The Experts below are selected from a list of 283233 Experts worldwide ranked by ideXlab platform
Zhaolun Fang - One of the best experts on this subject based on the ideXlab platform.
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an efficient flow injection on line Dilution system for flame atomic absorption spectrometry based on micro zone penetration
Microchemical Journal, 1994Co-Authors: Zhaolun FangAbstract:Abstract Flow injection microsampling Dilution was combined with the zone penetration technique to produce an on-line Dilution system capable of achieving 27,000-fold Dilutions in flame atomic absorption spectrometric determinations with a sampling frequency of 45/h and a precision of better than 2% r.s.d. Readouts were made at the valleys between two sequentially injected micro-sample zones in the microliter range which penetrated each other. The method was applied to the determination of several grams per liter of magnesium in brine solutions without further Dilutions.
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expansion of dynamic range of flame atomic absorption spectrometry by an efficient flow injection Dilution system based on dispersion of microliter volume samples
Analytical Chemistry, 1993Co-Authors: Zhaolun Fang, Bernhard Welz, Michael R SperlingAbstract:An automatic on-line flow injection Dilution system for flame atomic absorption spectrometry was developed based on the injection of low- and submicroliter sample volumes and their dispersion in a mixing coil. Precise control of volumes was possible using computer-controlled stepper motor-driven peristaltic pumps and small-bore Neoprene pump tubes. A more than 1000-fold Dilution with a precision of better than 2% (rsd) (n=15) was achieved using a sample volume of 0.7 μL and a mixing coil of 160-cm length and 1.3-mm i.d. Precision improved to 0.5-0.6% (rsd) when sampling times longer than 2 s were used. Sampling frequencies of 60-100/h, even for the highest Dilutions, made the system highly compatible with routine application
Michael R Sperling - One of the best experts on this subject based on the ideXlab platform.
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expansion of dynamic range of flame atomic absorption spectrometry by an efficient flow injection Dilution system based on dispersion of microliter volume samples
Analytical Chemistry, 1993Co-Authors: Zhaolun Fang, Bernhard Welz, Michael R SperlingAbstract:An automatic on-line flow injection Dilution system for flame atomic absorption spectrometry was developed based on the injection of low- and submicroliter sample volumes and their dispersion in a mixing coil. Precise control of volumes was possible using computer-controlled stepper motor-driven peristaltic pumps and small-bore Neoprene pump tubes. A more than 1000-fold Dilution with a precision of better than 2% (rsd) (n=15) was achieved using a sample volume of 0.7 μL and a mixing coil of 160-cm length and 1.3-mm i.d. Precision improved to 0.5-0.6% (rsd) when sampling times longer than 2 s were used. Sampling frequencies of 60-100/h, even for the highest Dilutions, made the system highly compatible with routine application
Bernhard Welz - One of the best experts on this subject based on the ideXlab platform.
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expansion of dynamic range of flame atomic absorption spectrometry by an efficient flow injection Dilution system based on dispersion of microliter volume samples
Analytical Chemistry, 1993Co-Authors: Zhaolun Fang, Bernhard Welz, Michael R SperlingAbstract:An automatic on-line flow injection Dilution system for flame atomic absorption spectrometry was developed based on the injection of low- and submicroliter sample volumes and their dispersion in a mixing coil. Precise control of volumes was possible using computer-controlled stepper motor-driven peristaltic pumps and small-bore Neoprene pump tubes. A more than 1000-fold Dilution with a precision of better than 2% (rsd) (n=15) was achieved using a sample volume of 0.7 μL and a mixing coil of 160-cm length and 1.3-mm i.d. Precision improved to 0.5-0.6% (rsd) when sampling times longer than 2 s were used. Sampling frequencies of 60-100/h, even for the highest Dilutions, made the system highly compatible with routine application
Tomi T Niemi - One of the best experts on this subject based on the ideXlab platform.
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effect of the combination of mannitol and ringer acetate or hydroxyethyl starch on whole blood coagulation in vitro
Journal of Neurosurgical Anesthesiology, 2010Co-Authors: Annchristine Lindroos, Alexey Schramko, Paivi Tanskanen, Tomi T NiemiAbstract:Mannitol is administered to decrease the intracranial pressure and to improve surgical conditions during craniotomy. Simultaneously a crystalloid infusion is always given and sometimes hydroxyethyl starch (HES) is indicated for intravascular volume replacement. As normal coagulation profile is required during craniotomy, we aimed at determining the effect of mannitol with or without HES or Ringer acetate on blood coagulation in this randomized cross-over in vitro study. Blood samples were withdrawn from 10 volunteers. From whole blood we prepared 10 vol.% and 20 vol.% Dilutions of mannitol (15% Mannitol) alone, mannitol and Ringer acetate, and mannitol and HES 130/0.4 (Voluven) at a ratio of 1:1. Blood samples were analyzed by modified thromboelastometry. Coagulation parameters: clotting time, clot formation time, and maximum clot firmness (MCF), were registered. Clot formation time was prolonged in all Dilutions compared with control (P<0.05). MCF decreased in all Dilutions compared with control (P<0.05). MCF in 20 vol.% Dilution of mannitol with HES was lower than MCF in the corresponding Dilution with Ringer acetate (P<0.05). Fibrinogen-dependent MCF in 10 vol.% Dilution of mannitol with HES was lower than MCF in the corresponding Dilution with Ringer acetate (P<0.05). We conclude that mannitol in combination with HES 130/0.4 impairs clot propagation and clot strength in vitro. Fibrin clot strength impairment is more pronounced when mannitol is combined with HES than Ringer acetate. Our findings indicate that HES in combination with mannitol should be avoided whenever a disturbance in hemostasis is suspected during craniotomy.
Robert B Belshe - One of the best experts on this subject based on the ideXlab platform.
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dose related effects of smallpox vaccine
The New England Journal of Medicine, 2002Co-Authors: Sharon E Frey, Frances K Newman, John Cruz, Brian W Shelton, Janice M Tennant, Tamara Polach, Alan L Rothman, Jeffrey S Kennedy, Mark Wolff, Robert B BelsheAbstract:Background We conducted a double-blind, randomized trial of three Dilutions of vaccinia virus vaccine in previously unimmunized adults in order to assess the clinical success rates, humoral responses, and virus-specific activity of cytotoxic T cells and interferon-γ–producing T cells. Methods Sixty healthy adults were inoculated intradermally by bifurcated needle with undiluted vaccine (dose, 107.8 plaque-forming units [pfu] per milliliter), a 1:10 Dilution (dose, 106.5 pfu per milliliter), or a 1:100 Dilution (dose, 105.0 pfu per milliliter); there were 20 subjects in each group. The subjects were monitored with respect to vesicle formation (an indicator of successful vaccination), the viral titer at the time of peak lesion formation, antiviral antibodies, and cellular immune responses. Results A vaccinia vesicle developed in 19 of the 20 subjects who received undiluted vaccine (95 percent), 14 of the 20 who received the 1:10 Dilution (70 percent), and 3 of the 20 who received the 1:100 Dilution (15 perc...
