development of Problem-Solving Skills in Veterinary Learners with Clinical Examples.

This paper seeks to open discussion on the teaching of problem-solving skills in veterinary learners. We start by defining the term problem before discussing what constitutes problem-solving. For veterinary medical learners, problem-solving techniques are similar to those of decision-making and are integral to clinical reasoning. Problem-solving requires the veterinary learner to organize information logically to allow application of prior or new knowledge in arriving at a solution. The decision-making must encompass choices that provide the most beneficial and economical approach. In a modification of an existing protocol, we suggest the inclusion of the 5 elements: (1) define the problem list; (2) create an associated timeline; (3) describe the (anatomical) system involved or the pathophysiological principle applicable to the case; (4) propose management for the case; and (5) identify unique features of the case. During problem-solving activities, the instructor should take the role of facilitator rather than teacher. Skills utilized in the facilitation of problem-solving by learners include coaching, differential reinforcement, effective feedback, modelling and 'think out loud'. Effective feedback must inform learners of their progress and performance, as this is fundamental to continued learning and motivation to succeed. In order to put the above into context, we end with an example case scenario showing how we would approach the teaching of problem-solving to veterinary learners.

Investigation of PTC124-mediated translational readthrough in a retinal organoid model of AIPL1-associated Leber congenital amaurosis.

Leber congenital amaurosis type 4 (LCA4), caused by AIPL1 mutations, is characterized by severe sight impairment in infancy and rapidly progressing degeneration of photoreceptor cells. We generated retinal organoids using induced pluripotent stem cells (iPSCs) from renal epithelial cells obtained from four children with AIPL1 nonsense mutations. iPSC-derived photoreceptors exhibited the molecular hallmarks of LCA4, including undetectable AIPL1 and rod cyclic guanosine monophosphate (cGMP) phosphodiesterase (PDE6) compared with control or CRISPR-corrected organoids. Increased levels of cGMP were detected. The translational readthrough-inducing drug (TRID) PTC124 was investigated as a potential therapeutic agent. LCA4 retinal organoids exhibited low levels of rescue of full-length AIPL1. However, this was insufficient to fully restore PDE6 in photoreceptors and reduce cGMP. LCA4 retinal organoids are a valuable platform for in vitro investigation of novel therapeutic agents.

Effective Veterinary Clinical Teaching in a Variety of Teaching Settings.

This review explores different modalities for clinical teaching of veterinary learners globally. Effective clinical teaching aims to prepare graduates for a successful career in clinical practice. Unfortunately, there is scant literature concerning clinical teaching in veterinary medicine. Our intent for this review is to stimulate and/or facilitate discussion and/or research in this important area. We discuss the different forms that veterinary clinical teaching can take, depending on their setting, which can be university-based clinical activities, work-based in commercial clinical practices, or in a traditional academic setting with little to no real-time exposure to clients and patients. We suggest that each of these modalities has a place in clinical teaching of veterinary learners at any point in the curriculum but that a mix of these approaches will likely provide an improved experience for the learner. Further, we discuss strategies to improve clinical teaching in these different settings. Potential strategies related to the teaching skills of clinical instructors could include training in delivery of clinical teaching in a variety of learning settings, and instructors' official recognition, including opportunities for career progression. Potential strategies to improve clinical teaching in different teaching settings would vary with the learning settings. For example, in traditional academic settings, case-based learning with incorporation of simulation models is one proposed strategy. The involvement of learners in 'teach-others' is a strategy for both traditional academic and clinical settings. Finally, clearly addressing Day One competencies is required in any clinical teaching setting.

Trivalent ion overcharging on electrified graphene.

