662 research outputs found
The implications of nitrogen on the fermentative growth extension of Saccharomyces cerevisiae by isoproturon
The peptone is used to provide nitrogen to Saccharomyces cerevisiae, which is an essential element for growth.
In nature and in industrial musts, essential nutrients for yeast growth are available in complex and variable flux.
Some of these compounds are herbicides, where some specific microorganisms are capable to mineralize or
degrade into more basic and less harmful compounds to the environmental. The isoproturon (IPU), a phenylurea
used as an herbicide, is a compound very difficult to degrade in soils and aquifers, reaching levels considered
toxic by European legislation, contributing to both surface and ground water pollution, and it may be also
involved in the triggering of serious illnesses. So, it’s urgent to discover biological models to contribute to
degrade or eliminate phenylureas in situations of accidental or systematic contamination.
The main target of this study was to evaluate the influence of nitrogen to extend the fermentative phase of S.
cerevisiae by IPU, using the wild-type strain UE-ME3 deposited in the collection of Enology Laboratory of
University of Évora, Portugal.
Cells at mid-exponential phase were inoculated in presence of 100μM IPU in YEPD or YED medium and
incubated during 72 h with orbital stirring, at 28 ºC. Samples from each treatment were used to obtain OD, cfu,
dry weight and to prepare post-12000 g supernatant for determination of protein [1], glutathione (GSH,GSSG)
[2] and malondialdehyde (MDA) [3] contents, and cell capacity to scavenge free radicals by the 2,2-diphenyl-1-
picryl-hidrazil (DPPH) [4] method, as well as, enzyme activities catalase T (CAT T) [5], glutathione reductase
(GR) [6], glutathione peroxidase (GPx) [7], glucose-6-phosphate dehydrogenase (G6PD) [8], alcohol
dehydrogenase (ADH) [9], malate dehydrogenase (MDH2) [10] and lactate dehydrogenase (LDH) [11] by
fluorescence and spectrophotometry. The post-12000 g pellet was also used for protein content and enzyme
activity catalase A (CAT A) determination.
The results show that yeast grown in presence of IPU in peptone starvation conditions (YED-IPU) exhibit at 72 h
a differential growth profile, with cfu, OD, dry weight and level of protein lower than cells grown in YEPD-IPU.
The same type of response was detected in terms of antioxidant power estimated by the GSH/GSSG ratio and
ability to scavenge free radicals detected by DPPH, as well as the levels of enzyme activities CAT T, CAT A,
GR and G6PD which appears much lower in yeast cells grown in YED-IPU medium. On the other hand, cells
exposed to IPU in YEPD medium exhibited fermentative activities, ADH and LDH, higher than those detected in
cells exposed to phenylurea in the restrictive nitrogen medium, YED-IPU. This set of results suggests that yeast
grown in rich medium, YEPD-IPU, remained more fermentative than those grew up in restrictive YED-IPU
medium. This interpretation maybe confirmed by higher levels of glutathione and MDA contents, as well as
enzyme activities GPx and MDH2 detected in S. cerevisiae exposed to YEPD-IPU which started early the
respiratory-fermentative transition. So, S. cerevisiae grown in the nitrogen starvation conditions may more easily
recognize isoproturon as substrate and expand its fermentative phase
Optimizing the profit from a complex cascade of hydroelectric stations with recirculating water
In modern reversible hydroelectric power stations it is possible to reverse the turbine and pump water up from a downstream reservoir to an upstream one. This allows the use of the same volume of water repeatedly and was speci cally developed for hydro-electric stations operating with in-
su cient water supply. Pumping water upstream is usually done at times of
low demand for electricity, to build up reserves in order to be able to produce
energy during peak hours, thus balancing the load and making a pro t on the price di erence.
In this paper, we consider a branched model for hydroelectric power stations interacting in a complex cascade arrangement. The goal of this study is to provide guidance in decision-making aimed at maximizing the pro t. A detailed analysis is made of a simpler reservoir con guration, which indicates
that even though the problem is nonlinear, a bang-bang type of control is optimal, where the power stations are operated at maximum rates of flow.
Some simple relationships between price and timing of decisions are calculated directly. A numerical algorithm is also developed.This problem was brought by Redes Energéticas Nacionais to the 69th European Study Group with Industry, April 20–24, 2009, Departamento de Matemática da Universidade de Coimbra, Portugal.
Andrei Korobeinikov and Mark McGuinness are very grateful to the organizers of the 69th ESGI for financial support and for their kind and generous hospitality. Andrei Korobeinikov and Mark McGuinness are supported by the Mathematics Applications132 Optimizing the profit from a complex cascade of hydroelectric stations with recirculating water Consortium for Science and Industry, funded by the Science Foundation Ireland Mathematics Initiative Grant 06/MI/005. Mark McGuinness also thanks OCCAM in Oxford for supporting his travels.
