166 research outputs found

    Continuous stellate ganglion block in delayed cerebral ischemia: A possible supplementary approach to traditional therapy?

    Get PDF
    Delayed Cerebral Ischemia (DCI) is a major contributor to morbidity and mortality after SAH. Currently the prevention of vasospasm and DCI relies on nimodipine administration and on maintaining an adequate cerebral perfusion pressure. We report a patient with initial DCI after SAH in which stellate ganglion block (SGB) was performed after nimodipine administration. Firstly the procedure was characterized by a iv and intra-arterial nimodipine administration which did not result into a normal perfusion pattern. Therefore a single-shot stellate ganglion block was performed, as suggested in literature. Because of the not sufficient but promising perfusion improvement, we decided to deliver a continuous ganglion block (cSGB) for 5 days. Consequently a further improvement of the cerebral perfusion on CTPerfusion and Real Time Angiographic Perfusion Assessment was registered. In order to treat cerebral vasospasm, SGB is known to be a further valuable treatment, despite its temporary effect. However the continuous use of SGB during initial DCI has never been described before

    CO2-assisted hydrolytic hydrogenation of cellulose and cellulose-based waste into sorbitol over commercial Ru/C

    Get PDF
    A single-step protocol was developed for the hydrolytic hydrogenation of microcrystalline cellulose into sorbitol over commercial carbon-supported Ru, in the presence of gaseous CO2 as an acid source and molecular hydrogen as a reductant. Under these conditions, cellulose was first hydrolysed to glucose by reversibly formed carbonic acid in water and then instantaneously hydrogenated on Ru/C. By tuning the reaction parameters, such as temperature, time and the relative pressure of CO2 and hydrogen gas, cellulose was fully converted at 220 & DEG;C in 18 h under 30 and 40 bar of H-2 and CO2, respectively, with a sorbitol yield of 81%. Blank experiments revealed that without a catalyst and hydrogen, the reaction exhibited <5% conversion and glucose was the only detected product when the reaction was performed under CO2 pressure. XRD measurements on CO2-treated cellulose surprisingly revealed no noticeable changes in the crystallinity index (<10% with respect to microcrystalline cellulose), suggesting that hydrolytic hydrogenation took place on crystalline, not amorphous, cellulose. Furthermore, not only several cellulosic feedstocks, including filter paper, cotton wool, and cotton fiber, but also typical cellulose-based wastes such as a cardboard pizza box were also tested and under the optimized conditions sorbitol was obtained with yields ranging from 56% up to 72% in all cases. No less significant was the Ru/C catalyst stability, which could be recycled at least six times without any noticeable activity loss

    A year-round measurement of water-soluble trace and rare earth elements in arctic aerosol: Possible inorganic tracers of specific events

    Get PDF
    This study presents the year-round variability of the water-soluble fraction of trace elements (wsTE) and rare earth elements (wsREE) among size segregated airborne particulate matter samples collected at Ny-Ã… lesund in the Svalbard Archipelago from 26 February 2018 to 26 February 2019. Six different aerosol dimensional fractions were collected using a multi-stage Andersen impactor to better understand local and global circulation with the aim of disentangling the source of inorganic tracers from specific natural or anthropogenic sources. The wsTE and wsREE content, especially in the finest fractions in remote areas, is primarily related to long-range transport and it gives valuable information on (1) the global circulation, (2) the natural sources and (3) the contribution of human activities to aerosol composition. A Factor Analysis was applied to the dataset, including levoglucosan and methanesulfonic acid (MSA), to assess the possibility of using certain inorganic tracers as indicators of specific transport events or circulation regimes. We also investigate back-trajectories to determine potential source areas

    The Occurrence of Glyphosate and its Degradation Products in the Urban Stormwater: A Short Review

