960 research outputs found

    Highly Sensitive Detection of the Antibiotic Ciprofloxacin by Means of Fiber Enhanced Raman Spectroscopy

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    Sepsis and septic shock exhibit a rapid course and a high fatality rate. Antibiotic treatment is time-critical and precise knowledge of the antibiotic concentration during the patients’ treatment would allow individual dose adaption. Over- and underdosing will increase the antimicrobial efficacy and reduce toxicity. We demonstrated that fiber enhanced Raman spectroscopy (FERS) can be used to detect very low concentrations of ciprofloxacin in clinically relevant doses, down to 1.5 µM. Fiber enhancement was achieved in bandgap shifted photonic crystal fibers. The high linearity between the Raman signals and the drug concentrations allows a robust calibration for drug quantification. The needed sample volume was very low (0.58 µL) and an acquisition time of 30 s allowed the rapid monitoring of ciprofloxacin levels in a less invasive way than conventional techniques. These results demonstrate that FERS has a high potential for clinical in-situ monitoring of ciprofloxacin levels

    Fiber enhanced Raman spectroscopic analysis as a novel method for diagnosis and monitoring of diseases related to hyperbilirubinemia and hyperbiliverdinemia

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    Fiber enhanced resonance Raman spectroscopy (FERS) is introduced for chemically selective and ultrasensitive analysis of the biomolecules hematin, hemoglobin, biliverdin, and bilirubin. The abilities for analyzing whole intact, oxygenated erythrocytes are proven, demonstrating the potential for the diagnosis of red blood cell related diseases, such as different types of anemia and hemolytic disorders. The optical fiber enables an efficient light-guiding within a miniaturized sample volume of only a few micro-liters and provides a tremendously improved analytical sensitivity (LODs of 0.5 μM for bilirubin and 0.13 μM for biliverdin with proposed improvements down to the pico-molar range). FERS is a less invasive method than the standard ones and could be a new analytical method for monitoring neonatal jaundice, allowing a precise control of the unconjugated serum bilirubin levels, and therefore, providing a better prognosis for newborns. The potential for sensing very low concentrations of the bile pigments may also open up new opportunities for cancer research. The abilities of FERS as a diagnostic tool are explored for the elucidation of jaundice with different etiologies including the rare, not yet well understood diseases manifested in green jaundice. This is demonstrated by quantifying clinically relevant concentrations of bilirubin and biliverdin simultaneously in the micro-molar range: for the case of hyperbilirubinemia due to malignancy, infectious hepatitis, cirrhosis or stenosis of the common bile duct (1 μM biliverdin together with 50 μM bilirubin) and for hyperbiliverdinemia (25 μM biliverdin and 75 μM bilirubin). FERS has high potential as an ultrasensitive analytical technique for a wide range of biomolecules and in various life-science applications

    Economic Feasibility of Ethanol Production from Sweet Sorghum Juice in Texas

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    The economic feasibility of producing ethanol from sweet sorghum juice is projected using Monte Carlo simulation models to estimate the price ethanol plants will likely have to pay for sweet sorghum and the uncertain returns for ethanol plants. Ethanol plants in high yielding regions will likely generate returns on assets of 11%-12% and in low yield areas the returns on assets will be less than 10%.Sweet Sorghum, Ethanol, Monte Carlo Simulation, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Risk and Uncertainty, D20 G10 D81 C15,

    Effect of Exposure to Small Pharmaceutical Promotional Items on Treatment Preferences

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    Background: Policy discussions concerning pharmaceutical promotion often assume that small promotional items are unlikely to influence prescribing behavior. Our experiment measures whether exposure to these items results in more favorable attitudes toward marketed products and whether policies that restrict pharmaceutical marketing mitigate this effect. Methods: This is a randomized controlled experiment of 352 third- and fourth-year medical students at two US medical schools with differing policies toward pharmaceutical marketing. Participants assigned to treatment were exposed to small branded promotional items for Lipitor (atorvastatin) without knowledge that the exposure was part of the study. We measured differences in implicit (ie, unconscious) attitudes toward Lipitor and Zocor (simvastatin) in exposed and control groups with the Implicit Association Test (IAT). Self-reported attitudes were also measured, and a follow-up survey was administered measuring attitudes toward marketing. Results: Fourth-year students at the University of Miami Miller School of Medicine exposed to Lipitor promotional items had more favorable implicit attitudes about that brand-name drug compared to the control group (IAT effect: 0.66 vs 0.47; P = .05), while the effect was reversed at the University of Pennsylvania School of Medicine (IAT effect: 0.22 vs 0.52; P = .002) where restrictive policies are in place limiting pharmaceutical marketing (interaction effect: P = .003). No significant effect was observed among third-year students. On a “skepticism” scale, University of Miami students held more favorable attitudes toward pharmaceutical marketing compared to University of Pennsylvania students (0.55 vs 0.42; P Conclusions: Subtle exposure to small pharmaceutical promotional items influences implicit attitudes toward marketed products among medical students. We observed a reversal of this effect in the setting of restrictive policies and more negative school-level attitudes toward marketing

