339 research outputs found
Resposta da couve Tronchuda (Brassica oleracea var. costata) à aplicação de azoto e boro e de um fertilizante orgânico autorizado em agricultura biológica
Os portugueses são dos maiores apreciadores mundiais de brássicas. A couve Tronchuda é cultivada em Portugal em área superior a 1000 ha. O seu consumo é sobretudo apreciado na quadra natalÃcia. Neste trabalho reportam-se resultados da fertilização com azoto e boro, na forma de adubos convencionais, e da utilização de Dix10 (com 10 % N total), um fertilizante orgânico autorizado em agricultura biológica. Plantas de raiz protegida foram transplantadas a 29 de Agosto de 2005 num compasso 0,8x0,5 m. O solo, de textura franca, continha 0,83 % matéria orgânica, 5,2 pH(H2O) e teores em P e K médios e altos, respectivamente. Foram estabelecidas seis modalidades: sem adubação (SAd); Dix10, em dose equivalente a 80 kg N/ha; modalidades com 80 (NB) e 160 (N+) kg N/ha, na forma de ureia; e modalidades sem B (B-) e com aplicação de 2,2 (NB) e 4,4 (B+) kg B/ha. Todas as modalidades de B foram fertilizadas com 80 kg N/ha e as de N com 2,2 kg B/ha, coincidindo na modalidade NB as doses médias de N e B. As plantas SAd produziram 13,7 Mg biomassa/ha e exportaram 33,9 kg N/ha e 40,9 g B/ha, valores significativamente inferiores à s modalidades fertilizadas. Dix10 produziu 18,0 Mg de biomassa/ha e exportou 45,1 kg N/ha e 51,3 g B/ha. A modalidade NB originou maior produção de biomassa (38,6 Mg/ha) e N exportado (107,9 kg/ha) que as modalidades SAd e Dix10. A modalidade N+ não registou aumento de produção nem de N exportado comparativamente com NB. B+ não influenciou a produção de biomassa mas aumentou a concentração de B nos tecidos e o B exportado. N+ reduziu significativamente a concentração de B nos tecidos e o B exportado, sugerindo um efeito de antagonismo da aplicação de N sobre a absorção de B. As produções obtidas e a recuperação aparente de nutrientes mostraram que a redução de produção de biomassa nas modalidades SAd e Dix10 se deveu à reduzida disponibilidade de N no solo durante a estação de crescimento. The Portuguese are one of the greatest brassica consumers in the entire world. Tall cabbage is grown in Portugal over an area greater than 1000 ha. Tall cabbage consumption is very popular at Christmas time. In this work, results from nitrogen and boron application, as conventional fertilisers, and from the use of Dix10, an organic amendment (Ëœ 10 % total N) permitted in organic farming, are reported. Young cabbage plants were prepared in a greenhouse in micro-pots and transplanted with protected roots on August 29, 2005, spaced at 0.8x0.5 m between and within rows. The soil was loamy textured with 0.83 % organic matter, pH(H2O) 5.2, and with median P and high K content levels. Six treatments were established: SAd treatment, without any fertilization; Dix10, applied in a rate equivalent to 80 kg N/ha; NB and N+, with 80 and 160 kg N/ha as urea, respectively; and B-and B+ treatments, without B and with 4.4 kg B/ha as borax. Boron treatments were fertilised with 80 kg N/ha and N treatments with 2.2 kg B/ha. Thus, NB is a median treatment with 80 kg N/ha and 2.2 kg B/ha. SAd plants yielded 13.7 Mg biomass/ha and took up 33.9 kg N/ha and 40.9 g B/ha, which are values significantly lower than that obtained on fertilised plots. In Dix10 treatment, cabbage yielded 18 Mg biomass/ha and took up 45.1 and 51.3 g B/ha. NB treatment produced higher biomass (38.6 Mg/ha) and N uptake (107.9 kg/ha) than SAd and Dix10 treatments. N+ treatment did not increase the yield, neither N uptake if compared with NB. B+ treatment has not any influence in biomass yield but increased tissue B content and B uptake. In N+ treatment there was a significant decrease in tissue B concentration and B uptake, which suggests antagonism of N over the uptake of B. The biomass yields and the apparent N and B recoveries showed that the lower biomass yielded in SAd and Dix10 treatments were due to a shortage of soil N availability in these treatments during the growing season
Resposta da couve Tronchuda (Brassica oleracea var costata) à aplicação de azoto, boro e um fertilizante orgânico para agricultura biológica
Contaminação de águas associadas a mineralizações de W de Fonte Santa, NE Portugal
Na região da mina de Fonte Santa ocorrem filões de quartzo mineralizados em W, com scheelite, que cortam os quartzitos do OrdovÃcico Inferior e estão relacionados com a zona de cisalhamento de Moncorvo-Bemposta. Alguns filões com scheelite têm quartzo recristalizado e brechificado e sulfuretos, tendo sido explorados para W entre 1942 e 1982. As águas relacionadas com a mina da Fonte Santa são pouco mineralizadas, com condutividade eléctrica < 965 μ S/cm, e classificadas como de tipo misto. A maioria dos valores de pH (pH = 5.0 - 8.5) indicam que não há drenagem ácida significativa associada à s actividades mineiras e os valores mais ácidos (pH = 3.4) foram obtidos numa lagoa da mina. Nas águas associadas com os filões mineralizados e antigas explorações foram encontradas concentrações elevadas de Fe e Mn que proÃbem o seu consumo humano e utilização na agricultura
