Antilisterial and physical properties of biopolymer films containing lactic acid bacteria

Novel biopolymer films were developed and used to control Listeria innocua in an artificially contaminated synthetized medium. Two hydrocolloids, sodium caseinate (NaCas) and methylcellulose (MC), and two bacteriocin-producing lactic acid bacteria (LAB), Lactobacillus acidophilus and Lactobacillus reuteri, were tested. Bioactive cultures were added directly to the film forming solution and films were obtained by casting. In order to study the impact of the incorporation of bacterial cells into the biopolymer matrix, the water vapour permeability, optical and mechanical properties of the dry films were evaluated. Furthermore, the survival of LAB and the antimicrobial potential of bioactive films against L. innocua were studied. Results showed that the use of lactic acid bacteria altered the film s physical properties. Films enriched with bacterial cells exhibit higher gloss and transparency whereas no significant modifications were observed in terms of tensile properties. These films were less-effective water vapour barriers, since a significant increase can be observed in the WVP values. As far as food safety is concerned, these films are an interesting, novel approach. In refrigeration conditions, these films permit a complete inhibition of L. innocua for a week. Viability of LAB was higher in sodium caseinate films, although bacteriocin production was greater in polysaccharide matrix. The best results were obtained for films made of methylcellulose, without differences between the two lactic acid bacteria tested.The authors acknowledge the financial support from Spanish Ministerio de Educacion y Ciencia throughout the project AGL201020694. Author L. Sgnchez-Gonzalez thanks the support of Campus de Excelencia Internacional from Universidad Politecnica de Valencia.Sanchez-Gonzalez, L.; Quintero Saavedra, JI.; Chiralt, A. (2014). Antilisterial and physical properties of biopolymer films containing lactic acid bacteria. Food Control. 35(1):200-206. https://doi.org/10.1016/j.foodcont.2013.07.001S20020635

Corrosion fatigue initiation in stainless steels : The scanning reference electrode technique.

The early stages of damage by corrosion fatigue in austenitic and duplex stainless steel were studied using a novel scanning reference electrode technique (SRET). Emphasis was made on the role played by corrosion pits, which can act as stress concentrators and promote fatigue crack nucleation. SRET measurements conducted during the potentiostatic generation of pits on the austenitic stainless steels in artificial seawater showed that the pit current density increases with the time of application of anodic polarisation. The data of the volume of metal dissolved calculated from pit current density obtained by SRET agreed well with the measurements of pit profiles. The austenitic and duplex stainless steels showed high resistance to pitting corrosion in artificial seawater at free corrosion potential. The use of a 0.05 M FeCl3 solution as the electrolyte promoted severe localised attack in 304 and 316L stainless steel specimens. SRET tests carried out simultaneously with the application of cyclic stress to the specimens permitted the evolution of the electrochemical activity of corrosion pits to be followed. Transformation from pitting to fatigue cracking was observed. In this work it is proposed that a decrease of the pit electrochemical activity in terms of pit current density, is related to the nucleation of the corrosion fatigue crack. From SRET measurements a critical pit depth was calculated for the nucleation of the fatigue crack. A threshold stress intensity factor range was then calculated, which was found to be similar to the values reported in the literature.It is suggested at the end of this thesis that parallel studies and measurements of the pit-to-crack transition can be conducted in order to corroborate the reliability of SRET measurements to assess semi-quantitatively the threshold conditions for the transition. The scanning reference electrode technique showed advantages over other electrochemical methods used to assess the damage induced by localised corrosion in that it provides in-situ, spatially resolved, real-time electrochemical activity measurements

Correlation between the Altered Gut Microbiome and Lifestyle Interventions in Chronic Widespread Pain Patients: A Systematic Review

: Background: Lifestyle interventions have a direct impact on the gut microbiome, changing its composition and functioning. This opens an innovative way for new therapeutic opportunities for chronic widespread patients. Purpose: The goal of the present study was to evaluate a correlation between lifestyle interventions and the gut microbiome in patients with chronic widespread pain (CWP). Methods: The systematic review was conducted until January 2023. Pain and microbiome were the two keywords selected for this revision. The search was conducted in PubMed, Chochrane, PEDro and ScienceDirect, where 3917 papers were obtained. Clinical trials with lifestyle intervention in CWP patients were selected. Furthermore, these papers had to be related with the gut microbiome, excluding articles related to other types of microbiomes. Results: Only six articles were selected under the eligibility criteria. Lifestyle interventions were exercise, electroacupuncture and ingesting a probiotic. Conclusions: Lifestyle intervention could be a suitable choice to improve the gut microbiome. This fact could be extrapolated into a better quality of life and lesser levels of pain

Validity of a self-reported diagnosis of depression among participants in a cohort study using the Structured Clinical Interview for DSM-IV (SCID-I).