    Effects of the Neutron Spin-Orbit Density on Nuclear Charge Density in Relativistic Models

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    The neutron spin-orbit density contributes to the nuclear charge density as a relativistic effect. The contribution is enhanced by the effective mass stemming from the Lorentz-scalar potential in relativistic models. This enhancement explains well the difference between the cross sections of elastic electron scattering off 40^{40}Ca and 48^{48}Ca which was not reproduced in non-relativistic models. The spin-orbit density will be examined in more detail in electron scattering off unstable nuclei which would be available in the future.Comment: 4 pages with 3 eps figures, revte

    Novel Compound Heterozygous Mutations Expand the Recognized Phenotypes of \u3cem\u3eFARS2\u3c/em\u3e-linked Disease

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    Mutations in mitochondrial aminoacyl-tRNA synthetases are an increasingly recognized cause of human diseases, often arising in individuals with compound heterozygous mutations and presenting with system-specific phenotypes, frequently neurologic. FARS2 encodes mitochondrial phenylalanyl transfer ribonucleic acid (RNA) synthetase (mtPheRS), perturbations of which have been reported in 6 cases of an infantile, lethal disease with refractory epilepsy and progressive myoclonus. Here the authors report the case of juvenile onset refractory epilepsy and progressive myoclonus with compound heterozygous FARS2 mutations. The authors describe the clinical course over 6 years of care at their institution and diagnostic studies including electroencephalogram (EEG), brain magnetic resonance imaging (MRI), serum and cerebrospinal fluid analyses, skeletal muscle biopsy histology, and autopsy gross and histologic findings, which include features shared with Alpers-Huttenlocher syndrome, Leigh syndrome, and a previously published case of FARS2 mutation associated infantile onset disease. The authors also present structure-guided analysis of the relevant mutations based on published mitochondrial phenylalanyl transfer RNA synthetase and related protein crystal structures as well as biochemical analysis of the corresponding recombinant mutant proteins

    Narratives of ethnic identity among practitioners in community settings in the northeast of England

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    The increasing ethnic diversity of the UK has been mirrored by growing public awareness of multicultural issues, alongside developments in academic and government thinking. This paper explores the contested meanings around ethnic identity/ies in community settings, drawing on semi-structured interviews with staff from Children’s Centres and allied agencies conducted for a research project that examined the relationship between identity and the participation of parents/carers in services in northeast England. The research found that respondents were unclear about, especially, white ethnic identities, and commonly referred to other social categorizations, such as age, nationality, and circumstances such as mobility, when discussing service users. While in some cases this may have reflected legitimate attempts to resist overethnicizing non-ethnic phenomena, such constructions coexisted with assumptions about ethnic difference and how it might translate into service needs. These findings raise important considerations for policy and practice

    Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study

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    A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected

    Design, Commissioning and Performance of the PIBETA Detector at PSI

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    We describe the design, construction and performance of the PIBETA detector built for the precise measurement of the branching ratio of pion beta decay, pi+ -> pi0 e+ nu, at the Paul Scherrer Institute. The central part of the detector is a 240-module spherical pure CsI calorimeter covering 3*pi sr solid angle. The calorimeter is supplemented with an active collimator/beam degrader system, an active segmented plastic target, a pair of low-mass cylindrical wire chambers and a 20-element cylindrical plastic scintillator hodoscope. The whole detector system is housed inside a temperature-controlled lead brick enclosure which in turn is lined with cosmic muon plastic veto counters. Commissioning and calibration data were taken during two three-month beam periods in 1999/2000 with pi+ stopping rates between 1.3*E3 pi+/s and 1.3*E6 pi+/s. We examine the timing, energy and angular detector resolution for photons, positrons and protons in the energy range of 5-150 MeV, as well as the response of the detector to cosmic muons. We illustrate the detector signatures for the assorted rare pion and muon decays and their associated backgrounds.Comment: 117 pages, 48 Postscript figures, 5 tables, Elsevier LaTeX, submitted to Nucl. Instrum. Meth.
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