109 research outputs found

    Nanofibrous Online Solid-Phase Extraction Coupled with Liquid Chromatography for the Determination of Neonicotinoid Pesticides in River Waters

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    Polymeric nano- and microfibers were tested as potential sorbents for the extraction of five neonicotinoids from natural waters. Nanofibrous mats were prepared from polycaprolactone, polyvinylidene fluoride, polystyrene, polyamide 6, polyacrylonitrile, and polyimide, as well as microfibers of polyethylene, a polycaprolactone nano- and microfiber conjugate, and polycaprolactone microfibers combined with polyvinylidene fluoride nanofibers. Polyimide nanofibers were selected as the most suitable sorbent for these analytes and the matrix. A Lab-In-Syringe system enabled automated preconcentration via online SPE of large sample volumes at low pressure with analyte separation by HPLC. Several mat layers were housed in a solvent filter holder integrated into the injection loop of an HPLC system. After loading 2 mL sample on the sorbent, the mobile phase eluted the retained analytes onto the chromatographic column. Extraction efficiencies of 68.8-83.4% were achieved. Large preconcentration factors ranging from 70 to 82 allowed reaching LOD and LOQ values of 0.4 to 1.7 and 1.2 to 5.5 mu g center dot L-1, respectively. Analyte recoveries from spiked river waters ranged from 53.8% to 113.3% at the 5 mu g center dot L-1 level and from 62.8% to 119.8% at the 20 mu g center dot L-1 level. The developed methodology proved suitable for the determination of thiamethoxam, clothianidin, imidacloprid, and thiacloprid, whereas matrix peak overlapping inhibited quantification of acetamiprid.STARSS project - ERDF CZ.02.1.01/0.0/0.0/15_003/0000465Grant Agency of the Czech Republic 20-19297SSpanish Government RED2018-102522-TDivision of Analytical Chemistry of the European Chemical SocietyProject Junta de Andalucia-Programa Operativo FEDER B-AGR-202-UGR2

    Vinyl sulfonyl chemistry-driven unidirectional transport of a macrocycle through a [2]rotaxane

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    This work has been financially supported by FEDER(EDRF)/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (P18-FR-2877), grant PID2020-112906GA-I00 funded by MCIN/AIE (/10.13039/501100011033) and Ministerio de Economia y Competitividad (MINECO, Spain) (CTQ2014-55474-C2-2-R and CTQ2017-86125P, co-financed by FEDER funds). Funding for open access APCs provided by Universidad de Granada through a Paid by Read & Publish agreement with RSC.By applying a combination of the coupling-and-decoupling (CAD) chemistry of the vinyl sulfonate group with the click thia-Michael addition to the vinyl sulfone group (MAVS) we performed the irreversible unidirectional transportation of the ring through the linear component in a [2]rotaxane by a chemically and pH-driven flashing energy ratchet mechanism. The design is based on a monostoppered thread precursor bearing a sulfonate stopper, a vinyl sulfone group on the unstoppered end and a dibenzylammonium unit as recognition site for the dibenzo-24-crown-8 macrocycle. First, the ring enters from the vinyl sulfone side and the rotaxane is capped through a thia-Michael addition reaction. Then, the cleavage of the sulfonate group of the opposite stopper using MgBr2 as chemical stimulus and subsequent addition of base (Et3N) promoted the controlled and directional release of the macrocycle into the bulk under mild conditions. The efficiency of the system allowed the in situ operation as demonstrated by NMR and HRMS techniques.FEDER(EDRF)/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades - MCIN/AIE P18-FR-2877Ministerio de Economia y Competitividad (MINECO, Spain) (FEDER funds) CTQ2014-55474-C2-2-R; CTQ2017-86125PUniversidad de GranadaRSCMCIN/AIE PID2020-112906GA-I0

    Shift in social media app usage during covid-19 lockdown and clinical anxiety symptoms: Machine learning-based ecological momentary assessment study