Rumex induratus leaves: phytochemical profiling and antioxidant activity
Several species of the Rumex (Polygonaceae) genus have been used in traditional medicine, although their high oxalic acid content has been implicated in oxalic intoxication, mainly la children. Rumex induratus Boiss & Reuter is an endemic Liberian herb that prefers rocky habitats of the thermo Mediterranean region
Agri-food surplus, waste and loss as sustainable biobased ingredients: a review
Ensuring a sustainable supply of food for the world’s fast growing population is a major challenge in today’s economy, as modern lifestyle and increasing consumer concern with maintaining a balanced and nutritious diet is an important challenge for the agricultural sector worldwide. This market niche for healthier products, especially fruits and vegetables, has increased their production, consequently resulting in increased amounts of agri-food surplus, waste, and loss (SWL) generated during crop production, transportation, storage, and processing. Although many of these materials are not utilized, negatively affecting the environmental, economic, and social segments, they are a rich source of valuable compounds that could be used for different purposes, thus preventing the losses of natural resources and boosting a circular economy. This review aimed to give insights on the efficient management of agri-food SWL, considering conventional and emerging recovery and reuse techniques. Particularly, we explored and summarized the chemical composition of three worldwide cultivated and consumed vegetables (carrots, broccoli and lettuce) and evaluate the potential of their residues as a sustainable alternative for extracting value-added ingredients for the development of new biodynamic productsThe authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support through the national funds FCT/MCTES to CIMO (UIDB/00690/2020) and
national funding by FCT, P.I., through the institutional scientific employment program contract for L.
Barros and A. Fernandes.info:eu-repo/semantics/publishedVersio
Phenolic compounds and bioactive properties of Ruscus aculeatus L. (asparagaceae): the pharmacological potential of an underexploited subshrub
Ruscus aculeatus L. is a subshrub used in traditional medicine in different parts of the world, namely in Europe and the Iberian Peninsula. According to reported folk knowledge, the aerial parts are mainly used as diuretics and the underground organs are used for the treatment of disorders of the urinary system and as a laxative. In this work, the aerial part and the roots and rhizomes of R. aculeatus were chemically characterized with regard to the content of phenolic compounds and bioactive properties. Aqueous (infusions and decoctions) preparations and hydroethanolic extracts from the two mentioned parts of the plant were prepared. Nine phenolic compounds were detected in all the extracts. Apigenin-C-hexoside-C-pentoside isomer II was the major compound in aqueous extracts and, in the hydroethanolic extract was quercetin-O-deoxyhexoside-hexoside followed by apigenin-C-hexoside-C-pentoside isomer II. All extracts revealed antioxidant activity and potential to inhibit some of the assayed bacteria; aqueous extracts of the aerial part and infusions of roots and rhizomes did not show cytotoxic effects on a non-tumor primary cell culture. This preliminary study provides suggestions of the biological potential associated with the empirical uses and knowledge of this species, in particular its bioactivities.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support through the national funds FCT/MCTES to CIMO (UIDB/00690/2020) and
national funding by FCT, P.I., through the institutional scientific employment program contract for
L. Barros, A. Fernandes, M.I. Dias, C. Pereira, and R.C. Calhelha. The authors are also grateful to
FEDER-Interreg España-Portugal program for financial support through the project TRANSCoLAB
0612_TRANS_CO_LAB_2_P and to European Regional Development Fund (ERDF) through the
Regional Operational Program North 2020, within the scope of Project Norte-01-0145-FEDER-
000042: GreenHealth.info:eu-repo/semantics/publishedVersio
Bioactive properties of Ruscus aculeatus L.: na underexploited subshrub
Ruscus aculeatus L. is a sub-shrub used in traditional medicine in different parts of the world,
namely in Europe and the Iberian Peninsula[1]. Traditionally, the aerial parts are mainly used as
diuretics and the underground parts are used for the treatment of urinary tract diseases and as a
laxative[2]. In the present work, the aerial part, roots, and rhizomes of R. aculeatus were
characterized regarding their bioactive properties in order to contribute to the knowledge of the
chemical composition of this unexplored species. The plant material of R. aculeatus was
harvested in April 2019 inside woodlands and hedgerows, in Valpaços, Portugal. Two distinct
parts were gathered: the aerial part (cladodes or laminar stems and lateral branches) and the
underground organs (rhizomes with roots). Hydroethanolic extracts and aqueous (infusions and
decoctions) preparations from the two mentioned parts of the plant were prepared.
