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"Ribeiro, B"
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Volume of supervised exercise training impacts glycaemic control in patients with type 2 diabetes: a systematic review with meta-regression analysis
by
Ribeiro, P. A. B.
,
Schaan, B. D.
,
Ribeiro, J. P.
in
Aerobics
,
Biological and medical sciences
,
Blood Glucose - metabolism
2013
Aims/hypothesis
Supervised exercise programmes improve glycaemic control in type 2 diabetes, but training characteristics associated with reduction in HbA
1c
remain unclear. We conducted a systematic review with meta-regression analysis of randomised clinical trials (RCTs) assessing the association between intensity and volume of exercise training (aerobic, resistance or combined) and HbA
1c
changes in patients with type 2 diabetes.
Methods
Five electronic databases were searched (1980–2012) to retrieve RCTs of at least 12 weeks' duration, consisting of supervised exercise training vs no intervention, that reported HbA
1c
changes and exercise characteristics. Two independent reviewers conducted study selection and data extraction.
Results
Twenty-six RCTs (2,253 patients) met the inclusion criteria. In multivariate analysis, baseline HbA
1c
and exercise frequency explained nearly 58% of between-study variance. Baseline HbA
1c
was inversely correlated with HbA
1c
reductions after the three types of exercise training. In aerobic training, exercise volume (represented by frequency of sessions) was associated with changes in HbA
1c
(weighted
r
= −0.64), while no variables were correlated with glycaemic control induced by resistance training. In combined training, weekly volume of resistance exercise explained heterogeneity in multivariate analysis and was associated with changes in HbA
1c
levels (weighted
r
= −0.70).
Conclusions/interpretation
Reduction in HbA
1c
is associated with exercise frequency in supervised aerobic training, and with weekly volume of resistance exercise in supervised combined training. Therefore, exercise volume is a major determinant of glycaemic control in patients with type 2 diabetes.
Journal Article
Integral Valorization of Pineapple (Ananas comosus L.) By-Products through a Green Chemistry Approach towards Added Value Ingredients
by
Pastrana, Lorenzo
,
Campos, Débora A.
,
Ribeiro, Tânia B.
in
Ananas comosus
,
antioxidant activity
,
Antioxidants
2020
Industrial by-products are produced every day through fruit processing industries. Pineapple is not an exception; when processed, around 60% (w/w) of its weight are peels, stem, trimmings, and crown, the only used fruit part for human consumption. Due to high concerns of sustainability in the food system and negative high impact of human practice in the environment, a strategy has to be developed. Therefore, a green chemistry approach was applied to pineapple by-products to make an integrated valorization by the extraction of bioactive molecules. Two pineapple by-products (peels and stems) were studied, applying a green chemistry approach, which means the non-use of organic solvents or extreme methodologies. A subdivision of each by-product was done by the application of a juice machine. The peels and stems in the fresh state were ground separately, creating two fractions for each by-product—a juice and a wet pulp (press cake). The press cake was characterized, dried, and ground to create a fine powder flour. To the juice, a precipitation methodology with polysaccharides was applied, which allowed the bromelain separation (developing of an enzymatic fraction) from the fruit juice. The enzymatic extract was freeze-dried, and the juice was spray-dried, developing two more fine powders. Thus, three new ingredients were produced from each by-product, creating a total of six new ingredients. Overall, the enzymatic fractions represented around 0.26% (w/w) of pineapple weight. Pineapple stem juice represented 4.8% (w/w), and peel juice represented 17.3% (w/w). Pineapple stem flour represented 3.1% (w/w), and peel flour represented 11.4% (w/w) of the total pineapple weight. To valorize the by-products juices, a full characterization was performed of bioactive molecules and biological activities. When comparing the two juices, the peel juice showed lower content of total phenolic compounds, lower antioxidant capacity, and lower content of vitamin C. The different phenolic compounds were identified by HPLC analysis in the two pineapple by-products juices. However, the same compounds in both juices were quantified (chlorogenic, caffeic, and ferulic acids). On the other hand, the by-products flours had a high content of insoluble dietary fiber (IDF), mainly cellulose and hemicellulose. Therefore, the approach applied in this work opens the door to the production of green products, as a result of by-products valorization. This could be applied not only in the food industry but also in the nutraceutical and cosmetic industries.
