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Sample records for plasma samples obtained

  1. The possibilities of atmospheric plasma-spraying application to obtain hydroxyapatite coatings on the stainless steel samples

    Directory of Open Access Journals (Sweden)

    Mihailović Marija D.

    2013-01-01

    Full Text Available For decades, the standard metallic materials for hip implants, besides the 316LVM stainless steel, were titanium- and cobalt/chromium-based alloys. Although bioinert, due to their corrosion resistance, they are not biocompatible. Contemporary surgical implants are not made just of bioinert metal anymore, but with deposited bioactive hydroxyapatite (HAp coating. Hydroxyapatite is chemically identical with the mineral constituent of bones and teeth, what besides its biocompatibility provides bioactivity as well. The HAp limitations are, however, weak tensile strength and low fatigue resistance for long term loadings, if used alone. This is the reason for HAp to be deposited onto the surgical implant, and to enable its bioactivity, what means intergrowth with bones, and therefore the long-lasting and mechanical stable non-cemented prosthesis. This is important predominantly because the need for such prostheses for younger population, and a better life quality. There are several contemporary techniques that have been used for deposition of these coatings onto the metal implant. The possibilities of atmospheric plasma-spraying for obtaining the stable HAp coatings on the 316LVM stainless steel, ordinary used as a standard material for hip implants production are presented in this paper. The coatings of a commercially available hydroxyapatite powder were plasma-sprayed onto the specimens of medical grade 316LVM stainless steel under various operating conditions. The optical microscopy was used for microstructure and porosity characterization, while coating morphology and Ca/P ratio were analyzed using SEM equipped with EDX. Coating microstructure varied from a porous to a glassy structure, depending on operating conditions applied and coating thickness. Coating porosity was determined to be at the lower required limit requested for the bone-coating intergrowth possibility, but nevertheless adhesion measurements showed good results. The Ca/P ratio was

  2. Hardness evaluation, stoichiometry and grain size of titanium nitride films obtained with plasma nitriding on Ti-6Al-4V samples

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcellos, Marcos Antonio Zen; Lima, Saulo Cordeiro; Hinrichs, Ruth [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre (Brazil)

    2010-07-01

    Titanium nitride films were formed on the surface of Ti-6Al-4V discs by plasma nitriding (glow discharge) in different N{sub 2}:H{sub 2} atmospheres at several substrate temperatures. In this study the influence of the process parameters on dynamic micro-hardness were investigated. Grain sizes of the nitride films, determined with X Ray Diffraction, were related to the nitriding parameters. TiNx stoichiometry was determined with Nuclear Reaction Analysis and showed a correlation to substrate temperature during the nitriding process. Micro-hardness measurements were taken on the nitrided surfaces. Grain sizes increased for a particular gas composition of 60%N{sub 2}+40%H{sub 2} where hardness was lowest. (author)

  3. The determination of phenazone in blood plasma for obtained sistem suitable test of monitoring drug level

    OpenAIRE

    Mochamad Lazuardi

    2007-01-01

    The determining of Phenazone to human blood plasma from healthy man after separated by solid phase extraction (SPE) and spectroscopic measurements has been investigated. The objective of that research was to obtain system suitable test for determine the Phenazone level in biological fluids (human blood plasma), for new performed dosage regimented in clinical dentistry. The method can be divided into the following four steps. 1. Centrifugation the blood sample, 2. Extraction from blood plasma ...

  4. Morphology, Structure and Biodegradability of Hollow HA Microspheres Obtained by Plasma Spraying

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The spraying-dried HA (ASD) was employed. ASD was plasma-sprayed onto ice to obtain hollow HA microspheres. The particle size of the sample was determined with a particle size analyzer. The morphology and structure of the samples were measured by scanning electron microscope and X-ray powder diffraction.The in vitro biodegradability of samples was evaluated by immersion tests in Ringer' s solution (RS) and simulated body fluid ( SBF). The samples were immersed respectively in RS and SBF for a period. The Ca2+ ion concentration in the solutions was determined by Atomic Adsorption Spectrum. By plasma spraying hollow HA microspheres were obtained. The hollow microspheres consisted mainly of low crystalline and amorphous HA, and had better biodegradability.

  5. Surface studies of plasma processed Nb samples

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Puneet V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Doleans, Marc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Hannah, Brian S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Afanador, Ralph [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Stewart, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Mammosser, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Howell, Matthew P [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Saunders, Jeffrey W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Degraff, Brian D [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Kim, Sang-Ho [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

    2015-01-01

    Contaminants present at top surface of superconducting radio frequency (SRF) cavities can act as field emitters and restrict the cavity accelerating gradient. A room temperature in-situ plasma processing technology for SRF cavities aiming to clean hydrocarbons from inner surface of cavities has been recently developed at the Spallation Neutron Source (SNS). Surface studies of the plasma-processed Nb samples by Secondary ion mass spectrometry (SIMS) and Scanning Kelvin Probe (SKP) showed that the NeO2 plasma processing is very effective to remove carbonaceous contaminants from top surface and improves the surface work function by 0.5 to 1.0 eV.

  6. Bacterial contamination in cold water samples obtained from water dispensers.

    Science.gov (United States)

    Furuhata, Katsunori; Ishizaki, Naoto; Fukuyama, Masafumi

    2015-01-01

    We carried out a basic study in order to evaluate the bacterial contamination in water dispensers. Water samples were obtained from water dispensers from October 2012 to November 2013, and standard plate counts (at 36˚C, 24 h) of the samples, as well as heterotrophic plate counts (at 25˚C, 7 d), were estimated with the standard methods for the examination of drinking water in Japan. Standard plate counts exceeding the water-quality standard (1.0×10(2) CFU/ml) were observed in 42 of the 140 samples (30.0%), with a maximum detected bacterial count of 2.1×10(5) CFU/ml. The rate of the standard plate counts exceeding the water quality standard tended to be higher when using a one-way type method or water dispensers with natural water. Ralstonia spp. was most commonly isolated, and Pseudomonas aeruginosa was isolated in a few cases. Some opportunistic pathogens were also isolated, suggesting that we should be more concerned about bacterial contamination in cold water supplied from water dispensers.

  7. Impact of cleaning before obtaining midstream urine samples from children

    DEFF Research Database (Denmark)

    Lytzen, Rebekka; Knudsen, Jenny Dahl; Ladelund, Steen

    2014-01-01

    24 h. In 2004-2006 ("cleaning period"), 523 children were cleaned before obtaining two MSUs, contrary to the 1,335 children included in 2008-2010 ("non-cleaning period"). Significant bacteriuria was defined as at least 10,000 colony-forming units/ml of the same uropathogenic bacterium in two MSUs...... in monoculture. Contamination was defined as all other microbiological findings. RESULTS: The procedure of no cleaning before sampling increased the risk of contamination in 0-9.9-year-old children from 43% to 49% (p = 0.034); and specifically in 0-9.9-year-old girls, the risk of contamination increased from 47...... than ten years of age is recommended to minimise the risk of contamination. Cleaning was without effect on children aged 10-15 years. FUNDING: not relevant. TRIAL REGISTRATION: not relevant....

  8. Blood sampling and hemolysis affect concentration of plasma metabolites

    DEFF Research Database (Denmark)

    Theil, Peter Kappel; Pedersen, Lene Juul; Jensen, Margit Bak;

    2012-01-01

    , a subset of samples from 24 sows fed twice daily in Exp. 1 was combined with data obtained from 30 sows sampled using jugular vein catheters. All sows in Exp. 2 were fed twice daily (0800 h and 1500 h) and blood samples collected repeatedly 1, 4, 11, and 23 h after morning feeding (other conditions were......Two experiments were carried out to reveal and quantify plasma metabolites that are sensitive to hemolysis and animal stress due to the blood sampling procedure (vein puncture vs. catheter). In Exp. 1, 48 sows were fed 4 diets either once (0800 h) or twice daily (0800 h and 1500 h) in a crossover...... design and blood was collected after restraint via vein puncture 1, 4, 11, and 23 h after morning feeding. Plasma samples were categorized as without or with minor or major hemolysis [clear (n = 218), yellow (n = 97), or red (n = 37)] upon centrifugation. Plasma NEFA (P

  9. Biofouling development on plasma treated samples versus layers coated samples

    Science.gov (United States)

    Hnatiuc, B.; Exnar, P.; Sabau, A.; Spatenka, P.; Dumitrache, C. L.; Hnatiuc, M.; Ghita, S.

    2016-12-01

    Biofouling is the most important cause of naval corrosion. In order to reduce the Biofouling development on naval materials as steel or resin, different new methods have been tested. These methods could help to follow the new IMO environment reglementations and they could replace few classic operations before the painting of the small ships. The replacement of these operations means a reduction in maintenance costs. Their action must influence especially the first two steps of the Biofouling development, called Microfouling, that demand about 24 hours. This work presents the comparative results of the Biofouling development on two different classic naval materials, steel and resin, for three treated samples, immersed in sea water. Non-thermal plasma, produced by GlidArc technology, is applied to the first sample, called GD. The plasma treatment was set to 10 minutes. The last two samples, called AE9 and AE10 are covered by hydrophobic layers, prepared from a special organic-inorganic sol synthesized by sol-gel method. Theoretically, because of the hydrophobic properties, the Biofouling formation must be delayed for AE9 and AE10. The Biofouling development on each treated sample was compared with a witness non-treated sample. The microbiological analyses have been done for 24 hours by epifluorescence microscopy, available for one single layer.

  10. Impact of cleaning before obtaining midstream urine samples from children

    DEFF Research Database (Denmark)

    Lytzen, Rebekka; Knudsen, Inge Jenny Dahl; Ladelund, Steen

    2014-01-01

    24 h. In 2004-2006 ("cleaning period"), 523 children were cleaned before obtaining two MSUs, contrary to the 1,335 children included in 2008-2010 ("non-cleaning period"). Significant bacteriuria was defined as at least 10,000 colony-forming units/ml of the same uropathogenic bacterium in two MSUs...

  11. Platinum and Iridium Coatings Obtained by Double Glow Plasma Technology

    Institute of Scientific and Technical Information of China (English)

    WU Wangping; CHEN Zhaofeng; CHEN Zhou; CONG Xiangna; QIU Jinlian

    2012-01-01

    Pt and Ir coatings were produced by double glow plasma technology on the surface of Ti alloy substrates.The chemical compositions of the coatings were determined by X-ray diffraction and X-ray photoelectron spectroscopy.The microstructure and morphology of the coatings were observed by scanning electron microscopy.The hardness and elastic modulus of the coatings were estimated by nanoindentation.The measurements of adhesive forces of the coatings were performed with scratch tester.The results indicated that the Pt and Ir coatings displayed the preferred (220) orientation due to the initial nuclei with preferred growth on the surface of the substrates.The interface between the Pt coating and substrate exhibited no evidence of delamination.The Ir coating was composed of irregular columnar grains with many nanovoids at the interface between the coating and substrate.The mean values of hardness for Pt and Ir coatings were 0.9 GPa and 9 GPa,respectively.The elastic modulus of Pt and Ir coatings were 178 GPa and 339 GPa,respectively.The adhesive forces of the Pt and Ir coatings were about 66.4 N and 55 N,respectively.The Pt and Ir coatings adhered well to the Ti alloy substrates.

  12. The determination of phenazone in blood plasma for obtained sistem suitable test of monitoring drug level

    Directory of Open Access Journals (Sweden)

    Mochamad Lazuardi

    2007-09-01

    Full Text Available The determining of Phenazone to human blood plasma from healthy man after separated by solid phase extraction (SPE and spectroscopic measurements has been investigated. The objective of that research was to obtain system suitable test for determine the Phenazone level in biological fluids (human blood plasma, for new performed dosage regimented in clinical dentistry. The method can be divided into the following four steps. 1. Centrifugation the blood sample, 2. Extraction from blood plasma and, 3. Separation by SPE with manual pressured, 4. Elution to SPE followed by the measurement on a spectrophotometer in the ultra violet region. The critical value of  │t │at the 5% confidence level indicates that there is no systematic error in the linearity proposed method. Recoveries for this research were obtained at ranging 93.460 to 95.598%. The coefficient variation precision of this procedure was clearly good at smallest than 2%. The analytical procedure can be carried out in one working operation as a monitored therapeutic activity.

  13. Seminal plasma protein profiles of ejaculates obtained by internal artificial vagina and electroejaculation in Brahman bulls.

    Science.gov (United States)

    Rego, J P A; Moura, A A; Nouwens, A S; McGowan, M R; Boe-Hansen, G B

    2015-09-01

    The present study was conducted to investigate if differences exist in the seminal plasma protein profile from mature Brahman bulls using two methods of semen collection: internal artificial vagina (IAV) and electroejaculation (EEJ). Semen was collected four times from three bulls on the same day and parameters were assessed immediately post-collection. Seminal plasma proteins were evaluated by 2-D fluorescence difference gel electrophoresis and identified by mass spectrometry. Semen volume was greater (P < 0.05) for EEJ (4.6 ± 0.35 mL) than for IAV (1.86 ± 0.24 mL) but sperm concentration was greater in IAV (1505 ± 189 × 10(6) sperm/mL) than in EEJ samples (344 ± 87 × 10(6) sperm/mL). Sperm motility and the percentage of normal sperm were not different between treatments. Total concentration of seminal plasma proteins was greater for samples collected by IAV as compared to EEJ (19.3 ± 0.9 compared with 13.0 ± 1.8 mg/mL, P < 0.05; respectively). Based on 2-D gels, 22 spots had a greater volume (P < 0.05) in gels derived from IAV samples, corresponding to 21 proteins identified as transferrin, albumin, epididymal secretory glutathione peroxidase, among others. Thirty-three spots, corresponding to 26 proteins, had a greater volume (P < 0.05) in gels derived from EEJ samples. These proteins were identified as spermadhesin-1, Bovine Sperm Protin 1, 3 and 5 isoforms, angiogenin-1, alpha-1B-glycoprotein, clusterin, nucleobindin-1, cathepsins, spermadhesin Z13, annexins, among others. Thus, proteins in greater amounts in samples obtained by IAV and EEJ were mainly of epididymal origin and accessory sex glands, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Neutron angular distribution in a plasma focus obtained using nuclear track detectors.

    Science.gov (United States)

    Castillo-Mejía, F; Herrera, J J E; Rangel, J; Golzarri, J I; Espinosa, G

    2002-01-01

    The dense plasma focus (DPF) is a coaxial plasma gun in which a high-density, high-temperature plasma is obtained in a focused column for a few nanoseconds. When the filling gas is deuterium, neutrons can be obtained from fusion reactions. These are partially due to a beam of deuterons which are accelerated against the background hot plasma by large electric fields originating from plasma instabilities. Due to a beam-target effect, the angular distribution of the neutron emission is anisotropic, peaked in the forward direction along the axis of the gun. The purpose of this work is to illustrate the use of CR-39 nuclear track detectors as a diagnostic tool in the determination of the time-integrated neutron angular distribution. For the case studied in this work, neutron emission is found to have a 70% contribution from isotropic radiation and a 30% contribution from anisotropic radiation.

  15. Genetic distance sampling: a novel sampling method for obtaining core collections using genetic distances with an application to cultivated lettuce

    NARCIS (Netherlands)

    Jansen, J.; Hintum, van T.J.L.

    2007-01-01

    This paper introduces a novel sampling method for obtaining core collections, entitled genetic distance sampling. The method incorporates information about distances between individual accessions into a random sampling procedure. A basic feature of the method is that automatically larger samples are

  16. Optical and biological properties of transparent nanocrystalline hydroxyapatite obtained through spark plasma sintering.

    Science.gov (United States)

    Li, Zhong; Thompson, Brianna C; Dong, Zhili; Khor, Khiam Aik

    2016-12-01

    Transparent bioceramics have attracted a large amount of research interest as they facilitate direct observation of biointerfacial reactions. Thus far, attempts to achieve transparent hydroxyapatite have been focused on augmenting the sintering pressure and/or extending the sintering duration. This study aims at fabricating transparent HA using a direct and fast spark plasma sintering process with appropriate starting powder and moderate sintering pressure. Three types of raw powder, namely micro-spheres, nano-rods and nano-spheres, were sintered to investigate the optical and biological properties of the compacted pellets. It was found that in terms of transparency, the micro-sphere pellet sintered at 1000°C stood out with an in-line transmittance as high as 84% achieved at 1300nm for a 2mm thick sample. In addition, pellets fabricated from micro-spheres demonstrated the highest cell viability in in vitro biological tests with L929 cells. Living cells cultured on a transparent micro-sphere pellet could be directly and clearly observed by light microscopy. It is thus concluded that the micro-sphere powder is the most desirable raw material to manufacture transparent hydroxyapatite because it could enable dense pellets with notably high transparency and outstanding in vitro biocompatibility to be readily obtained.

  17. Modulation of endothelial monolayer permeability induced by plasma obtained from lipopolysaccharide-stimulated whole blood.

    NARCIS (Netherlands)

    Nooteboom, A.; Bleichrodt, R.P.; Hendriks, T.

    2006-01-01

    The aim of this study was to elucidate the time course of the permeability response of endothelial monolayers after exposure to plasma obtained from lipopolysaccharide (LPS)-treated human whole blood; to investigate the role of apoptosis in monolayer permeability, and to inhibit the permeability inc

  18. [POSSIBILITY OF OBTAINING ALLOGENEIC ANTIMENINGOCOCCUS FRESH FROZEN PLASMA AND CONTROL OF ITS QUALITY INDICATORS].

    Science.gov (United States)

    Tereshchuk, T O

    2015-01-01

    Results of the study identifying the titer of natural antimeningococcus antibodies serogroup B of non-immunized donor population of Zhytomyr Region aged 18-54 years, all AB0 blood groups are presented for further use of these results in the organization of the immune donation. Indicators of quality of antimeningococcus fresh frozen plasma obtained by different methods are characterized.

  19. The influence of heating rate on superconducting characteristics of MgB2 obtained by spark plasma sintering technique

    Science.gov (United States)

    Aldica, G.; Burdusel, M.; Popa, S.; Enculescu, M.; Pasuk, I.; Badica, P.

    2015-12-01

    Superconducting bulks of MgB2 were obtained by the Spark Plasma Sintering (SPS) technique. Different heating rates of 20, 100, 235, 355, and 475 °C/min were used. Samples have high density, above 95%. The onset critical temperature Tc, is about 38.8 K. There is an optimum heating rate of ∼100 °C/min to maximize the critical current density Jc0, the irreversibility field Hirr, the product (Jc0 x μ0Hirr), and to partially avoid formation of undesirable flux jumps at low temperatures. Significant microstructure differences were revealed for samples processed with low and high heating rates in respect to grain boundaries.

  20. Plasma methods of obtainment of multifunctional composite materials, dispersion-hardened by nanoparticles

    Science.gov (United States)

    Sizonenko, O. N.; Grigoryev, E. G.; Zaichenko, A. D.; Pristash, N. S.; Torpakov, A. S.; Lipyan, Ye V.; Tregub, V. A.; Zholnin, A. G.; Yudin, A. V.; Kovalenko, A. A.

    2016-04-01

    The new approach in developed plasma methods consists in that dispersionhardening additives (TiC, TiB2 in particular) are not mechanically added to powder mixture as additional component, as in conventional methods, but are instead synthesized during high voltage electric discharges (HVED) in disperse system “hydrocarbon liquid - powder” preservation of ultrafine structure is ensured due to use of spark plasma sintering (SPS) as a consolidation method. HVED in disperse system “hydrocarbon liquid - powder” due to impact of plasma discharge channel, electromagnetic fields, shock waves mechanical impact, hydro flows and volume microcavitation leads to synthesis of nanocarbon, metal powders dispersion and synthesis of micro- (from 10-6 to 10-7 m) and nanosized (from 10-7 to 10-9 m) composite powders of hardening phases. SPS is the passage of pulsed current (superposition of direct and alternating current) through powder with the simultaneous mechanical compressing. The formation of plasma is initiated in gaseous phase that fills gaps between particles. SPS allows targeted control of grain growth rate and thus allows obtainment of multifunctional composite materials dispersion hardened by nanoparticles. Processes of HVED synthesis of micro- and nanosized powders of new compositions from elemental metal powders and their mixtures with the subsequent application of high-speed SPS of obtained powders create conditions for increase of strength (by 10 - 20%), hardness and wear-resistance (by 30 - 60%) of obtained materials.

  1. NUTRITIONAL AND MICROBIOLOGICAL COMPONENTS OF HONEY SAMPLES OBTAINED FROM OGUN STATE, SOUTHWESTERN NIGERIA

    Directory of Open Access Journals (Sweden)

    M. O. ADENEKAN

    2012-06-01

    Full Text Available There are no detailed studies on the nutritional and microbiological characteristics of honeyproduced in Ogun State in the Southwestern part of Nigeria. This paper investigated thesecomponents in honeys produced from different parts of this state. A total of 10 honey samples peryear were collected for the years 2008 – 2010. These were separately analyzed for their physicalproperties, nutritional and microbiological components in the laboratory. The results of thephysical properties showed that honey samples obtained from Ago-Iwoye has the lowest pH of3.48, which was significantly different from the pH values of 5.06, 5.21 and 4.06 obtained fromhoney samples from Abeokuta, Ibefun and Ilisan honey samples respectively. There wassignificant difference in moisture contents of honey samples obtained from Ogere (16.19 %, Otta(19.14 % and Ijebu-Ode (18.21 %, while the percentage ash contents of 0.78 % obtained fromhoney samples collected from Abeokuta was not significantly different from the value of 0.75 %obtained from Ago-Iwoye honey (P ≤ 0.05. However, the value of 1.11 mg 100 g-1 forhydroxymethylfurfural obtained from Ago-Iwoye honey samples was not significantly differentfrom the value of 0.32 mg 100 g-1 in honey samples obtained from Sagamu.The value for glucose ranged from 18.42 – 30.16 g 100 g-1, while fructose sugar varied between25.42 – 38.21 g 100 g-1. Minimum protein value of 0.02 % was obtained from Ijebu-Ode honey,while the maximum of 0.51 % was obtained from honey samples from Ilisan. Results of theelemental nutrient showed that potassium was the most abundant element in honey samples withthe range value of 14.78 – 17.42 mg 100 g-1 followed by calcium, which varied from 2.13 – 11.25mg 100 g-1. However, result of microbiological properties showed that the total plate count variedfrom 0.2 – 3.4 cfu g-1, whereas total coliforms were not detected in honey samples collected fromAgo-Iwoye, Otta, Ibefun, Ife and Sagamu

  2. Friction of tungsten carbide-cobalt coatings obtained by means of plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Cartier, M. (Hydromecanique et Frottement, Centre de Recherches, 42 - Andreziux-Boutheon (France)); McDonnell, L.; Cashell, E.M. (CRTC, Cork (Ireland))

    1991-11-29

    A study of the frictional properties of WC-Co-type coatings obtained by plasma spraying was carried out, the influence of the majority of the parameters involved in atmospheric spraying being analysed. This study of the correlations between the tribological behaviour and the compositionl of the coatings shows that friction is mainly determined by the method and degree of decomposition of the carbides. These in turn are linked to the effects of heat and/or oxidation, factors which can change considerably, not only as a function of the method used (plasma power, nature and flow rate of the plasma gases etc.) but also as a function of the coating process and the composition of the original powders. It has been possible to correlate the improvement in the frictional properties (resistance to seizure, reduction in the coefficient of friction) with the presence of free carbon in the coatings, associated with the carbide decomposition process. (orig.).

  3. Comparative performance of the protocol of plasma rich in growth factors - universal 1 (PRGF-U1 for obtaining platelet rich plasma.

    Directory of Open Access Journals (Sweden)

    Augusto Aguirre

    2017-01-01

    Full Text Available Objective: To compare the platelet concentration obtained after application of the protocol of plasma rich in growth factors - universal 1 (PRGF-U1 and the protocol of Anitua and Andia (PRP-A for obtaining platelet rich plasma. Material and Method: A descriptive, cross-sectional and comparative study was carried out with a simple random probabilistic sample consisting of 16 patients who attended the Periodontics service of the Unit of Second Specialization in Stomatology of the National University of Trujillo. Five blood samples were obtained from each patient, after applying a health questionnaire to rule out any disease or drug consumption, in order to obtain the baseline platelet concentration and that obtained after PRGF-U1 and PRP-A. To compare the platelet concentrations of the two protocols, Student’s t-test was used considering a significance level of p<0.05. RESULTS: The baseline platelet concentration was 371,250±68,203 platelets/μL, for PRGF-U1 it was 747,875±121,645 platelets/μL and for PRP-A it was 595,000±129,202 platelets/μL. A statistically significant difference (p<0.001 was found between both protocols. Conclusion: The PRGF-U1 protocol yielded a higher platelet concentration compared to the Anitúa and Andía protocol.

  4. Highly stable hydrophilic surfaces of PDMS thin layer obtained by UV radiation and oxygen plasma treatments

    Energy Technology Data Exchange (ETDEWEB)

    Menezes Atayde, Cleuson de; Doi, Ioshiaki [Center for Semiconductor Components, University of Campinas - UNICAMP, Campinas, SP (Brazil); School of Electrical and Computer Engineering, University of Campinas - UNICAMP, Campinas, SP (Brazil)

    2010-02-15

    Surface modification of polydimethylsiloxane (PDMS, Sylgard 184) was carried out by O{sub 2} plasma and UV in broadband mode/O{sub 2} plasma treatments with different exposure times, and studied in terms of hydrophilic stability. Water contact angle measurements, Fourier Transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used for the analysis of the modified surface and hydrophilic stability of the PDMS films. The results show reasonably good hydrophilic stability in the range of a week with a contact angle of around 70 for O{sub 2} plasma treated samples, whereas a more high hydrophilic stability, with a low contact angle of 65 up to 15 days, was observed for UV/O{sub 2} plasma treated PDMS. FTIR analysis of the samples reveals significant oxidation noted by large presence of Si-O-Si, and Si-OH bonds on the PDMS surface, which improves the affinity with water molecules and increases the hydrophilicy. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Ion sampling and transport in Inductively Coupled Plasma Mass Spectrometry

    Science.gov (United States)

    Farnsworth, Paul B.; Spencer, Ross L.

    2017-08-01

    Quantitative accuracy and high sensitivity in inductively coupled plasma mass spectrometry (ICP-MS) depend on consistent and efficient extraction and transport of analyte ions from an inductively coupled plasma to a mass analyzer, where they are sorted and detected. In this review we examine the fundamental physical processes that control ion sampling and transport in ICP-MS and compare the results of theory and computerized models with experimental efforts to characterize the flow of ions through plasma mass spectrometers' vacuum interfaces. We trace the flow of ions from their generation in the plasma, into the sampling cone, through the supersonic expansion in the first vacuum stage, through the skimmer, and into the ion optics that deliver the ions to the mass analyzer. At each stage we consider idealized behavior and departures from ideal behavior that affect the performance of ICP-MS as an analytical tool.

