Perceived barriers for healthy eating by university employees at the workplace

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Diphenyl diselenide, a simple glutathione peroxidase mimetic, inhibits human LDL oxidation in vitro

Oxidative modification of low-density lipoprotein (LDL) represents an important factor in atherogenesis. In the present study, we have investigated the antioxidant capability of diphenyl diselenide (PhSe)2, a simple organoseleno compound, against copper (Cu2+) and peroxyl radical-induced human LDL oxidation in vitro. In initial studies using human serum, (PhSe)2 caused a dose-dependent inhibition of Cu2+-induced lipid peroxidation, which was correlated to thiol consumption. (PhSe)2 increased lipid peroxidation lag phase and decreased lipid peroxidation rate in isolated human LDL, evaluated by measuring both conjugated diene (CD) and thiobarbituric acid reactive substances (TBARS) levels. Consistent with these observations, (PhSe)2 showed a marked inhibitory effect on 2,2-azobis(2-amidinopropane dihydrochloride) (AAPH)-induced oxidation of LDL or parinaric acid (PnA) incorporated into LDL. (PhSe)2 also displayed a dose-dependent protective effect against Cu2+-induced lipid peroxidation in rat aortic slices. Interestingly, besides the antioxidant effects of (PhSe)2 toward the lipid moieties of LDL, which was related to its thiol-peroxidase activity, protein moieties from human isolated LDL were also protected against Cu2+-induced oxidation. The results presented herein are the first to show that (i) (PhSe)2 inhibits lipid peroxidation in human isolated LDL in vitro, (ii) this phenomenon is related to its thiol-peroxidase activity, and (iii) this chalcogen also prevents the oxidation of protein moieties of human LDL. Taken together, such data render (PhSe)2 a promising molecule for pharmacological studies with respect to the atherogenic process.http://www.sciencedirect.com/science/article/B6T12-4S21TS2-1/1/38250cf8bae4a4195ccd8905cf5c2a8

Unveiling biological activities of marine fungi: the effect of sea salt

There is an urgent need for new substances to overcome current challenges in the health sciences. Marine fungi are known producers of numerous compounds, but the manipulation of growth conditions for optimal compound production can be laborious and time-consuming. In Portugal, despite its very long coastline, there are only a few studies on marine fungi. From a collection of Portuguese marine fungi, we screened for antimicrobial, antioxidant, enzymatic, and cytotoxic activities. Mycelia aqueous extracts, obtained by high pressure-assisted extraction, and methanolic extracts of culture media showed high antioxidant, antimicrobial, and cytotoxic activities. The mycelium extracts of Cladosporium rubrum showed higher antioxidant potential compared to extracts from other fungi. Mycelia and culture media extracts of Aspergillus affinis and Penicillium lusitanum inhibited the growth of Staphylococcus aureus, Kocuria rhizophila, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, including multiresistant strains. Penicillium lusitanum and Trichoderma aestuarinum inhibited the growth of clinical strains of Candida albicans, C. glabrata, C. parapsilosis, and C. tropicalis. All extracts from culture media were cytotoxic to Vero cells. Sea salt induced alterations in the mycelium's chemical composition, leading to different activity profiles.info:eu-repo/semantics/publishedVersio

Long-term declines of wader populations at the Tagus estuary, Portugal: A response to global or local factors?

Migratory wader populations face global threats, mainly related to increasing rates of habitat loss and disturbance driven by human activities. To a large extent, the long-term survival of these populations requires the conservation of networks of sites along their migratory flyways. The Tagus estuary, Portugal, is among the most important wetlands for waders in the East Atlantic Flyway. Annual winter wader counts have been carried in this wetland since 1975 and a monthly roost-monitoring programme was implemented in 2007. Wintering populations of three out of the five most abundant species, Dunlin Calidris alpina, Grey Plover Pluvialis squatarola and Redshank Tringa totanus, showed significant population declines over the past three decades, which are most likely due to the loss and degradation of roost sites as a result of increasing human activity. The situation is unlikely to improve, as a high proportion of the wintering waders use roost sites that are situated in highly urbanised areas with no legal protection. The use of different roost sites by waders is highly variable both temporally and spatially, thus emphasizing the need for a network of good quality roost sites. Additionally, during migration, 60–80% of all the waders of the Tagus estuary concentrate at a single refuge, thus increasing the risk for wader populations during these periods. ------ RESUMO ------ As populações de aves limícolas migradoras enfrentam ameaças globais, maioritariamente relacionadas com a crescente perda de habitat e perturbação humana. Para garantir a sobrevivência a longo-termo destas populações é imprescindível a conservação de uma rede de áreas húmidas ao longo das suas rotas migratórias. O estuário do Tejo, em Portugal, é uma das mais importantes áreas húmidas para aves limícolas na rota Migratória do Atlântico Este. Desde 1975, foram efectuadas contagens anuais de aves limícolas no inverno nesta zona húmida e, em 2007, foi implementado um programa de monitorização mensal dos refúgios de preia-mar. As populações invernantes de três das cinco espécies de limícolas mais abundantes no estuário, o Pilrito-de-peito-preto Calidris alpina, a Tarambola-cinzenta Pluvialis squatarola e o Perna-vermelha Tringa totanus, mostraram tendências significativas de decréscimo nas últimas três décadas, potencialmente devido à degradação e perda de refúgios como resultado da crescente actividade antropogénica. Esta situação poderá deteriorar-se, uma vez que uma grande proporção das aves limícolas invernantes utiliza refúgios em áreas densamente urbanizadas sem qualquer estatuto legal de protecção. A utilização dos diferentes refúgios do estuário do Tejo por aves limícolas tem uma grande variação espacial e temporal, o que reforça a importância da existência de uma rede de refúgios de elevada qualidade nesta área húmida. Durante a migração, 60 a 80% das aves limícolas concentram-se num único refúgio, ficando assim particularmente vulneráveis neste período

Structural versus Electrical Functionalization of Oligo(phenyleneethynylene) Diamine Molecular Junctions

We explore both experimentally and theoretically the conductance and packing of molecular junctions based on oligo(phenyleneethynylene) (OPE) diamine wires, when a series of functional groups are incorporated into the wires. Using the scanning tunnelling microscopy break-junction (STM BJ) technique, we study these compounds in two environments (air and 1,2,4-trichlorobenzene) and explore different starting molecular concentrations. We show that the electrical conductance of the molecular junctions exhibits variations among different compounds, which are significant at standard concentrations but become unimportant when working at a low enough concentration. This shows that the main effect of the functional groups is to affect the packing of the molecular wires, rather than to modify their electrical properties. Our theoretical calculations consistently predict no significant changes in the conductance of the wires due to the electronic structure of the functional groups, although their ability to hinder ring rotations within the OPE backbone can lead to higher conductances at higher packing densities