167 research outputs found

    Visible light harvesting alkyne hydrosilylation mediated by pincer platinum complexe

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    In this manuscript we assess the catalytic properties of pincer platinum complexes in alkyne hydrosilylation either under photo or thermal conditions. The visible light-induced hydrosilylation proved to be more efficient. It can be performed at room temperature and required lower catalyst loadings than that operating under thermal conditions. The platinum complexes play a dual role in photohydrosilylation as serve as a photosensitizer and a catalyst enabling species in bond breaking/forming transformations. In addition, alkyne hydrosilylation is achieved with moderate regio- and stereoselectivity but is enhanced under photocatalytic conditions and in the case of terminal alkynes we have observed the formation of β(Z) products not observable under thermal conditions. Such differences in selectivity constitute an example of stereodivergent catalysis dictated under photochemical or thermal conditions. The selectivity differences are ascribed to a distinctive reaction mechanism for the light- vs thermally-induced process that involve radical or organometallic intermediates, respectively.MICIU/AEI/FEDER (PID2021-126071OB-C22 and PID2019-104121GB-I00). Universitat Jaume I (UJI-B2022-23). Generalitat Valenciana (PROMETEU/2020/028).Thanks to PID2021-126071OB-C22 and PID2019-104121GB-I00 funded by MICIN/AEI/10.13039/501100011033/ FEDER “Una manera de hacer Europa”. Generalitat Valenciana (PROMETEU/2020/028) and Universitat Jaume I (UJI-B2022-23). L. I-I. thanks MICIN for grant (FPU20/04385). The authors thank ‘Servei Central d’Instrumentació Científica (SCIC) de la Universitat Jaume I’

    Recent freshening and cooling of Biscay subsurface waters

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    The monitoring program Radiales (https://www.seriestemporales-ieo.net/) by the Spanish Institute of Oceanography, has been providing hydrographical and biogeochemical series in marine waters around Spain on a monthly basis from early 90's. The proximity of the shelf-break in front of the city of Santander (SE Bay of Biscay) allowed tracking intermediate and deep waters along the standard section perpendicular to this city for three decades (sampling was limited to 1000 meter until late 2007, then extended to 1500 m, and full-depth 2400 m since 2014). From the start of the sampling in nearly 90`s, subsurface waters showed unabated warming and salt-increase. Warming was linked to isopycnal sinking (heave) during the 90`s and early 00`s until the occurrence of very strong winter mixing in 2005 that shifted quickly the salinity down to lower East North Atlantic Central Waters (ENACW) levels (ca. 400 m). Overall, warming and salt-increase at the core of ENACW added up to 0.3ºC and 0.08 in salinity within only two and a bit decades. In 2014, the upper central waters showed freshening and cooling for the first time in the series, a process that enhanced in the following years especially in salinity that currently (2021) presents the lowest value of the overall timeseries. This shift in regional hydrography follows the large salinity drop observed in the subpolar gyre around 2012 and its subsequent expansion downstream into the subtropical gyre and subarctic seas. This regime shift implies that subsurface environmental conditions in the region have returned back to 90`s state, contrasting to the uppermost waters which continue to show large positive anomalies. The effects of this cold and freshwater inflow in the regional circulation of southern Biscay are discussed

    Sonochemical degradation of antibiotics from representative classes-Considerations on structural effects, initial transformation products, antimicrobial activity and matrix

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    In this work, the sonochemical treatment (at 354 kHz and 88 W L-120 ) of six relevant antibiotics belonging to fluoroquinolones (ciprofloxacin and norfloxacin), penicillins (oxacillin and cloxacillin) and cephalosporins (cephalexin and cephadroxyl) classes was evaluated. Firstly, the ability of the process to eliminate them was tested, showing that sonodegradation of these antibiotics is strongly chemical structure25 dependent. Thus, correlations among initial degradation rate of pollutants (Rd), solubility in water (Sw), water-octanol partition coefficient (Log P) and topological polar surface area (TPSA) were tested. Rd exhibited a good correlation with Log P (i.e., the hydrophobicity degree of antibiotics). The considered penicillins had the fastest elimination and from the constitutional analysis using Lemke method was clear that the functional groups arrangement on these antibiotics made them highly hydrophobics. The penicillins were degraded closer at cavitation bubble than the fluoroquinolones or cephalosporins. The investigation of degradation products showed that sonogenerated hydroxyl radical primary attacked the β-lactam ring of cloxacillin and cephalexin, whereas on norfloxacin induced a decarboxylation. On the other hand, the evolution of antimicrobial activity was also followed. It was evidenced the process capacity to remove antimicrobial activity from treated solutions, which was associated to the transformations of functional groups on antibiotics with important role for interaction with bacteria. Additionally, degradation of antibiotics having the highest (the most hydrophobic, i.e., cloxacillin) and lowest (the most hydrophilic, i.e., cephadroxyl) Rd, was performed in synthetic matrices (hospital wastewater and seawater). Ultrasound degraded both antibiotics; for cloxacillin in such waters higher eliminations than in distilled water were observed (probably due to a salting-out effect exerted by matrix components). Meanwhile, for cephadroxyl a moderate inhibition of degradation in hospital wastewater and seawater respect to distilled water was found, this was related to competition by hydroxyl radical of the other substances in the matrices. These results show the quite selectivity of high frequency ultrasound to eliminate antibiotics form different classes even in complex matrices