  6. Tungsten nitride coatings obtained by HiPIMS as plasma facing materials for fusion applications

    Science.gov (United States)

    Tiron, Vasile; Velicu, Ioana-Laura; Porosnicu, Corneliu; Burducea, Ion; Dinca, Paul; Malinský, Petr

    2017-09-01

    In this work, tungsten nitride coatings with nitrogen content in the range of 19-50 at% were prepared by reactive multi-pulse high power impulse magnetron sputtering as a function of the argon and nitrogen mixture and further exposed to a deuterium plasma jet. The elemental composition, morphological properties and physical structure of the samples were investigated by Rutherford backscattering spectrometry, atomic force microscopy and X-ray diffraction. Deuterium implantation was performed using a deuterium plasma jet and its retention in nitrogen containing tungsten films was investigated using thermal desorption spectrometry. Deuterium retention and release behaviour strongly depend on the nitrogen content in the coatings and the films microstructure. All nitride coatings have a polycrystalline structure and retain a lower deuterium level than the pure tungsten sample. Nitrogen content in the films acts as a diffusion barrier for deuterium and leads to a higher desorption temperature, therefore to a higher binding energy.

  7. Difficulties in obtaining representative samples for compliance with the Ballast Water Management Convention

    Digital Repository Service at National Institute of Oceanography (India)

    Carney, K.J.; Basurko, O.C.; Pazouki, K.; Marsham, S.; Delany, J.E.; Desai, D.V.; Anil, A.C.; Mesbahi, E.

    ). This study has shown the effect that low sampling frequency has on the accuracy of data obtained from a 1 tonne storage tank. In reality ships can carry between 100 and 100,000 tonnes of ballast water and discharge at flow rates of 100 to over 3000 m3hr-1... and uncertainty in the accuracy of data obtained from collecting only three replicate samples at three sampling points on discharge of ballast water will, in reality, be much greater than that seen in this study. Previous studies have used different...

  8. Experimental breakdown of selected anodized aluminum samples in dilute plasmas

    Science.gov (United States)

    Grier, Norman T.; Domitz, Stanley

    1992-01-01

    Anodized aluminum samples representative of Space Station Freedom structural material were tested for electrical breakdown under space plasma conditions. In space, this potential arises across the insulating anodized coating when the spacecraft structure is driven to a negative bias relative to the external plasma potential due to plasma-surface interaction phenomena. For anodized materials used in the tests, it was found that breakdown voltage varied from 100 to 2000 volts depending on the sample. The current in the arcs depended on the sample, the capacitor, and the voltage. The level of the arc currents varied from 60 to 1000 amperes. The plasma number density varied from 3 x 10 exp 6 to 10 exp 3 ions per cc. The time between arcs increased as the number density was lowered. Corona testing of anodized samples revealed that samples with higher corona inception voltage had higher arcing inception voltages. From this it is concluded that corona testing may provide a method of screening the samples.

  9. Metabolomic Quality Assessment of EDTA Plasma and Serum Samples.

    Science.gov (United States)

    Malm, Linus; Tybring, Gunnel; Moritz, Thomas; Landin, Britta; Galli, Joakim

    2016-10-01

    Handling and processing of blood can significantly alter the molecular composition and consistency of biobank samples and can have a major impact on the identification of biomarkers. It is thus crucial to identify tools to determine the quality of samples to be used in biomarker discovery studies. In this study, a non-targeted gas chromatography/time-of-flight mass spectrometry (GC-TOFMS) metabolomic strategy was used with the aim of identifying quality markers for serum and plasma biobank collections lacking proper documentation of preanalytical handling. The effect of postcentrifugation delay was examined in serum stored in tubes with gel separation plugs and ethylenediaminetetraacetic acid (EDTA) plasma in tubes with or without gel separation plugs. The change in metabolic pattern was negligible in all sample types processed within 3 hours after centrifugation regardless of whether the samples were kept at 4°C or 22°C. After 8 and 24 hours postcentrifugation delay before aliquoting, there was a pronounced increase in the number of affected metabolites, as well as in the magnitude of the observed changes. No protective effect on the metabolites was observed in gel-separated EDTA plasma samples. In a separate series of experiments, lactate and glucose levels were determined in plasma to estimate the effect of precentrifugation delay. This separate experiment indicates that the lactate to glucose ratio may serve as a marker to identify samples with delayed time to centrifugation. Although our data from the untargeted GC-TOFMS analysis did not identify any specific markers, we conclude that plasma and serum metabolic profiles remain quite stable when plasma and serum are centrifuged and separated from the blood cells within 3 hours.

  10. A laser-induced fluorescence measurement technique for obtaining neutral hydrogen densities in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yao, X.Z.; Yang, T.F.; Chang-Diaz, F.R. [Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    1995-09-01

    The resonance fluorescence of neutral hydrogen illuminated by {ital H}{sub {alpha}} radiation has been used as a technique for the spatially and temporally resolved density measurements of neutral hydrogen in high temperature plasmas, such as in the tokamak and magnetic mirror plasma fusion devices. The fluorescence signal, usually very weak and buried in the background of stray laser light and {ital H}{sub {alpha}} emission, is very difficult to extract and its measurements are inaccurate. This paper discusses the improvement of the signal extraction using two optical path laser-induced fluorescence (LIF) methods. One optical path carries the fluorescence signal and the background (the stray laser light and {ital H}{sub {alpha}} emission), whereas the other path carries only the background signal. By combining these two signals, a clean fluorescence signal can be isolated by subtracting out the background using a differential amplifier. The measurement is obtained instantaneously from these two signals which are taken simultaneously in one pulse rather than being extracted from two separate spectra taken in two sequential pulses (double pulses). This method, therefore, makes a significant improvement on the double pulse technique in terms of the accuracy of the measurement and the time resolution. Using this LIF technique the measurement of the neutral density profile in the exhaust of a tandem mirror plasma propulsion device is obtained and presented. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  11. Highly effective sorbents obtained by treating agrowaste products in cold plasma

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Sorbents are widely used in purification of various liquids and gases, offering a universal means for wastewater and air cleaning. The most promising sorbents are those obtained from agrowaste products such as rice or buckwheat husk. Processing of husk in cold plasma modifies the composition, structure and surface properties of the raw material and raises its porosity, thus substantially improving the sorption properties of the final product.Husk as a raw material for producing sorbents has the following advantageous properties: (1) appropriate chemical composition; (2) low cost; (3) high dispersity, due to which there is no need in any special treatment of the material prior to its exposing to plasma; (4) scaly structure and developed porous surface ensuring a high surface-to-volume ratio. The best properties are displayed by the sorbents obtained in cold plasma under reduced pressures of 53.2 Pa. The raw naterial traverses the region occupied by the plasma and, as it does so, it gets heated up to a temperature of 250 - 350 ℃. The whole process involves two stages: combustion of the raw material and modification of its properties under the action of the plasma. The combustion proceeds due to the oxygen contained in the starting material. During the combustion, the hydrogen contained in the starting material and some part of the carbon also burn out.The resultant scaly sorbent is accumulated in a cooler. The scales are black; they range in sizes from 1mm to 5 mm.The sorbents obtained are remarkable for their useful properties and outperform most of the traditional sorbents used in modern industry. The starting materials are inexpensive, and their resources are almost unlimited. The sorbents have rather a low production cost (1.8-2.5($)/kg). The sorbents can be used for cleaning hydrosphere from water pollutants on a large scale. The degree of cleaning water surface from oil products with sorbents was a subject of investigation. The highest degree of purification

  12. Study of the wear resistance of ion-plasma coatings based on titanium and aluminum and obtained by magnetron sputtering

    Science.gov (United States)

    Kachalin, G. V.; Mednikov, A. F.; Tkhabisimov, A. B.; Sidorov, S. V.

    2017-05-01

    The paper presents the results of metallographic researches and erosion tests of ion-plasma coatings (based on titanium, aluminum and their nitrides), which were formed on samples of 12Kh13 and EI961 blade steels. Erosion tests and studies of characteristics of obtained by magnetron sputtering coatings were carried out by using a set of research equipment UNU “Erosion-M” NRU “MPEI”. It was found that the formed Ti/Al-TiN/AlN coatings increase the duration of blade steels erosion wear incubation period by at least in 1.5 times and have a layered structure with thicknesses of nitride layers 1.3-1.6 μm and intermediate metallic layers 0.3-0.5 μm, with a total thickness of coatings of 10-14 μm for 12Kh13steel samples and 19-21 μm for EI961 steel samples.

  13. Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

    Science.gov (United States)

    Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

    2016-01-01

    In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

  14. Microstructure and Thermoelectric Properties of Bulk Cobalt Antimonide (CoSb3) Skutterudites Obtained by Pulse Plasma Sintering

    Science.gov (United States)

    Kruszewski, M. J.; Zybała, R.; Ciupiński, Ł.; Chmielewski, M.; Adamczyk-Cieślak, B.; Michalski, A.; Rajska, M.; Kurzydłowski, K. J.

    2016-03-01

    The use of the pulse plasma sintering technique for CoSb3 thermoelectric material consolidation is reported in this work. The influence of sintering temperature on the microstructure and material properties such as the Seebeck coefficient, electrical resistivity, and thermal conductivity has been investigated. It is shown that, for samples fabricated at 923 K and 973 K, there were no significant differences in the average grain size or final phase composition. In both cases, a fine-grained polycrystalline structure of the compacts with density nearly equal to the theoretical value was achieved. Both samples were composed almost uniquely of CoSb3 phase. The measured thermoelectric parameters such as the Seebeck coefficient, electrical, and thermal conductivity showed similar dependence on temperature. For both samples, the Seebeck coefficient was negative at room temperature and showed a transition from n- to p-type conduction over the temperature range of 400 K to 460 K. The measured minimum thermal conductivity values, 4 W m-1 K-1 to 5 W m-1 K-1 at 723 K, are typical for undoped bulk CoSb3. A maximum ZT value of 0.08 at 623 K was obtained for the sample consolidated at 923 K for 5 min. The results of this work are very promising from the point of view of use of pulse plasma sintering as an alternative method for fabrication of a broad range of thermoelectric materials in the future.

  15. Effect of histologic processing on dimensions of skin samples obtained from cat cadavers.

    Science.gov (United States)

    Jeyakumar, Sakthila; Smith, Annette N; Schleis, Stephanie E; Cattley, Russell C; Tillson, D Michael; Henderson, Ralph A

    2015-11-01

    OBJECTIVE To determine changes in dimensions of feline skin samples as a result of histologic processing and to identify factors that contributed to changes in dimensions of skin samples after sample collection. SAMPLE Cadavers of 12 clinically normal cats. PROCEDURES Skin samples were obtained bilaterally from 3 locations (neck, thorax, and tibia) of each cadaver; half of the thoracic samples included underlying muscle. Length, width, and depth were measured at 5 time points (before excision, after excision, after application of ink to mark tissue margins, after fixation in neutral-buffered 10% formalin for 36 hours, and after completion of histologic processing and staining with H&E stain). Measurements obtained after sample collection were compared with measurements obtained before excision. RESULTS At the final time point, tissue samples had decreased in length (mean decrease, 32.40%) and width (mean decrease, 34.21%) and increased in depth (mean increase, 54.95%). Tissue from the tibia had the most shrinkage in length and width and that from the neck had the least shrinkage. Inclusion of underlying muscle on thoracic skin samples did not affect the degree of change in dimensions. CONCLUSIONS AND CLINICAL RELEVANCE In this study, each step during processing from excision to formalin fixation and histologic processing induced changes in tissue dimensions, which were manifested principally as shrinkage in length and width and increase in depth. Most of the changes occured during histologic processing. Inclusion of muscle did not affect thoracic skin shrinkage. Shrinkage should be a consideration when interpreting surgical margins in clinical cases. 945).

  16. Observation of microstructure of silty sand obtained from gelpush sampler and reconstituted sample

    Science.gov (United States)

    Yusa, Muhamad; Bowman, E. T.; Cubrinovski, Misko

    2017-06-01

    Observation of microstructure study of natural sand i.e. clean sand with fines (particles adjudged to be smaller than 75μm) content < 5% (Gel Push A) and silty sand with 35% fine content (Gel Push B) obtained by gel-push sampling was described. In addition, some observations from reconstituted samples prepared by dry pluviation and moist tamping were presented. Microstructures were investigated statistically by measuring particle orientation. It was evidence that natural sand (either gel push A and B) have a preferred orientation i.e. horizontally oriented. Similar particle orientation trend were observed by dry pluviated sample. Undisturbed and dry pluviated samples shows that they are anisotropic in terms of particles orientation. Moist tamped sample on the other hand, results in fairly random orientation with a slight bias towards vertical, thus does not replicate natural sand fabric.

  17. Obtaining self-samples to diagnose curable sexually transmitted infections: a systematic review of patients' experiences.

    Directory of Open Access Journals (Sweden)

    Priyamvada Paudyal

    Full Text Available Routine screening is key to sexually transmitted infection (STI prevention and control. Previous studies suggest that clinic-based screening programmes capture only a small proportion of people with STIs. Self-sampling using non- or minimally invasive techniques may be beneficial for those reluctant to actively engage with conventional sampling methods. We systematically reviewed studies of patients' experiences of obtaining self-samples to diagnose curable STIs.We conducted an electronic search of MEDLINE, EMBASE, CINAHL, PsychINFO, BNI, and Cochrane Database of Systematic Reviews to identify relevant articles published in English between January 1980 and March 2014. Studies were included if participants self-sampled for the diagnosis of a curable STI and had specifically sought participants' opinions of their experience, acceptability, preferences, or willingness to self-sample.The initial search yielded 558 references. Of these, 45 studies met the inclusion criteria. Thirty-six studies assessed patients' acceptability and experiences of self-sampling. Pooled results from these studies shows that self-sampling is a highly acceptable method with 85% of patients reporting the method to be well received and acceptable. Twenty-eight studies reported on ease of self-sampling; the majority of patients (88% in these studies found self-sampling an "easy" procedure. Self-sampling was favoured compared to clinician sampling, and home sampling was preferred to clinic-based sampling. Females and older participants were more accepting of self-sampling. Only a small minority of participants (13% reported pain during self-sampling. Participants were willing to undergo self-sampling and recommend others. Privacy and safety were the most common concerns.Self-sampling for diagnostic testing is well accepted with the majority having a positive experience and willingness to use again. Standardization of self-sampling procedures and rigorous validation of outcome

  18. 7 CFR 31.400 - Samples for wool and wool top grades; method of obtaining.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Samples for wool and wool top grades; method of obtaining. 31.400 Section 31.400 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER...

  19. The unstimulated pancreatic secretion obtained by endoscopic cannulation, and the plasma secretin levels in man.

    Science.gov (United States)

    Osnes, M; Hanssen, L E; Larsen, S

    1979-01-01

    The technique of collecting juice from the main pancreatic duct by siphonage is described. The juice was collected in 5-min fractions under basal conditions for 20 min (32 subjects) and extended to 60 min (6 subjects). Flow rate and bicarbonate concentration were significantly higher during the first collected samples, whereas concentrations of amylase and protein rose during the first 20 min of the study. All variables remained nearly constant after this period. Immunoreactive secretin (IRS) in peripheral plasma was significantly higher immediately after cannulation of the main pancreatic duct, as compared to the pre-endoscopic level. When the catheter was left in the duct and pancreatic juice drained, the IRS stabilized at a level not significantly different from the pre-endoscopic level. Positive correlations were found between flow rate and plasma level of IRS and between flow rate and bicarbonate concentrations. A negative correlation was found between the flow rate and concentrations of amylase and protein. The higher flow rate, plasma level of IRS, and bicarbonate concentration at the beginning of the examination may be due to the presence of acid and/or bile in the duodenal contents shortly after the endoscope enters the duodenum. Later in the procedure the levels have stabilized, which indicates that little or no acid or bile is passing into the duodenum. It is also concluded that secretin may be one factor responsible for the basal pancreatic secretion in man.

  20. 51Cr-EDTA plasma clearance in severe renal failure determined by one plasma sample

    DEFF Research Database (Denmark)

    Kamper, A L; Nielsen, S L

    1989-01-01

    at zero-time was derived from injected dose and body surface area. This method might provide values 1.5 ml/min below or 0.8 ml/min above the established method of 51Cr-EDTA plasma clearance, which would be acceptable for clinical purposes. It is concluded that exact plasma clearance of 51Cr-EDTA in severe......Two hundred and thirty-four measurements of standard 51Cr-EDTA plasma clearance were made in 50 patients with severe chronic renal failure. Based on these data two calculation methods were attempted using one plasma sample drawn 24 h after injection of 51Cr-EDTA. One of the methods used the 'one...... sample clearance' formulas disregarding exact time of plasma sampling. This method might provide values 3.1 ml/min below or 2.9 ml/min above the established method of total 51Cr-EDTA plasma clearance, and would thus provide insufficient agreement. In the other method an estimate of plasma activity...

  1. The influence of heating rate on superconducting characteristics of MgB{sub 2} obtained by spark plasma sintering technique

    Energy Technology Data Exchange (ETDEWEB)

    Aldica, G. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Burdusel, M. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Faculty of Materials Science and Engineering, University ’Politehnica’ of Bucharest, Splaiul Independentei 313, 060042 Bucharest (Romania); Popa, S.; Enculescu, M.; Pasuk, I. [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania); Badica, P., E-mail: badica2003@yahoo.com [National Institute of Materials Physics, Atomistilor 105bis, 077125 Magurele (Romania)

    2015-12-15

    Highlights: • MgB{sub 2} was obtained by ex-situ spark plasma sintering for different heating rates. • Heating rates were 20–475 °C/min: the optimum heating rate is ∼100 °C/min. • For 100 °C/min, J{sub c0}, H{sub irr} and (J{sub c0} x μ{sub 0}H{sub irr}) have maximum values. • For 100 °C/min, macro flux jumps are partially suppressed at 5 K. • Grain boundaries are modified depending on the heating rate. - Abstract: Superconducting bulks of MgB{sub 2} were obtained by the Spark Plasma Sintering (SPS) technique. Different heating rates of 20, 100, 235, 355, and 475 °C/min were used. Samples have high density, above 95%. The onset critical temperature T{sub c}, is about 38.8 K. There is an optimum heating rate of ∼100 °C/min to maximize the critical current density J{sub c0}, the irreversibility field H{sub irr}, the product (J{sub c0} x μ{sub 0}H{sub irr}), and to partially avoid formation of undesirable flux jumps at low temperatures. Significant microstructure differences were revealed for samples processed with low and high heating rates in respect to grain boundaries.

  2. Efficient discrimination and removal of phospholipids during electromembrane extraction from human plasma samples

    DEFF Research Database (Denmark)

    Vårdal, Linda; Gjelstad, Astrid; Huang, Chuixiu

    2017-01-01

    AIM: For the first time, extracts obtained from human plasma samples by electromembrane extraction (EME) were investigated comprehensively with particular respect to phospholipids using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Thhe purpose was to invest...

  3. Methods to obtain platelet-rich plasma and osteoinductive therapeutic use

    Directory of Open Access Journals (Sweden)

    Raquel Moreno

    2015-01-01

    Full Text Available Introduction: Platelet-Rich Plasma (PRP is autologous plasma with higher concentration of platelet than basal level, because of an extracting and concentration process. PRP therapeutical use, as osteinductor role, is a controversial issue, due to there are no clinical studies with rigorous design and no firm conclusions can be drawn regarding its uses. Propose: To provide information about methods to obtain PRP, legal considerations about its extraction and use, molecular mechanism of action, as well as available evidence about security and tolerance. Results: PRP can be obtained by manual procedures (opened technique or disposable kits (closed technique, the latter being medical devices classified as type IIa. AEMPS considers PRP as a drug, establishing some minimum requirements to guarantee safety, traceability, pharmacovigilance and information. PRP provides ideal qualities to play a powerful osteoinductor role to speed up fracture healing or to produce an efficiently and quickly osseointegration of different bone implants, due to the high growth factors content. Infiltration tolerance is generally good, however, it has to be taken into account its great angiogenical potential. Conclusions: In view of its production and application characteristics, PRP is considered as a drug on restricted medical prescription by the AEMPS, so pharmacy department must, at least, supervise its management and handling

  4. Brightness temperature - obtaining the physical properties of a non-equipartition plasma

    Science.gov (United States)

    Nokhrina, E. E.

    2017-06-01

    The limit on the intrinsic brightness temperature, attributed to `Compton catastrophe', has been established being 1012 K. Somewhat lower limit of the order of 1011.5 K is implied if we assume that the radiating plasma is in equipartition with the magnetic field - the idea that explained why the observed cores of active galactic nuclei (AGNs) sustained the limit lower than the `Compton catastrophe'. Recent observations with unprecedented high resolution by the RadioAstron have revealed systematic exceed in the observed brightness temperature. We propose means of estimating the degree of the non-equipartition regime in AGN cores. Coupled with the core-shift measurements, the method allows us to independently estimate the magnetic field strength and the particle number density at the core. We show that the ratio of magnetic energy to radiating plasma energy is of the order of 10-5, which means the flow in the core is dominated by the particle energy. We show that the magnetic field obtained by the brightness temperature measurements may be underestimated. We propose for the relativistic jets with small viewing angles the non-uniform magnetohydrodynamic model and obtain the expression for the magnetic field amplitude about two orders higher than that for the uniform model. These magnetic field amplitudes are consistent with the limiting magnetic field suggested by the `magnetically arrested disc' model.

  5. Influences of the microstructure on the wear resistance of cobalt-based ahoy coatings obtained by plasma transferred arc process

    Institute of Scientific and Technical Information of China (English)

    HOU Qingyu; GAO Jiasheng

    2005-01-01

    The microstructure, substructure, and wear characteristic of cobalt-based alloy coatings obtained by plasma transferred arc (PTA) process were investigated using optical metallurgical microscope, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and dry sand abrasion tester (DSAT). The aging effect on the structure and wear resistance of the cobalt-based PTA coating was also studied. The results show that the as-welded coating consists of cobalt-based solid solution with face-centered cubic structure and hexagonal (Cr, Fe)7C3. There are a lot of stacking faults existing in the cobalt-based solid solution. After aging at 600℃ for 60 h, the microstructure becomes coarse, and another carbide (Cr, Fe)23C6 precipitates. As a result, the wear mass loss of the aged sample is higher than that of the as-welded sample.

  6. Characterization of biochar and bio-oil samples obtained from carbonization of various biomass materials

    Energy Technology Data Exchange (ETDEWEB)

    Oezcimen, Didem; Ersoy-Mericboyu, Ayseguel [Istanbul Technical University, Chemical-Metallurgical Engineering Faculty, Department of Chemical Engineering, Maslak 34469, Istanbul (Turkey)

    2010-06-15

    Apricot stone, hazelnut shell, grapeseed and chestnut shell are important biomass residues obtained from the food processing industry in Turkey and they have a great importance as being a source of energy. In this study, the characteristics of bio-oil and biochar samples obtained from the carbonization of apricot stone, hazelnut shell, grapeseed and chestnut shell were investigated. It was found that the biochar products can be characterized as carbon rich, high heating value and relatively pollution-free potential solid biofuels. The bio-oil products were also presented as environmentally friendly green biofuel candidates. (author)

  7. Sensitivity of the DRP-4DVar Performance to Perturbation Samples Obtained by Two Different Methods

    Institute of Scientific and Technical Information of China (English)

    ZHAO Juan; WANG Bin

    2010-01-01

    The dimension-reduced projection four-dimensional variational data assimilation (DRP-4DVar) approach utilizes the ensemble of historical forecasts to estimate the background error covariance (BEC) and directly obtains the analysis in the ensemble space. As a result, the quality of ensemble members significantly affects the DRP-4DVar performance. The historical-forecast-based initial perturbation samples are flow-dependent and can describe the error-growth pattern of the atmospheric model and the balanced relationship between different model variables. However, the ensemble spread is not big enough because of the short time interval between adjacent historical samples and the limited ensemble size. In this study, the BEC of the Weather Research and Forecasting Model (WRF) three-dimensional variational data assimilation (3DVar) system is employed to produce initial perturbation samples for the DRP-4DVar. The control variable perturbation method based on the structure characteristics of the 3DVar BEC produces initial perturbation samples that have reasonable background error correlations. Moreover, the estimated BEC also has good dynamic and physical consistency between variables after the initial perturbation samples undergo a development with a 6- or 12-h model forward integration. In terms of computational expense, the historical forecast results can be obtained without any additional computational cost at the operational numerical weather forecast centers, while the integration of samples from the 3DVar-based control variable perturbation method is time-consuming, but this difficulty can be alleviated through parallel computing. Although the assimilation run with the historical-forecast-based ensemble generates slightly better initial analysis field, the forecasts from the assimilation experiment using the 3DVar method performs better during the period from 12 to 30 h. Moreover, precipitation is simulated significantly better when the new ensemble is used. In

  8. Multiplex PCR-based detection of Leptospira in environmental water samples obtained from a slum settlement

    Directory of Open Access Journals (Sweden)

    Juliana Magalhães Vital-Brazil

    2010-05-01

    Full Text Available The aim of this study was to apply a molecular protocol to detect leptospiral DNA in environmental water samples. The study was carried out in a peri-urban settlement in Petrópolis, state of Rio de Janeiro. A multiplex PCR method employing the primers LipL32 and 16SrRNA was used. Three out of 100 analysed samples were positive in the multiplex PCR, two were considered to have saprophytic leptospires and one had pathogenic leptospires. The results obtained supported the idea that multiplex PCR can be used to detect Leptospira spp in water samples. This method was also able to differentiate between saprophytic and pathogenic leptospires and was able to do so much more easily than conventional methodologies.

  9. Three Kinds of Films Obtained from Plasma Poly merization of Octamethylcyclotetrasioxane

    Institute of Scientific and Technical Information of China (English)

    刘益民; 张广秋; 葛袁静

    2002-01-01

    Three kinds of "films" i.e. cross-linked film, grainy film and transparent film, were obtained in the process of plasma polymerization of Octamethylcyclotetrasioxane(D4) under different conditions. From SEM photos, we can see that the cross-linked film has a network form.From XPS spectra, we can see that the content of Si-C bond of the cross-linked film is lower than t hat of the transparent film, and this result agrees well with the test results of FTIR spectra. This proves that the cleavage of the Si-C bond and C-H bond are the main cleavage in the formation of cross-linked film, whereas the cleavage of the Si-O is the main cleavage in the formation of transparent film. In order to enhance the collision of the reactive particles and investigate the influence of magnetic field on the plasma polymerization, we introduced the magnetic field, as a result, we got the grainy film.

  10. Characterization of Microstructure and Thermal Properties of YSZ Coatings Obtained by Axial Suspension Plasma Spraying (ASPS)

    Science.gov (United States)

    Ganvir, Ashish; Curry, Nicholas; Björklund, Stefan; Markocsan, Nicolaie; Nylén, Per

    2015-10-01

    The paper aims at demonstrating various microstructures which can be obtained using the suspension spraying technique and their respective significance in enhancing the thermal insulation property of a thermal barrier coating. Three different types of coating microstructures are discussed which were produced by the Axial Suspension Plasma Spraying. Detailed characterization of coatings was then performed. Optical and scanning electron microscopy were utilized for microstructure evaluations; x-ray diffraction for phase analysis; water impregnation, image analysis, and mercury intrusion porosimetry for porosity analysis, and laser flash analysis for thermal diffusivity measurements were used. The results showed that Axial Suspension Plasma Spraying can generate vertically cracked, porous, and feathery columnar-type microstructures. Pore size distribution was found in micron, submicron, and nanometer range. Higher overall porosity, the lower density of vertical cracks or inter-column spacing, and higher inter-pass porosity favored thermal insulation property of the coating. Significant increase in thermal diffusivity and conductivity was found at higher temperature, which is believed to be due to the pore rearrangement (sintering and pore coarsening). Thermal conductivity values for these coatings were also compared with electron beam physical vapor deposition (EBPVD) thermal barrier coatings from the literature and found to be much lower.

