In recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic ...antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatings.
The size of silicon transistors used in microelectronic devices is shrinking to the level at which quantum effects become important. Although this presents a significant challenge for the further ...scaling of microprocessors, it provides the potential for radical innovations in the form of spin-based quantum computers and spintronic devices. An electron spin in silicon can represent a well-isolated quantum bit with long coherence times because of the weak spin-orbit coupling and the possibility of eliminating nuclear spins from the bulk crystal. However, the control of single electrons in silicon has proved challenging, and so far the observation and manipulation of a single spin has been impossible. Here we report the demonstration of single-shot, time-resolved readout of an electron spin in silicon. This has been performed in a device consisting of implanted phosphorus donors coupled to a metal-oxide-semiconductor single-electron transistor-compatible with current microelectronic technology. We observed a spin lifetime of ∼6 seconds at a magnetic field of 1.5 tesla, and achieved a spin readout fidelity better than 90 per cent. High-fidelity single-shot spin readout in silicon opens the way to the development of a new generation of quantum computing and spintronic devices, built using the most important material in the semiconductor industry.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper describes the operation of the Coherent CAPTAIN-Mills (CCM) detector located at the Los Alamos Neutron Science Center at Los Alamos National Laboratory. CCM is a 10-ton liquid argon ...detector located 20 meters from a high flux neutron/neutrino source and is designed to search for sterile neutrinos (νs’s) and light dark matter (LDM). An engineering run was performed in fall 2019 to study the characteristics of the CCM120 detector by searching for coherent scattering signals consistent with νs’s and LDM resulting from the production and decays of π+ and π0 in the tungsten target. New parameter space in a leptophobic dark matter (DM) model was excluded for DM masses between ~2.0 and 30 MeV. The lessons learned from this run have guided the development and construction of the new CCM200 detector that will begin operations in 2021 and significantly improve on these searches.
A vast number of bacterial extracellular polysaccharides (EPSs) have been reported over recent decades, and their composition, structure, biosynthesis and functional properties have been extensively ...studied. Despite the great diversity of molecular structures already described for bacterial EPSs, only a few have been industrially developed. The main constraints to full commercialization are their production costs, mostly related to substrate cost and downstream processing. In this article, we review EPS biosynthetic and fermentative processes, along with current downstream strategies. Limitations and constraints of bacterial EPS development are stressed and correlation of bacterial EPS properties with polymer applications is emphasized.
Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially ...eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Phase angle and mortality: a systematic review Garlini, Luíza M; Alves, Fernanda D; Ceretta, Luciane B ...
European journal of clinical nutrition,
04/2019, Letnik:
73, Številka:
4
Journal Article
Recenzirano
The phase angle, expressed through bioelectrical impedance, has been studied as a prognostic marker in several health conditions. As this issue is still conflicting, the question whether this ...parameter correlates with mortality in the most diverse clinical situations remains. Therefore, this study aimed to evaluate the relationship between phase angle and mortality through a systematic review of the literature.
This research was conducted in electronic databases (Pubmed, Embase, Cochrane, Lilacs, Scielo, e Scopus), and included studies that had phase angle as a variable of interest and mortality/survival as an outcome. Data were extracted independently by two reviewers and disagreements were assessed by a third reviewer.
Forty-eight of 455 papers were assessed and an amount of 42 showed a correlation between phase angle and mortality.
Phase angle seems to be a good indicator for mortality in many clinical situations and can be used in screening individuals prone to this outcome.
•FucoPol/chitosan bilayer films were prepared for application in food packaging.•Bilayer films showed good optical and mechanical properties.•Bilayer films are poor barriers to water vapour but ...excellent barriers to gases.•Bilayers presented enhanced properties comparing to FucoPol monolayer films.
Bilayer films of FucoPol and chitosan were prepared and characterized in terms of optical, morphologic, hygroscopic, mechanical and barrier properties, to evaluate their potential application in food packaging. Bilayer films have shown dense and homogeneous layers, and presented enhanced properties when comparing to monolayer FucoPol films. Though, a high swelling degree in contact with liquid water (263.3%) and a high water vapour permeability (0.75×10−11mol/msPa), typical of polysaccharide films, was still observed. However, they presented a low permeability to O2 and CO2 (0.47×10−16molm/m2sPa and 5.8×10−16molm/m2sPa, respectively). Tensile tests revealed a flexible and resistant film with an elongation at break of 38% and an elastic modulus of 137MPa. The studied properties, in particular the excellent barrier to gases, impart these bilayer films potential to be used in packaging of low moisture content products, as well as in multilayered hydrophobic/hydrophilic/hydrophobic barriers for food products with a broader range of water content.