Journal Article
Creation of forest edges has a global impact on forest vertebrates
2017
Forest edges influence more than half of the world’s forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200–400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-violant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.
Journal Article
Electrokinetic Remediation for Environmental Security and Sustainability
by
CENSE - Centro de Investigação em Ambiente e Sustentabilidade
,
Ribeiro, Alexandra B
,
DCEA - Departamento de Ciências e Engenharia do Ambiente
in
Chemistry(all)
,
Electrokinetic remediation
,
Environmental protection
2021
Electrokinetic Remediation for Environmental Security and Sustainability Explore this comprehensive reference on the remediation of contaminated substrates, filled with cutting-edge research and practical case studies Electrokinetic Remediation for Environmental Security and Sustainability delivers a thorough review of electrokinetic remediation (EKR) for the treatment of inorganic and organic contaminants in contaminated substrates. The book highlights recent progress and developments in EKR in the areas of resource recovery, the removal of pollutants, and environmental remediation. It also discusses the use of EKR in conjunction with nanotechnology and phytoremediation. Throughout the book, case studies are presented that involve the field implementation of EKR technologies. The book also includes discussions of enhanced electrokinetic remediation of dredged co-contaminated sediments, solar-powered bioelectrokinetics for the mitigation of contaminated agricultural soil, advanced electro-fenton for remediation of organics, electrokinetic remediation for PPCPs in contaminated substrates, and the electrokinetic remediation of agrochemicals such as organochlorine compounds. Other topics include: A thorough introduction to the modelling of electrokinetic remediation An exploration of the electrokinetic recovery of tungsten and removal of arsenic from mining secondary resources An analysis of pharmaceutically active compounds in wastewater treatment plants with a discussion of electrochemical advanced oxidation as an on-site treatment A review of rare earth elements, including general concepts and recovery techniques, like electrodialytic extraction A treatment of hydrocarbon-contaminated soil in cold climate conditions Perfect for environmental engineers and scientists, geologists, chemical engineers, biochemical engineers, and scientists working with green technology, Electrokinetic Remediation for Environmental Security and Sustainability will also earn a place in the libraries of academic and industry researchers, engineers, regulators, and policy makers with an interest in the remediation of contaminated natural resources.
Total and Sustainable Valorisation of Olive Pomace Using a Fractionation Approach
2020
Olive pomace management represents a great concern to the olive oil industry. This work focused on the development of a “zero waste” strategy for olive pomace based on a fractionation approach resulting in the obtention of different value-added fractions. The physicochemical composition of edible fractions obtained (liquid and pulp) was analysed. The potential use as a solid biofuel of the non-edible fraction (stones) was evaluated. High amounts of hydroxytyrosol (513.61–625.76 mg/100 g dry weight) were present in the liquid fraction. Pulp fraction was demonstrated to be a good source of fibre (53–59% dry weight) with considerable antioxidant activity both from free and bound phenolics. The stones fraction exhibited substantial high heating values (18.65–18.94 megajoule (MJ/kg). All these results support the added value of the olive pomace fractions combining the biofuel potential from the stones fraction and the functional food ingredients’ potential both from liquid and pulp fractions. The present methodology seems to be a feasible whole valorisation approach to achieve the circularity in the olive oil sector, prioritising obtaining high over low added-value products.