  11. Reproducibility of Circulating MicroRNAs in Stored Plasma Samples.

    Directory of Open Access Journals (Sweden)

    Monica L Bertoia

    Full Text Available Most studies of microRNA (miRNA and disease have examined tissue-specific expression in limited numbers of samples. The presence of circulating miRNAs in plasma samples provides the opportunity to examine prospective associations between miRNA expression and disease in initially healthy individuals. However, little data exist on the reproducibility of miRNAs in stored plasma.We used Real-Time PCR to measure 61 pre-selected microRNA candidates in stored plasma. Coefficients of variation (CVs were used to assess inter-assay reliability (n = 15 and within-person stability over one year (n = 80. Intraclass correlation coefficients (ICCs and polychoric correlation coefficients were used to assess within-person stability and delayed processing reproducibility (whole blood stored at 4°C for 0, 24 and 48 hours; n = 12 samples.Of 61 selected miRNAs, 23 were detected in at least 50% of samples and had average CVs below 20% for inter-assay reproducibility and 31 for delayed processing reproducibility. Ten miRNAs were detected in at least 50% of samples, had average CVs below 20% and had ICCs above 0.4 for within-person stability over 1-2 years, six of which satisfied criteria for both interassay reproducibility and short-term within-person stability (miR-17-5p, -191-5p, -26a-5p, -27b-3p, -320a, and -375 and two all three types of reproducibility (miR-27b-3p and -26a-5p. However, many miRNAs with acceptable average CVs had high maximum CVs, most had low expression levels, and several had low ICCs with delayed processing.About a tenth of miRNAs plausibly related to chronic disease were reliably detected in stored samples of healthy adults.

  12. Transparent Yttrium Aluminium Garnet Obtained by Spark Plasma Sintering of Lyophilized Gels

    Directory of Open Access Journals (Sweden)

    M. Suárez

    2009-01-01

    Full Text Available Lyophilized YAG gel, synthesized by the coprecipitation technique, has been sintered to transparency by spark plasma sintering method at 1500∘C. Whereas conventionally dried gels show large agglomerates, over 1 μm, powders from lyophilized gels show no agglomeration with an average particle size below 100 nm. The absence of agglomerates affects on the optical properties of the sintered materials: conventionally dried powders are opaque after sintering, whereas 0.8 mm thick transparent YAG materials with in-line transmittances close to 60% at 680 nm and over 80% in the infrared range have been obtained for the lyophilized gels.

  13. Use of thin films obtained by plasma polymerization for grain protection and germination enhancement

    Directory of Open Access Journals (Sweden)

    Rodrigo A. M. Carvalho

    2005-12-01

    Full Text Available In this work, preliminary results of the use of hydrophobic thin films obtained by plasma deposition to protect grains and seeds are presented: grains coated by the films did not present biological degradation when stored in a saturated water vapor environment, but had their germination accelerated in the presence of water. A model that explains the difference of behavior of the films when exposed to water in vapor form or in liquid form, based on the formation of microchannels within the film that lead to water uptake in seeds, is presented. The model was successfully tested using quartz crystal measurements, which showed that the microchannels within the films can favor the adsorption and permeation of water when the films are immersed in water.

  14. Analysis of cytokine profile and growth factors in platelet-rich plasma obtained by open systems and commercial columns.

    Science.gov (United States)

    Pochini, Alberto de Castro; Antonioli, Eliane; Bucci, Daniella Zanetti; Sardinha, Luiz Roberto; Andreoli, Carlos Vicente; Ferretti, Mario; Ejnisman, Benno; Goldberg, Anna Carla; Cohen, Moisés

    2016-01-01

    To evaluate growth factors and cytokines in samples of platelet-rich plasma obtained by three different centrifugation methods. Peripheral blood of six individuals with no hematological diseases, aged 18 to 68 years, was drawn to obtain platelet-rich plasma, using the open method and commercial columns by Medtronic and Biomet. The products obtained with the different types of centrifugation were submitted to laboratory analysis, including pro-inflammatory cytokines and chemokines by flow cytometry assays, the concentration of fibroblast growth factors-2 (FGF-2) and transforming growth factor-beta1 (TGF-β1). The diverse separation methods generated systematically different profiles regarding number of platelets and leukocytes. The Medtronic system yielded a product with the highest concentration of platelets, and the open method, with the lowest concentration of platelets. The results of cytokine analysis showed that the different types of centrifugation yielded products with high concentrations of interleukin 8, interleukin 1β. The open system resulted in a product with high levels of interleukin 6. Other cytokines and chemokines measured were similar between systems. The product obtained with the open method showed higher levels of TGF-β1 in relation to other systems and low FGF-2 levels. The formed elements, growth factors and cytokines in samples of platelet-rich plasma varied according to the centrifugation technique used. Avaliar fatores de crescimento e citocinas em amostras de plasma rico em plaquetas obtidas por três diferentes métodos de centrifugação. Foi coletado sangue periférico de seis indivíduos, sem doença hematológica, com idades entre 18 e 68 anos, para obtenção de plasma rico em plaquetas, utilizando o método aberto e sistemas comerciais das empresas Medtronic e Biomet. Os produtos obtidos com os diferentes tipos de centrifugação foram submetidos às análises laboratoriais, incluindo citocinas próinflamatórias e quimiocinas

  15. Effects of anesthesia and blood sampling techniques on plasma metabolites and corticosterone in the rat.

    Science.gov (United States)

    Arnold, Myrtha; Langhans, Wolfgang

    2010-04-19

    Blood is routinely sampled from laboratory animals in biomedical research, and many of the commonly applied sampling techniques require anesthesia. Acute effects of many sampling and anesthesia procedures may confound the results, but those effects are incompletely characterized. We here compare the effects of four common anesthesia procedures (inhalation anesthesia with ether (EA) or isoflurane (IA) and intraperitoneal injection anesthesia with xylazin/ketamine (XKA) or medetomidine/midazolam/fentanyl (MMFA)) on plasma concentrations of glucose, lactate, non-esterified fatty acids (NEFAs), and corticosterone in blood obtained from a previously implanted jugular vein (JV) catheter with the effect of JV blood sampling from non-anesthetized, freely-moving rats (JV-NA). Also, we included in the comparison two other blood sampling procedures usually performed without anesthesia (NA), i.e., puncture of the saphenic vein (SV) and tail incision (TI). Whereas the control procedure (JV-NA) did not significantly affect any of the target parameters, plasma glucose increased from 14 (JV-IA) to 44 (JV-MMFA) % (all Ps=0.05 when compared with the control procedure) in all blood samples collected in anesthesia and was 12 and 14% lower (both Pssamples, respectively. Plasma lactate increased from 74 (JV-IA) to 226% (SV-NA) (all Pssampling and anesthesia procedures except for JV-XKA and JV-MMF. Plasma NEFAs increased to 52% (P0.05). Finally, only the JV-EA and the JV-MMFA procedures increased plasma corticosterone (+525 and +353%, respectively, both Pssampling procedures can have profound acute effects on plasma metabolite and hormone concentrations. This must be considered for the design and interpretation of blood sampling experiments in laboratory animals. (c) 2010. Published by Elsevier Inc.

  16. Optimization of mechanical alloying and spark-plasma sintering regimes to obtain ferrite–martensitic ODS steel

    Directory of Open Access Journals (Sweden)

    M.S. Staltsov

    2016-12-01

    Full Text Available The results of structure investigation, distribution uniformity of dispersed particles of Y2O3, porosity and density of the ferritic/martensitic reactor steel EP-450 (0.12C–13Cr–2Mo–Nb–V–B, wt% produced by spark-plasma sintering (SPS are presented. More than 140 samples were produced using different combinations of mechanical alloying (time, speed of attritor rotation and SPS parameters (temperature, speed of reaching preset temperature, pressure and time of exposure under pressure, concentration of strengthening particles. It is determined that the absence of strengthening Y2O3 nano-particles in local volumes of sintered specimens is connected with the imperfection of mechanical alloying, namely, the formation of agglomerates of matrix steel powder containing no oxide nano-particles. It has been determined that the time of mechanical alloying should not exceed 30h to provide minimum powder agglomeration, uniform distribution of Y2O3 particles in the powder mixture and minimum porosity of sintered samples. Spark-plasma sintering should be performed at the lowest possible temperature. As a result it was found that samples with 99% theoretical density can be obtained using the following optimized SPS-parameters: sintering temperature is 1098÷1163K; speed for reaching the preset temperature is >573K/min; load is 70÷80MPa; time of exposure under pressure – either without isothermal exposure, or exposure during ≥3min; optimum quantity of Y2O3 is 0.2÷0.5wt%.

  17. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Directory of Open Access Journals (Sweden)

    Stephen P Good

    Full Text Available Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18O, > 160‰ for δ(2H and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰ were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  18. Transcriptional profiling of degraded RNA in cryopreserved and fixed tissue samples obtained at autopsy

    Directory of Open Access Journals (Sweden)

    Alhasan Samir

    2006-12-01

    Full Text Available Abstract Background Traditional multiplexed gene expression methods require well preserved, intact RNA. Such specimens are difficult to acquire in clinical practice where formalin fixation is the standard procedure for processing tissue. Even when special handling methods are used to obtain frozen tissue, there may be RNA degradation; for example autopsy samples where degradation occurs both pre-mortem and during the interval between death and cryopreservation. Although specimens with partially degraded RNA can be analyzed by qRT-PCR, these analyses can only be done individually or at low levels of multiplexing and are laborious and expensive to run for large numbers of RNA targets. Methods We evaluated the ability of the cDNA-mediated Annealing, Selection, extension, and Ligation (DASL assay to provide highly multiplexed analyses of cryopreserved and formalin fixed, paraffin embedded (FFPE tissues obtained at autopsy. Each assay provides data on 1536 targets, and can be performed on specimens with RNA fragments as small as 60 bp. Results The DASL performed accurately and consistently with cryopreserved RNA obtained at autopsy as well as with RNA extracted from formalin-fixed paraffin embedded tissue that had a cryopreserved mirror image specimen with high quality RNA. In FFPE tissue where the cryopreserved mirror image specimen was of low quality the assay performed reproducibly on some but not all specimens. Conclusion The DASL assay provides reproducible results from cryopreserved specimens and many FFPE specimens obtained at autopsy. Gene expression analyses of these specimens may be especially valuable for the study of non-cancer endpoints, where surgical specimens are rarely available.

  19. Investigation of multifractal nature of floating potential fluctuations obtained from a dc glow discharge magnetized plasma

    Science.gov (United States)

    Shaw, Pankaj Kumar; Saha, Debajyoti; Ghosh, Sabuj; Janaki, M. S.; Iyengar, A. N. Sekar

    2017-03-01

    In this paper, multifractal detrended fluctuation analysis (MF-DFA) has been used to analyze the floating potential fluctuations obtained with a Langmuir probe from a dc glow discharge magnetized plasma device. The generalized Hurst exponents (h(q)) , local fluctuation function (Fq(s)) , the Rényi exponents (τ(q)) and the multifractal spectrum F(α) have been calculated by applying the MF-DFA method. The result of the MF-DFA shows the multifractal nature of these fluctuations. We have investigated the influence of magnetic field on the multifractal nature of the fluctuations and it is seen that degree of multifractality is reduced with the increase in the magnetic field strength. The values of h(q) have been restricted between 0.7 and 1 for the magnetized fluctuations. This result is evidence of the existence of long-range correlations in the fluctuations. Furthermore, we employed shuffle and surrogate approaches to analyze the origins of multifractality. Comparing the MF-DFA results for the data set to those for shuffled and surrogate series, we have found that its multifractal nature is due to the existence of significant long-term correlation.

  20. Simulation of motions of the plasma in a fusion reactor for obtaining of future energy

    Science.gov (United States)

    Zhumabekov, Askhat

    2017-01-01

    According to the most conservative estimates, by the middle of the XXI century in the world energy consumption will double. This will be a consequence of the global economic development, population growth and other geopolitical and economic factors. Energy consumption in the world is growing much faster than its production and industrial use of new advanced technologies in the energy sector, for objective reasons, will not begin until 2030. This paper discusses how to obtain and develop nuclear energy on the experience of the National Nuclear Center. Implemented model for the problem of plasma confinement, and also presents the main achievements of modern construction and Megaproject National Nuclear Center in Kurchatov, the Republic of Kazakhstan. Spend a social survey in the East Kazakhstan region on the theme: “Prospects for the development of nuclear energy in Kazakhstan” and the citizens’ opinion. Narration new priorities for May 22, 2015 in Ust-Kamenogorsk in the industrial park “Altai” based on the competition of innovation projects green technology in the international exhibition “OSKEMEN EXPO – 2015”, with the participation of the regional authorities of the Republic of Kazakhstan, representatives of JSC NC “Astana Expo” and delegations from Japan, Russia, Canada, USA, South Korea.

  1. Investigation of mechanical properties of thermal coatings obtained during plasma spraying of powder zirconium dioxide

    Science.gov (United States)

    Ibragimov, A. R.; Ilinkova, T. A.; Shafigullin, L. N.; Saifutdinov, A. I.

    2017-01-01

    Thermal coatings of zirconia partially stabilized with yttrium, deposited by low-temperature plasma, are the basis for the thermal protection of aircraft engine. At the same time there is an actual problem of selection of coating systems “ceramic layer - underlayer” of great thickness, providing better thermal protection, but having low strength characteristics due to the accumulation of internal stresses. To determine the optimal thickness of the test method used in the 4-point bending to allow the surface coating to explore in the elastic-plastic behavior of the field of coatings and strength. Based on the experimental results established the role of underlayer in the formation of the complex mechanical properties of thermal barrier coatings. With a well formed underlayer (PVNH16U6) system becomes sensitive to a change in thickness of the coating, to optimize the response on the strength and deformation criteria. According to the results the optimum ratio of the thickness of the ceramic layer and the underlayer should be regarded as the ratio of 3-5 for which the highest strength values were obtained for all the test coating systems.

  2. Comparison of human glomerulus proteomic profiles obtained from low quantities of samples by different mass spectrometry with the comprehensive database

    Directory of Open Access Journals (Sweden)

    Liu Zan

    2011-08-01

    Full Text Available Abstract Background We have previously constructed an in-depth human glomerulus proteome database from a large amount of sample for understanding renal disease pathogenesis and aiding the biomarker exploration. However, it is usually a challenge for clinical research to get enough tissues for large-scale proteomic characterization. Therefore, in this study, we focused on high-confidence proteomics analysis on small amounts of human glomeruli comparable to those obtained from biopsies using different mass spectrometers and compared these results to the comprehensive database. Results One microgram of human glomerular protein digest was analyzed each on five LC- combined mass spectrometers (LIT-TOF, LTQ-Orbitrap, Q-TOF, LIT and MALDI-TOF/TOF yielding 139, 185, 94, 255 and 108 proteins respectively identified with strict criteria to ensure high confidence (> 99% and low false discovery rate (FDR ( Conclusion This study showed representative human glomerulus proteomic profiles obtained from biopsies through analysis of comparable amounts of samples by different mass spectrometry. Our results implicated that high abundant proteins are more likely to be reproducibly identified in multiple mass spectrometers runs and different mass spectrometers. Furthermore, many podocyte essential proteins such as nephrin, podocin, podocalyxin and synaptopodin were also identified from the small samples in this study. Bioinformatic enrichment analysis results extended our understanding of the major glomerular proteins about their subcellular distributions and functions. The present study indicated that the proteins localized in certain cellular compartments, such as actin cytoskeleton, mitochondrial matrix, cell surface, basolateral plasma membrane, contractile fiber, proteinaceous extracellular matrix and adherens junction, represent high abundant glomerular proteins and these subcellular structures are also highly significantly over-represented in the glomerulus

  3. Nanoliter viscometer for analyzing blood plasma and other liquid samples.

    Science.gov (United States)

    Srivastava, Nimisha; Davenport, Robertson D; Burns, Mark A

    2005-01-15

    We have developed a microfabricated nanoliter capillary viscometer that quickly, easily, and inexpensively measures the viscosity of liquids. The measurement of viscosity is based on capillary pressure-driven flow inside microfluidic channels (depth approximately 30 microm and width approximately 300 microm). Accurate and precise viscosity measurements can be made in less than 100 s while using only 600 nL of liquid sample. The silicon-glass hybrid device (18 mm by 15 mm) contains on-chip components that measure the driving capillary pressure difference and the relevant geometrical parameters; these components make the nanoliter viscometer completely self-calibrating, robust, and easy to use. Several different microfabricated viscometers were tested using solutions with viscosities ranging from 1 to 5 cP, a range relevant to biological fluids (urine, blood, blood plasma, etc.). Blood plasma samples collected from patients with the symptoms of hyperviscosity syndrome were tested on the nanoliter capillary viscometer to an accuracy of 3%. Such self-calibrating nanoliter viscometers may have widespread applications in chemical, biological, and medical laboratories as well as in personal health care.

  4. Properties of the prominence magnetic field and plasma distributions as obtained from 3D whole-prominence fine structure modeling

    Science.gov (United States)

    Gunár, S.; Mackay, D. H.

    2016-07-01

    Aims: We analyze distributions of the magnetic field strength and prominence plasma (temperature, pressure, plasma β, and mass) using the 3D whole-prominence fine structure model. Methods: The model combines a 3D magnetic field configuration of an entire prominence, obtained from non-linear force-free field simulations, with a detailed semi-empirically derived description of the prominence plasma. The plasma is located in magnetic dips in hydrostatic equilibrium and is distributed along multiple fine structures within the 3D magnetic model. Results: We show that in the modeled prominence, the variations of the magnetic field strength and its orientation are insignificant on scales comparable to the smallest dimensions of the observed prominence fine structures. We also show the ability of the 3D whole-prominence fine structure model to reveal the distribution of the prominence plasma with respect to its temperature within the prominence volume. This provides new insights into the composition of the prominence-corona transition region. We further demonstrate that the values of the plasma β are small throughout the majority of the modeled prominences when realistic photospheric magnetic flux distributions and prominence plasma parameters are assumed. While this is generally true, we also find that in the region with the deepest magnetic dips, the plasma β may increase towards unity. Finally, we show that the mass of the modeled prominence plasma is in good agreement with the mass of observed non-eruptive prominences.

  5. Structure and Properties of Sio2 Nanopowder Obtained From High-Silica Raw Materials by Plasma Method

    Science.gov (United States)

    Kosmachev, P. V.; Vlasov, V. A.; Skripnikova, N. K.

    2017-06-01

    The paper presents a plasma-assisted generation of nanodisperse powder obtained from diatomite, a natural high-silica material. The structure and properties of the obtained material are investigated using the transmission electron microscopy, energy dispersive X-Ray spectroscopy, infrared and X-ray photoelectron spectroscopies, and Brunauer-Emmett-Teller method. It is clearly shown that the obtained SiO2 nanoparticles are spherical, polydisperse and represented in the form of agglomerates. The specific surface of this nanopowder is 32 m2/g. Thermodynamic modeling of the plasma-assisted process is used to obtain the equilibrium compositions of condensed and gaseous reaction products. The plasma process is performed within the 300-5000 K temperature range.

  6. Convection-Diffusion Model for Atmospheric Pressure Plasma Jets: Obtaining Off-Axis Data from On-Axis Measurements

    Science.gov (United States)

    Schmidt-Bleker, Ansgar; Dünnbier, Mario; Winter, Jörn; Weltmann, Klaus-Dieter; Reuter, Stephan

    2012-10-01

    An analytical convection-diffusion model for atmospheric pressure plasma jets is presented. The model can be applied both for ambient air species diffusion and for heat transfer into a jets effluent. Using on-axis data from experiments as input, the model can be used to extrapolate the measured quantities to the complete domain for laminar flows and near-axis region for turbulent flows. The method is applied to experimental data obtained from molecular beam mass spectrometry as well as from a VUV absorption spectrometry method using the plasma jet itself as a VUV emitter. The measurements are conducted on a turbulent atmospheric pressure argon plasma jet with a protective gas nozzle, allowing for the creation of a shielding gas curtain around the plasma jets effluent. The results obtained from the hybrid analytical-experimental method are compared to computational fluid dynamics simulations.

  7. Plasma density evolution in plasma opening switch obtained by a time-resolved sensitive He-Ne interferometer

    Science.gov (United States)

    Chen, Lin; Ren, Jing; Guo, Fan; Zhou, LiangJi; Li, Ye; He, An; Jiang, Wei

    2014-03-01

    To understand the formation process of vacuum gap in coaxial microsecond conduction time plasma opening switch (POS), we have made measurements of the line-integrated plasma density during switch operation using a time-resolved sensitive He-Ne interferometer. The conduction current and conduction time in experiments are about 120 kA and 1 μs, respectively. As a result, more than 85% of conduction current has been transferred to an inductive load with rise time of 130 ns. The radial dependence of the density is measured by changing the radial location of the line-of-sight for shots with the same nominal POS parameters. During the conduction phase, the line-integrated plasma density in POS increases at all radial locations over the gun-only case by further ionization of material injected from the guns. The current conduction is observed to cause a radial redistribution of the switch plasma. A vacuum gap forms rapidly in the plasma at 5.5 mm from the center conductor, which is consistent with the location where magnetic pressure is the largest, allowing current to be transferred from the POS to the load.

  8. Obtaining nano-sized silver particles in aqueous solution under the influence of the contact nonequilibrium low-temperature plasma

    OpenAIRE

    Сергеева, Ольга Вячеславовна; Пивоваров, Александр Андреевич

    2015-01-01

    The influence of plasma-treating aqueous solution containing silver ions for formation of the nanoparticles of silver, their size and their variation over a predetermined time interval. As a processing tool to use contact nonequilibrium low-temperature plasma is formed between the electrode (anode), located in the gas phase and the liquid surface and recessed electrode in there. The electrolytic solution AgNO3 in the distilled water used as cathode. Studied the characteristics of the obtained...

  9. Superhydrophilic poly(L-lactic acid) electrospun membranes for biomedical applications obtained by argon and oxygen plasma treatment

    Science.gov (United States)

    Correia, D. M.; Ribeiro, C.; Botelho, G.; Borges, J.; Lopes, C.; Vaz, F.; Carabineiro, S. A. C.; Machado, A. V.; Lanceros-Méndez, S.

    2016-05-01

    Poly(L-lactic acid), PLLA, electrospun membranes and films were plasma treated at different times and power with argon (Ar) and oxygen (O2), independently, in order to modify the hydrophobic nature of the PLLA membranes. Both Ar and O2 plasma treatments promote an increase in fiber average size of the electrospun membranes from 830 ± 282 nm to 866 ± 361 and 1179 ± 397 nm, respectively, for the maximum exposure time (970 s) and power (100 W). No influence of plasma treatment was detected in the physical-chemical characteristics of PLLA, such as chemical structure, polymer phase or degree of crystallinity. On the other hand, an increase in the roughness of the films was obtained both with argon and oxygen plasma treatments. Surface wettability studies revealed a decrease in the contact angle with increasing plasma treatment time for a given power and with increasing power for a given time in membranes and films and superhydrophilic electrospun fiber membranes were obtained. Results showed that the argon and oxygen plasma treatments can be used to tailor hydrophilicity of PLLA membranes for biomedical applications. MTT assay results indicated that plasma treatments under Ar and O2 do not influence the metabolic activity of MC3T3-E1 pre-osteoblast cells.

  10. Hydrophobic Coatings on Cotton Obtained by in Situ Plasma Polymerization of a Fluorinated Monomer in Ethanol Solutions.

    Science.gov (United States)

    Molina, Ricardo; Teixidó, Josep Maria; Kan, Chi-Wai; Jovančić, Petar

    2017-02-15

    Plasma polymerization using hydrophobic monomers in the gas phase is a well-known technology to generate hydrophobic coatings. However, synthesis of functional hydrophobic coatings using plasma technology in liquids has not yet been accomplished. This work is consequently focused on polymerization of a liquid fluorinated monomer on cotton fabric initiated by atmospheric plasma in a dielectric barrier discharge configuration. Functional hydrophobic coatings on cotton were successfully achieved using in situ atmospheric plasma-initiated polymerization of fluorinated monomer dissolved in ethanol. Gravimetric measurements reveal that the amount of polymer deposited on cotton substrates can be modulated with the concentration of monomer in ethanol solution, and cross-linking reactions occur during plasma polymerization of a fluorinated monomer even without the presence of a cross-linking agent. FTIR and XPS analysis were used to study the chemical composition of hydrophobic coatings and to get insights into the physicochemical processes involved in plasma treatment. SEM analysis reveals that at high monomer concentration, coatings possess a three-dimensional pattern with a characteristic interconnected porous network structure. EDX analysis reveals that plasma polymerization of fluorinated monomers takes place preferentially at the surface of cotton fabric and negligible polymerization takes place inside the cotton fabric. Wetting time measurements confirm the hydrophobicity of cotton coatings obtained although equilibrium moisture content was slightly decreased. Additionally, the abrasion behavior and resistance to washing of plasma-coated cotton has been evaluated.

  11. Photoactive TiO2 coatings obtained by Plasma Electrolytic Oxidation in refrigerated electrolytes

    Science.gov (United States)

    Franz, Silvia; Perego, Daniele; Marchese, Ottavia; Lucotti, Andrea; Bestetti, Massimiliano

    2016-11-01

    The effect of synthesis conditions on the properties of nanoporous TiO2 coatings obtained by PEO in refrigerated electrolytes have been investigated. Linear sweep voltammetry was carried out on the TiO2 coatings, in dark and under UV-C irradiation, in order to assess the photoelectrochemical behavior of samples. The largest photocurrents (0.18 mA/cm2) were measured on TiO2 coatings obtained by PEO in refrigerated aqueous solutions. UV-vis spectra revealed that lowering the processing temperature from 20 to -3.5 °C induced a blue-shift of the absorption band of the TiO2 coatings from 3.05 to 3.42 eV. The main advantage of PEO in refrigerated aqueous solutions over current approaches, based on anodic oxidation and thermal treatments, is that the synthesis of photoactive TiO2 coatings can be carried out in a relatively easy, quick and reproducible way, without annealing pre- and post-treatments. Furthermore, by controlling the solution temperature in PEO process, the photocurrent of the resulting TiO2 coating reaches quite high values.

  12. Plasma-surface modification vs air oxidation on carbon obtained from peach stone: Textural and chemical changes and the efficiency as adsorbents

    Science.gov (United States)

    De Velasco Maldonado, Paola S.; Hernández-Montoya, Virginia; Montes-Morán, Miguel A.

    2016-10-01

    Carbons were prepared from peach stones (Prunus persica) using different carbonization temperatures (600, 800 and 1000 °C). A selected sample was modified by oxidation using conventional oxidation techniques (thermal treatment in air atmosphere) and with cold oxygen plasma oxidation, under different conditions. Samples were characterized using elemental analysis, FT-IR spectroscopy, nitrogen adsorption isotherms at -196 °C, SEM/EDX analysis, potentiometric titration and XPS analysis. Carbons with and without oxidation were employed in the adsorption of Pb2+ in aqueous solution. Results obtained indicated that the materials with high contents of acidic oxygen groups were more efficient in the removal of Pb2+, values as high as approx. 40 mg g-1 being obtained for the best performing carbon. Textural properties of the original, un-oxidized carbon were significantly altered only after oxidation under air atmosphere at 450 °C. On the other hand, the samples oxidized with plasma show little changes in the textural parameters and a slight increase in the specific surface was observed for the sample treated at high RF power (100 W). Additionally, a significant increment of the oxygen content was observed for the plasma oxidized samples, as measured by XPS.

