4,902 research outputs found
Análise da variabilidade do IRI obtido por vários perfilómetros
A irregularidade longitudinal, caracterizada habitualmente pelo Índice Internacional de
Irregularidade (IRI – International Roughness Index), é um dos parâmetros de estado
dos pavimentos rodoviários cuja variabilidade pode ter consequências relevantes nas
estratégias de reabilitação e, consequentemente, nos custos e na sua vida de serviço. Por
esta razão, este artigo tem por principal objectivo proporcionar às entidades referidas
informação útil no que respeita à variabilidade do IRI, calculado a partir de dados
obtidos por vários perfilómetros. Assim, foram seleccionados cinco veículos do
tipo”multifunções”, que pertencem quer a empresas de consultadoria quer a instituições
de investigação, e três trechos de estrada com camadas de desgaste em betão
betuminoso drenante, betão betuminosos rugoso e betão betuminoso “convencional”.
Cada veículo percorreu cinco vezes cada trecho nos dois sentidos de tráfego. O
espaçamento adoptado para o cálculo do IRI foi de 100 m. A média e o desvio padrão
foram os parâmetros usados para estudar a variabilidade dos resultados. De uma forma
geral verificou-se que o valor do desvio padrão do IRI é 20 a 30% do valor da média
Stability of Fried Olive and Sunflower Oils Enriched with Thymbra capitata Essential Oil
The stability of olive and sunflower oils for domestic uses after frying cow steak or only heating were evaluated in the presence or absence of the carvacrol-rich essential oil of Thymbra capitata. The treatments consisted of sunflower and olive oils either enriched with 200 mg/l of T. capitata oil or without it, heating at 180°C for 20 min, or frying 100 g cow steak at the same temperature and for the same period of time. In all assays, acid, peroxide, and p-anisidine values were followed over time. The fatty acid profile was estimated before heating or frying as well as at the end of the experiment. The results showed that the type of fat as well as the type of treatment (frying or heating) was determinant for the acid, peroxide, and p-anisidine values found. The presence of the essential oil also demonstrated to affect those values depending on the type of the oil as well as on the type of the treatment (frying or heating). In contrast, the fatty acid profile did not change greatly
The effect of a remifentanil bolus on the bispectral index of the EEG (BIS) in anaesthetized patients independently from intubation and surgical stimuli
Background and objective: Remifentanil boluses are used in different clinical situations and the effects on bispectral index monitoring are unclear. We analysed the effect of a remifentanil bolus on the bispectral index of the electroencephalogram (bispectral index) under total intravenous anaesthesia with propofol and remifentanil.
Methods: ASA I–III patients were included in this study. All patients received a 2 µg kg 1 remifentanil bolus
in a period free from stimuli. Bispectral index and haemodynamic data were collected from an A-2000XP bispectral index monitor (every second) and an AS/3 Datex monitor (every 5 s). Bispectral index data were analysed
using the area under the curve. Mean arterial pressure and heart rate were averaged at each 30-s period and
analysed using analysis of variance. Results: A total of 240 bispectral index values were obtained per patient.
The area under the curve between 90 and 120 s after the bolus was significantly lower than the basal area under
the curve (average of all areas before the bolus, P 0.05). Mean arterial pressure and heart rate were significantly reduced from 96.4 19.9 mmHg at the time of the bolus to 74.2 16.6 mmHg 120 s after, and from
70 16.4 bpm at the time of the bolus to 61 13.6 bpm after (P 0.001), respectively. Conclusions: There was a
significant reduction in the areas under the curve between 90–120 s following the bolus. Heart rate and blood pressure also showed significant reductions. Thus, remifentanil bolus given under total intravenous anaesthesia with
propofol and remifentanil decreases bispectral index, an effect independent of intubation and surgical stimuli.info:eu-repo/semantics/publishedVersio
Characterization of a spirit beverage produced with strawberry tree (Arbutus unedo L.) fruit and aged with oak wood at laboratorial scale
Arbutus unedo spirit is a valuable product in Mediterranean countries. This spirit is usually
marketed in Portugal without wood ageing. This work aims to characterize the ageing effect on the
Arbutus unedo spirit, for three and six months with oak wood (Quercus robur L.) submitted to different
toasting levels, based on its chemical composition and its sensory properties. For this purpose,
several parameters were analysed: acidity, pH, dry extract, and volatile compounds (methanol,
acetaldehyde, ethyl acetate and fusel alcohols). The volatile compounds were identified by GC-MS
and quantified by GC-FID. Sensory analysis was performed by a trained panel, who have profiled
this beverage, as well as the changes acquired during ageing. Spectroscopic techniques, namely
FTIR–ATR, were applied to discriminate the different beverages produced. The results highlighted
an increase in Arbutus unedo spirit’s quality with the wood contact, mainly based on the sensory
attributes. Additionally, they showed that the best beverages were produced using oak wood with
