Acrylonitrile butadiene styrene-based composites with permalloy with tailored magnetic response

This work reports on tailoring the magnetic properties of acrylonitrile butadiene styrene (ABS)-based composites for their application in magnetoactive systems, such as magnetic sensors and actuators. The magnetic properties of the composites are provided by the inclusion of varying permalloy (Py—Ni75Fe20Mo5) nanoparticle content within the ABS matrix. Composites with Py nanoparticle content up to 80 wt% were prepared and their morphological, mechanical, thermal, dielectric and magnetic properties were evaluated. It was found that ABS shows the capability to include high loads of the filler without negatively influencing its thermal and mechanical properties. In fact, the thermal properties of the ABS matrix are basically unaltered with the inclusion of the Py nanoparticles, with the glass transition temperatures of pristine ABS and its composites remaining around 105 °C. The mechanical properties of the composites depend on filler content, with the Young’s modulus ranging from 1.16 GPa for the pristine ABS up to 1.98 GPa for the sample with 60 wt% filler content. Regarding the magnetic properties, the saturation magnetization of the composites increased linearly with increasing Py content up to a value of 50.9 emu/g for the samples with 80 wt% of Py content. A numerical model has been developed to support the findings about the magnetic behavior of the NP within the ABS. Overall, the slight improvement in the mechanical properties and the magnetic properties provides the ABS composites new possibilities for applications in magnetoactive systems, including magnetic sensors, actuators and magnetic field shielding.This project was supported by the PID program CDTI (EXP-00131900/IDI-20210369). Funding is from the Basque Government Industry Department under the ELKARTEK program. Support was received from the Portuguese Fundação para a Ciência e Tecnologia, grant SFRH/BPD/110914/2015

Electrospun magnetic ionic liquid based electroactive materials for tissue engineering applications

Functional electrospun fibers incorporating ionic liquids (ILs) present a novel approach in the development of active microenviroments due to their ability to respond to external magnetic fields without the addition of magnetic particles. In this context, this work reports on the development of magnetically responsive magneto-ionic fibers based on the electroactive polymer poly(vinylidene fluoride) and the magnetic IL (MIL), bis(1-butyl-3-methylimidazolium) tetrathiocyanatocobaltate ([Bmim]2[(SCN)4Co]). The PVDF/MIL electrospun fibers were prepared incorporating 5, 10 and 15 wt.% of the MIL, showing that the inclusion of the MIL increases the polar β-phase content of the polymer from 79% to 94% and decreases the crystallinity of the fibers from 47% to 36%. Furthermore, the thermal stability of the fibers decreases with the incorporation of the MIL. The magnetization of the PVDF/MIL composite fibers is proportional to the MIL content and decreases with temperature. Finally, cytotoxicity assays show a decrease in cell viability with increasing the MIL content.This research was funded by FCT—Fundação para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UID/FIS/04650/2020, and project PTDC/BTM-MAT/28237/2017. Moreover, the authors thank FCT for the research grant SFRH/BD/145345/2019 (LMC), SFRH/BD/148655/2019 (RMM), and D.M.C. and CR thank the FCT for the contract under the Stimulus of Scientific Employment 2020.02915.CEECIND and 2020.04163.CEECIND, respectively.The authors acknowledge funding by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry Departments under the ELKARTEK program. Technical and human support provided by IZO-SGI, SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) is gratefully acknowledged

Aislamiento y caracterización de Escherichia coliO157:H7 a partir de carne molida de bovino en Lima-Perú

The aim of the study was to isolate and characterize E. coli O157: H7 from fresh ground beef obtained in different food markets. 195 samples were analyzed, for isolation and enumeration of E. coliwas used most probable number technique using multiple tubes, for the isolation and characterization of E. coliO157: H7 selective enrichment and biochemical analysis, characteristic colonies were confirmed serologically. To determine the presence of shigatoxin (stx1, stx2) and intimin (eaeA) was done with multiplex real time PCR and for enterohemolysin the hemolysis test. The 87.18% of the samples were positive for E. coliand 77.95% had a count greater than or equal to 50 NMP/g. Were obtained 3 (1.54%) strains of E. coliO157: H7, one stx1 +/stx2 +/eaeA - and enterohemolysin -, one stx1 +/stx2 -/eaeA + and enterohemolysin - and the other stx1 -/stx2 -/eaeA - and enterohemolysin +. Also obtained 4 (2.05%) strains of E. coliO157 non H7, no virulence factors presented. The study found that the risk potential E. coliO157: H7 affecting the population of LimaEl objetivo del estudio fue aislar y caracterizar E. coliO157:H7 a partir de carne molida fresca de bovino obtenida en diferentes mercados de abastos. Se analizaron 195 muestras; para el aislamiento y enumeración de E. coli se utilizó la técnica del Numero Más probable mediante tubos múltiples; para el aislamiento y caracterización de E. coliO157:H7 el enriquecimiento selectivo y el análisis bioquímico, las colonias características se confirmaron mediante pruebas serológicas. Para determinar la presencia de shigatoxina (stx1, stx2) e intimina (eae A) se empleó la técnica de PCR multiplex en tiempo real y para enterohemolisina la prueba de hemólisis. El 87.18% de la muestras fue positivo para E. coliy el 77.95% presentó un recuento igual o superior a 50 NMP/g. Se obtuvieron 3 (1.54%) cepas de E. coliO157:H7, una stx1 +/ stx2 +/ eaeA – y enterohemolisina -, una stx1 +/ stx2 -/ eaeA + y enterohemolisina – y la otra stx1 -/ stx2 -/ eaeA – y enterohemolisina +. También se obtuvieron 4 cepas (2.05%) de E. coli O157 no H7, ninguna presentó factores de virulencia. El estudio reveló el riesgo potencial de que E. coliO157:H7 afecte a la población de Lima

