El objetivo de esta investigación consistió en cuantificar mediante Espectrofotometría UV-Visible, el contenido de nitritos en productos embutidos de tipo jamón, distribuidos en la zona central de Honduras, para generar una alerta en cuanto a su consumo. Para su alcance, se empleó instrumentos descriptivos tipo encuesta para valorar el nivel de preferencia y la técnica de espectrofotometría a una longitud de onda de 540 nm para evaluar el contenido de nitritos en tres diferentes tratamientos. Los resultados sugieren que los productos embutidos de mayor aceptación por el consumidor son los de tipo jamón, principalmente aquellos que se elaboran a partir de carne de pollo. De igual manera esta investigación genera una alerta sobre la salud del consumidor, en vista que dos terceras partes de las marcas comerciales empleadas para esta investigación, no cumplen con la normativa de uso de aditivos, según lo establecido por el Codex Alimentarius.

In the aerospace industry, the performance of materials on extreme conditions is crucial. This study addresses the development of nanoparticle-reinforced composite materials to improve thermal properties and flame retardancy in aerospace applications. As first approach, Zinc oxide (ZnO) nanoparticles were synthesized and incorporated into carbon fibers through the dip coating process. Subsequently, composite laminates were manufactured using the vacuum bag infusion method. The materials were subjected to flammability tests, following FAA regulations, to evaluate their performance against flame spread. The laminates reinforced with ZnO presented promise performances, suggesting a need for optimization in the incorporation of nanoparticles for safer and more efficient applications in the aerospace industry.

BackgroundLong-term sequelae are frequent and often disabling after epidermal necrolysis (Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)). However, consensus on the modalities of management of these sequelae is lacking.ObjectivesWe conducted an international multicentric DELPHI exercise to establish a multidisciplinary expert consensus to standardize recommendations regarding management of SJS/TEN sequelae.MethodsParticipants were sent a survey via the online tool "Survey Monkey" consisting of 54 statements organized into 8 topics: general recommendations, professionals involved, skin, oral mucosa and teeth, eyes, genital area, mental health, and allergy workup. Participants evaluated the level of appropriateness of each statement on a scale of 1 (extremely inappropriate) to 9 (extremely appropriate). Results were analyzed according to the RAND/UCLA Appropriateness Method.ResultsFifty-two healthcare professionals participated. After the first round, a consensus was obtained for 100% of 54 initially proposed statements (disagreement index < 1). Among them, 50 statements were agreed upon as 'appropriate'; four statements were considered 'uncertain', and ultimately finally discarded.ConclusionsOur DELPHI-based expert consensus should help guide physicians in conducting a prolonged multidisciplinary follow-up of sequelae in SJS-TEN.

In the design and fabrication of any structural system for space application, balance between mass, stiffness and strength is crucial. Structures in space environments are exposed to high radiation levels and thermal shock, due to the sun irradiance and rotation around Earth. Therefore, accurate determination of the thermal and radiation properties is a key issue for the materials used in such applications. This study reports the thermal and mechanical performance of particle composites (epoxy resin and ZnO particles) after gamma and UV radiation. Composites are exposed to gamma and UV radiation at rates of 1 kGy and 10 kGy and characterized after exposure. For the evaluation, DMA, TGA and three-point bending mechanical test are performed to determine thermal properties and possible material degradation after radiation exposure. The incorporation of the filler in the thermal, radiation and mechanical response of the epoxy system improves as a function of its concentration. Then, epoxy resin reinforced with ZnO particles can be a potential candidate as a polymeric matrix for fiber-reinforced composites for nanosatellites.

Describe an educational opportunity for RDNs to contribute to understanding of the role of nutrition in patient care for future physicians.