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    Background: Anxiety symptoms during public health crises are associated with adverse psychiatric outcomes and impaired health decision-making. The interaction between real-time social media use patterns and clinical anxiety during infectious disease outbreaks is underexplored. Objective: We aimed to evaluate the usage pattern of 2 types of social media apps (communication and social networking) among patients in outpatient psychiatric treatment during the COVID-19 surge and lockdown in Madrid, Spain and their short-term anxiety symptoms (7-item General Anxiety Disorder scale) at clinical follow-up. Methods: The individual-level shifts in median social media usage behavior from February 1 through May 3, 2020 were summarized using repeated measures analysis of variance that accounted for the fixed effects of the lockdown (prelockdown versus postlockdown), group (clinical anxiety group versus nonclinical anxiety group), the interaction of lockdown and group, and random effects of users. A machine learning–based approach that combined a hidden Markov model and logistic regression was applied to predict clinical anxiety (n=44) and nonclinical anxiety (n=51), based on longitudinal time-series data that comprised communication and social networking app usage (in seconds) as well as anxiety-associated clinical survey variables, including the presence of an essential worker in the household, worries about life instability, changes in social interaction frequency during the lockdown, cohabitation status, and health status. Results: Individual-level analysis of daily social media usage showed that the increase in communication app usage from prelockdown to lockdown period was significantly smaller in the clinical anxiety group than that in the nonclinical anxiety group (F1,72=3.84, P=.05). The machine learning model achieved a mean accuracy of 62.30% (SD 16%) and area under the receiver operating curve 0.70 (SD 0.19) in 10-fold cross-validation in identifying the clinical anxiety group. Conclusions: Patients who reported severe anxiety symptoms were less active in communication apps after the mandated lockdown and more engaged in social networking apps in the overall period, which suggested that there was a different pattern of digital social behavior for adapting to the crisis. Predictive modeling using digital biomarkers—passive-sensing of shifts in category-based social media app usage during the lockdown—can identify individuals at risk for psychiatric sequelae.JR was supported by the American Psychiatric Association 2021 Junior Psychiatrist Research Colloquium (NIDA R-13 grant). ES received funding from the European Union Horizon 2020 research and innovation program (Marie Sklodowska-Curie grant 813533). AA is supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (RTI2018-099655-B-I00), the Comunidad de Madrid (Y2018/TCS-4705 PRACTICO-CM), and the BBVA Foundation (Deep-DARWiN grant)

    Producción de biogás: incidencia del ph inicial en procesos de digestión anaeróbica

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    En este trabajo se ensayaron distintas soluciones buffer para optimizar la producción de biogás en codigestión anaeróbica de residuos de cebolla y estiércol vacuno. Se realizaron mediciones de pH, volumen generado de biogás, Ácidos Grasos Volátiles (AVG) y alcalinidad con el fin de correlacionar estos parámetros con la producción de biogás. De las distintas soluciones probadas, se presentan las que han mostrado mejores resultados en relación con la generación de biogás. La solución buffer NH4Cl- NH4OH produce un 50 % más de biogás que con la que contiene P (H6NO4P) , lo que se refleja en la evolución del pH, y los AVG, ya que en el reactor con baja producción de biogás el pH baja a valores indeseables hasta la acidificación del mismo (5,76), y se produce una acumulación de AVG hasta 5.100 mg/L.Batch experiments were carried out to test some buffer solutions in order to optimize biogas production by anaerobic codigestion of onion wastes and cow manure. The results of batch experiments showed pH, VFA (volatile fatty acids), and alkalinity trends, regarding biogas production. From the two buffer solutions tested, the results have shown better biogas production with NH4Cl- NH4OH than NH4Cl- NH4OH- H6NO4P . The first one have produced 50 % more biogas in comparison with the second buffer tested.Tema 6: Energía eólica, geotermia, biomasa y otras energías no convencionales.Facultad de Arquitectura y Urbanism

    Producción de biogás: incidencia del ph inicial en procesos de digestión anaeróbica

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    En este trabajo se ensayaron distintas soluciones buffer para optimizar la producción de biogás en codigestión anaeróbica de residuos de cebolla y estiércol vacuno. Se realizaron mediciones de pH, volumen generado de biogás, Ácidos Grasos Volátiles (AVG) y alcalinidad con el fin de correlacionar estos parámetros con la producción de biogás. De las distintas soluciones probadas, se presentan las que han mostrado mejores resultados en relación con la generación de biogás. La solución buffer NH4Cl- NH4OH produce un 50 % más de biogás que con la que contiene P (H6NO4P) , lo que se refleja en la evolución del pH, y los AVG, ya que en el reactor con baja producción de biogás el pH baja a valores indeseables hasta la acidificación del mismo (5,76), y se produce una acumulación de AVG hasta 5.100 mg/L.Batch experiments were carried out to test some buffer solutions in order to optimize biogas production by anaerobic codigestion of onion wastes and cow manure. The results of batch experiments showed pH, VFA (volatile fatty acids), and alkalinity trends, regarding biogas production. From the two buffer solutions tested, the results have shown better biogas production with NH4Cl- NH4OH than NH4Cl- NH4OH- H6NO4P . The first one have produced 50 % more biogas in comparison with the second buffer tested.Tema 6: Energía eólica, geotermia, biomasa y otras energías no convencionales.Facultad de Arquitectura y Urbanism

