Time Course of Mechanical Ventilation Driving Pressure Levels in Pediatric Acute Respiratory Distress Syndrome: Outcomes in a Prospective, Multicenter Cohort Study From Colombia, 2018-2022.

OBJECTIVES: High driving pressure (DP, ratio of tidal volume (Vt) over respiratory system compliance) is a risk for poor outcomes in patients with pediatric acute respiratory distress syndrome (PARDS). We therefore assessed the time course in level of DP (i.e., 24, 48, and 72 hr) after starting mechanical ventilation (MV), and its association with 28-day mortality. DESIGN: Multicenter, prospective study conducted between February 2018 and December 2022. SETTING: Twelve tertiary care PICUs in Colombia. PATIENTS: One hundred eighty-four intubated children with moderate to severe PARDS. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The median (interquartile range [IQR]) age of the PARDS cohort was 11 (IQR 3-24) months. A total of 129 of 184 patients (70.2%) had a pulmonary etiology leading to PARDS, and 31 of 184 patients (16.8%) died. In the first 24 hours after admission, the plateau pressure in the nonsurvivor group, compared with the survivor group, differed (28.24 [IQR 24.14-32.11] vs. 23.18 [IQR 20.72-27.13] cm H2O, p < 0.01). Of note, children with a Vt less than 8 mL/kg of ideal body weight had lower adjusted odds ratio (aOR [95% CI]) of 28-day mortality (aOR 0.69, [95% CI, 0.55-0.87]; p = 0.02). However, we failed to identify an association between DP level and the oxygenation index (aOR 0.58; 95% CI, 0.21-1.58) at each of time point. In a diagnostic exploratory analysis, we found that DP greater than 15 cm H2O at 72 hours was an explanatory variable for mortality, with area under the receiver operating characteristic curve of 0.83 (95% CI, 0.74-0.89); there was also increased hazard for death with hazard ratio 2.5 (95% CI, 1.07-5.92). DP greater than 15 cm H2O at 72 hours was also associated with longer duration of MV (10 [IQR 7-14] vs. 7 [IQR 5-10] d; p = 0.02). CONCLUSIONS: In children with moderate to severe PARDS, a DP greater than 15 cm H2O at 72 hours after the initiation of MV is associated with greater odds of 28-day mortality and a longer duration of MV. DP should be considered a variable worth monitoring during protective ventilation for PARDS.

[Characterization of asthma phenotypes in children of the tropics]. / Caracterización de fenotipos de asma en niños del trópico.

OBJECTIVE: Determine the main asthma phenotypes in a population of asthmatic children in Cartagena, Colombia. METHODS: 107 children (7 to 17 years old) with a previous diagnosis of asthma were recruited. Biomarkers of T2 inflammation were evaluated by measuring FeNO, eosinophil count in peripheral blood by hemocytometry, and determination of specific IgE to mite allergens by ELISA. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405). RESULTS: The average age of patients was 10,9 years. 19,6% of the children did not show elevation of any of the T2 inflammation biomarkers evaluated (FeNO<20ppb, eos<300/ul, negative specific IgE), so they were considered patients with non-allergic asthma (non-T2). 71,9% of all patients were sensitized to at least one allergen, this phenotype was considered allergic asthma. 30,8% of the patients presented the three elevated biomarkers (FeNO>20ppb + eos >300/ul + positive specific IgE), this phenotype was classified as high T2 allergic asthma. A moderate correlation (Spearman rho=0,44, p<0,0001) was found between FeNO values and eosinophil counts. CONCLUSION: In this study, the following phenotypes were found: allergic asthma, high T2 asthma, and non-allergic asthma. Most patients presented a type 2 inflammatory phenotype with allergic sensitization. In addition to the measurement of specific IgE, the use of FeNO and eosinophil count in peripheral blood help to accurately determine those patients with high T2 asthma phenotypes.