    Get PDF
    Due to urbanization and industrialization, water pollution is now one of the major environmental challenges of the twenty-first century. Considering the increasing of agricultural and non-agricultural settings in the last decades, the investigation of the relationship between such pesticides and urban stormwater is critical to understand how urban, residential, and industrialized areas can affect environmental safety. Recently, scientific interest has grown in stormwater chemical characterization with the aim to define its impacts in the environment and possibly to make it potable water. In this context, glyphosate, glufosinate, and their degradation products have been identified as the key knowledge gap for the chemical characterization of stormwater. Research investments are needed for a better understanding of the highly polar pesticides to estimate their load, source, and dispersion of urban runoff due to residential use of herbicides. Furthermore, a more comprehensive study of wet and dry deposition and spray drift should be considered for a correct evaluation of source apportionment

    Occurrence and phase distribution of benzothiazoles in untreated highway stormwater runoff and road dust

    Get PDF
    The study about how tyre-derived particles can potentially worsen the water quality and how traffic pollution markers can affect the environment is crucial for environmental management. Road emissions are known to contribute to pollution in various environments, and benzothiazoles and their derivates can be used to trace pollutant inputs related to surface runoff in the aquatic system. A total of eight benzothiazoles were determined in highway stormwater runoff and road dust collected from February to August 2022 near Venice (Casale sul Sile, Veneto Region, Italy). A new analytical method was validated, by using an UHPLC system coupled to a mass spectrometer (triple quadrupole). The target compounds were determined in both dissolved phase and suspended particulate matter of runoff, and the road dust samples were divided into seven fractions depending on particle diameters to understand the fraction partitioning. The results indicate that 2-SO3H-BTH was the most concentrated benzothiazole in all the analysed substrates, suggesting tyre debris as the main source because it is usually used in the vulcanization process. 2-SO3H-BTH reached a mean concentration of 115 +/- 59 mu g L-1, 4 +/- 3 mu g L-1, and 411 +/- 441 mu g Kg(-1) for dissolved phase, suspended particulate matter, and road dust, respectively, while 2-OH-BTH and BTH showed values about an order of magnitude lower. The size distribution of most BTHs suggests that they are distributed in the finest fraction of road dust. An exception was given by 2-SCNMeS-BTH being present only in particles with a diameter > 1 mm

    The disinfection by-products are in the air: Aerosol measurements in the urban area of Venice

    Get PDF
    Haloacetic acids (HAAs) are usually taken to be man-made, regularly determined in drinking water as disinfection by-products; yet they have been demonstrated as a probable photooxidation products from atmospheric halogenated hydrocarbons. Here we determined a total of fourteen HAAs, including for the first time iodinatedHAAs, in aerosol samples collected from April to June 2023 at Parco Bissuola (urbanized area of Venice) and Rio Novo (Venice island). The study provides a first insight and source identification about the anthropogenic or natural origin of HAAs. To fulfil this aim, we improved existing methods with a highly sensitive technique by using high pressure anion exchange chromatography coupled to a triple quadrupole mass spectrometer. Five HAAs have been found to be above the detection limits at both sites, and the major source should be attributed to a mixed contribution from atmospheric oxidation of both organic precursor, sea spray and a minor contribution of an external swimming pool located near the Parco Bissuola site. Considering the presence of iodinated HAAs and their cytotoxicity, the present study also provides a basis for the assessment of risks for humans

    Amino acid modified graphene oxide for the simultaneous capture and electrochemical detection of glyphosate

