114 research outputs found

    Vibrational properties of inclusion complexes: the case of indomethacin-cyclodextrin

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    Vibrational properties of inclusion complexes with cyclodextrins are studied by means of Raman spectroscopy and numerical simulation. In particular, Raman spectra of the non-steroidal, anti-inflammatory drug indomethacin undergo notable changes in the energy range between 1600 and 1700 cm−1^{-1} when inclusion complexes with cyclodextrins are formed. By using both \emph{ab initio} quantum chemical calculations and molecular dynamics, we studied how to relate such changes to the geometry of the inclusion process, disentangling single-molecule effects, from changes in the solid state structure or dimerization processes.Comment: 14 file figure

    Towards low-cost sodium-ion batteries: electrode behavior of graphite electrodes obtained from spheroidization waste fractions and their structure-property relations

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    Electrode materials for lithium-ion batteries (LIBs) typically show spherical particle shapes. For cathode materials, the spherical shape is obtained through the synthesis method. For graphite, the by far most popular anode material for LIBs, spherical particles are obtained through a spheroidization process. The yield of that process is quite low and limited to about 50%, leaving substantial amounts of by-products. Using such lower quality by-products would be quite attractive for developing low-cost energy stores like sodium-ion batteries (SIBs), for which the requirements for particle sizes and shapes might be less strict as compared to high performing LIBs. Here, we study three different graphite ‘waste fractions’ as anode material for SIBs that are obtained from the spheroidization process and how they compare to LIB battery grade material. Only negligible differences between the fractions are found when analyzing them with x-ray diffraction (XRD), Raman spectroscopy and elemental analysis (EA). More clear differences can be seen from N2 physisorption, scanning electron microscopy (SEM) and particle size analysis. For example, the surface areas of the ‘waste fractions’ can become roughly up to twice as large as compared to the battery grade fraction and the d 50 values shift by up to 11.9 ”m to lower numbers. Electrochemical measurements show that the ‘waste fractions’ can deliver the full electrode capacity and behave similar to the battery grade fraction up to 10 C. However, the higher surface areas lead to more irreversible losses in the first cycle. A surprising finding is that all graphite fractions show almost identical discharge voltages, while the charging voltages differ by as much as 200 mV. This asymmetric behavior only occurs in SIBs and not in LIBs, which indicates a more complex storage behavior in case of sodium.H2020 European Research Councilhttp://dx.doi.org/10.13039/100010663Bundesministerium fĂŒr Bildung und Forschunghttp://dx.doi.org/10.13039/501100002347Deutsche Forschungsgemeinschafthttp://dx.doi.org/10.13039/501100001659EIG Concert JapanPeer Reviewe

    Application of effect-based methods (EBMs) in a river basin: a preliminary study in Central Italy

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    Introduction. Effect-based methods (EBMs), i.e. in vitro and in vivo bioassays, represent innovative tools for the effect detection of environmental chemical pollutants on living organisms. The aim of this study was to evaluate the water quality of a river ecosystem implementing two in vivo bioassays on target freshwater animal species: the crustacean Daphnia magna and the small fish Danio rerio, also known as zebrafish.Materials and methods. The methods applied in this study, i.e. the Daphnia sp. Acute Immobilisation assay and the Fish Embryo Acute Toxicity (FET) test, are commonly used in water quality research and their application in short-term ecotoxicity detection is suggested by recent European projects. Two sampling sites were chosen in the urban part of the Tiber River in Rome, while a third one was chosen as a reference site in the Farfa River, a tributary upstream of the city. The sites in the Tiber River are potentially affected by different pollution sources, including urban and industrial wastewater discharges, the pesticide release, livestock waste products, and waste dumps.Results and discussion. The results of the study showed wide differences between the two applied bioassays. The FET test was generally more sensitive in detecting even low effects in all the water samples, but the strongest statistically results were observed with the D. magna Acute Immobilisation test. The results of this research confirm the effectiveness of EBMs in investigating and monitoring water chemical pollution, and stress the need for performing further studies, e.g. chemical analyses and other bioassays, to improve the knowledge of the health status of the Tiber River basin.Conclusions. Further results will aim to support the local authorities in adopting measures to reduce and to eliminate the sources of chemical pollution in the study area

    A comparative study of the actions of alkylpyridinium salts from a marine sponge and related synthetic compounds in rat cultured hippocampal neurones