OBJETIVO: Determinar los fenotipos principales de asma en una población de niños asmáticos en Cartagena, Colombia. MÉTODOS: Se reclutaron 107 niños (entre 7 y 17 años), con diagnóstico previo de asma. Se evaluaron biomarcadores de inflamación T2 mediante la medición de FeNO, conteo de eosinófilos en sangre periférica mediante hemocitometría, y la determinación de IgE específica a alergenos de ácaros mediante ELISA. El estudio fue aprobado por el Comité de Ëtica de la Universidad de Cartagena (SGR, Grant BPIN2020000100405). RESULTADOS: La edad media de los pacientes fue de 10,9 años. El 19,6% de los niños no mostró elevación de ninguno de los biomarcadores de inflamación T2 evaluados (FeNO<20 ppb, eos<300/ul, IgE específica negativa), por lo que se consideraron como pacientes con asma no alérgica (no-T2). El 71,9% de todos los pacientes estaban sensibilizados al menos a un alergeno considerándose este fenotipo como asma alérgica. El 30,8% de los pacientes presentaron los tres biomarcadores elevados (FeNO>20 ppb + eos >300/ul + IgE específica positiva), clasificando este fenotipo como asma alérgica T2 alta. Se encontró una correlación moderada (Spearman rho=0,44, p<0,0001) entre los valores de FeNO y los conteos de eosinófilos. CONCLUSIÓN: En este estudio se encontraron los siguientes fenotipos de asma alérgica: asma T2 alta y asma no alérgica. La mayoría de los pacientes presentó un fenotipo inflamatorio tipo 2 con sensibilización alérgica. Además de la medición de la IgE específica, el uso del FeNO y los conteos de eosinófilos en sangre periférica ayudan a determinar con mayor exactitud a aquellos pacientes con fenotipos de asma T2 alto.

[Circulating populations of CD4+ CD25+ CD127- regulatory t lymphocytes in peripheral blood of allergic asthmatic children]. / Determinación de poblaciones circulantes en sangre periférica de linfocitos T, reguladores CD4+ CD25+ CD127-, en niños asmáticos alérgicos.

OBJECTIVE: To carry out a preliminary analysis on the Treg lymphocyte counts present in the peripheral blood of allergic asthmatic children from the city of Cartagena, Colombia, compared to healthy controls. METHODS: We compared cytometry counts of ten asthmatic patients (age 7-16 years) and seven healthy controls (6-12 years), recruited in the city of Cartagena. Peripheral blood samples were stained using Cytek's 14-color cFluor Immunoprofiling kit (Cytek® cFluor® Immunoprofiling Kit 14 Color RUO kit), and analyzed on a Northern Lights™ spectral cytometer (Cytek® Biosciences, Fremont, CA, USA), to read 50.000 events per sample. The data obtained were analyzed in SpectroFlo® and FlowJo. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405). RESULTS: The frequency of CD3+, CD4+, CD25+, CD127- Tregs was 11% of all CD4+ T cells, with a range of minimum 8,1% and maximum 17,7%. There was no significant difference in the proportion of Tregs between allergic asthmatic patients and healthy controls (P = 0,2). CONCLUSIONS: With this preliminary sample size, no significant differences were found in the Treg lymphocyte population between allergic asthmatic patients and healthy controls. The 14-color multiplexed panel is a useful tool not only to count CD3+ and CD4+ populations, but also to obtain the percentage of regulatory T cells using cell surface markers.

OBJETIVO: Realizar un análisis preliminar sobre los conteos de linfocitos Tregs presentes en sangre periférica de niños asmáticos alérgicos de la ciudad de Cartagena, comparado con controles sanos. MÉTODOS: Se compararon los conteos de citometría de diez pacientes asmáticos (entre 7 y16 años) y siete controles sanos (entre 6 y12 años), reclutados en la ciudad de Cartagena. La muestra de sangre periférica fue teñida empleando el kit de inmunofenotipo multiplexado de 14 colores de Cytek (Cytek® cFluor® Immunoprofiling Kit 14 Color), y analizada en un citómetro espectral Northern Lights™ (Cytek® Biosciences, Fremont, CA, USA), a lectura de 50.000 eventos por muestra. Los datos obtenidos fueron analizados en SpectroFlo® y FlowJo. El estudio fue aprobado por el Comité de Ética de la Universidad de Cartagena. RESULTADOS: El panel de tinción funcionó apropiadamente y dentro de los parámetros apropiados. Se obtuvo un promedio de células Tregs CD3+, CD4+, CD25+ y CD127- del 11% de todos los CD4+ en las muestras estudiadas, con un rango de mínimo de 8,1% y un máximo de 17,7%. No hubo diferencias significativas en la proporción de linfocitos Tregs entre los pacientes asmáticos alérgicos y los controles sanos (P = 0.2). CONCLUSIONES: Con este tamaño de muestra preliminar, no se encontraron diferencias significativas en la población de linfocitos Tregs entre los pacientes asmáticos alérgicos y los controles sanos. El panel multiplexado de 14 colores es una herramienta útil no solo para derivar las poblaciones CD3+ y CD4+, sino también para obtener el porcentaje de células T reguladoras empleando marcadores de superficie celular.