Abstract Background: Depression assessment in population studies is usually based on depressive symptoms scales. However, the use of scales could lead to the choice of an arbitrary cut-off point depending on the sample characteristics and on the patient diagnosis. Thus, the use of a medical diagnosis of depression could be a more appropriate approach. Objective: To validate a self-reported physician diagnosis of depression using the Structured Clinical Interview for DSM-IV (SCID-I) as Gold Standard and to assess the factors associated to a valid self-reported diagnosis. Methods: The SUN Project is a cohort study based on university graduates followed-up through postal questionnaires. The response to the question included in the questionnaire: Have you ever been diagnosed of depression by a physician? was compared to that obtained through the SCID-I applied by a psychiatrist or a clinical psychologist. The percentages of confirmed depression and non-depression were assessed for the overall sample and according to several characteristics. Logistic regression models were fitted to ascertain the association between different factors and a correct classification regarding depression status. Results: The percentage of confirmed depression was 74.2%; 95% confidence interval (95% CI) =63.3-85.1. Out of 42 participants who did not report a depression diagnosis in the questionnaire, 34 were free of the disease (%confirmed non-depression=81.1%; 95% CI=69.1- 92.9). The probability of being a true positive was higher among ex- smokers and non-smokers and among those overweight or obese but the differences were not statistically significant. Conclusion: The validity of a self-reported diagnosis of depression in the SUN cohort is adequate. Thus, this question about depression diagnosis could be used in further investigations regarding this disease in this graduate cohort study

Conocimiento científico y medios de comunicación: desafíos del periodismo científico en Colombia

La noticia debe informar al lector y permitirle construir una opinión sobre el tema leído, sin embargo, los medios de comunicación colombianos no reflejan adecuadamente el papel preponderante que algunas secciones deben tener, debido a la preferencia de los medios de comunicación por noticias blandas y sin mucho contenido. El periodismo científico colombiano atraviesa dos problemas: la falta de especialización de los periodistas y el poco apoyo de los investigadores, sin embargo, en los últimos años se ha incrementado la capacitación de los comunicadores en esta área, cuyo trabajo consiste en convertir el resultado de la investigación a un lenguaje más sencillo para que así sea entendido con mayor facilidad por las audiencias. El objetivo de este artículo de reflexión es describir algunas deficiencias y desafíos que presenta el periodismo científico en Colombia

Stellar Population gradients in galaxy discs from the CALIFA survey

While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at $\sim$2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&

Human adaptations to multiday saturation on NASA NEEMO

Human adaptation to extreme environments has been explored for over a century to understand human psychology, integrated physiology, comparative pathologies, and exploratory potential. It has been demonstrated that these environments can provide multiple external stimuli and stressors, which are sufficient to disrupt internal homeostasis and induce adaptation processes. Multiday hyperbaric and/or saturated (HBS) environments represent the most understudied of environmental extremes due to inherent experimental, analytical, technical, temporal, and safety limitations. National Aeronautic Space Agency (NASA) Extreme Environment Mission Operation (NEEMO) is a space-flight analog mission conducted within Florida International University's Aquarius Undersea Research Laboratory (AURL), the only existing operational and habitable undersea saturated environment. To investigate human objective and subjective adaptations to multiday HBS, we evaluated aquanauts living at saturation for 9-10 days via NASA NEEMO 22 and 23, across psychologic, cardiac, respiratory, autonomic, thermic, hemodynamic, sleep, and body composition parameters. We found that aquanauts exposed to saturation over 9-10 days experienced intrapersonal physical and mental burden, sustained good mood and work satisfaction, decreased heart and respiratory rates, increased parasympathetic and reduced sympathetic modulation, lower cerebral blood flow velocity, intact cerebral autoregulation and maintenance of baroreflex functionality, as well as losses in systemic bodyweight and adipose tissue. Together, these findings illustrate novel insights into human adaptation across multiple body systems in response to multiday hyperbaric saturation

