125 research outputs found

    Adsorption of malachite green and alizarin red s dyes using fe-btc metal organic framework as adsorbent

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    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 k” of 4.29 × 10−3 and 3.98 × 10−2 g∙mg−1 min−1 for ARS and MG, respectively. The adsorption isotherm followed the Langmuir model with maximal adsorption capacities of 80 mg∙g−1 (ARS) and 177 mg∙g−1 (MG), and KL of 9.30∙103 L∙mg−1 (ARS) and 51.56∙103 L∙mg−1 (MG)

    Confirming the function of a Final Bronze Age wine processing site in the Nuraghe Genna Maria in Villanovaforru (South Sardinia)

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    The stone artefact in the hut γ of the NuragheGenna Maria, object of this study, is part of a compound still unpublished today and dated to the Nuragic period. It was found during a 1991 excavation, revealing a situation unchanged since the collapse occurred between the 10th and 9th century B.C., thus preserving the situation at the time of the collapse to this day. The presence of tartaric acid - the marker considered to determinate the presence of wines or products deriving from grapes - has been determined using HPLC-DAD and UHPLC-HQOMS. So the findings under examination, together with the overall evaluation of the archaeological aspects examined, suggests to positively consider the stone artifact as a "laccus" (the latin word for wine presses, still used in the Sardinian language today ) for grape crushing. The internal slope of the floor of the "laccus" allowed the extraction of juice with rapid separation of juice from berry skins. The presence in Sardinia of a large number of "stone wine presses" ("palmenti" in Italian) such as that of the Nuraghe Genna Maria studied in this article, brings a contribution to their dating and confirm the existence of an oenological industry on the island in the Archaic period (9th-10th century B.C.)

    Dynamic regulation of airway surface liquid pH by TMEM16A and SLC26A4 in cystic fibrosis nasal epithelia with rare mutations

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    In cystic fibrosis (CF), defects in the CF transmembrane conductance regulator (CFTR) channel lead to an acidic airway surface liquid (ASL), which compromises innate defence mechanisms, predisposing to pulmonary failure. Restoring ASL pH is a potential therapy for people with CF, particularly for those who cannot benefit from current highly effective modulator therapy. However, we lack a comprehensive understanding of the complex mechanisms underlying ASL pH regulation. The calcium-activated chloride channel, TMEM16A, and the anion exchanger, SLC26A4, have been proposed as targets for restoring ASL pH, but current results are contradictory and often utilise nonphysiological conditions. To provide better evidence for a role of these two proteins in ASL pH homeostasis, we developed an efficient CRISPR-Cas9-based approach to knock-out (KO) relevant transporters in primary airway basal cells lacking CFTR and then measured dynamic changes in ASL pH under thin-film conditions in fully differentiated airway cultures, which better simulate the in vivo situation. Unexpectantly, we found that both proteins regulated steady-state as well as agonist-stimulated ASL pH, but only under inflammatory conditions. Furthermore, we identified two Food and Drug Administration (FDA)-approved drugs which raised ASL pH by activating SLC26A4. While we identified a role for SLC26A4 in fluid absorption, KO had no effect on cyclic adenosine monophosphate (cAMP)-stimulated fluid secretion in airway organoids. Overall, we have identified a role of TMEM16A in ASL pH homeostasis and shown that both TMEM16A and SLC26A4 could be important alternative targets for ASL pH therapy in CF, particularly for those people who do not produce any functional CFTR

    The SLC26A9 inhibitor S9‐A13 provides no evidence for a role of SLC26A9 in airway chloride secretion but suggests a contribution to regulation of ASL pH and gastric proton secretion

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    The solute carrier 26 family member A9 (SLC26A9) is an epithelial anion transporter that is assumed to contribute to airway chloride secretion and surface hydration. Whether SLC26A9 or CFTR is responsible for airway Cl− transport under basal conditions is still unclear, due to the lack of a specific inhibitor for SLC26A9. In the present study, we report a novel potent and specific inhibitor for SLC26A9, identified by screening of a drug-like molecule library and subsequent chemical modifications. The most potent compound S9-A13 inhibited SLC26A9 with an IC50 of 90.9 ± 13.4 nM. S9-A13 did not inhibit other members of the SLC26 family and had no effects on Cl− channels such as CFTR, TMEM16A, or VRAC. S9-A13 inhibited SLC26A9 Cl− currents in cells that lack expression of CFTR. It also inhibited proton secretion by HGT-1 human gastric cells. In contrast, S9-A13 had minimal effects on ion transport in human airway epithelia and mouse trachea, despite clear expression of SLC26A9 in the apical membrane of ciliated cells. In both tissues, basal and stimulated Cl− secretion was due to CFTR, while acidification of airway surface liquid by S9-A13 suggests a role of SLC26A9 for airway bicarbonate secretion

    The Cycle of Earnings Inequality: Evidence from Spanish Social Security Data

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    The emerging role of AMPK in the regulation of breathing and oxygen supply

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    Regulation of breathing is critical to our capacity to accommodate deficits in oxygen availability and demand during, for example, sleep and ascent to altitude. It is generally accepted that a fall in arterial oxygen increases afferent discharge from the carotid bodies to the brainstem and thus delivers increased ventilatory drive, which restores oxygen supply and protects against hypoventilation and apnoea. However, the precise molecular mechanisms involved remain unclear. We recently identified as critical to this process the AMP-activated protein kinase (AMPK), which is key to the cell-autonomous regulation of metabolic homoeostasis. This observation is significant for many reasons, not least because recent studies suggest that the gene for the AMPK-α1 catalytic subunit has been subjected to natural selection in high-altitude populations. It would appear, therefore, that evolutionary pressures have led to AMPK being utilized to regulate oxygen delivery and thus energy supply to the body in the short, medium and longer term. Contrary to current consensus, however, our findings suggest that AMPK regulates ventilation at the level of the caudal brainstem, even when afferent input responses from the carotid body are normal. We therefore hypothesize that AMPK integrates local hypoxic stress at defined loci within the brainstem respiratory network with an index of peripheral hypoxic status, namely afferent chemosensory inputs. Allied to this, AMPK is critical to the control of hypoxic pulmonary vasoconstriction and thus ventilation–perfusion matching at the lungs and may also determine oxygen supply to the foetus by, for example, modulating utero-placental blood flow