Journal Article
Galaxy distributions as fractal systems
by
Lopes, Amanda R
,
Teles, Sharon
,
Ribeiro, Marcelo B
in
Cosmology
,
Fractal analysis
,
Fractal geometry
2022
This paper discusses if large scale galaxy distribution samples containing almost one million objects can be characterized as fractal systems. The analysis performed by Teles et al. (Phys Lett B 813:136034, 2021) on the UltraVISTA DR1 survey is extended here to the SPLASH and COSMOS2015 catalogs, hence adding 750k new galaxies with measured redshifts to the studied samples. The standard ΛCDM cosmology having H0=(70±5) km/s/Mpc and number density tools required for describing these galaxy distributions as single fractal systems with dimension D are adopted. We use the luminosity distance dL, redshift distance dz and galaxy area distance (transverse comoving distance) dG as relativistic distance definitions to derive galaxy number densities in the redshift interval 0.1≤z≤4 at volume limited subsamples defined by absolute magnitudes in the K-band. Similar to the findings of Teles et al. (2021), the results show two consecutive redshift scales where galaxy distribution data behave as single fractal structures. For z<1 we found D=1.00±0.12 for the SPLASH galaxies, and D=1,39±0.19 for the COSMOS2015. For 1≤z≤4 we respectively found D=0.83-0.37+0.36 and D=0.54-0.26+0.27. These results were verified to be robust under the assumed Hubble constant uncertainty. Calculations considering blue and red galaxies subsamples in both surveys showed that the fractal dimensions of blue galaxies as basically unchanged, but the ones for the red galaxies changed mostly to smaller values, meaning that D may be seen as a more intrinsic property of the distribution of objects in the Universe, therefore allowing for the fractal dimension to be used as a tool to study different populations of galaxies. All results confirm the decades old theoretical prediction of a decrease in the fractal dimension for z>1.
Journal Article
Distinct modes of interaction within eIF4F-like complexes and susceptibility to the RocA inhibitor for the Trypanosoma brucei EIF4AI translation initiation factor
by
da Silva, Adalúcia
,
Moura, Danielle M. N.
,
Assis, Ludmila A.
in
Analysis
,
Binding
,
Chemical properties
2025
Trypanosomatids are parasitic protozoa responsible for major human diseases which are characterized by unique gene expression mechanisms. mRNA translation in these parasites is associated with multiple eIF4F-like complexes, required for mRNA recruitment and ribosome binding. The eukaryotic eIF4F is generally known to require the action of eIF4A, an ATP-dependent RNA helicase, in order to function properly, but not all trypanosomatid eIF4F complexes might require EIF4AI, their single eIF4A homologue. In mammals, eIF4A is known to be targeted by specific inhibitors and can thus be considered a potential target for a selective inhibition of translation in these parasites. Here, aiming to better define the EIF4AI functionality, we started by investigating its interactome in Trypanosoma brucei , confirming a strong interaction with only one of five eIF4F-like complexes found in trypanosomatids, based on the EIF4E4/EIF4G3 subunits. Nevertheless, when the interactome of a mutant EIF4AI (DEAD/DQAD), known to be impacted on its ATPase activity, was investigated, the only eIF4F-like complex found was based on the EIF4E3/EIF4G4 pair, with many translation-related and other proteins also found with the mutant protein. When both wild-type and mutant proteins were also investigated through a fluorescent-based tethering assay, a stimulatory effect on mRNA expression was confirmed for EIF4AI, but not for the mutant protein. Sensitivity to the Rocaglamide A (RocA) inhibitor, which targets the mammalian eIF4A, was also investigated, with the inhibitor blocking the stimulation seen on the tethering assay. Parasite susceptibility to RocA was further assessed in T. brucei and Leishmania infantum , with both, and specially T. brucei , being much less susceptible to the drug than mammalian cells. This phenotype correlates with changes in EIF4AI within the RocA binding pocket where, in comparison with the mammalian eIF4A, a phenylalanine to valine substitution in the T. brucei EIF4AI likely impairs RocA binding. Our results help better define the EIF4AI mode of action in T. brucei and provide relevant data which might support future searches for specific EIF4AI inhibitors.
