Short peptide and amino acid-based supramolecular ionogels and eutectogels.

The capability of peptide and amino acid-based molecules to act as ionogelators and eutectogelators entrapping ionic liquids (ILs) and deep eutectic solvents (DESs) forming ionogels and eutectogels has gathered attention in recent decades. The self-assembly process, primarily driven by non-covalent interactions as hydrogen bonding, remains serendipitous in nature.  This review provides a comprehensive and detailed report on self-assembly of unmodified and modified amino acids and peptides in the non-conventional solvents, ILs and DESs. Understanding these processes holds great promise for the development of innovative soft-materials, and to the progress of supramolecular systems in non-conventional solvent environments.

Bacteria: Potential Make-or-Break Determinants of Celiac Disease.

Celiac disease is an autoimmune disease triggered by dietary gluten in genetically susceptible individuals that primarily affects the small intestinal mucosa. The sole treatment is a gluten-free diet that places a social and economic burden on patients and fails, in some, to lead to symptomatic or mucosal healing. Thus, an alternative treatment has long been sought after. Clinical studies on celiac disease have shown an association between the presence of certain microbes and disease outcomes. However, the mechanisms that underlie the effects of microbes in celiac disease remain unclear. Recent studies have employed disease models that have provided insights into disease mechanisms possibly mediated by bacteria in celiac disease. Here, we have reviewed the bacteria and related mechanisms identified so far that might protect from or incite the development of celiac disease. Evidence indicates bacteria play a role in celiac disease and it is worth continuing to explore this, particularly since few studies, to the best of our knowledge, have focused on establishing a mechanistic link between bacteria and celiac disease. Uncovering host-microbe interactions and their influence on host responses to gluten may enable the discovery of pathogenic targets and development of new therapeutic or preventive approaches.

Pain management in zebrafish : Report from a FELASA Working Group.

Empirical evidence suggests fishes meet the criteria for experiencing pain beyond a reasonable doubt and zebrafish are being increasingly used in studies of pain and nociception. Zebrafish are adopted across a wide range of experimental fields and their use is growing particularly in biomedical studies. Many laboratory procedures in zebrafish involve tissue damage and this may give rise to pain. Therefore, this FELASA Working Group reviewed the evidence for pain in zebrafish, the indicators used to assess pain and the impact of a range of drugs with pain-relieving properties. We report that there are several behavioural indicators that can be used to determine pain, including reduced activity, space use and distance travelled. Pain-relieving drugs prevent these responses, and we highlight the dose and administration route. To minimise or avoid pain, several refinements are suggested for common laboratory procedures. Finally, practical suggestions are made for the management and alleviation of pain in laboratory zebrafish, including recommendations for analgesia. Pain management is an important refinement in experimental animal use and so our report has the potential to improve zebrafish welfare during and after invasive procedures in laboratories across the globe.

Impact of the Cationic Moiety of Ionic Liquids on Chemoselective Artificial Olfaction.

Ionogels and derived materials are assemblies of polymers and ionic liquids characterized by high stability and ionic conductivity, making them interesting choices as gas sensors. In this work, we assessed the effect of the ionic liquid moiety to generate ionogels and hybrid gels as electrical and optical gas sensors. Six ionic liquids consisting of a constant anion (chloride) and distinct cationic head groups were used to generate ionogels and hybrid gels and further tested as gas sensors in customized electronic nose devices. In general, ionogel-based sensors yielded higher classification accuracies of standard volatile organic compounds when compared to hybrid material-based sensors. In addition, the high chemical diversity of ionic liquids is further translated to a high functional diversity in analyte molecular recognition and sensing.

Hierarchical self-assembly of a reflectin-derived peptide.

Reflectins are a family of intrinsically disordered proteins involved in cephalopod camouflage, making them an interesting source for bioinspired optical materials. Understanding reflectin assembly into higher-order structures by standard biophysical methods enables the rational design of new materials, but it is difficult due to their low solubility. To address this challenge, we aim to understand the molecular self-assembly mechanism of reflectin's basic unit-the protopeptide sequence YMDMSGYQ-as a means to understand reflectin's assembly phenomena. Protopeptide self-assembly was triggered by different environmental cues, yielding supramolecular hydrogels, and characterized by experimental and theoretical methods. Protopeptide films were also prepared to assess optical properties. Our results support the hypothesis for the protopeptide aggregation model at an atomistic level, led by hydrophilic and hydrophobic interactions mediated by tyrosine residues. Protopeptide-derived films were optically active, presenting diffuse reflectance in the visible region of the light spectrum. Hence, these results contribute to a better understanding of the protopeptide structural assembly, crucial for the design of peptide- and reflectin-based functional materials.