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    BACKGROUND: Polymeric alkylpyridinium salts (poly-APS), are chemical defences produced by marine sponges including Reniera sarai. Poly-APS have previously been shown to effectively deliver macromolecules into cells. The efficiency of this closely follows the ability of poly-APS to form transient pores in membranes, providing strong support for a pore-based delivery mechanism. Recently, water soluble compounds have been synthesised that are structurally related to the natural polymers but bear a different number of pyridinium units. These compounds may share a number of bio-activities with poly-APS. Using electrophysiology, calcium imaging and 1,6-diphenyl-1,3,5-hexatriene imaging, the pore forming properties of poly-APS and four related synthetic oligomers have been tested on primary cultured rat hippocampal neurones. RESULTS: Acute application of poly-APS (0.5 ÎŒg/ml), reduced membrane potential, input resistance and suppressed action potential firing. Poly-APS evoked inward cation currents with linear current-voltage relationships similar to actions of pore formers on other cell types. Poly-APS (0.005–5 ÎŒg/ml) also produced Ca(2+ )transients in ~41% of neurones. The dose-dependence of poly-APS actions were complex, such that at 0.05 ÎŒg/ml and 5 ÎŒg/ml poly-APS produced varying magnitudes of membrane permeability depending on the order of application. Data from surface plasmon resonance analysis suggested accumulation of poly-APS in membranes and subsequent enhanced poly-APS binding. Even at 10–100 fold higher concentrations, none of the synthetic compounds produced changes in electrophysiological characteristics of the same magnitude as poly-APS. Of the synthetic oligomers tested compounds 1 (monomeric) and tetrameric 4 (5–50 ÎŒg/ml) induced small transient currents and 3 (trimeric) and 4 (tetrameric) produced significant Ca(2+ )transients in hippocampal neurones. CONCLUSION: Poly-APS induced pore formation in hippocampal neurones and such pores were transient, with neurones recovering from exposure to these polymers. Synthetic structurally related oligomers were not potent pore formers when compared to poly-APS and affected a smaller percentage of the hippocampal neurone population. Poly-APS may have potential as agents for macromolecular delivery into CNS neurones however; the smaller synthetic oligomers tested in this study show little potential for such use. This comparative analysis indicated that the level of polymerisation giving rise to the supermolecular structure in the natural compounds, is likely to be responsible for the activity here reported

    A comparative study of the actions of alkylpyridinium salts from a marine sponge and related synthetic compounds in rat cultured hippocampal neurones

    Get PDF
    Background: Polymeric alkylpyridinium salts (poly-APS), are chemical defences produced by marine sponges including Reniera sarai. Poly-APS have previously been shown to effectively deliver macromolecules into cells. The efficiency of this closely follows the ability of poly-APS to form transient pores in membranes, providing strong support for a pore-based delivery mechanism. Recently, water soluble compounds have been synthesised that are structurally related to the natural polymers but bear a different number of pyridinium units. These compounds may share a number of bio-activities with poly-APS. Using electrophysiology, calcium imaging and 1,6-diphenyl-1,3,5-hexatriene imaging, the pore forming properties of poly-APS and four related synthetic oligomers have been tested on primary cultured rat hippocampal neurones.Results: Acute application of poly-APS (0.5 ÎŒg/ml), reduced membrane potential, input resistance and suppressed action potential firing. Poly-APS evoked inward cation currents with linear current-voltage relationships similar to actions of pore formers on other cell types. Poly-APS (0.005-5 ÎŒg/ml) also produced Ca2+ transients in ∌41% of neurones. The dose-dependence of poly-APS actions were complex, such that at 0.05 ÎŒg/ml and 5 ÎŒg/ml poly-APS produced varying magnitudes of membrane permeability depending on the order of application. Data from surface plasmon resonance analysis suggested accumulation of poly-APS in membranes and subsequent enhanced poly-APS binding. Even at 10-100 fold higher concentrations, none of the synthetic compounds produced changes in electrophysiological characteristics of the same magnitude as poly-APS. Of the synthetic oligomers tested compounds 1 (monomeric) and tetrameric 4 (5-50 ÎŒg/ ml) induced small transient currents and 3 (trimeric) and 4 (tetrameric) produced significant Ca2+ transients in hippocampal neurones.Conclusion: Poly-APS induced pore formation in hippocampal neurones andsuch pores were transient, with neurones recovering from exposure to these polymers. Synthetic structurally related oligomers were not potent pore formers when compared to poly-APS and affected a smaller percentage of the hippocampal neurone population. Poly-APS may have potential as agents for macromolecular delivery into CNS neurones however; the smaller synthetic oligomers tested in this study show little potential for such use. This comparative analysis indicated that the level of polymerisation giving rise to the supermolecular structure in the natural compounds, is likely to be responsible for the activity here reported.</p

    Sirtuin 1 and 2 inhibitors enhance the inhibitory effect of sorafenib in hepatocellular carcinoma cells

