164 research outputs found

    Propofol-Based Procedural Sedation with or without Low-Dose Ketamine in Children

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    Objective Examine comparative dosing, efficacy, and safety of propofol alone or with an initial, subdissociative dose of ketamine approach for deep sedation. Background Propofol is a sedative-hypnotic agent used increasingly in children for deep sedation. As a nonanalgesic agent, use in procedures (e.g., bone marrow biopsies/aspirations, renal biopsies) is debated. Our intensivist procedural sedation team sedates using one of two protocols: propofol-only (P-O) approach or age-adjusted dose of 0.25 or 0.5 mg/kg intravenous ketamine (K + P) prior to propofol. With either approach, an initial induction dose of 1 mg/kg propofol is recommended and then intermittent dosing throughout the procedure to achieve adequate sedation to safely and effectively perform the procedure. Approach: Retrospective evaluation of 754 patients receiving either the P-O or K + P approach to sedation. Results A total of 372 P-O group patients and 382 K + P group. Mean age (7.3 ± 5.5 years for P-O; 7.3 ± 5.4 years for K + P) and weight (30.09 ± 23.18 kg for P-O; 30.14 ± 24.45 kg for K + P) were similar in both groups (p = NS). All patients successfully completed procedures with a 16% combined incidence of hypoxia (SPO2 < 90%). Procedure time was 3 minutes longer for K + P group than P-O group (18.68 ± 15.13 minutes for K + P; 15.11 ± 12.77 minutes for P-O; p < 0.01), yet recovery times were 5 minutes shorter (17.04 ± 9.36 minutes for K + P; 22.17 ± 12.84 minutes for P-O; p < 0.01). Mean total dose of propofol was significantly greater in P-O than in K + P group (0.28 ± 0.20 mg/kg/min for K + P; 0.40 ± 0.26 mg/kg/min for P-O; p < 0.0001), and might explain the shorter recovery time. Conclusion Both sedation approaches proved to be well tolerated and equally effective. Addition of ketamine was associated with reduction in the recovery time, probably explained by the statistically significant decrease in the propofol dose

    Synthesis of Mn0.2Zn0.8Fe2O4 particles by high energy ball milling and their applications

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    Ultra fine Mn0.2Zn0.8Fe2O4 magnetic particles are developed by high energy ball milling technique and investigated for physical properties. The crystalline phase, crystallite size, surface morphology, metal oxide bonding and porosity of these magnetic particles are analyzed. The porosity increases on increasing the grinding period due to decrease in the particle size and crystallinity reduces. The IR spectra measured in the range of 4000-400 cm-1 exhibit symmetric stretching mode of (FeO4) and (ZnO4) tetrahedral at 669.7 cm-1 and 545.6 cm-1. The lattice strain induced by ball milling process has been determined. The porosity plays an important role in chemisorption and physisorption of species on the sites of the particles. This property of these particles has been exploited for the applications of humidity sensor

    Double Perovskite Sr2FeMoO6: A Potential Candidate for Room Temperature Magnetoresistance Device Applications

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    The family of double perovskites first received attention in the 1960s, but the discovery of low field magnetoresistnace (LFMR) and half metallicity of the Sr2FeMoO6 (SFMO) compound was made by Kobayashi et al. in 1998. A fully spin polarized half-metal SFMO (Tc > 400) with excellent magnetoresistance response relatively at small applied fields and high temperatures makes SFMO an ideal candidate for room temperature spintronics applications. Primarily, most of the research work on double perovskites SFMO has been focused on bulk ceramic samples and aimed to understand their structural, magnetic, and magnetotransport properties, along with correlation among them. A material such as SFMO that exhibits a large decrease in resistivity and magnetically order well above room temperature is necessary for the advancement of spintronic devices. If the bulk properties observed could be reproduced in thin films, industrially produced SFMO-based spintronic devices could become a reality. Therefore, the purpose of this chapter is to present the detailed background and descriptions of the double perovskite Sr2FeMoO6 (SFMO) thin films and heterostructures with main emphasis to improve or achieve room temperature magnetoresistance properties especially for room temperature magnetoresistive device applications

    Assessment of sol-gel derived iron oxide substituted 45S5 bioglass-ceramics for biomedical applications

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    Magnetic bioactive glass ceramic (MGC) powders have been synthesized by sol gel route by systematically substituting silicon dioxide with iron oxide in the 45S5 glass composition. Powder x-ray diffraction studies revealed a variation in the percentage of combeite (Ca2_2Na2_2Si3_3O9_9), magnetite (Fe3_3O4_4), and hematite (Fe2_2O3_3) nanocrystalline phases in MGC powders as a function of composition. Zeta potential measurements showed that MGC containing up to 10 wt.% iron oxide formed stable suspensions. Saturation magnetization and heat generation capacity of MGC fluids increased with increase in iron oxide content. Degradation of MGC powders was investigated in phosphate buffer saline (PBS). In vitro bioactivity of the MGC powders taken in pellet form was confirmed by observing the pH variation as well as hydroxyapatite layer (HAp) formation upon soaking in modified simulated body fluid. These studies showed a decrement in overall bioactivity in samples with high iron oxide content due to the proportional decrease in silanol group. Monitoring the proliferation of MG-63 osteoblast cell in Dulbecco's Modified Eagle Medium (DMEM) revealed that MGC with up to 10 wt.% iron oxide exhibited acceptable viability. The systematic study revealed that the MGC with 10 wt.% iron oxide exhibited optimal cell viability, magnetic properties and induction heating capacity which were better than those of FluidMag-CT, which is used for hyperthermia treatment.Comment: 24 pages, 11 figure

    Testing and development of transfer functions for weighing precipitation gauges in WMO-SPICE