medium toasting levels during three months of ageinginfo:eu-repo/semantics/publishedVersio
Antioxidant activity of thymbra capitata essential oil in meat-treated oil
Several synthetic antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tertiary butyl hydroquinone (TBHQ), have been used to preserve meat. Nevertheless they are considered toxic and to have carcinogenic effects. Natural products, such as those present in essential oils, have been the target of studies as alternative antioxidants, showing promising results. In addition, these natural compounds have the advantage of having consumer's acceptance. Thymbra capitata is a perennial, herbaceous shrub commonly used as a spicy herb. The essential oils isolated from this plant showed antimicrobial and antioxidant activities. The main goal of the present work was to evaluate the capacity of T. capitata oil to prevent lipid oxidation in bovine meat. Different concentrations of essential oil (0, 50, 75 and 100 mg/5 g of meat) were used in two types of bovine meat samples purchased in the local market. The protein content of both types of meat samples was 21%, and lipid content ranged from 9% to 15%. After covering with the oil, the two types of meat samples were stored at -17 degrees C, for one month. After 1 day, 15 days and 30 days, meat samples were taken and cooked at 85 degrees C for 90 min. The samples were then submitted to the TBARS modified method, for antioxidant activity evaluation. The essential oil was able to prevent meat oxidation even after one month of storage and showed a dose-dependent activity
Activation pathway to amino acid adducts
Funding: This work was supported in part by Fundação para a Ciência e a Tecnologia (FCT), Portugal (PTDC/QUI-QUI/113910/2009, RECI/QEQ-MED/0330/2012, UID/QUI/00100/2013 and IF/ 01091/2013/CP1163/CT0001), and by Interagency Agreement Y1ES1027 between the National Center for Toxicological Research/Food and Drug Administration and the National Institute of Environmental Health Sciences/National Toxicology Program. The opinions expressed in this paper do not necessarily represent those of the U.S. Food and Drug Administration. RW, ALG, ILM and SGH thank FCT for postdoctoral and doctoral fellowships (SFRH/BPD/70953/2010, SFRH/BD/72301/2010, SFRH/BD/75426/2010 and SFRH/BD/ 80690/2011, respectively). AMM also acknowledges Programa Operacional Potencial Humano from FCT and the European Social Fund (IF/01091/2013), and the LRI Innovative Science Award. We thank the Portuguese NMR and MS networks (IST nodes) for providing access to the facilities.Nevirapine (NVP) is the non-nucleoside HIV-1 reverse transcriptase inhibitor most commonly used in developing countries, both as a component of combined antiretroviral therapy and to prevent mother-to-child transmission of the virus; however, severe hepatotoxicity and serious adverse cutaneous effects raise concerns about its safety. NVP metabolism yields several phenolic derivatives conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid derivatives prone to react with bionucleophiles and initiate toxic responses. We investigated the ability of two phenolic NVP metabolites, 2-hydroxy-NVP and 3-hydroxy-NVP, to undergo oxidation and subsequent reaction with bionucleophiles. Both metabolites yielded the same ring-contraction product upon oxidation with Frémy's salt in aqueous medium. This is consistent with the formation of a 2,3-NVP-quinone intermediate, which upon stabilization by reduction was fully characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. Additionally, we established that the oxidative activation of 2-hydroxy-NVP involved the transient formation of both the quinone and a quinone-imine, whereas 3-hydroxy-NVP was selectively converted into 2,3-NVP-quinone. The oxidations of 2-hydroxy-NVP and 3-hydroxy-NVP in the presence of the model amino acids ethyl valinate (to mimic the highly reactive N-terminal valine of hemoglobin) and N-acetylcysteine were also investigated. Ethyl valinate reacted with both 2,3-NVP-quinone and NVP-quinone-imine, yielding covalent adducts. By contrast, neither 2,3-NVP-quinone nor NVP-derived quinone-imine reacted with N-acetylcysteine. The product profile observed upon Frémy's salt oxidation of 2-hydroxy-NVP in the presence of ethyl valinate was replicated with myeloperoxidase-mediated oxidation. Additionally, tyrosinase-mediated oxidations selectively yielded 2,3-NVP-quinone-derived products, while quinone-imine-derived products were obtained upon lactoperoxidase catalysis. These observations suggest that the metabolic conversion of phenolic NVP metabolites into quinoid electrophiles is biologically plausible. Moreover, the lack of reaction with sulfhydryl groups might hamper the in vivo detoxification of NVP-derived quinone and quinone-imine metabolites via glutathione conjugation. As a result, these metabolites could be available for reaction with nitrogen-based bionucleophiles (e.g., lysine residues of proteins) ultimately eliciting toxic events.publishersversionpublishe
Microarray in clinical practice – utility vs complexity. Mixed phenotype of duplication 15q11.2q13.1 and deletion 16p11.2
Introduction: There’s a consensus to perform chromosomal microarray
technique as first-tier clinical diagnostic test for individuals with developmental
disabilities. However, given the complexity of clinical presentations, often several
diagnostic methods are held before conducting microarray.
