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Globally, billions of people burn fuels indoors for cooking and heating, which contributes to millions of chronic illnesses and premature deaths annually. Additionally, residential burning contributes significantly to black carbon emissions, which have the highest global warming impacts after carbon dioxide and methane. In this study, we use Fourier transform infrared spectroscopy (FTIR) to analyze fine-particulate emissions collected on Teflon membrane filters from 15 cookstove types and 5 fuel types. Emissions from three fuel types (charcoal, kerosene, and red oak wood) were found to have enough FTIR spectral response for functional group (FG) analysis. We present distinct spectral profiles for particulate emissions of these three fuel types. We highlight the influential FGs constituting organic carbon (OC) using a multivariate statistical method and show that OC estimates by collocated FTIR and thermal–optical transmittance (TOT) are highly correlated, with a coefficient determination of 82.5 %. As FTIR analysis is fast and non-destructive and provides complementary FG information, the analysis method demonstrated herein can substantially reduce the need for thermal–optical measurements for source emissions. [ABSTRACT FROM AUTHOR]

Globally, billions of people burn fuels indoors for cooking and heating, which contributes to millions of chronic illnesses and premature deaths annually. Additionally, residential burning contributes significantly to black carbon emissions, which have the highest global warming impacts after carbon dioxide and methane. In this study, we use Fourier transform infrared spectroscopy (FTIR) to analyze fine particulate emissions collected on Teflon membrane filters from fifteen cookstove types and five fuel types. Emissions from three fuel types (charcoal, kerosene, and red oak wood) were found to have enough FTIR spectral response for functional group (FG) analysis. We present distinct spectral profiles for particulate emissions of these three fuel types. We highlight the influential FGs constituting organic carbon (OC) using a multivariate statistical method and show that OC estimates by collocated FTIR and thermal optical transmittance (TOT) are highly correlated, with a coefficient of determination of 82.5%. As FTIR analysis is fast, non-destructive, and provides complementary FG information, the analysis method demonstrated herein can substantially reduce the need for thermal-optical measurements for source emissions. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants associated with negative health impacts. Assessments of tubing-related measurement bias for volatile PFAS are lacking, as gas-wall interactions with tubing can delay quantification of gas-phase analytes. We use online iodide chemical ionization mass spectrometry measurements to characterize tubing delays for three gas-phase oxygenated PFAS − 4:2 fluorotelomer alcohol (4:2 FTOH), perfluorobutanoic acid (PFBA), and hexafluoropropylene oxide dimer acid (HFPO-DA). Perfluoroalkoxy alkane and high-density polyethylene tubing yielded relatively short absorptive measurement delays, with no clear dependence on tubing temperature or sampled humidity. Sampling through stainless steel tubing led to prolonged measurement delays due to reversible adsorption of PFAS to the tubing surface, with strong dependence on tubing temperature and sample humidification. Silcosteel tubing afforded shorter measurement delays than stainless steel due to diminished surface adsorption of PFAS. Characterizing and mitigating these tubing delays is crucial for reliable quantification of airborne PFAS. Implications: Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants. Many PFAS are sufficiently volatile to exist as airborne pollutants. Measurements and quantification of airborne PFAS can be biased from material-dependent gas-wall interactions with sampling inlet tubing. Thus, characterizing these gas-wall interactions are crucial for reliably investigating emissions, environmental transport, and fates of airborne PFAS. [ABSTRACT FROM AUTHOR]

To investigate the role of nonsurgical management in the treatment of orbital cellulitis complicated by subperiosteal abscess (SPA) in adolescent and adult populations. A retrospective cohort study to assess the demographic, clinical, and outcome profiles of adolescent and adult patients with orbital SPA treated nonsurgically versus those who received surgical intervention. Primary outcome measures included hospitalization length and best-corrected visual acuity (BCVA) in the final evaluation. The study comprised 76 patients diagnosed with SPA in the setting of orbital cellulitis. Twelve were stratified into the nonsurgical cohort, while 64 represented the surgical group. Sinusitis was the most prevalent risk factor among both populations, and the rate did not differ significantly. SPA was located medially at a significantly higher rate in the nonsurgical cohort compared with the surgical. No patients in the nonsurgical population had a relative afferent pupillary defect (RAPD) on presentation. The proportion of patients who received adjunctive systemic corticosteroid therapy was comparable in both groups. Hospitalization length was significantly higher in the surgery cohort. BCVA in the final evaluation was favourable in both groups. Sinusitis subgroup analysis including eight nonsurgical patients produced overall consistent results. Findings from the largest study of orbital cellulitis complicated by SPA to date demonstrate a role for nonsurgical management in adolescent and adult patients who present with a medial SPA and/or ophthalmic examination without an RAPD. Among these populations, visual prognosis is favourable whether management includes surgical debridement or not, and surgical intervention may not predict a shorter duration of hospitalization. [ABSTRACT FROM AUTHOR]

Optical coherence tomography angiography (OCTA) is an emerging non-invasive technique for imaging the retinal vasculature. While there are many promising clinical applications for OCTA, determination of image quality remains a challenge. We developed a deep learning-based system using a ResNet152 neural network classifier, pretrained using ImageNet, to classify images of the superficial capillary plexus in 347 scans from 134 patients. Images were also manually graded by two independent graders as a ground truth for the supervised learning models. Because requirements for image quality may vary depending on the clinical or research setting, two models were trained—one to identify high-quality images and one to identify low-quality images. Our neural network models demonstrated outstanding area under the curve (AUC) metrics for both low quality image identification (AUC = 0.99, 95%CI 0.98–1.00, κ = 0.90) and high quality image identification (AUC = 0.97, 95%CI 0.96–0.99, κ = 0.81), significantly outperforming machine-reported signal strength (AUC = 0.82, 95%CI 0.77–0.86, κ = 0.52 and AUC = 0.78, 95%CI 0.73–0.83, κ = 0.27 respectively). Our study demonstrates that techniques from machine learning may be used to develop flexible and robust methods for quality control of OCTA images. [ABSTRACT FROM AUTHOR]