Ovalbumin interaction with polystyrene and polyethylene terephthalate microplastics alters its structural properties.

Contaminating microplastics can interact with food proteins in the food matrix and during digestion. This study investigated adsorption of chicken egg protein ovalbumin to polystyrene (PS, 110 and 260 µm) and polyethylene terephthalate (PET, 140 µm) MPs in acidic and neutral conditions and alterations in ovalbumin structure. Ovalbumin adsorption affinity depended on MPs size (smaller > larger), type (PS > PET) and pH (pH 3 > pH 7). In bulk solution, MPs does not change ovalbumin secondary structure significantly, but induces loosening (at pH 3) and tightening (at pH 7) of tertiary structure. Formed soft corona exclusively consists of full length non-native ovalbumin, while in hard corona also shorter ovalbumin fragments were found. At pH 7 soft corona ovalbumin has rearranged but still preserved level of ordered secondary structure, resulting in preserved thermostability and proteolytic stability, but decreased ability to form fibrils upon heating. Secondary structure changes in soft corona resemble changes in native ovalbumin induced by heat treatment (80 °C). Ovalbumin is abundantly present in corona around microplastics also in the presence of other egg white proteins. These results imply that microplastics contaminating food may bind and change structure and functional properties of the main egg white protein.

Borderline Personality Disorder and Intimate Partner Violence: A Systematic Review / Trastorno Límite de Personalidad y Violencia en la Pareja: una Revisión Sistemática

Borderline personality (BPD) features and intimate partner violence (IPV) have been seen associated, focusing the research specially into perpetrators. The achievement of this systematic review is to analyze this relation in both victims and perpetrators, using 17 scientific articles published between 2017 and 2021 from different data bases. Most studies were focused on perpetrators, in which both men and women were equally represented as perpetrators. Instead, studies about victims were focused on women. Throughout this review, different factors observed in people with BPD traits who are victims or perpetrators of IPV are mentioned, finding particularities in each profile. These findings allow increase knowledge about the relationship between BPD and IPV, promoting a greater understanding that impacts positively on clinical intervention in this population.(AU)

Los rasgos límites de personalidad (TLP) se han visto asociados a violencia en la pareja, con investigaciones centradas especialmente en quienes la ejercen. El objetivo de esta revisión sistemática es analizar esta relación tanto en víctimas como en perpetradores, utilizando 17 artículos científicos publicados entre 2017 y 2021 en distintas bases de datos. Los estudios analizados se centraron mayoritariamente en perpetradores, encontrándose tanto hombres como mujeres igualmente representadas. En cambio, los estudios sobre víctimas atendían por lo general a mujeres. A lo largo de esta revisión, se mencionan distintos factores observados en personas que presentan rasgos TLP y ejercen o son víctimas de violencia de pareja, encontrando particularidades en cada perfil. Este trabajo permite incrementar el conocimiento sobre la relación existente entre TLP y violencia de pareja, fomentando una mayor comprensión que repercuta positivamente en la intervención clínica de esta población.(AU)

Gold Nanoparticle-Decorated Catalytic Micromotor-Based Aptassay for Rapid Electrochemical Label-Free Amyloid-ß42 Oligomer Determination in Clinical Samples from Alzheimer's Patients.