Vibrio eleionomae sp. nov., isolated from shrimp (Penaeus vannamei) pond water.

A novel Vibrio strain (CAIM 722T=SW9T=DSM 24596T) was isolated in 2003 from water of a shrimp (Penaeus vannamei) culture pond located in Los Mochis, Sinaloa, Mexico, and taxonomically characterized using a polyphasic approach. The 16S rRNA gene sequence clustered within those of the genus Vibrio, showing high similarity to the type strains of the Porteresiae clade. Multilocus sequence analysis using eight housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA, topA and 16S rRNA) and phylogenetic analysis with 139 single-copy genes showed that the strain forms an independent branch. Whole genome sequencing and genomic analyses (average nucleotide identity, OrthoANI, average amino acid identity and in silico DNA-DNA hybridization) produced values well below the thresholds for species delineation with all methods tested. In addition, a phenotypic characterization was performed to support the description and differentiation of the novel strain from related taxa. The results obtained demonstrate that the strain represent a novel species, for which the name Vibrio eleionomae sp. nov. is proposed.

Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses.

Relative humidity (RH) is a common interferent in chemical gas sensors, influencing their baselines and sensitivity, which can limit the performance of e-nose systems. Tuning the composition of the sensing materials is a possible strategy to control the impact of RH in gas sensors. Hybrid gel materials used as gas sensors contain self-assembled droplets of ionic liquid and liquid crystal molecules encapsulated in a polymeric matrix. In this work, we assessed the effect of the matrix hydrophobic properties in the performance of hybrid gel materials for VOC sensing in humid conditions (50% RH). We used two different polymers, the hydrophobic PDMS and the hydrophilic bovine gelatin, as polymeric matrices in hybrid gel materials containing imidazolium-based ionic liquids, [BMIM][Cl] and [BMIM][DCA], and the thermotropic liquid crystal 5CB. Better accuracy of VOC prediction is obtained for the hybrid gels composed of a PDMS matrix combined with the [BMIM][Cl] ionic liquid, and the use of this hydrophobic matrix reduces the effect of humidity on the sensing performance when compared to the gelatin counterpart. VOCs interact with all the moieties of the hybrid gel multicomponent system; thus, VOC correct classification depends not only on the polymeric matrix used, but also on the IL selected, which seems to be key to achieve VOCs discrimination at 50% RH. Thus, hybrid gels' tunable formulation offers the potential for designing complementary sensors for e-nose systems operable under different RH conditions.

Emergence and clonal expansion of Vibrio aestuarianus lineages pathogenic for oysters in Europe.

Crassostrea gigas oysters represent a significant global food source with 4.7 million tons harvested per year. In 2001, the bacterium Vibrio aestuarianus subsp. francensis emerged as a pathogen that causes adult oyster mortality in France and Ireland. Its impact on oyster aquaculture has increased in Europe since its re-emergence in 2012. To better understand the evolutionary mechanisms leading to the emergence and persistence over time of this pathogen, we conducted a survey of mollusc diseases through national reference laboratories across Europe. We analysed 54 new genomes of Vibrio aestuarianus (Va) isolated from multiple environmental compartments since 2001, in areas with and without bivalve mortalities. We used a combination of comparative genomics and population genetics approaches and show that Va has a classical epidemic population structure from which the pathogenic Va francensis subspecies emerged and clonally expanded. Furthermore, we identified a specific cus-cop-containing island conferring copper resistance to Va francensis whose acquisition may have favoured the emergence of pathogenic lineages adapted and specialized to oysters.

Affective Relationships Among Siblings in a Situation of Institutional Care / Relações Afetivas entre Irmãos em Situação de Acolhimento Institucional

Abstract The purpose of this article is to identify the relationships of affection that exist between children/adolescents institutionalized in the same shelter. Data collection was carried out in two sisters hosted in Brasília-DF, through field notes, documentary analysis script, theme-story drawing, collage and semi-structured interviews. The indicators arouse from the results, which guided the organization of two of the sense zones, based on the methodology developed by Gonzalez Rey: a) The family of origin and the affective memories; b) Institutionalization and affection in the fraternal relationship. The importance of the sibling group was identified for the establishment of the sense of security, protection and pre-disposition for more positive and resilient attitudes.