Mechanical Biosensors in Biological and Food Area: a Review

A review of state the art about the structure, classification and operation of biosensors applied in food and biological areas is presented. This review is focused to mechanical biosensors that use mill, micro and nanocantilevers. Basic concepts of atomic force microscopy and optical systems, used as testing platform of biosensors are described. The most funcionalized strategies and geometrical configurations are also explained. Mathematical methods for evaluating the performance in static and dynamic mode of the mechanical biosensors are reviewed and examples of application in biological and food areas are provided. An overall description of the operational effect of operation conditions and design variables on the sensitivity devices is also proposed. A brief description of the design processes and manufacturing of cantilevers based silicon technology as well as information about BioMEMS and BioNEMS are provided. Finally, overall tends in research, development and commercialization of biosensors are described briefly as well as probable areas of development in food biosensors. Thereby, this review provides an overall view of biosensors, as an exploratory guide to identify the most important aspects of this technology

Glioblastoma on a microfluidic chip: Generating pseudopalisades and enhancing aggressiveness through blood vessel obstruction events

Background: Glioblastoma (GBM) is one of the most lethal tumor types. Hypercellular regions, named pseudo- palisades, are characteristic in these tumors and have been hypothesized to be waves of migrating glioblastoma cells.These “waves” of cells are thought to be induced by oxygen and nutrient depletion caused by tumor-induced blood vessel occlusion. Although the universal presence of these structures in GBM tumors suggests that they may play an instrumental role in GBM’s spread and invasion, the recreation of these structures in vitro has remained challenging. Methods: Here we present a new microfluidic model of GBM that mimics the dynamics of pseudopalisade forma- tion.To do this, we embedded U-251 MG cells within a collagen hydrogel in a custom-designed microfluidic device. By controlling the medium flow through lateral microchannels, we can mimic and control blood-vessel obstruction events associated with this disease. Results: Through the use of this new system, we show that nutrient and oxygen starvation triggers a strong migratory process leading to pseudopalisade generation in vitro.These results validate the hypothesis of pseudo- palisade formation and show an excellent agreement with a systems-biology model based on a hypoxia-driven phenomenon. Conclusions: This paper shows the potential of microfluidic devices as advanced artificial systems capable of mod- eling in vivo nutrient and oxygen gradients during tumor evolution

Targeted Next-Generation Sequencing in a Large Cohort of Genetically Undiagnosed Patients with Neuromuscular Disorders in Spain

This article belongs to the Special Issue Genetic Advances in Neuromuscular Disorders: From Gene Identification to Gene Therapy.The term neuromuscular disorder (NMD) includes many genetic and acquired diseases and differential diagnosis can be challenging. Next-generation sequencing (NGS) is especially useful in this setting given the large number of possible candidate genes, the clinical, pathological, and genetic heterogeneity, the absence of an established genotype-phenotype correlation, and the exceptionally large size of some causative genes such as TTN, NEB and RYR1. We evaluated the diagnostic value of a custom targeted next-generation sequencing gene panel to study the mutational spectrum of a subset of NMD patients in Spain. In an NMD cohort of 207 patients with congenital myopathies, distal myopathies, congenital and adult-onset muscular dystrophies, and congenital myasthenic syndromes, we detected causative mutations in 102 patients (49.3%), involving 42 NMD-related genes. The most common causative genes, TTN and RYR1, accounted for almost 30% of cases. Thirty-two of the 207 patients (15.4%) carried variants of uncertain significance or had an unidentified second mutation to explain the genetic cause of the disease. In the remaining 73 patients (35.3%), no candidate variant was identified. In combination with patients’ clinical and myopathological data, the custom gene panel designed in our lab proved to be a powerful tool to diagnose patients with myopathies, muscular dystrophies and congenital myasthenic syndromes. Targeted NGS approaches enable a rapid and cost-effective analysis of NMD- related genes, offering reliable results in a short time and relegating invasive techniques to a second tier.This study was granted by FIS PI15/01898, funded by ISCIII and FEDER, ‘Una manera de hacer Europa’ and by Fundación Mutua Madrileña in the “Convocatoria de ayudas a la Investigación en Salud 2015”. It was also funded by an ACCI grant from CIBERER. Daniel Natera-de Benito is the recipient of a grant from the Instituto de Salud Carlos III (Contrato Rio Hortega, CM17/00044)