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    Multidrug resistance (MDR) counteracts the efficiency of sorafenib, an important first-line therapy for hepatocellular carcinoma (HCC). Sirtuins (SIRTs) 1 and 2 are associated with tumor progression and MDR. We treated 2D and 3D cultures (which mimic the features of in vivo tumors) from HCC cells with sorafenib alone or in the presence of SIRTs 1 and 2 inhibitors (cambinol or EX-527; combined treatments). Cultures subjected to combined treatments showed a greater fall in cellular viability, proliferation (PCNA, cyclin D1 and Ki-67 expression and cell cycle analysis), migration and invasion when compared with cultures treated only with sorafenib. Similarly, combined treatments produced more apoptosis (annexin V/PI, caspase-3/7 activity) than sorafenib alone. Since cell cycle dysregulation and apoptotic blockage are reported mechanisms of MDR, the modulation found in PCNA, cyclin D1, Ki-67 and caspase-3/7 proteins by cambinol and EX-527 are probably playing a role in enhancing the sensitivity of HCC cell lines to sorafenib. EX-527 reduced MRP3 and BCRP expression in sorafenib-treated HCC cells. Since ABC transporters contribute to MDR, MRP3 and BCRP could be also influencing in the response of HCC cells to sorafenib. Overall, 2D and 3D cultures behave similarly except that 3D cultures were less sensitive to treatments, reinforcing the clinical relevance of the current study. Findings presented in this manuscript support a potential application for SIRTs 1 and 2 inhibitors since we demonstrated that these compounds enhance the inhibitory effect of sorafenib upon treatment of hepatocellular carcinoma cells lines.Fil: Ceballos Mancini, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Angel, Antonella. Universidad Nacional de Rosario; ArgentinaFil: Delprato, Carla Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Livore, Veronica Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Ferretti, Anabela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Ciencias Fisiológicas. Área Morfología; ArgentinaFil: Lucci, Alvaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Ciencias Fisiológicas. Área Morfología; ArgentinaFil: Comanzo, Carla Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Alvarez, María de Lujån. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Quiroga, Ariel Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Mottino, Aldo Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; ArgentinaFil: Carrillo, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Fisiología Experimental. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Fisiología Experimental; Argentin

    Highlights of the 1st Argentine Symposium of Young Bioinformatics Researchers (1SAJIB) organized by the ISCB RSG-Argentina

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    The 1st Argentine Symposium of Young Bioinformatics Researchers took place on 9-10 May 2016 at Universidad de Buenos Aires, Buenos Aires, Argentina. This event evolved from a previous meeting series known as Argentine Student Council Symposium that have been successfully organized since 2012 by the Regional Student Group of Argentina (RSG-Argentina). The change in name reflects the new vision of the organizing committee to gather together all students at Bachelor, Master and PhD levels, postdocs and researchers that are still not Principal Investigator. Here we summarize the main activities and outcomes from this year’s meeting and offer some insights into our future plans.Fil: Parra, Rodrigo Gonzalo. Max Planck Institute for Biophysical Chemistry; Alemania. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Defelipe, Lucas Alfredo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Guzovsky, Ana Brenda. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: MonzĂłn, Alexander. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂ­a; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Cravero, Fiorella. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Planta Piloto de IngenierĂ­a QuĂ­mica. Universidad Nacional del Sur. Planta Piloto de IngenierĂ­a QuĂ­mica; ArgentinaFil: Mancini, Estefania. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂ­micas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂ­micas de Buenos Aires; ArgentinaFil: Moreyra, NicolĂĄs Nahuel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de EcologĂ­a, GenĂ©tica y EvoluciĂłn de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de EcologĂ­a, GenĂ©tica y EvoluciĂłn de Buenos Aires; ArgentinaFil: Padilla Franzotti, Carla Luciana. Universidad Nacional de TucumĂĄn. Facultad de BioquĂ­mica, QuĂ­mica y Farmacia; ArgentinaFil: Revuelta, MarĂ­a Victoria. Cornell University; Estados Unidos. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Freiberger, Maria Ines. Universidad Nacional de Entre RĂ­os. Facultad de IngenierĂ­a; ArgentinaFil: Gonzalez, Nahuel H.. Universidad Nacional de Entre RĂ­os. Facultad de IngenierĂ­a; ArgentinaFil: Gonzalez, German Andres. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Diversidad y EcologĂ­a Animal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto de Diversidad y EcologĂ­a Animal; ArgentinaFil: Orts, Facundo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones BiolĂłgicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones BiolĂłgicas; ArgentinaFil: Stocchi, Nicolas. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones BiolĂłgicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones BiolĂłgicas; ArgentinaFil: Hasenahuer, Marcia AnahĂ­. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂ­a; ArgentinaFil: Teppa, Roxana Elin. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂ­micas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂ­micas de Buenos Aires; ArgentinaFil: Zea, Diego Javier. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂ­micas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂ­micas de Buenos Aires; ArgentinaFil: Palopoli, NicolĂĄs. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂ­micas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂ­micas de Buenos Aires; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂ­a; Argentin
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