  13. Molecular Identification of Leishmania Species Using Samples Obtained from Negative Stained Smears

    Directory of Open Access Journals (Sweden)

    MA Mohaghegh

    2013-06-01

    Full Text Available Background: Cutaneous Leishmaniasis (CL is a parasitic skin disease. Diagnosis primarily is based on clinical signs and microscopic observation of parasite on direct stained smears or tissue sections. Sensitivity of direct smear is not as high as molecular methods. The aim of this study was to identify and characterize Leishmania species among the negative direct smears obtained from skin ulcers sus­pected to CL by PCR method.Methods: Among 81 patients with suspicious skin lesions to CL referred to the Parasitology lab, nega­tive Giemsa stained smears were collected. DNA extraction performed by scraping stained smears, then PCR was performed.Results: Among the DNA extracted from smears, L. tropica was isolated from 9 (11.1% of the smears and L.major was not isolated from any samples.Conclusion: Direct microscopy on stained smears for diagnosis of leishmaniasis is not enough accu­rate. PCR is recommended for clinically suspected lesions with negative result of direct smear.

  14. Long-term performance and stability of molecular shotgun lipidomic analysis of human plasma samples.

    Science.gov (United States)

    Heiskanen, Laura A; Suoniemi, Matti; Ta, Hung Xuan; Tarasov, Kirill; Ekroos, Kim

    2013-09-17

    The stability of the lipid concentration levels in shotgun lipidomics analysis was tracked over a period of 3.5 years. Concentration levels in several lipid classes, such as phospholipids, were determined in human plasma lipid extracts. Impact of the following factors on the analysis was investigated: sample amount, internal standard amount, and sample dilution factor. Moreover, the reproducibility of lipid profiles obtained in both polarity modes was evaluated. Total number of samples analyzed was approximately 6800 and 7300 samples in negative and positive ion modes, respectively, out of which 610 and 639 instrument control samples were used in stability calculations. The assessed shotgun lipidomics approach showed to be remarkably robust and reproducible, requiring no batch corrections. Coefficients of variation (CVs) of lipid mean concentration measured with optimized analytical parameters were typically less than 15%. The high reproducibility indicated that no lipid degradation occurred during the monitored time period.

  15. Switchable hydrophobic/hydrophilic surface of electrospun poly (L-lactide) membranes obtained by CF4 microwave plasma treatment

    Science.gov (United States)

    Yue, Mengyao; Zhou, Baoming; Jiao, Kunyan; Qian, Xiaoming; Xu, Zhiwei; Teng, Kunyue; Zhao, Lihuan; Wang, Jiajun; Jiao, Yanan

    2015-02-01

    A switchable surface that promotes either hydrophobic or hydrophilic wettability of poly (L-lactide) (PLLA) microfibrous membranes is obtained by CF4 microwave plasma treatment in this paper. The results indicated that both etching and grafting process occurred during the CF4 plasma treatment and these two factors synergistically affected the final surface wettability of PLLA membranes. When plasma treatment was taken under a relatively low power, the surface wettability of PLLA membranes turned from hydrophobic to hydrophilic. Especially when CF4 plasma treatment was taken under 100 W for 10 min and 150 W for 5 min, the water contact angle sharply decreased from 116 ± 3.0° to ∼0°. According to Field-emission scanning electron microscopy (FESEM) results, the PLLA fibers were notably etched by CF4 plasma treatment. Combined with the X-ray photoelectron spectroscopy (XPS) measurements, only a few fluorine-containing groups were grafted onto the surface, so the etching effect directly affected the surface wettability of PLLA membranes in low plasma power condition. However, with the plasma power increasing to 200 W, the PLLA membrane surface turned to hydrophobic again. In contrast, the morphology changes of PLLA fiber surfaces were not obvious while a large number of fluorine-containing groups grafted onto the surface. So the grafting effect gradually became the major factor for the final surface wettability.

  16. Some new insights of the characteristics of equatorial plasma bubbles obtained from Indian region

    Science.gov (United States)

    Narayanan, V. L.; Gurubaran, S.; Shiny, M. B. Berlin; Emperumal, K.; Patil, P. T.

    2017-04-01

    All-sky imaging observations of OI 630.0 nm airglow were carried out in campaign mode from Panhala (16.8°N, 74.1°E geographic; 11.1°N dip latitude), India, during January to March 2008. On 14 of 37 nights, equatorial plasma bubbles were observed. The drift speeds were observed to decrease with time in concurrence with the previous results. The tilts were mostly westward while on rare occasions the plasma bubbles tilted eastwards. The drifts were found to be relatively lesser on disturbed nights while the tilts appear to be marginally larger. The interdepletion distances (or bubble spacings) also showed a decreasing trend with time till midnight indicating that the bubbles approach each other with the passage of time. Such a behavior is not reported earlier and it seems to have important implications for understanding the time evolution of plasma bubbles. On occasions, the bubbles occurred in groups. An ionosonde operating over Indian dip equatorial site Tirunelveli (1.1°N dip latitude) was used to study the variations in the base height of the ionosphere during the plasma bubble observations. The ionosonde measurements indicate lack of significant pre-reversal enhancement (PRE) during geomagnetic quiet days in which the bubbles were observed.

  17. Determination of quinolones in plasma samples by capillary electrophoresis using solid-phase extraction.

    Science.gov (United States)

    Hernández, M; Borrull, F; Calull, M

    2000-06-09

    The potential of capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) have been investigated for the separation and quantitative determination of 10 quinolone antibiotics. The influence of different conditions, such as the buffer and pH of the electrolyte, the surfactant and the ion-pairing agents added to the electrolyte and the organic modifier were studied. A buffer consisting of 40 mM sodium tetraborate at pH 8.1 containing 10% (v/v) methanol was found to be a highly efficient electrophoretic system for separating lomefloxacin, enoxacin, norfloxacin, pipemidic acid, ofloxacin, piromidic acid, flumequine, oxolinic acid, cinoxacin and nalidixic acid. A solid-phase extraction method to remove the sample matrix (pig plasma samples) was developed on a C(18) cartridge using a mixture of methanol-water (70:30, v/v). The method is specific and reproducible and mean recoveries were in the range 94.0+/-4.2% and 123.3+/-4.1% for pig plasma samples over the range used. A linear relationship between concentration and peak area for each compound in pig plasma samples was obtained in the concentration range 5-20 mg l(-1) and detection limits were between 1.1 and 2.4 mg l(-1).

  18. Improving the sampling technique of arterialized capillary samples to obtain more accurate PaO2 measurements.

    Science.gov (United States)

    Wimpress, S; Vara, D D; Brightling, C E

    2005-01-01

    Arterialized earlobe capillary blood samples (ELCS) have been used as a measurement of blood gas status for over 20 years. There is general acceptance that there is a strong correlation and limits of agreement between arterial and arterialized blood samples with respect to pH and PaCO2. Although the correlation between the arterial and arterialized PaO2 is good, the limits of agreement poor. Our aim was to improve the accuracy of this technique in the measurement of PaO2 by simultaneously monitoring the oxygen saturation by pulse oximetry whilst taking an ELCS. We hypothesize that significant discrepancies between the SaO2 and SpO2 highlight either a poorly arterialized sample or an over aerated sample from air bubbles. We compared the SpO2 with the SaO2 of an arterial sample from 27 inpatients. We used the limits of agreement between these samples to define the degree of discordance we would accept between SaO2 and SpO2 before repeat ELCS. Subsequently, 252 consecutive patients attending our respiratory physiology unit over a six-month period had an ELCS and simultaneous SpO2. If there was a discrepancy between SaO2 and SpO2 of > 2% the ELCS was repeated. There was a good correlation and limits of agreement between the SpO2 and arterial SaO2 (r = 0.97, mean difference +/- 95% limits of agreement: 0.34 +/- 2.68). A difference of more than 2% between arterialized SaO2 and SpO2 was identified in 21 patients out of 252 (8.3%) with SaO2 higher in two and lower in 19 (r = 0.96, mean difference +/- 95% limits of agreement: 0.66 +/- 3.1). Repeat ELCS of these 21 samples reduced this discrepancy improving the concordance of the measurements (r = 0.98, mean difference +/- 95% limits of agreement: 0.47 +/- 1.0). In one case a difference of 3% remained between the saturations. We conclude that the addition of simultaneous pulse oximetry with ELCS will identify rogue measurements in about 8% of cases highlighting the need for repeat samples and thus increasing the accuracy of

  19. Post-glucose-load urinary C-peptide and glucose concentration obtained during OGTT do not affect oral minimal model-based plasma indices.

    Science.gov (United States)

    Jainandunsing, Sjaam; Wattimena, J L Darcos; Rietveld, Trinet; van Miert, Joram N I; Sijbrands, Eric J G; de Rooij, Felix W M

    2016-05-01

    The purpose of this study was to investigate how renal loss of both C-peptide and glucose during oral glucose tolerance test (OGTT) relate to and affect plasma-derived oral minimal model (OMM) indices. All individuals were recruited during family screening between August 2007 and January 2011 and underwent a 3.5-h OGTT, collecting nine plasma samples and urine during OGTT. We obtained the following three subgroups: normoglycemic, at risk, and T2D. We recruited South Asian and Caucasian families, and we report separate analyses if differences occurred. Plasma glucose, insulin, and C-peptide concentrations were analyzed as AUCs during OGTT, OMM estimate of renal C-peptide secretion, and OMM beta-cell and insulin sensitivity indices were calculated to obtain disposition indices. Post-glucose load glucose and C-peptide in urine were measured and related to plasma-based indices. Urinary glucose corresponded well with plasma glucose AUC (Cau r = 0.64, P oral (Cau r = -0.61, P indices in general nor in T2D patients (renal clearance range 0-2.1 %, with median 0.2 % of plasma glucose AUC). C-indices of urinary glucose to detect various stages of glucose intolerance were excellent (Cau 0.83-0.98; SA 0.75-0.89). The limited role of renal glucose secretion validates the neglecting of urinary glucose secretion in kinetic models of glucose homeostasis using plasma glucose concentrations. Both C-peptide and glucose in urine collected during OGTT might be used as non-invasive measures for endogenous insulin secretion and glucose tolerance state.

  20. Characteristics of seminal plasma and cryopreservation of anoa (Bubalus sp. semen obtained by electroejaculation

    Directory of Open Access Journals (Sweden)

    Yudi

    2011-03-01

    Full Text Available The population of anoa, which is an endemic fauna to Indonesia, was getting decrease caused by the illegal hunting and deforestation. Anoa is included in endangered species by IUCN, and Appendix I by CITES. The experiment aimed to characterize the seminal plasma contents and to cryopreserve the anoa semen for artificial insemination application in captivity. The experiment was carried out in Taman Safari Indonesia (Bogor. Semen was collected from 2 anesthetized males (4-10 years by electroejaculation. Seminal plasma gained by centrifugation of ejaculate (3000 rpm, 20 minutes, and then was evaluated the biochemical contents. Other ejaculates were evaluated macroscopically and microscopically, and then extended in Tris and Na-citrate media to a total concentration of 100 billion cells mL-1. Extended semen was stored at 4oC, and evaluated the motility and viability every 12 h. Frozen semen was made in Tris medium added with 5% of glycerol. The seminal plasma of anoa contained total lipid, Na, Ca and Mg higher than the buffalo, but its total protein, K and Cl were lower. Electrophoresis of seminal plasma using by SDS-PAGE method showed 10 bands of proteins (17-148 kDa. The motility and viability of chilled-extended semen in Tris and Na-citrate media were not significantly different (P > 0.05 during 72 h of evaluation. Extended semen in both of media may applicable for AI program for 24-48 h. Post thawing motility of frozen semen was still low, 26.00 ± 9.62%. Therefore, it is necessary to improve each stages of semen processing, so the motility will increased and resulted high pregnancy in AI program.

  1. Hair of the dog: obtaining samples from coyotes and wolves noninvasively

    Science.gov (United States)

    Ausband, David E.; Young, Julie; Fannin, Barbara; Mitchell, Michael S.; Stenglein, Jennifer L.; Waits, Lisette P.; Shivik, John A.

    2011-01-01

    Canids can be difficult to detect and their populations difficult to monitor. We tested whether hair samples could be collected from coyotes (Canis latrans) in Texas, USA and gray wolves (C. lupus) in Montana, USA using lure to elicit rubbing behavior at both man-made and natural collection devices. We used mitochondrial and nuclear DNA to determine whether collected hair samples were from coyote, wolf, or nontarget species. Both coyotes and wolves rubbed on man-made barbed surfaces but coyotes in Texas seldom rubbed on hanging barbed surfaces. Wolves in Montana showed a tendency to rub at stations where natural-material collection devices (sticks and debris) were present. Time to detection was relatively short (5 nights and 4 nights for coyotes and wolves, respectively) with nontarget and unknown species comprising approximately 26% of the detections in both locations. Eliciting rubbing behavior from coyotes and wolves using lures has advantages over opportunistic genetic sampling methods (e.g., scat transects) because it elicits a behavior that deposits a hair sample at a fixed sampling location, thereby increasing the efficiency of sampling for these canids. Hair samples from rub stations could be used to provide estimates of abundance, measures of genetic diversity and health, and detection-nondetection data useful for cost-effective population monitoring.

  2. Characterization of duplex stainless steel weld metals obtained by hybrid plasma-gas metal arc welding

    Directory of Open Access Journals (Sweden)

    Koray Yurtisik

    2013-09-01

    Full Text Available Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex microstructure without compromising the welding efficiency. 11.1 mm-thick standard duplex stainless steel plates were joined in a single-pass using this novel technique. Same plates were also subjected to conventional gas metal arc and plasma arc welding processes, providing benchmarks for the investigation of the weldability of the material. In the first place, the hybrid welding process enabled us to achieve less heat input compared to gas metal arc welding. Consequently, the precipitation of secondary phases, which are known to be detrimental to the toughness and corrosion resistance of duplex stainless steels, was significantly suppressed in both fusion and heat affected zones. Secondly, contrary to other keyhole techniques, proper cooling time and weld metal chemistry were achieved during the process, facilitating sufficient reconstructive transformation of austenite in the ferrite phase.

  3. Analysis of bioethanol samples through Inductively Coupled Plasma Mass Spectrometry with a total sample consumption system

    Science.gov (United States)

    Sánchez, Carlos; Lienemann, Charles-Philippe; Todolí, Jose-Luis

    2016-10-01

    Bioethanol real samples have been directly analyzed through ICP-MS by means of the so called High Temperature Torch Integrated Sample Introduction System (hTISIS). Because bioethanol samples may contain water, experiments have been carried out in order to determine the effect of ethanol concentration on the ICP-MS response. The ethanol content studied went from 0 to 50%, because higher alcohol concentrations led to carbon deposits on the ICP-MS interface. The spectrometer default spray chamber (double pass) equipped with a glass concentric pneumatic micronebulizer has been taken as the reference system. Two flow regimes have been evaluated: continuous sample aspiration at 25 μL min- 1 and 5 μL air-segmented sample injection. hTISIS temperature has been shown to be critical, in fact ICP-MS sensitivity increased with this variable up to 100-200 °C depending on the solution tested. Higher chamber temperatures led to either a drop in signal or a plateau. Compared with the reference system, the hTISIS improved the sensitivities by a factor included within the 4 to 8 range while average detection limits were 6 times lower for the latter device. Regarding the influence of the ethanol concentration on sensitivity, it has been observed that an increase in the temperature was not enough to eliminate the interferences. It was also necessary to modify the torch position with respect to the ICP-MS interface to overcome them. This fact was likely due to the different extent of ion plasma radial diffusion encountered as a function of the matrix when working at high chamber temperatures. When the torch was moved 1 mm plasma down axis, ethanolic and aqueous solutions provided statistically equal sensitivities. A preconcentration procedure has been applied in order to validate the methodology. It has been found that, under optimum conditions from the point of view of matrix effects, recoveries for spiked samples were close to 100%. Furthermore, analytical concentrations for real

  4. Surveillance cultures of samples obtained from biopsy channels and automated endoscope reprocessors after high-level disinfection of gastrointestinal endoscopes

    Directory of Open Access Journals (Sweden)

    Chiu King-Wah

    2012-09-01

    Full Text Available Abstract Background The instrument channels of gastrointestinal (GI endoscopes may be heavily contaminated with bacteria even after high-level disinfection (HLD. The British Society of Gastroenterology guidelines emphasize the benefits of manually brushing endoscope channels and using automated endoscope reprocessors (AERs for disinfecting endoscopes. In this study, we aimed to assess the effectiveness of decontamination using reprocessors after HLD by comparing the cultured samples obtained from biopsy channels (BCs of GI endoscopes and the internal surfaces of AERs. Methods We conducted a 5-year prospective study. Every month random consecutive sampling was carried out after a complete reprocessing cycle; 420 rinse and swabs samples were collected from BCs and internal surface of AERs, respectively. Of the 420 rinse samples collected from the BC of the GI endoscopes, 300 were obtained from the BCs of gastroscopes and 120 from BCs of colonoscopes. Samples were collected by flushing the BCs with sterile distilled water, and swabbing the residual water from the AERs after reprocessing. These samples were cultured to detect the presence of aerobic and anaerobic bacteria and mycobacteria. Results The number of culture-positive samples obtained from BCs (13.6%, 57/420 was significantly higher than that obtained from AERs (1.7%, 7/420. In addition, the number of culture-positive samples obtained from the BCs of gastroscopes (10.7%, 32/300 and colonoscopes (20.8%, 25/120 were significantly higher than that obtained from AER reprocess to gastroscopes (2.0%, 6/300 and AER reprocess to colonoscopes (0.8%, 1/120. Conclusions Culturing rinse samples obtained from BCs provides a better indication of the effectiveness of the decontamination of GI endoscopes after HLD than culturing the swab samples obtained from the inner surfaces of AERs as the swab samples only indicate whether the AERs are free from microbial contamination or not.

  5. Monte Carlo Sampling of Negative-temperature Plasma States

    Energy Technology Data Exchange (ETDEWEB)

    John A. Krommes; Sharadini Rath

    2002-07-19

    A Monte Carlo procedure is used to generate N-particle configurations compatible with two-temperature canonical equilibria in two dimensions, with particular attention to nonlinear plasma gyrokinetics. An unusual feature of the problem is the importance of a nontrivial probability density function R0(PHI), the probability of realizing a set {Phi} of Fourier amplitudes associated with an ensemble of uniformly distributed, independent particles. This quantity arises because the equilibrium distribution is specified in terms of {Phi}, whereas the sampling procedure naturally produces particles states gamma; {Phi} and gamma are related via a gyrokinetic Poisson equation, highly nonlinear in its dependence on gamma. Expansion and asymptotic methods are used to calculate R0(PHI) analytically; excellent agreement is found between the large-N asymptotic result and a direct numerical calculation. The algorithm is tested by successfully generating a variety of states of both positive and negative temperature, including ones in which either the longest- or shortest-wavelength modes are excited to relatively very large amplitudes.

  6. Spectrochemical analysis of powdered biological samples using transversely excited atmospheric carbon dioxide laser plasma excitation

    Science.gov (United States)

    Zivkovic, Sanja; Momcilovic, Milos; Staicu, Angela; Mutic, Jelena; Trtica, Milan; Savovic, Jelena

    2017-02-01

    The aim of this study was to develop a simple laser induced breakdown spectroscopy (LIBS) method for quantitative elemental analysis of powdered biological materials based on laboratory prepared calibration samples. The analysis was done using ungated single pulse LIBS in ambient air at atmospheric pressure. Transversely-Excited Atmospheric pressure (TEA) CO2 laser was used as an energy source for plasma generation on samples. The material used for the analysis was a blue-green alga Spirulina, widely used in food and pharmaceutical industries and also in a few biotechnological applications. To demonstrate the analytical potential of this particular LIBS system the obtained spectra were compared to the spectra obtained using a commercial LIBS system based on pulsed Nd:YAG laser. A single sample of known concentration was used to estimate detection limits for Ba, Ca, Fe, Mg, Mn, Si and Sr and compare detection power of these two LIBS systems. TEA CO2 laser based LIBS was also applied for quantitative analysis of the elements in powder Spirulina samples. Analytical curves for Ba, Fe, Mg, Mn and Sr were constructed using laboratory produced matrix-matched calibration samples. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used as the reference technique for elemental quantification, and reasonably well agreement between ICP and LIBS data was obtained. Results confirm that, in respect to its sensitivity and precision, TEA CO2 laser based LIBS can be successfully applied for quantitative analysis of macro and micro-elements in algal samples. The fact that nearly all classes of materials can be prepared as powders implies that the proposed method could be easily extended to a quantitative analysis of different kinds of materials, organic, biological or inorganic.

  7. Structure of organometallic compounds obtained by plasma of titanium isopropoxide; Estructura de compuestos organometalicos obtenidos por plasma de isopropoxido de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Arreola R, M. L.

    2012-07-01

    This work presents a study on the synthesis and characterization of organometallic compounds of titanium oxide obtained from glow discharges of titanium tetraisopropoxide (TTIP) and water on glass and polyethylene. The objective is the synthesis of titanium oxide particles which can be fixed on different supports for use in further studies of contaminants degradation in effluent streams. The synthesis was carried out by plasma in a glass tubular reactor of 750 cm{sup 3} and 15 cm length at 10{sup -1} mbar with power between 100 and 150 W during 2, 3 and 4 h. The precursors were TTIP and water vapor. TTIP is an organometallic compound composed of a central atom of Ti surrounded by 4 O atoms, which in turn are connected with chains of 3 C (propane s). The objective is the use of plasma collisions to separate the organic and inorganic phases of TTIP, so that both structure independently in a single material. The result was the formation of white titanium oxide powder composed with agglomerates of spherical particles with average diameter between 160 and 452 nm adhered to small films. The agglomerates have a tendency to change from film to particles with the energy applied to the synthesis. The study of the chemical structure showed a great presence of O{sub 2}-Ti-O{sub 2} (Ti surrounded by O) which can be found in most titanium oxides. Other chemical groups belonging to the organic phase were C=C=C, C=C=O and C{sub 2}-C-Ch appearing from the dehydrogenation of TTIP, which can be a possible precursor of this reactions kind. The structural superficial analyses showed that the atomic composition varies according to type of substrate used. The greatest content of Ti was obtained on glass substrates. However, the synthesis conditions had not evident effect in the participation of chemical states found in the inorganic phase. The crystalline studies indicated that the material is amorphous, although the de convoluted X-ray spectra showed that the synthesized titanium oxides

  8. [Methods to obtain platelet-rich plasma and osteoinductive therapeutic use].

    Science.gov (United States)

    Moreno, Raquel; Gaspar Carreño, Marisa; Jiménez Torres, José; Alonso Herreros, José María; Villimar, Ana; López Sánchez, Piedad

    2015-05-01

    Introduccion: El Plasma Rico en Plaquetas (PRP) es un plasma autólogo con una cifra de plaquetas superior a la del plasma basal, por haber sido sometido a algún proceso de extracción y concentración. El empleo del PRP como osteoinductor es conflictivo dado que, no existen estudios clínicos rigurosos que permita extraer conclusiones firmes respecto a su utilidad. Objetivo: Proporcionar información sobre las técnicas de obtención del PRP, las consideraciones legales sobre su obtención y empleo, el mecanismo de acción molecular, así como la evidencia disponible sobre su seguridad y tolerancia. Resultado: El PRP se obtiene de forma manual, mediante “técnica abierta”, o mediante kits desechables con “técnica cerrada”, siendo estos últimos productos sanitarios clasificados como IIa. La Agencia Española de Medicamentos y Productos Sanitarios (AEMPS) considera el PRP como medicamento, estableciendo unos requisitos mínimos para garantizar su seguridad, trazabilidad, farmacovigiliancia e información. El PRP, por su elevado contenido en factores de crecimiento, reúne cualidades para ser un potente papel osteoinductor, capaz de acelerar la consolidación de fracturas o de osteointegrar rápida y eficientemente distintos tipos de implantes óseos. La tolerancia a la infiltración es generalmente buena, aunque hay que tener en cuenta su elevado potencial angiogénico. Conclusiones: El PRP, dadas las características de producción y aplicación, es considerado por la AEMPS como un medicamento de dispensación bajo prescripción médica restringida, por lo que los servicios de farmacia hospitalaria deberían, cuando menos, supervisar su gestión y manipulación.

  9. Sample controlled reaction temperature (SCRT): Controlling the phase composition of silicon nitride obtained by carbothermal reduction

    Energy Technology Data Exchange (ETDEWEB)

    Alcala, M.D.; Criado, J.M.; Real, C. [Instituto de Ciencia de Materiales de Sevilla, c/Americo Vespucio s/n; Isla de La Cartuja, 41092 Sevilla (Spain)

    2002-07-01

    Carbothermal reduction of silica is one of the most common methods of producing Si{sub 3}N{sub 4} powders. The experimental conditions have an important influence on the structure of the final product, especially the balance of {alpha}- to {beta}- Si{sub 3}N{sub 4}. The Sample Controlled Reaction Temperature method describes here has permitted to conclude that the phase composition of the silicon nitride is governed by the partial pressure of CO in the close vicinity of the sample. Moreover, the control of this parameter has an important influence on particle size and morphology of the final product. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  10. Analyses of human colonic mucus obtained by an in vivo sampling technique

    NARCIS (Netherlands)

    Hamer, H.M.; Jonkers, D.M.A.E.; Loof, A.; Houtvin, S.A.L.W. van; Troost, F.J.; Venema, K.; Kodde, A.; Koek, G.H.; Schipper, R.G.; Heerde, W.L. van; Brummer, R.J.

    2009-01-01

    Background: The mucus layer is an important dynamic component of the epithelial barrier. It contains mucin glycoproteins and other compounds secreted by the intestinal epithelium, such as secretory IgA. However, a standardized in vivo sampling technique of mucus in humans is not yet available. Aim:

  11. A noninvasive hair sampling technique to obtain high quality DNA from elusive small mammals.

    Science.gov (United States)

    Henry, Philippe; Henry, Alison; Russello, Michael A

    2011-03-13

    Noninvasive genetic sampling approaches are becoming increasingly important to study wildlife populations. A number of studies have reported using noninvasive sampling techniques to investigate population genetics and demography of wild populations. This approach has proven to be especially useful when dealing with rare or elusive species. While a number of these methods have been developed to sample hair, feces and other biological material from carnivores and medium-sized mammals, they have largely remained untested in elusive small mammals. In this video, we present a novel, inexpensive and noninvasive hair snare targeted at an elusive small mammal, the American pika (Ochotona princeps). We describe the general set-up of the hair snare, which consists of strips of packing tape arranged in a web-like fashion and placed along travelling routes in the pikas' habitat. We illustrate the efficiency of the snare at collecting a large quantity of hair that can then be collected and brought back to the lab. We then demonstrate the use of the DNA IQ system (Promega) to isolate DNA and showcase the utility of this method to amplify commonly used molecular markers including nuclear microsatellites, amplified fragment length polymorphisms (AFLPs), mitochondrial sequences (800bp) as well as a molecular sexing marker. Overall, we demonstrate the utility of this novel noninvasive hair snare as a sampling technique for wildlife population biologists. We anticipate that this approach will be applicable to a variety of small mammals, opening up areas of investigation within natural populations, while minimizing impact to study organisms.