The structure of the electrical double layer (EDL) formed near graphene in aqueous environments strongly impacts its performance for a plethora of applications, including capacitive deionization. In particular, adsorption and organization of multivalent counterions near the graphene interface can promote nonclassical behaviors of EDL including overcharging followed by co-ion adsorption. In this paper, we characterize the EDL formed near an electrified graphene interface in dilute aqueous YCl3solution usingin situhigh resolution x-ray reflectivity (also known as crystal truncation rod) and resonant anomalous x-ray reflectivity (RAXR). These interface-specific techniques reveal the electron density profiles with molecular-scale resolution. We find that yttrium ions (Y3+) readily adsorb to the negatively charged graphene surface to form an extended ion profile. This ion distribution resembles a classical diffuse layer but with a significantly high ion coverage, i.e., 1 Y3+per 11.4 ± 1.6 Å2, compared to the value calculated from the capacitance measured by cyclic voltammetry (1 Y3+per ∼240 Å2). Such overcharging can be explained by co-adsorption of chloride that effectively screens the excess positive charge. The adsorbed Y3+profile also shows a molecular-scale gap (⩾5 Å) from the top graphene surfaces, which is attributed to the presence of intervening water molecules between the adsorbents and adsorbates as well as the lack of inner-sphere surface complexation on chemically inert graphene. We also demonstrate controlled adsorption by varying the applied potential and reveal consistent Y3+ion position with respect to the surface and increasing cation coverage with increasing the magnitude of the negative potential. This is the first experimental description of a model graphene-aqueous system with controlled potential and provides important insights into the application of graphene-based systems for enhanced and selective ion separations.

Using the Five-Microskills Method in Veterinary Medicine Clinical Teaching.

Effective clinical teaching is essential for the development of veterinary learners. Teaching clinical reasoning is a challenge for veterinary instructors as many lack adequate training in clinical teaching. In this paper, we propose the use of the five-microskills (FMS; also known as the one-minute preceptor) model of clinical teaching as a tool that can be used not only in teaching during clinical encounters but also during traditional teaching sessions (e.g., practicals). The FMS model assists the instructor in estimating the level of knowledge and development of the learner and allows for providing feedback. The FMS model is applicable in the busy clinical or teaching schedule of the instructor and requires training only of the instructor, not the learner. We provide two examples of the use of the FMS model, one of a clinical encounter and the other a biochemistry practical. From the examples, readers should be able to extract the basis of the model and start using it in their day-to-day practice. For proper use of the model, 1-4 h of training is usually recommended.

Parent-child interactions during joint engagement with touchscreen technology: A comparison of younger versus older toddlers.

With a plethora of touchscreen apps aimed at young children, parents are receiving mixed messages about the appropriateness of such technology for their toddlers. The American Academy of Pediatrics (2016) advises limited engagement with digital media for this age group and encourages parents to co-engage with children when they are using screens. However, very little is known about parent-child interaction in the context of joint engagement with digital screen media in the toddler years. This study observed 56 toddlers (M = 32.5 months old; 53 % female) and a parent (52 mothers; 4 fathers) performing a 3-minute drawing task on a touchscreen tablet (digital condition), and on an Etch-A-Sketch (non-digital condition) using a repeated measures design. Observations were analysed using global ratings of dyadic interaction, comparing warmth, cooperation and conflict between digital and non-digital conditions. A mixed MANCOVA analysis, controlling for levels of daily usage of touchscreens, revealed lower levels of parent-child cooperation and warmth in the digital condition compared to the non-digital condition. In addition, there was a main effect of age with younger dyads displaying less cooperation overall, particularly in the digital condition where interactions were also less warm. Results suggest that co-engaging with digital technology can be a challenging and potentially emotionally charged context for both parents and young children. Younger toddlers, especially, may be more likely to experience less cooperative interactions when co-engaging with digital technology with a parent. Results are discussed in relation to developmental differences between 2- and 3-year olds, and the need for more nuanced guidance for parents supporting young children's interaction with digital media.

Use of continuous cranial shape variation in the identification of divergent crocodile species of the genus Mecistops.

