Evaluation of poly(lactic acid) and ECOVIO based biocomposites loaded with antimicrobial sodium phosphate microparticles.

Herein, biobased composite materials based on poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) as matrices, sodium hexametaphosphate microparticles (E452i, food additive microparticles, 1 and 5 wt%) as antimicrobial filler and acetyl tributyl citrate (ATBC, 15 wt%) as plasticizer, were developed for potential food packaging applications. Two set of composite films were obtained by melt-extrusion and compression molding, i) based on PLA matrix and ii) based on Ecovio® matrix (PLA/PBAT blend). Thermal characterization by thermogravimetric analysis and differential scanning calorimetry demonstrated that the incorporation of E452i particles improved thermal stability and crystallinity, while the mechanical test showed an increase in the Young's modulus. E452i particles also provide antimicrobial properties to the films against food-borne bacteria Listeria innocua and Staphylococcus aureus, with bacterial reduction percentages higher than 50 % in films with 5 wt% of particles. The films also preserved their disintegradability as demonstrated by an exhaustive characterization of the films under industrial composting conditions. Therefore, the results obtained in this work reveal the potential of these biocomposites as appropriated materials for antibacterial and compostable food packaging films.

Simulated gastrointestinal digestion of polylactic acid (PLA) biodegradable microplastics and their interaction with the gut microbiota.

The accumulation of microplastics (MPs) in the environment as well as their presence in foods and humans highlight the urgent need for studies on the effects of these particles on humans. Polylactic acid (PLA) is the most widely used bioplastic in the food industry and medical field. Despite its biodegradability, biocompatibility, and "Generally Recognized As Safe" (GRAS) status, recent animal model studies have shown that PLA MPs can alter the intestinal microbiota; however, to date, no studies have been reported on the possible gut and health consequences of its intake by humans. This work simulates the ingestion of a realistic daily amount of PLA MPs and their pass through the gastrointestinal tract by combining the INFOGEST method and the gastrointestinal simgi® model to evaluate possible effects on the human colonic microbiota composition (16S rRNA gene sequencing analysis) and metabolic functionality (lactic acid and short-chain fatty acids (SCFA) production). Although PLA MPs did not clearly alter the microbial community homeostasis, increased Bifidobacterium levels tended to increase in presence of millimetric PLA particles. Furthermore, shifts detected at the functional level suggest an alteration of microbial metabolism, and a possible biotransformation of PLA by the human microbial colonic community. Raman spectroscopy and field emission scanning electron microscopy (FESEM) characterization revealed morphological changes on the PLA MPs after the gastric phase of the digestion, and the adhesion of organic matter as well as a microbial biofilm, with surface biodegradation, after the intestinal and colonic phases. With this evidence and the emerging use of bioplastics, understanding their impact on humans and potential biodegradation through gastrointestinal digestion and the human microbiota merits critical investigation.

[Impact of COVID-19 lockdown on patients with idiopathic intracranial hypertension in Spain]. / Impacto del confinamiento por COVID-19 en pacientes con hipertensión intracraneal idiopática en España.

INTRODUCTION: The nationwide lockdown implemented in Spain in March 2020 in response to the 2019 coronavirus disease pandemic (COVID-19) could have had an effect on the clinical situation, disease management and access to care in patients with idiopathic intracranial hypertension. PATIENTS AND METHODS: A cross-sectional observational study was conducted by means of an online survey. The frequency and impact of headache, visual symptoms, dizziness, cognitive symptoms, diplopia, anxiety and depression on patients' quality of life were recorded. Disease treatment and delays experienced in accessing care were recorded. Participants were grouped according to the time elapsed since diagnosis. RESULTS: A total of 112 patients participated in the study (103 women). The average time since disease onset was 6.25 years. Headache, anxiety and depression were responsible for considerable impact in the period prior to lockdown. The impact of headache was not aggravated during lockdown, but anxiety and depression did become significantly worse. Recently diagnosed participants reported higher rates of anxiety, depression, dizziness and diplopia; chronically diagnosed participants reported a higher frequency of cognitive symptoms. CONCLUSIONS: The clinical situation of the participants deteriorated during lockdown, although the differences were smaller than previously thought. This was probably because the baseline situation was more severe than expected. Further studies are needed to clarify the medium and long-term impact of the COVID-19 pandemic on patients with idiopathic intracranial hypertension.

