64 research outputs found

    Removal of ciprofloxacin from aqueous solutions using pillared clays

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    Emerging contaminants in the environment have caused enormous concern in the last few decades, and among them, antibiotics have received special attention. On the other hand, adsorption has shown to be a useful, low-cost, and eco-friendly method for the removal of this type of contaminants from water. This work is focused on the study of ciprofloxacin (CPX) removal from water by adsorption on pillared clays (PILC) under basic pH conditions, where CPX is in its anionic form (CPX-). Four different materials were synthetized, characterized, and studied as adsorbents of CPX (Al-, Fe-, Si-, and Zr-PILC). The highest CPX adsorption capacities of 100.6 and 122.1 mg g-1 were obtained for the Si- and Fe-PILC (respectively), and can be related to the porous structure of the PILCs. The suggested adsorption mechanism involves inner-sphere complexes formation as well as van der Waals interactions between CPX- and the available adsorption sites on the PILC surfaces.Fil: Roca Jalil, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Baschini, Miria Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemåticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

    Importance of the αs-plot Method in Characterization of Nanoporous Materials

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    In this work, an exhaustive study of the calculation of micropore and mesopore volumes with αs-plot method as proposed by Professor Sing is carried out. The method is critically compared with other similar methods such as the Dubinin–Radushkevich, t-plot and those based on density functional theory (DFT). For comparison purposes, several nanoporous materials with different chemical properties were selected. The analysis was segregated into three categories: (i) microporous materials, in which the analyzed samples are activated carbons (ACs) with different pore-size distributions, a single-walled carbon nanotube (SWNT) and a zeolite (MS5A); (ii) mesoporous materials, including ordered mesoporous carbons (CMK-3) and ordered mesoporous siliceous materials (MCM-41 and SBA-15); and (iii) micro-mesoporous materials, in which pillared clays (PILCs) obtained with different metals (Al, Si, Fe and Zr) were studied. To apply the αs-plot method, several standard isotherms previously reported by other authors were considered for the analysis of microporous and mesoporous materials. Furthermore, a series of four reference materials for PILCs were synthesized and their high-resolution nitrogen adsorption isotherms were measured and reported. The results obtained by the αs-plot method are consistent with those obtained by DFT methods. This consistency highlights the importance of the use of this reliable and versatile method, where the correct selection of the standard isotherm is the most critical aspect to be considered.Fil: Villarroel Rocha, Jhonny. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto de FĂ­sica Aplicada; ArgentinaFil: Barrera Diaz, Deicy Amparo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto de FĂ­sica Aplicada; ArgentinaFil: Garcia Blanco, Andres Alberto. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto de FĂ­sica Aplicada; ArgentinaFil: Roca Jalil, MarĂ­a Eugenia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto de FĂ­sica Aplicada; ArgentinaFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto de FĂ­sica Aplicada; Argentin

    Mechanical strain stimulates COPII‐dependent secretory trafficking via Rac1

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    Cells are constantly exposed to various chemical and physical stimuli. While much has been learned about the biochemical factors that regulate secretory trafficking from the endoplasmic reticulum (ER), much less is known about whether and how this trafficking is subject to regulation by mechanical signals. Here, we show that subjecting cells to mechanical strain both induces the formation of ER exit sites (ERES) and accelerates ER‐to‐Golgi trafficking. We found that cells with impaired ERES function were less capable of expanding their surface area when placed under mechanical stress and were more prone to develop plasma membrane defects when subjected to stretching. Thus, coupling of ERES function to mechanotransduction appears to confer resistance of cells to mechanical stress. Furthermore, we show that the coupling of mechanotransduction to ERES formation was mediated via a previously unappreciated ER‐localized pool of the small GTPase Rac1. Mechanistically, we show that Rac1 interacts with the small GTPase Sar1 to drive budding of COPII carriers and stimulates ER‐to‐Golgi transport. This interaction therefore represents an unprecedented link between mechanical strain and export from the ER