    iFADO project: contribution to the determination of the Good Environmental Status in the Atlantic Area through modeling and in situ monitoring approaches

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    The project iFADO ( innovation in the Framework of the Atlantic Deep Ocean ) aims to combine conventional monitoring programs (with special focus on novel semi-automatic techniques that can be applied for in situ biological monitoring) with emerging technologies (such as gliders, satellite imagery, etc.) and modeling approaches to assist the implementation of the Marine Strategy Framework Directive (MSFD), providing tools for the optimization of observing strategies for better evaluation and forecasting of the Good Environmental Status (GES). Within this framework, the multidisciplinary iFADO cruise (within the RADPROF time series program, Instituto Español de Oceanografía) was carried out with transnational collaboration on summer 2020 along a standard coastal-oceanic transect off NW Iberian Peninsula, including physical, biogeochemical and biological measurements. Additionally, an effort is being made in the implementation and validation of existing and new biogeochemical models in the Atlantic margin, focusing on key variables for the implementation of MSFD Descriptors. The combination of iFADO models and in situ monitoring approaches not only might contribute data and potential indicators for MSFD Descriptors 1, 2, 3, 4, 5, 6, 7 and 10, from coastal to open-ocean environments, but they are essential tools to detect, model and predict temporal changes in marine ecosystems in the study area

    Estimation of water erosion in the Necaxa system, Puebla, Mexico

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    Objective: Estimate potential and current water erosion in the Necaxa System and propose alternatives to reduce the problem of siltation of the hydraulic infrastructure Design/methodology/approach: The Universal Soil Loss equation will be applied through algebra of maps processed in a Geographic Information System. Results: It was estimated that the current water erosion in the Necaxa system is 159 tons / ha * year, a factor that affects the loss of land for crops, loss of nutrients in the soil, accumulation of material towards urban areas, silting up of streams, reservoirs and loss of capacity of the hydraulic works of the system. Limitations on study/implications: There is no information on runoff batches in the field that allows the current water erosion values to be compared with those obtained by the EUPS applied by map algebra. Findings/conclusions: By proposing reforestation and carrying out conservation agriculture, it could be reduced to 16 tons / ha * year. However, if control actions are not carried out and the current coverage is not preserved, the problem can increase until reaching potential erosion values higher than 200 ton / ha * year.Objective: To estimate the potential and current water erosion in the Necaxa system and to propose alternatives aimed to reduce the siltation problem in the hydraulic infrastructure.Design/methodology/approach: The Universal Soil Loss Equation (USLE) was applied, using a Geographic Information System to process the map algebra.Results: The current estimated water erosion was 159 t ha-1 per year; this factor impacts the loss of farmland and soil nutrients, the accumulation of matter towards urban areas, the siltation of riverbeds and dams, and the loss of the system’s hydraulic works capacity.Study limitations/implications: No data about runoff plots in the field is available; therefore, it is not possible to compare current water erosion values with those obtained by the USLE applied, using the map algebra technique. Findings/conclusions: The reforestation and conservation agriculture proposal would help to reduce erosion to 16 t ha -1 per year. However, if control actions are not carried out and the current vegetation cover is not preserved, the problem can increase until it reaches potential erosion values >200 t ha -1 per year