TITLE: Impacto del confinamiento por COVID-19 en pacientes con hipertensión intracraneal idiopática en España.Introducción. El confinamiento nacional instaurado en España en marzo de 2020 como respuesta a la pandemia por la enfermedad por coronavirus 2019 (COVID-19) pudo tener un efecto en la situación clínica, el manejo de la enfermedad y el acceso a la atención médica en pacientes con hipertensión intracraneal idiopática. Pacientes y métodos. Se realizó un estudio observacional transversal por medio de una encuesta en línea. Se registraron la frecuencia y el impacto en la calidad de vida de la cefalea, los síntomas visuales, el mareo, los síntomas cognitivos, la diplopía, la ansiedad y la depresión. Se registró el tratamiento de la enfermedad y los retrasos experimentados en el acceso a la atención médica. Se agrupó a los participantes según el tiempo de evolución desde el diagnóstico. Resultados. Participaron 112 pacientes (103 mujeres). El tiempo medio de evolución de la enfermedad fue 6,25 años. La cefalea, la ansiedad y la depresión fueron responsables de un impacto considerable en el período previo al confinamiento. El impacto de la cefalea no empeoró durante el confinamiento, pero la ansiedad y la depresión empeoraron significativamente. Los participantes diagnosticados recientemente comunicaron mayores tasas de ansiedad, depresión, mareo y diplopía; los de evolución crónica, mayor frecuencia de síntomas cognitivos. Conclusiones. La situación clínica de los participantes se deterioró durante el confinamiento, aunque las diferencias fueron menores de lo que se pensaba. Esto se debió, probablemente, a que la situación basal era más grave de lo esperado. Son necesarios más estudios para aclarar el impacto a medio y largo plazo de la pandemia por COVID-19 en pacientes con hipertensión intracraneal idiopática.

Temperature Assessment Of Microwave-Enhanced Heating Processes.

In this study, real-time and in-situ permittivity measurements under intense microwave electromagnetic fields are proposed as a powerful technique for the study of microwave-enhanced thermal processes in materials. In order to draw reliable conclusions about the temperatures at which transformations occur, we address how to accurately measure the bulk temperature of the samples under microwave irradiation. A new temperature calibration method merging data from four independent techniques is developed to obtain the bulk temperature as a function of the surface temperature in thermal processes under microwave conditions. Additionally, other analysis techniques such as Differential Thermal Analysis (DTA) or Raman spectroscopy are correlated to dielectric permittivity measurements and the temperatures of thermal transitions observed using each technique are compared. Our findings reveal that the combination of all these procedures could help prove the existence of specific non-thermal microwave effects in a scientifically meaningful way.

A simple vibrating sample magnetometer for macroscopic samples.

We here present a simple model of a vibrating sample magnetometer (VSM). The system allows recording magnetization curves at room temperature with a resolution of the order of 0.01 emu and is appropriated for macroscopic samples. The setup can be mounted with different configurations depending on the requirements of the sample to be measured (mass, saturation magnetization, saturation field, etc.). We also include here examples of curves obtained with our setup and comparison curves measured with a standard commercial VSM that confirms the reliability of our device.

One-step preparation of novel 1-(N-indolyl)-1,3-butadienes by base-catalysed isomerization of alkynes as an access to 5-(N-indolyl)-naphthoquinones.