Beeswax multifunctional composites with thermal-healing capability and recyclability

Natural beeswax reinforced with conductive nanofillers allows solvent-free processing and presents remarkable functional response as piezoresistive and thermoresistive sensors with thermal healing capability. The low melting temperature of the composites, around 60 °C, allows additive manufacturing of conductive patterns with a high electrical conductivity of 50 S/m. Further, the graphene/beeswax composites show suitable deformation and temperature sensing characteristics based on the piezoresistive and thermoresistive sensitivities, around GF≈9 and S≈ 120 %/°C, respectively. Natural beeswax is a food and drug administration approved substance, and all graphene/beeswax composites present no cytotoxic behavior, demonstrating their potential use for biomedical applications. Proofs-of-concept demonstrate the conductive and thermal-healing properties of the screen-printed sensors developed both on paper and Kapton substrates, proving the applicability and multifunctionality of the developed materials. Finally, the multifunctional composites can be recycled and reused without losing their electrical and functional performances

Recombinant human leptin treatment in genetic lipodystrophic syndromes: the long-term Spanish experience

Lipodystrophies are a group of diseases mainly characterized by a loss of adipose tissue and frequently associated with insulin resistance, hypertriglyceridemia, and hepatic steatosis. In uncommon lipodystrophies, these complications frequently are difficult to control with conventional therapeutic approaches. This retrospective study addressed the effectiveness of recombinant methionyl leptin (metreleptin) for improving glucose metabolism, lipid profile, and hepatic steatosis in patients with genetic lipodystrophic syndromes. We studied nine patients (five females and four males) with genetic lipodystrophies [seven with Berardinelli-Seip syndrome, one with atypical progeroid syndrome, and one with type 2 familial partial lipodystrophy (FPLD)]. Six patients were children under age 9 years, and all patients had baseline triglycerides levels >2.26 mmol/L and hepatic steatosis; six had poorly controlled diabetes mellitus. Metreleptin was self-administered subcutaneously daily at a final dose that ranged between 0.05 and 0.24 mg/(kg day) [median: 0.08 mg/(kg day)] according to the body weight. The duration of treatment ranged from 9 months to 5 years, 9 months (median: 3 years). Plasma glucose, hemoglobin A1c (Hb A1c), lipid profile, plasma insulin and leptin, and hepatic enzymes were evaluated at baseline and at least every 6 months. Except for the patient with FPLD, metreleptin replacement significantly improved metabolic control (Hb A1c: from 10.4 to 7.1 %, p < 0.05). Plasma triglycerides were reduced 76 % on average, and hepatic enzymes decreased more than 65 %. This study extends knowledge about metreleptin replacement in genetic lipodystrophies, bearing out its effectiveness for long periods of time

Rapid and improved identification of drinking water bacteria using the Drinking Water Library, a dedicated MALDI-TOF MS database

According to the European Directives (UE) 2020/2184 and 2009/54/EC, which establishes the sanitary criteria for water intended for human consumption in Europe, water suitable for human consumption must be free of the bacterial indicators Escherichia coli, Clostridium perfringens and Enterococcus spp. Drinking water is also monitored for heterotrophic bacteria, which are not a human health risk, but can serve as an index of bacteriological water quality. Therefore, a rapid, accurate, and cost-effective method for the identification of these colonies would improve our understanding of the culturable bacteria of drinking water and facilitate the task of water management by treatment facilities. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is potentially such a method, although most of the currently available mass spectral libraries have been developed in a clinical setting and have limited environmental applicability. In this work, a MALDITOF MS drinking water library (DWL) was defined and developed by targeting bacteria present in water intended for human consumption. This database, made up of 319 different bacterial strains, can contribute to the routine microbiological control of either treated drinking water or mineral bottled water carried out by water treatment and distribution operators, offering a faster identification rate compared to a clinical sample-based library. The DWL, made up of 96 bacterial genera, 44 of which are not represented in the MALDI-TOF MS bacterial Bruker Daltonics (BDAL) database, was found to significantly improve the identification of bacteria present in drinking water

Advancing Key Gaps in the Knowledge of Plasmodium vivax Cryptic Infections Using Humanized Mouse Models and Organs-on-Chips

Plasmodium vivax is the most widely distributed human malaria parasite representing 36.3% of disease burden in the South-East Asia region and the most predominant species in the region of the Americas. Recent estimates indicate that 3.3 billion of people are under risk of infection with circa 7 million clinical cases reported each year. This burden is certainly underestimated as the vast majority of chronic infections are asymptomatic. For centuries, it has been widely accepted that the only source of cryptic parasites is the liver dormant stages known as hypnozoites. However, recent evidence indicates that niches outside the liver, in particular in the spleen and the bone marrow, can represent a major source of cryptic chronic erythrocytic infections. The origin of such chronic infections is highly controversial as many key knowledge gaps remain unanswered. Yet, as parasites in these niches seem to be sheltered from immune response and antimalarial drugs, research on this area should be reinforced if elimination of malaria is to be achieved. Due to ethical and technical considerations, working with the liver, bone marrow and spleen from natural infections is very difficult. Recent advances in the development of humanized mouse models and organs-on-a-chip models, offer novel technological frontiers to study human diseases, vaccine validation and drug discovery. Here, we review current data of these frontier technologies in malaria, highlighting major challenges ahead to study P. vivax cryptic niches, which perpetuate transmission and burden