Aim: The Inventory of Psychotic‐Like Anomalous Self‐Experiences (IPASE) is a self‐report measure of minimal self‐disturbance. The aim of the current report was to assess the construct validity of the scale by examining its convergent validity with the gold‐standard measure of minimal self‐disturbance, the Examination of Anomalous Self‐Experience (EASE), and its discriminant validity. Method: The sample consisted of 46 participants (21 ultra‐high risk for psychosis patients, 14 first episode psychosis patients, 11 healthy controls). Correlations between the clinical instruments were examined. Results: The IPASE correlated strongly with general psychopathology and positive psychotic symptoms, moderately with negative symptoms, and weakly with manic symptoms. The strongest correlation (r = 0.92) was apparent between IPASE and EASE total scores. Conclusion: These preliminary data indicate construct validity of the IPASE, demonstrating both convergent and discriminant validity. The IPASE may be suitable as a screener measure for minimal self‐disturbance, but should not be used as a replacement to measure the construct of minimal self‐disturbance, which requires considerable psychopathological sophistication. [ABSTRACT FROM AUTHOR]

The prevalence of very elderly patients (aged 85 years and older) with visually significant cataracts continues to rise in the United States. We conducted a focused review of literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to investigate the impact of very old age on cataract surgery outcomes. The studies suggest that very elderly patients, relative to their younger counterparts, had similar complication rates after adjusting for their higher rates of age-related ocular and systemic comorbidities. In addition, most very elderly patients gained improvement in visual acuity, enjoyed increased quality of life, and had survival rates that extend beyond 1 year after surgery. Although many of the studies were small and lacked statistical power to exclude clinically important differences in outcome, findings generally supported cataract surgery in the very elderly. Further studies are required to augment evidence-based surgical decision-making in elderly persons with ocular comorbidities and visually significant cataracts. [ABSTRACT FROM AUTHOR]

Sphenoid sinus mucoceles (SSMs) are rare, benign lesions that can expand, often presenting with ocular symptoms—decreased vision, diplopia, visual field defects, proptosis, and external ophthalmoplegia. Reported cases are few, visual compromise varies, and factors affecting visual prognosis are poorly characterized. We investigate whether prompt surgical intervention (within 2 weeks of visual symptom onset) affects best-corrected visual acuity (BCVA) regained in patients with vision loss secondary to compressive SSM. We present a retrospective review of three cases and published literature to date. Our primary outcome was BCVA regained after surgical intervention; secondary outcomes included change in visual field defect and ophthalmological symptoms other than vision loss. Our three cases of SSM varied in onset, ranging from several hours to several months with patients aged from 13 to 80 years. All patients had severe vision loss to light perception (LP) or worse. Rapid neuro-imaging and urgent surgical intervention improved vision to count fingers at best. Of the two patients who underwent prompt decompression, one improved from no LP to LP and the other did not recover any vision. The patient who had visual loss for 3 months before intervention improved from LP to 20/400. Findings from our literature search, which yielded 12 cases of urgent intervention, supported the variability in visual prognosis despite prompt surgical intervention. SSMs are rare, pathologically benign lesions which can expand to cause ocular involvement. Prompt diagnosis and surgical decompression are recommended, but visual recovery may be limited even with urgent intervention. [ABSTRACT FROM AUTHOR]

Neurogenesis is a highly-regulated process occurring in the dentate gyrus that has been linked to learning, memory, and antidepressant efficacy. MicroRNAs (miRNAs) have been previously shown to play an important role in the regulation of neuronal development and neurogenesis in the dentate gyrus via modulation of gene expression. However, this mode of regulation is both incompletely described in the literature thus far and highly multifactorial. In this study, we designed sensors and detected relative levels of expression of 10 different miRNAs and found miR-338-3p was most highly expressed in the dentate gyrus. Comparison of miR-338-3p expression with neuronal markers of maturity indicates miR-338-3p is expressed most highly in the mature neuron. We also designed a viral “sponge” to knock down in vivo expression of miR-338-3p. When miR-338-3p is knocked down, neurons sprout multiple primary dendrites that branch off of the soma in a disorganized manner, cellular proliferation is upregulated, and neoplasms form spontaneously in vivo. Additionally, miR-338-3p overexpression in glioblastoma cell lines slows their proliferation in vitro. Further, low miR-338-3p expression is associated with increased mortality and disease progression in patients with glioblastoma. These data identify miR-338-3p as a clinically relevant tumor suppressor in glioblastoma. [ABSTRACT FROM AUTHOR]

While a rare ophthalmic pathogen, infections from Exophilia spp. are increasingly identified and have been associated with catastrophic vision loss. In this case report we present a previously undescribed manifestation of the melanin-producing fungus Exophilia Phaeomuriformis to the lower eyelid, establish an effective treatment, and review related cases. Previous cases of ophthalmic E. Phaeomuriformis were confined to the cornea and included iatrogenic tissue trauma. This case shares neither associations however includes a remote SJS history that likely led to changes in conjunctival tissue integrity. Previous cases of Exophilia spp. infecting the eyelid both included surgical source control and adjuvant antibiotic. In this case, topical therapy was deferred due to SJSrelated ocular cicatricial disease. Fortunately, a full resolution was achieved with surgical resection and oral antifungal treatment. [ABSTRACT FROM AUTHOR]

Thyroid eye disease (TED), an autoimmune inflammatory disorder of the orbit, presents with a potential array of clinical sequelae. The pathophysiology behind TED has been partially characterized in the literature. There remain certain elusive mechanisms welcoming of research advances. Disease presentation can vary, but those that follow a characteristic course start mild and increase in severity before plateauing into an inactive phase. Diagnosis and evaluation include careful physical examination, targeted laboratory work up, appropriate imaging studies, and tailored treatment regimens. Special consideration may apply to certain populations, such as pediatric and pregnant patients. [ABSTRACT FROM AUTHOR]

Anti-vascular endothelial growth factor (anti-VEGF) drugs - ranibizumab, aflibercept, and off-label bevacizumab - are vital to the treatment of common retinal diseases, including exudative age-related macular degeneration (AMD), diabetic macular edema (DME), and macular edema (ME) associated with retinal vein occlusion (RVO). Given the high prevalence of AMD and retinal vascular diseases, anti-VEGF agents represent a large cost burden to the United States (US) healthcare system. Although ranibizumab and aflibercept are 30-fold more expensive per injection than bevacizumab, the two more costly medications are commonly used in the US, even though all three have been shown to be effective and safe for treatment of these retinal diseases. We investigated the availability and content of professional ophthalmic guidelines on cost consideration in the selection of anti-VEGF agents. We found that current professional guidelines were limited in availability and lacked specific guidance on cost-based anti-VEGF drug selection. This represents a missed opportunity to encourage the practice of value-based medicine. [ABSTRACT FROM AUTHOR]

