Scanning Electrochemical Microscopy Reveals That Model Silicon Anodes Demonstrate Global Solid Electrolyte Interphase Passivation Degradation during Calendar Aging.

Silicon is a promising next-generation anode to increase energy density over commercial graphite anodes, but calendar life remains problematic. In this work, scanning electrochemical microscopy was used to track the site-specific reactivity of a silicon thin film surface over time to determine if undesirable Faradaic reactions were occurring at the formed solid electrolyte interphase (SEI) during calendar aging in four case scenarios: formation between 1.5 V and 100 mV with subsequent rest starting at (1) 1.5 V and (2) 100 mV and formation between 0.75 V and 100 mV with subsequent rest starting at (3) 0.75 V and (4) 100 mV. In all cases, the electrical passivation of silicon decreased with increasing time and potential relative to Li/Li+ over a 3 day period. Along with the decrease in passivation, the homogeneity of passivation over a 500 µm2 area decreased with time. Despite some local "hot spots" of reactivity, the areal uniformity of passivation suggests global SEI failure (e.g., SEI dissolution) rather than localized (e.g., cracking) failure. The silicon delithiated to 1.5 V vs Li/Li+ was less passivated than the lithiated silicon (at the beginning of rest, the forward rate constants, kf, for ferrocene redox were 7.19 × 10-5 and 3.17 × 10-7 m/s, respectively) and was also found to be more reactive than the pristine silicon surface (kf of 5 × 10-5 m/s). This reactivity was likely the result of SEI oxidation. When the cell was only delithiated up to 0.75 V versus Li/Li+, the surface was still passivating (kf of 6.11 × 10-6 m/s), but still less so than the lithiated surface (kf of 3.03 × 10-9 m/s). This indicates that the potential of the anode should be kept at or below ∼0.75 V vs Li/Li+ to prevent decreasing SEI passivation. This information will help with tuning the voltage windows for prelithiation in Si half cells and the operating voltage of Si full cells to optimize calendar life. The results provided should encourage the research community to investigate chemical, rather than mechanical, modes of failure during calendar aging and to stop using the typical convention of 1.5 V as a cutoff potential for cycling Si in half cells.

Advanced Electroanalysis for Electrosynthesis.

Electrosynthesis is a popular, environmentally friendly substitute for conventional organic methods. It involves using charge transfer to stimulate chemical reactions through the application of a potential or current between two electrodes. In addition to electrode materials and the type of reactor employed, the strategies for controlling potential and current have an impact on the yields, product distribution, and reaction mechanism. In this Review, recent advances related to electroanalysis applied in electrosynthesis were discussed. The first part of this study acts as a guide that emphasizes the foundations of electrosynthesis. These essentials include instrumentation, electrode selection, cell design, and electrosynthesis methodologies. Then, advances in electroanalytical techniques applied in organic, enzymatic, and microbial electrosynthesis are illustrated with specific cases studied in recent literature. To conclude, a discussion of future possibilities that intend to advance the academic and industrial areas is presented.

CRISPR-Cas9-assisted genome editing in E. coli elevates the frequency of unintended mutations.

Cas-assisted lambda Red recombineering techniques have rapidly become a mainstay of bacterial genome editing. Such techniques have been used to construct both individual mutants and massive libraries to assess the effects of genomic changes. We have found that a commonly used Cas9-assisted editing method results in unintended mutations elsewhere in the genome in 26% of edited clones. The unintended mutations are frequently found over 200 kb from the intended edit site and even over 10 kb from potential off-target sites. We attribute the high frequency of unintended mutations to error-prone polymerases expressed in response to dsDNA breaks introduced at the edit site. Most unintended mutations occur in regulatory or coding regions and thus may have phenotypic effects. Our findings highlight the risks associated with genome editing techniques involving dsDNA breaks in E. coli and likely other bacteria and emphasize the importance of sequencing the genomes of edited cells to ensure the absence of unintended mutations.

Self-reported Measures of Function Compared to Lower Limb Motor Performance in People With and Without Imaging Evidence of Unilateral Lumbar Nerve Root Compression: A Cross-sectional Study.

