On the antimicrobial properties and endurance of eugenol and 2-phenylphenol functionalized sol-gel coatings.

Preventing microbiological surface contamination in public spaces is nowadays of high priority. The proliferation of a microbial infection may arise through air, water, or direct contact with infected surfaces. Chemical sanitization is one of the most effective approaches to avoid the proliferation of microorganisms. However, extended contact with chemicals for cleaning purposes such as chlorine, hydrogen peroxide or ethanol may lead to long-term diseases as well as drowsiness or respiratory issues, not to mention environmental issues associated to their use. As a potentially safer alternative, in the present work, the efficacy and endurance of the antimicrobial activity of different sol-gel coatings were studied, where one or two biocides were added to the coating matrix resulting on active groups exposed on the surface. Specifically, the coating formulations were synthesized by the sol-gel method. Using the alkoxide route with acid catalysis a hybrid silica-titania-methacrylate matrix was obtained where aromatic liquid eugenol was added with a double function: as a complexing agent for the chelation of the reaction precursor titanium isopropoxide, and as a biocide. In addition, 2-Phenylphenol, ECHA approved biocide, has also been incorporated to the coating matrix. The antibacterial effect of these coatings was confirmed on Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). Additionally, the coatings were non cyto-toxic and displayed virucidal activity. The coating chemical composition was characterized by 29Si NMR, and ATR-FTIR. Furthermore, the thickness and the mechanical properties were characterized by profilometry and nanoindentation, respectively. Finally, the durability of the coatings was studied with tribology tests. Overall, our data support the efficacy of the tested sol-gel coatings and suggest that added features may be required to improve endurance of the antimicrobial effects on operational conditions.

Characterization of Multilayer Coupling Based on Square Complementary Split Ring Resonator for Multiport Device Implementation.

The advent of context-aware environments and related applications demands a high degree of connectivity, with new spectral bands and related radio resource management functionalities in the current 5G bands and foreseen in future 6G wireless communication systems. This, in turn, poses new challenges in the implementation of wireless transceivers and radiating systems, in terms of device integration, miniaturization and element isolation, among others. High-performance miniature devices are presented and studied in this work, aided by metamaterial-inspired complementary resonators. A single particle is used to build a single layer, double layer, double frequency resonators and power dividers. A complete characterization of each equivalent circuit is also analyzed, showing great agreement between analytical circuit models and full-wave electromagnetic simulations. By adding more particles, different diplexers and triplexers in the multi-layer configuration are proposed. The flexibility in the design is the key advantage, as all devices are easily tunable and the output lines can be built in different layers, enabling frequency scalability from RF to millimeter wave ranges. Nevertheless, they are only a sample of all possible combinations of devices that can be designed for integration in future wireless communication systems.

Caracterización de la infección urinaria y resistencia antimicrobiana en receptores de trasplante renal de un centro colombiano / Characterization of Urinary Tract Infection and Antimicrobial Resistance in Kidney Transplant Recipients from a Colombian Tertiary Center

La infección del tracto urinario (ITU) es una de las principales complicaciones postrasplante renal, los datos a nivel nacional en ese grupo poblacional son limitados. Objetivos caracterizar la microbiología de las ITU presentadas en receptores de trasplante renal (TxR) en un centro colombiano durante el periodo 2017­2019, los factores relacionados con la resistencia antimicrobiana y el impacto de la ITU en la función del injerto renal. Métodos estudio de corte transversal ejecutado mediante el análisis de la base de datos de ingresos hospitalarios por urgencias de pacientes receptores de TxR con sospecha clínica de ITU en una institución de cuarto nivel en Bogotá, Colombia. El análisis de datos se ejecutó en STATA 13.0. Resultados La ITU causó 12,69% de visitas a urgencias en pacientes trasplantados. Los microorganismos aislados fueron: Escherichia coli 52,22%, Klebsiella pneumoniae 16,67%, Pseudomonas aeruginosa 4,44%, Salmonella spp 4,44%, Proteus mirabilis 3,33%, Serratia marcescens 2,22%, Klebsiella oxytoca 2,22%, Citrobacter koseri 1,11%, Enterobacter cloacae 1,11%, otros 2,22%; El urocultivo fue negativo en 10% de los casos. El 28,39% (n:23) de gérmenes aislados fue multisensible mientras que el 71,60% (n:58) expresó algún tipo de patrón de resistencia distribuido así: 68,96% productor de betalactamasa de espectro extendido (BLEE), 15,52% productor de carbapenemasas, 12,06% productor de betalactamasa tipo IRT, 3,45% fue catalogado como multirresistente. 17,78% de los pacientes presentó criterios de urosepsis, no se registró ningún caso de mortalidad asociada a la ITU. La creatinina sérica tuvo un incremento promedio de 0,46 mg/dl durante el episodio de ITU (p: <0,0001) y el antecedente de diabetes mellitus se relacionó con la ITU causada por gérmenes resistentes (p: 0,008). Conclusiones La ITU es una causa frecuente de atención en urgencias para pacientes receptores de TxR; la Escherichia coli es el microorganismo causal más frecuente y cerca del 70% de los gérmenes aislados presentó algún patrón de resistencia antimicrobiana.

