Electrochemical SERS spectra of isonicotinic acid analyzed under a photoinduced charge-transfer mechanism

Isonicotinic (IN) acid is one of the three monocarboxilic derivatives of pyridine in which the acid group is located in para-position of the heterocyclic ring. It is a weak acid (pK2=4.86) and therefore, it is not completely ionized in neutral aqueous solutions, being the zwitterion and the anion the majority chemical species at neutral pH. In acidic solutions (pK1=1.84) the pyridinic nitrogen atom can be protonated yielding a third chemical species with positive charge [1]. In addition, IN acid shows two functional centres that can interact with the silver metallic surface such as the carboxilate group and the aromatic nitrogen atom. Therefore, the analysis of the SERS spectra of IN has been focused on identifying the chemical species adsorbed on the silver surface and its centre of interaction by considering the participation of a photoinduced charge-transfer (CT) mechanism in each particular SERS record as we have previously detected in the SERS of pyridine derivatives [2]. SERS spectra of the IN acid (5x10-3 M) have been recorded on silver at electrode potentials ranging from 0.00 up to -1.00 V and at different pH by using 0.1 M Na2SO4 aqueous solution as electrolyte. The figure shows the SERS recorded at basic pH. The experimental set up is described elsewhere and the excitation line of 514.5 nm wavelength was used. [2]. The detection of the presence of CT processes, which are similar to resonance Raman, requires to carry out quantum mechanical calculations [2].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A case of intoxication due to a highly cytotoxic Bacillus cereus strain isolated from cooked chicken

Outbreaks of Bacillus cereus infection/intoxication are not commonly reported because symptoms are often mild, and the disease is self-limiting. However, hypervirulent strains increase health risks. We report a case, which occurred in Argentina, of severe food The studied strain was highly cytotoxic, showed high ability to detach Caco-2 cells and was positive for the hblA, hblB, and hblC genes of the hbl complex, bceT, entS and ces. As it is considered that B. cereus emetic cluster evolved from a panmictic population of diarrhoeal strains, B. cereus MVL2011 could constitute an intermediate strain between diarrhoeal and emetic strains.Prepint aceptado el 14 de agosto de 2014 para su publicación

SERS study of thiocarbonyl compounds adsorbed on metal nanoparticles

Thiocarbonyl compounds have been reported to exhibit interesting biological and pharmacological properties but they are many often characterized by their toxicological effects. However the chemistry of thiobenzoic acid (TBA) and thiobenzamide (TB) has not been fully studied yet. Some of the biological studies of TBA are related to the tautomerism of thiocarboxylic acids and the important role that the -C(=O)-S and -C(=S)-O functional groups play in the catalytic activities of enzymes such as cysteine or serine proteases.1 On the other hand, TB and derivatives are well known hepatotoxins and have been used as inhibitor in enzymatic reactions and in pharmacy due to their microbial activity.2 From a chemical point of view, thiocarboxylates are an interesting type of molecules having two different donor atoms, a soft sulfur donor atom and a hard oxygen donor one. The presence of these unlike groups can lead to the bonding with metal surfaces. Likewise the interaction of thiobenzamide and their derivatives with metals is of great interest because both the sulfur and nitrogen atoms are also able to coordinate with the surface. Therefore the high affinity of these molecules for metal surfaces makes them suitable SERS target adsorbates. Taking advantage of the fact that SERS spectroscopy is both surface selective and highly sensitive we have attempted to determine the molecular structure of TBA and TB once they are adsorbed on the metal. The main objective of this work is focussed on discussing the observed vibrational wavenumber shifts of TBA and TB upon adsorption on silver nanoparticles. In this work the SERS substrates have been prepared by using different colloidal silver solutions according to the method described by Creighton et al.3 and Leopold and Lendl.4 The analysis of the vibrational wavenumbers shifts of the Raman and SERS spectra allow us to know the adsorption process (Figure 1). In the case of TBA, the wavenumber of the SERS band assigned to (C=O) vibrational mode shows an important blue shift up to 40 cm-1 with respect to the Raman whereas the (C-S) band undergoes a red shift up to 40 cm-1. These results suggest a unidentate coordination of TBA to the silver surface through the sulfur atom. On the other hand, the SERS band assigned in the case of TB to Amide III (mainly (CN)) exhibits a significant blueshift up to 41 cm-1, and the SERS band assigned to Amide I (mainly (CS)) shows a red shift up to 11 cm-1. These wavenumber shifts indicate that TB interacts to the silver surface through the sulfur atom. Interestingly, in previous SERS studies of pyridinecarboxamides and benzamide we have observed that some SERS bands assigned to 1;ring, Amide I (mainly (C=O)) and Amide III (mainly C-N)) show wavenumber shifts of +50, -50 and +10 cm-1, respectively, which were attributed to the deprotonation of carboxamide group.5,6 Finally, in order to verify experimental results DFT calculations have been carried out for different silver complexes of TBA and TB concluding that the unidentate coordination is the most likely interaction of both of them.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effect of the electrode potential on surface-enhanced Raman intensities of 2-methylpyrazine

