Development and validation study of compact biophotonic platform for detection of serum biomarkers.

The application of advances in personalized medicine requires the support of in vitro diagnostic techniques aimed at the accurate, fast, sensitive, and precise determination of selected biomarkers. Herein, a novel optical centrifugal microfluidic device is developed for clinical analysis and point-of-care diagnostics. Based on compact disc technology, the integrated biophotonic system enables multiple immunoassays in miniaturized mode. The disposable microfluidic discs are made in cyclic olefin copolymer (COP), containing arrays of immobilized probes. In the developed approach, up to six patient samples can each be tested simultaneously. A portable instrument (<2 kg) controls the assay and the high-sensitive reproducible optical detection in transmission mode. Also, the instrument incorporates specific functionalities for personalized telemedicine. The device (analytical method, disc platform, reader, and software) has been validated to diagnose IgE-mediated drug allergies, such as amoxicillin and penicillin G. The total and specific IgE to ß-lactam antibiotics were determined in human serum from patients (25 µL). The excellent analytical performances (detection limit 0.24 ng/mL, standard deviation 7-20 %) demonstrated that the developed system could have the potential for a broader impact beyond the allergy field, as it applies to other IVD tests.

Coinfección bacteriana en el paciente COVID-19 crítico: incidencia, impacto y necesidad de tratamiento antibiótico / Bacterial coinfection in the critically-ill COVID-19 patient: incidence, impact and need for antimicrobial therapy

Objetivos. Evaluar la frecuencia de coinfección bacteriana al ingreso en UCI en pacientes con neumonía por SARS-CoV-2, su microbiología e impacto en el pronóstico. El objetivo secun dario fue identificar factores de riesgo de coinfección al ingreso. Métodos. Estudio retrospectivo, se incluyeron pacientes con neumonía por SARS-CoV-2 ingresados en UCI. Definimos coinfección bacteriana por síntomas respiratorios, datos radioló gicos, resultados microbiológicos positivos y clínicamente signi ficativos en muestras obtenidas en las primeras 48 h de ingreso y/o una determinación de procalcitonina ≥ 0,5 ng/mL en las pri meras 48 h. Evaluamos variables demográficas, comorbilidades, datos de la infección por SARS-CoV-2, scores de gravedad, tra tamientos recibidos, necesidad de soporte respiratorio y resulta dos (estancia y mortalidad durante el ingreso en UCI y hospital). Resultados. Se analizaron 182 pacientes, 62 (34.1%) con coinfección bacteriana. La microbiología más frecuente fue S. pneumoniae y M. pneumoniae. El 96.1% de los pacientes re cibieron antibioterapia al ingreso, 98,9% corticoides, 27,5% tocilizumab y 7,7% remdesivir. El 85.7% necesitó ventilación mecánica invasiva. La puntuación en SOFA (OR: 1,315, IC 95% 1,116-1,548) y el retraso en el ingreso en UCI (OR: 0,899, IC 95% 0,831-0,972) se relacionaron con el riesgo de coinfección. La coinfección bacteriana aumenta el riesgo de muerte en el hospital (OR 2,283; IC 95% 1,011-5,151; p=0,047). Conclusiones. La coinfección bacteriana es frecuente en pacientes COVID ingresados en UCI y aumenta el riesgo de muerte. No es posible identificar con seguridad, en el momen to de ingreso, qué pacientes no se benefician de tratamiento antibiótico (AU)

ion upon ICU admission in SARS-CoV-2 pneumonia patients, its microbiology, and impact on prognosis.The secondary ob jective was to identify risk factors for coinfection on admis sion. Methods. Retrospective study, including patients with SARS-CoV-2 pneumonia admitted to the ICU.We defined bac terial coinfection by respiratory symptoms, radiological data, positive and clinically significant microbiological results in samples obtained in the first 48 h of admission and/or a de termination of procalcitonin ≥ 0.5 ng/mL in the first 48 h.We evaluated demographic variables, comorbidities, SARS-CoV-2 infection data, severity scores, treatments received, need for respiratory support and outcomes (ICU and hospital mortality). Results. A total of 182 patients were analyzed, 62 (34.1%) with bacterial coinfection.The most frequent microbiology was S. pneumoniae and M. pneumoniae.96.1% of the patients re ceived antibiotic therapy on admission, 98.9% corticosteroids, 27.5% tocilizumab, and 7.7% remdesivir.85.7% required inva sive mechanical ventilation.The SOFA score (OR: 1.315, 95% CI 1.116-1.548) and the delay in ICU admission (OR: 0.899, 95% CI 0.831-0.972) were related to the risk of coinfection.Bacterial coinfection increases the risk of death in hospital (OR 2.283; 95% CI 1.011.5.151; p=0.047). Conclusions. Bacterial coinfection is common in COVID patients admitted to the ICU and increases the risk of death.It is not possible to identify with certainty, at the time of admis sion, which patients do not benefit from antibiotic treatment (AU)

Surface Bragg gratings of proteins patterned on integrated waveguides for (bio)chemical analysis.