Journal Article
Structure of the moiré exciton captured by imaging its electron and hole
by
Pareek, Vivek
,
Zhu, Xing
,
Heinz, Tony F.
in
639/624/399
,
639/766/119/1000/1018
,
639/925/357/1018
2022
Interlayer excitons (ILXs) — electron–hole pairs bound across two atomically thin layered semiconductors — have emerged as attractive platforms to study exciton condensation
1
–
4
, single-photon emission and other quantum information applications
5
–
7
. Yet, despite extensive optical spectroscopic investigations
8
–
12
, critical information about their size, valley configuration and the influence of the moiré potential remains unknown. Here, in a WSe
2
/MoS
2
heterostructure, we captured images of the time-resolved and momentum-resolved distribution of both of the particles that bind to form the ILX: the electron and the hole. We thereby obtain a direct measurement of both the ILX diameter of around 5.2 nm, comparable with the moiré-unit-cell length of 6.1 nm, and the localization of its centre of mass. Surprisingly, this large ILX is found pinned to a region of only 1.8 nm diameter within the moiré cell, smaller than the size of the exciton itself. This high degree of localization of the ILX is backed by Bethe–Salpeter equation calculations and demonstrates that the ILX can be localized within small moiré unit cells. Unlike large moiré cells, these are uniform over large regions, allowing the formation of extended arrays of localized excitations for quantum technology.
Imaging the electron and hole that bind to form interlayer excitons in a 2D moiré material enables direct measurement of its diameter and indicates the localization of its centre of mass.
Journal Article
Comparison among Different Green Extraction Methods of Polyphenolic Compounds from Exhausted Olive Oil Pomace and the Bioactivity of the Extracts
by
Morais, Rui M. S. C.
,
Martins, Valter F. R.
,
Morais, Alcina M. M. B.
in
Antimicrobial agents
,
Antioxidants
,
Antioxidants - chemistry
2024
The use of by-products as a source of bioactive compounds with economic added value is one of the objectives of a circular economy. The olive oil industry is a source of olive pomace as a by-product. The olive pomace used in the present study was the exhausted olive pomace, which is the by-product generated from the air drying and subsequent hexane extraction of residual oil from the olive pomace. The objective was to extract bioactive compounds remaining in this by-product. Various types of green extraction were used in the present study: solvent extraction (water and hydroalcoholic); ultrasound-assisted extraction; Ultra-Turrax-assisted extraction; and enzyme-assisted extraction (cellulase; viscoenzyme). The phenolic profile of each extract was determined using HPLC-DAD and the total phenolic content (TPC) and antioxidant activity (ABTS, DPPH, and ORAC) were determined as well. The results showed significant differences in the yield of extraction among the different methods used, with the enzyme-assisted, with or without ultrasound, extraction presenting the highest values. The ultrasound-assisted hydroethanolic extraction (USAHE) was the method that resulted in the highest content of the identified phenolic compounds: 2.021 ± 0.29 mg hydroxytyrosol/100 mg extract, 0.987 ± 0.09 mg tyrosol/100 mg extract, and 0.121 ± 0.005 mg catechol/100 mg extract. The conventional extraction with water at 50 °C produced the best results for TPC and antioxidant activity of the extracts. The extracts from the USAHE were able to inhibit Gram-positive bacteria, especially Bacillus cereus, showing 67.2% inhibition at 3% extract concentration.
Journal Article
MicroRNA signature refine response prediction in CML
2019
microRNAs (miRs) dysregulation have emerged as a crucial step in tumorigenesis, being related with cancer development, progression and response to treatment. In chronic myeloid leukaemia (CML), the resistance to tyrosine kinase inhibitors (TKI) is responsible for treatment failure and could be linked to changes in miRs expression. This work aimed to correlate the expression levels of 3 miRs, miR-21, miR-26b and miR-451, with response to TKI treatment in CML patients. miR-451 levels at diagnosis were significantly higher in patients with optimal response after 6 and 12 months of therapy. Conversely, patients without optimal response had highest levels of miR-21. miR-21 and miR-451 appear to be good biomarkers of response, able to predict optimal TKI responders (p < 0.05). Using the combined profile of both miRs, we create a predictive model of optimal response after one year of treatment. This study highlights the role of miR-21 and miR-451 expression levels at diagnosis in predicting which patients achieve the optimal response.
Journal Article