182 research outputs found

    Behavior and Impact of Zirconium in the Soil–Plant System: Plant Uptake and Phytotoxicity

    Get PDF
    Because of the large number of sites they pollute, toxic metals that contaminate terrestrial ecosystems are increasingly of environmental and sanitary concern (Uzu et al. 2010, 2011; Shahid et al. 2011a, b, 2012a). Among such metals is zirconium (Zr), which has the atomic number 40 and is a transition metal that resembles titanium in physical and chemical properties (Zaccone et al. 2008). Zr is widely used in many chemical industry processes and in nuclear reactors (Sandoval et al. 2011; Kamal et al. 2011), owing to its useful properties like hardness, corrosion-resistance and permeable to neutrons (Mushtaq 2012). Hence, the recent increased use of Zr by industry, and the occurrence of the Chernobyl and Fukashima catastrophe have enhanced environmental levels in soil and waters (Yirchenko and Agapkina 1993; Mosulishvili et al. 1994 ; Kruglov et al. 1996)

    Etest® versus broth microdilution for ceftaroline MIC determination with Staphylococcus aureus: results from PREMIUM, a European multicentre study

    Get PDF
    Objectives: To compare the concordance of ceftaroline MIC values 24 by reference broth microdilution (BMD) and Etest (BioMérieux, France) for MSSA and MRSA isolates, respectively, in isolates from PREMIUM (D372SL00001), a European multi-centre study.  Methods: Ceftaroline MICs were determined by reference BMD and by Etest for 1,242 MSSA and MRSA from adult patients with community-acquired pneumonia or complicated skin and soft tissue infections collected between February and May 2012; tests were performed across six European laboratories. Selected isolates with ceftaroline resistance in broth (MIC >1 mg/L) were retested in three central laboratories to confirm their behaviour.  Results: Overall concordance between BMD and Etest was good, with >97% essential agreement and >95% categorical agreement. Nevertheless, 12 of the 26 MRSA isolates found resistant by BMD scored as susceptible by Etest, with MICs ≤1 mg/L, thus counting as very major errors, whereas only five of 380 MRSA found ceftaroline susceptible in BMD were mis-categorised as resistant by Etest. Twenty-one of the 26 isolates with MICs of 2 mg/L by BMD were then re-tested twice by each of three central laboratories: BMD MICs of 2 mg/L were consistently found for 19 of the 21 isolates. Among 147 Etest results for these 21 isolates (original plus six repeats per isolate) 112 were >1 mg/L.  Conclusions: BMD and Etest have good overall agreement for ceftaroline against Staphylococcus aureus; nevertheless, reliable Etest-based discrimination of the minority of ceftaroline-resistant (MIC 2 mg/L) MRSA is extremely challenging, requiring careful reading of strips, ideally with duplicate testing

    The spatial distribution of aeolian dust and terrigenous fluxes in the tropical Atlantic Ocean since the Last Glacial Maximum

    Get PDF
    © 2021. American Geophysical Union. All Rights Reserved. The flux of terrestrial material from the continents to the oceans links the lithosphere, hydrosphere, and biosphere through physical and biogeochemical processes, with important implications for Earth's climate. Quantitative estimates of terrigenous fluxes from sources such as rivers, aeolian dust, and resuspended shelf sediments are required to understand how the processes delivering terrigenous material respond to and are influenced by climate. We compile thorium-230 normalized 232Th flux records in the tropical Atlantic to provide an improved understanding of aeolian fluxes since the Last Glacial Maximum (LGM). By identifying and isolating sites dominated by aeolian terrigenous inputs, we show that there was a persistent meridional gradient in dust fluxes in the eastern equatorial Atlantic at the LGM, arguing against a large southward shift of the intertropical convergence zone during LGM boreal winter. The ratio of LGM to late-Holocene 232Th fluxes highlights a meridional difference in the magnitude of variations in dust deposition, with sites 700 km away, characterized by 232Th fluxes approximately twice as large as aeolian-dominated sites in the east

    Production, Transmission, Pathogenesis, and Control of Dengue Virus: A Literature-Based Undivided Perspective

    Get PDF
    Dengue remains one of the most serious and widespread mosquito-borne viral infections in human beings, with serious health problems or even death. About 50 to 100 million people are newly infected annually, with almost 2.5 billion people living at risk and resulting in 20,000 deaths. Dengue virus infection is especially transmitted through bites of Aedes mosquitos, hugely spread in tropical and subtropical environments, mostly found in urban and semiurban areas. Unfortunately, there is no particular therapeutic approach, but prevention, adequate consciousness, detection at earlier stage of viral infection, and appropriate medical care can lower the fatality rates. This review offers a comprehensive view of production, transmission, pathogenesis, and control measures of the dengue virus and its vectors.This work was supported by CONICYT PIA/APOYO CCTE AFB170007

    Spontaneous haemorrhage of an adrenal angiomyolipoma: case report

    Get PDF
    Background Angiomyolipomas are rare mesenchymal tumours arising from the perivascular epithelioid cells consisting of variable amounts of adipose, thick-walled blood vessels and smooth muscle cells. These benign tumours commonly occur in the kidney with only a few case reports of adrenal angiomyolipomas which have the potential to reach a large size and haemorrhage. Case presentation A 45-year-old lady presented with a 3-week history of right loin pain, nausea and vomiting. A CT scan revealed a right adrenal angiomyolipoma measuring 6.3 × 6.8 cm with associated haemorrhage. The lesion was successfully treated with right open adrenalectomy, and histology confirmed the diagnosis of adrenal angiomyolipoma. The patient remained well with no evidence of recurrence at the 36-month follow-up. Conclusion Adrenal angiomyolipomas are rare benign tumours that have the ability to reach a large size and potential to bleed. Here, we report the second case of spontaneous haemorrhage in an adrenal angiomyolipoma, which was successfully treated with open adrenalectomy

