233 research outputs found
Spectral Optical Properties of Rabbit Brain Cortex between 200 and 1000 nm
The knowledge of the optical properties of biological tissues in a wide spectral range
is highly important for the development of noninvasive diagnostic or treatment procedures. The
absorption coefficient is one of those properties, from which various information about tissue
components can be retrieved. Using transmittance and reflectance spectral measurements acquired
from ex vivo rabbit brain cortex samples allowed to calculate its optical properties in the ultraviolet
to the near infrared spectral range. Melanin and lipofuscin, the two pigments that are related to the
aging of tissues and cells were identified in the cortex absorption. By subtracting the absorption of
these pigments from the absorption of the brain cortex, it was possible to evaluate the true ratios for
the DNA/RNA and hemoglobin bands in the cortex—12.33-fold (at 260 nm), 12.02-fold (at 411 nm)
and 4.47-fold (at 555 nm). Since melanin and lipofuscin accumulation increases with the aging of the
brain tissues and are related to the degeneration of neurons and their death, further studies should
be performed to evaluate the evolution of pigment accumulation in the brain, so that new optical
methods can be developed to aid in the diagnosis and monitoring of brain diseases.The work of L.M.O. was supported by the Portuguese Science Foundation, Grant No.
FCT-UIDB/04730/2020. The work of V.V.T. was supported by the Government of the Russian
Federation (project No. 075-15-2019-1885 to support scientific research projects implemented under
the supervision of leading scientists at Russian institutions, Russian institutions of higher education).info:eu-repo/semantics/publishedVersio
Fast decellularization process using supercritical carbon dioxide for trabecular bone
Decellularization is a process that consists on the removal of immunogenic cellular material from a tissue, so that
it can be safely implanted as a functional and bioactive scaffold. Most decellularization protocols rely on the use
of harsh chemicals and very long washing processes, leading to severe changes in the ultrastructure and loss of
mechanical integrity. To tackle these challenges, supercritical carbon dioxide (scCO2) is herein proposed as an
alternative methodology for assisting decellularization of porcine trabecular bone tissue and is combined, for the
first time, with Tri(n-butyl) phosphate (TnBP). Histological and DNA analysis revealed that both TnBP and scCO2
were able to extract the DNA content from the scaffolds, being this effect more pronounced in treatments that
used TnBP as a co-solvent. The combined protocol led to a decrease in DNA content by at least 90%, demon-
strating the potential of this methodology and opening new possibilities for future optimizations.info:eu-repo/semantics/publishedVersio
Keep on running – a randomized controlled trial to test a digital evidence-based intervention for sustained adoption of recreational running: rationale, design and pilot feasibility study
Background: This paper describes the rationale, intervention
development, study design and results from the pilot feasibility
study of the Keep On Running (KOR) trial. KOR aims to test a
web-based brief theory-based intervention, targeting
maintenance of recreational running behavior over time (i.e.
relapse preventing).
Methods: Intervention development was based both on Self-
Determination Theory and on Self-Regulation Theory. As part of
it, a pilot study was implemented (n=18) to measure intervention
adherence and participant satisfaction in order to establish the
feasibility and acceptability of the intervention toolkit.
Furthermore, this pilot study was also used to test the feasibility
and acceptability of the questionnaires selected to be part of the
later RCT.
Results: Pilot intervention acceptability was good, but overall
adherence was low. Features such as feedback and social sharing
should be added to the toolkit. The main trial should lessen
questionnaire length and include data from usual monitoring
gadgets and apps (APIs). The protocol of the RCT was adjusted to
test the efficacy of the refined final version of the intervention,
and the RCT that will test it, contributing to the understanding of
recreational running sustainability, allowing the optimization of
future interventions aimed at physical activity promotion.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/acceptedVersio
Fast calculation of spectral optical properties and pigment content detection in human normal and pathological kidney
A fast calculation method was used to obtain the spectral optical properties of human normal and pathological (chromophobe renal cell carcinoma) kidney tissues. Using total transmittance, total reflectance and collimated transmittance spectra acquired from ex vivo kidney samples, the spectral optical properties of both tissues, namely the absorption, the scattering and the reduced scattering coefficients, as well as the scattering anisotropy, dispersion and light penetration depth, were calculated between 200 and 1000 nm. Analysis of the mean ab sorption coefficient spectra of the kidney tissues showed that both contain melanin and lipofuscin, and that 83 % of the melanin in the normal kidney converts into lipofuscin in the pathological kidney.info:eu-repo/semantics/publishedVersio
The Emerging Role of microRNAs in Aquaporin Regulation
Aquaporins (AQPs) are membrane channels widely distributed in human tissues. AQPs are essential for water and energy homeostasis being involved in a broad range of pathophysiological processes such as edema, brain injury, glaucoma, nephrogenic diabetes insipidus, salivary and lacrimal gland dysfunction, cancer, obesity and related metabolic complications. Compelling evidence indicates that AQPs are targets for therapeutic intervention with potential broad application. Nevertheless, efficient AQP modulators have been difficult to find due to either lack of selectivity and stability, or associated toxicity that hamper in vivo studies. MicroRNAs (miRNAs) are naturally occurring small non-coding RNAs that regulate post-transcriptional gene expression and are involved in several diseases. Recent identification of miRNAs as endogenous modulators of AQP expression provides an alternative approach to target these proteins and opens new perspectives for therapeutic applications. This mini-review compiles the current knowledge of miRNA interaction with AQPs highlighting miRNA potential for regulation of AQP-based disorders
Longitudinal distribution and lateral pattern of megalopal settlement and juvenile recruitment of Carcinus maenas (L.) (Brachyura, Portunidae) in the Mira River Estuary, Portugal
Settlement is a critical process in the life history of crabs, and thus affecting the abundance, distribution and structure of estuarine communities.