The Na+:HCO3- co-transporter NBC1 (SLC4A4, variant A, kidney specific) is located exclusively on the basolateral membrane of epithelial cells, implying that this molecule has acquired specific signals for targeting to the basolateral membrane. A motif with the sequence QQPFLS (positions 1010-1015) in the cytoplasmic tail of NBC1 was recently demonstrated to mediate targeting of NBC1 to the basolateral membrane. Here, we demonstrate that mutating the amino acid F (phenylalanine) or L (leucine) at positions 1013 or 1014 to alanine, respectively, resulted in the retargeting of NBC1 to the apical membrane. Further- more, mutation of the FL motif to FF showed similar properties as the wild-type; however, mutation of the FL motif to LL showed significant intracellular retention of NBC1. Mutating the amino acids Q-Q-P and S (positions 1010-1011-1012 and 1015) to A-A-A and A, respectively, did not affect the membrane targeting of NBC1. Functional studies in oocytes with microelectrode demonstrated that the apically targeted mutants, as well as basolaterally targeted mutants, are all functional. We propose that the FL motif in the COOH-terminal tail of NBC1 is essential for the targeting of NBC1 to the basolateral membrane but is distinct from the membrane-targeting di-leucine motif identified in other membrane proteins. [ABSTRACT FROM AUTHOR]

Periorbital oedema (POE), a condition with vision-impairing potential, is an adverse effect of several immunotherapies. As the utilization of immunotherapeutic agents continues to expand in cancer treatment, the number of patients with iatrogenic POE will increase. We thank Narez Hafez, MD, for his significant contributions to the patient's care, including the initiation of topical 2.5% phenylephrine therapy and oncologic treatment. [Extracted from the article]

PurposeMethodsResultsConclusionsThe aim of this study was to assess predictors and outcomes of subperiosteal abscess (SPA) management in adolescents and adults at two tertiary care centers.This retrospective cohort study included cases of SPA from January 1 2000 to October 9 2022 at two institutions. Patients 9 years or older were categorized into surgical and nonsurgical cohorts. Surgical subgroups included those who underwent functional endoscopic sinus surgery (FESS) alone, external (transcutaneous or transconjunctival) orbitotomy alone, or combined FESS and external surgery. The presented features were assessed as potential treatment predictors. Outcomes included length of stay (LOS), final best-corrected visual acuity (BCVA), readmission rate, and reoperation rate.Of the 159 SPA cases included, 127 (79.9%) underwent surgery and 32 (20.1%) were managed nonsurgically. The nonsurgical cohort was younger (p = .003) with smaller abscesses (p < .001) that were more likely to be medial (p < .001). The nonsurgical cohort had shorter LOS (p < .001); final BCVA and readmission rates were similarly favorable. Abscess location was correlated with surgical approach. Superior SPA that underwent FESS or external surgery alone had higher reoperation rates (57.1.0% and 58.3%, respectively) than combined (17.9%). External approach and FESS alone resulted in lower reoperation rates (15.4% and 15.0%, respectively) than combined (27.3%) for medial SPA. Subgroup analysis in the sinusitis cohort yielded similar results.A trial of nonsurgical management may be safe and effective for select patients aged 9 years and older with sinusitis-derived, medial, and small SPA. When surgery is indicated, approach should be guided by abscess location to minimize reoperation risk. [ABSTRACT FROM AUTHOR]

The capability of planar rRNA-based oligonucleotide microarrays for single-base-pair discrimination was evaluated using an approach that compares the non-equilibrium dissociation profiles and dissociation temperatures (Tds) of all probe-target duplexes simultaneously. Three sets of 16S rRNA gene specific probes at different levels of specificity were used along with their counter probes for individual sets having either one or two mismatches (MM) to their targets at specific external (next to terminus) and various internal positions. Criteria based on the Td approach and a discrimination index (DI) were proven to be competent in discriminating PM from internal MM duplexes, but not always for external MM duplexes. Maximal DI for separating PM duplexes from ones with two and one internal MM usually occurred at temperatures approximately 5–10°C and 10–15°C, respectively, higher than the Tds of the PM duplexes. Washing buffer type and salt concentration, and MM number and position were shown statistically to affect dissociation profiles, Td, and single-base-pair discriminating capability. The reusability potential of the planar microchip was further demonstrated. [ABSTRACT FROM AUTHOR]

Purpose: In vitro coagulation effects of bevacizumab, a drug with potential risks for severe hemorrhagic and arterial thromboembolic events (ATEs), are unknown. The aim of this study was to evaluate the effects of bevacizumab, including the common ophthalmic dose of 1.25 mg, on the coagulation cascade. Methods: Bevacizumab doses of 0.25, 0.5, 1.0, 1.25, 2.0, 2.5, and 4.0 mg were incubated at 37°C in the presence of pooled normal plasma (PNP) to determine its biological activity via activated partial thromboplastin time (aPTT) and prothrombin time (PT) at 30 min, 1 h, and 2 h. The control consisted of 40% normal saline and 60% PNP. All evaluations were conducted in triplet. Coagulation at each time point was compared with the control group by analysis of variance with Tukey's post hoc test. A P value of ≤0.05 was considered significant. Results: Mean bevacizumab aPTT ranged from 38.4 to 43.9 s, 37.4 to 43.1 s, and 39.0 to 43.2 s at 30 min, 1 h, and 2 h, respectively. Mean bevacizumab PT ranged from 15.7 to 16.8 s at 30 min, 14.6 to 16.2 s at 1 h, and 14.0 to 15.8 s at 2 h. For the control, aPTT was similar over time (40.1, 40.0, and 40.5 s), while PT decreased from 16.5 at 30 min to 15.4 s at 2 h. Bevacizumab decreased PT significantly at 2 h, compared with the PNP control, for the following doses: 0.25 mg [difference between means 1.04 s, 95% confidence interval (CI) 0.12-1.96], 1.25 mg (1.16 s, 95% CI 0.16-2.15), 2.5 mg (0.94 s, 95% CI 0.02-1.86), and 4 mg (1.41 s, 95% CI 0.41-2.40). Significant differences were not observed in PT at 30 min and 1 h as compared with controls. For all doses of bevacizumab, aPTT did not vary from controls at the 3 measured times. Conclusions: A common ophthalmic dose of bevacizumab 1.25 mg significantly increased in vitro coagulation. Further examination of the impact of ophthalmic bevacizumab on coagulation is warranted to provide insight into any putative link between ophthalmic bevacizumab and the risk for severe ATEs. [ABSTRACT FROM AUTHOR]

The article discusses the use of virtual reality (VR) simulators for many graduate medical education (GME) programs. It states that the GME programs had accessed to virtual eye surgery training with the systematic analysis of simulation training outcomes. It also notes that the simulation-based course requires construct validation by comparing surgical performance on the simulator between novices and ophthalmologists.

