Receptor Binding Domain (RBD) Structural Susceptibility in the SARS-CoV-2 Virus Spike Protein Exposed to a Pulsed Electric Field

SARS-CoV-2 is responsible for causing the Coronavirus disease 2019 (COVID-19) pandemic, which has so far infected more than thirty million people and caused almost a million deaths. For this reason, it has been a priority to stop the transmission of the outbreak through preventive measures, such as surface disinfection, and to establish bases for the design of an effective disinfection technique without chemical components. In this study, we performed in silico analysis to identify the conformational alterations of the SARS-CoV-2 Spike Receptor Binding Domain (RBD) caused by the effect of a pulsed electric field at two different intensities. We found that both stimuli, especially the one with the highest angular frequency and amplitude, modified the electrical charge distribution in the RBD surface and the number of hydrogen bonds. Moreover, the secondary structure was significantly affected, with a decrease of the structured regions, particularly the regions with residues involved in recognizing and interacting with the receptor ACE2. Since many regions suffered conformational changes, we calculated RMSF and ΔRMSF to identify the regions and residues with larger fluctuations and higher flexibility. We found that regions conformed by 353-372, 453-464, and 470-490 amino acid residues fluctuate the most, where the first is considered a therapeutic target, and the last has alreadybeen characterized for its flexibility. Our results indicate that a pulsed electric field can cause loss of stability in the Spike-RBD, and we were able to identify the vulnerable sites to be used as a starting point for the development of viral inhibition or inactivation mechanisms

Rice straw-based activated carbons doped with SiC for enhanced hydrogen adsorption

Activated carbons (ACs) based on rice straw (RS) were synthesised using potassium carbonate as activating agent at three different K2CO3/RS weight ratios. Morphological, chemical, structural as well as textural characterisations were carried out in order to establish relationships between the physicochemical properties of the materials and their hydrogen adsorption capacities. The ACs contained potassium and silicon as the main impurities. Si was identified by XRD in both phases of silicon dioxide and silicon carbide. The presence of SiC was particularly surprising due to the rather low activation temperature, much lower than what is usually required for SiC synthesis. ACs exhibited well-developed surface areas (approximatively 2000–2100 m2 g-1) and high micropore volumes, making them suitable for hydrogen storage applications. RS-based ACs showed higher hydrogen storage capacities than those previously obtained with KOH-activated sucrose. The latter exhibited hydrogen uptakes (excess, 10 MPa, 298 K) up to 0.55 wt. %, whereas 0.65 wt. % was measured for RS-based ACs in the same conditions. The higher hydrogen capacities and isosteric heats of adsorption found here were attributed to the presence of SiC

Capacity for LDL (Low-Density Lipoprotein) Retention Predicts the Course of Atherogenesis in the Murine Aortic Arch.

BACKGROUND To cause atherosclerosis, LDLs (low-density lipoproteins) must first pass through the endothelium and then become retained in the arterial matrix. Which of these two processes is rate-limiting and predicts the topography of plaque formation remains controversial. To investigate this issue, we performed high-resolution mapping of LDL entry and retention in murine aortic arches before and during atherosclerosis development. METHODS Maps of LDL entry and retention were created by injecting fluorescently labeled LDL followed by near-infrared scanning and whole-mount confocal microscopy after 1 hour (entry) and 18 hours (retention). By comparing arches between normal mice and mice with short-term hypercholesterolemia, we analyzed changes in LDL entry and retention during the LDL accumulation phase that precedes plaque formation. Experiments were designed to secure equal plasma clearance of labeled LDL in both conditions. RESULTS We found that LDL retention is the overall limiting factor for LDL accumulation but that the capacity for LDL retention varied substantially over surprisingly short distances. The inner curvature region, previously considered a homogenous atherosclerosis-prone region, consisted of dorsal and ventral zones with high capacity and a central zone with low capacity for continued LDL retention. These features predicted the temporal pattern of atherosclerosis, which first appeared in the border zones and later in the central zone. The limit to LDL retention in the central zone was intrinsic to the arterial wall, possibly caused by saturation of the binding mechanism, and was lost upon conversion to atherosclerotic lesions. CONCLUSIONS Capacity for continued LDL retention varies over short distances and predicts where and when atherosclerosis develops in the mouse aortic arch.This study was supported by grants from the Ministerio de Economía, Industria y Competitividad (MEIC) with cofunding from the European Regional Development Fund (SAF2016-75580-R and PID2019-108568RB-I00), the Novo Nordisk Foundation (NNF17OC0030688) and the La Caixa Health Research Programme (HR20-00075, AtheroConvergence). V. Labrador-Cantarero is supported by FEDER “Una manera de hacer Europa” for the project In Vivo Advanced Nanoscopy at the ICTS–ReDib–TRIMA–CNIC. CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación, and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