The effect of the electrode potential on Surface Enhanced Raman Scattering (SERS) intensities of 2-methylpyrazine (2MP) recorded under resonant charge transfer (CT) conditions is analyzed by using a simple theoretical model [1] in which the macroscopic surface charge in the metal is modeled by several metallic clusters with different number of silver atoms (n) and charges (q), [Agn]q. Two and three linear silver atoms with zero and positive and negative charges, respectively, bounded to the 2MP through the nitrogen atom, have been taking into account.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

BIENESTAR PSICOSOCIAL DEL ADULTO MAYOR DURANTE LA PANDEMIA COVID-19 EN LA COMUNIDAD DE PATUTAN PROVINCIA DE COTOPAXI

Introducción: La COVID-19 es altamente contagiosa lo que le transformó en pandemia rápidamente, además de los efectos en la salud orgánica, ha provocado una serie de efectos sociales, psicológicos y económicos sin precedentes en todo el mundo. La salud mental es un aspecto que se ha visto negativamente afectado sobre todo en los adultos mayores, que son susceptibles tanto por su fragilidad emocional como por la vulnerabilidad física, que conlleva al desarrollo de la forma grave. Objetivo: Identificar el bienestar psicosocial en los adultos mayores durante la pandemia COVID-19 en la comunidad de Patutan, de la Provincia de Cotopaxi/Ecuador. Método: Se realizó un estudio cuantitativo, descriptivo y transversal, en el periodo enero-julio de 2021, con una muestra censal de 58 de adultos mayores. Se utilizó la escala de Bienestar Psicológico para Adultos (BIEPS-A) de Casullo, instrumento validado con coeficiente alfa de Cronbach de 0,8; dirigido a determinar el nivel de bienestar psicosocial, compuesto por 13 ítems en cinco dimensiones Aceptación de sí mismo, Control de situaciones, Autonomía, Vínculos psicosociales y Proyectos. Resultados: Se encontró que el 57% tiene un nivel medio de bienestar psicológico, seguido del 29% con un nivel bajo y por último con 14% un nivel alto psicosocial. La dimensión con mayor desacuerdo es los vínculos psicosociales. Conclusiones: La COVID-19 ha afectado a la salud mental y bienestar psicosocial en la población de adultos mayores, reflejando problemas de estrés, falta del vínculo familiar, sentido de aislamiento y pérdida del propósito de vida.   Palabras clave: anciano, COVID-19, salud, salud mental   ABSTRACT   Introduction: The COVID-19 disease is highly contagious, which quickly transformed it into a pandemic, in addition to the effects on organic health, it has caused a series of unprecedented social, psychological and economic effects throughout the world. Mental health is an aspect that has been negatively affected, especially in older adults, who are susceptible both because of their emotional fragility and their physical vulnerability, leading to the development of the severe form. Objective: To identify psychosocial well-being in older adults during the COVID-19 pandemic in the community of Patutan, in the Province of Cotopaxi/Ecuador. Method: A quantitative, descriptive and cross-sectional study was carried out in the period January-July 2021, with a census sample of 58 older adults. The Casullo Adult Psychological Well-being Scale (BIEPS-A) was used, a validated instrument with a Cronbach's alpha coefficient of 0.8; aimed at determining the level of psychosocial well-being, composed of 13 items in five dimensions Self-acceptance, Situation control, Autonomy, Psychosocial ties and Projects. Results: It was found that 57% have a medium level of psychological well-being, followed by 29% with a low level and finally 14% with a high psychosocial level. The dimension with the greatest disagreement is that of psychosocial ties. Conclusions: COVID-19 has affected mental health and psychosocial well-being in the older adult population, reflecting stress problems, family disengagement, a feeling of isolation and loss of purpose in life.   Keywords: older adults, COVID-19, health, mental healt

Large-Scale smart grids as system of systems

Smart Grids are advanced power networks that introduce intelligent management, control, and operation systems to address the new challenges generated by the growing energy demand and the appearance of renewal energies. In the literature, Smart Grids are presented as an exemplar SoS: systems composed of large heterogeneous and independent systems that leverage emergent behavior from their interaction. Smart Grids are currently scaling up the electricity service to millions of customers. These Smart Grids are known as Large-Scale Smart Grids. From the experience in several projects about Large-Scale Smart Grids, this paper defines Large-Scale Smart Grids as a SoS that integrate a set of SoS and conceptualizes the properties of this SoS. In addition, the paper defines the architectural framework for deploying the software architectures of Large-Scale Smart Grid SoS