Virtual reality (VR) surgery simulation is an emerging teaching tool to train residents in cataract surgery. The widespread adoption of virtual surgery has been limited, however, by high costs and the absence of standardized curricula and evidence demonstrating the impact of VR training on resident surgical outcomes. We outline a resident virtual cataract surgery course-freely accessible online-that we hope will contribute to the development of a standardized VR cataract surgery curriculum. [ABSTRACT FROM AUTHOR]

During thermal processes utilized in affixing fluoropolymer coatings dispersion to fibers and fabrics, coating components are vaporized. It is suspected that per- and polyfluoroalkyl substances (PFAS) from the dispersions may undergo chemical transformations at the temperatures used, leading to additional emitted PFAS thermal byproducts. It is important to characterize these emissions to support evaluation of the resulting environmental and health impacts. In this study, a bench-scale system was built to simulate this industrial process via thermal application of dispersions to fiberglass utilizing relevant temperatures and residence times in sequential drying, baking, and sintering steps. Experiments were performed with two commercially available dispersions and a simple model mixture containing a single PFAS (6:2 fluorotelomer alcohol [6:2 FTOH]). Vapor-phase emissions were sampled and characterized by several off-line and real-time mass spectrometry techniques for targeted and nontargeted PFAS. Results indicate that multiple PFAS thermal transformation products and multiple nonhalogenated organic species were emitted from the exit of the high temperature third (sintering) furnace when 6:2 FTOH was the only PFAS present in the aqueous mixture. This finding supports the hypothesis that temperatures typical of these industrial furnaces may also induce chemical transformations within the fluorinated air emissions. Experiments using the two commercial fluoropolymer dispersions indicate air emissions of part-per-million by volume (ppmv) concentrations of heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether (Fluoroether E1), as well as other PFAS at operationally relevant temperatures. We suspect that E1 is a direct thermal decomposition product (via decarboxylation) of 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid (commonly referred to as HFPO-DA) present in the dispersions. Other thermal decomposition products, including the monomer, tetrafluoroethene, may originate from the PFAS used to stabilize the dispersion or from the polymer particles in suspension. This study represents the first researcher-built coating application simulator to report nontargeted PFAS emission characterization, real-time analyses, and the quantification of 30 volatile target PFAS. Implications: Thermal processes used to affix fluoropolymers to fabrics are believed to be a source of PFAS air emissions. These coating operations are used by many large and small manufacturers and typically do not currently require any air emissions control. This research designed and constructed a bench-scale system that simulates these processes and used several off-line and advanced real-time mass spectroscopy techniques to characterize PFAS air emissions from two commercial fluoropolymer dispersions. Further, as the compositions of commercial dispersions are largely unknown, a model three-component solution containing a single PFAS was used to characterize emissions of multiple PFAS thermal transformation products at operationally relevant conditions. This research shows that fluoropolymer fabric coating facilities can be sources of complex mixtures of PFAS air emissions that include volatile and semivolatile PFAS present in the dispersions, as well as PFAS byproducts formed by the thermal transformation of fluorocarbon and hydrocarbon species present in these dispersions. [ABSTRACT FROM AUTHOR]

Heart disease continues to be the leading cause of death in the United States. The demand for cardiovascular bypass procedures increases annually. Expanded polytetrafluoroethylene is a popular material for replacement implants, but it does have drawbacks such as high thrombogenicity and low patency, particularly in small diameter grafts. Hyaluronan, a naturally occurring polysaccharide in the human body, is known for its wound healing and anticoagulant properties. In this work, we demonstrate that treating the luminal surface of expanded polytetrafluoroethylene grafts with hyaluronan improves hemocompatibility without notably changing its mechanical properties and without significant cytotoxic effects. Surface characterization such as ATR-FTIR and contact angle goniometry demonstrates that hyaluronan treatment successfully changes the surface chemistry and increases hydrophilicity. Tensile properties such as elastic modulus, tensile strength, yield stress and ultimate strain are unchanged by hyaluronan enhancement. Durability data from flow loop studies demonstrate that hyaluronan is durable on the expanded polytetrafluoroethylene inner lumen. Hemocompatibility tests reveal that hyaluronan-treated expanded polytetrafluoroethylene reduces blood clotting and platelet activation. Together our results indicate that hyaluronan-enhanced expanded polytetrafluoroethylene is a promising candidate material for cardiovascular grafts. [ABSTRACT FROM AUTHOR]

IsdB is a receptor on the surface of the bacterial pathogen Staphylococcus aureus that extracts heme from hemoglobin (Hb) to enable growth on Hb as a sole iron source. IsdB is critically important both for in vitro growth on Hb and in infection models and is also highly up-regulated in blood, serum, and tissue infection models, indicating a key role of this receptor in bacterial virulence. However, structural information for IsdB is limited.We present here a crystal structure of a complex between human Hb and IsdB. In this complex, the α subunits of Hb are refolded with the heme displaced to the interface with IsdB. We also observe that atypical residues of Hb, His58 and His89 of αHb, coordinate to the heme iron, which is poised for transfer into the heme-binding pocket of IsdB. Moreover, the porphyrin ring interacts with IsdB residues Tyr440 and Tyr444. Previously, Tyr440 was observed to coordinate heme iron in an IsdB·heme complex structure. A Y440F/Y444F IsdB variant we produced was defective in hemetransfer yetformeda stablecomplexwithHb(Kd=6±2μM) in solution with spectroscopic features of the bis-His species observed in the crystal structure. Haptoglobin binds to a distinct site onHbto inhibit heme transfer to IsdB and growth of S. aureus, and a ternary complex of IsdB·Hb·Hp was observed. We propose a model for IsdB heme transfer from Hb that involves unfolding of Hb and heme iron ligand exchange. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are a unique class of chemicals synthesized to aid in industrial processes, fire-fighting products, and to benefit consumer products such as clothing, cosmetics, textiles, carpets, and coatings. The widespread use of PFAS and their strong carbon-fluorine bonds has led to their ubiquitous presence throughout the world. Airborne transport of PFAS throughout the atmosphere has also contributed to environmental pollution. Due to the potential environmental and human exposure concerns of some PFAS, research has extensively focused on water, soil, and organismal detection, but the presence of PFAS in the air has become an area of growing concern. Methods to measure polar PFAS in various matrices have been established, while the investigation of polar and nonpolar PFAS in air is still in its early development. This literature review aims to present the last two decades of research characterizing PFAS in outdoor and indoor air, focusing on active and passive air sampling and analytical methods. The PFAS classes targeted and detected in air samples include fluorotelomer alcohols (FTOHs), perfluoroalkane sulfonamides (FASAs), perfluoroalkane sulfonamido ethanols (FASEs), perfluorinated carboxylic acids (PFCAs), and perfluorinated sulfonic acids (PFSAs). Although the manufacturing of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) has been largely phased out, these two PFAS are still often detected in air samples. Additionally, recent estimates indicate that there are thousands of PFAS that are likely present in the air that are not currently monitored in air methods. Advances in air sampling methods are needed to fully characterize the atmospheric transport of PFAS. [Display omitted] • 85 papers detected PFAS in indoor and outdoor air from 2002 to 2022. • FTOHs, FASAs, and FASEs are the PFAS classes most frequently detected in air. • Most studies have used high volume-active air sampling to measure PFAS in air. • Novel air sampling methods are needed to characterize emerging PFAS. [ABSTRACT FROM AUTHOR]