Biolaminates of Ixtle and Henequen natural fibers reinforced bio-based epoxy resin were prepared using Vacuum Assisted Resin Infusion process. ZnO nanoparticles were added to the bio-based epoxy resin at 1, 2 and 3 wt. % content before impregnation process. The viscoelastic and mechanical properties, as well as the fracture behavior, were evaluated and related to the nature of the fibers and filler content. The viscoelastic results indicated the ZnO particles are effective fillers just at low concentrations, and induce different reinforcement mechanisms attributed to the interaction between the nature of fibers and nanoparticles. The mechanical properties of the Ixtle biolaminates decreased at higher filler concentrations, while Henequen biolaminates showed better mechanical properties just above the 2 wt. % of ZnO. The fracture behavior in mode I registered moderate changes in toughness, related to the ZnO fraction, which promoted different behaviors on the interlaminar adherence of the layers. The results point to the need to continue evaluating the potential application of these green composites for their use in construction and automotive industries.

This work reports the in situ instrumentation from manufacturing to loading of a henequen fiber woven-bioepoxy composite. Continuous monitoring was performed by means of fiber Bragg gratings (FBG) with the aim of tracking the curing behavior of the biolaminate by vacuum-assisted resin infusion (VARI). The instrumented composite was later tested mechanically under bending. Among the results obtained, micro-deformations were detected as a consequence of curing residual stresses, and when tested, the FBG data had similarity with the strain calculated according to the ASTM D7264/D7264M standard.

Natural fibers are a low-cost renewable resource; they are not toxic, low density, not abrasive effects like glass fibers, and biodegradable. Besides, nanoparticles' use as reinforcement allows increasing the mechanical and thermal properties of these materials. In this work, the mechanical properties of Ixtle natural fiber composite biolaminates embedded in an epoxy resin with 45% natural component and reinforced with zinc oxide nanoparticles in different percentages by weight are evaluated. The mechanical properties showed an increase in stiffness and resistance with the presence of nanoparticles. The mode I fracture behavior registered a slight decrease in toughness as the nanoparticle content increased, promoted by the inhibition of interlaminar adhesion.

Abstract Background Cardiopulmonary exercise test (CPET) and exercise Doppler echocardiography (EDE) may be useful for the early detection of pulmonary hypertension in systemic sclerosis (SSc) Aim To assess the feasibility of CPET and EDE in detecting early changes in gas exchange and/or pulmonary hemodynamics in SSc Methods From 2016 to 2021, we evaluated 19 SSc patients (Group 1, age = 52.58±11.27, women 17 (89.5%)), and age 32.10±6.67, men 17 (89.4%) matched healthy controls (Group 2). Simultaneous CPET and EDE were performed. With CPET, we assessed peak oxygen uptake (VO2), peak respiratory quotient (RQ), respiratory equivalent ratio for carbonic gas (VE/VCO2), and maximal respiratory equivalent divided by maximal ventilatory ventilation (V̇E Max/VVM). With EDE, we assessed tricuspid regurgitant velocity (TRV) jet and pulmonary flow acceleration time (ACT) to derive systolic pulmonary arterial pressure (SPAP). Results Exercise duration was similar in the 2 groups (Group 1 = 9.2±2.93 vs Group 2 = 10.14±1.78 minutes). Among CPET parameters, SSc patients showed lower peak VO2 (Group 1 = 1.23±0.55 vs Group 2 = 2.45±0.7, p<0.001), similar RQ (1.10±0.10 vs 1.17±0.09;. p=0.036), VE/VCO2 (Group 1 = 31.90±3.65 vs Group 2 = 23.79±2.64, p<0.001) and V̇E Max/VVM (Group 1 = 1.93±0.60 vs Group 2 = 1.76±0.36, p=NS). With EDE, feasibility at peak stress was low for TRV (Group 1 = 42% vs Group 2 = 58%, p=NS), moderate for ACT (Group 1 = 53% vs Group 2 = 78%, p=NS) and high when at least one was technically adequate (Group 1 = 73% vs Group 2 = 100%, p<0.001). Rest TRV (Group 1 = 2.48±0.14 vs Group 2 = 2.08±0.12 m/s, p=0.033) and ACT (Group 1 = 100.14±10.63 vs Group 2 = 108.86±6.38 ms, p=0.482) showed similar values in the 2 groups (será que ficou similar?). During stress, TRV increased more markedly in SSc (Group 1 = 3.33±0.32 vs Group 2 = 2.34±0.09 m/s, p=0.004) and ACT decreased (Group 1 = 81.9±6.54 vs 73.39±5.18 ms, p=0.304), with estimated peak SPAP higher in SSc (Group 1 = 53.34±7.88 vs Group 2 = 43.33±5.49, p<0.001): see figure. Conclusion CPET and EDE offer complementary information on gas exchange and pulmonary hemodynamics in SSc and can detect early alterations missed by resting assessment. The success rate of EDE increases significantly with the combination of TRV and ACT. Funding Acknowledgement Type of funding sources: None.