  12. Molecular detection of Streptococcus agalactiae in bovine raw milk samples obtained directly from bulk tanks.

    Science.gov (United States)

    Elias, Acácia Orieth; Cortez, Adriana; Brandão, Paulo Eduardo; da Silva, Rodrigo Costa; Langoni, Helio

    2012-08-01

    Mastitis is the most common infectious disease affecting dairy cattle; in addition, it remains the most economically important disease of dairy industries around the world. Streptococcus agalactiae, a contagious pathogen associated with subclinical mastitis, is highly infectious. This bacterium can cause an increase in bulk tank bacterial counts (BTBC) and bulk tank somatic cell counts (BTSCC). The microbiological identification of S. agalactiae in samples from bulk tanks is an auxiliary method to control contagious mastitis. Thus, there are some limitations for time-consuming cultures or identification methods and additional concerns about the conservation and transport of samples. Bulk tank samples from 247 dairy farms were cultured and compared through polymerase chain reaction (PCR), directed to 16S rRNA genes of S. agalactiae, followed by BTBC and S. agalactiae isolation. The mean value of BTBC was 1.08×10(6) CFU mL(-1) and the bacterium was identified through the microbiological method in 98 (39.7%; CI(95%)=33.8-45.9%) and through PCR in 110 (44.5%; CI(95%)=38.5-50.8%) samples. Results indicated sensitivity of 0.8571±0.0353 (CI(95%)=0.7719-0.9196) and specificity of 0.8255±0.0311 (CI(95%)=0.7549-0.8827). The lack of significant difference between microbiological and molecular results (κ=0.6686±0.0477 and CI(95%)=0.5752-0.7620) indicated substantial agreement between the methods. This suggests that PCR can be used for bulk tank samples to detect contagious mastitis caused by S. agalactiae.

  13. The effect of lidocaine on in vitro neutrophil and endothelial adhesion molecule expression induced by plasma obtained during tourniquet-induced ischaemia and reperfusion.

    LENUS (Irish Health Repository)

    Lan, W

    2012-02-03

    BACKGROUND: Changes in neutrophil and endothelial adhesion molecule expression occur during perioperative ischaemia and reperfusion (I\\/R) injury. We investigated the effects of lidocaine on neutrophil-independent changes in neutrophil and endothelial adhesion molecule expression associated with tourniquet-induced I\\/R. METHODS: Plasma was obtained from venous blood samples (tourniquet arm) taken before (baseline), during, 15 min, 2 and 24 h following tourniquet release in seven patients undergoing elective upper limb surgery with tourniquet application. Isolated neutrophils from healthy volunteers (n = 7) were pretreated in the presence or absence of lidocaine (0.005, 0.05 and 0.5 mg mL(-1) for 1 h, and then incubated with I\\/R plasma for 2 h. Human umbilical vein endothelial cells (HUVECs) were pretreated in the presence or absence of lidocaine (0.005, 0.05 and 0.5 mg mL(-1)) for 1 h, and then incubated with the plasma for 4 h. Adhesion molecule expression was estimated using flow cytometry. Data were analysed using ANOVA and post hoc Student-Newman-Keuls tests. RESULTS: I\\/R plasma (withdrawn 15 min following tourniquet release) increased isolated neutrophil CD11b (P = 0.03), CD18 (P = 0.01) and endothelial intercellular adhesion molecule-1 (ICAM-1) (P = 0.008) expression compared to baseline. CD11b, CD18 and ICAM-1 expression on lidocaine (0.005 mg mL(-1)) treated neutrophils was similar to control. CD11b (P < 0.001), CD18 (P = 0.03) and ICAM-1 (P = 0.002) expression on lidocaine (0.05 mg mL(-1)) treated neutrophils and HUVECs was less than that on controls. CONCLUSION: Increased in vitro neutrophil and endothelial cell adhesion molecule expression on exposure to plasma obtained during the early reperfusion phase is diminished by lidocaine at greater than clinically relevant plasma concentrations.

  14. Pumping time required to obtain tube well water samples with aquifer characteristic radon concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Ricardo, Carla Pereira; Oliveira, Arno Heeren de, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear; Rocha, Zildete; Palmieri, Helena E.L.; Linhares, Maria G.M.; Menezes, Maria Angela B.C., E-mail: rochaz@cdtn.br, E-mail: help@cdtn.br, E-mail: mgml@cdtn.br, E-mail: menezes@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Radon is an inert noble gas, which comes from the natural radioactive decay of uranium and thorium in soil, rock and water. Radon isotopes emanated from radium-bearing grains of a rock or soil are released into the pore space. Radon that reaches the pore space is partitioned between the gaseous and aqueous phases. Thus, the groundwater presents a radon signature from the rock that is characteristic of the aquifer. The characteristic radon concentration of an aquifer, which is mainly related to the emanation, is also influenced by the degree of subsurface degassing, especially in the vicinity of a tube well, where the radon concentration is strongly reduced. Looking for the required pumping time to take a tube well water sample that presents the characteristic radon concentration of the aquifer, an experiment was conducted in an 80 m deep tube well. In this experiment, after twenty-four hours without extraction, water samples were collected periodically, about ten minutes intervals, during two hours of pumping time. The radon concentrations of the samples were determined by using the RAD7 Electronic Radon Detector from Durridge Company, a solid state alpha spectrometric detector. It was realized that the necessary time to reach the maximum radon concentration, that means the characteristic radon concentration of the aquifer, is about sixty minutes. (author)

  15. Qualitative Parameters of Pasture Samples Obtained from Different Farms in 2012

    Directory of Open Access Journals (Sweden)

    Kamila Pejchova

    2013-10-01

    Full Text Available The aim of this experiment was a representation of chemical composition of pasture samples from different farms and NDF degradability examination by in sacco method. The experiment took place on three farms with different altitudes. All samples were analyzed for ash, crude protein (CP, crude fiber (CF, neutral detergent fiber (NDF and acid detergent fiber (ADF. NDF degradability was evaluated by in sacco method in chosen herbs from samples of pasture. During the grazing season in a sward reduces the content of NL and at the same time increases the content of CF. During the pasture period declines the share of clovers in growth and on the contrary significantly higher proportion of grasses. The highest NDF degradability all the time of incubation in the rumen was in Taraxacum officinale and varied from 453.1 g.kg-1 NDF in 6 h of incubation to 882.1 g.kg-1 NDF in 72 h of incubation. The lowest NDF degradability was in Rumex obtusifolius (198.1 to 581.8 g.kg-1 NDF and Ranunculus acris (278.6 to 566 g.kg-1 NDF.Differences between farms are minimal.

  16. Spectroscopic ellipsometry analysis of silicon nanotips obtained by electron cyclotron resonance plasma etching.

    Science.gov (United States)

    Mendoza-Galván, Arturo; Järrendahl, Kenneth; Arwin, Hans; Huang, Yi-Fan; Chen, Li-Chyong; Chen, Kuei-Hsien

    2009-09-10

    Silicon nanotips fabricated by electron cyclotron resonance plasma etching of silicon wafers are studied by spectroscopic ellipsometry. The structure of the nanotips is composed of columns 100-140 nm wide and spaced by about 200 nm. Ellipsometry data covering a wide spectral range from the midinfrared to the visible are described by modeling the nanotip layer as a graded uniaxial film using the Bruggeman effective medium approximation. The ellipsometry data in the infrared range reveal two absorption bands at 754 and 955 cm(-1), which cannot be resolved with transmittance measurements. These bands indicate that the etching process is accompanied with formation of carbonaceous SiC and CH(n) species that largely modify the composition of the original crystalline silicon material affecting the optical response of the nanotips.

  17. Obtaining the high-current low-energy electron beams in the systems with a plasma emitter

    CERN Document Server

    Devyatkov, V N; Shchanin, P M

    2001-01-01

    Using gas filled diodes with arc and glow-discharge base plasma emitters one investigated into generation and transfer of high-current electron beams. Using a diode with arc discharge base plasma emitter at 15 kV accelerating voltage one obtained a space charge compensated with up to 1 kA current compressed by proper magnetic field from 8 cm diameter up to 1 cm and transported at over 20 cm distance with 70% efficiency. Using a diode with a glow-discharge one obtained a 80 A current and up to 100 A/cm current density beam. In a weak axial magnetic field with B=0.015 T induction such a beam is transported at 30 cm distance

  18. Scale-up of the process to obtain functional ingredients based in plasma protein concentrates from porcine blood.

    Science.gov (United States)

    Parés, Dolors; Toldrà, Mònica; Saguer, Elena; Carretero, Carmen

    2014-01-01

    The feasibility of a scaled-up process to obtain two protein concentrates from porcine blood plasma, i.e. serum and albumin, for use as functional food ingredients was assessed. The process consisted of fractionating plasma proteins by salting out, concentrating and purifying fractions by means of membrane technology, and subsequently dehydrating through spray-drying. The fractionation process allowed a good isolation of the desired proteins, which were then concentrated and desalted in a tangential flow filtration (TFF) process combining ultra and diafiltration. Purification, pre-concentration and dehydration were successfully achieved. The functional properties of dehydrated serum and albumin were determined. As compared to the same hemoderivatives obtained by a lab-scale production system, serum maintained the gelling properties; albumin exhibited similar foaming properties; and both serum and albumin concentrates showed slightly improved emulsifying properties.

  19. Veterinary antibiotic resistance, residues, and ecological risks in environmental samples obtained from poultry farms, Egypt.

    Science.gov (United States)

    Dahshan, Hesham; Abd-Elall, Amr Mohamed Mohamed; Megahed, Ayman Mohamed; Abd-El-Kader, Mahdy A; Nabawy, Ehab Elsayed

    2015-02-01

    In Egypt, poultry production constitutes one of the main sources of pollution with veterinary antibiotics (VAs) into the environment. About 80 % of meat production in Egypt is of poultry origin, and the potential environmental risks associated with the use of VAs in these farms have not yet been properly evaluated. Thus, the main purpose of this research was to evaluate the prevalence of antibiotic-resistant enteric key bacteria and the incidence of residual antibiotics in poultry farm environmental samples and to determine whether fertilizing soils with poultry litter from farms potentially brings ecological risks. From December 2011 to September 2012, a total of 225 litter, bird dropping, and water samples were collected from 75 randomly selected boiler poultry farms. A high prevalence of Escherichia coli (n = 179; 79.5 %) in contrast to the low prevalence of Salmonella spp. (n = 7; 3.1 %) was detected. Amongst E. coli isolates, serotypes O142:K86, O125:K70, O91:K, and O119:K69 were the most common. Meanwhile, Salmonella enterica serotypes emek and enteritidis were recovered. The antibiograms using the disc diffusion method revealed significantly more common resistant and multi-resistant isolates in broiler poultry farms. Residues of tetracycline and ciprofloxacin were detected at 2.125 and 1.401 mg kg(-1) mean levels, respectively, in environmental samples contaminated with E. coli-resistant strains by HPLC. The risk evaluations highlighted that tetracycline residues in poultry litter significantly display environmental risks with a hazard quotient value above 1 (1.64). Our study implies that ineffective implementation of veterinary laws which guide and guard against incorrect VA usage may potentially bring health and environmental risks.

  20. Changes in red blood cell osmotic fragility induced by total plasma and plasma fractions obtained from rats bearing progressive and regressive variants of the Walker 256 tumor

    Directory of Open Access Journals (Sweden)

    Cavalcanti T.C.

    2003-01-01

    Full Text Available Two variants (A and B of the widely employed Walker 256 rat tumor cells are known. When inoculated sc, the A variant produces solid, invasive, highly metastasizing tumors that cause severe systemic effects and death. We have obtained a regressive variant (AR whose sc growth is slower, resulting in 70-80% regression followed by development of immunity against A and AR variants. Simultaneously with the beginning of tumor regression, a temporary anemia developed (~8 days duration, accompanied by marked splenomegaly (~300% and changes in red blood cell osmotic fragility, with mean corpuscular fragility increasing from 4.1 to 6.5 g/l NaCl. The possibility was raised that plasma factors associated with the immune response induced these changes. In the present study, we identify and compare the osmotic fragility increasing activity of plasma fractions obtained from A and AR tumor bearers at different stages of tumor development. The results showed that by day 4 compounds precipitating in 60% (NH42SO4 and able to increase red blood cell osmotic fragility appeared in the plasma of A and AR tumor bearers. Later, these compounds disappeared from the plasma of A tumor bearers but slightly increased in the plasma of AR tumor bearers. Furthermore, by day 10, compounds precipitating between 60 and 80% (NH42SO4 and with similar effects appeared only in plasma of AR tumor bearers. The salt solubility, production kinetics and hemolytic activity of these compounds resemble those of the immunoglobulins. This, together with their preferential increase in rats bearing the AR variant, suggest their association with an immune response against this tumor.

  1. Elevated phospholipase A2 activities in plasma samples from multiple cancers.

    Directory of Open Access Journals (Sweden)

    Hui Cai

    Full Text Available Only in recent years have phospholipase A2 enzymes (PLA2s emerged as cancer targets. In this work, we report the first detection of elevated PLA2 activities in plasma from patients with colorectal, lung, pancreatic, and bladder cancers as compared to healthy controls. Independent sets of clinical plasma samples were obtained from two different sites. The first set was from patients with colorectal cancer (CRC; n = 38 and healthy controls (n = 77. The second set was from patients with lung (n = 95, bladder (n = 31, or pancreatic cancers (n = 38, and healthy controls (n = 79. PLA2 activities were analyzed by a validated quantitative fluorescent assay method and subtype PLA2 activities were defined in the presence of selective inhibitors. The natural PLA2 activity, as well as each subtype of PLA2 activity was elevated in each cancer group as compared to healthy controls. PLA2 activities were increased in late stage vs. early stage cases in CRC. PLA2 activities were not influenced by sex, smoking, alcohol consumption, or body-mass index (BMI. Samples from the two independent sites confirmed the results. Plasma PLA2 activities had approximately 70% specificity and sensitivity to detect cancer. The marker and targeting values of PLA2 activity have been suggested.

  2. Determination of trovafloxacin and marbofloxacin in sheep plasma samples by HPLC using UV detection.

    Science.gov (United States)

    Mahmood, Adnan H; Medley, Gregory A; Grice, Jeffrey E; Liu, Xin; Roberts, Michael S

    2012-03-25

    A simple and rapid high performance liquid chromatographic method was developed, validated and applied for the simultaneous determination of marbofloxacin (MBX) and trovafloxacin (TVX) in sheep plasma. Samples were extracted with 20% perchloric acid and MBX and TVX were separated on a C(18) column using a gradient mobile phase system consisting of 17.5mM of NaH(2)PO(4) and 1.5mM of tetrabutylammonium hydroxide aqueous solution, pH 3 (A) and 50% acetonitrile and 50% methanol (B), with UV detection at 293 and 270 nm. The retention times of MBX and TVX were 4.9 and 6.6 min respectively. The detection and quantification limits for MBX and TVX were 2 ng/mL and 10 ng/mL respectively for both compounds. The calibration curves were linear over a concentration range of 10-50,000 ng/mL for both antibiotics. The linearity, precision, accuracy, recovery and stability of the assay were evaluated from spiked sheep plasma. The method was successfully applied to sheep plasma samples obtained from MBX and TVX pharmacokinetic studies.

  3. Thermal analysis of the influence of the support in the superficial treatment by plasma of cylindrical samples

    Energy Technology Data Exchange (ETDEWEB)

    Belisio, A.S.; Lima, J.A.; Alves Junior, C. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica]. E-mails: abelisio@yahoo.com.br; jalima@dem.ufrn.br; alvesjr@dem.ufrn.br

    2008-07-01

    Different of the conventional processes of heating, that is, transport, convection, and radiation, heat transfer in heating process by plasma also occur also by collisions of particles, in other words, through the transfer heat motion ions for the surface of the sample, the kinetic energy, and potential those particles, as well as the enthalpy of the chemical reactions involved in the surface. In thermal plasmas, that transfer can to be simplified initially through general energy balance between plasma and samples. However, existent models of temperature distribution are in its majority unidimensional and it do not analyze, mainly, support influence on sample in the heating process by r plasma. In that way, with the mark of analyzing the temperature distribution in the samples submitted to polarization voltage of 706 V, 744 V and 790 V, as well as process heating support influence analysis those samples, the present work developed a code computational for a transient (2D-t) two-dimensional model, destined to the simulation of the heat transfer during heating phases and cooling in superficial process of treatment by plasma in cylindrical samples of copper, being considered the configuration of hollow cathode and the presence of a support. The model computational serves as a tool in the predict of the final properties of treated samples, well as in the specification of the parameters of the heating processes by plasma. In the developed model was considered that the physical samples properties were variable, functions of the temperature field. The results obtained through simulation are leaning and validated in experimental and theoretical data available in the literature, as well as, in information of tests accomplished in Lab Plasma/ UFRN. (author)

  4. Signal Processing and Sampling Method for Obtaining Time Series Corresponding to Higher Order Derivatives

    Directory of Open Access Journals (Sweden)

    Andreea Sterian

    2010-01-01

    accuracy some significant quantities corresponding to the dynamic system. For fast phenomena, such significant quantities are represented by the derivatives of the received signals. In case of advanced computer modeling, the received signal should be filtered and converted into a time series corresponding to the estimated values for the dynamic system through a sampling procedure. This paper will show that present-day methods for computing in a robust manner the first derivative of a received signal (using an oscillating system working on a limited time interval and a supplementary differentiation method can be extended to the robust computation of higher order derivatives of the received signal by using a specific set of second-order oscillating systems (working also on limited time intervals so as estimative values for higher-order derivatives are to be directly generated (avoiding the necessity of additional differentiation or amplifying procedures, which represent a source of supplementary errors in present-day methods.

  5. Spiders and harvestmen on tree trunks obtained by three sampling methods

    Directory of Open Access Journals (Sweden)

    Machač, Ondřej

    2016-04-01

    Full Text Available We studied spiders and harvestmen on tree trunks using three sampling methods. In 2013, spider and harvestman research was conducted on the trunks of selected species of deciduous trees (linden, oak, maple in the town of Přerov and a surrounding floodplain forest near the Bečva River in the Czech Republic. Three methods were used to collect arachnids (pitfall traps with a conservation fluid, sticky traps and cardboard pocket traps. Overall, 1862 spiders and 864 harvestmen were trapped, represented by 56 spider species belonging to 15 families and seven harvestman species belonging to one family. The most effective method for collecting spider specimens was a modified pitfall trap method, and in autumn (September to October a cardboard band method. The results suggest a high number of spiders overwintering on the tree bark. The highest species diversity of spiders was found in pitfall traps, evaluated as the most effective method for collecting harvestmen too.

  6. Switchable hydrophobic-hydrophilic layer obtained onto porous alumina by plasma-enhanced fluorination

    Institute of Scientific and Technical Information of China (English)

    A.TRESSAUD; C.LABRUG(E)RE; E.DURAND; C.BRIGOULEIX; H.ANDRIESSEN

    2009-01-01

    Conventional lithographic printing processes using porous alumina for offset applications generally use "wet" routes. Recently "dry" processes have been developed which are based on a heat-induced hydrophilic/oleophilic conversion of one or more layers of the coating so that a stronger affinity to-wards ink or water fountain is created at the exposed areas with respect to the surface of the unex-posed coating. Treatments involving rf plasma-enhanced fluorination (PEF) constitute exceptional tools for modifying the surface properties of materials. Many advantages of these techniques can be indeed outlined, when compared to more conventional methods: room-temperature reactions, chemical modi-fications limited to surface only without changing the bulk properties, possible non-equilibrium reac-tions. The influence of PEF treatments on porous alumina layer used in printing plates has been tested with various fluorinated gases (CF4, C3F8and C4F8) and characterized by XPS. The hydrophobic prop-erties of the fluorinated layer have been deduced from contact angle measurements. Using C4Fs rf-PEF treatment, the outmost surface of the hydrophilic alumina substrate used for lithographic printing is hydrophobized, or in other words, the hydrophilic substrate is converted into a support with hydro-phobic properties. Once being hydrophobized, the surface layer may be rendered hydrophilic using a heat pulse, thus giving rise to switchable hydrophobic-hydrophilic properties of the material.

  7. Biomimetic apatite-based composite materials obtained by spark plasma sintering (SPS): physicochemical and mechanical characterizations.

    Science.gov (United States)

    Brouillet, Fabien; Laurencin, Danielle; Grossin, David; Drouet, Christophe; Estournes, Claude; Chevallier, Geoffroy; Rey, Christian

    2015-08-01

    Nanocrystalline calcium phosphate apatites are biomimetic compounds analogous to bone mineral and are at the origin of the bioactivity of most biomaterials used as bone substitutes. Their unique surface reactivity originates from the presence of a hydrated layer containing labile ions (mostly divalent ones). So the setup of 3D biocompatible apatite-based bioceramics exhibiting a high reactivity requests the development of «low» temperature consolidation processes such as spark plasma sintering (SPS), in order to preserve the characteristics of the hydrated nanocrystals. However, mechanical performances may still need to be improved for such nanocrystalline apatite bioceramics, especially in view of load-bearing applications. The reinforcement by association with biopolymers represents an appealing approach, while preserving the advantageous biological properties of biomimetic apatites. Herein, we report the preparation of composites based on biomimetic apatite associated with various quantities of microcrystalline cellulose (MCC, 1-20 wt%), a natural fibrous polymer. The SPS-consolidated composites were analyzed from both physicochemical (X-ray diffraction, Fourier transform infrared, solid state NMR) and mechanical (Brazilian test) viewpoints. The preservation of the physicochemical characteristics of apatite and cellulose in the final material was observed. Mechanical properties of the composite materials were found to be directly related to the polymer/apatite ratios and a maximum crushing strength was reached for 10 wt% of MCC.

  8. Switchable hydrophobic-hydrophilic layer obtained onto porous alumina by plasma-enhanced fluorination

    Institute of Scientific and Technical Information of China (English)

    A.; TRESSAUD; C.; LABRUGèRE; E.; DURAND; C.; BRIGOULEIX; H.; ANDRIESSEN

    2009-01-01

    Conventional lithographic printing processes using porous alumina for offset applications generally use "wet" routes. Recently "dry" processes have been developed which are based on a heat-induced hydrophilic/oleophilic conversion of one or more layers of the coating so that a stronger affinity to-wards ink or water fountain is created at the exposed areas with respect to the surface of the unex-posed coating. Treatments involving rf plasma-enhanced fluorination (PEF) constitute exceptional tools for modifying the surface properties of materials. Many advantages of these techniques can be indeed outlined, when compared to more conventional methods: room-temperature reactions, chemical modi-fications limited to surface only without changing the bulk properties, possible non-equilibrium reac-tions. The influence of PEF treatments on porous alumina layer used in printing plates has been tested with various fluorinated gases (CF4, C3F8 and C4F8) and characterized by XPS. The hydrophobic prop-erties of the fluorinated layer have been deduced from contact angle measurements. Using C4F8 rf-PEF treatment, the outmost surface of the hydrophilic alumina substrate used for lithographic printing is hydrophobized, or in other words, the hydrophilic substrate is converted into a support with hydro-phobic properties. Once being hydrophobized, the surface layer may be rendered hydrophilic using a heat pulse, thus giving rise to switchable hydrophobic-hydrophilic properties of the material.

  9. Normalization of gene expression measurement of tissue samples obtained by transurethral resection of bladder tumors

    Directory of Open Access Journals (Sweden)

    Pop LA

    2016-06-01

    Full Text Available Laura A Pop,1,* Valentina Pileczki,1,2,* Roxana M Cojocneanu-Petric,1 Bogdan Petrut,3,4 Cornelia Braicu,1 Ancuta M Jurj,1 Rares Buiga,5 Patriciu Achimas-Cadariu,6,7 Ioana Berindan-Neagoe1,8 1The Research Center for Functional Genomics, Biomedicine and Translational Medicine, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania; 2Department of Analytical Chemistry, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania; 3Department of Surgery II – Urology, The Oncology Institute “Prof Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania; 4Department of Urology, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania; 5Department of Pathology, The Oncology Institute “Prof. Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania; 6Department of Surgery, The Oncology Institute “Prof Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania; 7Department of Surgical Oncology and Gynecological Oncology, Iuliu Haţieganu University of Medicine and Pharmacy, 8Department of Functional Genomics and Experimental Pathology, The Oncology Institute “Prof Dr Ion Chiricuţă”, Cluj-Napoca, Cluj, Romania *These authors contributed equally to this work Background: Sample processing is a crucial step for all types of genomic studies. A major challenge for researchers is to understand and predict how RNA quality affects the identification of transcriptional differences (by introducing either false-positive or false-negative errors. Nanotechnologies help improve the quality and quantity control for gene expression studies. Patients and methods: The study was performed on 14 tumor and matched normal pairs of tissue from patients with bladder urothelial carcinomas. We assessed the RNA quantity by using the NanoDrop spectrophotometer and the quality by nano-microfluidic capillary electrophoresis technology provided by Agilent 2100 Bioanalyzer. We evaluated the amplification status of three

  10. A Bone Sample Containing a Bone Graft Substitute Analyzed by Correlating Density Information Obtained by X-ray Micro Tomography with Compositional Information Obtained by Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Johann Charwat-Pessler

    2015-06-01

    Full Text Available The ability of bone graft substitutes to promote new bone formation has been increasingly used in the medical field to repair skeletal defects or to replace missing bone in a broad range of applications in dentistry and orthopedics. A common way to assess such materials is via micro computed tomography (µ-CT, through the density information content provided by the absorption of X-rays. Information on the chemical composition of a material can be obtained via Raman spectroscopy. By investigating a bone sample from miniature pigs containing the bone graft substitute Bio Oss®, we pursued the target of assessing to what extent the density information gained by µ-CT imaging matches the chemical information content provided by Raman spectroscopic imaging. Raman images and Raman correlation maps of the investigated sample were used in order to generate a Raman based segmented image by means of an agglomerative, hierarchical cluster analysis. The resulting segments, showing chemically related areas, were subsequently compared with the µ-CT image by means of a one-way ANOVA. We found out that to a certain extent typical gray-level values (and the related histograms in the µ-CT image can be reliably related to specific segments within the image resulting from the cluster analysis.

  11. A simple method for obtaining transferrins from human plasma and porcine serum: preparations and properties.

    Science.gov (United States)

    Wu, Lin; Wu, Jinhui; Zhang, Jian; Zhou, Yuanyuan; Ren, Guoyan; Hu, Yiqiao

    2008-05-01

    A simple method was described for the purification of serum transferrin (Tf) from human plasma and porcine serum with relative high yield and purity. The properties including purity, integrity, immunoreactivity and the receptor-binding ability of the proteins were studied by several assays, comprising spectrometry, SDS-PAGE, HPLC, Western blotting, urea electrophoresis, mass spectrometry and cytometry. Analysis from all the different aspects manifested that the proteins were of high purity. The two kinds of Tfs appeared to be iron-saturated as confirmed by their absorbance spectra and urea-PAGE mobility. The specific spectra of absorption of the two Tfs were both at around 465 nm. The relative molecular weights of human Tf (hTf) and porcine Tf (pTf) were determined by SDS-PAGE and further identified by MAIDI-TOF mass spectrometry with a result of 79,707 and 79,258, respectively. Immunoblotting assay showed that pTf could react with the anti-human Tf monoclonal antibody with a less level compared to hTf. FACS assays of their binding activities to Tf receptor-positive cell (K562 cell line) indicated that pTf could be recognized by the hTf receptor and internalized into cells, with a slightly less efficacy than hTf. All special property studies demonstrated that pTf was similar to hTf in physical and chemical characteristics, which gave a hint that pTf could substitute for hTf in some kinds of researches, such as using hTf as a carrier in drug targeting system.