OBJECTIVE: The primary objective of the present study was to determine if imaging findings of unilateral lumbar nerve root compression (ULNRC) impact performance on a coordinated motor performance task and to determine if there were correlations between motor performance and self-reported clinical measures. METHODS: People with back pain (N = 45) were stratified into 3 groups based on combinations of: lumbar imaging; and clinical presentation for ULNRC. Group 1 included people with imaging of lumbar nerve root compression, who presented with neurological deficit. Group 2 people demonstrated imaging evidence of nerve compression, without motor, sensory or reflex change. Group 3 participants possessed only degenerative changes on lumbar imaging films, and were neurologically intact. Performance measures included behavioral and kinematic variables from an established lower limb Fitts' Task requiring movements to targets of different difficulties. Self-reported measures of disability, function and pain were collected. Analysis of variance for between and within group variables were conducted, and Pearson correlation compared performance with self-reported measures. RESULTS: All groups yielded main effects for movement time with increasing task difficulty as predicted by Fitts' Law. A main effect revealed Group 1 participants performed less accurately than Group 3 participants. Positive correlations were predominantly found between self-report measures and motor performance for Group 2 and Group 3. CONCLUSION: Imaging, and self-reported measures alone did not predict function, however, Fitts' task performance accuracy effectively differentiated groups.

Ultrasonographic Fetal Nuchal Translucency Measurements and Cytogenetic Outcomes.

Importance: Ultrasonographic measurement of fetal nuchal translucency is used in prenatal screening for trisomies 21 and 18 and other conditions. A cutoff of 3.5 mm or greater is commonly used to offer follow-up investigations, such as prenatal cell-free DNA (cfDNA) screening or cytogenetic testing. Recent studies showed a possible association with chromosomal anomalies for levels less than 3.5 mm, but extant evidence has limitations. Objective: To evaluate the association between different nuchal translucency measurements and cytogenetic outcomes on a population level. Design, Setting, and Participants: This population-based retrospective cohort study used data from the Better Outcomes Registry & Network, the perinatal registry for Ontario, Canada. All singleton pregnancies with an estimated date of delivery from September 1, 2016, to March 31, 2021, were included. Data were analyzed from March 17 to August 14, 2023. Exposures: Nuchal translucency measurements were identified through multiple-marker screening results. Main Outcomes and Measures: Chromosomal anomalies were identified through all Ontario laboratory-generated prenatal and postnatal cytogenetic tests. Cytogenetic testing results, supplemented with information from cfDNA screening and clinical examination at birth, were used to identify pregnancies without chromosomal anomalies. Multivariable modified Poisson regression with robust variance estimation and adjustment for gestational age was used to compare cytogenetic outcomes for pregnancies with varying nuchal translucency measurement categories and a reference group with nuchal translucency less than 2.0 mm. Results: Of 414 268 pregnancies included in the study (mean [SD] maternal age at estimated delivery date, 31.5 [4.7] years), 359 807 (86.9%) had a nuchal translucency less than 2.0 mm; the prevalence of chromosomal anomalies in this group was 0.5%. An increased risk of chromosomal anomalies was associated with increasing nuchal translucency measurements, with an adjusted risk ratio (ARR) of 20.33 (95% CI, 17.58-23.52) and adjusted risk difference (ARD) of 9.94% (95% CI, 8.49%-11.39%) for pregnancies with measurements of 3.0 to less than 3.5 mm. The ARR was 4.97 (95% CI, 3.45-7.17) and the ARD was 1.40% (95% CI, 0.77%-2.04%) when restricted to chromosomal anomalies beyond the commonly screened aneuploidies (excluding trisomies 21, 18, and 13 and sex chromosome aneuploidies). Conclusions and Relevance: In this cohort study of 414 268 singleton pregnancies, those with nuchal translucency measurements less than 2.0 mm were at the lowest risk of chromosomal anomalies. Risk increased with increasing measurements, including measurements less than 3.5 mm and anomalies not routinely screened by many prenatal genetic screening programs.

