122 research outputs found
3D LES simulations of a static and vertically free-to-oscillate 4:1 rectangular cylinder: Effects of the grid resolution
Vortex induced vibration (VIV) is an important phenomenon which appears in flexible structures immersed in a moving fluid. This oscillation is self-sustained and self-limited, but VIV might cause fatigue damage and affect the structure's serviceability.In the present study, the aerodynamics of the flow fields around a static and vertically free-to-oscillate 4:1 rectangular cylinder are analysed by means of 3D LES simulations, adopting the OneEqEddy viscosity model. Integral parameters, pressure distributions, amplitudes of oscillation, coherences and correlations are obtained and compared with the available experimental data. Aiming to ascertain the impact of the boundary conditions and the grid resolution on the accuracy of results, five cases adopting 3 different meshes including two different spanwise discretisations have been considered. When studying the aerodynamics of the cylinder in static conditions, the influence of the spatial discretisation is very limited, and the agreement with experimental data is fairly good. On the other hand, for the free-to-oscillate cylinder, the structural response is dramatically dependent on the spanwise discretisation. The maximum amplitude of the structural response decreases as the mesh resolution increases, providing a closer fit with the experimental data. Also, the spanwise correlation of pressures is studied, finding remarkable differences depending on the level of spatial discretisation
Current state of insect proteins: extraction technologies, bioactive peptides and allergenicity of edible insect proteins.
This review aims to provide an updated overview of edible insect proteins and the bioactivity of insect-derived peptides. The essential amino acid content of edible insects is compared with well-known protein sources to demonstrate that edible insects have the potential to cover the protein quality requirements for different groups of the population. Then the current methodologies for insect protein extraction are summarized including a comparison of the protein extraction yield and the final protein content of the resulting products for each method. Furthermore, in order to improve our understanding of insect proteins, their functional properties (such as solubility, foaming capacity, emulsifying, gelation, water holding capacity and oil holding capacity) are discussed. Bioactive peptides can be released according to various enzymatic hydrolysis protocols. In this context, the bioactive properties of insect peptides (antihypertensive, antidiabetic, antioxidant and anti-inflammatory properties) have been discussed. However, the allergens present in insect proteins are still a major concern and an unsolved issue for insect-based product consumption; thus, an analysis of cross reactivity and the different methods available to reduce allergenicity are proposed. Diverse studies of insect protein hydrolysates/peptides have been ultimately promoting the utilization of insect proteins for future perspectives and the emerging processing technologies to enhance the wider utilization of insect proteins for different purposes
Protein Hydrolysates and Bioactive Peptides as Mediators of Blood Glucose—A Systematic Review and Meta-Analysis of Acute and Long-Term Studies
Type 2 diabetes mellitus (T2DM) is a major public health concern associated with high mortality and reduced life expectancy. Since diabetes is closely linked with lifestyle, not surprisingly, nutritional intervention and increased physical activity could play a vital role in attenuating the problems related to diabetes. Protein hydrolysates (PHs) and their bioactive peptides (BP) have been shown to exert a wide range of biological effects, including antioxidative, antihypertensive, and in particular, hypoglycaemic activities. To better understand the efficacy of such interventions, a systematic review and meta-analysis of randomised controlled trials (RCTs) were performed concerning the influence of protein hydrolysates on glycaemic biomarkers in subjects with and without hyperglycaemia. Five different databases were used to search for RCTs. In total, 37 RCTs were included in the systematic review and 29 RCTs in the meta-analysis. The meta-analysis revealed a significant reduction in postprandial blood glucose response (PPGR) in normoglycaemic (−0.22 mmol/L; 95% CI −0.43, −0.01; p ≤ 0.05) and in hyperglycaemic adults (−0.88 mmol/L; 95% CI −1.37, −0.39; p ≤ 0.001) compared with the respective control groups. A meta-regression analysis revealed a dose-dependent response for PPGR following PH consumption in normoglycaemic adults, specifically for doses ≤ 30 g. The postprandial blood insulin responses (PPIR) were significantly higher after the ingestion of PHs in both the group with and the group without hyperglycaemia, respectively (23.05 mIU/L; 95% CI 7.53, 38.57; p ≤ 0.01 and 12.57 mIU/L; 95% CI 2.72, 22.41; p ≤ 0.01), compared with controls. In terms of long-term responses, there was a small but significant reduction in both fasting blood glucose (FBG) and fasting glycated haemoglobin (HbA1c) in response to PH compared with the control group (p < 0.05). The PHs significantly improved the parameters of glycaemia in adults and, hence, it may contribute to the management and regulation of the future risk of developing T2DM
Composition, characterisation and emulsifying properties of natural nanoparticles in chickpea aquafaba for the formation of chilli oleoresin-in-water Pickering emulsions