In vitro interaction between <i>Bacillus megaterium</i> strains and Caco-2 cells

To further our understanding of the virulence potential of Bacillus megaterium strains, cell association and invasion assays were conducted in vitro by infecting human enterocytes (Caco-2 cells) with 53 strains of this bacterium isolated from honey. Two series of experiments were performed: (i) necrosis and cell detachment assays with the supernatants of bacterial culture fi ltrates from 16-h cultures and (ii) adhesion/invasion assays in which cultured enterocytes incubated with bacteria from 3-h cultures were resuspended in Dulbecco’s modifi ed Eagle’s medium and chloramphenicol. The detachment of Caco-2 cells was evaluated by staining the cells with crystal violet. Necrosis was assessed by fl uorescence microscopy of cells labeled with propidium iodide. Association (adhesion plus invasion) was determined by plate counts and invasion in an aminoglycoside protection assay. The results showed that spent culture supernatants detached and necrotized Caco-2 cells in a strain-dependent manner. Seven out of 53 B. megaterium fi ltered culture supernatants caused complete cell detachment. Suspensions of these same bacterial strains adhered and invaded enterocytes in 2-h infection experiments. To our knowledge, this is the fi rst report on the interaction between B. megaterium and intestinal epithelial Caco-2 cells.Facultad de Ciencias Agrarias y Forestale

Effect of Storage Conditions on Physicochemical Characteristics and Phenolic Compounds of Eggplant (Solanum melongena L.)

High demand for fresh fruit and vegetables requires the implementation of techniques to extend the shelf life of these highly perishable products. A widely used method for this purpose is the refrigeration; however, it is known that most of the vegetables preserved in this way evidence chilling injury signs during storage. Eggplants cv C029 recently harvested were stored at 13°C packed into low-density polyethylene bags either with perforations (PPB), vacuum packaged (VPB), or unpacked during 5, 10, 15 and 20 days to evaluate the effect of chilling on physicochemical characteristics and visual appearance. Unpacked Eggplants presented remarkable chilling injury symptoms, losing its commercial quality before 10d of storage. Fruit stored in VPB showed discoloration affecting visual appearance but maintains the phenolic compounds and avoided pulp and seeds browning. Eggplants packed in PPB showed the best results in this work, preserving overall characteristics during 15d

A case of intoxication due to a highly cytotoxic <i>Bacillus cereus</i> strain isolated from cooked chicken

Outbreaks of Bacillus cereus infection/intoxication are not commonly reported because symptoms are often mild, and the disease is self-limiting. However, hypervirulent strains increase health risks. We report a case, which occurred in Argentina, of severe food The studied strain was highly cytotoxic, showed high ability to detach Caco-2 cells and was positive for the hblA, hblB, and hblC genes of the hbl complex, bceT, entS and ces. As it is considered that B. cereus emetic cluster evolved from a panmictic population of diarrhoeal strains, B. cereus MVL2011 could constitute an intermediate strain between diarrhoeal and emetic strains.Facultad de Ciencias Agrarias y Forestale

Effects of a Clinical Simulation-Based Training Program forNursing Students to Address Social Isolation and Loneliness inthe Elderly: A Quasi-Experimental Study

©2023. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published, version of a Published Work that appeared in final form in Healthcare. To access the final edited and published work see https://doi.org/10.3390/healthcare11182587Introduction: The population of older adults is rapidly increasing worldwide, presentingboth prospects and complexities for society and healthcare professionals to maximize the functionalcapacity of this age group. Social isolation and loneliness significantly affect this population. Theobjective was to determine the effectiveness, satisfaction, and perceptions of the simulation-basededucation practices of a training program for nursing students, which was created to palliate thesocial isolation and loneliness of older adults. Method: A quasi-experimental study was conductedwith nursing students who participated in an online training program using teleservice based on high-fidelity clinical simulation. The program included asynchronous theoretical training and synchronouspractical training using an online platform. Five scenarios were designed using simulated phonecalls to address the social isolation and loneliness of older adults. Results: Twenty-five nursingstudents participated in the program, and they had a mean age of 27.44, with 76% of them beingwomen. After the training program, the participants showed statistically significant improvements(p< 0.05) with respect to their knowledge and attitudes towards older adults, and the programwas adapted to the best educational practices in simulations. Conclusions: Simulation-based onlinetraining efficiently improved the knowledge and attitudes of nursing students towards older adults,improving their ability to address social isolation and loneliness. The high satisfaction and adhesion tothe best educational practices underline the usefulness of high-fidelity online simulations, especiallyin situations in which face-to-face training is not feasible, and accessibility and equilibrium could beguaranteed between work and personal life