The incorporation of biomacromolecules onto silicon waveguiding microstructures constitutes a growing trend that pushes towards compact and miniaturized biosensing systems. This paper presents the integration of one-dimensional periodic nanostructures of proteins on the surface of micrometric silicon waveguides for transducing binding events between biomacromolecules. The study demonstrates this new bioanalytical principle by experimental results and theoretical calculations, and proves that rib waveguides (1--1.6-µm width) together with protein gratings (495--515-nm period) display suitable spectral responses for this optical biosensing system. Protein assemblies of bovine serum albumin are fabricated on the surface of silicon nitride waveguides, characterized by electron microscopy, and their response is measured by optical frequency domain reflectometry along the fabrication process and the subsequent stages of the biorecognition assays. Detection and quantification limits of 0.3 and 3.7 µg·mL-1, respectively, of specific antibodies are inferred from experimental dose-response curves. Among other interesting features, the results of this study point towards new miniaturized and integrated sensors for label-free bioanalysis.

Surface Micro-Patterned Biofunctionalized Hydrogel for Direct Nucleic Acid Hybridization Detection.

The present research is focused on the development of a biofunctionalized hydrogel with a surface diffractive micropattern as a label-free biosensing platform. The biosensors described in this paper were fabricated with a holographic recording of polyethylene terephthalate (PET) surface micro-structures, which were then transferred into a hydrogel material. Acrylamide-based hydrogels were obtained with free radical polymerization, and propargyl acrylate was added as a comonomer, which allowed for covalent immobilization of thiolated oligonucleotide probes into the hydrogel network, via thiol-yne photoclick chemistry. The comonomer was shown to significantly contribute to the immobilization of the probes based on fluorescence imaging. Two different immobilization approaches were demonstrated: during or after hydrogel synthesis. The second approach showed better loading capacity of the bioreceptor groups. Diffraction efficiency measurements of hydrogel gratings at 532 nm showed a selective response reaching a limit of detection in the complementary DNA strand of 2.47 µM. The label-free biosensor as designed could significantly contribute to direct and accurate analysis in medical diagnosis as it is cheap, easy to fabricate, and works without the need for further reagents.

Patterned Biolayers of Protein Antigens for Label-Free Biosensing in Cow Milk Allergy.

This paper focuses on creating one-dimensional diffractive grooved structures of antigen proteins on glass substrates for the label-free detection of antibodies to dairy allergens. In particular, the fabrication of protein structures is carried out by combining microcontact printing with physisorption, imines coupling, and thiol-ene click chemistry. The work first sets up these patterning methods and discusses and compares the main aspects involved in them (structure, biolayer thickness, functionality, stability). Homogeneous periodic submicron structures of proteins are created and characterized by diffractive measurements, AFM, FESEM, and fluorescence scanning. Then, this patterning method is applied to proteins involved in cow milk allergy, and the resulting structures are implemented as optical transducers to sense specific immunoglobulins G. In particular, gratings of bovine serum albumin, casein, and ß-lactoglobulin are created and assessed, reaching limits of detection in the range of 30-45 ng·mL-1 of unlabeled antibodies by diffractive biosensing.

Denaturing for Nanoarchitectonics: Local and Periodic UV-Laser Photodeactivation of Protein Biolayers to Create Functional Patterns for Biosensing.

The nanostructuration of biolayers has become a paradigm for exploiting nanoscopic light-matter phenomena for biosensing, among other biomedical purposes. In this work, we present a photopatterning method to create periodic structures of biomacromolecules based on a local and periodic mild denaturation of protein biolayers mediated by UV-laser irradiation. These nanostructures are constituted by a periodic modulation of the protein activity, so they are free of topographic and compositional changes along the pattern. Herein, we introduce the approach, explore the patterning parameters, characterize the resulting structures, and assess their overall homogeneity. This UV-based patterning principle has proven to be an easy, cost-effective, and fast way to fabricate large areas of homogeneous one-dimensional protein patterns (2 min, 15 × 1.2 mm, relative standard deviation ≃ 16%). This work also investigates the implementation of these protein patterns as transducers for diffractive biosensing. Using a model immunoassay, these patterns have demonstrated negligible signal contributions from non-specific bindings and comparable experimental limits of detection in buffer media and in human serum (53 and 36 ng·mL-1 of unlabeled IgG, respectively).

Parental Involvement in Homework During Covid-19 Confinement.

BACKGROUND: The purpose of this study was to compare parents' involvement in students' homework during COVID-19 confinement and their involvement in normal circumstances. METHOD: 628 parents of elementary and high school students completed a questionnaire about their family and family involvement in their children's homework. To address the objective, data were examined using mean differences and analysis of variance. RESULTS: As predicted, the COVID-19 situation led to more time spent doing homework for students, as well as higher levels of conflict and stress within the family. In addition, parents reported having increased their homework management during confinement in terms of emotional and motivational support for their children compared to normal circumstances. Finally, the data showed more conflicts and family involvement in the families of children with special needs compared to families of children without special needs. CONCLUSIONS: The time spent in confinement posed many challenges to families' routines and the data indicated a lack of resources available for families to manage their children's tasks, as well as an increase in family stress and conflicts.

