About the Authors: Stephanie N. Langel * E-mail: stephanie.langel@duke.edu (SNL); sallie.permar@duke.edu (SRR) Affiliations Duke Human Vaccine Institute, Duke University Medical Center, Durham, North ...Carolina, United States of America, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America ORCID logo http://orcid.org/0000-0002-0467-7874 Claire E. Otero Affiliations Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America ORCID logo http://orcid.org/0000-0001-7127-2327 David R. Martinez Affiliation: Department of Epidemiology, University of North Carolina at Chapel Hill School of Public Health, Chapel Hill, North Carolina, United States of America Sallie R. Permar * E-mail: stephanie.langel@duke.edu (SNL); sallie.permar@duke.edu (SRR) Affiliations Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America ORCID logo http://orcid.org/0000-0003-1438-4554 Introduction Maternal antibodies (MatAbs) passively transferred across the placenta and into breast milk are critical for protection against infectious disease and immune development during the first year of life 1. Fab, antigen-binding fragment; Fc, crystallizable fragment; FcαR, Fc alpha receptor; FcRn, Fc receptor neonatal; FcγR, Fc gamma receptor; IgA, immunoglobulin A; IgG, immunoglobulin G; J-chain, joining chain; pIgR, polymeric immunoglobulin receptor. https://doi.org/10.1371/journal.ppat.1008303.g001 The IgG Fc domain mediates considerable heterogeneity of its effector functions depending on the subclass and glycan profile. IgA, immunoglobulin A; IgG, immunoglobulin G; sIgA2, secretory IgA. https://doi.org/10.1371/journal.ppat.1008303.g002 Do IgA Fc region characteristics influence IgA passive transfer or effector function in breast milk? Studies are needed to define the mechanisms of Fc-mediated IgA effector functions in breast milk, including their interactions with the developing infant microbiome and protection against intestinal viral infections.
A new method based on headspace single-drop microextraction in combination with UV–vis micro-spectrophotometry has been developed for the ultrasensitive determination of banned sulphite preservatives ...(E220–228) in fruits and vegetables. Sample acidification was used for SO
2
generation, which is collected onto a 5,5′-dithiobis-(2-nitrobenzoic acid) microdrop for spectrophotometric measurement. A careful study of this reaction was necessary, including conditions for SO
2
generation from different sulphating salts, drop pH, 5,5′-dithiobis-(2-nitrobenzoic acid) concentration and potential interference effects. Variables influencing mass transfer (stirring, sample volume and addition of salt) and microextraction time were also studied. A simple sulphite extraction was carried out, and problems caused by oxidation during the extraction process were addressed. A high enrichment factor (380) allows the determination of low levels of free SO
2
in fruits and vegetables (limit of detection 0.06 μg g
−1
, limit of quantification 0.2 μg g
−1
) with an adequate precision (repeatability, relative standard deviation 5 %). In addition, the sulphiting process was studied through the monitoring of residual SO
2
in a vegetal sample, thus showing the importance of a sensitive tool for SO
2
detection at low levels.
In situ generation of SO
2
from sulphite preservatives and detection by micro-spectrophotometry
Flexizymes, highly flexible tRNA aminoacylation ribozymes, have enabled charging of virtually any amino acid (including non-proteogenic ones) onto tRNA molecules. Coupling to a custom-made in vitro ...translation system, namely the flexible in vitro translation (FIT) system, has unveiled the remarkable tolerance of the ribosome toward molecules, remote from what nature has selected to carry out its elaborate functions. Among the very diverse molecules and chemistries that have been ribosomally incorporated, a plethora of entities capable of mediating intramolecular cyclization have revolutionized the design and discovery of macrocyclic peptides. These macrocyclization reactions (which can be spontaneous, chemical, or enzymatic) have all served as tools for the discovery of peptides with natural-like structures and properties. Coupling of the FIT system and mRNA display techniques, known as the random non-standard peptide integrated discovery (RaPID) system, has in turn allowed for the simultaneous screening of trillions of macrocyclic peptides against challenging biological targets. The macrocyclization methodologies are chosen depending on the structural and functional characteristics of the desired molecule. Thus, they can emanate from the peptide's N-terminus or its side chains, attributing flexibility or rigidity, or even result in the installation of fluorescent probes.
