472 research outputs found
Adsorption of malachite green and alizarin red s dyes using fe-btc metal organic framework as adsorbent
Synthetic organic dyes are widely used in various industrial sectors but are also among the most harmful water pollutants. In the last decade, significant efforts have been made to develop improved materials for the removal of dyes from water, in particular, on nanostructured adsorbent materials. Metal organic frameworks (MOFs) are an attractive class of hybrid nanostructured materials with an extremely wide range of applications including adsorption. In the present work, an iron-based Fe-BTC MOF, prepared according to a rapid, aqueous-based procedure, was used as an adsorbent for the removal of alizarin red S (ARS) and malachite green (MG) dyes from water. The synthesized material was characterized in detail, while the adsorption of the dyes was monitored by UV-Vis spectroscopy. An optimal adsorption pH of 4, likely due to the establishment of favor-able interactions between dyes and Fe-BTC, was found. At this pH and at a temperature of 298 K, adsorption equilibrium was reached in less than 30 min following a pseudo-second order kinetics, with kâ of 4.29 Ă 10â3 and 3.98 Ă 10â2 gâmgâ1 minâ1 for ARS and MG, respectively. The adsorption isotherm followed the Langmuir model with maximal adsorption capacities of 80 mgâgâ1 (ARS) and 177 mgâgâ1 (MG), and KL of 9.30â103 Lâmgâ1 (ARS) and 51.56â103 Lâmgâ1 (MG)
Increased shedding of soluble fragments of P-cadherin in nipple aspirate fluids from women with breast cancer.
Breast cancer, a worldwide disease with increasing incidence, develops from ductal/lobular epithelium. Nipple aspirate fluid (NAF), secreted from the breast ducts and lobules, can be analyzed to assess breast metabolic activity. P-cadherin is frequently over-expressed in high-grade invasive breast carcinomas and has been reported to be an enhancer of migration and invasion of breast cancer cells, being correlated with tumor aggressiveness. The present study analyzed the soluble fragment of P-cadherin in milk, NAF and matched plasma samples of healthy subjects and in women with precancer conditions and breast cancer. Soluble P-cadherin was detected in all plasma and milk samples, and in about 31.3% of NAF samples. The lowest levels of soluble P-cadherin were found in plasma, with no significant difference among NoCancer, PreCancer and Cancer patients. The highest concentration of soluble P-cadherin was detected in milk collected during the first trimester of lactation, significantly with respect to all NAF samples. There were significantly higher levels of soluble P-cadherin in NAF from Cancer patients than those in women with NoCancer and PreCancer (P < 0.0001). Although no significant difference was found between in situ and invasive breast cancer, soluble P-cadherin levels were found at high concentrations in c-erbB-2-positive tumors, showing a positive correlation with disease stage grouping and tumor grade, and an inverse relationship with estrogen/progesterone receptor status. High levels of the soluble fragment of P-cadherin in Cancer NAF suggest its possible release via proteolytic processing, favoring cancer cell detachment from breast duct, and suggesting that measuring soluble P-cadherin in NAF may improve the identification of women with increased breast cancer risk
Implementing the âBest Template Searchingâ tool into Adenosiland platform
Background: Adenosine receptors (ARs) belong to the G protein-coupled receptors (GCPRs) family. The recent release of X-ray structures of the human A2A AR (h A2A AR ) in complex with agonists and antagonists has increased the application of structure-based drug design approaches to this class of receptors. Among them, homology modeling represents the method of choice to gather structural information on the other receptor subtypes, namely A1, A2B, and A3 ARs. With the aim of helping users in the selection of either a template to build its own models or ARs homology models publicly available on our platform, we implemented our web-resource dedicated to ARs, Adenosiland, with the âBest Template Searchingâ facility. This tool is freely accessible at the following web address: http://mms.dsfarm.unipd.it/Adenosiland/ligand.php.
Findings: The template suggestions and homology models provided by the âBest Template Searchingâ tool are guided by the similarity of a query structure (putative or known ARs ligand) with all ligands co-crystallized with hA2A AR subtype. The tool computes several similarity indexes and sort the outcoming results according to the index selected by the user.