Validation of the Shortened Version of the Metacognitive Awareness Inventory in Spanish Uiversity Students.

BACKGROUND: The Metacognitive Awareness Inventory (MAI) is used all over the world to identify metacognitive components that are relevant to learning. However, there is not enough evidence confirming its factorial structure or the suitability of its Shortened Version, proposed by various authors. Also, to date, the MAI has not been validated in the Spanish context. METHOD: After adapting the MAI to Spanish, it was administered to 1076 university students from different regions of Spain. Different structures of the MAI Shortened Version, with 19 items, were compared with the structures of the original 52-item MAI. Indexes of validity and reliability were analyzed, considering the factorial structure and relationships to other validated questionnaires. RESULTS: Only the MAI Shortened Version that differentiates between knowledge and regulation of cognition achieved a good fit. These two scales showed good convergent and divergent validity, high criterion validity in relation to academic achievement, high test- retest reliability, and high internal reliability. CONCLUSIONS: results support the traditional differentiation between knowledge of cognition and regulation of cognition, but only for the Shortened Version of the MAI. This instrument allows quick evaluations and identification of these components in Spanish contexts with adequate metric properties.

Vitamin E protects from lipid peroxidation during winter stress in the seagrass Cymodocea nodosa.

MAIN CONCLUSION: Adjustments in the antenna size and α-tocopherol contents provide protection from sustained damage in leaves of a seagrass, while low vitamin E contents appear to be enough to protect rhizomes (which appear to be more cold tolerant than leaves). Despite low temperatures can adversely affect the proper growth and development of marine angiosperms, by, among other processes, increasing reactive oxygen species production and causing oxidative damage to lipid membranes, the role of vitamin E in seagrasses, such as Cymodocea nodosa has not been explored thus far. Here, we aimed to better understand the possible role of this chain-breaking (peroxyl radical-trapping) antioxidant in response to low temperatures, and most particularly in relation to the occurrence of photo-inhibition and lipid peroxidation. Low temperatures caused an important desiccation of leaves, but not of rhizomes, which were much more tolerant to cold stress than leaves. Cold stress during winter was associated with chlorophyll loss and transient photo-inhibition, as indicated by reversible reductions in the Fv/Fm ratio. Adjustments in pigment antenna size and vitamin E contents per unit of chlorophyll during winter may help protect the photosynthetic apparatus from sustained photo-inhibitory damage and lipid peroxidation events in leaves. Rhizomes also accumulated significant amounts of vitamin E, although to a much lesser extent than leaves, and kept protected from lipid peroxidation during winter, as indicated by malondialdehyde contents, a product from secondary lipid peroxidation. It is concluded that vitamin E can help protect both leaves and rhizomes from lipid peroxidation, although cold stress during winter can cause transient photo-inhibition of the photosynthetic apparatus, in C. nodosa.

Parental Involvement in Homework During Covid-19 Confinement / Implicación Parental en los Deberes Escolares Durante el Confinamiento por Covid-19

Background: The purpose of this study was to compare parents’ involvement in students’ homework during COVID-19 confinement and their involvement in normal circumstances. Method: 628 parents of elementary and high school students completed a questionnaire about their family and family involvement in their children’s homework. To address the objective, data were examined using mean differences and analysis of variance. Results: As predicted, the COVID-19 situation led to more time spent doing homework for students, as well as higher levels of conflict and stress within the family. In addition, parents reported having increased their homework management during confinement in terms of emotional and motivational support for their children compared to normal circumstances. Finally, the data showed more conflicts and family involvement in the families of children with special needs compared to families of children without special needs. Conclusions: The time spent in confinement posed many challenges to families’ routines and the data indicated a lack of resources available for families to manage their children’s tasks, as well as an increase in family stress and conflicts.(AU)

Antecedentes: El propósito de este estudio fue comparar la implicación de los padres en los deberes de los hijos durante el período de confinamiento por Covid-19 con la implicación en circunstancias normales. Método: 628 padres de alumnos de Primaria y Secundaria respondieron a cuestiones sobre características de la familia y su implicación en los deberes escolares de los hijos. Para abordar el objetivo, los datos se estudiaron mediante diferencias de medias y análisis de varianza. Resultados: La situación de confinamiento llevó a que los estudiantes dedicaran más tiempo a hacer los deberes, así como a niveles más altos de conflictos y estrés dentro de la familia. Además, los padres informaron haber aumentado su implicación en los deberes en cuanto a apoyo emocional y motivacional dedicado a sus hijos en comparación con las circunstancias normales. Finalmente, se obtuvieron datos que muestran mayor cantidad de conflictos y estrés en familias con niños con necesidades especiales. Conclusiones: El confinamiento planteó muchos desafíos para las rutinas de las familias, observándose una falta de recursos disponibles de las familias para implicarse adecuadamente en las tareas escolares de sus hijos, así como un aumento del estrés y los conflictos familiares.(AU)