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    Weighing precipitation gauges are used widely for the measurement of all forms of precipitation, and are typically more accurate than tipping-bucket precipitation gauges. This is especially true for the measurement of solid precipitation; however, weighing precipitation gauge measurements must still be adjusted for undercatch in snowy, windy conditions. In WMO-SPICE (World Meteorological Organization Solid Precipitation InterComparison Experiment), different types of weighing precipitation gauges and shields were compared, and adjustments were determined for the undercatch of solid precipitation caused by wind. For the various combinations of gauges and shields, adjustments using both new and previously existing transfer functions were evaluated. For most of the gauge and shield combinations, previously derived transfer functions were found to perform as well as those more recently derived. This indicates that wind shield type (or lack thereof) is more important in determining the magnitude of wind-induced undercatch than the type of weighing precipitation gauge. It also demonstrates the potential for widespread use of the previously developed transfer functions. Another overarching result was that, in general, the more effective shields, which were associated with smaller unadjusted errors, also produced more accurate measurements after adjustment. This indicates that although transfer functions can effectively reduce measurement biases, effective wind shielding is still required for the most accurate measurement of solid precipitation

    Montmorrilonite K10 catalyzed efficient synthesis of some 4'-nitrochalcones and their 1, 3, 5-triaryl-2-pyrazolines and in vitro antimicrobial evaluation

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    An expeditious synthesis of some 4´-nitrochalcones (3a-n) and their subsequent facile one-pot transformation to 1, 3,5-triaryl-2-pyrazolines (4a-n) has been carried out using montmorrilonite K10 via microwave mediated solvent free protocol.An emphasis is given to highlighting the greenness of the processes, and a fair comparison is also provided between differentinorganic solid supports as catalysts. Both conventional as well as non-conventional approaches have been explored bycomparing the reaction conditions and yields. The newly synthesized pyrazolines were studied for their in vitro antimicrobialevaluation against bacterial strains Bacillus pumilus and Escherichia coli and fungal strains Aspergillus niger and Penicilliumchrysogenum. Findings of biological evaluation highlighted 4b, 4e, 4j and 4m as potential new leads in the search of newantimicrobial agents. The structures of newly synthesized compounds have been established on the basis of elemental analysisand spectroscopic studies.Fil: Ameta, K. L.. Faculty Of Arts, Science & Commerce, Mody University Of; IndiaFil: Rathore, Nitu S.. Faculty Of Arts, Science & Commerce, Mody University Of; IndiaFil: Kumari, Maya. Faculty Of Arts, Science & Commerce, Mody University Of; IndiaFil: Khyaliya, Priyanka. University of Science and Technology; IndiaFil: Dangi R. R.. Faculty Of Arts, Science & Commerce, Mody University Of; IndiaFil: Parellada, Eduardo Alberto. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica. Cátedra de Química Orgánica III; Argentina. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Neske, Adriana. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica. Cátedra de Química Orgánica III; Argentin

    Analysis of single-Alter-shielded and unshielded measurements of mixed and solid precipitation from WMO-SPICE

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    Precipitation measurements were combined from eight separate precipitation testbeds to create multi-site transfer functions for the correction of unshielded and single-Alter-shielded precipitation gauge measurements. Site-specific errors and more universally applicable corrections were created from these WMO-SPICE measurements. The importance and magnitude of such wind speed corrections were demonstrated.This research was funded by the Korean Ministry of Land, Infrastructure and Transport through a grant (16AWMP-B079625-03) from the Water Management Research Program

    Welcome to Zombieland: Practical and Energy-efficient Memory Disaggregation in a Datacenter

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    In this paper, we propose an effortless way for disaggregating the CPU-memory couple, two of the most important resources in cloud computing. Instead of redesigning each resource board, the disaggregation is done at the power supply domain level. In other words, CPU and memory still share the same board, but their power supply domains are separated. Besides this disaggregation, we make the two following contributions: (1) the prototyping of a new ACPI sleep state (called zombie and noted Sz) which allows to suspend a server (thus save energy) while making its memory remotely accessible; and (2) the prototyping of a rack-level system software which allows the transparent utilization of the entire rack resources (avoiding resource waste). We experimentally evaluate the effectiveness of our solution and show that it can improve the energy efficiency of state-of-the-art consolidation techniques by up to 86%, with minimal additional complexity

    The WMO SPICE snow-on-ground intercomparison: an overview of sensor assessment and recommendations on best practices

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    Comunicación presentada en: TECO-2016 (Technical Conference on Meteorological and Environmental Instruments and Methods of Observation) celebrada en Madrid, del 27 al 30 de septiembre de 2016.One of the objectives of the WMO Solid Precipitation Intercomparison Experiment (SPICE) was to assess the performance and capabilities of automated sensors for measuring snow on the ground (SoG), including sensors that measure snow depth and snow water equivalent (SWE). The intercomparison focused on five snow depth sensors (models SHM30, SL300, SR50A, FLS-CH 10 and USH-8) and two SWE sensors (models CS725 and SSG1000) over two winter seasons (2013/2014 and 2014/2015). A brief discussion of the measurement reference(s) and an example of the intercomparisons are included. Generally, each of the sensors under test operated according to the manufacturer’s specifications and compared well with the site references, exhibiting high correlations with both the manual and automated reference measurements. The use of natural and artificial surface targets under snow depth sensors were examined in the context of providing a stable and representative surface for snow depth measurements. An assessment of sensor derived measurement quality and sensor return signal strength, where available as an output option, were analysed to help explain measurement outliers and sources of uncertainty with the goal of improving data quality and maximizing the sensor capabilities. Finally, where possible, relationships are established between the gauge measurement of solid precipitation and the measurement of snow on the ground. This paper will provide a brief summary of these results with more detail included in the WMO SPICE Final Report
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