Micromotor (MM) technology offers a valuable and smart on-the-move biosensing microscale approach in clinical settings where sample availability is scarce in the case of Alzheimer's disease (AD). Soluble amyloid-ß protein oligomers (AßO) (mainly AßO42) that circulate in biological fluids have been recognized as a molecular biomarker and therapeutic target of AD due to their high toxicity, and they are correlated much more strongly with AD compared to the insoluble Aß monomers. A graphene oxide (GO)-gold nanoparticles (AuNPs)/nickel (Ni)/platinum nanoparticles (PtNPs) micromotors (MMGO-AuNPs)-based electrochemical label-free aptassay is proposed for sensitive, accurate, and rapid determination of AßO42 in complex clinical samples such as brain tissue, cerebrospinal fluid (CSF), and plasma from AD patients. An approach that implies the in situ formation of AuNPs on the GO external layer of tubular MM in only one step during MM electrosynthesis was performed (MMGO-AuNPs). The AßO42 specific thiolated-aptamer (AptAßO42) was immobilized in the MMGO-AuNPs via Au-S interaction, allowing for the selective recognition of the AßO42 (MMGO-AuNPs-AptAßO42-AßO42). AuNPs were smartly used not only to covalently bind a specific thiolated-aptamer for the design of a label-free electrochemical aptassay but also to improve the final MM propulsion performance due to their catalytic activity (approximately 2.0× speed). This on-the-move bioplatform provided a fast (5 min), selective, precise (RSD < 8%), and accurate quantification of AßO42 (recoveries 94-102%) with excellent sensitivity (LOD = 0.10 pg mL-1) and wide linear range (0.5-500 pg mL-1) in ultralow volumes of the clinical sample of AD patients (5 µL), without any dilution. Remarkably, our MM-based bioplatform demonstrated the competitiveness for the determination of AßO42 in the target samples against the dot blot analysis, which requires more than 14 h to provide qualitative results only. It is also important to highlight its applicability to the potential analysis of liquid biopsies as plasma and CSF samples, improving the reliability of the diagnosis given the heterogeneity and temporal complexity of neurodegenerative diseases. The excellent results obtained demonstrate the analytical potency of our approach as a future tool for clinical/POCT (Point-of-care testing) routine scenarios.

Implementation of a Bleeding Management Algorithm in Liver Transplantation: A Pilot Study.

Objectives: The aims of the study were to compare the consumption of blood products before and after the implementation of a bleeding management algorithm in patients undergoing liver transplantation and to determine the feasibility of a multicentre, randomized study. Background: Liver transplantation remains the only curative therapy for patients with end-stage liver disease, but it carries a high risk of surgical bleeding. Materials and Methods: Retrospective study of patients treated before (group 1) and after (group 2) implementation of a haemostatic algorithm guided by viscoelastic testing, including use of lyophilized coagulation factor concentrates (prothrombin complex and fibrinogen concentrates). Primary outcome was the number of units of blood products transfused in 24 h after surgery. Secondary outcomes included hospital stay, mortality, and cost. Results: Data from 30 consecutive patients was analysed; 14 in group 1 and 16 in group 2. Baseline data were similar between groups. Median total blood product consumption 24 h after surgery was 33 U (IQR: 11-57) in group 1 and 1.5 (0-23.5) in group 2 (p = 0.028). Significantly fewer units of red blood cells, fresh frozen plasma, and cryoprecipitate were transfused in group 2 versus group 1. There was no significant difference in complications, hospital stay, or in-hospital mortality between groups. The cost of haemostatic therapy was non-significantly lower in group 2 versus group 1 (7,400 vs. 15,500 USD; p = 0.454). Conclusion: The haemostatic management algorithm was associated with a significant reduction in blood product use during 24 h after liver transplantation. This study demonstrated the feasibility and provided a sample size calculation for a larger, randomized study.

Micromotor-based electrochemical immunoassays for reliable determination of amyloid-ß (1-42) in Alzheimer's diagnosed clinical samples.

Alzheimer's disease (AD), in addition to being the most common cause of dementia, is very difficult to diagnose, with the 42-amino acid form of Aß (Aß-42) being one of the main biomarkers used for this purpose. Despite the enormous efforts made in recent years, the technologies available to determine Aß-42 in human samples require sophisticated instrumentation, present high complexity, are sample and time-consuming, and are costly, highlighting the urgent need not only to develop new tools to overcome these limitations but to provide an early detection and treatment window for AD, which is a top-challenge. In recent years, micromotor (MM) technology has proven to add a new dimension to clinical biosensing, enabling ultrasensitive detections in short times and microscale environments. To this end, here an electrochemical immunoassay based on polypyrrole (PPy)/nickel (Ni)/platinum nanoparticles (PtNPs) MM is proposed in a pioneering manner for the determination of Aß-42 in left prefrontal cortex brain tissue, cerebrospinal fluid, and plasma samples from patients with AD. MM combines the high binding capacity of their immunorecognition external layer with self-propulsion through the catalytic generation of oxygen bubbles in the internal layer due to decomposition of hydrogen peroxide as fuel, allowing rapid bio-detection (15 min) of Aß-42 with excellent selectivity and sensitivity (LOD = 0.06 ng/mL). The application of this disruptive technology to the analysis of just 25 µL of the three types of clinical samples provides values concordant with the clinical values reported, thus confirming the potential of the MM approach to assist in the reliable, simple, fast, and affordable diagnosis of AD by determining Aß-42.