Multi-resistant clinical bacterial strains (Enterococcus faecalis, Listeria monocytogenes,
methicillin-resistant Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae,
Morganela morganii, Proteus mirabilis and Pseudomonas aeruginosa) were used to screen the
antimicrobial activity and the antioxidant activity was evaluated through two different in vitro
assays: inhibition of lipid peroxidation in brain homogenates by thiobarbituric acid reactive
substances (TBARS) and oxidative hemolysis inhibition assay (OxHLIA). The cytotoxic
activity was assayed using MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung
carcinoma), HeLa (cervical carcinoma) and HepG2 (hepatocellular carcinoma) human tumor
cell lines, and also a non-tumor cell line (porcine liver primary cells, PLP2). All extracts
revealed antioxidant activity and potential to inhibit some of the assessed bacteria; except for
the infusion of the aerial part (for the lines MCF7 and HepG2) and decoction extracts (line
MCF7), all the remaining extracts presented effective results in the inhibition of the tested cell
lines; the aqueous extracts of the aerial part and infusions of roots and rhizomes did not show
cytotoxic effects in a non-tumor primary cell culture. This preliminary study provided
innovative and interesting results in relation to the bioactive properties of this little-studied and
explored wild plant.The authors are grateful to the Foundation for Science and Technology
(FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO
(UIDB/00690/2020) and national funding by FCT, P.I., through the institutional scientific
employment program-contract for L. Barros, A. Fernandes, C. Pereira and R.C. Calhelha´s
contract. The authors are grateful to the European Regional Development Fund (ERDF)
through the Regional Operational Program North 2020, within the scope of Project
Norte-01-0145-FEDER-000042: GreenHealth.info:eu-repo/semantics/publishedVersio
Targeting Infectious Agents as a Therapeutic Strategy in Alzheimer’s Disease
Alzheimer’s disease (AD) is the most prevalent dementia in the world. Its cause(s) are presently largely unknown. The most common explanation for AD, now, is the amyloid cascade hypothesis, which states that the cause of AD is senile plaque forma- tion by the amyloid β peptide, and the formation of neurofibrillary tangles by hyperphosphorylated tau. A second, burgeoning theory by which to explain AD is based on the infection hypothesis. Much experimental and epidemiological data support the involvement of infections in the development of dementia. According to this mechanism, the infection either directly or via microbial virulence factors precedes the formation of amyloid β plaques. The amyloid β peptide, possessing antimicrobial properties, may be beneficial at an early stage of AD, but becomes detrimental with the progression of the disease, concomi- tantly with alterations to the innate immune system at both the peripheral and central levels. Infection results in neuroinflam- mation, leading to, and sustained by, systemic inflammation, causing eventual neurodegeneration, and the senescence of the immune cells. The sources of AD-involved microbes are various body microbiome communities from the gut, mouth, nose, and skin. The infection hypothesis of AD opens a vista to new therapeutic approaches, either by treating the infection itself or modulating the immune system, its senescence, or the body’s metabolism, either separately, in parallel, or in a multi-step way.Basque Government under the grant “Artificial Intelligence in BCAM number EXP. 2019/00432
The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinos
We implement the seesaw mechanism in the 3-3-1 model with right-handed
neutrinos. This is accomplished by the introduction of a scalar sextet into the
model and the spontaneous violation of the lepton number. We identify the
Majoron as a singlet under symmetry, which makes it
safe under the current bounds imposed by electroweak data. The main result of
this work is that the seesaw mechanism works already at TeV scale with the
outcome that the right-handed neutrino masses lie in the electroweak scale, in
the range from MeV to tens of GeV. This window provides a great opportunity to
test their appearance at current detectors, though when we contrast our results
with some previous analysis concerning detection sensitivity at LHC, we
conclude that further work is needed in order to validate this search.Comment: about 13 pages, no figure
Equações de predição de valores energéticos de alimentos obtidas utilizando meta-análise e componentes principais
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