    Algas de Copahue: Estudios preliminares

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    El sistema termal Copahue se encuentra ubicado en la provincia de NeuquĂ©n sobre la cordillera de los Andes a aproximadamente 1900 metros sobre el nivel del mar y al pie del volcĂĄn Copahue (Lonac, 2017). Cada temporada, unos 20 mil pacientes se trasladan al complejo para recibir tratamientos diversos con fangos, vapores y aguas que contribuyen a mejorar su estado de salud (Monasterio y Grenovero, 2008; Ubogui et al., 2008). El sistema termal cuenta con diferentes lagunas, entre ellas, las Lagunas Sulfurosa, del Chancho, Verde, de los Callos y de las Algas cuyas aguas difieren entre sĂ­ por sus propiedades fisicoquĂ­micas. En lĂ­neas generales, estas propiedades se encuentran asociadas al nivel de mineralizaciĂłn que presentan y el tipo de dolencias que con ellas pueden tratarse (Monasterio, 2008). Existe una importante cantidad de estudios dedicados a la caracterizaciĂłn de los fangos y las aguas mineromedicinales de estas lagunas, pero proporcionalmente mucho menos es lo que se conoce, a travĂ©s de publicaciones cientĂ­ficas, acerca de las propiedades asociadas a las microalgas y los componentes con potencial uso terapĂ©utico derivados de ellas (Armijo et al, 2008; Monasterio, 2008; Baschini et al., 2010; Baschini et al., 2017; Gurnik, 2017; Vela, 2017). En particular las Lagunas Verde, de los Callos y las Algas son los sistemas con mayor presencia detectable de microalgas a simple vista. De estos sistemas, la Laguna Verde ha sido la mĂĄs estudiada de forma tal que se sabe que el peloide que de ella se obtiene, presenta un alto contenido de materia orgĂĄnica y sus aguas son hipotermales, con bajo contenido de azufre y pH neutro o levemente ĂĄcido (Baschini et al., 2010; Baschini et al., 2017). No obstante, la laguna debe su nombre y sus caracterĂ­sticas justamente a la presencia de microalgas clorofitas, entre ellas Chlorella Kessleri segĂșn lo reportado por Accorinti (1996). Este gĂ©nero fue objeto de numerosos estudios sobre la producciĂłn de compuestos bioactivos que evidenciaron que ciertas especies liberan sustancias con propiedades antibacterianas y/o antifĂșngicas al medio circundante (Accorinti y Rodriguez 1988; Burkiewicz y Synak 1996; JuĂĄrez y Accorinti 1995).Ante lo expuesto, en el presente trabajo se realizĂł un estudio preliminar de las propiedades de agua y fango extraĂ­dos de la Laguna de las Algas comparativamente con dos fangos y aguas conocidos como las Lagunas Verde y del Chancho. El objetivo principal a largo plazo, serĂĄ buscar evidencias de la posible presencia de microalgas y tratar de dilucidar el funcionamiento de estos sistemas en la bĂșsqueda de aislar metabolitos con potenciales aplicaciones tanto en la formulaciĂłn de aguas y fangos de tratamiento como en la industria farmacĂ©utica.Fil: Sanchez, Micaela Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas. Universidad Nacional del Comahue. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas; Argentina. Universidad Nacional del Comahue. Facultad de IngenierĂ­a. Departamento de QuĂ­mica; ArgentinaFil: Roca Jalil, MarĂ­a Eugenia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas. Universidad Nacional del Comahue. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas; Argentina. Universidad Nacional del Comahue. Facultad de IngenierĂ­a. Departamento de QuĂ­mica; ArgentinaFil: Gurnik, Nicolas. Gobierno de la Provincia del Neuquen. Ministerio de Desarrollo Territorial. Ente Provincial de Termas del Neuquen.; ArgentinaFil: Vela, Lorena. Gobierno de la Provincia del Neuquen. Ministerio de Desarrollo Territorial. Ente Provincial de Termas del Neuquen.; ArgentinaFil: Gramisci, Betina RocĂ­o. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas. Universidad Nacional del Comahue. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas; ArgentinaFil: Sette, Paula Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas. Universidad Nacional del Comahue. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas; ArgentinaFil: Barbagelata, RaĂșl Jorge. Universidad Nacional del Comahue. Facultad de IngenierĂ­a. Departamento de QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas. Universidad Nacional del Comahue. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas; ArgentinaFil: Baschini, Miria Teresita. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas. Universidad Nacional del Comahue. Instituto de InvestigaciĂłn y Desarrollo en IngenierĂ­a de Procesos, BiotecnologĂ­a y EnergĂ­as Alternativas; Argentina. Universidad Nacional del Comahue. Facultad de IngenierĂ­a. Departamento de QuĂ­mica; ArgentinaVI Congreso Iberoamericano de PeloidesCopahueArgentinaUniversidad Nacional del ComahueSociedad Española de HidrologĂ­a MĂ©dicaGobierno de la Provincia del Neuquen. Ministerio de Desarrollo Territorial. Ente Provincial de Termas del NeuquenSociedad Iberoamericana de Peloide

    The cooking task: making a meal of executive functions

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    Current standardized neuropsychological tests may fail to accurately capture real-world executive deficits. We developed a computer-based Cooking Task (CT) assessment of executive functions and trialed the measure with a normative group before use with a head-injured population. Forty-six participants completed the computerized CT and subtests from standardized neuropsychological tasks, including the Tower and Sorting Tests of executive function from the Delis-Kaplan Executive Function System (D-KEFS) and the Cambridge prospective memory test (CAMPROMPT), in order to examine whether standardized executive function tasks, predicted performance on measurement indices from the CT. Findings showed that verbal comprehension, rule detection and prospective memory contributed to measures of prospective planning accuracy and strategy implementation of the CT. Results also showed that functions necessary for cooking efficacy differ as an effect of task demands (difficulty levels). Performance on rule detection, strategy implementation and flexible thinking executive function measures contributed to accuracy on the CT. These findings raise questions about the functions captured by present standardized tasks particularly at varying levels of difficulty and during dual-task performance. Our preliminary findings also indicate that CT measures can effectively distinguish between executive function and Full Scale IQ abilities. Results of the present study indicate that the CT shows promise as an ecologically valid measure of executive function for future use with a head-injured population and indexes selective executive function’s captured by standardized tests

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
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