Marta Pascoal is partially funded by the Portuguese FCT under project POSC/U308/1.3/NRE/04
Preliminary Analysis of the Portuguese Version of the Child Anxiety Life Interference Scale
Ultrasonication processing for the production of plant-based nanoemulsions
Plant-derived proteins have been emerging and growing in interest over the past few years, due to their interesting
properties and the trend to replace animal-derived proteins [1]. Ultrasonication processing can be used to develop
nanoemulsions based on plant proteins that are kinetically stabilized by their small dimension, unlike classic emulsions [2].
In this work, oil-in-water nanoemulsions were produced through high-speed homogenization, followed by ultrasonic
homogenization (US), using different plant-derived proteins, including potato (Solanum tuberosum), lupin (Lupinus
angustifolius), pea (Pisum sativum), chickpea (Cicer arietinum) and faba bean (Vicia faba) protein as emulsifiers. A central
composite rotatable experimental design was used to evaluate the influence of three independent variables: water/oil
ratio (65-75% of water), protein content (1-6%) and US time (1-7 min) on the size average (by intensity) and polydispersity
index (PDI) of the nanoemulsions. A total of 17 experiments were performed with 14 three-level experimental points, and
3 replicates at the central point. The effect of the US time (0, 3, 4.5 and 6 min) in the potato and lupin proteins primary
and secondary structures were analysed through SDS-PAGE electrophoresis and circular dichroism, respectively.
Results showed that the use of potato, lupin and pea proteins lead to the formation of stable nanoemulsions, while
chickpea and faba bean proteins resulted in non-stable nanoemulsions, with phase separation.
The smallest mean droplet size for potato protein was 439.9 nm and PDI value 0.464 [21:73 (w/w) oil/water ratio, 6% of
protein and 6 min of US]. The smallest mean droplet size for lupin protein was 505.5 nm and PDI value 0.434, and for pea
protein the droplet size was 551.3 nm and PDI value 0.249 [23.6:73 (w/w) oil/water ratio, 3.4% of protein and 6 min of US].
Electrophoresis results show that for native potato and lupin samples the ultrasonication did not induce significant
changes in the protein pattern, indicating that the US treatment did not modify the primary structure. Regarding the
second structure, US did not change the secondary structure of potato protein but induced a slight increase of -helix for
all US treatments for lupin protein.
Stable nanoemulsions can be developed using plant-derived proteins and ultrasonication, foreseeing different
applications in the food industry.This study was supported by the project cLabel+ (POCI-01-0247-FEDER-046080) cofinanced by Compete 2020, Lisbon
2020, Portugal 2020 and the European Union, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio
Bridging intravenous thrombolysis in patients with atrial fibrillation.
Background and purpose
40% of acute ischemic stroke patients treated by mechanical thrombectomy (MT) have a clinical history of atrial fibrillation (AF). The safety of bridging intravenous thrombolysis (IVT) (MT + IVT) is currently being discussed. We aimed to analyze the interaction between oral anticoagulation (OAC) status or AF with bridging IVT, regarding the occurrence of symptomatic intracranial hemorrhage (sICH) and functional outcome.
Materials and Methods
Multicentric observational cohort study (BEYOND-SWIFT registry) of consecutive patients undergoing MT between 2010 and 2018 (n = 2,941). Multinomial regression models were adjusted for prespecified baseline and plausible pathophysiological covariates identified on a univariate analysis to assess the association of AF and OAC status with sICH and good outcomes (90-day modified Rankin Scale score 0-2).
Results
In the total cohort (median age 74, 50.6% women), 1,347 (45.8%) patients had AF. Higher admission National Institutes of Health Stroke Scale (NIHSS) score (aOR 1.04 [95% 1.02-1.06], per point of increase) and prior medication with Vitamin K antagonists (VKA) (aOR 2.19 [95% 1.27-3.66]) were associated with sICH. Neither AF itself (aOR 0.71 [95% 0.41-1.24]) nor bridging IVT (aOR 1.08 [0.67-1.75]) were significantly associated with increased sICH. Receiving bridging IVT (aOR 1.61 [95% 1.24-2.11]) was associated with good 90-day outcome, with no interaction between AF and IVT (p = 0.92).
Conclusion
Bridging IVT appears to be a reasonable clinical option in selected patients with AF. Given the increased sICH risk in patients with VKA, subgroup analysis of the randomized controlled trials should analyze whether patients with VKA might benefit from withholding bridging IVT.
