106 research outputs found
Semantic Reasoning in Context-Aware Assistive Environments to Support Ageing with Dementia
Lipase-catalyzed Reactions at Interfaces of Two-phase Systems and Microemulsions
This work describes the influence of two polar lipids, Sn-1/3 and Sn-2 monopalmitin, on the activity of lipase in biphasic systems and in microemulsions. In previous communications, we have shown that Sn-2 monoglycerides can replace Sn-1,3 regiospecific lipases at the oil–water interface, causing a drastically reduced rate of lipolysis. We here demonstrate that even if the lipase is expelled from the interface, it can catalyze esterification of the Sn-2 monoglyceride with fatty acids in both macroscopic oil–water systems and in microemulsions, leading to formation of di- and triglycerides
Environmental effects of crude oil spill on the physicochemical and hydrobiological characteristics of the Nun River, Niger Delta
Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid
BACKGROUND: Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption
Response of Benthic Foraminifera to organic matter quantity and quality and bioavailable concentrations of metals in Aveiro Lagoon (Portugal)
This work analyses the distribution of living benthic foraminiferal assemblages of surface sediments in different intertidal areas of Ria de Aveiro (Portugal), a polihaline and anthropized coastal lagoon. The relationships among foraminiferal assemblages in association with environmental parameters (temperature, salinity, Eh and pH), grain size, the quantity and quality of organic matter (enrichment in carbohydrates, proteins and lipids), pollution caused by metals, and mineralogical data are studied in an attempt to identify indicators of adaptability to environmental stress. In particular, concentrations of selected metals in the surficial sediment are investigated to assess environmental pollution levels that are further synthetically parameterised by the Pollution Load Index (PLI). The PLI variations allowed the identification of five main polluted areas. Concentrations of metals were also analysed in three extracted phases to evaluate their possible mobility, bioavailability and toxicity in the surficial sediment. Polluted sediment in the form of both organic matter and metals can be found in the most confined zones. Whereas enrichment in organic matter and related biopolymers causes an increase in foraminifera density, pollution by metals leads to a decline in foraminiferal abundance and diversity in those zones. The first situation may be justified by the existence of opportunistic species (with high reproduction rate) that can live in low oxic conditions. The second is explained by the sensitivity of some species to pressure caused by metals. The quality of the organic matter found in these places and the option of a different food source should also explain the tolerance of several species to pollution caused by metals, despite their low reproductive rate in the most polluted areas. In this study, species that are sensitive and tolerant to organic matter and metal enrichment are identified, as is the differential sensitivity/tolerance of some species to metals enrichment.CNPq [401803/2010-4]; [PEst-OE/CTE/UI4035/2014]info:eu-repo/semantics/publishedVersio
Metabarcoding of the kombucha microbial community grown in different microenvironments
Introducing of the DNA metabarcoding analysis of probiotic microbial communities allowed getting insight into their
functioning and establishing a better control on safety and efficacy of the probiotic communities. In this work the
kombucha poly-microbial probiotic community was analysed to study its flexibility under different growth conditions.
Environmental DNA sequencing revealed a complex and flexible composition of the kombucha microbial culture
(KMC) constituting more bacterial and fungal organisms in addition to those found by cultural method. The community
comprised bacterial and yeast components including cultured and uncultivable microorganisms. Culturing the
KMC under different conditions revealed the core part of the community which included acetobacteria of two genera
Komagataeibacter (former Gluconacetobacter) and Gluconobacter, and representatives of several yeast genera among
which Brettanomyces/Dekkera and Pichia (including former Issatchenkia) were dominant. Herbaspirillum spp. and Halomonas
spp., which previously had not been described in KMC, were found to be minor but permanent members of
the community. The community composition was dependent on the growth conditions. The bacterial component of
KMC was relatively stable, but may include additional member—lactobacilli. The yeast species composition was significantly
variable. High-throughput sequencing showed complexity and variability of KMC that may affect the quality
of the probiotic drink. It was hypothesized that the kombucha core community might recruit some environmental
bacteria, particularly lactobacilli, which potentially may contribute to the fermentative capacity of the probiotic drink.
As many KMC-associated microorganisms cannot be cultured out of the community, a robust control for community
composition should be provided by using DNA metabarcoding.National Academy of Sciences of Ukraine (N47/2013)http://www.amb-express.comhb201
Modulation of the regioselectivity of Thermomyces lanuginosus lipase via biocatalyst engineering for the Ethanolysis of oil in fully anhydrous medium
Time-resolved photoluminescence of delta-doped AlGaAs/GaAs heterostructures
The photoluminescence (PL) at low temperature of three delta-doped AlGaAs/GaAs heterostructures is investigated under continuous and pulsed excitations. The PL under continuous excitations allows the identification of the trapping centres and probes the carrier's transfer to the GaAs channel. The time-resolved photoluminescence (TRPL) inquires about carrier dynamics and gives radiative lifetimes of different levels. The DX level shows two time constants of the intensity decay relating the splitting of the valence band under impurity strains which reduce the crystal symmetry. The two time constants evolve with temperature and exhibit an increase near T = 50 K. (c) 2008 Elsevier B.V. All rights reserved
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