    Get PDF
    Amino acid modified graphene oxide derivatives (GO-AA) are herein proposed as active materials for the capture and consequent electrochemical detection of organic pollutants in aqueous media. Glyphosate (GLY), an herbicide present in many water compartments, was chosen as benchmark species to test the effectiveness of these materials for its electroactive nature, allowing direct evidence of the capture event. L-Lysine, L-Arginine or LMethionine were grafted on GO surface through epoxide ring opening reaction, promoting the amino acids binding and the concomitant partial reduction of GO. The synthetic process results in a charge resistance drop from 8.1 KΩ for GO to 0.8–2.1 KΩ for the various GO-AA, supporting the applicability of these materials in electrochemical sensing. The resulting GO-Lysine, GO-Arginine and GO-Methionine were exploited for GLY adsorption from water. GO-Lysine was found to have the strongest interaction with GLY, with a removal efficiency of 76 % after 1 h, which is about two-fold higher than those of granular activated carbon, the industrial benchmark adsorbent. GO-AAs outperform the pristine unmodified material also when exploited as active materials for the capturing and following electrochemical detection of GLY. GO-Lysine showed the best sensitivity and allowed the recognition of GLY in water even when present at concentration levels down to 2 μg/L. Molecular dynamics simulations confirmed that the enhanced performance of this material can be ascribed to the hydrogen bond and salt bridge interactions between Lys moieties and GLY, originated from hydrogen bond and salt bridge interactions

    SARS-CoV-2 concentrations and virus-laden aerosol size distributions in outdoor air in north and south of Italy

    Get PDF
    The COVID-19 disease spread at different rates in the different countries and in different regions of the same country, as happened in Italy. Transmission by contact or at close range due to large respiratory droplets is widely accepted, however, the role of airborne transmission due to small respiratory droplets emitted by infected individuals (also asymptomatic) is controversial. It was suggested that outdoor airborne transmission could play a role in determining the differences observed in the spread rate. Concentrations of virus-laden aerosol are still poorly known and contrasting results are reported, especially for outdoor environments. Here we investigated outdoor concentrations and size distributions of virus-laden aerosol simultaneously collected during the pandemic, in May 2020, in northern (Veneto) and southern (Apulia) regions of Italy. The two regions exhibited significantly different prevalence of COVID-19. Genetic material of SARS-CoV-2 (RNA) was determined, using both real time RT-PCR and ddPCR, in air samples collected using PM10 samplers and cascade impactors able to separate 12 size ranges from nanoparticles (diameter D < 0.056 µm) up to coarse particles (D > 18 µm). Air samples tested negative for the presence of SARS-CoV-2 at both sites, viral particles concentrations were <0.8 copies m−3 in PM10 and <0.4 copies m−3 in each size range investigated. Outdoor air in residential and urban areas was generally not infectious and safe for the public in both northern and southern Italy, with the possible exclusion of very crowded sites. Therefore, it is likely that outdoor airborne transmission does not explain the difference in the spread of COVID-19 observed in the two Italian regions

    Fast Liquid Chromatography Coupled with Tandem Mass Spectrometry for the Analysis of Vanillic and Syringic Acids in Ice Cores

    Get PDF
    The development of new analytical systems and the improvement of the existing ones to obtain high-resolution measurements of chemical markers in samples from ice cores, is one of the main challenges the paleoclimatic scientific community is facing. Different chemical species can be used as markers for tracking emission sources or specific environmental processes. Although some markers, such as methane sulfonic acid (a proxy of marine productivity), are commonly used, there is a lack of data on other organic tracers in ice cores, making their continuous analysis analytically challenging. Here, we present an innovative combination of fast liquid chromatography coupled with tandem mass spectrometry (FLC-MS/MS) to continuously determine organic markers in ice cores. After specific optimization, this approach was applied to the quantification of vanillic and syringic acids, two specific markers for biomass burning. Using the validated method, detection limits of 3.6 and 4.6 pg mL-1for vanillic and syringic acids, respectively, were achieved. Thanks to the coupling of FLC-MS/MS with the continuous flow analytical system, we obtained one measurement every 30 s, which corresponds to a sampling resolution of a sample every 1.5 cm with a melting rate of 3.0 cm min-1. To check the robustness of the method, we analyzed two parallel sticks of an alpine ice core over more than 5 h. Vanillic acid was found with concentrations in the range of picograms per milliliter, suggesting the combustion of coniferous trees, which are found throughout the Italian Alps
    • …
    corecore