Urinary tract infection (UTI) is one of the most common complications after kidney transplantation (KTx). This study aims to characterize the microbiology of UTIs presented in KTx recipients in a Colombian tertiary center during the period 2017­2019, factors related with antimicrobial resistance and the impact of UTI on kidney graft function. Methods A cross-sectional retrospective single center study were made through the institutional database analysis of hospital admissions to the emergency room of KTx recipients with clinical suspicion of UTI. Data analysis was run on STATA 13.0. Results UTI caused 12.69% of visits to the emergency room in transplant patients during the study period. The isolated microorganisms were Escherichia coli 52.22%, Klebsiella pneumoniae 16.67%, Pseudomonas aeruginosa 4.44%, Salmonella spp 4.44%, Proteus mirabilis 3.33%, Serratia marcescens 2.22%, Klebsiella oxytoca 2.22%, Citrobacter koseroi 1.11%, others 2.22%; Urine culture was negative in 10% of cases. 28.39% (n: 23) of isolated germs were multisensitive while 71.60% (n: 58) expressed some type of resistance pattern distributed as follows: 68.96% extended spectrum beta-lactamase (ESBL) producers, 15.52% carbapenemases producers, 12.06% IRT-type beta-lactamase producers, 3.45% was classified as multi-resistant. 17.78% of patients presented criteria for urosepsis, there was no cases of mortality due to UTI. Serum creatinine had an average increase of 0.46 mg/dl during the UTI episode (p: <0.0001) and a history of diabetes mellitus was related with UTI caused by resistant germs (p: 0.008). Conclusion UTI is a frequent cause of emergency care for KTx recipients. E. coli is the most common causative microorganism and about 70% of isolated germs showed some pattern of antimicrobial resistance.

Adaptación transcultural y validación al español de la escala de movilidad funcional DEMMI (DeMorton Mobility Index) para adultos mayores / Transcultural adaptation and validation to spanish of the DEMMI functional mobility scale (DeMorton Mobility Index) for older adults

Introducción: el Índice de Movilidad de De Morton® (en inglés De Morton Mobility Index: DEMMI®) es una escala, válida y fiable para evaluar la movilidad funcional del adulto mayor. Objetivo: validar una versión en español para pacientes hospitalizados en una sala general. Material y métodos: traducción y adaptación transcultural, evaluación de la fiabilidad interobservador y validación de criterio explorando la correlación entre los índices DEMMI y Barthel® al ingreso hospitalario y también entre la percepción subjetiva del cambio en la movilidad por parte del propio paciente y la del puntaje DEMMI, y además evaluando la asociación entre este y el grado de acompañamiento requerido en el egreso hospitalario (n = 87). Su consistencia interna fue evaluada mediante los coeficientes de Kuder y Richardson (KR) y de Cronbach (n = 104). Resultados: la correlación entre los puntajes DEMMI y Barthel fue buena (Spearman's Rho = 0,78: p ≤ 0,0001), mientras que la correlación entre la percepción del paciente respecto del cambio en su movilidad y la variación en el puntaje DEMMI fue moderada (Spearman's Rho = 0,50; p < 0,0001). Quienes fueron dados de alta con alto nivel de acompañamiento habían tenido al ingreso un puntaje DEMMI inferior (28,1; IC 95%, 24,9 a 31,3) al de quienes no lo requirieron (48; 44,4 a 53,0). La consistencia interna fue adecuada (KR = 0,827 y Cronbach = 0,745; Pearson's Rho = 0,7885; p < 0,00001). Conclusión: la consistencia interna y la fiabilidad interobservador de la versión en español del puntaje DEMMI son buenas, mientras que sus cambios tienen buena correlación con los percibidos por los propios pacientes. Consideramos que puede ser usado como un elemento más para estimar al momento del ingreso hospitalario, el grado de acompañamiento que requerirán al ser dados de alta. (AU)