Resumo O objetivo deste artigo é compreender as relações de afeto preservadas pelos irmãos crianças/adolescentes institucionalizados numa mesma instituição. A coleta de dados foi realizada em duas irmãs acolhidas em Brasília-DF, por meio do diário de campo, roteiro de análise documental, desenho-história com tema, colagem e entrevistas semiestruturadas. A partir dos resultados foram levantados os indicadores que orientaram a organização de duas das zonas de sentidos, baseada na metodologia desenvolvida por Gonzalez Rey: a) Memórias afetivas sobre a família de origem; b) Institucionalização e afeto na relação fraterna. Identificou-se a importância do grupo de irmãos para o estabelecimento do sentimento de segurança, proteção e pré-disposição para atitudes mais positivas e resilientes.

Solvent modulation in peptide sub-microfibers obtained by solution blow spinning.

Peptides possess high chemical diversity at the amino acid sequence level, which further translates into versatile functions. Peptides with self-assembling properties can be processed into diverse formats giving rise to bio-based materials. Peptide-based spun fibers are an interesting format due to high surface-area and versatility, though the field is still in its infancy due to the challenges in applying the synthetic polymer spinning processes to protein fibers to peptides. In this work we show the use of solution blow-spinning to produce peptide fibers. Peptide fiber formation was assisted by the polymer poly (vinyl pyrrolidone) (PVP) in two solvent conditions. Peptide miscibility and further self-assembling propensity in the solvents played a major role in fiber formation. When employing acetic acid as solvent, peptide fibers (0.5 µm) are formed around PVP fibers (0.75 µm), whereas in isopropanol only one type of fibers are formed, consisting of mixed peptide and PVP (1 µm). This report highlights solvent modulation as a mean to obtain different peptide sub-microfibers via a single injection nozzle in solution blow spinning. We anticipate this strategy to be applied to other small peptides with self-assembly propensity to obtain multi-functional proteinaceous fibers.

Vibrio pathogenicity island and phage CTX genes in Vibrio alginolyticus isolated from different aquatic environments.

In the present study, we investigated the presence of four Vibrio cholerae virulence genes (ctxA, VPI, Zot and ace) in 36 Vibrio alginolyticus isolates obtained from different seawater, sediments and aquatic organisms. We tested the virulence of 13 V. alginolyticus strains against juveniles of Sparus aurata and this virulence was correlated with the presence of V. cholerae virulence genes. A positive amplification for the virulence pathogenicity island was produced by five V. alginolyticus strains and four for cholerae toxin. Some of the V. alginolyticus strains are pathogenic to aquatic animals and might have derived their virulence genes from V. cholerae. V. alginolyticus strains can be considered as a possible reservoir of V. cholerae virulence genes.

Synergy between silk fibroin and ionic liquids for active gas-sensing materials.

Silk fibroin is a biobased material with excellent biocompatibility and mechanical properties, but its use in bioelectronics is hampered by the difficult dissolution and low intrinsic conductivity. Some ionic liquids are known to dissolve fibroin but removed after fibroin processing. However, ionic liquids and fibroin can cooperatively give rise to functional materials, and there are untapped opportunities in this combination. The dissolution of fibroin, followed by gelation, in designer ionic liquids from the imidazolium chloride family with varied alkyl chain lengths (2-10 carbons) is shown here. The alkyl chain length of the anion has a large impact on fibroin secondary structure which adopts unconventional arrangements, yielding robust gels with distinct hierarchical organization. Furthermore, and due to their remarkable air-stability and ionic conductivity, fibroin ionogels are exploited as active electrical gas sensors in an electronic nose revealing the unravelled possibilities of fibroin in soft and flexible electronics.

Native, engineered and de novo designed ligands targeting the SARS-CoV-2 spike protein.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the deadly coronavirus disease 2019 (Covid-19) and is a concerning hazard to public health. This virus infects cells by establishing a contact between its spike protein (S-protein) and host human angiotensin-converting enzyme 2 (hACE2) receptor, subsequently initiating viral fusion. The inhibition of the interaction between the S-protein and hACE2 has immediately drawn attention amongst the scientific community, and the S-protein was considered the prime target to design vaccines and to develop affinity ligands for diagnostics and therapy. Several S-protein binders have been reported at a fast pace, ranging from antibodies isolated from immunised patients to de novo designed ligands, with some binders already yielding promising in vivo results in protecting against SARS-CoV-2. Natural, engineered and designed affinity ligands targeting the S-protein are herein summarised, focusing on molecular recognition aspects, whilst identifying preferred hot spots for ligand binding. This review serves as inspiration for the improvement of already existing ligands or for the design of new affinity ligands towards SARS-CoV-2 proteins. Lessons learnt from the Covid-19 pandemic are also important to consolidate tools and processes in protein engineering to enable the fast discovery, production and delivery of diagnostic, prophylactic, and therapeutic solutions in future pandemics.