Iridium oxide (IV) nanoparticle-based lateral flow immunoassay

Lateral flow biosensors are paper-based devices that allow the detection of different types of analytes with quickness, robustness and selectivity, without leaving behind paper sensors benefits as low-cost, recyclability and sustainability. Nanomaterials have been widely reported in lateral flow biosensors, offering new sensing strategies based on optical or electrical detection techniques. Looking for other advantageous nanomaterials, we propose for the first time the use of iridium oxide (IV) nanoparticles in lateral flow assays for the detection of human immunoglobulin as a model protein. These nanoparticles can be easily prepared and conjugated with biomarkers. Their dark blue color gives a high contrast against the white background of the strips being in this way excellent labels

Integrated biocatalytic platform based on aqueous biphasic systems for the sustainable oligomerization of rutin

Rutin is a known antioxidant compound that displays a broad range of biological activities and health-related benefits but presents a low water solubility that can be overcome by its polymerization. In this work, biocompatible aqueous biphasic systems composed of the ionic liquid cholinium dihydrogen phosphate ([CH][DHph]) and the polymer poly(ethylene glycol) 600 (PEG 600) were investigated as an efficient integrated reaction–separation platform for the laccase-catalyzed oligomerization of rutin. Two different approaches were studied to reuse laccase in several oligorutin production cycles, the main difference between them being the use of monophasic or biphasic regimes during the oligomerization reaction. The use of a biphasic regime in the second approach (heterogeneous reaction medium) allowed the successful reuse of the biocatalyst in three consecutive reaction–separation cycles while achieving noteworthy rutin oligomerization yields (95% in the first cycle, 91% in the second cycle, and 89% in the last cycle). These remarkable results were caused by the combination of the increased solubility of rutin in the PEG-rich phase together with the enhanced catalytic performance of laccase in the [Ch][DHph]-rich phase, alongside with the optimization of the pH of the reaction medium straightly linked to enzyme stability. Finally, a life-cycle assessment was performed to compare this integrated reaction–separation platform to three alternative processes, reinforcing its sustainabilityThis research was supported by the Spanish Government (AEI) through the RTI2018-094482-J-I00 project. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. The programme is cofunded by FEDER (UE). A.P.M.T. thanks the FCT for the research contract CEECIND/2020/01867. G.E. thanks the Spanish MICIU for her Ramón y Cajal contract (RYC2018- 024846-I). A.M.-M. thanks the Programa de axudas á etapa predoutoral da Xunta de Galicia (ED481A-2018/023)S

DD04107-Derived neuronal exocytosis inhibitor peptides: Evidences for synaptotagmin-1 as a putative target

The analgesic peptide DD04107 (Pal-EEMQRR-NH2) and its acetylated analogue inhibit a-calcitonin gene-related peptide (a-CGRP) exocytotic release from primary sensory neurons. Examining the crystal structure of the SNARE-Synaptotagmin-1(Syt1) complex, we hypothesized that these peptides could inhibit neuronal exocytosis by binding to Syt1, hampering at least partially its interaction with the SNARE complex. To address this hypothesis, we first interrogate the role of individual side-chains on the inhibition of a-CGRP release, finding that E1, M3, Q4 and R6 residues were crucial for activity. CD and NMR conformational analysis showed that linear peptides have tendency to adopt a-helical conformations, but the results with cyclic analogues indicated that this secondary structure is not needed for activity. Isothermal titration calorimetry (ITC) measurements demonstrate a direct interaction of some of these peptides with Syt1-C2B domain, but not with Syt7-C2B region, indicating selectivity. As expected for a compound able to inhibit a-CGRP release, cyclic peptide derivative Pal-E-cyclo[EMQK]R-NH2 showed potent in vivo analgesic activity, in a model of inflammatory pain. Molecular dynamics simulations provided a model consistent with KD values for the interaction of peptides with Syt1-C2B domain, and with their biological activity. Altogether, these results identify Syt1 as a potential new analgesic target. © 202

Effectiveness of Protein Supplementation Combined with Resistance Training on Muscle Strength and Physical Performance in Elderly: A Systematic Review and Meta-Analysis