Background: Effective control of schistosomiasis remains a challenging problem for endemic areas of the world. Given knowledge of the biology of transmission and past experience with mass drug administration (MDA) programs, it is important to critically evaluate the likelihood that MDA programs will achieve substantial reductions in Schistosoma prevalence. In implementing the World Health Organization Roadmap for Neglected Tropical Diseases it would useful for policymaking to model projections of the status of Schistosoma control in MDA-treated areas in the next 5-10 years. Methods: Calibrated mathematical models were used to project the effects of different frequency and coverage of MDA for schistosomiasis haematobia control in present-day endemic communities, taking into account uncertainties of parasite biology and input data. The modeling approach in this analysis was the Stratified Worm Burden model developed in our earlier works, calibrated using data from longitudinal S. haematobium control trials in Kenya. Results: Model-based simulations of MDA control in typical low-risk and higher-risk communities indicated that infection prevalence can be substantially reduced within 10 years only when there is a high degree of community participation (>70 %) with at least annual MDA. Significant risk for re-emergence of infection remains if MDA is suspended. Conclusions: In a stable (stationary) ecosystem, Schistosoma reproduction and transmission are sufficiently robust that the process of human infection continues, even under pressure from aggressive MDA. MDA alone is unlikely to interrupt transmission, and once mass treatment is suspended, the prevalence of human infection is likely to rebound to pre-control levels over a period of 25-30 years. MDA success in achieving very low levels of infection prevalence is highly dependent on treatment coverage and frequency within the local human population, and requires that both adults and children be included in drug delivery coverage. Ultimately, supplemental snail control and significant improvements in sanitation will be required to achieve full control of schistosomiasis by elimination of ongoing Schistosoma transmission. [ABSTRACT FROM AUTHOR]

Background: A seasonal transmission environment including seasonal variation of snail population density and human-snail contact patterns can affect the dynamics of Schistosoma infection and the success of control interventions. In projecting control outcomes, conventional modeling approaches have often ignored seasonality by using simplified intermediate-host modeling, or by restricting seasonal effects through use of yearly averaging.Methods: We used mathematical analysis and numerical simulation to estimate the impact of seasonality on disease dynamics and control outcomes, and to evaluate whether seasonal averaging or intermediate-host reduction can provide reliable predictions of control outcomes. We also examined whether seasonality could be used as leverage in creation of effective control strategies.Results: We found models that used seasonal averaging could grossly overestimate infection burden and underestimate control outcomes in highly seasonal environments. We showed that proper intraseasonal timing of control measures could make marked improvement on the long-term burden reduction for Schistosoma transmission control, and we identified the optimal timing for each intervention. Seasonal snail control, implemented alone, was less effective than mass drug administration, but could provide additive impact in reaching control and elimination targets.Conclusions: Seasonal variation makes Schistosoma transmission less sustainable and easier to control than predicted by earlier modeling studies. [ABSTRACT FROM AUTHOR]

When subjected to loads, granular materials tend to yield and exhibit some localized particle reorganizations. Due to the complex disordered structure of granular materials, it is challenging to identify the key preexisting defects in the static, unloaded structure that eventually promotes dynamical particle rearrangements once a load is applied. Here, based on discrete element simulations of an archetypal frictional granular material model, we introduce a machine learning framework that pinpoints such structural defects with unprecedented accuracy. We show that the optimal structural fingerprint of plastic flow defects depends on strain, wherein the plastic flow is governed by short-range defects at low strain but become dominated by medium-range defects at high strain. [ABSTRACT FROM AUTHOR]

The NH2 terminus of the sodium-bicarbonate cotransporter 1 (NBCe1) plays an important role in its targeting to the plasma membrane. To identify the amino acid residues that contribute to the targeting of NBCe1 to the plasma membrane, polarized MDCK cells were transfected with expression constructs coding for green fluorescent protein (GFP)-tagged NBCe1 NH2-terminal deletion mutants, and the localization of GFP-tagged proteins was analyzed by confocal microscopy. Our results indicate that the amino acids between residues 399 and 424 of NBCe1A contain important sequences that contribute to its localization to the plasma membrane. Site-directed mutagenesis studies showed that GFP-NBCe1A mutants D405A and D416A are retained in the cytoplasm of the polarized MDCK epithelial cells. Examination of functional activities of D405A and D416A reveals that their activities are reduced compared with the wild-type NBCe1A. Similarly, aspartic acid residues 449 and 460 of pancreatic NBCe1 (NBCe1B), which correspond to residues 405 and 416 of NBCe1A, are also required for its full functional activity and accurate targeting to the plasma membrane. In addition, while replacement of D416 with glutamic acid did not affect the targeting or functional activity of NBCe1A, substitution of D405 with glutamic acid led to the retention of the mutated protein in the intracellular compartment and impaired functional activity. These studies demonstrate that aspartic acid residues 405 and 416 in the NH2 terminus of NBCe1A are important in its accurate targeting to the plasma membrane. [ABSTRACT FROM AUTHOR]