Extracellular Poly(hydroxybutyrate) Bioplastic Production Using Surface Display Techniques.

Poly(hydroxybutyrate) is a biocompatible, biodegradable polyester synthesized naturally in a variety of microbial species. A greener alternative to petroleum-based plastics and sought after for biomedical applications, poly(hydroxybutyrate) has failed to break through as a leading material in the plastic industry due to its high cost of production. Specifically, the extraction of this material from within bacterial cells requires lysis of cells, which takes time, uses harsh chemicals, and starts the process again with growing new living cells. Recently, surface display of enzymes on bacterial membranes has become an emerging technique for extracellular biocatalysis. In this work, a fusion protein lpp-ompA-phaC was expressed in Escherichia coli to display the enzyme poly(hydroxyalkanoate) synthase on the cell surface. The resulting poly(hydroxybutyrate) product was chemically characterized by nuclear magnetic resonance and infrared spectroscopy. Finally, the extracellular synthesis of the bioplastic granules was demonstrated qualitatively via microscopy and quantitatively by flow cytometry. The results of this work are the first demonstration of extracellular synthesis of poly(hydroxybutyrate), showing promise for continuous and scalable synthesis of materials using surface display.

Electrocatalytic Asymmetric Nozaki-Hiyama-Kishi Decarboxylative Coupling: Scope, Applications, and Mechanism.

The first general enantioselective alkyl-Nozaki-Hiyama-Kishi (NHK) coupling reactions are disclosed herein by employing a Cr-electrocatalytic decarboxylative approach. Using easily accessible aliphatic carboxylic acids (via redox-active esters) as alkyl nucleophile synthons, in combination with aldehydes and enabling additives, chiral secondary alcohols are produced in a good yield with high enantioselectivity under mild reductive electrolysis. This reaction, which cannot be mimicked using stoichiometric metal or organic reductants, tolerates a broad range of functional groups and is successfully applied to dramatically simplify the synthesis of multiple medicinally relevant structures and natural products. Mechanistic studies revealed that this asymmetric alkyl e-NHK reaction was enabled by using catalytic tetrakis(dimethylamino)ethylene, which acts as a key reductive mediator to mediate the electroreduction of the CrIII/chiral ligand complex.

Synonymous edits in the Escherichia coli genome have substantial and condition-dependent effects on fitness.

CRISPR-Cas-based genome editing is widely used in bacteria at scales ranging from construction of individual mutants to massively parallel libraries. This procedure relies on guide RNA-directed cleavage of the genome followed by repair with a template that introduces a desired mutation along with synonymous "immunizing" mutations to prevent re-cleavage of the genome after editing. Because the immunizing mutations do not change the protein sequence, they are often assumed to be neutral. However, synonymous mutations can change mRNA structures in ways that alter levels of the encoded proteins. We have tested the assumption that immunizing mutations are neutral by constructing a library of over 50,000 edits that consist of only synonymous mutations in Escherichia coli. Thousands of edits had substantial effects on fitness during growth of E. coli on acetate, a poor carbon source that is toxic at high concentrations. The percentage of high-impact edits varied considerably between genes and at different positions within genes. We reconstructed clones with high-impact edits and found that 69% indeed had significant effects on growth in acetate. Interestingly, fewer edits affected fitness during growth in glucose, a preferred carbon source, suggesting that changes in protein expression caused by synonymous mutations may be most important when an organism encounters challenging conditions. Finally, we showed that synonymous edits can have widespread effects; a synonymous edit at the 5' end of ptsI altered expression of hundreds of genes. Our results suggest that the synonymous immunizing edits introduced during CRISPR-Cas-based genome editing should not be assumed to be innocuous.

Research Gaps in Pediatric Heart Failure: Defining the Gaps and Then Closing Them Over the Next Decade.

Given the numerous opportunities and the wide knowledge gaps in pediatric heart failure, an international group of pediatric heart failure experts with diverse backgrounds were invited and tasked with identifying research gaps in each pediatric heart failure domain that scientists and funding agencies need to focus on over the next decade.

