The Hidden Influence: Impacts of Residual Dimethylformamide in NDSB‐211 on icIEF Separation for Monoclonal Antibodies

ABSTRACT Monoclonal antibodies (mAbs) present analytical challenges due to their inherent heterogeneity and susceptibility to post‐translational modifications (PTMs) during production and storage. Monitoring of charge heterogeneity profiles by imaged capillary isoelectric focusing (icIEF) has been aided by the use of non‐detergent sulfobetaines (NDSBs), particularly NDSB‐211, to enhance protein solubility and stability. When used in a quality control laboratory setting, NDSB‐211 has shown performance variability over time due to residual manufacturing impurities that impact the capillary isoelectric focusing separation. Dimethylformamide (DMF) was detected using 1 H nuclear magnetic resonance (NMR) in several lots of NDSB‐211 that simultaneously produced poor resolution of basic variants of a mAb on icIEF. A parallel spiking study using DMF at 1%–10% (v/v) on 1 H NMR and icIEF illustrates the interference in charge heterogeneity separation when a large amount of DMF is present in the NDSB‐211 reagent. As DMF is not found on the NDSB‐211 certificate of analysis from any vendor, more traditional additives for icIEF are suggested to limit the potential interference for analytical methods.

Characterizing Recent PDMS Changes in Electrokinetic‐Based Microfluidic Devices’ Performance and Manufacturing for Cell Sorting Applications

ABSTRACT Understanding cells from complex biological samples is vital to understanding cellular biology and medical applications. One evolving tool for cell sorting is the use of microfluidic devices to achieve higher precision and remove the need for labeling cell subpopulations. However, few microfluidic devices have been translated commercially beyond academic research often due to challenges in larger scale fabrication. Here, we initially investigated a compelling label‐free microfluidic device with complex geometries to perform contactless dielectrophoresis (cDEP) for applications in enriching cell subpopulations in oncology, neurology, stem cells, and sample preparation. We began scaling the manufacturing of cDEP devices using Dow Sylgard 184, more commonly referred to as PDMS (polydimethylsiloxane). However, we began observing a new, dynamic bubble formation phenomenon which had significant impacts on device performance. Within just 5 min of exposure at typical experimental values, cell death was nearly 100%. Variables related to manufacturing, environment, equipment, personnel, raw materials sourcing, lithography methods and experimental conditions/parameters were systematically evaluated to find the root cause of the exacerbated bubble formation observed. Further, alternate polymers were sourced for manufacturing and experimental performance comparisons. All variables investigated failed to solve the significant decline in device performance and increase in cell death. Upon completing chemical analysis in this work, we conclude that the decline in device performance was a direct result of changes to the expected PDMS properties and composition. Despite these challenges, our robust quality control combined with experimental protocols to remove bubbles from the cDEP devices achieved consistent experimental performance including 2–3 h run times and >90% cell viability after sorting. These new PDMS behaviors will need to continue to be monitored and controlled to ensure consistency in experimentation, application and commercialization feasibility for a wide variety of microfluidic device designs and applications.

Mitigation of Volatile Chemicals' Effect on Adjacent Microtiter Plate Wells

ABSTRACT In vitro new approach methodologies used to assess chemicals for biological effects are typically designed to limit the amount of test article required and to promote efficiencies such as compatibility with liquid handlers, and so forth. This is certainly true in the case of genetic toxicology, where many methods have been and continue to be developed with 96‐ or 384‐well plate processing in mind. However, one recognized concern with microwell plates is that the volatility of test substances and/or their metabolites and/or their degradation products may affect adjacent wells. Here, we describe an approach that combines breathable membranes as well as activated carbon filters to mitigate volatility issues in 96 well plates. These experiments were performed with cyclophosphamide‐ and trimethylhydroquinone‐exposed TK6 cells and utilized the biomarkers micronuclei, p53, γH2AX, phospho‐histone H3, and nuclei to counting bead ratios to both demonstrate volatility impact and to assess the effectiveness of the solution described herein.