This study aims to assess the compositional characteristics of British Kabuli chickpea aquafaba (AF) by conducting a comprehensive analysis from raw chickpeas to centrifugation fractions of AF and its potential use in forming and stabilising capsaicin-loaded O/W Pickering systems by exploiting the presence of self-assembled nanoparticles and proteins, which act as natural-coating agent. To this end, chickpeas were soaked (16 h, 4 °C, 1:4 chickpea: water) and pressure-cooked (20 min, 113 °C, 10 psig, 1:5 chickpea: water). The dry weight-based (DWB) compositions included total carbohydrate (76.33 ± 4.20%), protein (16.29 ± 0.43%), total phenolics (7.05–8.77 mg/g) and saponins (39.95 ± 0.89 mg/g), thus confirming the leaching of these components from seeds to AF. SDS-PAGE electrophoresis analysis revealed the presence of low MW proteins (≤∼16 kDa). The monosaccharides comprised d-glucose, d-galactose, l-arabinose, d-xylose and d-fructose. AF's particle size distribution revealed the occurrence of a bimodal population of nanoparticles (Dh ≤∼1000 nm and Dh ≤∼100 nm), further characterised by SAXS and TEM imaging. O/W emulsions were prepared with three chilli oleoresin types (capsicum, chilli birds' eye, and chilli ancho) by high-pressure homogenisation. The emulsion with the highest capsaicin content (capsicum oleoresin) was the most stable while the emulsion with the lowest capsaicin content (chilli ancho oleoresin) was the least stable. The presence of incidental nanoparticles and denatured proteins in AF was reasoned to account for the formation and stabilisation of chilli oleoresin-in-water Pickering emulsions, a newly offered explanation for its interfacial properties that will be pursued further in future studies
Effect of protein extraction and fractionation of chia seeds grown in different locations: Nutritional, antinutritional and protein quality assessment
Chia (Salvia hispanica) has become increasingly popular in recent years due to its high protein content, among other nutritional benefits. This study aims to evaluate the nutritional and antinutritional composition, protein profile and protein quality of two chia seeds grown in Mexico and the UK, as well as to assess the impact that occurs during protein extraction and fractionation. Protein content of chia samples showed an increase after degumming, defatting, and extraction, obtaining protein concentrates from Mexican (MPC) and British (BPC) chia seeds with 88.32 and 89.20 g/100 g dw, respectively. Main protein fractions found in both chia seeds were globulins (Glo) and albumins (Alb). Essential amino acid index (EAAI) of chia samples ranged between 189.40 and 496.73% showing a 2-fold increase in comparison to the reference protein. In vitro protein digestibility (IVPD) increased after protein extraction (91% for MPC and BPC) but decreased after fractionation (∼68%). Trypsin inhibitors increased 78–82% after protein extraction, while total phenolics content (TPC) increased 7.77- and 5.76-fold for Mexican albumins (MAlb) and British albumins (BAlb), respectively. Phytic acid content showed a reduction of > 90% after extraction/fractionation. These findings showed that depending on the extraction and/or fractionation methods used the protein quality, digestibility and antinutrients will be highly influenced
Implementation and analysis of list mode algorithm using tubes of response on a dedicated brain and breast PET
In this work we present an innovative algorithm for the reconstruction of PET images based on the List-Mode (LM) technique which improves their spatial resolution compared to results obtained with current MLEM algorithms. This study appears as a part of a large project with the aim of improving diagnosis in early Alzheimer disease stages by means of a newly developed hybrid PET-MR insert. At the present, Alzheimer is the most relevant neurodegenerative disease and the best way to apply an effective treatment is its early diagnosis. The PET device will consist of several monolithic LYSO crystals coupled to SiPM detectors. Monolithic crystals can reduce scanner costs with the advantage to enable implementation of very small virtual pixels in their geometry. This is especially useful for LM reconstruction algorithms, since they do not need a pre-calculated system matrix. We have developed an LM algorithm which has been initially tested with a large aperture (186 mm) breast PET system. Such an algorithm instead of using the common lines of response, incorporates a novel calculation of tubes of response. The new approach improves the volumetric spatial resolution about a factor 2 at the border of the field of view when compared with traditionally used MLEM algorithm. Moreover, it has also shown to decrease the image noise, thus increasing the image quality. © 2012 Elsevier B.V. All rights reserved.This work was supported by the Centre for Industrial Technological Development co-funded by FEDER through the Technology Fund (DREAM Project, IDI-20110718), by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) under Grant. No. FIS2010-21216-CO2-01TEO 2008/114.Moliner Martínez, L.; Correcher, C.; González Martínez, AJ.; Conde Castellanos, PE.; Hernández Hernández, L.; Orero Palomares, A.; Rodríguez Álvarez, MJ.... (2013). Implementation and analysis of list mode algorithm using tubes of response on a dedicated brain and breast PET. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 702:129-132. https://doi.org/10.1016/j.nima.2012.08.029S12913270
Monolithic crystals for PET devices: optical coupling optimization
NOTICE: this is the author’s version of a work that was accepted for publication in Nuclear Instruments and Methods in Physics Research Section A. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Nuclear Instruments and Methods in Physics Research Section A [Volume 731, 11 December 2013, Pages 288–294]
DOI 10.1016/j.nima.2013.05.049[EN] In this work we present a method to efficiently collect scintillation light when using monolithic
scintillator crystals. The acceptance angle of the scintillation light has been reduced by means of optical
devices reducing the border effect which typically affects continuous crystals. We have applied this
procedure on gamma detectors for PET systems using both position sensitive PMTs and arrays of SiPMs.