    First experimental evaluation of the alpha efficiency in coarse-grained quartz for ESR dating purposes: implications for dose rate evaluation

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    We present the first experimental evaluation of the alpha efficiency value for electron spin resonance (ESR) dating of coarse quartz grains, which is used for the evaluation of the internal and external alpha dose rate components. Based on our results, we recommend the use of an a-value of 0.07 ± 0.01 (1σ) for both the Al and Ti centres. Although we acknowledge that quartz ESR alpha efficiency may be sample dependent, and could also be impacted by other sources of uncertainty, this potential variability is presently impossible to evaluate given the absence of other experimental a-values available in the ESR dating literature. Measured radioactivity of quartz grains from the Moulouya catchment (NE Morocco) provides an internal dose rate in the range of 50–70 µGy/a when using an a-value of 0.07. The use of this empirically derived a-value for the evaluation of the internal and external alpha dose rate has a limited overall impact on the final ESR age results: they change by <2% and <3%, respectively, in comparison with those obtained with an assumed a-value. However, the large variability observed among the broader sample dataset for quartz internal radioactivity and hydrofluoric acid (HF) etching rates underscores the potential importance of undertaking experimental evaluations of alpha dose rate parameters for each dated sample.Melanie Bartz, Lee J. Arnold, Nigel A. Spooner, Martina Demuro, Isidoro Campaña, Gilles Rixhon, Helmut Brückner, Mathieu Duva

    Soil: the great connector of our lives now and beyond COVID-19

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    Humanity depends on the existence of healthy soils, both for the production of food and for ensuring a healthy, biodiverse environment, among other functions. COVID-19 is threatening food availability in many places of the world due to the disruption of food chains, lack of workforce, closed borders and national lockdowns. As a consequence, more emphasis is being placed on local food production, which may lead to more intensive cultivation of vulnerable areas and to soil degradation. In order to increase the resilience of populations facing this pandemic and future global crises, transitioning to a paradigm that relies more heavily on local food production on soils that are carefully tended and protected through sustainable management is necessary. To reach this goal, the Intergovernmental Technical Panel on Soils (ITPS) of the Food and Agriculture Organization of the United Nations (FAO) recommends five active strategies: improved access to land, sound land use planning, sustainable soil management, enhanced research, and investments in education and extension

    Safety and immunomodulatory effects of three probiotic strains isolated from the feces of breast-fed infants in healthy adults: SETOPROB study

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    We previously described the isolation and characterization of three probiotic strains from the feces of exclusively breast-fed newborn infants: Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036. These strains were shown to adhere to intestinal mucus in vitro, to be sensitive to antibiotics and to resist biliary salts and low pH. In the present study, a multicenter, randomized, double-blind, placebo-controlled trial with 100 healthy volunteers in three Spanish cities was carried out to evaluate the tolerance, safety, gut colonization and immunomodulatory effects of these three probiotics. Volunteers underwent a 15-day washout period, after which they were randomly divided into 5 groups that received daily a placebo, a capsule containing one of the 3 strains or a capsule containing a mixture of two strains for 30 days. The intervention was followed by another 15-day washout period. Patients did not consume fermented milk for the entire duration of the study. Gastrointestinal symptoms, defecation frequency and stool consistency were not altered by probiotic intake. No relevant changes in blood and serum, as well as no adverse events occurred during or after treatment. Probiotic administration slightly modified bacterial populations in the volunteers’ feces. Intestinal persistence occurred in volunteers who received L. rhamnosus CNCM I-4036. Administration of B. breve CNCM I-4035 resulted in a significant increase in fecal secretory IgA content. IL-4 and IL-10 increased, whereas IL-12 decreased in the serum of volunteers treated with any of the three strains. These results demonstrate that the consumption of these three bacterial strains was safe and exerted varying degrees of immunomodulatory effects.Part of the research currently in progress in the authors' laboratory is funded by the company Hero Spain, S. A. through the grant #3582 managed by the Fundacion General Empresa-Universidad de Granada
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