A series of novel 1-(N-indolyl)-1,3-butadienes, as (1 : 1) mixtures of the (E) and (Z) dienes, was prepared in one step by base-catalysed isomerization of N-alkylindoles with a terminal butyne chain. The reaction conditions are mild, and in all cases the yields were very high (>90%). The (E) and (Z) dienes were separable by preparative TLC and could be fully characterized. This isomerization proceeded readily in the case of a butynyl chain, but didn't take place with a pentynyl chain. A mechanism was proposed for this reaction, based on previous studies on the isomerization of alkynes in basic media, and a key intermediate that supports the proposed mechanism could be isolated and fully characterized. A theoretical study of the proposed mechanism was performed by computational methods and the results validated the proposal. The reactivity of the synthesized dienes was studied in Diels-Alder reactions with p-benzoquinone, to obtain a small library of new 5-(N-indolyl)-1,4-naphthoquinones.The lack of reactivity in the case of the (Z) isomers was explained by calculation of the rotational curves of the central bond of the (Z) and (E) dienes. Finally, the cytotoxicity of the new 5-(N-indolyl)-1,4-naphthoquinones was tested against a panel of three cell lines.

Reprint of Unaltered reversible magnetic transition in Fe nanostructures upon ambient exposure.

High aspect-ratio Fe nanostrips are known to reversibly switch from a single-domain magnetic state to a multidomain diamond pattern as a function of temperature (T) and width. This magnetic bistability can be understood by the temperature-dependent balance between magnetocrystalline, shape and magnetoelastic anisotropies and has potential applications in magnetic logic devices. However, as Fe nanostructures easily oxidize, protecting the surface with capping layers may be required, which could largely affect the anisotropy balance. Here, we employ x-ray magnetic circular dichroism-photoemission electron microscopy (XMCD-PEEM) to study these thin Fe nanostrips before and after exposure to air.

Unaltered reversible magnetic transition in Fe nanostructures upon ambient exposure.

High aspect-ratio Fe nanostrips are known to reversibly switch from a single-domain magnetic state to a multidomain diamond pattern as a function of temperature (T) and width. This magnetic bistability can be understood by the temperature-dependent balance between magnetocrystalline, shape and magnetoelastic anisotropies and has potential applications in magnetic logic devices. However, as Fe nanostructures easily oxidize, protecting the surface with capping layers may be required, which could largely affect the anisotropy balance. Here, we employ x-ray magnetic circular dichroism-photoemission electron microscopy (XMCD-PEEM) to study these thin Fe nanostrips before and after exposure to air.

Esophageal lesions detected during small bowel capsule endoscopy : incidence, diagnostic and therapeutic impact.

BACKGROUND: Nowadays, capsule endoscopy is the first-line procedure for the visualization of the small bowel. Although it was primarily designed with this goal, it may also identify other segments of the gastrointestinal tract. The aim of the current study is to evaluate the incidence of esophageal abnormalities detected in patients undergoing small bowel capsule endoscopy and its impact on patient management. PATIENTS AND METHODS: This study is a retrospective analysis of data from 2217 consecutive capsule endoscopy procedures performed at a single tertiary-care centre between January 2008 and February 2016. Patient baseline characteristics, esophageal lesions, diagnosis and management before and after capsule endoscopy were recorded and a descriptive analysis was then performed. RESULTS: 2217 patients were finally included in the analysis. 1070 were male (48.2%) and the mean age was 56.1 ± 19.5 years (12-93). Obscure gastrointestinal bleeding (52.3%) and inflammatory bowel disease (18.3%) were the main procedure indications. Esophageal abnormalities were detected in 105 out of 2217 patients (4.7%). The most common lesions detected were peptic esophagitis (58.1%) and esophageal varices (17.1%). This information had a clinical/diagnostic impact of 3.3% and a therapeutic impact of 3.2%. CONCLUSION: Capsule endoscopy detects not only small bowel lesions, but also significant esophageal lesions that may be overlooked during initial gastroscopy. Therefore, all images of the esophagus should be read during small bowel capsule endoscopy, since it could provide relevant information that may result in changes on patient´s management.

[Non-small bowel lesions detected with capsule endoscopy in patients with obscure gastrointestinal bleeding]. / Detección de lesiones fuera del intestino delgado con cápsula endoscópica en pacientes con hemorragia digestiva oculta.