Nanoscale Events on Cyanobiphenyl-Based Self-Assembled Droplets Triggered by Gas Analytes.

Liquid crystals (LCs) are prime examples of dynamic supramolecular soft materials. Their autonomous self-assembly at the nanoscale level and the further nanoscale events that give rise to unique stimuli-responsive properties have been exploited for sensing purposes. One of the key features to employ LCs as sensing materials derives from the fine-tuning between stability and dynamics. This challenging task was addressed in this work by studying the effect of the alkyl chain length of cyanobiphenyl LCs on the molecular self-assembled compartments organized in the presence of ionic liquid molecules and gelatin. The resulting multicompartment nematic and smectic gels were further used as volatile organic compound chemical sensors. The LC structures undergo a dynamic sequence of phase transitions, depending on the nature of the LC component, yielding a variety of optical signals, which serve as optical fingerprints. In particular, the materials incorporating smectic compartments resulted in unexpected and rich optical textures that have not been reported previously. Their sensing capability was tested in an in-house-assembled electronic nose and further assessed via signal collection and machine-learning algorithms based on support vector machines, which classified 12 different gas analytes with high accuracy scores. Our work expands the knowledge on controlling LC self-assembly to yield fast and autonomous accurate chemical-sensing systems based on the combination of complex nanoscale sensing events with artificial intelligence tools.

Frailty influences the vascular responsiveness of elderly individuals with chronic heart failure.

INTRODUCTION: Frailty is highly prevalent in heart failure (HF) patients. HF is associated with oxidative stress and chronic inflammation, which impair oxygen use by skeletal muscles. Little is known about the influence of frailty on vascular responsiveness and tissue oxygenation. OBJECTIVE: Analyze the influence of frailty on vascular responsiveness and muscle oxygenation in elderly individuals with and without HF. METHODS: Individuals aged ≥60 years, with or without HF, were evaluated for frailty (phenotype). Near-infrared spectroscopy (NIRS) was used to assess muscle oxygenation at rest (oxygen saturation - StO2 and deoxyhemoglobin) and during handgrip exercise (minimum StO2 and maximum deoxyhemoglobin), and oxygenation variables. STATISTICAL ANALYSIS: Results were grouped according to the frailty phenotype: non-frail, pre-frail, and frail. Shapiro-Wilk test was used to assess normality. Data were compared using a two-way analysis of variance (ANOVA). Bonferroni post hoc test was applied to determine the influence of frailty or HF on NIRS variables. SPSS software was used in the analyses; p < 0.05 was considered significant. RESULTS: 55 elderly participants (61.8% female; 70.4 ± 7.2 years old; 28 HF patients) participated in the study. 32.7% (n = 18) were classified as non-frail, 43.3% (n = 24) as pre-frail, and 23.6% (n = 13) as frail. The analysis of vascular responsiveness (n = 52) identified an influence (p < 0.05) of frailty on the reperfusion rate (slope 2 and ∆StO2 of nadir-peak) and desaturation during occlusion (area under the curve of StO2) in HF patients. There was no influence of frailty or HF on muscle oxygenation at rest and during exercise (n = 54; p > 0.05). CONCLUSION: The coexistence of frailty and HF seems to impair vascular responsiveness, as frail elderly participants with HF presented lower reperfusion rates and higher desaturation levels during the arterial occlusion test. However, the presence of frailty or HF alone had no influence on muscle oxygenation at rest or during exercise.

O desempenho e as respostas fisiológicas ao teste de elevação do calcanhar bipodal são influenciados pela cadência e posição dos tornozelos / Bilateral heel-rise test performance and physiological response are influenced by cadence and ankle position

INTRODUÇÃO: Diferentes protocolos do teste de elevação do calcanhar (TEC) têm sido utilizados, sendo necessário analisar o impacto das variações nas respostas do teste. OBJETIVO: Comparar o desempenho e respostas de oxigenação muscular (OM) e frequência cardíaca (FC) de adultos em diferentes protocolos do TEC bipodal. MATERIAIS E MÉTODOS: Este foi um estudo transversal do tipo cruzado. Trinta participantes (23,1±2,9 anos; 16 homens) realizaram quatro protocolos do TEC bipodal, variando cadenciamento (autocadenciado e cadenciado externamente) e posição dos tornozelos (neutra e dorsiflexão). Para a OM, analisamos a saturação tecidual de oxigênio (StO2 ) e variação da concentração de oxihemoglobina (∆[O2 Hb]) e calculamos a variação entre os menores valores e os valores finais (∆Nadir-Final) e área sob a curva (AUC). Para a FC, calculamos a variação dos valores iniciais e finais (∆FC) e constante de tempo (τ). O teste de Friedman foi utilizado para comparar as variáveis entre os protocolos. A ANOVA de dois fatores foi utilizada para identificar o impacto da cadência e/ou posição dos tornozelos. RESULTADOS: O número de repetições e o tempo de execução foram maiores nos protocolos em posição neutra e cadenciado externamente (p<0,001 para ambos). ∆Nadir-Final (StO2: p<0,001; ∆[O2Hb]: p=0,005) e AUC (StO2: p<0,001; ∆[O2Hb]: p<0,001) dea mbas as variáveis de OM foram maiores nos protocolos em posição neutra. Protocolos autocadenciados apresentaram maior aumento da FC e τ mais rápida (p=0,006 e p=0,046). CONCLUSÃO: O TEC realizado em posição neutra e cadenciamento externo gera maiores repetições e tempo de execução. A dorsiflexão promoveu menor reperfusão muscular e o autocadenciamento, maior e mais rápido aumento da FC.