    Antiche e moderne tecnologie: l’applicazione delle tecniche di rilevamento tridimensionale per la rappresentazione e l’analisi dei manufatti litici

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    In the past few years, the application of digital techniques to archaeology has strongly increased, including 3D recording of lithic artefacts for purposes of documentation and analysis. In this paper, the main acquisition techniques are reviewed focusing on their application to lithics, and on the cost-benefit analysis which largely depends on the research objectives. The introduction of the main functions of the virtual approaches to lithics comes from the new possibilities offered in the area of graphic documentation. In fact, 3D models could gradually replace the archaeological drawing thanks to the data objectivity and to the ability to undergo remote analysis. Indeed, in virtual models complex metric data and technological information are easily recorded. Furthermore, 3D models allow the application of quantitative and statistical analysis for different aims, such as reduction intensity estimation and geometric morphometrics, especially thanks to the landmark-based approach. All these potentials have been already explored in recent years, some of them have produced a considerable number of publications. However, this diversification needs the sharing of Open Data protocols in order to evaluate the methods, as well as the application of integrated approaches. Some examples of integration between traditional and 3D analyses derive from traceology and refitting studies, where the virtual tool is not considered as replacing but complementary. Finally, the options in the fields of data storage and cataloguing have been addressed, besides the free circulation of 3D models for academic and museological purposes, including 3D printing

    Lashed by the wind: short-term Middle Palaeolithic occupations within the loess-palaeosoil sequence at Monte Netto (Northern Italy)

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    The final Middle Palaeolithic of northern Italy is almost exclusively known based on pluristratified sites in caves or rock shelter, which attest a certain technological variability within the Mousterian through the adoption of different knapping methods focused on the production of flakes or blades. The almost total lack of specialized and/or short-term open-air sites framed at this stage contributes to create a fragmentary and incomplete picture with regard to the last Neanderthal occupation of the area. For this reason, the Monte Netto site, an isolated hill at the northern margin of the Po Plain and at the foot of the Prealps, represents a key deposit to investigate this phase. Along the loess-palaeosoil sequence, investigated from a geochronological and pedological point of view, frequentations by Mousterian Neanderthal groups are attested at two different times, of which the most consistent is: associated to sediments dated to 44,400 +/- 5.4 ky BP. The findings confirm the sporadic frequentation of marginal open areas during the cold, arid and highly fluctuating climate of the MIS 3, providing a more complete picture of the human occupation along the Po Plain Loess Basin (PPLB). An interregional comparison points out the clear intention, by the last Neanderthal groups of the Po Plain, of producing elongated supports by applying different methods, within a varied and organized system of resources exploitation evidenced by the selection of raw materials coming from more than 60 km.The final Middle Palaeolithic of northern Italy is almost exclusively known based on pluristratified sites in caves or rock shelter, which attest a certain technological variability within the Mousterian through the adoption of different knapping methods focused on the production of flakes or blades. The almost total lack of specialized and/or short-term open-air sites framed at this stage contributes to create a fragmentary and incomplete picture with regard to the last Neanderthal occupation of the area. For this reason, the Monte Netto site, an isolated hill at the northern margin of the Po Plain and at the foot of the Prealps, represents a key deposit to investigate this phase. Along the loess-palaeosoil sequence, investigated from a geochronological and pedological point of view, frequentations by Mousterian Neanderthal groups are attested at two different times, of which the most consistent is dated to 44,400 ± 5.4 ky BP. The findings confirm the sporadic frequentation of marginal open areas during the cold, arid and highly fluctuating climate of the MIS 3, providing a more complete picture of the human occupation along the Po Plain Loess Basin (PPLB). An interregional comparison points out the clear intention, by the last Neanderthal groups of the Po Plain, of producing elongated supports by applying different methods, within a varied and organized system of resources exploitation evidenced by the selection of raw materials coming from more than 60 km

    Grotta di Sant’Angelo (Lizzano, Taranto)

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    La grotta di Sant’Angelo è situata all’estremità sudorientale della Murgia tarantina, circa 2 km a nord-ovest del paese di Lizzano. La cavità si apre sulla sommità di una collina formata da calcari bianchi del Cretacico ed ha uno sviluppo in estensione di circa 50 metri. La situazione attuale in cui versa la Grotta è delicata, in quanto è evidente la necessità di diversi interventi: l’ingresso alla cavità è aperto ed ostruito dalla vegetazione; inoltre, l’apertura principale ed un’apertura circolare sulla volta posta nel mezzo della cavità sono state utilizzate, negli ultimi decenni, per lo scarico di pietre e rifiuti. L’importanza storico-archeologica della cavità si evince dai reperti che si ritrovano in superficie e dai resti straordinari di pitture sacre che adornano le pareti. In particolare, nella zona dell’entrata principale, sotto alle pietre di riporto è visibile un deposito compatto a grana più fine da cui emergono ossa animali fortemente disidratate e ad uno stadio avanzato di fossilizzazione. Dato il livello di conservazione di questi resti, il deposito è molto antico e risale al Pleistocene e al Paleolitico medi
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