Micromotor-based dual aptassay for early cost-effective diagnosis of neonatal sepsis.

Given the long-life expectancy of the newborn, research aimed at improving sepsis diagnosis and management in this population has been recognized as cost-effective, which at early stages continues to be a tremendous challenge. Despite there is not an ideal-specific biomarker, the simultaneous detection of biomarkers with different behavior during an infection such as procalcitonin (PCT) as high specificity biomarker with one of the earliest biomarkers in sepsis as interleukin-6 (IL-6) increases diagnostic performance. This is not only due to their high positive predictive value but also, since it can also help the clinician to rule out infection and thus avoid the use of antibiotics, due to their high negative predictive value. To this end, we explore a cutting-edge micromotor (MM)-based OFF-ON dual aptassay for simultaneous determination of both biomarkers in 15 min using just 2 µL of sample from low-birth-weight neonates with gestational age less than 32 weeks and birthweight below 1000 g with clinical suspicion of late-onset sepsis. The approach reached the high sensitivities demanded in the clinical scenario (LODPCT = 0.003 ng/mL, LODIL6 = 0.15 pg/mL) with excellent correlation performance (r > 0.9990, p < 0.05) of the MM-based approach with the Hospital method for both biomarkers during the analysis of diagnosed samples and reliability (Er < 6% for PCT, and Er < 4% for IL-6). The proposed approach also encompasses distinctive technical attributes in a clinical scenario since its minimal sample volume requirements and expeditious results compatible with few easy-to-obtain drops of heel stick blood samples from newborns admitted to the neonatal intensive care unit. This would enable the monitoring of both sepsis biomarkers within the initial hours after the manifestation of symptoms in high-risk neonates as a valuable tool in facilitating prompt and well-informed decisions about the initiation of antibiotic therapy.These results revealed the asset behind micromotor technology for multiplexing analysis in diagnosing neonatal sepsis, opening new avenues in low sample volume-based diagnostics.

In situ and in vitro evaluation of two antiseptics for blood bank based on chlorhexidine gluconate/isopropyl alcohol and povidone-iodine.

BACKGROUND: Poor disinfection is the main cause of blood contamination, so its elimination is key to limiting the entry of bacteria into the collection system. With the advancement of antiseptic technology, antiseptics with sterile, disposable applicators are now available. AIM: To evaluate in situ two antiseptics (with and without applicators) for blood banks and to demonstrate in vitro antiseptic activity on bacterial biofilms of importance in transfusion medicine. METHODS: Antiseptic A (2% sterile solution of chlorhexidine gluconate/70% isopropyl alcohol provided with applicator) and bulk antiseptic B (10% povidone-iodine) were evaluated. The deferred blood donor arms were subjected to disinfection with antiseptics A and B and the contralateral arms were cultured to determine the baseline bacterial load (control). Antiseptic activity was assessed by ANOVA and logaritmic reduction values (LRV) and percentage reduction values (PRV) were calculated. Finally, the in vitro activity of antiseptic A was analyzed by confocal laser scanning microscopy (CLSM) on biofilm models. RESULTS: Prior to disinfection tests, commensal and clinically important bacteria were identified; antiseptic A showed post-disinfection bacterial growth rates of zero compared to controls (p < 0.0001). The frequency of bacterial growth with antiseptic B was 74%. A significant difference was identified between both antiseptics, where antiseptic A showed higher activity (p < 0.5468). LRV and PRV were 0.6-2.5/100% and 0.3-1.7/66.7-99.7% for antiseptics A and B, respectively. Through CLSM, disinfectant A (without applicator) showed lower in vitro antiseptic activity on the tested biofilms at the exposure times recommended by the manufacturer. CONCLUSIONS: Sterile solution of chlorhexidine gluconate/isopropyl alcohol with applicator showed advantages disinfection in deferred blood donors over povidone-iodine.