Toddler milk: a scoping review of research on consumption, perceptions, and marketing practices.

Toddler milk is an ultra-processed beverage consisting primarily of powdered milk, caloric sweeteners, and vegetable oil. Pediatric health authorities do not support the use of toddler milk, and emerging evidence suggests that toddler-milk marketing practices may mislead consumers. However, studies have not synthesized the extent of toddler-milk marketing practices or how these practices affect parents' decisions about whether to serve toddler milk. We aimed to summarize the literature about toddler milk to identify what is known about: (1) parents' toddler-milk purchasing and feeding behaviors, (2) toddler-milk marketing, and (3) how marketing practices influence parents' beliefs and perceptions about toddler milk. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), we systematically searched 8 databases (PubMed, APA PsycINFO, Scopus, Cochrane Central, Embase, CINAHL, Communication & Mass Media Complete, and Business Source Premier). We identified 45 articles about toddler milk. Studies were conducted in 25 countries across 6 continents. Five types of findings emerged: (1) consumption and feeding behaviors, (2) demographic correlates of toddler-milk purchasing and consumption, (3) misperceptions and beliefs, (4) increased sales, and (5) increased marketing and responses to marketing. The included articles suggested that toddler-milk sales are growing rapidly worldwide. Findings also revealed that toddler-milk packages (eg, labels, branding) resemble infant formula packages and that toddler-milk marketing practices may indirectly advertise infant formula. Purchasing, serving, and consumption of toddler milk were higher in Black and Hispanic populations than in non-Hispanic White populations, and parents with higher educational attainment and income were more likely to offer toddler milk to their children. Findings suggest a need for policies to prevent cross-marketing of toddler milk and infant formula, reduce provision of toddler milk to infants and toddlers, and prevent caregivers from being misled about toddler-milk healthfulness.

Changes in estimated glomerular filtration rate over the first year following repeat heart transplant in children and young adults.

BACKGROUND: Renal function is reduced in patients undergoing heart transplant due to hemodynamic compromise, cardiorenal syndrome, and nephrotoxin exposure. No current studies evaluate renal function in retransplants. METHODS: We reviewed all heart transplants at our center from 1995 to 2021 and matched first-time heart transplants with retransplants, based on age at transplant, sex, and race. Estimated glomerular filtration rate (eGFR) was derived from CKiD-U25 calculator using creatinine and measured prior to transplant, 1-week post-transplant, 1-3, 6, and 12 months post-transplant, and recent follow-up. Changes in eGFR were measured within and between patients using a piecewise linear mixed effect model with matching. Exploratory univariate analysis was performed to evaluate pre-transplant risk factors for decreased eGFR. RESULTS: The unmatched cohort included 393 heart transplant recipients, with 47 being retransplants. Thirty-eight patients in both groups with at least 1 year of follow-up underwent matching. Both retransplants and first-time transplants had an initial decline in eGFR. eGFR rebounded to baseline or above baseline at 1-3 months post-transplant, but eGFR in retransplants remained significantly lower. At 1-year post-transplant, the average eGFR was 67.8 ± 4.3 mL/min/1.73 m2 versus 104.7 ± 4.3 mL/min/1.73 m2 (p < .001) in the retransplants and first-time transplants group, respectively. CONCLUSION: This study provides data on anticipated renal trajectory following retransplantation.

Phenyl Acrylate-Based Cross-Linked Anion Exchange Membranes for Non-aqueous Redox Flow Batteries.

Redox flow batteries (RFBs) are of recent interest to store harvested renewable energy for improving grid reliability and utilization. In this study, we synthesized and characterized a series of phenyl acrylate-based UV-cross-linked anion exchange membranes (AEMs) and explored the performance of these AEMs in a model non-aqueous RFB under model conditions. Infrared spectroscopy was utilized to confirm the incorporation of ion carriers in the phenyl acrylate backbone. The electrochemical performance was compared with the commercial Fumasep membrane Fuma-375 based on high stability in non-aqueous solvents, high permeability to the charge-carrying ion, low resistance, low crossover of the redox-active molecules, and low cost. Our results show 55% total capacity retention through 1000 charge/discharge cycles because of low crossover as compared to the Fumasep commercial membrane which retained only 28% capacity. This result is promising in understanding and developing next-generation AEMs for non-aqueous RFBs and other electrochemical systems utilizing organic solvents.