Introduction: The distinction between the schizophrenia spectrum and other types of disorders may be clinically relevant in terms of its predictive validity as suggested by studies showing schizophrenia spectrum patients have more unfavourable outcomes compared to other psychotic disorders. The present study aimed to investigate whether basic self-disturbances and neurocognitive processes that have been linked to psychosis risk have discriminative power for schizophrenia spectrum disorders in patients presenting with first episode psychosis (FEP) and at ultra-high risk for psychosis (UHR).Methods: 38 FEP patients, 48 UHR patients, and 33 healthy controls were assessed for basic self-disturbances (using the Examination of Anomalous Self-Experience, EASE, interview), source monitoring and aberrant salience (behavioural tasks to measure neurocognitive constructs). Clinical groups were divided into patients with schizophrenia spectrum disorders and those with other non-spectrum disorders and were further compared on measures controlling for symptom severity and age.Results: Basic self-disturbances distinguished schizophrenia spectrum from non-spectrum disorders in the 'FEP only' sample, F = 19.76, p < 0.001, η2partial = 0.37, and also in the combined UHR/FEP sample, F = 23.56, p < 0.001, η2partial = 0.22. Additionally, some processes related to source monitoring deficits were elevated in schizophrenia spectrum disorders. In contrast, the two groups (schizophrenia spectrum vs other diagnoses) performed similarly in aberrant salience tasks. Comparable results were obtained for analyses performed with an FEP/UHR combined sample and the 'FEP only' sample.Discussion: Basic self-disturbances at the phenomenological level and source monitoring deficits on the neurocognitive level may be useful in identifying risk of schizophrenia spectrum disorders at the earliest clinical presentation. [ABSTRACT FROM AUTHOR]

Small modular reactors (SMRs) are currently being considered as future investments for commercial entities due to perceived advantages over traditional large-scale power reactors, particularly their considerably lower capital costs. One strategy for lowering the levelized cost of electricity (LCOE) of SMRs is to increase their burnup by utilizing high-assay low-enriched uranium (HALEU) fuels, which range from 5 to 20 weight percent (w/o) of U-235. By increasing fuel enrichment to HALEU levels, with higher specific fuel costs compared to standard enrichment, a plant may achieve an increased capacity factor by extending its fuel cycle and thereby reducing average yearly fuel supply costs. It is expected that the benefits of optimizing fuel enrichment to extend a reactor's fuel cycle outweigh the added cost due to more expensive fuel. In this paper, the net benefit of extending an SMR's fuel cycle by enriching uranium fuel to HALEU levels was estimated using 2017 nuclear fuel production market data with NuScale's 160 MWt SMR design as a case study. It was found that, for NuScale's design, plant LCOE decreased with increasing cycle length enabled by higher fuel enrichment. It was also observed that doubling cycle time from 24 months to 48 months netted each reactor a 1.23 $/MWh reduction in LCOE. The total savings for a 12-module SMR design were estimated to be around $5,840,000 per year. Therefore, utilizing HALEU fuel in SMRs can vastly improve their economic efficiency. [ABSTRACT FROM AUTHOR]

Background and Aims: The notion of basic self‐disturbance has been proposed as a core feature of schizophrenia‐spectrum disorders and as an indicator of future transition to psychosis in high‐risk populations. However, the relation of this notion to many clinical characteristics has not been explored. The aim of this study was: (a) to investigate the distribution of self‐disturbance and other symptoms dimensions in ultra‐high risk (UHR), first‐episode psychosis (FEP) and healthy control groups; and (b) to explore the association of self‐disturbance with a history of self‐harm, suicidal attempt, eating disorder symptomatology, school bullying victimization and sexual or physical abuse. Methods: Patients with UHR status (n = 38) or FEP (n = 26) and healthy controls (n = 33) were assessed with the Examination of Anomalous Self‐Experience (EASE) and the Comprehensive Assessment of at Risk Mental States (CAARMS). The clinical‐historical variables were assessed through medical records. Results: The FEP group scored significantly higher on the EASE than the UHR group, which scored significantly higher than the healthy control group, which had a very low score. Multivariate logistic regression analyses revealed that higher EASE score was significantly associated with a history of self‐harm, disordered eating and bullying victimization (but not with suicide attempts or sexual/physical abuse) after controlling for positive, negative and depressive symptoms. Conclusion: These novel findings suggest that self‐disturbance may be related to a history of school bullying victimization, self‐harm and eating disorder symptomatology in patients with or at‐risk of psychosis. If further confirmed, these findings are potentially relevant to clinical risk assessment and therapy. [ABSTRACT FROM AUTHOR]

• Performed double differential scattering cross section measurements for lucite. • Measured dynamic structure factor for lucite at VISION spectrometer. • Developed a new methodology for creation of thermal scattering libraries. • Produced a new improved thermal scattering library for lucite. With the advancements in technology (both experimental and computational) the determination of the"true" experimental phonon spectrum became more accessible. In this work a methodology for producing thermal scattering libraries from the experimental data (namely the DFT + oClimax method) for lucite (C 5 O 2 H 8) n is discussed. Double differential scattering cross section (DDSCS) experiments were performed at the Spallation Neutron Source of Oak Ridge National Laboratory (SNS ORNL). New scattering kernel evaluations, based on the phonon spectrum for (C 5 O 2 H 8) n ,were created using oClimax and NJOY2016 codes. In order to compare and asses the performance of the newly created library, the experimental setup was simulated using MCNP6.1. Compared to the current ENDF/B-VIII.0, the resulting RPI (C 5 O 2 H 8) n library improved the calculation of both double differential scattering and total scattering cross sections. A set of criticality benchmarks containing (C 5 O 2 H 8) n from HEU-MET-THERM resulted in an overall improved calculation of K eff . The DFT + oClimax method is shown to be the most comprehensive method for analysis of moderator materials, due to the fact that it can be verified against all data measured at VISION, ARCS and SEQUOIA neutron spectrometers at SNS ORNL, and experimental total scattering cross section measurements. This method also provides a new technique for calculating any phonon spectrum-related quantities such as scattering law kernel, specific heat capacity, thermal conductivity, etc. for any solid state material. [ABSTRACT FROM AUTHOR]