Abstract Funding Acknowledgements Type of funding sources: None. Background A blunted heart rate reserve (HRR) during dobutamine stress echo (DSE) is an index of altered cardiac sympathetic reserve, which is frequently present in diabetes mellitus (DM) or chronic kidney disease (CKD). Aim To assess the prognostic value of HRR during DSE. Methods We recruited 280 patients (pts) (mean age 62.9 ± 13.1 years); 128 (45.7%) male; 28.2% on beta-blockers at the time of testing) who underwent DSE for known or suspected coronary artery disease and/or heart failure and were followed-up. Four subsets were identified: Group 1 (111 pts without DM or CKD); group 2 (37 with DM without CKD); group 3 (90 with CKD with or without DM); and group 4 (42 with CKD on dialysis). HRR was calculated by EKG as the peak/rest HR ratio. Results Ischemia was identified in 34/280 (12.1%) pts. During a median follow-up time of 40.3 ± 30.5 months, 120 events occurred: 46 deaths, 15 non-fatal myocardial infarctions, 23 hospital admissions for acute decompensated heart failure, and 36 myocardial revascularizations. Multivariable comparison of HRR among the 4 groups using post hoc test showed a blunted HRR in group 3 (1.66 ± 0.32) and 4 (1.65 ± 0.27) when compared with group 1 (HRR 1.85 ± 0.35), p < 0.01. Group 2 (1.73 ± 0.28) was not different from any group (p = ns). Groups 3 and 4 were not different between them (p = ns). A post hoc Tukey test for HRR separated in tercils, 1st: HRR < 1.59, 2nd: 1.59 < HRR < 1.86 and 3rd: HRR > 1.86 (p < 0.000). Kaplan-Meier curves showed blunted HRR as an independent predictor of event-free survival in the overall group - 1st: 66.08 ± 5.9 months, 95% CI 54.3-77.7; 2nd: 69.52 ± 6.5, 95% CI 56.6-82.3; 3rd: 90.05 ± 5.3, 95% CI 79.5-100.5. See Figure. HRR was comparable in patients with and without inducible ischemia and off or on beta-blockers. Conclusion A blunted HRR during DSE is frequent in patients with DM and CKD, independent of inducible ischemia and use of beta-blockers, and is a useful non-imaging predictor of adverse events. Abstract Figure. HR ratio and event-free survival curves

The phenomena occurring during curing process is one of the major issues to deal in order to improve the physical properties of a composite structure. In this work, a multi-instrumentation setup is conceived in order to have a better understanding of composites curing using different devices (tunnelling junction sensors, optical fibres and flexible ultrasonic transducers). The sensors are simultaneously embedded or placed on the surface of a thick carbon-epoxy plate for monitoring its autoclave cycle. By means of all signals, an evolution of temperature, internal strains and physical state changes is described. A qualitative statement from all measurements is provided to have a first approach of the initial state of the composite plate. With this methodology, the initial state after composite manufacturing can be considered in the structure design procedure to improve its mechanical performance. (C) 2020 Elsevier Ltd. All rights reserved.

An experimental-numerical methodology for failure analysis of the c-Al0.66Ti0.34N/Interface/M2 steel coating system is proposed here. This c-Al0.66Ti0.34N coating was deposited by the arc-PVD technique. The values of the elastic modulus, the fracture energy release rate and the nano-hardness of the coating were obtained by nanoindentation. Normal and shear stress limits of the interface, as well as the adhesive and cohesive critical loads, were measured with the scratch test method. A finite element analysis, using the experimental mechanical properties, was carried out to understand the relationship between the irreversible work vs. depth curve and the mechanical failure evolution of the coating-substrate system, associating the pop-in with nucleation, crack growth and cracking pattern. Extended finite element method (XFEM) was applied for modeling of the mechanical behavior of the coating; the cohesive zones approach was applied for modeling the interface and the Ramberg-Osgood law for modeling the substrate. This approach proposes an experimental-numerical methodology for failure analysis of hard coatings (monolithic body) allowing to calculate fracture energy of the coating material and to model cracking patterns caused by contact mechanics. This work is the first step to answer questions about multi-scale approaches for multi-functional multi-layer coatings to push their enhancements and further applications.

