8 research outputs found
Incorporation of curcumin-loaded lactoferrin nanohydrogels into a model gelatine: release kinetics and characterization
The design and development of whey protein nanostructures as encapsulating agents for nutraceuticals controlled release has been intensively studied towards the production of functional foods. However, the interactions of these structures with food matrices are not well understood at the nanoscale and therefore they must be addressed. In this study, a curcumin- loaded lactoferrin (LF) nanohydrogel was developed aiming at its behaviour evaluation when incorporated into a model food matrix (gelatine). The release kinetics of curcumin from LF nanohydrogels added to food simulants (hydrophilic medium: ethanol 10%; and lipophilic medium: ethanol 50%) were performed at 25 °C (according to the Commission regulation EU No 10/2011). The resulting experimental data were fitted by the linear superimposition model (LSM) aiming at the evaluation of the release mechanisms of curcumin through LF nanohydrogels. This system was then incorporated into an unflavoured commercial gelatine and further characterized. For this purpose, the protein nanohydrogel isolated and loaded with curcumin was dehydrated by freeze-drying, resulting in a homogeneous LF-curcumin powder. Freeze-dried nanohydrogels were characterized by dynamic light scattering (DLS), circular dichroism (CD) and fluorometry. LF nanohydrogel showed higher release of curcumin in a lipophilic food simulant (ca. 16 g) in comparison with a hydrophilic one (ca. 1.6 g). Curcumin release kinetics through LF nanohydrogels have shown to be mainly driven by Case II transport, rather than Fickian diffusion, in both simulants. The behaviour of this system and curcumin release kinetics in food stimulants showed that LF nanohydrogel has a huge potential for the controlled release of lipophilic nutraceuticals in refrigerated food products of hydrophilic character. Finally, LF nanohydrogels were successfully incorporated in a gelatine matrix and showed no degradation in this process.FCTNORTE 2020COMPETE 2020This work was supported by the Portuguese Foundation for Science and Technology (FCT) under
the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-
0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by
European Regional Development Fund under the scope of Norte2020, Programa Operacional
Regional do Norte. Óscar L. Ramos gratefully acknowledges FCT for his financial grant with
reference SFRH/BPD/80766/2011.
João F. Araújo acknowledges the Escola de Ciências and Centro de Engenharia Biológica from
Universidade do Minho (Braga, Portugal) for their support, under the scope of the Biophysics
and Bionanosystems Master program.info:eu-repo/semantics/publishedVersio
Palinologia holocênica do testemunho Bom Jesus, margem leste da ilha do Marajó, Pará, Amazônia
Physicochemical characterisation and release behaviour of curcumin-loaded lactoferrin nanohydrogels into food simulants
Whey protein nanostructures can be used as vehicles for the incorporation of nutraceuticals (e.g., antioxidants or vitamins) aimed at the development of functional foods, because nanostructures provide greater protection, stability and controlled release to such nutraceuticals. Fundamental knowledge is required regarding the behaviour of nanostructures when associated with nutraceuticals and their interactions with real food matrices. In this study, a lactoferrin (LF) nanohydrogel was developed to encapsulate curcumin (nutraceutical model) and its behaviour was evaluated in terms of the LF structure and the interaction with curcumin. The release kinetics of curcumin from LF nanohydrogels was also assessed using food simulants with a hydrophilic nature (10% ethanol) and lipophilic nature (50% ethanol). This system was able to encapsulate curcumin at 80 µg mL-1 with an efficiency of ca. 90% and loading capacity of ca. 3%. Through spectroscopic characterisation, it is suggested that LF and curcumin bind via hydrophobic interactions and the average binding distance between LF and curcumin was found to be 1.91 nm. Under refrigerated conditions (4 °C), this system showed stability for up to 35 days, while at room temperature (25 °C) it was shown to be stable for up to 14 days of storage. The LF nanohydrogel presented higher release rates of curcumin in a lipophilic food simulant (stable after ca. 7 h) as compared to a hydrophilic simulant (stable after ca. 4 h). LF nanohydrogels were successfully incorporated into a gelatine matrix and showed no degradation in this process. The behaviour of this system and the curcumin release kinetics in food stimulants make the LF nanohydrogel an interesting system to associate with lipophilic nutraceuticals and to incorporate in refrigerated food products of a hydrophilic nature.Oscar Leandro Ramos gratefully acknowledge the Fundação para a Ciência e Tecnologia (FCT, Portugal) for their fellowships (SFRH/BPD/80766/2011). The authors would like to acknowledge to Rui Rodrigues from the Centre of Biological Engineering of University of Minho, for assistance in several analytical techniques. This study was supported by FCT under the scope of the strategic funding of UID/Multi/50016/2019
and UID/BIO/04469/2013 units and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte 2020 – Programa Operacional Regional do Norte. This study was also supported
by FCT under the scope of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462).info:eu-repo/semantics/publishedVersio
In vitro culture supplementation of EGF for improving the survival of equine preantral follicles
Hunting strategies used in the semi-arid region of northeastern Brazil
<p>Abstract</p> <p>Hunting for wild animals is stimulated by the many different human uses of faunal resources, and these animals constitute important subsistence items in local communities in the Caatinga region. In order to gain access to these resources, hunters have developed a series of techniques and strategies that are described in the present work. The principal hunting techniques encountered were: waiting, especially directed towards hunting diurnal birds; calling ("arremedo"), a technique in which the hunters imitate the animal's call to attract it to close range; hunting with dogs, a technique mostly used for capturing mammals; tracking, a technique used by only a few hunters who can recognize and follow animal tracks; and "facheado", in which the hunters go out at night with lanterns to catch birds in their nests. Additionally, many animal species are captured using mechanical traps. The types of traps used by the interviewees were: dead-fall traps ("quixó"), iron-jaw snap traps ("arataca"), wooden cages with bait ("arapuca"), iron-cage traps ("gaiola'), "visgo", multi-compartment bird cages ("alçapão"), buried ground traps with pivoted tops ("fojo"), and nooses and cages for carnivorous. The choice of which technique to use depends on the habits of the species being hunted, indicating that the hunters possess a wide knowledge of the biology of these animals. From a conservation perspective, active hunting techniques (waiting, imitation, hunting with dogs, and "facheado") have the greatest impact on the local fauna. The use of firearm and dogs brought greater efficiency to hunting activities. Additional studies concerning these hunting activities will be useful to contribute to proposals for management plans regulating hunting in the region – with the objective of attaining sustainable use of faunal resources of great importance to the local human communities.</p
Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies
Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies.
Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality.
Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001).
Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status
NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics
Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data