In the case of using SiPMs, this approach also helps to reduce the photosensor active area.
We evaluated the method using PMTs with a variety of different crystals with thicknesses ranging
from 10 to 24 mm. We found that our design allows the use of crystal blocks with a thickness of up to
18 mm without degrading the spatial resolution caused by edge effects and without a significant
detriment to the energy resolution. These results were compared with simulated data. The first results of
monolithic LYSO crystals coupled to an array of 256 SiPMs by means of individual optical light guides are
also presented.This work was supported by the Centre for Industrial Technological Development co-funded by FEDER through the Technology Fund (DREAM Project, IDI-20110718), the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D +I) under Grant no. FIS2010-21216-CO2-01 and the Valencian Local Government under Grant PROMETEO 2008/114.González Martínez, AJ.; Peiró, A.; Conde, P.; Hernández Hernández, L.; Moliner Martínez, L.; Orero Palomares, A.; Rodríguez-Álvarez, M.... (2013). Monolithic crystals for PET devices: optical coupling optimization. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 731:288-294. https://doi.org/10.1016/j.nima.2013.05.049S28829473
Design of the PET–MR system for head imaging of the DREAM Project
NOTICE: this is the author’s version of a work that was accepted for publication in Nuclear Instruments and Methods in Physics Research Section A. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Nuclear Instruments and Methods in Physics Research Section A, Volume 702, 21 February 2013, Pages 94–97
DOI 10.1016/j.nima.2012.08.028In this paper we describe the overall design of a PET–MR system for head imaging within the
framework of the DREAM Project as well as the first detector module tests. The PET system design
consists of 4 rings of 16 detector modules each and it is expected to be integrated in a head dedicated
radio frequency coil of an MR scanner.
The PET modules are based on monolithic LYSO crystals coupled by means of optical devices to an
array of 256 Silicon Photomultipliers. These types of crystals allow to preserve the scintillation light
distribution and, thus, to recover the exact photon impact position with the proper characterization of
such a distribution. Every module contains 4 Application Specific Integrated Circuits (ASICs) which
return detailed information of several light statistical momenta. The preliminary tests carried out on
this design and controlled by means of ASICs have shown promising results towards the suitability of
hybrid PET–MR systems.This work was supported by the Centre for Industrial Technological Development co-funded by FEDER through the Technology Fund (DREAM Project, IDI-20110718), the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I + D + I) under Grant no. FIS2010-21216-CO2-01 and the Valencian Local Government under Grant PROMETEO 2008/114.González Martínez, AJ.; Conde, P.; Hernández Hernández, L.; Herrero Bosch, V.; Moliner Martínez, L.; Monzó Ferrer, JM.; Orero Palomares, A.... (2013). Design of the PET–MR system for head imaging of the DREAM Project. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 702:94-97. https://doi.org/10.1016/j.nima.2012.08.028S949770
Consenso colombiano de atención, diagnóstico y manejo de la infección por SARS-COV-2/COVID-19 en establecimientos de atención de la salud Recomendaciones basadas en consenso de expertos e informadas en la evidencia
The “Asociación Colombiana de Infectología” (ACIN) and the “Instituto de Evaluación de Nuevas Tecnologías de la Salud” (IETS) created a task force to develop recommendations for Covid 19 health care diagnosis, management and treatment informed, and based, on evidence. Theses reccomendations are addressed to the health personnel on the Colombian context of health services. © 2020 Asociacion Colombiana de Infectologia. All rights reserved
Desenvolvimento de um roteiro conceitual para a gestão da biodiversidade e dos serviços ecossistêmicos no Caribe mexicano