Mesenchymal stem cell (MSC)-based therapy is being increasingly considered a powerful opportunity for several disorders based on MSC immunoregulatory properties. Nonetheless, MSC are versatile and plastic cells that require an efficient control of their features and functions for their optimal use in clinic. Recently, we have shown that PPARβ/δ is pivotal for MSC immunoregulatory and therapeutic functions. However, the role of PPARβ/δ on MSC metabolic activity and the relevance of PPARβ/δ metabolic control on MSC immunosuppressive properties have never been addressed. Here, we demonstrate that PPARβ/δ deficiency forces MSC metabolic adaptation increasing their glycolytic activity required for their immunoregulatory functions on Th1 and Th17 cells. Additionally, we show that the inhibition of the mitochondrial production of ATP in MSC expressing PPARβ/δ, promotes their metabolic switch towards aerobic glycolysis to stably enhance their immunosuppressive capacities significantly. Altogether, these data demonstrate that PPARβ/δ governs the immunoregulatory potential of MSC by dictating their metabolic reprogramming and pave the way for enhancing MSC immunoregulatory properties and counteracting their versatility.

A thermal computational analysis for the composite structure of a CubeSat is presented. The main purpose of this investigation is to study the thermal performance of carbon fibre/epoxy resin composite materials with Zinc Oxide nanoparticles in order to be used in the panels of the primary structure of a CubeSat. The radiative heat fluxes over each composite panel are computed according to the orbit trajectory and they are utilized as boundary conditions for the analysis. The direct solar, albedo and Earth infrared radiation fluxes are considered in this study. The model implementation, including the computation of the orthotropic thermal conductivity of the composite material is presented. The thermal simulations were performed for three different orbit inclination angles: the selected mission ( β = 57 ∘ ), the worst hot ( β = 90 ∘ ) and the worst cold ( β = 0 ∘ ). The temperature ranges in the electronic boards are analyzed in order to show that are into the operating limits of each electronic component.

This review summarizes the current state-of-art of real-time instrumentation of Resin Transfer Moulding (RTM). As RTM is gaining demand in the aerospace industry because of its higher properties-cost ratio compared with autoclave, better process monitoring and parameters tracking are required. RTM incorporates composite design flexibility and fast-medium volume production improving manufacturing efficiencies on a buy-to-fly sector. After an analysis of current composite monitoring technologies, the review states two major technologies due to its information-cost performance: electric devices (thermocouples, pressure transducers and dielectric sensors) and light devices (optical fibres). The use of one or another is defined by the engineering requirements of the final part, the initial investment on monitoring infrastructure and the accuracy and relevance of the acquired information. Afterwards, the successful incorporation of sensors in the RTM process will help on future innovation on liquid filling strategies, development of preforming techniques and novel multiscale numerical modelling approaches.

This work describes the technological and scientific efforts on designing, manufacturing and testing validation for high performance-low cost composite structures for Light Sport Aircrafts (LSA). A Mexican initiative to conceive, manufacture and assembly a Light Sport Aircraft has been developed by using Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA) and Liquid Composite Manufacturing (LCM). These consolidated techniques are used to characterize novel approaches to manufacturing and assembly carbon-fiber based structural components. As large structures are manufactured via Vacuum Assisted Resin Infusion (VARI), impregnation strategies are studied to minimize inner flaws and also to improve the manufacturing time and surface quality of each component. The first case of study, to validate this methodology, involves non-structural components such as the cowling. Control surfaces (ailerons, rudder, elevator and flaps) have been manufactured, each of them having common issues but also unique challenges. As an example, a second case of study, the aileron main beam is analyzed. Furthermore, test portfolio will be developed with the goal to perform 1-to-1 scale mechanical tests for validation in compliance with ASTM standards.