A pineapple peel hydroalcoholic extract rich in phenolic compounds, was stabilized by microencapsulation using spray drying technology, with maltodextrin, inulin, and arabic gum as wall materials. ...The influence of the type of wall material and drying temperature (150 and 190 °C) on the particles properties was studied. The particles presented a spherical shape with a diameter ranging from approximately 1.3 to 18.2 µm, the exception being the ones with inulin that showed a large degree of agglomeration. All powders produced presented an intermediate cohesiveness and a fair to good flowability according to Carr index and Hausner ratio, which envisages suitable handling properties at an industrial scale. The microencapsulation processes using maltodextrin and arabic gum at 150 °C were the ones that showed higher maintenance of the antioxidant activity of compounds present in the extract before encapsulation during spray drying. In addition, the microparticles obtained were quite efficient in stabilizing the encapsulated phenolic compounds, as their antioxidant activity did not change significantly during six months of storage at 5 °C.
G protein coupled receptors (GPCRs) are a class of membrane proteins that sense extracellular signals ranging from light to odorants and small molecules and activate intracellular signaling pathways ...that control important physiological responses. Being composed of 7 transmembrane helices linked by extracellular and intracellular loops, the great majority of the sequence of these receptors is embedded in the lipid membrane. Therefore, it is expected GPCR structure and function to be impacted by the surrounding lipid environment and the lipid membrane physico-chemical and mechanical properties. A large number of examples from the literature is provided to highlight the role of the lipid nature (lipid headgroup, membrane polyunsaturation and cholesterol) and membrane physical and mechanical properties (curvature elastic stress, membrane thickness and hydrophobic mismatch, fluidity) in the activity of different GPCRs. In addition, lipids are important co-factors being identified in very specific locations in several GPCR structures. GPCRs and G proteins can also be lipid post-translationally modified and such events can significantly impact membrane binding, trafficking and signaling. These aspects are all treated in this review. Understanding how the lipid can modulate GPCR activity is important not only from a fundamental point of view but also due to the fact that certain pathologies, where GPCRs are central targets, have been associated with important lipid imbalance. Establishing a link between the lipid pathological imbalance and the receptor functioning in such environment is thus essential as it can open avenues to potentially innovative therapeutic strategies.
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•G-protein coupled receptors (GPCRs) are inserted in lipid membranes.•Lipids regulate membrane physico-chemical and mechanical properties of membranes.•GPCRs are impacted by the lipid environment.•Lipids are GPCR co-factors.•GPCRs and effectors are lipidated.
Background
International studies indicate that job satisfaction and burnout interfere with the safety climate and quality of care. However, no evidence of such relationships is available for ...Brazilian paediatric hospitals.
Aims
To assess the correlation and predictive effect of emotional exhaustion and job satisfaction on the perception of professional nurses at paediatric hospitals regarding safety climate and quality of care.
Design
Cross‐sectional correlational design.
Methods
The study was conducted with registered nurses, technician and assistant nurses from two Brazilian paediatric hospitals over 3 months in 2013–2014 using instruments to assess safety climate, quality of care, job satisfaction and emotional exhaustion.
Results
Data related to 267 professional nurses from 15 inpatient wards and 3 intensive care units were analysed. Overall, the respondents exhibited moderate emotional exhaustion, were satisfied with their jobs and considered the quality of care as good. However, the respondents exhibited low concordance as to the positive perception of the safety climate. The variables, emotional exhaustion and job satisfaction, exhibited significant correlations with safety climate and were considered predictive of the latter.
Conclusion
Emotional exhaustion and job satisfaction among professional nurses influence the safety climate at paediatric hospitals.
Implications for nursing or health policy
Investments to reduce emotional exhaustion and to improve job satisfaction among professional nurses allocated to paediatric hospitals might contribute to the patients' safety.
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