    Análisis de sequías meteorológicas en la cuenca del río Fuerte, México

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    Castillo-Castillo, M., Ibáñez-Castillo, L. A., Valdés, J. B., Arteaga-Ramírez, R., & Vázquez-Peña, M. A. (enero-febrero, 2017). Análisis de sequías meteorológicas en la cuenca del río Fuerte, México. Tecnología y Ciencias del Agua, 8(1), 35-52. En este trabajo se realiza un análisis temporal y espacial de la sequía en la cuenca del río Fuerte para el periodo de 1961 a 2012. La cuenca del río Fuerte se ubica al noroeste de México, en la zona de baja presión, donde coinciden en latitud los grandes desiertos del mundo; en la parte alta de la cuenca viven diversos grupos indígenas en condiciones de pobreza y en la parte baja se ubica una zona agrícola bajo riego muy importante. Se calcularon dos índices de sequía: (1) el Índice Estandarizado de Precipitación (SPI) y (2) el Índice Estandarizado de Precipitación-Evapotranspiración (SPEI); ambos índices fueron calculados en 14 estaciones del área de estudio para escalas de 3, 6, 12 y 24 meses. Se utilizaron datos de precipitación, y temperatura mínima y máxima para el cálculo. Los índices fueron calculados y analizados temporal y espacialmente. Los resultados mostraron que las sequías han alterado su patrón de ocurrencia y se presentan con mayor frecuencia, intensidad y duración en las últimas décadas. Se encontraron dos periodos de sequías extremas: de 1999 a 2004 y de 2011 en adelante. El SPEI define mejor los periodos secos y presenta un comportamiento más estable que el SPI, además muestra una tendencia más clara del aumento en la intensidad de la sequía en los últimos años, producto de la reducción de la precipitación y el aumento de las temperaturas

    The influence of CYP enzymes and ABCB1 on treatment outcomes in schizophrenia: association of CYP1A2 activity with adverse effects

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    Aim: Genetic variants on metabolic and transport enzymes are good candidates to explain inter-individual differences in response to antipsychotics. The aim of this study is to evaluate and compare the influence of the CYP2D6, CYPC19, CYP1A2 and ABCB1 variants on plasma levels, treatment response and side effects of antipsychotics. Methods: Twenty polymorphisms in selected genes were genotyped in 318 patients diagnosed with schizophrenia, schizoaffective or delusional disorder treated with antipsychotics (clozapine, olanzapine, paliperidone, risperidone, aripiprazole and quetiapine). Plasma drug levels were determined after 6 weeks of treatment. The Positive and Negative Symptoms Scale (PANSS) and UKU scale of side effects were recorded at baseline and after 12 weeks of treatment. The effect of gene variants on plasma drug levels, treatment response and adverse effects were examined by multinomial regression. Results:CYP1A2 was found to be associated with psychic side effects (P = 0.02), with variants predicting higher enzyme activity associated with lower adverse effects, and was the strongest predictor for this adverse effect of all the studied factors. Functional variants in CYP genes were associated with plasma level differences, with higher activity variants associated with lower plasma levels. No association with improvement of the condition, as measured by the PANSS score, was found in this study. Conclusion: The results suggest that increased CYP1A2 activity protects against psychic side effects. Few studies have evaluated the impact of genetic factors on treatment response or side effects, and only in relation to a selection of adverse reactions. These results are a step towards better understanding of the factors behind the different aspects of clinical outcomes, such as various adverse effects

    Co-Mn Mineralisations in the Ni Laterite Deposits of Loma Caribe (Dominican Republic) and Loma de Hierro (Venezuela)

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    Cobalt demand is increasing due to its key role in the transition to clean energies. Although the main Co ores are the sediment-hosted stratiform copper deposits of the Democratic Republic of the Congo, Co is also a by-product of Ni-Co laterite deposits, where Co extraction efficiency depends, among other factors, on the correct identification of Co-bearing minerals. In this paper, we reported a detailed study of the Co mineralisation in the Ni-Co laterite profiles of Loma Caribe (Dominican Republic) and Loma de Hierro (Venezuela). Cobalt is mainly associated with Mn-oxyhydroxide minerals, with a composition between Ni asbolane and lithiophorite, although a Co association with phyllosilicates has also been recorded in a Loma de Hierro deposit. In Loma Caribe, Co-bearing Mn-oxyhydroxide minerals mainly developed colloform aggregates, and globular to spherulitic grains, while in Loma de Hierro, they displayed banded colloform, fibrous or tabular textures. Most of the compositional analyses of Mn-oxyhydroxides yielded 20 and 40 wt.% Mn, with Ni and Co up to 16 and 10 wt.%, respectively. In both profiles, Mn-bearing minerals were mainly found in the transition from the oxide horizon to the saprolite, as observed in other laterite profiles in the world, where the precipitation of Mn-bearing minerals is enhanced because of the pore solution saturation and pH increas