Method: We report the case of a 5 year-old boy referred to Medical Genetics due
to short stature, developmental disabilities and facial dysmorphic features.
He was born from eutocic delivery after an uneventful pregnancy. He had
psychomotor milestones delayed like sitting at 9 months and walking at 24
months, holding an immature broad-based gait. There was history of learning
difficulties from both parents, and the mother has also short stature.
On examination it was noted some facial dysmorphic features like high forehead,
conical canines and rarefaction of the distal portion of the eyebrows.
Due to the history of an episode of transient ataxia, and suspicion of an inherited
metabolic disorder, he had already performed various analytical and imaging
screenings, all normal.
Results: Chromosomal microarray analysis revealed two pathogenic Copy
Number Variants (CNV’s): 16p11.2 deletion and 15q11.2q13.1 duplication.
The 15q11q13 microduplication syndrome (OMIM # 608636) is a very rare clinical
entity with about 30 reported cases with maternal origin, and it is characterized by
neurobehavioral disorder, hypotonia, cognitive impairment, epilepsy and short
stature.
The 16p11.2 microdeletion syndrome (OMIM # 613444) is also a rare clinical
entity, with high penetrance, associated with obesity and developmental
disabilities.
Discussion: Despite the unquestionable utility of microarray, the correlation of
the CNV's with the phenotype is often difficult by the rarity of these new
microdeletion/duplication clinical entities. In this case the interpretation has
increased difficulty because of the simultaneous existence of two distinct clinical
entities. Segregation studies, which in the first step include parental analysis, are
essential for genetic counseling and determining the risk of recurrence but also
for a more accurate correlation genotype-phenotype
NIRS and multivariate methods for discrimination of morning glory species at different growth stages
Morning glory species are weeds very common in tropical crops, where they cause direct and indirect damage. The management of these species primarily relies on the application of herbicides, disregarding the growth stage and spatial distribution. Studies addressing new techniques for identifying these species may contribute to the development of proximal sensors for carrying out specific and rational management. Thus, the objective of this work was to use near infrared spectroscopy (NIRS) and multivariate analysis to discriminate two species of morning glory in three growth stages. NIRS spectra were collected from Ipomoea hederifolia and Merremia aegyptia were collected at three different stages in the spectral range of 4.000 to 10.000 cm-1. PCA and PC-LDA were used to analyze the entire spectrum and specific bands. NIRS associated with PCA and PC-LDA were sufficient to discriminate I. hederifolia and M. aegyptia species and their growth stages. PCA allowed a proper segregation of stages and species when applied individually PC-LDA correctly classified between 90.93 to 100% of species and stages. The best discrimination results were observed in the NIR spectra ranges from 4.500 to 6.000 cm-1 and 4.500 to 6.000 + 6.500 to 7.750 cm-1. This study represents an advance in the research and implementation of NIRS technology to discriminate weed species for the future development of equipment to assist in the adoption and/or performance of a specific management of weeds, capable of contributing to the reduction in the use of herbicides in crops
The future of power systems: Challenges, trends, and upcoming paradigms
The decarbonization of the economy, for which the contribution of power systems is significant, is a growing trend in Europe and in the world. In order to achieve the Paris Agreement's ambitious environmental goals, a substantial increase in the contribution of renewable sources to the energy generation mix is required. This trend brings about relevant challenges as the integration of this type of sources increases, namely in terms of the distribution system operation. In this paper, the challenges foreseen for future power systems are identified and the most effective approaches to deal with them are reviewed. The strategies include the development of Smart Grid technologies (meters, sensors, and actuators) coupled with computational intelligence that act as new sources of data, as well as the connection of distributed energy resources to distribution grids, encompassing the deployment of distributed generation and storage systems and the dissemination of electric vehicles. The impact of these changes in the distribution system as a whole is evaluated from a technical and environmental perspective. In addition, a review of management and control architectures designed for distribution systems is conducted. This article is categorized under: Energy Infrastructure > Systems and Infrastructure Energy Infrastructure > Economics and Policy.ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT - Fundacao para a Ciencia e a Tecnologia, Grant/Award Number: SAICTPAC/0004/2015-POCI-01-0145-FEDER-01643
Characterization of Soybean Cultivars for Biodiesel Production
Due to environmental issues involving the polluting gasesemission, Brazil has adopted the policy of using oil and biodiesel. For biodiesel production, the main raw material used in Brazil is soybean oil. The development of the numerous genotypes of this culture has always considered quantitative aspects. The objective was to qualitatively characterize 12 soybean cultivars for biodiesel production. The experimental design was randomized blocks with three replicates. The cultivars were sown in December 2016, in no-tillage system, in Ponta Grossa, Paraná, Brazil (-25.093056, -50.063327 UTM). The analyzed variables were: oil and protein contents, acidity index and specific mass. It was concluded that there were no significant differences among the cultivars for oil and protein contents. For the variables acidity index and specific mass, there were significant differences among the cultivars, being below the limits established by the Brazilian legislation for vegetable oil, but with potential for biodiesel production
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