Application of Biological Modifiers to a Multiplexed, Human Cell‐Based DNA Damage Assay Provides Mechanistic Information on Genotoxicity and Molecular Targets

ABSTRACT This laboratory has reported that the combined use of In Vitro MicroFlow and MultiFlow assays provides information regarding chemicals' genotoxic mode of action (MoA). In an effort to go beyond MoA assessments, we incorporated a panel of biological response modifiers that elicit specific effects on the assays' biomarker response profiles. This was done to pursue our hypothesis that such perturbation signatures would reveal information on clastogenic mechanisms and molecular targets. For this proof‐of‐concept study, we exposed TK6 cells to 20 known clastogens. Cells were exposed in 96‐well plates in the presence and absence of each of four modifying agents at one optimized concentration: talazoparib (PARP inhibitor), MK‐8776 (CHK1 inhibitor), AZD‐7648 (DNA‐PK inhibitor), or a cocktail of reactive oxygen species scavengers. In parallel, cells were also exposed to each of the test chemicals for 4 h, at which time cells were washed and allowed to recover for an additional 20 h. For each of these treatment conditions, sample processing and flow cytometric analyses were performed using standard In Vitro MicroFlow and MultiFlow procedures to measure micronuclei, γH2AX, phosphohistone‐H3 (p‐H3), p53 activation, and relative nuclei counts. The resulting biomarker response data were processed with PROAST benchmark dose (BMD) software, with modifying agent as a covariate. Unsupervised hierarchical clustering of the collective potency metrics for various combinations of biomarkers showed that clastogens with similar genotoxic mechanisms grouped together. Overall, this study shows that in combination with biological response modifiers, MultiFlow and In Vitro MicroFlow biomarkers can provide mechanistic insights into chemical‐induced genotoxicity.

Charging Ahead: The Evolution and Reliability of Nickel‐Zinc Battery Solutions

ABSTRACT Nickel‐Zinc (Ni‐Zn) batteries offer an interesting alternative for the expanding electrochemical energy storage industry due to their high‐power density, low cost, and environmental friendliness. However, significant reliability challenges such as capacity fading, self‐discharge, thermal instability, and electrode degradation detract from their competitiveness in the market, hindering their widespread adoption. This study thoroughly examines the degradation mechanisms and approaches to improve the reliability of Ni‐Zn batteries: Starting with their basic chemistry, operating principles, and degradation pathways, strategies for improvement are explored including material modification, electrolyte optimization, cell design approaches, and thermal management techniques. Advanced characterization methods for data collection and reliability assessment are discussed, including electrochemical, structural, spectroscopic, and in situ techniques which are noted for their ability to identify key areas of concern for this cell chemistry. We further consider emerging trends such as novel materials, hybridization with other energy technologies, and the challenges of large‐scale implementation, emphasizing the need for standardized reliability testing protocols. Opportunities for the integration of advanced sensing, such as fiber Bragg grating (FBG) sensors for real‐time monitoring and anomaly detection, along with machine learning (ML) and prognostics and health management of Ni‐Zn batteries are highlighted, as these open the door to future research directions. This comprehensive review should serve as a resource for researchers, engineers, and industry experts aiming to advance and commercialize dependable, high‐performing Ni‐Zn battery technology for a sustainable energy future.

Regional epilepsy: Unraveling the epileptic phenomenon

Ictal SPECT in hypothalamic lesions

Impact of length of stay on diagnostic yield in the epilepsy monitoring unit: A multi‐center retrospective 12‐year Veterans Health Administration study

Abstract Objective Epilepsy Monitoring Units (EMUs) in Veterans Health Administration (VHA) Epilepsy Centers of Excellence (ECoE) are critical for the diagnosis and management of seizure disorders. Whether a shorter length of stay (LOS) in the EMU due to scheduling impacts diagnostic yield is unclear. Methods Data from 7074 EMU visits across 15 VHA EMUs (2012–2024) were analyzed. Based on usual admission schedules, EMUs were divided into “fixed” (typically Monday–Friday) or “flexible” subgroups. Diagnostic outcomes were classified as epileptic seizures (ES), psychogenic non‐epileptic seizures (PNES), other non‐epileptic events, and inconclusive. Diagnostic rates were compared between fixed and flexible sites using cumulative distribution functions and other statistical tests. Readmission data for initially inconclusive cases were also examined. Results Diagnostic outcomes showed the following distribution: 23% ES, 19% PNES, 11% other non‐epileptic events, and 47% inconclusive. Similar distributions were seen between fixed and flexible sites, although a higher proportion of diagnostic admissions were completed earlier in fixed sites and over a longer average LOS at flexible sites. Admissions diagnostic of ES had longer LOS than all other outcomes (4.5 vs. 3.8 days, p  < 0.001). Repeat EMU admissions were performed in 10% of patients and were more likely to be diagnostic of ES than PNES or other non‐epileptic events. Significance About half of EMU admissions within VHA were non‐diagnostic with respect to the patients' typical clinical events. ES and PNES were observed at approximately similar rates, although the diagnosis of ES required a longer LOS. Fixed sites did not appear inferior to flexible sites for reaching diagnostic conclusions in our analysis. The higher proportion of earlier diagnoses at fixed sites observed was likely a statistical effect of their predefined shorter admission lengths. Further investigations of EMU resource utilization based on individual goals of monitoring are necessary to better examine and improve efficiency. Plain Language Summary Epilepsy Monitoring Units (EMUs) are specialized hospital units used to diagnose and characterize seizures. This study looked at over 7000 admissions across 15 Veterans Health Administration EMUs to see whether length of stay affected diagnosis rates based on admission scheduling and seizure types. Regardless of whether patients were admitted on a fixed schedule (Monday–Friday) or a flexible schedule, about half of hospitalizations did not capture typical events. Diagnosis of epileptic seizures and psychogenic non‐epileptic seizures occurred at similar rates, though diagnosing epileptic seizures took longer. Findings suggest fixed (shorter) hospital stays may be as effective as longer flexible hospitalizations.

