1,148 research outputs found

    Determination of iron sucrose (Venofer) or iron dextran (DexFerrum) removal by hemodialysis: an in-vitro study

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    BACKGROUND: Intravenous iron is typically administered during the hemodialysis (HD) procedure. HD patients may be prescribed high-flux (HF) or high-efficiency (HE) dialysis membranes. The extent of iron sucrose and iron dextran removal by HD using HF or HE membranes and by ultrafiltration rate (UFR) is unknown. METHODS: Two in vitro HD systems were designed and constructed to determine the dialyzabiltiy of iron from a simulated blood system (SBS) containing 100 mg iron sucrose or iron dextran (system A) or 1000 mg iron sucrose (system B). Both in vitro systems utilized a 6-L closed-loop SBS system that was subject to 4 different HD conditions conducted over 4 hours: HE membrane + 0 ml/hr UFR; HE membrane + 500 ml/hr UFR; HF membrane + 0 ml/hr UFR; HF membrane + 500 ml/hr UFR. Blood flow and dialysate flow rates were 500 ml/min and 800 ml/min, respectively. The dialysate compartment was a 192-L open system for system A and a 6-L closed-loop system for system B. Samples from the SBS and dialysate compartments were taken at various time points and iron elimination rate and HD clearance was determined. Iron removal from the SBS > 15% was considered clinically significant. RESULTS: The greatest percentage removal from the SBS was 13.5% and -0.03% utilizing system A and B, respectively. Iron sucrose and iron dextran dialysate concentration was below the lower limits of assay (< 2 ppm) for system A. Dialysate recovery of iron was negligible: 0 – 5.4 mg system A and 5.47 – 23.59 mg for system B. Dialyzer type or UFR did not affect iron removal. CONCLUSION: HF or HE dialysis membranes do not remove clinically significant amounts of iron sucrose or dextran formulations over a 4-hour HD session. This effect remained constant even controlling for UFR up to 500 ml/hour. Therefore, iron sucrose and iron dextran are not dialyzed by HE or HF dialysis membranes irrespective of UFR

    Effects of Salinity on Reproduction and Survival of the Calanoid Copepod Pseudodiaptomus Pelagicus

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    Four experiments were conducted on the calanoid copepod, Pseudodiaptomus pelagicus, to determine the effects of salinity on survival, development time, reproductive output, and population growth in order to define the optimal salinity for culture. To determine the appropriate experimental salinity range we exposed nauplii and adults to abrupt salinity changes from 35 g/L to 5, 10, 15, 35, 42, and 48 g/L at 30 °C and determined survival after 24 hours. The second experiment stocked early stage nauplii into 1 L beakers after which they were cultured using standard procedures for 10 days at six salinities (10, 15, 20, 25, 30, 35 g/L); from this survival, sex ratio, time to maturation, and fecundity were measured. The third experiment evaluated the effects of salinity on brood size, brood interval, and nauplii production by stocking individual adult pairs and monitoring nauplii production daily for 10 days. The fourth experiment determined the effects of salinity on population growth and composition of the population produced by stocking 10 adult pairs and culturing them until five days after the first mature adults were observed. Results from the abrupt salinity change experiment showed nauplii survival decreased following abrupt changes in salinity from 35 g/L to \u3c 15 g/L and \u3e 35 g/L. Additionally, adults do not tolerate rapid changes in salinity from 35 g/L to \u3c 15 g/L but are rather tolerant of changes in salinity up to 48 g/L. Survival from early nauplii to adult was not significantly affected by salinity but survival declined at 35 g/L. Time to first maturation and maturation of the entire population was significantly influenced by salinity and took from 6.3 to 9.5 days. In the individual paired adults experiment, salinity significantly affected nauplii production by affecting brood interval and brood size. The percentage of ovigerous females peaked at 20 g/L and declined at salinities above and below this value. When developing production objectives, aquaculturists must consider salinity because of its numerous effects on the culture of P. pelagicus. The optimal salinity range to achieve high survival and the greatest nauplii production is 15–25 g/L

    Cascading the use of Web 2.0 technology in secondary schools in the United Kingdom: identifying the barriers beyond pre-service training

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    This paper reports on research that took place at Nottingham Trent University and Sheffield Hallam University, United Kingdom, over two years. The research focuses on the use of Web 2.0 technology, specifically web logs, with pre-service teachers, both during their university programme and the first year of teaching as full-time newly qualified teachers (NQTs). The purpose of this research was to add a developing body of knowledge by identifying whether technology used by pre-service teachers during their training course can be cascaded into their practice once qualified. Key findings identify a number of enablers and barriers to cascading technology in the classroom; these include curriculum time, pupil skills and support. The research concludes that early professional support and development should be on-going and assumptions about new teachers as champions of cascading innovative use of Web 2 technologies into their practice as NQTs may be over optimisti

    A Factorization Algorithm for G-Algebras and Applications

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    It has been recently discovered by Bell, Heinle and Levandovskyy that a large class of algebras, including the ubiquitous GG-algebras, are finite factorization domains (FFD for short). Utilizing this result, we contribute an algorithm to find all distinct factorizations of a given element f∈Gf \in \mathcal{G}, where G\mathcal{G} is any GG-algebra, with minor assumptions on the underlying field. Moreover, the property of being an FFD, in combination with the factorization algorithm, enables us to propose an analogous description of the factorized Gr\"obner basis algorithm for GG-algebras. This algorithm is useful for various applications, e.g. in analysis of solution spaces of systems of linear partial functional equations with polynomial coefficients, coming from G\mathcal{G}. Additionally, it is possible to include inequality constraints for ideals in the input