Registration
clinicaltrials.gov; Unique identifier: NCT03496064
HDAC-6 inhibition ameliorates the early neuropathology in a mouse model of Krabbe disease
IntroductionIn Krabbe disease (KD), mutations in β-galactosylceramidase (GALC), a lysosomal enzyme responsible for the catabolism of galactolipids, leads to the accumulation of its substrates galactocerebroside and psychosine. This neurologic condition is characterized by a severe and progressive demyelination together with neuron-autonomous defects and degeneration. Twitcher mice mimic the infantile form of KD, which is the most common form of the human disease. The Twitcher CNS and PNS present demyelination, axonal loss and neuronal defects including decreased levels of acetylated tubulin, decreased microtubule stability and impaired axonal transport.MethodsWe tested whether inhibiting the α-tubulin deacetylase HDAC6 with a specific inhibitor, ACY-738, was able to counteract the early neuropathology and neuronal defects of Twitcher mice.ResultsOur data show that delivery of ACY-738 corrects the low levels of acetylated tubulin in the Twitcher nervous system. Furthermore, it reverts the loss myelinated axons in the sciatic nerve and in the optic nerve when administered from birth to postnatal day 9, suggesting that the drug holds neuroprotective properties. The extended delivery of ACY-738 to Twitcher mice delayed axonal degeneration in the CNS and ameliorated the general presentation of the disease. ACY-738 was effective in rescuing neuronal defects of Twitcher neurons, stabilizing microtubule dynamics and increasing the axonal transport of mitochondria.DiscussionOverall, our results support that ACY-738 has a neuroprotective effect in KD and should be considered as an add-on therapy combined with strategies targeting metabolic correction
SMART-QUAL: a dashboard for quality measurement in higher education institutions
Purpose – The paper aims to define a dashboard of indicators to assess the quality performance of higher education institutions (HEI). The instrument is termed SMART-QUAL.
Design/methodology/approach –Two sources were used in order to explore potential indicators. In the first step, information disclosed in official websites or institutional documentation of 36 selected HEIs was analyzed. This first step also included in depth structured high managers’ interviews. A total of 223 indicators emerged. In a second step, recent specialized literature was revised searching for indicators, capturing additional 302 indicators.
Findings – Each one of the 525 total indicators was classified according to some attributes and distributed
into 94 intermediate groups. These groups feed a debugging, prioritization and selection process, which
ended up in the SMART-QUAL instrument: a set of 56 key performance indicators, which are grouped in 15
standards, and, in turn, classified into the 3 HEI missions. A basic model and an extended model are also
proposed.
Originality/value – The paper provides a useful measure of quality performance of HEIs, showing a holistic
view to monitor HEI quality from three fundamental missions. This instrument might assist HEI managers for
both assessing and benchmarking purposes. The paper ends with recommendations for university managers
and public administration authorities
Global hyperactivation of enhancers stabilizes human and mouse naïve pluripotency through inhibition of CDK8/19 Mediator kinases
Pluripotent stem cells (PSCs) transition between cell states in vitro and reflect developmental changes in the early embryo. PSCs can be stabilized in the naïve state by blocking extracellular differentiation stimuli, particularly FGF-MEK signaling. Here, we report that multiple features of the naïve state in human and mouse PSCs can be recapitulated without affecting FGF-MEK-signaling or global DNA methylation. Mechanistically, chemical inhibition of CDK8 and CDK19 kinases removes their ability to repress the Mediator complex at enhancers. Thus CDK8/19 inhibition increases Mediator-driven recruitment of RNA Pol II to promoters and enhancers. This efficiently stabilizes the naïve transcriptional program and confers resistance to enhancer perturbation by BRD4 inhibition.
Moreover, naïve pluripotency during embryonic development coincides with a reduction in CDK8/19. We conclude that global hyperactivation of enhancers drives naïve pluripotency, and this can be achieved in vitro by inhibiting CDK8/19 kinase activity. These principles may apply to other contexts of cellular plasticity
Caracterização e avaliação sensorial de barra de cereal com extrato de antocianinas da fruta da palmeira jussara (euterpe edulis) / Characterization and sensorial evaluation of cereal bar with anthocyanins extract from the fruit of palmeira jussara (euterpe edulis)
Foram desenvolvidas três formulações de barras de cereais com alto teor de fibra a base de aveia (Avena sativa L). Na formulação considerada a mais adequada (12,7% de fibras (m/m)) adicionou-se extrato de antocianina de frutos da palmeira Jussara (Euterpe edulis Martius) na concentração de 0; 0,25; 1.0; 2,0% (m/m). O teor de antocianinas no extrato foi obtido pelo método diferencial de pH. A composição centesimal das barras de cereais foi realizada e a atividade antioxidante, no extrato antocianínico e nas barras de cereais, foi determinada pelo método de captura de radicais livres. Foi realizado teste afetivo de aceitabilidade para verificar qual a barra de cereal de maior aceitação. As barras de cereais apresentaram teor de umidade, 11,1-12,2% (m/m); cinzas, 1,3-2,3% (m/m); lipídeos, 4,4-6,0% (m/m); proteínas, 4,2-6,0% (m/m); fibra alimentar, 12,7-15,1% (m/m); carboidratos, 58,3-64,5% (m/m); e valor energético de 78,4-82,2 kcal / bar. O conteúdo de antocianina no extrato seco foi de 17,64 ± 1,13 mg de antocianina/100g de fruta e a atividade antioxidante foi de cerca de 90% na concentração de 0,5 mg ml-1. As barras de cereais apresentaram atividade antioxidante de 74,7; 87,8; e 86,6 com adição de 0,25; 1.0; e 2,0% de extrato, respectivamente, indicando boa capacidade antioxidante. A barra de cereais desenvolvida contendo extrato de antocianina a 2,0% (p/p) foi considerada a mais adequada após análise sensorial
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