The aim of this study was to evaluate the effectiveness of the combination of resistance training (RT) and protein supplementation (PS), compared to RT alone or combined with a placebo (plS), in the improvement of muscle strength and physical performance. The search strategy in PubMed, Cochrane Library, and Web of Sciences databases found a total of 294 studies. Once inclusion and exclusion criteria were applied, 16 studies were included for the qualitative analysis. A total of 657 healthy elderly (>60 years) participants were analysed. Finally, 15 articles were included in the quantitative analysis with one being excluded due to issues with data availability. Upper-limb, lower-limb, and handgrip strength were the primary outcomes of the meta-analysis. The secondary outcomes, related to physical performance, were Short Physical Performance Battery (SPPB), gait speed, and the five-chair-rise test (5CRT). The main results of the meta-analysis show no statistical differences for upper-limb (SMD: 0.56, 95% CI: -0.09, 1.21, p = 0.09, I2 = 68%), lower-limb (SMD: 0.00, 95% CI: -0.18, 0.18, p = 1.0, I2 = 11%), and handgrip strength (SMD: 0.03, 95% CI: -0.26, 0.32, p = 0.84, I2 = 0%) between the RT + PS and the RT alone (or combined with plS). Moreover, no statistical differences were found relating to physical performance. In view of these results, protein supplementation combined with RT does not provide additional benefits compared to RT alone or with plS in healthy elderly adults

Resumen de la tarea Rest-Mex en IberLEF 2023: Investigaci´on sobre An´alisis de Sentimiento para Textos Tur´ısticos Mexicanos

This paper presents the framework and results of the Rest-Mex task at IberLEF 2023, focusing on sentiment analysis and text clustering of tourist texts. The study primarily focuses on texts related to tourist destinations in Mexico, although this edition included data from Cuba and Colombia for the first time. The sentiment analysis task aims to predict the polarity of opinions expressed by tourists, classifying the type of place visited, whether it’s a tourist attraction, hotel, or restaurant, as well as the country it is located in. On the other hand, the text clustering task aims to classify news articles related to tourism in Mexico. For both tasks, corpora were built using Spanish opinions extracted from TripAdvisor and news articles from Mexican media. This article compares and discusses the results obtained by the participants in both sub-tasks. Additionally, a method is proposed to measure the easiness of a multi-class text classification corpus, along with an approach for system selection in a possible late fusion scheme.Este artículo presenta el marco y los resultados de la tarea Rest-Mex en IberLEF 2023, que se enfoca en el análisis de sentimiento y agrupamiento de textos turísticos. El estudio se centra principalmente en textos relacionados con destinos turísticos en México, aunque esta edición incluyó datos de Cuba y Colombia por primera vez. La tarea de análisis de sentimiento tiene como objetivo predecir la polaridad de opiniones expresadas por turistas, clasificando el tipo de lugar visitado, ya sea un atractivo turístico, un hotel o un restaurante, así como el país en el que se encuentra. Por otro lado, la tarea de agrupamiento de textos busca clasificar noticias relacionadas con el turismo en México. Para ambas tareas, se construyeron corpus utilizando opiniones en español extraídas de TripAdvisor y noticias de medios mexicanos. En este artículo, se comparan y discuten los resultados obtenidos por los participantes en ambas sub tareas. Además, se propone un método para medir la facilidad de un corpus de clasificación textual multi-clase, así como un enfoque para la selección de sistemas en un posible esquema de fusión tardía.The authors thank the Mexican Academy of Tourism Research (AMIT) for their support of the project ”Creation of a labeled database related to tourist destinations for training artificial intelligence models for classifying relevant topics” through the call ”I Research Projects 2022”, which originated this work

Coral Reef Resilience Index for Novel Ecosystems: A Spatial Planning Tool for Managers and Decision Makers - A Case Study from Puerto Rico

Timely information is critical for coral reef managers and decision-makers to implement sustainable management measures. A Coral Reef Resilience Index (CRRI) was developed with a GIS-coupled decision-making tool applicable for Caribbean coral reef ecosystems. The CRRI is based on a five-point scale parameterized from the quantitative characterization of benthic assemblages. Separate subindices such as the Coral Index, the Threatened Species Index, and the Algal Index also provide specific information regarding targeted benthic components. This case study was based on assessments conducted in 2014 on 11 reef sites located across 3 geographic zones and 3 depth zones along the southwestern shelf of the island of Puerto Rico, Caribbean Sea. There was a significant spatial and bathymetric gradient (p < 0.05) in the distribution of CRRI values indicating higher degradation of inshore reefs. Mean global CRRI ranged from 2.78 to 3.17 across the shelf, ranking them as “fair.” The Coral Index ranged from 2.60 to 3.76, ranking reefs from “poor” to “good,” showing a general cross-shelf trend of improving conditions with increasing distance from pollution sources. Turbidity and ammonia were significantly correlated to CRRI scores. Multiple recommendations are provided based on coral reef conditions according to observed CRRI rankings