Obscure gastrointestinal bleeding accounts for approximately 5-10% of patients presenting with gastrointestinal haemorrhage. The majority of lesions responsible were found to be located in the small bowel. Currently, capsule en-doscopy is the first-line tool to investigate the small bowel as it is a non-invasive, feasible and simple procedure. Howe-ver, capsule endoscopy sometimes identifies the source of bleeding outside the small bowel and within the reach of conventional endoscopy. We present the case of a 46 year-old man with few prior negative endoscopic procedures and iron-deficiency anaemia due to gastric GIST.

Utilization of Anabaena sp. in CO2 removal processes: modelling of biomass, exopolysaccharides productivities and CO2 fixation rate.

This paper focuses on modelling the growth rate and exopolysaccharides production of Anabaena sp. ATCC 33047, to be used in carbon dioxide removal and biofuels production. For this, the influence of dilution rate, irradiance and aeration rate on the biomass and exopolysaccharides productivity, as well as on the CO(2) fixation rate, have been studied. The productivity of the cultures was maximum at the highest irradiance and dilution rate assayed, resulting to 0.5 g(bio) l(-1) day(-1) and 0.2 g(eps) l(-1) day(-1), and the CO(2) fixation rate measured was 1.0 gCO(2) l(-1) day(-1). The results showed that although Anabaena sp. was partially photo-inhibited at irradiances higher than 1,300 µE m(-2) s(-1), its growth rate increases hyperbolically with the average irradiance inside the culture, and so does the specific exopolysaccharides production rate. The latter, on the other hand, decreases under high external irradiances, indicating that the exopolysaccharides metabolism hindered by photo-damage. Mathematical models that consider these phenomena have been proposed. Regarding aeration, the yield of the cultures decreased at rates over 0.5 v/v/min or when shear rates were higher than 60 s(-1), demonstrating the existence of thus existence of stress damage by aeration. The behaviour of the cultures has been verified outdoors in a pilot-scale airlift tubular photobioreactor. From this study it is concluded that Anabaena sp. is highly recommended to transform CO(2) into valuable products as has been proved capable of metabolizing carbon dioxide at rates of 1.2 gCO(2) l(-1) day(-1) outdoors. The adequacy of the proposed equations is demonstrated, resulting to a useful tool in the design and operation of photobioreactors using this strain.

Development of a process for efficient use of CO2 from flue gases in the production of photosynthetic microorganisms.

A new methodology to use efficiently flue gases as CO(2) source in the production of photosynthetic microorganisms is proposed. The CO(2) is absorbed in an aqueous phase that is then regenerated by microalgae. Carbonated solutions could absorb up to 80% of the CO(2) from diluted gas reaching total inorganic carbon (TIC) concentrations up to 2.0 g/L. The pH of the solution was maintained at 8.0-10.0 by the bicarbonate/carbonate buffer, so it is compatible with biological regeneration. The absorption process was modeled and the kinetic parameters were determined. Anabaena sp. demonstrated to tolerate pH (8.0-10.0) and TIC (up to 2.0 g/L) conditions imposed by the absorption step. Experiments of regeneration of the liquid phase demonstrated the feasibility of the overall process, converting CO(2) into organic matter. The developed process avoids heating to regenerate the liquid whereas maximizing the efficiency of CO(2) use, which is relevant to achieve the commercial production of biofuels from microalgae.

Reaction pathways for hydrogen desorption from magnesium hydride/hydroxide composites: bulk and interface effects.

This manuscript investigates the thermal desorption behaviour of MgH(2)/Mg(OH)(2) composites by means of thermal desorption spectroscopy. Besides the H(2)O and H(2) desorption events due to Mg(OH)(2) dehydration and MgH(2) decomposition reactions, respectively, two additional H(2) desorption peaks arise at lower temperatures. These peaks are related to solid-state reactions between magnesium hydride and magnesium hydroxide through different channels. The low temperature H(2) peak ( approximately 150 degrees C) is related to reaction between a H atom diffusing from MgH(2) and a surface OH group, whereas the intermediate temperature H(2) peak ( approximately 350 degrees C) is due to an interface reaction between the hydride and the hydroxide. The present work supports the theory that the onset of the H(2) desorption coming from MgH(2) decomposition is controlled by an incubation process, consisting in the formation of catalytically active vacancies at the MgO/Mg(OH)(2) surface by dehydration. Possible ways to improve the H(2) desorption kinetics from MgH(2) are discussed in the light of the results obtained.