Improvements in determination of the thermal scattering law of moderator materials (measuring, calculating and validating) are important for accurate prediction of neutron thermalization in nuclear systems. In this work a methodology for producing thermal scattering libraries from the experimental data for polyethylene C 2 H 4 n is discussed. Double differential scattering cross section (DDSCS) experiments were performed at the Spallation Neutron Source of Oak Ridge National Laboratory (SNS ORNL). New scattering kernel evaluations, based on phonon spectrum for C 2 H 4 n , are created using the NJOY2016 code. Two different methods were used: direct and indirect geometry neutron scattering at ARCS and SEQUOIA, and VISION instruments, respectively, where the phonon spectrum was derived from the dynamical structure factor S(Q, ω ) obtained from the measured DDSCS. In order to compare and validate the newly created library, the experimental setup was simulated using MCNP6.1. Compared with the current ENDF/B-VII.1, the resulting RPI C 2 H 4 n libraries improved both double differential scattering and total scattering cross sections. A set of criticality benchmarks containing C 2 H 4 n from HEU-MET-THERM resulted in an overall improved calculation of K eff , although the libraries should be tested against benchmarks more sensitive to C 2 H 4 n . The DFT + oClimax method is used and is shown to be most comprehensive method for analysis of moderator materials. The importance of DFT + oClimax method lies in the fact that it can be validated against all data measured at VISION, ARCS and SEQUOIA, and experimental total scattering cross section measurements. [ABSTRACT FROM AUTHOR]

Background: Schistosoma parasites sustain a complex transmission process that cycles between a definitive human host, two free-swimming larval stages, and an intermediate snail host. Multiple factors modify their transmission and affect their control, including heterogeneity in host populations and environment, the aggregated distribution of human worm burdens, and features of parasite reproduction and host snail biology. Because these factors serve to enhance local transmission, their inclusion is important in attempting accurate quantitative prediction of the outcomes of schistosomiasis control programs. However, their inclusion raises many mathematical and computational challenges. To address these, we have recently developed a tractable stratified worm burden (SWB) model that occupies an intermediate place between simpler deterministic mean worm burden models and the very computationally-intensive, autonomous agent models. Methods: To refine the accuracy of model predictions, we modified an earlier version of the SWB by incorporating factors representing essential in-host biology (parasite mating, aggregation, density-dependent fecundity, and random egg-release) into demographically structured host communities. We also revised the snail component of the transmission model to reflect a saturable form of human-to-snail transmission. The new model allowed us to realistically simulate overdispersed egg-test results observed in individual-level field data. We further developed a Bayesian-type calibration methodology that accounted for model and data uncertainties. Results: The new model methodology was applied to multi-year, individual-level field data on S. haematobium infections in coastal Kenya. We successfully derived age-specific estimates of worm burden distributions and worm fecundity and crowding functions for children and adults. Estimates from the new SWB model were compared with those from the older, simpler SWB with some substantial differences noted. We validated our new SWB estimates in prediction of drug treatment-based control outcomes for a typical Kenyan community. Conclusions: The new version of the SWB model provides a better tool to predict the outcomes of ongoing schistosomiasis control programs. It reflects parasite features that augment and perpetuate transmission, while it also readily incorporates differences in diagnostic testing and human sub-population differences in treatment coverage. Once extended to other Schistosoma species and transmission environments, it will provide a useful and efficient tool for planning control and elimination strategies. [ABSTRACT FROM AUTHOR]

This study evaluated the grain size effect of Inconel 625 film against molten chloride salt. It is found that larger grain size Inconel 625 exhibits better corrosion resistance by reducing Cr depletion. ~ 2 nm surface NiO layer of Inconel 625 is incapable of compensating the negative effects from more initiation corrosion sites. Mo is the least likely leached element and its enrichment occurs in Cr-depleted regions as a result of Mo diffusion. Mg and Cl are two most seen salt elements in all corroded samples, while K and Na only attack Inconel 625 with the smallest grain size. • Grain size of Inconel 625 films grows with rising deposition temperature. • Larger grain size Inconel 625 possesses better corrosion performance. • Cr depletion is alleviated by increasing the grain size. • K and Na are only observed in the smallest grain size Inconel. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether nonagenarians relative to octogenarians are at increased risk of ocular complications from cataract surgery in the US Veterans Health Administration (VHA). Design: A retrospective cohort study. Participants: A total of 554 nonagenarians and 11 407 octogenarians who received cataract surgery in the VHA. Methods: Nonagenarians and octogenarians who received 1 cataract surgery without a second surgery within 90 days between October 1, 2005, and September 30, 2007, were identified using the National Patient Care Database (NPCD). Data collected include demographics, preoperative systemic and ocular comorbidities, intraoperative complications, and 90-day postoperative complications. The adjusted odds ratio (OR) of complications in nonagenarians using octogenarians as a reference group was calculated using logistic regression modeling. Main Outcome Measures: Intraoperative and postoperative ocular complications within 90 days of cataract surgery in nonagenarians versus octogenarians. Results: The most common systemic comorbidity for both age groups was diabetes mellitus (DM), and the most common ocular comorbidity for both age groups was age-related macular degeneration (AMD). Octogenarians had a higher prevalence of most systemic comorbidities, and nonagenarians had a higher prevalence of most ocular comorbidities. The most common intraoperative and postoperative complications for both age groups were vitreous loss or posterior capsular tear and posterior capsular opacification. The risk of having any intraoperative or postoperative complication was 13.5% for octogenarians and 13.4% for nonagenarians (P = 0.9001). The OR of having any intraoperative or postoperative complication in nonagenarians with octogenarians as a reference group was 0.94 (95% confidence interval, 0.73–1.22). Conclusions: Nonagenarians relative to octogenarians are not at increased risk of ocular complications from cataract surgery in the VHA. Further studies are needed to evaluate other outcome parameters, such as visual function and quality of life, in nonagenarians undergoing cataract surgery. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. [Copyright &y& Elsevier]

The sodium-bicarbonate cotransporter NBC1 is targeted exclusively at the basolateral membrane. Mutagenesis of a dihydrophobic FL motif (residues 1013-1014) in the C-terminal domain disrupts the targeting of NBC1. In the present study, we determined the precise constraints of the FL motif required for basolateral targeting of NBC1 by expressing epitope-tagged wild-type and mutant NBC1 in MDCK cells and RNA-injected Xenopus oocytes and examining their subcellular localization. We assayed the functional activity of the mutants by measuring bicarbonate-induced currents in oocytes. Wild-type NBC1 (containing PFLS) was expressed exclusively on the basolateral membrane in MDCK cells. Reversal of the FL motif (PLFS) had no effect on basolateral targeting or activity. Shifting the FL motif one residue upstream (FLPS) resulted in mistargeting of the apical membrane but the FLPS mutant retained its functional activity in oocytes. Shifting the FL motif one residue downstream resulted in a mutant (PSFL) that did not efficiently translocate to the plasma membrane and was instead colocalized with the ER marker, protein disulfide isomerase (PDI). Analysis of circular dichroism (CD) revealed that a short peptide, 20 amino acid residues, of wild-type NBC1 contained a significant alpha-helical structure, whereas peptides in which the FL motif was reversed or C-terminally shifted were disordered. We therefore propose that the specific orientation and the precise location of the FL motif in the primary sequence of NBC1 are strict requirements for the alpha-helical structure of the C-terminal cytoplasmic domain and for targeting of NBC1 to the basolateral membrane. [ABSTRACT FROM AUTHOR]