Ant colony optimization (ACO) algorithms have been successfully applied to discover a list of classification rules. In general, these algorithms follow a sequential covering strategy, where a single ...rule is discovered at each iteration of the algorithm in order to build a list of rules. The sequential covering strategy has the drawback of not coping with the problem of rule interaction, i.e., the outcome of a rule affects the rules that can be discovered subsequently since the search space is modified due to the removal of examples covered by previous rules. This paper proposes a new sequential covering strategy for ACO classification algorithms to mitigate the problem of rule interaction, where the order of the rules is implicitly encoded as pheromone values and the search is guided by the quality of a candidate list of rules. Our experiments using 18 publicly available data sets show that the predictive accuracy obtained by a new ACO classification algorithm implementing the proposed sequential covering strategy is statistically significantly higher than the predictive accuracy of state-of-the-art rule induction classification algorithms.
Transversus abdominis plane (TAP) block is a regional anesthetic technique used to desensitize the abdominal wall in several species. This study aimed to describe the anatomical characteristics of ...the abdominal wall and to identify a feasible approach for an US-guided TAP injection that would result in adequate staining of the relevant nerves in the abdominal wall in pig cadavers. Fresh cadavers from five Landrace pigs (age, 12 weeks; body weight, 35.5 ± 1.6 kg) were used. One pig (n = 1) was anatomically dissected, and four pigs (n = 4; i.e., 8 hemiabdomens) were used for TAP injections and evaluation of dye spread. The volume of 0.3 mL/kg/injection point of methylene blue was injected bilaterally. In the caudal retrocostal approach, the injection was performed ventral to the most caudal part of the costal arch. In the lateral approach, the injection was performed between the last rib and iliac crest. A needle was inserted in plane for the caudal retrocostal and the lateral approach caudocranially and craniocaudally, respectively. Successful staining was defined as presence of dye on the nerve for a length of >1 cm in its entire circumference. The TAP was found between different muscle layers in the described anatomical regions. In the caudal retrocostal approach the TAP was found between the external abdominal oblique and transversus abdominis muscle bellies. In the lateral approach the TAP was found between the internal abdominal oblique and transversus abdominis muscles. The approach combining lateral and caudal retrocostal injections at the studied volume stained a median of 5 (3-6) target nerves from the fourth-last thoracic nerve to L2 (six nerves). Combined caudal retrocostal and lateral TAP injections of 0.3 mL/kg/injection point, resulted in staining of target nerve branches which supply the periumbilical and caudal abdominal wall in pig cadavers.
Esta investigación presenta cómo el comportamiento de compra de los millennials en los últimos años ha incorporado elementos de valoración adicionales a los tradicionales para la toma de decisiones, ...particularmente en su orientación al consumo de bienes y servicios turísticos. El objetivo de esta investigación es identificar las estrategias de marketing turístico orientadas a los millennials que incluyen prácticas sustentables para generar un vínculo comunicativo y anclaje con el consumidor. Es una investigación documental desarrollada a través de la revisión de literatura especializada, y mediante el análisis de artículos científicos, journals de marketing, comportamiento del consumidor y turismo. Además, se realizó un análisis de cada documento para inferir conclusiones que expliquen este fenómeno. Los principales hallazgos de esta investigación muestran una evidente orientación de los millennials a evaluar a las empresas turísticas a partir de su reputación digital, de las prácticas sustentables que manejan en su comunicación interna y externa, de los comentarios que sus iguales (otros millennials) manifiestan en las redes sociales y sitios web turísticos.
The current COVID-19 pandemic has led the world to an unprecedented global shortage of ventilators, and its sharing has been proposed as an alternative to meet the surge. This study outlines the ...performance of a preformed novel interface called ’ACRA’, designed to split ventilator outflow into two breathing systems. The ’ACRA’ interface was built using medical use approved components. It consists of four unidirectional valves, two adjustable flow-restrictor valves placed on the inspiratory limbs of each unit, and one adjustable PEEP valve placed on the expiratory limb of the unit that would require a greater PEEP. The interface was interposed between a ventilator and two lung units (phase I), two breathing simulators (phase II) and two live pigs with heterogeneous lung conditions (phase III). The interface and ventilator adjustments tested the ability to regulate individual pressures and the resulting tidal volumes. Data were analyzed using Friedman and Wilcoxon tests test (p < 0.05). Ventilator outflow splitting, independent pressure adjustments and individual tidal volume monitoring were feasible in all phases. In all experimental measurements, dual ventilation allowed for individual and tight adjustments of the pressure, and thus volume delivered to each paired lung unit without affecting the other unit’s ventilation—all the modifications performed on the ventilator equally affected both paired lung units. Although only suggested during a dire crisis, this experiment supports dual ventilation as an alternative worth to be considered.
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