  12. Fast determination of paraquat in plasma and urine samples by solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Gao, Lina; Liu, Junting; Wang, Chunyuan; Liu, Guojie; Niu, Xiaodong; Shu, Cuixia; Zhu, Juan

    2014-01-01

    A simple, sensitive and reliable gas chromatographic-mass spectrometric method (GC-MS) for quantifying paraquat concentration in biological samples has been developed, using ethyl paraquat as an internal standard. The method involved the procedures of sodium borohydride-nickel chloride (NaBH4-NiCl2) reduction and solid-phase microextraction (SPME) of the perhydrogenated products. GC-MS was used to identify and quantify the analytes in selected ion monitoring (SIM) mode. Under the optimal conditions, recoveries in plasma and urine samples were 94.00-99.85% and 95.00-100.34%, respectively. Excellent sample clean-up was observed and good linearities (r=0.9982 for plasma sample and 0.9987 for urine sample) were obtained in the range of 0.1-50μg/mL. The limits of detection (S/N=3) were 0.01μg/mL in plasma and urine samples. The intra-day precision was less than 8.43%, 4.19% (n=3), and inter-day precision was less than 10.90%, 10.49% (n=5) for plasma and urine samples, respectively. This method was successfully applied to the analysis of the biological samples collected from a victim who died as a result of ingestion of paraquat.

  13. Genotypic characterization of Staphylococcus aureus obtained from humans and bovine mastitis samples in India

    Directory of Open Access Journals (Sweden)

    K Prashanth

    2011-01-01

    Full Text Available Aim and Background: Staphylococcus aureus is a major human pathogen that also causes important infections in cattle and sheep. The present study aimed to test genetic diversity among strains of S. aureus isolated from cattle (n=34 and humans (n=22 by DNA typing. Materials and Methods: Fluorescent amplified fragment length polymorphism (FAFLP is the genotyping tool used in the study. The presence of the mecA and Panton-Valentine leukocidin (PVL genes among these strain groups was also checked. Results: A dendrogram deduced from FAFLP showed that all the strains clustered into 10 groups (A-J with a relative genetic divergence of less than 8%. Sixty-seven percent of the isolates from bovine sources clustered together in two clades (A and H, while another major cluster with 13 isolates (59% (Cluster G had all strains from a human host. The remaining strains from both the hosts clustered independently into smaller clusters with the exception of two strains of human origin, which clustered along with a bovine cluster. Thirteen strains belonging to cluster G were highly clonal. About 77% of strains obtained from human infections were methicillin-resistant S. aureus (MRSA, whereas only 29% of strains from bovine origin were MRSA. Only three strains from human origin showed PVL positive, while no strain from cattle had PVL genes. The complete absence of PVL genes in all the bovine strains in the study appears to be significant. Conclusions: FAFLP can be successfully applied to assess the genetic relationship of S. aureus isolates from different hosts. The study also provided the valuable epidemiological data on S. aureus from bovine sources in India, which is lacking.

  14. Design of a protocol for obtaining genomic DNA from saliva using mouthwash: Samples taken from patients with periodontal disease

    Science.gov (United States)

    Mendoza, Ángel Chávez; Volante, Beatriz Buentello; Hernández, María Esther Ocharán; Mendoza, Claudia Camelia Calzada; Pliego, Arturo Flores; Baptista Gonzalez, Héctor A.; Juárez, Higinio Estrada

    2016-01-01

    Background Obtaining high quality genomic DNA safely and economically is vital for diverse studies of large populations aimed at evaluating the role of genetic factors in susceptibility to disease. Aim This study was to test a protocol for the extraction of high quality genomic DNA from saliva samples obtained with mouthwash and taken from patients with periodontal disease. Methods Saliva samples were taken from 60 patients and then stored at room temperature. DNA extraction was carried out at distinct post-sampling times (10, 20 and 30 days). Evaluation of genomic DNA was performed with spectrophotometry, electrophoresis, and PCR genotyping and sequencing. Results The greatest concentration of DNA obtained was 352 μg at 10 days post-sampling, followed by 121.025 μg and 19.59 μg at 20 and 30 days, respectively. When determining the purity of DNA with the spectrophotometric ratio of 260/230, the relations of 1.20, 1.40 and 0.781 were obtained for 10, 20 and 30 days, respectively. In all samples, it was possible to amplify the product of 485 bp and the sequence of the amplicons showed 95% similarity to the reference sequence. Conclusion The present protocol represents an easy, safe and economical technique for obtaining high quality genomic DNA. PMID:27195211

  15. Characterization of Nanostructured NbSi2 Intermetallic Coatings Obtained by Plasma Spraying of Mechanically Alloyed Powders

    Science.gov (United States)

    Yazdani, Zohreh; Karimzadeh, Fathallah; Abbasi, Mohammad-Hasan

    2015-08-01

    Nanostructured NbSi2 powders plasma sprayed on to Ti-6Al-4V substrates were characterized in this research. After preparation of the nanostructured NbSi2 powders by mechanical alloying of an Nb-Si powder mixture, agglomeration was performed to obtain a particle size suitable for spraying. The agglomerated powders were then sprayed by atmospheric plasma spraying. Structural transformation of the powders and morphological and mechanical changes of the coatings were examined by use of x-ray diffraction analysis, scanning electron microscopy, energy dispersive spectroscopy, and microhardness testing. During milling, NbSi2 intermetallic with a grain size of approximately 15 nm was gradually formed. After plasma spraying, a coating of hardness 550 ± 8 HV with a uniform nanocrystalline structure, low oxide content, low porosity, and a good adhesion to the substrate was obtained. No phase change occurred after spraying and the NbSi2 compound remained nanostructured with a grain size of approximately 82 nm.

  16. LC-MS analysis of the plasma metabolome–a novel sample preparation strategy

    DEFF Research Database (Denmark)

    Skov, Kasper; Hadrup, Niels; Smedsgaard, Jørn

    2015-01-01

    of plasma samples: The first is protein precipitation; the second is protein precipitation followed by solid phase extraction with sub-fractionation into three sub-samples; a phospholipid, a lipid and a polar sub-fraction. Molecular feature extraction of the data files from LC-qTOF analysis of the samples......Blood plasma is a well-known body fluid often analyzed in studies on the effects of toxic compounds as physiological or chemical induced changes in the mammalian body are reflected in the plasma metabolome. Sample preparation prior to LC-MS based analysis of the plasma metabolome is a challenge...... as plasma contains compounds with very different properties. Besides, proteins, which usually are precipitated with organic solvent, phospholipids, are known to cause ion suppression in electrospray mass spectrometry. We have compared two different sample preparation techniques prior to LC-qTOF analysis...

  17. Controls to validate plasma samples for cell free DNA quantification

    DEFF Research Database (Denmark)

    Pallisgaard, Niels; Spindler, Karen-Lise Garm; Andersen, Rikke Fredslund;

    2015-01-01

    Recent research has focused on the utility of cell free DNA (cfDNA) in serum and plasma for clinical application, especially in oncology. The literature holds promise of cfDNA as a valuable tumour marker to be used for treatment selection, monitoring and follow-up. The results, however, are diver...

  18. Stable isotope dilution analysis of hydrologic samples by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Garbarino, J.R.; Taylor, H.E.

    1987-01-01

    Inductively coupled plasma mass spectrometry is employed in the determination of Ni, Cu, Sr, Cd, Ba, Ti, and Pb in nonsaline, natural water samples by stable isotope dilution analysis. Hydrologic samples were directly analyzed without any unusual pretreatment. Interference effects related to overlapping isobars, formation of metal oxide and multiply charged ions, and matrix composition were identified and suitable methods of correction evaluated. A comparability study snowed that single-element isotope dilution analysis was only marginally better than sequential multielement isotope dilution analysis. Accuracy and precision of the single-element method were determined on the basis of results obtained for standard reference materials. The instrumental technique was shown to be ideally suited for programs associated with certification of standard reference materials.

  19. ENO1 Protein Levels in the Tumor Tissues and Circulating Plasma Samples of Non-small Cell Lung Cancer Patients

    Directory of Open Access Journals (Sweden)

    Ying ZHANG

    2010-12-01

    Full Text Available Background and objective Proper tumor markers are useful to diagnosis, prognosis and treatment for lung cancer. The aim of this study is to examine the levels of alpha-enolase (ENO1 protein in the tumor tissues and peripheral plasma samples obtained from non-small cell lung cancer (NSCLC patients, and evaluate its potential clinical significance. Methods The ENO1 protein levels in the tumor tissues and corresponding normal tissues from 16 cases of lung squamous cell carcinoma were analyzed by Western blot. The ENO1 protein levels in the plasma samples from 42 healthy individuals, 34 patients with lung benign disease and 84 patients with NSCLC were measured by double antibody sandwich enzyme-linked immunosorbent assay. Results For 87.5% (14/16 of the patients with lung squamous cell carcinoma, the ENO1 protein level in the tumor tissues was higher than that in the corresponding normal lung tissues. The ENO1 protein level in the plasma of NSCLC patients was significantly higher than that in the plasma of healthy individuals (P=0.031 and patients with lung benign disease (P=0.019. Furthermore, the ENO1 protein level was significantly higher in the plasma of patients with lung adenocarcinoma than that of patients with lung squamous cell carcinoma. Conclusion The elevated levels of ENO1 protein in the tumor tissues and the plasma samples from NSCLC patients indicate ENO1 may be a candidate biomarker of lung cancer.

  20. Evidence for obtaining a second successive semen sample for intrauterine insemination in selected patients: results from 32 consecutive cases.

    Science.gov (United States)

    Ortiz, Alejandra; Ortiz, Rita; Soto, Evelyn; Hartmann, Jonathan; Manzur, Alejandro; Marconi, Marcelo

    2016-06-01

    The goal of this study was to compare the semen parameters of two successive samples obtained within an interval of less than 60 minutes from patients planning to undergo intrauterine insemination (IUI) whose first samples exhibited low semen quality. Thirty-two consecutive patients were enrolled in the study. On the day of IUI, the semen analysis of the samples initially presented by all patients met at least two of the following criteria: sperm concentration <5×10(6)/mL, total sperm count <10×10(6), progressive sperm motility (a+b) in the native sample <30%, and total motile sperm count (TMSC) <4×10(6). A successive semen sample was obtained no more than 60 minutes after the first sample. Compared to the first sample, the second exhibited significantly (p<0.05) improved sperm concentration, TMSC, progressive motility, and vitality. Regarding TMSC, the most critical parameter on the day of IUI, 23 patients (71.8%) improved it, while nine (28.2%) displayed poorer outcomes. In defined cases, requesting a second successive ejaculate on the day of insemination may result in a high percentage of cases in an improvement of the quality of the sample.

  1. XPS and GDOES Characterization of Porous Coating Enriched with Copper and Calcium Obtained on Tantalum via Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Krzysztof Rokosz

    2016-01-01

    Full Text Available XPS and GDOES characterizations of porous coatings on tantalum after Plasma Electrolytic Oxidation (PEO at 450 V for 3 minutes in electrolyte containing concentrated (85% phosphoric acid with calcium nitrate and copper (II nitrate are described. Based on the obtained data, it may be concluded that the PEO coating consists of tantalum (Ta5+, calcium (Ca2+, copper (Cu2+  and Cu+, and phosphates (PO43-. It has to be pointed out that copper and calcium are distributed throughout the volume. The authors also propose a new model of PEO, based on the derivative of GDOES signals with sputtering time.

  2. Effects of blood sample handling procedures on measurable inflammatory markers in plasma, serum and dried blood spot samples

    DEFF Research Database (Denmark)

    Skogstrand, K.; Thorsen, P.; Vogel, I.

    2008-01-01

    of whole blood samples at low temperatures and rapid isolation of plasma and serum. Effects of different handling procedures for all markers studied are given. DBSS proved to be a robust and convenient way to handle samples for immunoassay analysis of inflammatory markers in whole blood Udgivelsesdato......The interests in monitoring inflammation by immunoassay determination of blood inflammatory markers call for information on the stability of these markers in relation to the handling of blood samples. The increasing use of stored biobank samples for such ventures that may have been collected...... and stored for other purposes, justifies the study hereof. Blood samples were stored for 0, 4, 24, and 48 h at 4 degrees C, room temperature (RT), and at 35 degrees C, respectively, before they were separated into serum or plasma and frozen. Dried blood spot samples (DBSS) were stored for 0, 1, 2, 3, 7...

  3. New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Montaser, A.

    1992-01-01

    New high temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. Emphasis was placed on atmospheric pressure He inductively coupled plasmas (ICP) suitable for atomization, excitation, and ionization of elements; simulation and computer modeling of plasma sources with potential for use in spectrochemical analysis; spectroscopic imaging and diagnostic studies of high temperature plasmas, particularly He ICP discharges; and development of new, low-cost sample introduction systems, and examination of techniques for probing the aerosols over a wide range. Refs., 14 figs. (DLC)

  4. Accurate and precise plasma clearance measurement using four 99mTc-DTPA plasma samples over 4 h

    OpenAIRE

    Wanasundara, Surajith N.; Wesolowski, Michal J.; Barnfield, Mark C.; Waller, Michael L.; Murray, Anthony W.; Burniston, Maria T.; Babyn, Paul S.; Wesolowski, Carl A.

    2015-01-01

    Objectives Glomerular filtration rate can be measured as the plasma clearance (CL) of a glomerular filtration rate marker despite body fluid disturbances using numerous, prolonged time samples. We desire a simplified technique without compromised accuracy and precision. Materials and methods We compared CL values derived from two plasma concentration curve area methods – (a) biexponential fitting [CL (E2)] and (b) Tikhonov adaptively regularized gamma variate fitting [CL (Tk-GV)] – for 4 vers...

  5. The combined evidential value of autosomal and Y-chromosomal DNA profiles obtained from the same sample

    NARCIS (Netherlands)

    de Zoete, J.; Sjerps, M.; Meester, R.; Cator, E.

    2014-01-01

    When a Y-chromosomal and a (partial) autosomal DNA profile are obtained from one crime sample, and both profiles match the suspect's profiles, we would like to know the combined evidential value. To calculate the likelihood ratio of observing the autosomal and Y-chromosomal DNA profiles combined, we

  6. Evaluation of endoscopically obtained duodenal biopsy samples from cats and dogs in an adapter-modified Ussing chamber

    Science.gov (United States)

    DeBiasio, John V.; Suchodolski, Jan S.; Newman, Shelley; Musch, Mark W.; Steiner, Jörg M.

    2014-01-01

    This study was conducted to evaluate an adapter-modified Ussing chamber for assessment of transport physiology in endoscopically obtained duodenal biopsies from healthy cats and dogs, as well as dogs with chronic enteropathies. 17 duodenal biopsies from five cats and 51 duodenal biopsies from 13 dogs were obtained. Samples were transferred into an adapter-modified Ussing chamber and sequentially exposed to various absorbagogues and secretagogues. Overall, 78.6% of duodenal samples obtained from cats responded to at least one compound. In duodenal biopsies obtained from dogs, the rate of overall response ranged from 87.5% (healthy individuals; n = 8), to 63.6% (animals exhibiting clinical signs of gastrointestinal disease and histopathological unremarkable duodenum; n = 15), and 32.1% (animals exhibiting clinical signs of gastrointestinal diseases and moderate to severe histopathological lesions; n = 28). Detailed information regarding the magnitude and duration of the response are provided. The adapter-modified Ussing chamber enables investigation of the absorptive and secretory capacity of endoscopically obtained duodenal biopsies from cats and dogs and has the potential to become a valuable research tool. The response of samples was correlated with histopathological findings. PMID:24378587

  7. Differential proteomic analysis of virus-enriched fractions obtained from plasma pools of patients with dengue fever or severe dengue.

    Science.gov (United States)

    Fragnoud, Romain; Flamand, Marie; Reynier, Frederic; Buchy, Philippe; Duong, Vasna; Pachot, Alexandre; Paranhos-Baccala, Glaucia; Bedin, Frederic

    2015-11-14

    Dengue is the most widespread mosquito-borne viral disease of public health concern. In some patients, endothelial cell and platelet dysfunction lead to life-threatening hemorrhagic dengue fever or dengue shock syndrome. Prognostication of disease severity is urgently required to improve patient management. The pathogenesis of severe dengue has not been fully elucidated, and the role of host proteins associated with viral particles has received little exploration. The proteomes of virion-enriched fractions purified from plasma pools of patients with dengue fever or severe dengue were compared. Virions were purified by ultracentrifugation combined with a water-insoluble polyelectrolyte-based technique. Following in-gel hydrolysis, peptides were analyzed by nano-liquid chromatography coupled to ion trap mass spectrometry and identified using data libraries. Both dengue fever and severe dengue viral-enriched fractions contained identifiable viral envelope proteins and host cellular proteins. Canonical pathway analysis revealed the identified host proteins are mainly involved in the coagulation cascade, complement pathway or acute phase response signaling pathway. Some host proteins were over- or under-represented in plasma from patients with severe dengue compared to patients with dengue fever. ELISAs were used to validate differential expression of a selection of identified host proteins in individual plasma samples of patients with dengue fever compared to patients with severe dengue. Among 22 host proteins tested, two could differentiate between dengue fever and severe dengue in two independent cohorts (olfactomedin-4: area under the curve (AUC), 0.958; and platelet factor-4: AUC, 0.836). A novel technique of virion-enrichment from plasma has allowed to identify two host proteins that have prognostic value for classifying patients with acute dengue who are more likely to develop a severe dengue. The impact of these host proteins on pathogenicity and disease outcome

  8. Analysis of liquid samples using dried-droplet laser ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Do, Trong-Mui; Hsieh, Hui-Fang; Chang, Wei-Ciang [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Chang, E.-E. [Department of Biochemistry, Taipei Medical University, Taipei City, 11031 Taiwan (China); Wang, Chu-Fang, E-mail: cfwang@mx.nthu.edu.tw [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2011-08-15

    In this study we developed a dried-droplet method for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The proposed method provides accurate and precise results when building calibration curves and determining elements of interest in real liquid samples. After placing just 1 {mu}L of a liquid standard solution or a real sample onto the filter surface and then converting the solution into a very small, thin dry spot, the sample could be applied as an analytical subject for LA. To demonstrate the feasibility of this proposed method, we used LA-ICP-MS and conventional ICP-MS to determine the levels of 13 elements (Li, V, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Tl, and Pb) in five water samples. The correlation coefficients obtained from the various calibration curves ranged from 0.9920 ({sup 205}Tl) to 0.9998 ({sup 51}V), sufficient to allow the determination of a wide range of elements in the samples. We also investigated the effects of Methylene Blue (MB) and the NaCl concentration on the elemental analyses. MB could be used as an indicator during the ablation process; its presence in the samples only negligibly influenced the intensities of the signals of most of the tested elements. Notably, high NaCl contents led to signal suppression for some of the elements. In comparison with the established sample introduction by nebulization, our developed technique abrogates the need for time-consuming sample preparation and reduces the possibility of sample contamination.

  9. Synthesis and characterization of carbon fibers obtained through plasma techniques; Sintesis y caracterizacion de fibras de carbono obtenidas mediante tecnicas de plasma

    Energy Technology Data Exchange (ETDEWEB)

    Valdivia B, M

    2005-07-01

    The study of carbon, particularly the nano technology is a recent field, the one which has important implications in the science of new materials. It investigation is of great interest for industries producers of ceramic, metallurgy, electronic, energy storage, biomedicine, among others. The diverse application fields are a reason at national as international level, so that many works are focused in the production of nano fibers of carbon. The Thermal plasma applications laboratory (LAPT) of the National Institute of Nuclear Research (ININ), it is carrying out works about carbon nano technology. The present work has as purpose to carry out the synthesis and characterization of the carbon nano fibers which are obtained by electric arch of alternating current (CA) to high frequencies and by a plasma gun of non transferred arch, where are used hydrocarbons like benzene, methane, acetylene like carbon source and ferrocene, nickel, yttrium and cerium oxide like catalysts. For both techniques its were thought about a relationship among hydrocarbon-catalyst that it favored to the nano fibers production. The obtained product of each experiment outlined it was analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD), analysis with those were obtained pictures and diffraction graphs, which were observed to arrive to one conclusion on the operation conditions, same analysis with those were characterized the tests carried out according to the nano structures formation of carbon. (Author)

  10. Determination of trace elements in refined gold samples by inductively coupled plasma atomic emission spectrometry

    Directory of Open Access Journals (Sweden)

    Steharnik Mirjana

    2013-01-01

    Full Text Available This paper presents a method for determination the trace contents of silver, copper, iron, palladium, zinc and platinum in refined gold samples. Simultaneous inductively coupled plasma atomic emission spectrometer with radial torch position and cross flow nebulizer was used for determination. In order to compare the different calibration strategies, two sets of calibration standards were prepared. The first set was based on matrix matched calibration standards and the second was prepared without the addition of matrix material. Detection limits for matrix matching calibrations were higher for some elements than those without matrix matching. In addition, the internal standardization method was applied and experiments indicated that indium was the best option as internal standard. The obtained results for gold sample by matrix matching and matrix free calibrations were compared with the obtained results by standard addition method. The accuracy of the methods was tested performing recovery test. Recoveries for spiked sample were in the range of 90-115 %. The accuracy of the methods was also tested by analysis of certified reference material of high pure goldAuGHP1. The best results were achieved by matrix free calibration and standard addition method using indium as internal standard at wavelength of 230 nm. [Projekat Ministarstva nauke Republike Srbije, br. 34024: Development of Technologies for Recycling of Precious, Rare and Associated Metals from Solid Waste in Serbia to High Purity Products

  11. Separation and Determination of Methylnaltrexone in Human Plasma Samples After Oral Administration by HPLC Coupled with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    WANG An-bao; Joseph F. Foss; YUAN Chun-su; Joachim Osinski

    2005-01-01

    A high performance liquid chromatography(HPLC) method coupled with electrochemical detection and solid phase extraction is described for the separation and determination of methylnaltrexone(MNTX), a quaternary opioid antagonist, in human clinical plasma samples after oral administration. Linearity of the standard curve for MNTX was found in the range of 4.0_150 ng/mL and was statistically conformed. The correlation coefficient(r2) and calibration equation obtained from linear regression analysis are 0.9999 and Y=54.27X-0.22, where Y and X represent the peak area and concentration of MNTX, respectively. The detection limit of MNTX under the present experimental conditions is 2.0 ng/mL by estimating at a ratio of 3 of signal to noise. The mean recovery of MNTX in human plasma is higher than 97%. The analytical method was applied to the pharmacokinetic determination of MNTX after single dose oral administration. These data demonstrate that the change of MNTX plasma concentration versus time is obvious. MNTX level of plasma reaches to a plateau between 45 to 120 minutes and then falls slowly. The content of MNTX in plasma sample maintains at an obviously detectable level after twelve hours of oral administration. The pharmacokinetic parameters for a single dose of 19.2 mg/kg in plasma are cmax=206.42(±16.53) ng/mL and tmax=60 min.

  12. Evaluation of rock powdering methods to obtain fine-grained samples for CHEMIN, a combined XRD/XRF instrument

    Energy Technology Data Exchange (ETDEWEB)

    Chipera, S. J. (Steve J.); Vaniman, D. T. (David T.); Bish, D. L. (David L.); Sarrazin, P.; Feldman, S.; Blake, D.; Bearman, G. H. (Gregory H.); Bar-Cohen, Yoseph

    2004-01-01

    A miniature XRD/XRD (X-ray diffraction/X-ray fluorescence) instrument, CHEMIN, is currently being developed for definite mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed to enable remote XRD analysis is how best to obtain a representative sample powder for analysis. For powder XRD analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a two-dimensional detector as used in the CHEMIN instrument produces good results even with poorly prepared powder, the quality of the data improves and the time required for data collection is reduced if the sample is fine-grained and randomly oriented. A variety of methods have been proposed for XRD sample preparation. Chipera et al. presented grain size distributions and XRD reuslts from powders generated with an Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL. The USDC was shown to be an effective instrument for sampling rock to produce powder suitable for XRD. In this paper, they compare powder prepared using the USDC with powder obtained with a miniaturized rock crusher developed at JPL and with powder obtained with a rotary tungsten carbide bit to powders obtained from a laboratory bench-scale Retsch mill (provides benchmark mineralogical data). These comparisons will allow assessment of the suitability of these methods for analysis by an XRD/XRD instrument such as CHEMIN.

  13. Porous membrane ultrafiltration-A novel method for enrichment of the active compounds from micro-plasma samples

    Science.gov (United States)

    Liu, Qingshan; Yin, Xiaoying; Sha, Biying; You, Jingjing

    2014-10-01

    To enrich the active compounds from plasma samples, a novel and simple method has been developed using a porous membrane envelope based on the ultrafiltration technique combining with high-performance liquid chromatography. The ultrafiltration device is a sealed porous membrane envelope prepared with a polypropylene sheet to effectively separate the active small molecules and large biomolecules, and a sample carrier is held inside the envelope to load plasma samples. The enrichment of hyperoside and isoquercitrin from rat plasma was used as an example. Significant factors of this method, such as membrane types, the desorption solvent, and the desorption time were optimized for the ultrafiltration method. Under the optimal conditions, correlation coefficients of 0.999 and 0.998 were obtained for hyperoside and isoquercitrin, respectively, with a linear range between 0.5 and 100 μg/mL. The absolute extraction recoveries from 83.2% to 86.8% were achieved. The detection limits of the method for hyperoside and isoquercitrin were 0.22 and 0.20 μg/mL, respectively. Compared with protein precipitation, solid-phase extraction and commercial ultrafiltration membrane methods, our proposed method demonstrates lower detection limits and lower cost for extraction. Also, it consumes less plasma samples and is found to be applicable to biological samples.

  14. Liquid-based thin-layer cytology can be routinely used in samples obtained via fiberoptic bronchoscope.

    Science.gov (United States)

    Kobayashi, Yukihiro; Uehara, Takeshi; Ota, Hiroyoshi

    2011-01-01

    The aim of this study was to evaluate liquid-based preparations (LBP) as a replacement for conventional smears (CS) of bronchial brushing (BB) and transbronchial fine-needle aspiration (TBNA) samples obtained via fiberoptic bronchoscope. Bronchial brushing and TBNA samples were obtained from 62 and 33 patients by fiberoptic bronchoscopy, respectively. Liquid-based preparations were prepared from needle rinse after initial CS preparation. We compared cellularity, cell morphology, and background between the LBP and CS slides. Correspondence rates between LBP and CS diagnoses in the above 3 categories were 90.3% in the BB and 97.0% in the TBNA samples. If suspicious cases were regarded as malignant, correspondence rates reached 98.4 and 100%, respectively. Histological diagnoses by LBP were mostly the same as those by CS and by biopsy or operation samples. Morphologically, cells and nuclei were shrunk in the LBP; however, the shrinking was not severe enough to influence cytological diagnoses. Blood background and air-drying, which were observed on many of the CS slides, were not detected on the LBP slides. It is possible to use LBP for routine laboratory processing of BB and TBNA samples as a replacement for CS. Copyright © 2010 S. Karger AG, Basel.