Introduction: the De Morton Mobility Index (DEMMI) is a valid and reliable scale to evaluate the functional mobility of the elderly. Aim: validate a Spanish version for hospitalized patients in a general ward. Material and methods: translation and cross-cultural adaptation, evaluation of inter-observer reliability and criterion validation exploring the correlation between DEMMI and Barthel scores at hospital admission and also between the subjective perception of the change in mobility by the patient himself and that of DEMMI score, and also, evaluating the association between DEMMI and the degree of support required at hospital discharge (n = 87). Its internal consistency was evaluated using Kuder-Richardson (KR) and Cronbach (n = 104) coefficients. Results: correlation between DEMMI and Barthel scores was good (Spearman's Rho = 0.78: p < = 0.0001), while correlation between patient's perception of change in mobility and variation in DEMMI score was moderate (Spearman's Rho = 0.50; p < 0.0001). Those discharged with a high level of support had a lower DEMMI score upon admission (28.1; 95% CI 24.9 to 31.3) than those who didn´t require it (48; 44.4 to 53.0). Internal consistency was adequate (KR = 0.827 and Cronbach = 0.745; Pearson's Rho = 0.7885; p < 0.00001). Conclusion: internal consistency and interobserver reliability of the Spanish version of DEMMI score are good, while its changes correlate well with those perceived by the patients themselves. We consider that it can be used as another element to estimate at hospital admission, the degree of support they will require upon discharge. (AU)

First case of Aspergillus caelatus airway colonization in a Chronic Obstructive Pulmonary Disease patient.

BACKGROUND: During a cross-sectional study on allergic aspergillosis in Chronic Obstructive Pulmonary Disease patients in Bogotá, Colombia, we reported the case of a 65-year-female patient with GOLD 2011 D classification, presenting dyspnea at the time of visit and aspergillus in repeated sputum cultures. METHODS: The isolate was identified at the section level based on macroscopic and microscopic characteristics and gene sequencing was used for precise molecular identification. Antifungal sensibility was determined by Sensititre YeastOne™ while virulence was assessed using a Galleria mellonella larvae model. RESULTS: The clinical isolate was first identified as Aspergillus section Flavi and sequencing of ß-tubulin and calmodulin genes, in addition to the identification of alfR (aflatoxin regulator) gene, allowed the undoubted identification of the clinical isolate as Aspergillus caelatus. It exhibited virulence in G. mellonella similar to A. flavus and a high in vitro susceptibility against all antifungals except for amphotericin B. CONCLUSION: This is the first human case of airway colonization attributed to A. caelatus. Resistance pattern justified the interest to discriminate this cryptic species.

Abscisic Acid Regulation of Root Hydraulic Conductivity and Aquaporin Gene Expression Is Crucial to the Plant Shoot Growth Enhancement Caused by Rhizosphere Humic Acids.

The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface.

Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status.

Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the plant-based methods to determine it suffer from several inconveniences, mainly caused by the necessity of destructive sampling or of alteration of the plant organ due to contact installation. The aim of this work is to test if terahertz (THz) time domain reflectance measurements made on the grapevine trunk allows contactless monitoring of plant status. The experiments were performed on a potted 14-years-old plant, using a general purpose THz emitter receiver head. Trunk THz time-domain reflection signal proved to be very sensitive to changes in plant water availability, as its pattern follows the trend of soil water content and trunk growth variations. Therefore, it could be used to contactless monitor plant water status. Apart from that, THz reflection signal was observed to respond to light conditions which, according to a specifically designed girdling experiment, was caused by changes in the phloem. This latter results opens a promising field of research for contactless monitoring of phloem activity.