    Real driving emissions data : Isuzu FTR850 AMT

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    RDE is becoming a necessary element of the emissions certification of automotive vehicles. Real Driving Emissions (RDE) helps to ensure that the regular operation of a car, or heavy vehicle, is still within the acceptable emissions standards while driving under normal conditions. RDE is monitored by connecting a Portable Emissions Measurement System (PEMS) to the exhaust of the tested vehicle, which measures the pollutant concentrations as the car or truck drives along a standardised route. The data described in this paper is the raw, detailed PEMS records of a heavy goods vehicle, recorded at a rate of 1Hz, over multiple trips on an urban route in South Africa. The data includes the pollutant concentrations of CO, CO2, NO and NO2, ambient conditions, and vehicle diagnostics collected from different sensors mounted to the vehicle during the field tests. We performed no additional analysis on the data. The value of the data is in allowing researchers to (a) develop and test machine learning algorithms that predict the instantaneous pollutant concentrations or (b) studying the variance of pollutant concentrations that occurs under typical driving conditionshttps://www.journals.elsevier.com/data-in-brief/dm2022Industrial and Systems Engineerin

    Determination of vancomycin and gentamicin clearance in an in vitro, closed loop dialysis system

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    Background\ud The purpose of this study was to evaluate the feasibility of utilizing an in-vitro, closed loop hemodialysis system as a method to assess drug clearance. Secondarily, this study tested the influence of variables (blood flow rate, dialysate flow rate, and type of filter) in the hemodialysis procedure on the clearance of vancomycin and gentamicin.\ud \ud Methods\ud An in-vitro, closed loop hemodialysis system was constructed. The vancomycin (30 mg/L) and gentamicin (25 mg/L) were added to a simulated blood system (SBS). Four conditions (C1-C4) were tested by defining the filter (Polyflux 170H or F180) and the blood and dialysate flow rates (BFR and DFR). All hemodialysis sessions were 3 hours in length and each condition was completed in duplicate. Dialysate effluent was collected in a 50 gallon polyethylene drum. Samples were collected (in duplicate) from the SBS and the dialysate effluent at baseline and at the end of the hemodialysis session. Samples were analyzed for vancomycin and gentamicin with an ultrahigh performance liquid chromatography/tandem mass spectrometry method.\ud \ud Results\ud A total of eight 3-hour hemodialysis sessions were conducted. For all tested conditions (C1-C4), vancomycin was undetectable in the SBS at the end of dialysis. However, total vancomycin recovery in the dialysis effluent was 85±18%, suggesting that up to 15% may have adsorbed to the dialysis filter or tubing. Gentamicin clearance from SBS was >98% in all tested conditions. Average gentamicin recovery in the dialysate effluent was 99±15%.\ud \ud Conclusion\ud Both vancomycin and gentamicin were readily removed by high-flux hemodialysis under all conditions studied. No significant differences in drug clearance were observed between conditions used in this in vitro study. The clinical implications of changing these hemodialysis parameters are unknown

    Chinese L2 learners’ depth of vocabulary knowledge and its role in reading comprehension

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Using a Chinese Word Associates Test (WAT-C), this study examined the vocabulary depth of second language learners of Chinese and its contribution to the learners’ reading comprehension. Results showed no significant effects of word frequency, word class (i.e., adjectives vs. verbs), and type of association relationships (i.e., paradigmatic vs. syntagmatic) on learners’ WAT-C performance. More important, vocabulary depth was found to be a significant and unique predictor of reading comprehension over and above vocabulary size. On the other hand, the relative contributions of vocabulary depth and size depended on what types of texts were read and what comprehension skills were assessed. Specifically, for the long passage comprehension task with questions testing literal comprehension, vocabulary size was a more important predictor, whereas for the short passage comprehension task with questions testing inferencing, vocabulary depth was a more important predictor. These findings were discussed in light of the different levels of lexical complexity between the short and long passages and the different cognitive processing demands the questions of the two comprehension tasks placed on learners

    Satellite Remote Sensing of Atmospheric SO_2: Volcanic Eruptions and Anthropogenic Emissions

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    In this article, we present satellite data analysis of atmospheric Sulfur Dioxide (SO_2) from volcanic eruptions and anthropogenic activities. Data from Global Ozone Monitoring Experiment (GOME) on board ERS-2 for the years 1996 to 2002 is analyzed using a DOAS based algorithm with the aim of retrieving SO_2 Slant Column Densities (SCDs). Difficulties in the retrieval of SO_2 SCDs due to instrumental effects are investigated in detail and significantly improved. The retrieved SCDs can be used to identify and monitor several volcanic eruptions. A brief introduction of different volcanic eruptions around the globe is presented Also informations about the anthropogenic SO_2 emissions can be easily achieved from the retrieved data set. A time series of anthropogenic SO_2 emissions over Eastern Europe is presented in this study. The time series showed high SO_2 SCDs over Eastern Europe during the winter months. The results demonstrate a high sensitivity of GOME instrument towards SO_2 emissions
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