INTRODUCTION: Different heel-rise test (HRT) protocols have been used, possibly leading to varied responses. It is necessary to analyse the impact of protocol variation on test responses. PURPOSE: To compare the performance, muscle oxygenation (MO), and heart rate (HR) responses of adults in bilateral HRT protocols. METHODS: This was a cross-sectional crossover study. Thirty participants (23.1±2.9 years; 16 men) performed four bilateral HRT protocols with varying cadence (self-cadenced; externally cadenced) and ankle position (neutral; dorsiflexion). For MO responses, we analysed tissue oxygen saturation (StO2) and oxyhemoglobin concentration variation (∆[O2Hb]) and calculated the variation between the smallest and final values (∆Nadir-Final) and the area under the curve (AUC). The variation between the initial and final HR values (∆HR) and the time constant (τ) were calculated. Friedman's test was used to compare the variables among the protocols. Two-way ANOVA was used to identify the impact of cadence and/or ankle position. RESULTS: The number of repetitions and execution time were higher in the neutral position and externally cadenced protocols (p<0.001 for both). ∆Nadir-Final (StO2: p<0.001;∆[O2Hb]: p=0.005) and AUC (StO2: p<0.001; ∆[O2Hb]: p<0.001) of both MO variables were higher in the neutral position protocols. Selfcadenced protocols presented higher HR increase and faster τ (p=0.006 and p=0.046). CONCLUSION: Bilateral HRT performed in a neutral position, and external cadence promotes more repetitions and a longer execution time. Dorsiflexion promotes lower muscle reperfusion, and self-cadence higher and faster HR increase.

Tackling Humidity with Designer Ionic Liquid-Based Gas Sensing Soft Materials.

Relative humidity is simultaneously a sensing target and a contaminant in gas and volatile organic compound (VOC) sensing systems, where strategies to control humidity interference are required. An unmet challenge is the creation of gas-sensitive materials where the response to humidity is controlled by the material itself. Here, humidity effects are controlled through the design of gelatin formulations in ionic liquids without and with liquid crystals as electrical and optical sensors, respectively. In this design, the anions [DCA]- and [Cl]- of room temperature ionic liquids from the 1-butyl-3-methylimidazolium family tailor the response to humidity and, subsequently, sensing of VOCs in dry and humid conditions. Due to the combined effect of the materials formulations and sensing mechanisms, changing the anion from [DCA]- to the much more hygroscopic [Cl]- , leads to stronger electrical responses and much weaker optical responses to humidity. Thus, either humidity sensors or humidity-tolerant VOC sensors that do not require sample preconditioning or signal processing to correct humidity impact are obtained. With the wide spread of 3D- and 4D-printing and intelligent devices, the monitoring and tuning of humidity in sustainable biobased materials offers excellent opportunities in e-nose sensing arrays and wearable devices compatible with operation at room conditions.

Stable and Oriented Liquid Crystal Droplets Stabilized by Imidazolium Ionic Liquids.

Liquid crystals represent a fascinating intermediate state of matter, with dynamic yet organized molecular features and untapped opportunities in sensing. Several works report the use of liquid crystal droplets formed by microfluidics and stabilized by surfactants such as sodium dodecyl sulfate (SDS). In this work, we explore, for the first time, the potential of surface-active ionic liquids of the imidazolium family as surfactants to generate in high yield, stable and oriented liquid crystal droplets. Our results show that [C12MIM][Cl], in particular, yields stable, uniform and monodisperse droplets (diameter 74 ± 6 µm; PDI = 8%) with the liquid crystal in a radial configuration, even when compared with the standard SDS surfactant. These findings reveal an additional application for ionic liquids in the field of soft matter.