From Disordered Eating to Eating Competence: Exploring Transitions in Adolescent Eating Profiles and the Role of Identity, Embodiment, and Critical Eating Messages From Parents and Peers

ABSTRACT Objective Adolescence is a key period for the development of eating behaviours. To date, little attention has been paid to the development of positive eating behaviours during adolescence, and longitudinal research with such a holistic focus is lacking. To provide a better understanding of adolescent eating behaviours, this study examined patterns of stability and change in eating profiles among community youth. In addition, this study examined how these profiles and patterns were related to background, psychological, and contextual variables. Method and Results This longitudinal study with two timepoints included 608 adolescents and emerging adults at the first timepoint for the current analyses (T1: 64.3% female; M age  = 16.99; SD = 1.24; range = 14–21 years). Using latent transition analysis (LTA), three eating behaviour profiles emerged: a competent eating profile, a subclinical profile, and a clinical profile. Although most individuals in the competent eating and clinical profiles remained within their profile over time, individuals in the subclinical profile were more likely to progress toward greater eating competence or more severe eating disorder symptoms. Using multinomial logistic regression models; sex, adjusted BMI, identity, embodiment, and critical parent and peer eating messages appeared to be related to profile membership, whereas only age, sex, and adjusted BMI were related to transition patterns. Conclusion The present study informs theory and practice by identifying subgroups of adolescents who differ in their eating behaviours. In addition, these findings provide insight into which aspects are meaningfully related to stability and variability in eating behaviours, supporting the development of targeted interventions.

Quantitative geomorphic analysis of vegetated dunes of Western Pampa plain of Argentina: The role of aeolian legacy and hydroclimatic variability in landscape evolution

Abstract The temperate grassland and cultivated soils of the Western Pampa of Argentina, southern South America, developed over Late Pleistocene–Holocene aeolian sands, shifted from semiarid to dry subhumid in the past ~120 years with an increase of precipitation variability, concordant with significant changes in agricultural land use. This Western Pampean Dunefield (WPD) is a dormant system, mostly stabilised by vegetation and agriculture, with extensive reactivations during the 1930s ‘Pampas Dust Bowl’ and the current formation of new dunes in an anthropogenically disturbed landscape. Analysis of the complex assembled aeolian landforms of the WPD with quantification of vegetated dunes provides new associations for landscape evolution and aims to contribute to science‐based land management. The methodology includes field surveys, remote sensing imagery, dune morphometry, site stratigraphy and optically stimulated luminescence (OSL) dating. Main aeolian bedforms are blowout dunes and sinuous ridges, associated with aeolian streaks, sand sheets and fluvial‐aeolian plains. The blowout dunes (simple, compound and complex) reach tens to thousands of meters in diameter, have commonly superimposed dunes on the depositional lobes, and sand transport directions towards the NW, NNW‐NNE and SW. The sinuous ridges, continuous for 100s m to 1–2 km, have nearly symmetrical profiles and two main crest orientations (NW‐SE and SW–NE). Cross‐dune patterns and associated OSL chronology allow proposing a morphostratigraphy scheme of compound and complex blowout dunes developed during the Late Pleistocene and growing since then, while sinuous ridges probably accreted in the Holocene. Young blowout dunes are penecontemporaneous and post‐date sinuous ridges, reflecting significant aeolian reworking processes. Patches of barchanoid and reversing dunes superimposed on blowout dunes, which have been active since at least the CE 1970s, and the new dune formation in the past two decades, often in intensively cultivated areas, indicate that synergistic biogeomorphic processes may yield irreversible changes in semi‐arid to dry subhumid landscapes with an aeolian legacy.