Utilization of the cyanobacteria Anabaena sp. ATCC 33047 in CO2 removal processes.

In this paper the utilization of the cyanobacteria Anabaena sp. in carbon dioxide removal processes is evaluated. For this, continuous cultures of this strain were performed at different dilution rates; alternatives for the recovery of the organic matter produced being also studied. A maximum CO(2) fixation rate of 1.45 g CO(2) L(-1) day(-1) was measured experimentally, but it can be increased up to 3.0 g CO(2) L(-1) day(-1) outdoors. The CO(2) is mainly transformed into exopolysaccharides, biomass representing one third of the total organic matter produced. Organic matter can be recovered by sedimentation with efficiencies higher than 90%, the velocity of sedimentation being 2.10(-4) s(-1). The major compounds were carbohydrates and proteins with productivities of 0.70 and 0.12 g L(-1) day(-1), respectively. The behaviour of the cultures of Anabaena sp. has been modelized, also the characteristics parameters requested to design separation units being reported. Finally, to valorizate the organic matter as biofertilizers and biofuels is proposed.

Ultrasonic irradiation as a tool to modify the H-desorption from hydrides: MgH(2) suspended in decane.

Effects of ultrasonic irradiation on magnesium hydride (MgH(2)) suspended in decane were investigated with the purpose of improving its hydrogen desorption process. Firstly, we have found that the presence of MgH(2) improves the sonolysis of decane enhancing the amount of hydrogen evolved during the sonication process. The sonicated-MgH(2) maintains its microstructural properties practically unaltered but a drastic reduction of the particle size of MgH(2) (down to approximately 20mum) as well as a high pressure MgH(2) phase are observed. However, no substantial modifications of H-kinetic properties of hydride occur as is determined by thermal desorption measurements. This could be attributed to decomposition of decane during sonication which leads to the formation of carbon compounds that hinder the thermal decomposition of MgH(2).

Interface double-exchange ferromagnetism in the Mn-Zn-O system: new class of biphase magnetism.

In this Letter, we experimentally show that the room temperature ferromagnetism in the Mn-Zn-O system recently observed is associated with the coexistence of Mn(3+) and Mn(4+) via a double-exchange mechanism. The presence of the ZnO around MnO(2) modifies the kinetics of MnO(2)-->Mn(2)O(3) reduction and favors the coexistence of both Mn oxidation states. The ferromagnetic phase is associated with the interface formed at the Zn diffusion front into Mn oxide, corroborated by preparing thin film multilayers that exhibit saturation magnetization 2 orders of magnitude higher than bulk samples.

Nanostructure and magnetic properties of the MnZnO system, a room temperature magnetic semiconductor?

The magnetic properties of the system MnZnO prepared by conventional ceramic procedures using ZnO and MnO(2) starting powders are studied and related to the nanostructure. Thermal treatment at 500 °C produces a ferromagnetic phase, although this temperature is not high enough to promote proper sintering; thus the thermally treated compact shows brittle characteristics of unreacted and poorly densified ceramic samples. Scanning electron microscopy and x-ray analysis reveal the appearance of a new phase, most probably related to the diffusion of Zn into MnO(2) oxide nanocrystals. The magnetic properties deviate considerably from what would be expected of an unreacted mixture of ZnO (diamagnetic) and MnO(2) particles (paramagnetic above 100 K and anti-ferromagnetic below that temperature), exhibiting a ferromagnetic like behaviour from 5 to 300 K and beyond mixed with a paramagnetic component. The ferromagnetic phase seems to be originated by diffusion at the nanoscale of Zn into MnO(2) grains. The Curie temperature of the ferromagnetic phase, once the paramagnetic component has been subtracted from the hysteresis loops, is measured to be 450 K. EPR resonance experiments from 100 to 600 K confirm a ferromagnetic to paramagnetic like transition above room temperature for these materials.