The discovery of cryptic biodiversity has blossomed under the advancements of genetic techniques, but species identification via morphology remains crucial to effective conservation efforts. In this study, we tested the use of continuous cranial shape variation in distinguishing the two living species of Mecistops: the West African slender-snouted crocodile (M. cataphractus) and the Central African slender-snouted crocodile (M. leptorhynchus). Using a combination of geometric morphometric characters and ratios of linear measurements, we identified statistically significant variation in cranial bone and overall skull shape of mature individuals that corroborates existing molecular and discrete morphological evidence for two distinct, extant species within Mecistops. Specifically, variation in the shape of the nasal appears particularly diagnostic, while ratios involving metrics of snout length to snout width at the premaxillary notch offer distinguishing features easily measured in the field. Because of the complementary results and applications of the morphometric and cranial ratio analyses, we argue that both methodologies remain relevant to species identification. Moreover, we recommend continued cooperation between geneticists and morphologists in diagnosing species of conservation concern.

Midline venous catheters as an alternative to central line catheter placement: a product evaluation.

Midline catheters have emerged as a successful alternative to peripheral venous catheters (PVCs) and central venous catheters (CVCs) in select patients. Midline catheters allow for greater duration of access when compared with PVCs and avoid the critical complications associated with CVCs. This article describes the implementation of the Powerwand® midline at a large paediatric tertiary care facility in acute and intensive care settings, and presents illustrative cases of the catheter in use. Product evaluation was performed by a paediatric vascular access team of registered nurses and included information on patient outcomes, inserter satisfaction, patient satisfaction, and cost effectiveness.

Bestrophinopathies: perspectives on clinical disease, Bestrophin-1 function and developing therapies.

Bestrophinopathies are a group of clinically distinct inherited retinal dystrophies that typically affect the macular region, an area synonymous with central high acuity vision. This spectrum of disorders is caused by mutations in bestrophin1 (BEST1), a protein thought to act as a Ca2+-activated Cl- channel in the retinal pigment epithelium (RPE) of the eye. Although bestrophinopathies are rare, over 250 individual pathological mutations have been identified in the BEST1 gene, with many reported to have various clinical expressivity and incomplete penetrance. With no current clinical treatments available for patients with bestrophinopathies, understanding the role of BEST1 in cells and the pathological pathways underlying disease has become a priority. Induced pluripotent stem cell (iPSC) technology is helping to uncover disease mechanisms and develop treatments for RPE diseases, like bestrophinopathies. Here, we provide a comprehensive review of the pathophysiology of bestrophinopathies and highlight how patient-derived iPSC-RPE are being used to test new genomic therapies in vitro.

Emulsions Stabilized by Inorganic Nanoclays and Surfactants: Stability, Viscosity, and Implications for Applications.

Pickering emulsions, or emulsions with solid particles at the interface, have attracted significant interest in Enhanced Oil Recovery (EOR) processes, cosmetics, and drug delivery systems due to their ability to resist coalescence. Here, a synthetic clay nanoparticle, laponite®, is utilized to create oil-in-water (o/w) emulsions, and the addition of small-molecule surfactants induces a more stable emulsion. In this study, the stability of laponite® Pickering emulsions with and without the surfactants (dodecyltrimethylammonium bromide (DTAB), Pluronic F68 (F68), and sodium dodecyl sulfate (SDS) is investigated using dynamic light scattering (DLS), ζ-potential, optical microscopy, and rheology. With laponite® and no added surfactants, the DLS and ζ-potential results show formation of emulsion droplets with a diameter of 3 µm and a ζ-potential of -90 mV. With the addition of surfactants, both the droplet diameter and ζ-potential increase, suggesting adsorption of surfactants on the surface of laponite® particle. Optical microscopy suggests that the Pickering emulsion without surfactant undergoes flocculation, while the emulsion becomes stable to coalescence and creaming with addition of surfactants due to formation of a network structure. Regardless of the formation of network structure, the laponite®-F68 emulsion rheologically behaves as a Newtonian fluid, while the laponite®-SDS and laponite®-DTAB emulsions display shear thinning behavior. The difference in the rheological behavior can be attributed to the weak adsorption of F68 on laponite® and electrostatic interactions between laponite® and charged surfactants at oil-water interface.