    Severe cardiac and abdominal manifestations without lung involvement in a child With COVID-19

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    Coronavirus disease 2019 (COVID-19) has become a worldwide pandemic, affecting humans of all ages. Clinical features of the pediatric population have been published, but there is not yet enough information to make a definitive description. Fever is typical, as it is respiratory symptom. Rarely are the infection and complications severe, and, when they are, it is almost always in a patient with another underlying disease. However, some otherwise healthy children with COVID-19 do suffer critical organ injury, such as acute myocarditis, heart failure and gastrointestinal inflammation. The mechanism of these organ damages remains unclear. An otherwise normally healthy 13-year-old male was admitted to the pediatric intensive care unit with acute abdomen pain, possible myocarditis and a suspected diagnosis of COVID-19. Noteworthy basal findings were ventricular extrasystoles in the electrocardiogram (EKG) and moderate left ventricular systolic dysfunction. Chest X-ray was normal. Blood tests revealed altered levels of inflammation factors (C-reactive protein (CRP), D-dimer, fibrinogen, interleukin 6 (IL-6)), lymphopenia and elevated cardiac enzymes. The first test for polymerase chain reaction (PCR) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was negative. The patient’s condition worsened, and he entered cardiogenic shock (hypotension, tachycardia and oliguria). He was vomiting continuously, which made pain control difficult; imaging of his abdomen was undertaken. There was no response to fluid resuscitation, and so milrinone and epinephrine were administered. Empiric treatment began with azithromycin, foscarnet, carnitine and immunoglobulins. Hydroxychloroquine was given before the results of repeated SARSCoV-2 and serology tests were available. Tocilizumab was administered once COVID-19 had been confirmed and massive inflammation had been observed. Progressively the clinical situation and the levels of the parameters studied improved. The patient was discharged 8 days after admission. Most children with SARS-CoV-2 infection are asymptomatic or present only mild symptoms. However, physicians should be aware of atypical and severe manifestations that may occur in the hyperinflammatory phase of the illness

    A Single-Run Next-Generation Sequencing (NGS) Assay for the Simultaneous Detection of Both Gene Mutations and Large Chromosomal Abnormalities in Patients with Myelodysplastic Syndromes (MDS) and Related Myeloid Neoplasms

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    Chromosomal abnormalities and somatic mutations are found in patients with myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) in around 50-80% of cases. The identification of these alterations is important for the accurate diagnosis and prognostic classification of these patients. Often, an apparently normal or failed karyotype might lead to an inadequate estimation of the prognostic risk, and several strategies should be combined to solve these cases. The aim of this study was to introduce a novel next-generation sequencing (NGS)-based strategy for the simultaneous detection of all the clinically relevant genetic alterations associated with these disorders. We validated this approach on a large cohort of patients by comparing our findings with those obtained with standard-of-care methods (i.e., karyotype and SNP-arrays). We show that our platform represents a significant improvement on current strategies in defining diagnosis and risk stratification of patients with MDS and myeloid-related disorders. Myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms are clonal disorders that share most of their cytogenetic and molecular alterations. Despite the increased knowledge of the prognostic importance of genetics in these malignancies, next-generation sequencing (NGS) has not been incorporated into clinical practice in a validated manner, and the conventional karyotype remains mandatory in the evaluation of suspected cases. However, non-informative cytogenetics might lead to an inadequate estimation of the prognostic risk. Here, we present a novel targeted NGS-based assay for the simultaneous detection of all the clinically relevant genetic alterations associated with these disorders. We validated this platform in a large cohort of patients by performing a one-to-one comparison with the lesions from karyotype and single-nucleotide polymorphism (SNP) arrays. Our strategy demonstrated an approximately 97% concordance with standard clinical assays, showing sensitivity at least equivalent to that of SNP arrays and higher than that of conventional cytogenetics. In addition, this NGS assay was able to identify both copy-neutral loss of heterozygosity events distributed genome-wide and copy number alterations, as well as somatic mutations within significant driver genes. In summary, we show a novel NGS platform that represents a significant improvement to current strategies in defining diagnosis and risk stratification of patients with MDS and myeloid-related disorder
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