Thermal neutron scattering measurements of yttrium hydride from 5 to 1,200 K were conducted to determine the change in inelastic scattering as a function of temperature and to probe for anharmonic effects. Additionally, measurements on samples of YH x from x = 1.62 to 1.90 were done to determine the effects of varying hydrogen concentration on the inelastic spectra. Changes in temperature affected the inelastic spectra in unanticipated ways, indicating that there are anharmonic effects, whereas hydrogen concentration did not significantly affect the inelastic spectra. These measurements were compared against the ENDF/B-VIII.0 thermal scattering files of YH 2 , as well as new thermal scattering files created by using the stochastic temperature-dependent effective potential (s-TDEP). Both libraries were found to be in good agreement with the experimental data at lower temperatures. At higher temperatures, the s-TDEP method is better at predicting the experimentally observed softening of phonon modes in acoustic and optical regions. [ABSTRACT FROM AUTHOR]

A comprehensive study is presented of the characteristics of calcareous concretions in the Connecticut Valley varved clay (CVVC), a glacial lake sediment, probed by an array of investigations, including compositional analyses via X-ray powder diffraction and energy-dispersive X-ray spectroscopy, mechanical property mapping by nanoindentation, selective dissolution, microstructure examination by optical and electron microscopy, and stable isotope analyses, with an objective to resolve some long-standing questions on their origin and growth mechanisms. Results show that these concretions are of a biogenic origin and consist of ~40 wt% primary host sediments and ~ 60 wt% secondary calcite post-depositionally precipitated as pore infills and inter-particle cement. The highly consistent layering and dry density between the carbonate-free host sediments in the concretions and in-situ varved sediments manifest that the precipitated calcite causes no disturbance to the original stratification and structure of the varved sediments. Moreover, both the mechanical properties (i.e., Young's modulus and hardness) and calcite concentration in concretions exhibit a radially decreasing pattern slightly disturbed by the sediments' layered textures. Further supported by the radial distribution patterns of stable carbon and oxygen isotopes, the CVVC concretions grow in a concentric pattern. A conceptual ion transport model is proposed to further interpret the growth mechanisms. These concretions grow radially in a nearly closed sediment system with diffusion-controlled transport of HCO 3 − from decaying organic matter and Ca2+ from porewater at direction-dependent rates dominated by the pore characteristics of the local host sediments. The diverse concretion morphologies are attributed to the different growth rates in different directions affected by the heterogeneous layering and pore sizes of the host sediments. [Display omitted] • CVVC concretions consist of ~40 wt% CVVC sediments and ~ 60 wt% calcite. • Stable isotopes, mechanical properties, and calcite contents show radial patterns. • Concretions are of a biogenic origin and grew radially after deposition of the host. • The pores of the varved sediments significantly influence the concretion growth. • A conceptual ion transport model interprets the growth mechanisms. [ABSTRACT FROM AUTHOR]

Upon sustained loading, colloidal gels tend to feature delayed viscoplastic creep deformations. However, the relationship, if any, between the structure and creep dynamics of gels remains elusive. Here, based on accelerated molecular dynamics simulations and the recently developed softness approach (i.e., classification-based machine learning), we reveal that the propensity of a gel to exhibit long-time creep is encoded in its static, unloaded structure. By taking the example of a calcium–silicate–hydrate gel (the binding phase of concrete), we extract a local, non-intuitive structural descriptor (a revised version of the "softness" metric proposed by the pioneering work from Cubuk et al.) that is strongly correlated with the dynamics of the particles. Notably, the macroscopic creep rate exhibits an exponential dependence on the average softness. We find that creep results in a decrease in softness in the gel structure, which, in turn, explains the gradual decay of the creep rate over time. Finally, we demonstrate that the softness metric is strongly correlated with the average energy barrier that is accessible to the particles. [Display omitted] [ABSTRACT FROM AUTHOR]

Underwater cast and cured geopolymers with Si/Al ratios of 1.78 and 2.00, synthesized from Class C fly ash and metakaolin, were characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and unconfined compression, to understand the interactions between the geopolymer slurry and curing saline solutions and pertinent effects on its strength development. Slurries of geopolymers and Class G oil well cement were cast into porous molds that were immediately submerged into 0, 15, and 35 ppt saline solutions for 28 days curing, during which the pH of curing solutions was monitored. While the oil well cement exhibits a decreased compressive strength in high-salinity solutions, the strength of the two geopolymers increases with the curing solution's salinity. The underlying mechanisms are the chemical exchanges between the curing solution and geopolymer slurry, particularly the leaching or ingress of alkali ions (e.g., Na+, OH−) via diffusion, which depends upon the curing solution's salinity. • Geopolymer slurries were cast in porous molds and cured in saline solutions. • Strength of such cured geopolymers increases with curing solutions' salinity. • Oil well cement cured in the same conditions exhibits the opposite trend. • Curing solution and geopolymer slurry exchange alkali ions even before hardening. • Higher salinity prevents leaching of alkali ions from slurry into curing solution. [ABSTRACT FROM AUTHOR]

Here we report an innovative application of chronopotentiometry (CP) and potentiodynamic scan (PD) techniques to the measurement of redox potentials in a molten salt. Commonly, a stable Cl 2 /Cl− reference electrode is achieved by direct injection of chlorine gas to a graphite electrode, which requires rigorous design and operation for the high-temperature system to be studied. Instead, in situ techniques (CP and PD) were introduced to generate chlorine gas on the working graphite electrode, which then acts as the chlorine gas source. The measurements of formal potential and activity coefficient of AgCl/Ag at different AgCl mole fractions (X = 0.0039 and X = 0.0145) and temperatures (723–823 K) in molten LiCl-KCl salt were carried out using these two techniques. Moreover, these simple methods can be applied to measure the equilibrium potentials, formal potentials and activity coefficients of other metal chlorides in molten chloride salt as well as in other molten salt systems. • Cl 2 gas is produced by in-situ methods rather than by injecting Cl 2 gas. • CP & PD methods are safe and easy to operate with high accuracy and stability. • CP & PD methods can be applied in other salt systems to study the redox potential. [ABSTRACT FROM AUTHOR]