Rapid Environmental Contamination with Candida auris and Multidrug-Resistant Bacterial Pathogens Near Colonized Patients.

BACKGROUND: Environmental contamination is suspected to play an important role in Candida auris transmission. Understanding speed and risks of contamination after room disinfection could inform environmental cleaning recommendations. METHODS: We conducted a prospective multicenter study of environmental contamination associated with C. auris colonization at six ventilator-capable skilled nursing facilities and one acute-care hospital in Illinois and California. Known C. auris carriers were sampled at five body-sites followed by sampling of nearby room surfaces before disinfection and at 0, 4, 8, and 12-hours post-disinfection. Samples were cultured for C. auris and bacterial multidrug-resistant organisms (MDROs). Odds of surface contamination after disinfection were analyzed using multilevel generalized estimating equations. RESULTS: Among 41 known C. auris carriers, colonization was detected most frequently on palms/fingertips (76%) and nares (71%). C. auris contamination was detected on 32.2% (66/205) of room surfaces pre-disinfection and 20.5% (39/190) of room surfaces by 4-hours post-disinfection. A higher number of C. auris-colonized body sites was associated with higher odds of environmental contamination at every time point following disinfection, adjusting for facility of residence. In the rooms of 38 (93%) C. auris carriers co-colonized with a bacterial MDRO, 2%-24% of surfaces were additionally contaminated with the same MDRO by 4-hours post-disinfection. CONCLUSIONS: C. auris can contaminate the healthcare environment rapidly after disinfection, highlighting the challenges associated with environmental disinfection. Future research should investigate long-acting disinfectants, antimicrobial surfaces, and more effective patient skin antisepsis to reduce the environmental reservoir of C. auris and bacterial MDROs in healthcare settings.

Cell type dependent stability and virulence of a recombinant SARS-CoV-2, and engineering of a propagation deficient RNA replicon to analyze virus RNA synthesis.

Engineering of reverse genetics systems for newly emerged viruses allows viral genome manipulation, being an essential tool for the study of virus life cycle, virus-host interactions and pathogenesis, as well as for the development of effective antiviral strategies. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emergent human coronavirus that has caused the coronavirus disease (COVID-19) pandemic. The engineering of a full-length infectious cDNA clone and a fluorescent replicon of SARS-CoV-2 Wuhan-Hu-1, using a bacterial artificial chromosome, is reported. Viral growth and genetic stability in eleven cell lines were analyzed, showing that both VeroE6 cells overexpressing transmembrane serin protease 2 (TMPRSS2) and human lung derived cells resulted in the optimization of a cell system to preserve SARS-CoV-2 genetic stability. The recombinant SARS-CoV-2 virus and a point mutant expressing the D614G spike protein variant were virulent in a mouse model. The RNA replicon was propagation-defective, allowing its use in BSL-2 conditions to analyze viral RNA synthesis. The SARS-CoV-2 reverse genetics systems developed constitute a useful tool for studying the molecular biology of the virus, the development of genetically defined vaccines and to establish systems for antiviral compounds screening.

Extracellular Vesicles from Immune Cells: A Biomedical Perspective.

Research on the role of extracellular vesicles (sEV) in physiology has demonstrated their undoubted importance in processes such as the transportation of molecules with significance for cell metabolism, cell communication, and the regulation of mechanisms such as cell differentiation, inflammation, and immunity. Although the role of EVs in the immune response is actively investigated, there is little literature revising, in a comprehensive manner, the role of small EVs produced by immune cells. Here, we present a review of studies reporting the release of sEV by different types of leukocytes and the implications of such observations on cellular homeostasis. We also discuss the function of immune cell-derived sEV and their relationship with pathological states, highlighting their potential application in the biomedical field.

Life Cycle Assessment of Rare Earth Elements-Free Permanent Magnet Alternatives: Sintered Ferrite and Mn-Al-C.