Conclusions: We have implemented our web-resource dedicated to ARs Adenosiland with the âBest Template Searchingâ facility, a tool to guide template and models selection for hARs modelling. The underlying idea of our new facility, that is the selection of a template (or models built upon a template) whose co-crystallized ligand shares the highest similarity with the query structure, can be easily extended to other GPCRs
Assessing the effects of adding Timberland and Farmland into resource-based Sovereign Wealth Fund portfolios
Sovereign Wealth Funds (SWFs) have been prompted to reconsider their traditional asset allocations given
the underperformance of equity markets post-2008 financial crisis and the collapse of commodity prices in
recent years. Timberland and farmland investments are increasingly attracting the attention of these funds,
seeking higher and more stable returns and means to hedge commodity risk. However, analytical analyses
on the effect of these investments to SWFs are still limited. This paper studies the effects of including
timber and farmland investments in the strategic asset allocation (SAA) of an oil-based SWF. We model the
portfolio of investment of an SWF using Norwayâs Government Pension Fund Global as a case study, and
gathering empirical data for the period Q1 2007 - Q1 2016. We examine how allocations in timberland and
farmland affect returns, the fundâs net growth, and the portfolio exposure to commodity risk. Our results
indicate that timber and farmland bring positive effects when supplanting equity investments, improve the
return-risk characteristic of the portfolio, and provide hedging again oil risk
Interaction of plant amine oxidases with diaminoethers
Polyamines are ubiquitous compounds, which are involved in crucial physiological events
including cell growth and differentiation. The catabolic oxidative degradation of polyamines is
catalyzed by quinoprotein copper-containing amine oxidases (CAOs) and flavoprotein
polyamine oxidases (PAOs). Various synthetic polyamine analogs and polyamine derivatives
have been reported, which represent important tools (substrates or inhibitors) in the study of
catalytic properties of the enzymes. In this work, two related compounds were studied in the
reactions with plant amine oxidases: 1,8-diamino-3,6-dioxaoctane (DADO) and 1,10-bis(2-
pyridinylmethyl)-4,7-dioxa-1,10-diazadecane (BPDD). Based on activity and stoichiometry
assays together with spectrophotometric measurements, DADO can be considered a good
substrate for grass pea, lentil and E. characias CAOs with Km values in the range 10-4 â 10-3 M.
Its oxidative degradation produces the corresponding aminoaldehyde 8-amino-3,6-dioxaoctanal,
which does not undergo spontaneous cyclization (as it is known for the oxidation products of
natural substrates putrescine, cadaverine and spermidine) or polymerization in the reaction
mixture. Conversely, oat PAO does not oxidize DADO and is only weakly inhibited by the
compound (Ki = 1.6 mM towards putrescine). BPDD was found to be a competitive inhibitor of
both CAOs and PAOs with Ki values of 10-4 M. DADO could be suggested as a potential affinity
ligand for CAOs
Macromolecular-scale resolution in biological fluorescence microscopy
We demonstrate far-field fluorescence microscopy with a focal-plane resolution of 15â20 nm in biological samples. The 10- to 12-fold multilateral increase in resolution below the diffraction barrier has been enabled by the elimination of molecular triplet state excitation as a major source of photobleaching of a number of dyes in stimulated emission depletion microscopy. Allowing for relaxation of the triplet state between subsequent excitationâdepletion cycles yields an up to 30-fold increase in total fluorescence signal as compared with reported stimulated emission depletion illumination schemes. Moreover, it enables the reduction of the effective focal spot area by up to â140-fold below that given by diffraction. Triplet-state relaxation can be realized either by reducing the repetition rate of pulsed lasers or by increasing the scanning speed such that the build-up of the triplet state is effectively prevented. This resolution in immunofluorescence imaging is evidenced by revealing nanoscale protein patterns on endosomes, the punctuated structures of intermediate filaments in neurons, and nuclear protein speckles in mammalian cells with conventional optics. The reported performance of diffraction-unlimited fluorescence microscopy opens up a pathway for addressing fundamental problems in the life sciences
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