  15. Effect of piperine on pharmacokinetics of sodium valproate in plasma samples of rats using gas chromatography-mass spectrometry method

    Directory of Open Access Journals (Sweden)

    Bushra Parveen

    2015-01-01

    Full Text Available Piperine (PIP is used as anticonvulsant in traditional Chinese medicine. Co-administration of low-dose sodium valproate with PIP has been regarded to have potential anticonvulsant activity. Aim: This study was intended to investigate the effect of PIP on the pharmacokinetics of sodium valproate (SVP in the plasma samples of rats using gas chromatography-mass spectrometry (GC-MS method. Materials and Methods: The plasma samples obtained after oral administration of SVP, 150 mg/kg and SVP, 150 mg/kg + PIP, and 5 mg/kg to male Wistar rats were used to quantify the concentrations in plasma using GC-MS method. Results: A simple and accurate method developed in-house was applied for the analysis of plasma samples of Wistar rats after oral administration of SVP and PIP + sodium valproate, respectively. The pharmacokinetic parameters reported 14.8-fold increase in plasma concentration (maximum observed concentration in the concentration-time profile, 4.6-fold increase in area under the curve and slightly prolonged time to reach that concentration (1 h of SVP in presence of PIP. Conclusion: The study reaffirms the bioenhancing effect of PIP suggesting possibility of dose reduction of SVP while co-adminstering with PIP.

  16. Impact of hemolysis during sample collection: how different is drug concentration in hemolyzed plasma from that of normal plasma?

    Science.gov (United States)

    Tan, Aimin; Gagné, Sébastien; Lévesque, Isabelle A; Lachance, Sylvain; Boudreau, Nadine; Lévesque, Ann

    2012-07-15

    Hemolysis is a common phenomenon in clinical studies. Despite the growing interest in hemolysis matrix effect, how hemolysis impacts the representability of hemolyzed plasma samples was rarely evaluated. The purpose of this research is to perform such an evaluation by theoretical consideration and experiment. A formula for estimating the impact is proposed, which includes the degree of hemolysis and the drug's red blood cell (RBC): plasma concentration ratio. The impact of hemolysis on the representability of hemolyzed plasma samples is compound-dependant. Given the same degree of hemolysis, the stronger a drug binds to RBCs, the more significant the impact of hemolysis. For a drug with high affinity to RBCs, the results of hemolyzed plasma samples may not be useful even though they are accurate. There is an overall agreement between theoretical predication and experimental results. Among the ten different drug compounds tested, only methazolamide, which binds strongly to RBCs, showed significant change in plasma concentration due to hemolysis. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Surveillance cultures of samples obtained from biopsy channels and automated endoscope reprocessors after high-level disinfection of gastrointestinal endoscopes

    OpenAIRE

    Chiu King-Wah; Tsai Ming-Chao; Wu Keng-Liang; Chiu Yi-Chun; Lin Ming-Tzung; Hu Tsung-Hui

    2012-01-01

    Abstract Background The instrument channels of gastrointestinal (GI) endoscopes may be heavily contaminated with bacteria even after high-level disinfection (HLD). The British Society of Gastroenterology guidelines emphasize the benefits of manually brushing endoscope channels and using automated endoscope reprocessors (AERs) for disinfecting endoscopes. In this study, we aimed to assess the effectiveness of decontamination using reprocessors after HLD by comparing the cultured samples obtain...

  18. Proteomic biomarker discovery in 1000 human plasma samples with mass spectrometry

    DEFF Research Database (Denmark)

    Cominetti, Ornella; Núñez Galindo, Antonio; Corthésy, John

    2016-01-01

    the quality of the MS data and provided descriptive statistics. The data set was interrogated for proteins with most stable expression levels in that set of plasma samples. We evaluated standard clinical variables that typically impact forthcoming results and assessed body mass index-associated and gender......-specific proteins at two time points. We demonstrate that analyzing a large number of human plasma samples for biomarker discovery with MS using isobaric tagging is feasible, providing robust and consistent biological results....

  19. Arterial blood gas analysis of samples directly obtained beyond cerebral arterial occlusion during endovascular procedures predicts clinical outcome.

    Science.gov (United States)

    Flores, Alan; Sargento-Freitas, Joao; Pagola, Jorge; Rodriguez-Luna, David; Piñeiro, Socorro; Maisterra, Olga; Rubiera, Marta; Montaner, Joan; Alvarez-Sabin, Jose; Molina, Carlos; Ribo, Marc

    2013-04-01

    Real-time intra-procedure information about ischemic brain damage degree may help physicians in taking decisions about pursuing or not recanalization efforts. We studied gasometric parameters of blood samples drawn through microcatheter in 16 stroke patients who received endovascular reperfusion procedures. After crossing the clot with microcatheter, blood sample was obtained from the middle cerebral artery (MCA) segment distal to occlusion (PostOcc); another sample was obtained from carotid artery (PreOcc). An arterial blood gas (ABG) study was immediately performed. We defined clinical improvement as National Institutes of Health Stroke Scale (NIHSS) decrease of ≥4. The ABG analysis showed differences between PreOcc and PostOcc blood samples in mean oxygen partial pressure (Pre-PaO2: 78.9 ± 16 .3 vs. 73.9 ± 14 .9 mmHg; P  70 mmHg that better predicted further clinical improvement. Patients with Post-PaO2 > 70 mmHg had higher chances of clinical improvement (81.8% vs. 0%; P = .002) and lower disability (median mRS:3 vs. 6; P= .024). In the logistic regression the only independent predictor of clinical improvement was Post-PaO2 > 70 (OR: 5.21 95% CI: 1.38-67.24; P = .013). Direct local blood sampling from ischemic brain is feasible during endovascular procedures in acute stroke patients. A gradient in oxygenation parameters was demonstrated between pre- and post-occlusion blood samples. ABG information may be used to predict clinical outcome and help in decision making in the angio-suite. Copyright © 2011 by the American Society of Neuroimaging.

  20. Utility of the microculture method for Leishmania detection in non-invasive samples obtained from a blood bank.

    Science.gov (United States)

    Ates, Sezen Canim; Bagirova, Malahat; Allahverdiyev, Adil M; Kocazeybek, Bekir; Kosan, Erdogan

    2013-10-01

    In recent years, the role of donor blood has taken an important place in epidemiology of Leishmaniasis. According to the WHO, the numbers of patients considered as symptomatic are only 5-20% of individuals with asymptomatic leishmaniasis. In this study for detection of Leishmania infection in donor blood samples, 343 samples from the Capa Red Crescent Blood Center were obtained and primarily analyzed by microscopic and serological methods. Subsequently, the traditional culture (NNN), Immuno-chromatographic test (ICT) and Polymerase Chain Reaction (PCR) methods were applied to 21 samples which of them were found positive with at least one method. Buffy coat (BC) samples from 343 blood donors were analyzed: 15 (4.3%) were positive by a microculture method (MCM); and 4 (1.1%) by smear. The sera of these 343 samples included 9 (2.6%) determined positive by ELISA and 7 (2%) positive by IFAT. Thus, 21 of (6.1%) the 343 subjects studied by smear, MCM, IFAT and ELISA techniques were identified as positive for leishmaniasis at least one of the techniques and the sensitivity assessed. According to our data, the sensitivity of the methods are identified as MCM (71%), smear (19%), IFAT (33%), ELISA (42%), NNN (4%), PCR (14%) and ICT (4%). Thus, with this study for the first time, the sensitivity of a MCM was examined in blood donors by comparing MCM with the methods used in the diagnosis of leishmaniasis. As a result, MCM was found the most sensitive method for detection of Leishmania parasites in samples obtained from a blood bank. In addition, the presence of Leishmania parasites was detected in donor bloods in Istanbul, a non-endemic region of Turkey, and these results is a vital importance for the health of blood recipients.

  1. Spark Plasma Sintered Si3N4/TiN Nanocomposites Obtained by a Colloidal Processing Route

    Directory of Open Access Journals (Sweden)

    L. A. Díaz

    2016-01-01

    Full Text Available Ceramic Si3N4/TiN (22 vol% nanocomposites have been obtained by Spark Plasma Sintering (SPS. Our colloidal processing route allows obtaining dispersed nanoparticles of TiN smaller than 50 nm avoiding the presence of agglomerates. The nanostructured starting powders were obtained by using a colloidal method where commercial Si3N4 submicrometer particles were coated with anatase TiO2 nanocrystals. A later nitridation process led to the formation of TiN nanoparticles on the surface of Si3N4. A second set of powders was prepared by doping the above defined powders with yttrium and aluminium precursors using also a colloidal method as sources of alumina and yttria. After thermal nitridation and SPS treatment, it has been found that the addition of oxides dopants improves the mechanical performance (KIC, σf but increases the electrical resistivity and significantly reduces the hardness. This is due to the formation of a continuous insulating glassy phase that totally envelops the conductive TiN nanoparticles, avoiding the percolative contact between them. The combination of colloidal processing route and SPS allows the designing of tailor-made free glassy phase Si3N4/TiN nanocomposites with controlled microstructure. The microstructural features and the thermoelectrical and mechanical properties of both kinds of dense SPSed compacts are discussed in this work.

  2. [Results obtained using de "Meckrognost Harnstoff" strip method in estimating plasma urea concentrations in dogs (author's transl)].

    Science.gov (United States)

    de Bruyne, J J

    1977-09-01

    The "Merckognost Harntoff" strip method described in a previous paper was recently modified by the manufactures. An important alterations consisted in the method by which samples were applied to the strips, viz. using micropipetters rather than by dipping. In view of the findings in the comparative study reported, the results obtained on dipping are regarded as superior, the method also being easier to handle. However, the prescribed correction factor should be used.

  3. [A Large Number of Circulating Tumor Cells(CTCs)Can Be Isolated from Samples Obtained by Using Leukapheresis Procedures].

    Science.gov (United States)

    Soya, Ryoko; Taguchi, Jyunichi; Nagakawa, Yuichi; Takahashi, Osamu; Sandoh, Norimasa; Hosokawa, Yuichi; Kasuya, Kazuhiko; Umeda, Naoki; Okamoto, Masato; Tsujitani, Shunichi; Tsuchida, Akihiko

    2015-09-01

    We hypothesized that a large number of circulating tumor cells(CTCs)may be isolated from samples obtained by using the leukapheresis procedures that are utilized to collect peripheral blood mononuclear cells for dendritic cell vaccine therapy. We utilized the CellSearch System to determine the number of CTCs in samples obtained by using leukapheresis in 7 patients with colorectal cancer, 5 patients with breast cancer, and 3 patients with gastric cancer. In all patients, a large number of CTCs were isolated. The mean number of CTCs per tumor was 17.1(range 10-34)in colorectal cancer, 10.0(range 2-27)in breast cancer, and 24.0(range 2-42)in gastric cancer. We succeeded in culturing the isolated CTCs from 7 patients with colorectal cancer, 5 patients with breast cancer, and 3 patients with gastric cancer. In conclusion, compared to conventional methods, a large number of CTCs can be obtained by using leukapheresis procedures. The molecular analyses of the CTCs isolated by using this method should be promising in the development of personalized cancer treatments.

  4. Analysis of whole blood samples with low gas flow inductively coupled plasma-optical emission spectrometry.

    Science.gov (United States)

    Nowak, Sascha; Künnemeyer, Jens; Terborg, Lydia; Trümpler, Stefan; Günsel, Andreas; Wiesmüller, Gerhard A; Karst, Uwe; Buscher, Wolfgang

    2015-01-01

    Low gas flow ICP-OES with a total argon consumption below 0.7 L/min is introduced for the analysis of trace elements in blood samples to investigate the influence of samples containing an organic solvent in a demanding matrix on the performance of this plasma for the first time. Therefore, gadolinium was determined in human plasma samples and mercury in red blood cells, human plasma, and precipitated plasma protein fraction. Limits of detection (LOD) were determined to be in the low microgram per liter range for the analytes and the accuracy of the method was assessed by comparison with a conventional Fassel-type torch-based ICP-OES. It was proven that the low gas flow ICP-OES leads to comparable results with the instrument based on the Fassel-type torch.

  5. Mechanical Properties of Double-Layer and Graded Composite Coatings of YSZ Obtained by Atmospheric Plasma Spraying

    Science.gov (United States)

    Carpio, Pablo; Rayón, Emilio; Salvador, María Dolores; Lusvarghi, Luca; Sánchez, Enrique

    2016-04-01

    Double-layer and graded composite coatings of yttria-stabilized zirconia were sprayed on metallic substrates by atmospheric plasma spray. The coating architecture was built up by combining two different feedstocks: one micro- and one nanostructured. Microstructural features and mechanical properties (hardness and elastic modulus) of the coatings were determined by FE-SEM microscopy and nanoindentation technique, respectively. Additional adherence and scratch tests were carried out in order to assess the failure mechanisms occurring between the layers comprising the composites. Microstructural inspection of the coatings confirms the two-zone microstructure. This bimodal microstructure which is exclusive of the layer obtained from the nanostructured feedstock negatively affects the mechanical properties of the whole composite. Nanoindentation tests suitably reproduce the evolution of mechanical properties through coatings thickness on the basis of the position and/or amount of nanostructured feedstock used in the depositing layer. Adhesion and scratch tests show the negative effect on the coating adhesion of layer obtained from the nanostructured feedstock when this layer is deposited on the bond coat. Thus, the poor integrity of this layer results in lower normal stresses required to delaminate the coating in the adhesion test as well as minor critical load registered by using the scratch test.

  6. Microscopical characterization of {alpha}{double_prime}Fe{sub 16}N{sub 2} obtained by plasma assisted processes

    Energy Technology Data Exchange (ETDEWEB)

    Hinojosa, G.; Oseguera, J.; Salas, O.; Schabes-Retchkiman, P.S. [ITESM-CEM, Mexico City (Mexico)

    1996-01-01

    Nitriding of iron and carbon steels enhances their mechanical and tribological properties. The origin of the improvement arises from the formation of a nitride compound surface layer, and a diffusion zone f nitrogen interstitially dissolved in ferrite. The top layers may be composed of {var_epsilon} and {gamma}{prime} (carbo)nitrides. The solubility of nitrogen in the {alpha}-Fe (ferrite) decreases with temperature. If a nitrided piece is slowly cooled, precipitation of the metastable nitride {alpha}{double_prime} in the ferritic matrix usually precedes the formation of the more stable phase {gamma}{prime}. However, when the piece is quenched, formation of nitrogen tetragonal martensite {alpha}{prime} is observed instead. After a tempering process, this martensite leads to the precipitation of the {alpha}{double_prime} phase coherent with the ferrite. Further aging or aging of the {alpha}{double_prime} obtained from slow cooling leads to the stable precipitate {gamma}{prime}. These transformations are accompanied of hardness changes. The aim of this work is to present the optical microscopy, HREM and TEM characterization of the {alpha}{double_prime} precipitate, obtained in plasma-nitrided iron, and relate the hardness profile after aging with the transformation of this precipitate.

  7. Tissue Microarray Technology for Molecular Applications: Investigation of Cross-Contamination between Tissue Samples Obtained from the Same Punching Device.

    Science.gov (United States)

    Vassella, Erik; Galván, José A; Zlobec, Inti

    2015-04-02

    Tissue microarray (TMA) technology allows rapid visualization of molecular markers by immunohistochemistry and in situ hybridization. In addition, TMA instrumentation has the potential to assist in other applications: punches taken from donor blocks can be placed directly into tubes and used for nucleic acid analysis by PCR approaches. However, the question of possible cross-contamination between samples punched with the same device has frequently been raised but never addressed. Two experiments were performed. (1) A block from mycobacterium tuberculosis (TB) positive tissue and a second from an uninfected patient were aligned side-by-side in an automated tissue microarrayer. Four 0.6 mm punches were cored from each sample and placed inside their corresponding tube. Between coring of each donor block, a mechanical cleaning step was performed by insertion of the puncher into a paraffin block. This sequence of coring and cleaning was repeated three times, alternating between positive and negative blocks. A fragment from the 6110 insertion sequence specific for mycobacterium tuberculosis was analyzed; (2) Four 0.6 mm punches were cored from three KRAS mutated colorectal cancer blocks, alternating with three different wild-type tissues using the same TMA instrument (sequence of coring: G12D, WT, G12V, WT, G13D and WT). Mechanical cleaning of the device between each donor block was made. Mutation analysis by pyrosequencing was carried out. This sequence of coring was repeated manually without any cleaning step between blocks. In both analyses, all alternating samples showed the expected result (samples 1, 3 and 5: positive or mutated, samples 2, 4 and 6: negative or wild-type). Similar results were obtained without cleaning step. These findings suggest that no cross-contamination of tissue samples occurs when donor blocks are punched using the same device, however a cleaning step is nonetheless recommended. Our result supports the use of TMA technology as an accessory

  8. Temperature-Accelerated Sampling and Amplified Collective Motion with Adiabatic Reweighting to Obtain Canonical Distributions and Ensemble Averages.

    Science.gov (United States)

    Hu, Yue; Hong, Wei; Shi, Yunyu; Liu, Haiyan

    2012-10-09

    In molecular simulations, accelerated sampling can be achieved efficiently by raising the temperature of a small number of coordinates. For collective coordinates, the temperature-accelerated molecular dynamics method or TAMD has been previously proposed, in which the system is extended by introducing virtual variables that are coupled to these coordinates and simulated at higher temperatures (Maragliano, L.; Vanden-Eijnden, E. Chem. Phys. Lett.2005, 426, 168-175). In such accelerated simulations, steady state or equilibrium distributions may exist but deviate from the canonical Boltzmann one. We show that by assuming adiabatic decoupling between the subsystems simulated at different temperatures, correct canonical distributions and ensemble averages can be obtained through reweighting. The method makes use of the low-dimensional free energy surfaces that are estimated as Gaussian mixture probability densities through maximum likelihood and expectation maximization. Previously, we proposed the amplified collective motion method or ACM. The method employs the coarse-grained elastic network model or ANM to extract collective coordinates for accelerated sampling. Here, we combine the ideas of ACM and of TAMD to develop a general technique that can achieve canonical sampling through reweighting under the adiabatic approximation. To test the validity and accuracy of adiabatic reweighting, first we consider a single n-butane molecule in a canonical stochastic heat bath. Then, we use explicitly solvated alanine dipeptide and GB1 peptide as model systems to demonstrate the proposed approaches. With alanine dipeptide, it is shown that sampling can be accelerated by more than an order of magnitude with TAMD while correct distributions and canonical ensemble averages can be recovered, necessarily through adiabatic reweighting. For the GB1 peptide, the conformational distribution sampled by ACM-TAMD, after adiabatic reweighting, suggested that a normal simulation suffered

  9. Tissue Microarray Technology for Molecular Applications: Investigation of Cross-Contamination between Tissue Samples Obtained from the Same Punching Device

    Directory of Open Access Journals (Sweden)

    Erik Vassella

    2015-04-01

    Full Text Available Background: Tissue microarray (TMA technology allows rapid visualization of molecular markers by immunohistochemistry and in situ hybridization. In addition, TMA instrumentation has the potential to assist in other applications: punches taken from donor blocks can be placed directly into tubes and used for nucleic acid analysis by PCR approaches. However, the question of possible cross-contamination between samples punched with the same device has frequently been raised but never addressed. Methods: Two experiments were performed. (1 A block from mycobacterium tuberculosis (TB positive tissue and a second from an uninfected patient were aligned side-by-side in an automated tissue microarrayer. Four 0.6 mm punches were cored from each sample and placed inside their corresponding tube. Between coring of each donor block, a mechanical cleaning step was performed by insertion of the puncher into a paraffin block. This sequence of coring and cleaning was repeated three times, alternating between positive and negative blocks. A fragment from the 6110 insertion sequence specific for mycobacterium tuberculosis was analyzed; (2 Four 0.6 mm punches were cored from three KRAS mutated colorectal cancer blocks, alternating with three different wild-type tissues using the same TMA instrument (sequence of coring: G12D, WT, G12V, WT, G13D and WT. Mechanical cleaning of the device between each donor block was made. Mutation analysis by pyrosequencing was carried out. This sequence of coring was repeated manually without any cleaning step between blocks. Results/Discussion: In both analyses, all alternating samples showed the expected result (samples 1, 3 and 5: positive or mutated, samples 2, 4 and 6: negative or wild-type. Similar results were obtained without cleaning step. These findings suggest that no cross-contamination of tissue samples occurs when donor blocks are punched using the same device, however a cleaning step is nonetheless recommended. Our

  10. Correlation of lithium levels between drinking water obtained from different sources and scalp hair samples of adult male subjects.

    Science.gov (United States)

    Baloch, Shahnawaz; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Talpur, Farah Naz; Arain, Muhammad Balal

    2016-10-18

    There is some evidence that natural levels of lithium (Li) in drinking water may have a protective effect on neurological health. In present study, we evaluate the Li levels in drinking water of different origin and bottled mineral water. To evaluate the association between lithium levels in drinking water with human health, the scalp hair samples of male subjects (25-45 years) consumed drinking water obtained from ground water (GW), municipal treated water (MTW) and bottled mineral water (BMW) from rural and urban areas of Sindh, Pakistan were selected. The water samples were pre-concentrated five to tenfold at 60 °C using temperature-controlled electric hot plate. While scalp hair samples were oxidized by acid in a microwave oven, prior to determined by flame atomic absorption spectrometry. The Li content in different types of drinking water, GW, MTW and BMW was found in the range of 5.12-22.6, 4.2-16.7 and 0.0-16.3 µg/L, respectively. It was observed that Li concentration in the scalp hair samples of adult males consuming ground water was found to be higher, ranged as 292-393 μg/kg, than those who are drinking municipal treated and bottle mineral water (212-268 and 145-208 μg/kg), respectively.

  11. Characteristics of ionospheric plasma drifts as obtained from Doppler ionosonde measurements at magnetic equator over Indian sector

    Science.gov (United States)

    Samireddipalle, Sripathi; Banola, Sridhar; Singh, Ram

    2016-07-01

    We present equatorial plasma drifts over Tirunelveli (8.73°N, 77.70°E; Dip 0.5°N), an equatorial site over Indian region using Doppler interferometry technique of Canadian Advanced Digital Ionosonde (CADI) system. In the Doppler interferometry technique, it is possible to infer three dimensional bulk motion of the scatterers as reflected from the ionosphere at selected frequencies using spaced receivers arranged in mag. east-west, north-south directions. Spectral phases and amplitudes are calculated using FFT to identify the Doppler frequencies and their drifts. This technique produces reliable drifts when sharp refractive index gradients exists which produces higher scattering sources. The vertical drifts so obtained are compared with same drifts from Digisonde at Trivandrum. After having compared with Digisonde drifts, we studied the temporal and seasonal variability of these drifts during quiet periods for the year 2012. It is seen that vertical drifts exhibited equinoctial maximum in the Pre-Reversal-Enhancement (PRE) followed by winter and summer respectively. A comparison of these vertical drifts is made with drifts obtained from (a) virtual height measured at 4 MHz and (b) Fejer drift model. The comparison suggests that Doppler vertical drifts are relatively higher as compared to the drifts obtained from model and virtual height. However, the correlation seems to be good around evening PRE times. The zonal drifts, on the other hand, showed westward drifts during daytime with mean drifts of ~250 m/s, while they are eastward during nighttime with mean drifts of ~150 m/s. These drifts seems to be higher as compared to zonal drifts obtained in the South American sector. However, the zonal drifts so obtained showed good correlation with Equatorial Electrojet (EEJ) strength suggesting zonal drifts are influenced by E region drifts during daytime in agreement with Woodman et al., 2013 paper. The magnitude of these drifts are comparable to other independent

  12. The effect of sample size on fresh plasma thromboplastin ISI determination

    DEFF Research Database (Denmark)

    Poller, L; Van Den Besselaar, A M; Jespersen, J;

    1999-01-01

    The possibility of reduction of numbers of fresh coumarin and normal plasmas has been studied in a multicentre manual prothrombin (PT) calibration of high international sensitivity index (ISI) rabbit and low ISI human reference thromboplastins at 14 laboratories. The number of calibrant plasmas...... was reduced progressively by a computer program which generated random numbers to provide 1000 different selections for each reduced sample at each participant laboratory. Results were compared with those of the full set of 20 normal and 60 coumarin plasma calibrations. With the human reagent, 20 coumarins...... and seven normals still achieved the W.H.O. precision limit (3% CV of the slope), but with the rabbit reagent reduction coumarins with 17 normal plasmas led to unacceptable CV. Little reduction of numbers from the full set of 80 fresh plasmas appears advisable. For maximum confidence, when calibrating...

  13. Simulation of rarefied low pressure RF plasma flow around the sample

    Science.gov (United States)

    Zheltukhin, V. S.; Shemakhin, A. Yu

    2017-01-01

    The paper describes a mathematical model of the flow of radio frequency plasma at low pressure. The hybrid mathematical model includes the Boltzmann equation for the neutral component of the RF plasma, the continuity and the thermal equations for the charged component. Initial and boundary conditions for the corresponding equations are described. The electron temperature in the calculations is 1-4 eV, atoms temperature in the plasma clot is (3-4) • 103 K, in the plasma jet is (3.2-10) • 102 K, the degree of ionization is 10-7-10-5, electron density is 1015-1019 m-3. For calculations plasma parameters is developed soft package on C++ program language, that uses the OpenFOAM library package. Simulations for the vacuum chamber in the presence of a sample and the free jet flow were carried out.

  14. Statistical evaluation of fatty acid profile and cholesterol content in fish (common carp) lipids obtained by different sample preparation procedures.

    Science.gov (United States)

    Spiric, Aurelija; Trbovic, Dejana; Vranic, Danijela; Djinovic, Jasna; Petronijevic, Radivoj; Matekalo-Sverak, Vesna

    2010-07-01

    the second principal component (PC2) is recorded by C18:3 n-3, and C20:3 n-6, being present in a higher amount in the samples treated by the modified Soxhlet extraction, while C22:5 n-3, C20:3 n-3, C22:1 and C20:4, C16 and C18 negatively influence the score values of the PC2, showing significantly increased level in the samples treated by ASE method. Hotelling's paired T-square test used on the first three principal components for confirmation of differences in individual fatty acid content obtained by ASE and Soxhlet method in carp muscle showed statistically significant difference between these two data sets (T(2)=161.308, p<0.001).

  15. Separation of proteins from human plasma by sample displacement chromatography in hydrophobic interaction mode

    OpenAIRE

    Josic, Djuro; Breen, Lucas; Clifton, James; Gajdosik, Martina Srajer; Gaso-Sokac, Dajana; Rucevic, Marijana; Müller, Egbert

    2012-01-01

    Sample displacement chromatography (SDC) in reversed-phase and ion-exchange modes was introduced approximately twenty years ago. This method was first used for the preparative purification of peptides and proteins. Recently, SDC in ion-exchange mode was also successfully used for enrichment of low abundance proteins from human plasma. In this paper, the use of SDC for the separation of plasma proteins in hydrophobic interaction mode is demonstrated. By use of two or more columns coupled in se...