Permanent magnets are fundamental constituents in key sectors such as energy and transport, but also robotics, automatization, medicine, etc. High-performance magnets are based on rare earth elements (RE), included in the European list of critical raw materials list. The volatility of their market increased the research over the past decade to develop RE-free magnets to fill the large performance/cost gap existing between ferrites and RE-based magnets. The improvement of hard ferrites and Mn-Al-C permanent magnets plays into this important technological role in the near future. The possible substitution advantage was widely discussed in the literature considering both magnetic properties and economic aspects. To evaluate further sustainability aspects, the present paper gives a life cycle assessment quantifying the environmental gain resulting from the production of RE-free magnets based on traditional hexaferrite and Mn-Al-C. The analysis quantified an advantage of both magnets that overcomes the 95% in all the considered impact categories (such as climate change, ozone depletion, human toxicity) compared to RE-based technologies. The benefit also includes the health and safety of working time aspects, proving possible reduction of worker risks by 3-12 times. The results represent the fundamentals for the development of green magnets that are able to significantly contribute to an effective sustainable transition.

Operando High-Energy-Resolution X-ray Spectroscopy of Evolving Cu Nanoparticle Electrocatalysts for CO2 Reduction.

Advances in electrocatalysis research rely heavily on building a thorough mechanistic understanding of catalyst active sites under realistic operating conditions. Only recently have techniques emerged that enable sensitive spectroscopic data collection to distinguish catalytically relevant surface sites from the underlying bulk material under applied potential in the presence of an electrolyte layer. Here, we demonstrate that operando high-energy-resolution fluorescence detected X-ray absorption spectroscopy (HERFD-XAS) is a powerful spectroscopic method which offers critical surface chemistry insights in CO2 electroreduction with sub-electronvolt energy resolution using hard X-rays. Combined with the high surface area-to-volume ratio of 5 nm copper nanoparticles, operando HERFD-XAS allows us to observe with clear evidence the breaking of chemical bonds between the ligands and the Cu surface as part of the ligand desorption process occurring under electrochemical potentials relevant for the CO2 reduction reaction (CO2RR). In addition, the dynamic evolution of oxidation state and coordination number throughout the operation of the nanocatalyst was continuously tracked. With these results in hand, undercoordinated metallic copper nanograins are proposed to be the real active sites in the CO2RR. This work emphasizes the importance of HERFD-XAS compared to routine XAS in catalyst characterization and mechanism exploration, especially in the complicated electrochemical CO2RR.

Propiedades psicométricas de la "Escala de motivación académica" adaptada para la educación profesional en enfermería / Psychometric properties of the "Academic motivation scale" adapted for the professional nursing education

Resumen Objetivo: El presente trabajo tuvo por objetivo realizar una adaptación de la Escala de Motivación Académica (EMA) para su uso en la educación profesional en enfermería (EMA-Enf) y evaluar sus propiedades psicométricas. Materiales y métodos: Se realizó una adaptación a una versión en español de la EMA para su uso en el contexto de la educación profesional en enfermería. Se desarrolló un cuestionario estructurado y se aplicó a 447 estudiantes de Licenciatura en Enfermería en Michoacán, México. Se realizó análisis factorial confirmatorio (AFC) para probar el ajuste de diferentes modelos derivados de la Teoría de la Autodeterminación (TAD). Se utilizó el software SPSS para la gestión de base de datos y software R, para la estimación de los modelos considerando la naturaleza ordinal de los ítems. Se evaluó la consistencia interna a través de los Coeficientes α y ω. Resultados: En el AFC se observó que el modelo de siete factores correlacionados propuesto en la TAD logra el mejor ajuste (χ2= 951.88 p< 0.001, CFI= 0.927, RMSEA= 0.065, SRMR= 0.072). Los siete factores tuvieron consistencia interna aceptable (Coeficiente a con un rango entre 0.624 y 0.746; y el Coeficiente ω entre 0.719 y 0.896). Conclusión: La Escala EMA-Enf puede ser una propuesta viable en la investigación y práctica educativa relacionada con la formación de profesionales de la enfermería.

Abstract Objective: The present work carries out an adaptation of the Academic Motivation Scale (EMA) to be used in professional nursing education (EMA-Enf) and to evaluate its psychometric properties. Materials and method: An adaptation to a Spanish version of the EMA was made for its use in the context of professional nursing education. A structured questionnaire was developed and applied to 447 Nursing undergraduate students in Michoacán, Mexico. Confirmatory factor analysis (CFA) was performed to test the fit of different models derived from Self-Determination Theory (SDT). SPSS software was used for database management and R software for model estimation considering the ordinal nature of the items. The internal consistency was evaluated through the Coefficients α and ω. Results: In the AFC, it was observed that the model of seven correlated factors proposed in the SDT achieves the best fit (χ2= 951.88 p< 0.001, CFI= 0.927, RMSEA= 0.065, SRMR= 0.072). The seven factors had acceptable internal consistency (Coefficient a with a range between 0.624 and 0.746; and the Coefficient ω between 0.719 and 0.896). Conclusion: The EMA-Enf Scale can be a viable proposal in educational research and practice related to professional nursing education.