Advances in Bioelectrode Design for Developing Electrochemical Biosensors.

The critical performance factors such as selectivity, sensitivity, operational and storage stability, and response time of electrochemical biosensors are governed mainly by the function of their key component, the bioelectrode. Suitable design and fabrication strategies of the bioelectrode interface are essential for realizing the requisite performance of the biosensors for their practical utility. A multifaceted attempt to achieve this goal is visible from the vast literature exploring effective strategies for preparing, immobilizing, and stabilizing biorecognition elements on the electrode surface and efficient transduction of biochemical signals into electrical ones (i.e., current, voltage, and impedance) through the bioelectrode interface with the aid of advanced materials and techniques. The commercial success of biosensors in modern society is also increasingly influenced by their size (and hence portability), multiplexing capability, and coupling in the interface of the wireless communication technology, which facilitates quick data transfer and linked decision-making processes in real-time in different areas such as healthcare, agriculture, food, and environmental applications. Therefore, fabrication of the bioelectrode involves careful selection and control of several parameters, including biorecognition elements, electrode materials, shape and size of the electrode, detection principles, and various fabrication strategies, including microscale and printing technologies. This review discusses recent trends in bioelectrode designs and fabrications for developing electrochemical biosensors. The discussions have been delineated into the types of biorecognition elements and their immobilization strategies, signal transduction approaches, commonly used advanced materials for electrode fabrication and techniques for fabricating the bioelectrodes, and device integration with modern electronic communication technology for developing electrochemical biosensors of commercial interest.

Generation and influence of eccentric ideas on social networks.

Studying extreme ideas in routine choices and discussions is of utmost importance to understand the increasing polarization in society. In this study, we focus on understanding the generation and influence of extreme ideas in routine conversations which we label "eccentric" ideas. The eccentricity of any idea is defined as the deviation of that idea from the norm of the social neighborhood. We collected and analyzed data from two sources of different nature: public social media and online experiments in a controlled environment. We compared the popularity of ideas against their eccentricity to understand individuals' fascination towards eccentricity. We found that more eccentric ideas have a higher probability of getting a greater number of "likes". Additionally, we demonstrate that the social neighborhood of an individual conceals eccentricity changes in one's own opinions and facilitates generation of eccentric ideas at a collective level.

A thematic content analysis of 2010-2015 state tobacco control legislation in the United States: Bill rationales and priority populations.

Objective: Tobacco use causes numerous types of cancers, heart diseases, and chronic illnesses, and is responsible for nearly 1 in every 5 deaths in the United States (U.S.) annually. This study assessed whether tobacco control laws introduced in state legislatures between 2010 and 2015 provided a rationale for the proposed bill and/or specified priority population groups, and we then examined emerging themes in the text that did so. Methods: Using LexisNexis® State Net®, we identified tobacco control bills introduced in all states and coded their bill rationales and population category. We then conducted qualitative thematic analysis on a sample of bills with rationales or specified populations. Results: Of the 2815 tobacco control bills introduced in state legislatures in the analysis period, 422 (15.0%) included a bill rationale, and 1309 (46.5%) specified at least one priority population. Four overarching themes emerged: 1) Addressing tobacco-related health harms and financial costs incurred to society; 2) Protecting the public from tobacco-related harms as a government responsibility; 3) Providing services to priority populations; 4) Exempting or preempting some population groups and localities. Conclusions: Rationalizing tobacco control legislation by focusing on both health and cost implications was a key feature of tobacco policy bill text we analyzed; given the history of this approach, it is likely to remain so in the future. Our study may serve as a benchmark for tracking current and future tobacco control legislation to examine whether there is a growth in prioritizing populations experiencing unjust burdens of tobacco use and related disease.