Coral reefs and mangroves support rich biodiversity and provide ecosystem services that range from food, recreational benefits and coastal protection services, among others. They are one of the most threatened ecosystems by urbanization processes. In this context, we developed a conceptual framework for the management of biodiversity and ecosystem services for these coastal environments. We based our workflow on two sections: “Information base” and “Governance” and use the Puerto Morelos Coastal region as a case study for coastal protection. Puerto Morelos is between two of the most touristic destinations of Mexico (Playa del Carmen and Cancun) that has experienced an increase of population in the past four decades resulting in an intensification of multiple threats to its ecosystems. We characterized the two ecosystems with a “Management Units” strategy. An expert-based ecosystem services matrix was also described in order to connect mangroves and coral reef ecosystems with the multiple beneficiaries. Then an ecosystem model (conceptual model and Global Biodiversity model) was developed. The conceptual model was useful in understanding the interplay processes between systems regarding the ecosystem service of “Coastal Protection”. The Global Biodiversity model evidenced the human-induced shifts in the biodiversity for mangrove and coral reefs ecosystems. Also, a projection for 2035 of “best” and “worst” scenarios was applied using GLOBIO3. A DPSIR conceptual framework was used to analyze environmental problems regarding ecosystem services maintenance. Finally, we evaluated a set of policies associated with these ecosystems that favor coastal protection integrity. This framework facilitates the identification of the most relevant processes and controls about the provision of coastal protection service. It can also be useful to better target management actions and as a tool to identify future management needs to tackle the challenges preventing more effective conservation of coastal environments.Recifes de coral e manguezais possuem rica biodiversidade e fornecem serviços ecossistêmicos, tais como, alimento, recreação, proteção costeira, entre outros. Esses ecossistemas encontram-se entre os mais ameaçados pelos processos de urbanização. Nesse contexto, desenvolvemos um roteiro conceitual para a gestão da biodiversidade e dos serviços ecossistêmicos desses ambientes costeiros. Organizamos nossa sequência de passos de trabalho em duas seções: “Base de informações” e “Governança” e usamos a região costeira da cidade de Puerto Morelos (México) como um estudo de caso para analisar o serviço de proteção de costa. Puerto Morelos encontra-se entre dois dos destinos mais turísticos do México (Playa del Carmen e Cancún), e portanto sua população vem aumentando nas últimas quatro décadas, resultando na intensificação de múltiplas ameaças para os ecossistemas. Primeiramente, caracterizamos os dois ecossistemas identificando-os como “Unidades de Gestão”, detalhando seus principais componentes e processos. Através de uma “Matriz de serviços ecossistêmicos”, construída com base na opinião de especialistas, foram sistematizados os principais serviços ecossistêmicos prestados pelos manguezais e recifes de corais aos múltiplos beneficiários. Em seguida, foi desenvolvida uma modelagem do sistema (e ecossistemas) através de sua representação na forma de um modelo conceitual e um modelo numérico de Biodiversidade Global. O modelo conceitual facilitou a compreensão dos processos de interação entre sistemas em relação ao serviço “Proteção Costeira”. O modelo numérico evidenciou as mudanças induzidas pelo homem na biodiversidade dos ecossistemas de manguezal e recifes de coral. Além disso, uma projeção dos cenários “melhor” e “pior” foi desenvolvida para 2035 usando GLOBIO3. A Estrutura conceitual DPSIR foi aplicada para analisar problemas ambientais relacionados à manutenção dos serviços ecossistêmicos. Finalmente, avaliamos um conjunto de políticas públicas associadas a esses ecossistemas e que favorecem a integridade da proteção costeira. Portanto, o roteiro facilitou a identificação dos principais processos e controles para a provisão de um serviço ecossistêmico. Além disso, pode ser útil para direcionar melhor as ações de gerenciamento, bem como, uma ferramenta para identificar necessidades futuras de planejamento e gestão para enfrentar desafios que permitam uma conservação mais eficaz dos ambientes costeiros.Fil: Sánchez Quinto, Andrés. Universidad Nacional Autónoma de México; MéxicoFil: Costa, Julliet Correa da. Universidade Federal de Santa Catarina; BrasilFil: Zamboni, Nadia Selene. Universidade Federal do Rio Grande do Norte; BrasilFil: Sanches, Fábio H. C.. Universidade Federal de Sao Paulo; BrasilFil: Principe, Silas C.. Universidade de Sao Paulo; BrasilFil: Viotto, Evangelina del Valle. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Casagranda, Maria Elvira. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Lima, Francisco A. da Veiga. Universidade Federal de Santa Catarina; BrasilFil: Possamai, Bianca. Universidade Federal Do Rio Grande.; BrasilFil: Faroni Perez, Larisse. Universidade Federal de Juiz de Fora; Brasi
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