Synthesis of gold-tin alloy nanoparticles with tunable plasmonic properties.

Plasmonic nanoparticles and nanocrystalline materials have broad applicability in catalysis, optoelectronics, sensing, and sustainability. Below, we detail a robust protocol for the synthesis of bimetallic Au-Sn nanoparticles in mild, aqueous conditions. This protocol describes the steps for synthesizing gold nanoparticle seeds, diffusing Sn into the seeds by chemical reduction, and the optical and structural analysis by UV-visible spectroscopy, X-ray diffraction, and electron microscopy. For complete details on the use and execution of this protocol, please refer to Fonseca Guzman et al.1.

Small polystyrene microplastics interfere with the breakdown of milk proteins during static in vitro simulated human gastric digestion.

Human ingestion of microplastics (MPs) is common and inevitable due to the widespread contamination of food items, but implications on the gastric digestion of food proteins are still unknown. In this study, the interactions between pepsin and polystyrene (PS) MPs were evaluated by investigating enzyme activity and conformation in a simulated human gastric environment in the presence or absence of PS MPs. The impact on food digestion was also assessed by monitoring the kinetics of protein hydrolysis through static in vitro gastric digestion of cow's milk contaminated with PS. The binding of pepsin to PS showed that the surface chemistry of MPs dictates binding affinity. The key contributor to pepsin adsorption seems to be π-π interactions between the aromatic residues and the PS phenyl rings. During quick exposure (10 min) of pepsin to increasing concentrations (222, 2219, 22188 particles/mL) of 10 µm PS (PS10) and 100 µm PS (PS100), total enzymatic activities were not affected remarkably. However, upon prolonged exposure at 1 and 2 h, preferential binding of pepsin to the small, low zeta-potential PS caused structural changes in the protein which led to a significant reduction of its activity. Digestion of cow's milk mixed with PS10 resulted in transient accumulation of larger peptides (10-35 kDa) and reduced bioavailability of short peptides (2-9 kDa) in the gastric phase. This, however, was only observed at extremely high PS10 concentration (0.3 mg/mL or 5.46E+05 particles/mL). The digestion of milk peptides, bound preferentially over pepsin within the hard corona on the PS10 surface, was delayed up to 15 min in comparison to bulk protein digestion. Intact caseins, otherwise rapidly digested, remained bound to PS10 in the hard corona for up to 15 min. This work presents valuable insights regarding the interaction of MPs, food proteins, and pepsin, and their dynamics during gastric digestion.

Scalable Strategies to Increase Efficiency and Augment Public Health Activities During Epidemic Peaks.

OBJECTIVE: Scalable strategies to reduce the time burden and increase contact tracing efficiency are crucial during early waves and peaks of infectious transmission. DESIGN: We enrolled a cohort of SARS-CoV-2-positive seed cases into a peer recruitment study testing social network methodology and a novel electronic platform to increase contact tracing efficiency. SETTING: Index cases were recruited from an academic medical center and requested to recruit their local social contacts for enrollment and SARS-CoV-2 testing. PARTICIPANTS: A total of 509 adult participants enrolled over 19 months (384 seed cases and 125 social peers). INTERVENTION: Participants completed a survey and were then eligible to recruit their social contacts with unique "coupons" for enrollment. Peer participants were eligible for SARS-CoV-2 and respiratory pathogen screening. MAIN OUTCOME MEASURES: The main outcome measures were the percentage of tests administered through the study that identified new SARS-CoV-2 cases, the feasibility of deploying the platform and the peer recruitment strategy, the perceived acceptability of the platform and the peer recruitment strategy, and the scalability of both during pandemic peaks. RESULTS: After development and deployment, few human resources were needed to maintain the platform and enroll participants, regardless of peaks. Platform acceptability was high. Percent positivity tracked with other testing programs in the area. CONCLUSIONS: An electronic platform may be a suitable tool to augment public health contact tracing activities by allowing participants to select an online platform for contact tracing rather than sitting for an interview.