    The Gaia-ESO Survey: Calibrating the lithium-age relation with open clusters and associations. II. Expanded cluster sample and final membership selection

    Full text link
    The Li abundance observed in pre-main sequence and main sequence late-type stars is strongly age-dependent, but also shows a complex pattern depending on several parameters, such as rotation, chromospheric activity and metallicity. The best way to calibrate these effects, with the aim of studying Li as an age indicator for FGK stars, is to calibrate coeval groups of stars, such as open clusters (OCs) and associations. We present a considerable target sample of 42 OCs and associations, ranging from 1 Myr to 5 Gyr, observed within the Gaia-ESO survey (GES), and using the latest data provided by GES iDR6 and the most recent release of Gaia that was then available, EDR3. As part of this study, we update and improve the membership analysis for all 20 OCs presented in our previous article. We perform detailed membership analyses for all target clusters to identify likely candidates, using all available parameters provided by GES and based on numerous criteria: from radial velocity distributions, to the astrometry and photometry provided by Gaia, to gravity indicators, [Fe/H] metallicity, and Li content. We obtain updated lists of cluster members for the whole target sample, as well as a selection of Li-rich giant contaminants obtained as an additional result of the membership process. Each selection of cluster candidates was thoroughly contrasted with numerous existing membership studies using data from Gaia to ensure the most robust results. These final cluster selections will be used in the third and last paper of this series, which reports the results of a comparative study characterising the observable Li dispersion in each cluster and analysing its dependence on several parameters, allowing us to calibrate a Li-age relation and obtain a series of empirical Li envelopes for key ages in our sample.Comment: 83 pages, 246 figures. To be published in A&A, accepted January 27, 202

    Guidelines for identification and treatment of individuals with attention deficit/hyperactivity disorder and associated fetal alcohol spectrum disorders based upon expert consensus

    Get PDF
    Background: The association of attention deficit/hyperactivity disorder (ADHD) and fetal alcohol spectrum disorders (FASD) results in a complex constellation of symptoms that complicates the successful diagnosis and treatment of the affected individual. Current literature lacks formal guidelines, randomized control trials, and evidence-based treatment plans for individuals with ADHD and associated FASD. Therefore, a meeting of professional experts was organized with the aim of producing a consensus on identification and treatment guidelines that will aid clinicians in caring for this unique patient population. Methods: Experts from multiple disciplines in the fields of ADHD and FASD convened in London, United Kingdom, for a meeting hosted by the United Kingdom ADHD Partnership (UKAP; www.UKADHD.com) in June 2015. The meeting provided the opportunity to address the complexities of ADHD and FASD from different perspectives and included presentations, discussions, and group work. The attendees worked towards producing a consensus for a unified approach to ADHD and associated FASD. Results: The authors successfully came to consensus and produced recommended guidelines with specific regards to identification and assessment, interventions and treatments, and multiagency liaisons and care management, highlighting that a lifespan approach to treatment needs to be adopted by all involved. Included in the guidelines are: 1) unique 'red flags', which when identified in the ADHD population can lead to an accurate associated FASD diagnosis, 2) a treatment decision tree, and 3) recommendations for multiagency care management. Conclusions: While clinically useful guidelines were achieved, more research is still needed to contribute to the knowledge base about the diagnosis, treatment, and management of those with ADHD and associated FASD

    Broadband Coupling into a Single-Mode, Electroactive Integrated Optical Waveguide for Spectroelectrochemical Analysis of Surface-Confined Redox Couples

    Get PDF
    Pushing the sensitivity of spectroelectrochemical techniques to routinely monitor changes in spectral properties of thin molecular films (i.e., monolayer or submonolayer) adsorbed on an electrode surface has been a goal of many investigators since the earliest developments in this field. 1 It was initially recognized that exploiting the evanescent field generated by total internal reflection at the interface of an optically transparent electrode (such as a thin film of tin oxide or indium tin oxide (ITO) on glass or quartz) has the inherent advantage of selectively probing only the near-surface region, as opposed to bulk sampling with transmission based techniques. Furthermore, by utilizing the multiple reflections in an attenuated total reflectance (ATR) geometry, an enhancement in sensitivity can be realized, and as the thickness of the ATR element is decreased, the number of reflections increases, yielding a substantial sensitivity enhancement. [2][3][4][5][6] Itoh and Fujishima were the first to show the advantages of reducing the thickness of an ATR element overcoated with a transparent conductive oxide to the integrated optical waveguide (IOW) regime. Using a four-mode, gradient index waveguide coated with a transparent, conductive tin oxide layer, they demonstrated large sensitivity enhancements, relative to a single pass transmission experiment, for spectroelectrochemical measurements of methylene blue. 7,8 Other research groups subsequently described similar gradient index, multilayer, electroactive waveguide structures, but they did not make use of the technology to explore the spectroelectrochemistry of (sub)monolayer coverage films. [9][10][11][12][13] We recently described a single-mode, electroactive planar IOW (the EA-IOW) having a step refractive index profile. It was fabricated by sputtering a Corning 7059 glass layer (400 nm) over soda lime glass or quartz, followed by a 200-nm layer of SiO 2
    corecore