The spatial pattern of settlement of megalopae of the shore crab Carcinus maenas along a longitudinal estuarine gradient (Mira River
Estuary, Portugal) was examined, as well as its effects on the juvenile population. To measure megalopal settlement, four replicate collectors
were deployed in six equally spaced stations along the estuarine axis. Juveniles were collected on the same locations with a quadrat randomly
deployed on the substrate. To assess fine-scale megalopal settlement within a curved region of the estuary, replicate collectors were deployed on
both margins along Moinho da Asneira curve. Megalopae settled differently along the six longitudinal points, with a tendency to attenuate their
settlement upstream. Within the curved region, megalopae preferentially settled on the left margin collectors, probably due to the weaker velocity
speeds felt on this margin. Concerning the overall juvenile density, there were significant differences among the stations distributed along
the estuary, but they did no reflect a longitudinal dispersion attenuation pattern. Size-frequency distribution of the juvenile population showed
that the average size is higher on the left margin. Recruits (carapace length between 1.0 mm and 3.4 mm) were more abundant on the upstream
stations. Density of early juveniles (3.4 mme6.5 mm) and juveniles (6.5 mme10 mm) was more stable throughout the estuary axis than that of
recruits. This distribution pattern may result from tidal excursion processes or mechanisms to avoid biotic interactions, such as predation and
competition
Influence of mixtures of acenaphthylene and benzo[a] anthracene on their degradation by Pleurotus ostreatus in sandy soil
Purpose Polycyclic aromatic hydrocarbons (PAHs) are a class
of organic compounds commonly found as soil contaminants.
Fungal degradation is considered as an environmentally
friendly and cost-effective approach to remove PAHs from
soil. Acenaphthylene (Ace) and Benzo[a]anthracene (BaA)
are two PAHs that can coexist in soils; however, the influence
of the presence of each other on their biodegradation has not
been studied. The biodegradation of Ace and BaA, alone and
in mixtures, by the white rot fungus Pleurotus ostreatus was
studied in a sandy soil.
Materials and methods Experimental microcosms containing
soil spiked with different concentrations of Ace and BaAwere
inoculated with P. ostreatus. Initial (t 0) and final (after 15 days
of incubation) soil concentrations of Ace and BaA were determined
after extraction of the PAHs.
Results and discussion P. ostreatus was able to degrade
57.7% of the Ace in soil spiked at 30 mg kg−1 dry soil and
65.8% of Ace in soil spiked at 60 mg kg−1 dry soil. The
degradation efficiency of BaA by P. ostreatus was 86.7 and
77.4% in soil spiked with Ace at 30 and 60 mg kg−1 dry soil,
respectively. After 15 days of incubation, there were no significant
differences in Ace concentration between soil spiked
with Ace and soil spiked with Ace + BaA, irrespective of the
initial soil concentration of both PAHs. There were also no
differences in BaA concentration between soil spiked with
BaA and soil spiked with BaA + Ace.
Conclusions The results indicate that the fungal degradation
of Ace and BaA was not influenced by the presence of each
other’s PAH in sandy soil. Bioremediation of soils contaminated
with Ace and BaA using P. ostreatus is a promising
approach to eliminate these PAHs from the environment
Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets
Research Areas: Science & Technology ; Other TopicsABSTRACT - The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat
deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets
with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5)
and received, during a four week-period, a basal diet without supplementation (control) or
supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two
amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found
improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant
over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability.
Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.info:eu-repo/semantics/publishedVersio
From the Plate Tectonics to the Evolution Theory; from the supercontinents to the dispersion of the living beings
RESUMO: A evolução do conhecimento do interior do nosso planeta tem
levado a profundas alterações da forma como a dinâmica da Terra é encarada,
evidenciando a existência de ciclo dos supercontinentes. Esta transformação
tem permitido uma visão mais integradora, onde os processos tectónicos e
de evolução da Vida na Terra surgem como complementares. No entanto,
esta nova abordagem ainda não se reflete nos curricula do ensino. A realiza ção de um conjunto de atividades práticas explorando a forma como os
grandes blocos continentais foram evoluindo, desde o supercontinente
Rodínia até à Atualidade, e a sua influência na dispersão de alguns dos prin cipais grupos de seres vivos, constitui uma abordagem eficiente de alguns
aspetos associados ao ciclo dos supercontinentes.ABSTRACT: The evolution of the understanding of the behaviour of the inner
layers of our planet led to deep changes in the way we see the Earth
dynamics, emphasizing the existence of a supercontinent cycle. This allows
an integrative perspective, where the Plate Tectonics and the Evolution of
Life on Earth are no longer isolated processes, but the result of a common
evolution. However, such innovative view is not yet reflected in the scholar
curricula. In this work, we propose a set of practical activities for the sec ondary school level exploiting the concept ofsupercontinent cycle and disper sion of Life on Earth. The reconstruction of the dispersion of the major
continental blocks,since Rodínia to the Actuality, allows the understanding,
not only of the aggregation and dispersion of supercontinents (Rodínia →
Panotia → Pangaea), but also the way they have influenced the dispersion
of some of the major groups of animals in the Earth.info:eu-repo/semantics/publishedVersio
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