Annexin A8 regulates Wnt signaling to maintain the phenotypic plasticity of retinal pigment epithelial cells.

Wnt signalling mediates complex cell-cellinteractions during development and proliferation. Annexin A8 (AnxA8), a calcium-dependent phospholipid-binding protein, and canonical Wnt signalling mechanisms have both been implicated in retinal pigment epithelial (RPE) cell differentiation. The aim here was to examine the possibility of cross-talk between AnxA8 and Wnt signalling, as both are down-regulated upon fenretinide (FR)-mediated RPE transdifferentiation. AnxA8 suppression in RPE cells via siRNA or administration of FR induced neuronal-like cell transdifferentiation and reduced expression of Wnt-related genes, as measured by real-time PCR and western blotting. AnxA8 gene expression, on the other hand, remained unaltered upon manipulating Wnt signalling, suggesting Wnt-related genes to be downstream effectors of AnxA8. Co-immunoprecipitation revealed an interaction between AnxA8 and ß-catenin, which was reduced in the presence of activated TGF-ß1. TGF-ß1 signalling also reversed the AnxA8 loss-induced cell morphology changes, and induced ß-catenin translocation and GSK-3ß phosphorylation in the absence of AnxA8. Ectopic over-expression of AnxA8 led to an increase in active ß-catenin and GSK-3ß phosphorylation. These data demonstrate an important role for AnxA8 as a regulator of Wnt signalling and a determinant of RPE phenotype, with implications for regenerative medicine approaches that utilise stem cell-derived RPE cells to treat conditions such as age-related macular degeneration.

Dispersal and Land Cover Contribute to Pseudorabies Virus Exposure in Invasive Wild Pigs.

We investigated the landscape epidemiology of a globally distributed mammal, the wild pig (Sus scrofa), in Florida (U.S.), where it is considered an invasive species and reservoir to pathogens that impact the health of people, domestic animals, and wildlife. Specifically, we tested the hypothesis that two commonly cited factors in disease transmission, connectivity among populations and abundant resources, would increase the likelihood of exposure to both pseudorabies virus (PrV) and Brucella spp. (bacterial agent of brucellosis) in wild pigs across the Kissimmee Valley of Florida. Using DNA from 348 wild pigs and sera from 320 individuals at 24 sites, we employed population genetic techniques to infer individual dispersal, and an Akaike information criterion framework to compare candidate logistic regression models that incorporated both dispersal and land cover composition. Our findings suggested that recent dispersal conferred higher odds of exposure to PrV, but not Brucella spp., among wild pigs throughout the Kissimmee Valley region. Odds of exposure also increased in association with agriculture and open canopy pine, prairie, and scrub habitats, likely because of highly localized resources within those land cover types. Because the effect of open canopy on PrV exposure reversed when agricultural cover was available, we suggest that small-scale resource distribution may be more important than overall resource abundance. Our results underscore the importance of studying and managing disease dynamics through multiple processes and spatial scales, particularly for non-native pathogens that threaten wildlife conservation, economy, and public health.

Bestrophin1: A Gene that Causes Many Diseases.

Bestrophinopathies are a group of clinically distinct inherited retinal dystrophies that lead to the gradual loss of vision in and around the macular area. There are no treatments for patients suffering from bestrophinopathies, and no measures can be taken to prevent visual deterioration in those who have inherited disease-causing mutations. Bestrophinopathies are caused by mutations in the Bestrophin1 gene (BEST1), a protein found exclusively in the retinal pigment epithelial (RPE) cells of the eye. Mutations in BEST1 affect the function of the RPE leading to the death of overlying retinal cells and subsequent vision loss. The pathogenic mechanisms arising from BEST1 mutations are still not fully understood, and it is not clear how mutations in BEST1 lead to diseases with distinct clinical features. This chapter discusses BEST1, the use of model systems to investigate the effects of mutations and the potential to investigate individual bestrophinopathies using induced pluripotent stem cells.