  16. Trace Elements Analysis of Geological Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper describes recent work applying a taser ablation system (LSX-200) hyphenated with POEMS Ⅲ inductively coupled plasma mass spectrometry (LA-ICP-MS) for the in situ analysis of 22 trace elements of solid geological materials. It demonstrates the potential of LA-ICP-MS for the determination of geochemically important trace and ultra-trace elements following XRF routine sample preparation. Signal drift, difference in transport efficiency and sampling yield are well corrected with NIST SRM 612 as external calibration standard and Ca as internal standard. The obtained results agree to the recommended values with relative error better than 15 % and RSD less than 15 % for most determined trace elemems. LOD ranges from 0.021 × 10-6 to 0. 23 × 10-6 and less than 0.10 × 10-6 for majority trace elements determined. In addition, home-made macro functions including filter and calculator compiled by VBA language under Excel software greatly enhanced off-line data reduction efficiency.``

  17. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    Science.gov (United States)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  18. Alumina-carbon nanofibers nanocomposites obtained by spark plasma sintering for proton exchange membrane fuel cell bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, A.; Torrecillas, R. [Centro de Investigacion en Nanomateriales y Nanotecnologia (CINN) Consejo Superior de Investigaciones Cientificas, Universidad de Oviedo, Principado de Asturias, Parque Tecnologico de Asturias, Llanera Asturias (Spain); Rocha, V.G.; Fernandez, A. [ITMA Materials Technology, Parque Tecnologico de Asturias, Llanera Asturias (Spain)

    2012-08-15

    There is an increasing demand of multifunctional materials for a wide variety of technological developments. Bipolar plates for proton exchange membrane fuel cells are an example of complex functionality components that must show among other properties high mechanical strength, electrical, and thermal conductivity. The present research explored the possibility of using alumina-carbon nanofibers (CNFs) nanocomposites for this purpose. In this study, it was studied for the first time the whole range of powder compositions in this system. Homogeneous powders mixtures were prepared and subsequently sintered by spark plasma sintering. The materials obtained were thoroughly characterized and compared in terms of properties required to be used as bipolar plates. The control on material microstructure and composition allows designing materials where mechanical or electrical performances are enhanced. A 50/50 vol.% alumina-CNFs composite appears to be a very promising material for this kind of application. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Magnetic properties of single crystalline expanded austenite obtained by plasma nitriding of austenitic stainless steel single crystals.

    Science.gov (United States)

    Menéndez, Enric; Templier, Claude; Garcia-Ramirez, Pablo; Santiso, José; Vantomme, André; Temst, Kristiaan; Nogués, Josep

    2013-10-23

    Ferromagnetic single crystalline [100], [110], and [111]-oriented expanded austenite is obtained by plasma nitriding of paramagnetic 316L austenitic stainless steel single crystals at either 300 or 400 °C. After nitriding at 400 °C, the [100] direction appears to constitute the magnetic easy axis due to the interplay between a large lattice expansion and the expected decomposition of the expanded austenite, which results in Fe- and Ni-enriched areas. However, a complex combination of uniaxial (i.e., twofold) and biaxial (i.e., fourfold) in-plane magnetic anisotropies is encountered. It is suggested that the former is related to residual stress-induced effects while the latter is associated to the in-plane projections of the cubic lattice symmetry. Increasing the processing temperature strengthens the biaxial in-plane anisotropy in detriment of the uniaxial contribution, in agreement with a more homogeneous structure of expanded austenite with lower residual stresses. In contrast to polycrystalline expanded austenite, single crystalline expanded austenite exhibits its magnetic easy axes along basic directions.

  20. Determination of uranium from nuclear fuel in environmental samples using inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, S.F. [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen]|[Radiation Physics and Chemistry Problems Inst., Minsk (Belarus); Becker, J.S. [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen

    2000-11-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The {sup 236}U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on inductively coupled plasma quadrupole mass spectrometry with a hexapole collision cell (HEX-ICP-QMS). The figures of merit of the HEX-ICP-QMS were studied with a plasma-shielded torch using different nebulizers (such as an ultrasonic nebulizer (USN) and Meinhard nebulizer) for solution introduction. A {sup 238}U{sup +} ion intensity of up to 27000 MHz/ppm in HEX-ICP-QMS with USN was observed by introducing helium into the hexapole collision cell as the collision gas at a flow rate of 10 ml min{sup -1}. The formation rate of uranium hydride ions UH{sup +}/U{sup +} of 2 x 10{sup -6} was obtained by using USN with a membrane desolvator. The limit of {sup 236}U/{sup 238}U ratio determination in 10 {mu}g 1{sup -1} uranium solution was 3 x 10{sup -7} corresponding to the detection limit for {sup 236}U of 3 pg 1{sup -1}. The precision of uranium isotopic ratio measurements in 10 {mu}g 1{sup -1} laboratory uranium isotopic standard solution was 0.13% ({sup 235}U/{sup 238}U) and 0.33% ({sup 236}U/{sup 238}U) using a Meinhard nebulizer and 0.45% ({sup 235}U/{sup 238}U) and 0.88% ({sup 236}U/{sup 238}U) using a USN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the {sup 236}U/{sup 238}U ratio ranged from 10{sup -5} to 10{sup -3}. (orig.)

  1. Comparing capillary electrophoresis-mass spectrometry fingerprints of urine samples obtained after intake of coffee, tea, or water.

    Science.gov (United States)

    Allard, Erik; Bäckström, Daniel; Danielsson, Rolf; Sjöberg, Per J R; Bergquist, Jonas

    2008-12-01

    Metabolomic fingerprinting is a growing strategy for characterizing complex biological samples without detailed prior knowledge about the metabolic system. A two-way analysis system with liquid separation and mass spectrometric detection provides detail-rich data suitable for such fingerprints. As a model study, human urine samples, obtained after intake of coffee, tea, or water, were analyzed with capillary electrophoresis electrospray ionization time-of-flight mass spectrometry (CE-ESI-TOF-MS). In-house-developed software (in Matlab) was utilized to manage and explore the large amount of data acquired (230 CE-MS runs, each with 50-100 million nonzero data points). After baseline and noise reduction, followed by suitable binning in time and m/z, the data sets comprised 9 and 14 million data points in negative and positive ESI mode, respectively. Finally, a signal threshold was applied, further reducing the number to about 100 000 data points per data set. A set of interactive exploratory tools, utilizing principal component analysis (PCA) and analysis of variance (ANOVA) results based on a general linear model, facilitated visual interpretation with score plots (for group assessment) and differential fingerprints (for "hot spot" detection). In the model study highly significant differences due to beverage intake were obtained among the 10 first principal components (p coffee" and "tea or water" indicated several "hot spots" with highly elevated intensities (e.g., for uncharged masses 93, 94, 109, 119, 123, 132, 148, 169, 178, 187, 190, and 193) suitable for further analysis, for example, with tandem MS.

  2. Measurement and Comparison of Organic Compound Concentrations in Plasma, Whole Blood, and Dried Blood Spot Samples.

    Science.gov (United States)

    Batterman, Stuart A; Chernyak, Sergey; Su, Feng-Chiao

    2016-01-01

    The preferred sampling medium for measuring human exposures of persistent organic compounds (POPs) is blood, and relevant sample types include whole blood, plasma, and dried blood spots (DBS). Because information regarding the performance and comparability of measurements across these sample types is limited, it is difficult to compare across studies. This study evaluates the performance of POP measurements in plasma, whole blood and DBS, and presents the distribution coefficients needed to convert concentrations among the three sample types. Blood samples were collected from adult volunteers, along with demographic and smoking information, and analyzed by GC/MS for organochlorine pesticides (OCPs), chlorinated hydrocarbons (CHCs), polychlorinated biphenyls (PCBs), and brominated diphenyl ethers (PBDEs). Regression models were used to evaluate the relationships between the sample types and possible effects of personal covariates. Distribution coefficients also were calculated using physically-based models. Across all compounds, concentrations in plasma were consistently the highest; concentrations in whole blood and DBS samples were comparable. Distribution coefficients for plasma to whole blood concentrations ranged from 1.74 to 2.26 for pesticides/CHCs, averaged 1.69 ± 0.06 for the PCBs, and averaged 1.65 ± 0.03 for the PBDEs. Regression models closely fit most chemicals (R (2) > 0.80), and whole blood and DBS samples generally showed very good agreement. Distribution coefficients estimated using biologically-based models were near one and did not explain the observed distribution. Among the study population, median concentrations of several pesticides/CHCs and PBDEs exceeded levels reported in the 2007-2008 National Health and Nutrition Examination Survey, while levels of other OCPs and PBDEs were comparable or lower. Race and smoking status appeared to slightly affect plasma/blood concentration ratios for several POPs. The experimentally

  3. Measurement and Comparison of Organic Compound Concentrations in Plasma, Whole Blood and Dried Blood Spot Samples

    Directory of Open Access Journals (Sweden)

    Stuart A Batterman

    2016-04-01

    Full Text Available The preferred sampling medium for measuring human exposures of persistent organic compounds (POPs is blood, and relevant sample types include whole blood, plasma, and dried blood spots (DBS. Because information regarding the performance and comparability of measurements across these sample types is limited, it is difficult to compare across studies. This study evaluates the performance of POP measurements in plasma, whole blood and DBS, and presents the distribution coefficients needed to convert concentrations among the three sample types. Blood samples were collected from adult volunteers, along with demographic and smoking information, and analyzed by GC/MS for organochlorine pesticides (OCPs, chlorinated hydrocarbons (CHCs, polychlorinated biphenyls (PCBs, and brominated diphenyl ethers (PBDEs. Regression models were used to evaluate the relationships between the sample types and possible effects of personal covariates. Distribution coefficients also were calculated using physically-based models.Across all compounds, concentrations in plasma were consistently the highest; concentrations in whole blood and DBS samples were comparable. Distribution coefficients for plasma to whole blood concentrations ranged from 1.74 to 2.26 for pesticides/CHCs, averaged 1.69 ± 0.06 for the PCBs, and averaged 1.65 ± 0.03 for the PBDEs. Regression models closely fit most chemicals (R2 > 0.80, and whole blood and DBS samples generally showed very good agreement. Distribution coefficients estimated using biologically-based models were near one and did not explain the observed distribution. Among the study population, median concentrations of several pesticides/CHCs and PBDEs exceeded levels reported in the 2007-2008 National Health and Nutrition Examination Survey, while levels of other OCPs and PBDEs were comparable or lower. Race and smoking status appeared to slightly affect plasma/blood concentration ratios for several POPs. The experimentally

  4. A needle extraction utilizing a molecularly imprinted-sol-gel xerogel for on-line microextraction of the lung cancer biomarker bilirubin from plasma and urine samples.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Jabbar, Dunia; Colmsjö, Anders; Abdel-Rehim, Mohamed

    2014-10-31

    In the present work, a needle trap utilizing a molecularly imprinted sol-gel xerogel was prepared for the on-line microextraction of bilirubin from plasma and urine samples. Each prepared needle could be used for approximately one hundred extractions before it was discarded. Imprinted and non-imprinted sol-gel xerogel were applied for the extraction of bilirubin from plasma and urine samples. The produced molecularly imprinted sol-gel xerogel polymer showed high binding capacity and fast adsorption/desorption kinetics for bilirubin in plasma and urine samples. The adsorption capacity of molecularly imprinted sol-gel xerogel polymer was approximately 60% higher than that of non-imprinted polymer. The effect of the conditioning, washing and elution solvents, pH, extraction time, adsorption capacity and imprinting factor were investigated. The limit of detection and the lower limit of quantification were set to 1.6 and 5nmolL(-1), respectively using plasma or urine samples. The standard calibration curves were obtained within the concentration range of 5-1000nmolL(-1) in both plasma and urine samples. The coefficients of determination values (R(2)) were ≥0.998 for all runs. The extraction recovery was approximately 80% for BR in the human plasma and urine samples.

  5. Thermal barrier ZrO2 - Y2O3 obtained by plasma spraying method and laser melting

    OpenAIRE

    2006-01-01

    Purpose: The aim of the paper is to determine the influence of laser melting upon the selected physical properties of ZrO2 - Y2O3 ceramic coatings deposited by APS (Air Plasma Spraying) method on super-alloys which function as TBC (Thermal Barriers Coatings).Design/methodology/approach: Laser melting which helps eliminate pores and other structural defects of coatings deposited by plasma spraying method should contribute to the improvement of their density and durability as thermal barriers. ...

  6. Effects of storage time on total protein and globulin concentrations in bovine fresh frozen plasma obtained for transfusion.

    Science.gov (United States)

    Proverbio, D; Spada, E; Baggiani, L; Bagnagatti De Giorgi, G; Roggero, N; Belloli, A; Pravettoni, D; Perego, R

    2015-01-01

    To evaluate the effects of storage conditions on total protein (TP) and globulin fractions in fresh frozen bovine plasma units prepared and stored for transfusion, TP and globulin fractions were evaluated in fresh plasma and at 1 month and 6 and 12 months after blood collection in plasma stored at -20°C. Significant differences in concentrations were found in the median concentration of total protein (P=0.0336), between 0 months and 1 month (P=0.0108), 0 and 6 months (P=0.0023), and 0 and 12 months (P=0.0027), in mean concentration (g/dL) of albumin (P=0.0394), between 0 months and 1 month (P=0.0131), 0 and 6 months (P=0.0035), and 0 and 12 months (P=0.0038), and beta-2 fraction (P=0.0401), between 0 and 6 months (P=0.0401) and 0 and 12 months (P=0.0230). This study suggests that total gamma globulin concentration in bovine frozen plasma is stable for 12 months at -20°C. Total protein, ALB, and beta-2 fraction have significantly different concentrations (g/dL) when compared to prestorage. This study has shown IgG protein fraction stability in bovine fresh frozen plasma collected for transfusion; therefore, bovine fresh frozen plasma seems to be suitable for the treatment of hypogammaglobulinemia (failure of passive transfer) in calves when stored for 12 months at -20°C.

  7. Liquid chromatography-mass spectrometric determination of rufinamide in low volume plasma samples.

    Science.gov (United States)

    Gáll, Zsolt; Vancea, Szende; Dogaru, Maria T; Szilágyi, Tibor

    2013-12-01

    Quantification of rufinamide in plasma was achieved using a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method. The chromatographic separation was achieved on a reversed phase column (Zorbax SB-C18 100mm×3mm, 3.5μm) under isocratic conditions. The mobile phase consisted of a mixture of water containing 0.1% formic acid and methanol (50:50, v/v). The mass spectrometric detection of the analyte was in multiple reaction monitoring mode (MRM) using an electrospray positive ionization (ESI positive). The monitored ions were 127m/z derived from 239m/z rufinamide and 108m/z derived from 251m/z the internal standard (lacosamide). Protein precipitation with methanol was applied for sample preparation using only 50μl aliquots. The concentration range was 40-2000ng/ml for rufinamide in plasma. The limit of detection was 1.25ng/ml and the lower limit of quantification was established at 5ng/ml rufinamide concentration. Selectivity and matrix effect was verified using individual human, rat and rabbit plasma samples. Short-term, post-preparative and freeze-thaw stability was also investigated. The proposed method provides accuracy, precision and high-throughput (short runtime 4.5min) for quantitative determination of rufinamide in plasma. This is the first reported liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for analysis of rufinamide from low volume plasma samples. The LC-MS/MS method was validated according to the current official guidelines and can be applied to accurately measure rufinamide level of large number of plasma samples from clinical studies or therapeutic drug monitoring.

  8. Measurement of glomerular filtration rate in adults: accuracy of five single-sample plasma clearance methods

    DEFF Research Database (Denmark)

    Rehling, M; Rabøl, A

    1989-01-01

    After an intravenous injection of a tracer that is removed from the body solely by filtration in the kidneys, the glomerular filtration rate (GFR) can be determined from its plasma clearance. The method requires a great number of blood samples but collection of urine is not needed. In the present...

  9. Roseomonas tokyonensis sp. nov. isolated from a biofilm sample obtained from a cooling tower in Tokyo, Japan.

    Science.gov (United States)

    Furuhata, Katsunori; Ishizaki, Naoto; Edagawa, Akiko; Fukuyama, Masafumi

    2013-01-01

    Strain K-20(T), a Gram-negative, nonmotile, nonspore-forming and strictly aerobic coccobacillus, which produces a pale pink pigment (R2A agar medium, 30℃, seven days) was isolated from a sample of biofilm obtained from a cooling tower in Tokyo, Japan. A phylogenetic analysis of the 16S rRNA partial gene sequences (1,439 bp) showed that the strain (accession number: AB297501) was related to Roseomonas frigidaquae CW67(T) and Roseomonas stagni HS-69(T) with 97.4% and 96.9% sequence similarity, respectively. Strain K-20(T) formed a distinct cluster with Roseomonas frigidaquae CW67(T) in the phylogenetic tree at a high bootstrap value (93%); however, distance was recognized between the strains. In addition, the DNA-DNA hybridization level between strain K-20(T) and Roseomonas frigidaquae JCM 15073(T) was 33%. The taxonomic data indicate that K-20(T) (=JCM 14634(T) =KCTC 32152(T)) should be classified in the genus Roseomonas as the type strain of a novel species, Roseomonas tokyonensis sp. nov.

  10. Real-Time PCR in faecal samples of Triatoma infestans obtained by xenodiagnosis: proposal for an exogenous internal control.

    Science.gov (United States)

    Bravo, Nicolás; Muñoz, Catalina; Nazal, Nicolás; Saavedra, Miguel; Martínez, Gabriela; Araya, Eduardo; Apt, Werner; Zulantay, Inés

    2012-03-26

    The polymerase chain reaction (PCR) has proved to be a sensitive technique to detect Trypanosoma cruzi in the chronic phase of Chagas disease, which is characterized by low and fluctuating parasitemia. Another technique proposed for parasitological diagnosis in this phase of infection combines a microscopic search for motile trypomastigote forms in faecal samples (FS) obtained by xenodiagnosis (XD) with conventional PCR (XD-PCR). In this study we evaluate the use of human blood DNA as an exogenous internal control (EIC) for real time PCR (qPCR) combined with XD (XD-qPCR) using chromosome 12 (X12) detection. None of the FS-XD evaluated by qPCR amplified for X12. Nevertheless, all the EIC-FS-XD mixtures amplified for X12. We determined that X12 is useful as an EIC for XD-qPCR because we showed that the FS-XD does not contain human DNA after 30 or more days of XD incubation. This information is relevant for research on T. cruzi by XD-qPCR since it allows ruling out inhibition and false negative results due to DNA loss during the process of extraction and purification.

  11. Direct determination of sulfur species in coals from the Argonne premium sample program by solid sampling electrothermal vaporization inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Bauer, Daniela; Vogt, Thomas; Klinger, Mathias; Masset, Patrick Joseph; Otto, Matthias

    2014-10-21

    A new direct solid sampling method for speciation of sulfur in coals by electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP OES) is presented. On the basis of the controlled thermal decomposition of coal in an argon atmosphere, it is possible to determine the different sulfur species in addition to elemental sulfur in coals. For the assignment of the obtained peaks from the sulfur transient emission signal, several analytical techniques (reflected light microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction) were used. The developed direct solid sampling method enables a good accuracy (relative standard deviation ≤ 6%), precision and was applied to determine the sulfur forms in the Argonne premium coals, varying in rank. The generated method is time- and cost-effective and well suited for the fast characterization of sulfur species in coal. It can be automated to a large extent and is applicable for process-accompanying analyses.

  12. Radionuclide Determination In Surface Water Samples By Inductively Coupled Plasma With Sector Field Mass Spectrometry (ICP-SFMS

    Directory of Open Access Journals (Sweden)

    E. T. Romero-Guzmán

    2016-08-01

    Full Text Available The determination of naturally occurring radionuclides in the environment by inductively coupled plasma mass spectrometry of high resolution (ICP-SFMS has gained recognition over the last fifteen years, relative to the radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels of many radioisotopes. The aim of this work was to determined the natural radionuclides (232Th, 234U, 235U and 238U in surface water using Inductively Coupled PlasmaSector Field Mass Spectrometry (ICP-SFMS. The samples were sampling from Lerma river, State of Mexico at february to april 2015. The process of treatment of sample consisted in perform an acid digestion according to the 3015A USEPA method followed of the direct measurement in ICP-SFMS. Results obtained were: a identify the presence of 232Th, 234U, 235U and 238U isotopes in water, b isotopic ratios were for 234U/238U=1.133 ± 0.016. ICPSFMS has gained popularity in the field of radiochemistry, particularly as a method of detection for long lived-actinides.

  13. Demonstration of a frozen sample aliquotter to prepare plasma and serum aliquots without thawing frozen parent samples.

    Science.gov (United States)

    Ellis, Helena Judge; Venturini, Deborah S

    2013-06-01

    Human biospecimens represent invaluable resources to advance molecular medicine, epidemiology, and biomarker discovery/validation, among other biomedical research. Biobanks typically cryopreserve biospecimens to safeguard their biochemical composition. However, exposing specimens repeatedly to freeze/thaw cycles can degrade their integrity in unforeseen ways. Those biobanks storing liquid samples, thus, regularly make a fundamental compromise at collection time between freezing samples in many small volumes (e.g., 0.5 mL or smaller) or in fewer, larger volumes (e.g., 1.8 mL). The former eliminates the need to expose samples to repeated freeze/thaw cycling, although increasing up-front labor costs, consumables used, and cold storage space requirements. The latter decreases up-front labor costs, consumables, and cold storage requirements, yet exposes samples repeatedly to damaging freeze/thaw cycles when smaller aliquots are needed for analysis. The Rhode Island BioBank at Brown University (RIBB) thoroughly evaluated the performance of an original technology that minimizes a sample's exposure to freeze/thaw cycling by enabling the automated extraction of frozen aliquots from one single frozen parent sample without thawing it. A technology that eliminates unnecessary sample exposures to freeze/thaw cycles could help protect sample integrity, extend its useful life, and effectively rectify and eliminate the aforementioned need to compromise. This report presents the results of the evaluation, and conclusively demonstrates the technology's ability to extract multiple uniform frozen aliquots from a single cryotube of never-thawed frozen human plasma, which faithfully represent the parent sample when analyzed for typical biochemical analytes, showing a coefficient of variability lower than 5.5%.

  14. New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry

    Science.gov (United States)

    Montaser, A.

    This research follows a multifaceted approach, from theory to practice, to the investigation and development of novel helium plasmas, sample introduction systems, and diagnostic techniques for atomic and mass spectrometries. During the period January 1994 - December 1994, four major sets of challenging research programs were addressed that each included a number of discrete but complementary projects: (1) The first program is concerned with fundamental and analytical investigations of novel atmospheric-pressure helium inductively coupled plasmas (He ICPS) that are suitable for the atomization-excitation-ionization of elements, especially those possessing high excitation and ionization energies, for the purpose of enhancing sensitivity and selectivity of analytical measurements. (2) The second program includes simulation and computer modeling of He ICPS. The aim is to ease the hunt for new helium plasmas by predicting their structure and fundamental and analytical properties, without incurring the enormous cost for extensive experimental studies. (3) The third program involves spectroscopic imaging and diagnostic studies of plasma discharges to instantly visualize their prevailing structures, to quantify key fundamental properties, and to verify predictions by mathematical models. (4) The fourth program entails investigation of new, low-cost sample introduction systems that consume micro- to nanoliter quantity of sample solution in plasma spectrometries. A portion of this research involves development and applications of novel diagnostic techniques suitable for probing key fundamental properties of aerosol prior to and after injection into high-temperature plasmas. These efforts, still in progress, collectively offer promise of solving singularly difficult analytical problems that either exist now or are likely to arise in the future in the various fields of energy generation, environmental pollution, material science, biomedicine and nutrition.

  15. Online Determination of Sm, Eu and Yb in Environmental Samples by Inductively Coupled Plasma – Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dilip Kumar

    2007-01-01

    Full Text Available A procedure was developed for the determination of Sm, Eu and Yb in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES after preconcentration on synthesized 5-(4-pyridyl azo-8-quinolinol supported by Borassus flabellifer inflorescence (BFI. The sorbed element was subsequently eluted with 0.4 M HNO3 and the acid eluates were analyzed by ICP-OES. Under the optimal conditions, Sm, Eu and Yb in aqueous samples were concentrated 100-fold. Recoveries were obtained by the proposed method in the range of 98.6 -99.8%. This method was also applied for the analysis of spiked and natural water samples. The results provide strong evidence to support the hypothesis of an adsorption mechanism.

  16. Study of electrochemical properties of thin film materials obtained using plasma technologies for production of electrodes for pacemakers

    Science.gov (United States)

    Obrezkov, O. I.; Vinogradov, V. P.; Krauz, V. I.; Mozgrin, D. V.; Guseva, I. A.; Andreev, E. S.; Zverev, A. A.; Starostin, A. L.

    2016-09-01

    Studies of thin film materials (TFM) as coatings of tips of pacemaker electrodes implanted into the human heart have been performed. TFM coatings were deposited in vacuum by arc magnetron discharge plasma, by pulsed discharge of “Plasma Focus”, and by electron beam evaporation. Simulation of electric charge transfer to the heart in physiological blood- imitator solution and determination of electrochemical properties of the coatings were carried out. TFM of highly developed surface of contact with tissue was produced by argon plasma spraying of titanium powder with subsequent coating by titanium nitride in vacuum arc assisted by Ti ion implantation. The TFM coatings of pacemaker electrode have passed necessary clinical tests and were used in medical practice. They provide low voltage myocardium stimulation thresholds within the required operating time.

  17. [Quantitative and qualitative bacteriological studies on urine specimens obtained by suprapubic needle aspiration and on midstream-voided samples].

    Science.gov (United States)

    Augustin, R; Seybold, G; Witzenhausen, R; Hessler, M; Niemeyer, G

    1978-06-24

    In 398 patients with suspected urinary tract infection, quantitative and qualitative bacteriological studies were conducted in urine samples obtained by suprapubic needle aspiration of the bladder (BPU) and in midstream-voided specimens (MSU) collected immediately following the aspirations. In MSU, bacteria were found in 96.5% of all cases and in BPU in only 38.2%. Of the infected MSU, 63.3% showed mixed infections, while mixed cultures were found in only 11.2% of infected BPU. In 80% of the investigated patients, the MSU contained at least one more type of bacteria than the BPU, thus indicating urethral contamination. Of the patients with bladder bacteriuria, only 74% had bacterial counts of 10(5)/ml or more in the midstream-voided urine. Accordingly, 26% of the urinary tract infections diagnosed by bladder aspiration would not have been recognized on the basis of a single bacterial count in the midstream-voided urine. On the other hand, about 4% of patients with bacterial counts of 10(5)/ml or more in the MSU had a sterile bladder aspirate. In 72.4% of the infected BPU, E. coli was found, followed in frequency by Enterococcus (14.5%). In the infected MSU, however, Enterococcus was more frequent than C. coli (65.6% and 61.7% respectively). Thus, E. coli appears to be the most important etiological species in infections of the bladder and the kidneys, while Enterococcus seems to be the most frequent contaminant during urethral passage. The most frequent bacterial combination in mixed cultures in both BPU and MSU was that of E. coli and Enterococcus.

  18. Effects of fruit and vegetable consumption on total antioxidant capacity of fasting and postprandial plasma samples

    DEFF Research Database (Denmark)

    Ravn-Haren, Gitte; Dragsted, L. O.; Pedersen, A.

    2001-01-01

    Fruits and vegetables are known to protect against cancer and heart disease. This is often ascribed to their high content of antioxidants. We have therefore tested whether a daily intake of fruits and vegetables corresponding to the recommended 600 g had any effect on the antioxidant activity of ...... of fasting and postprandial plasma samples. Antioxidant activity was determined by the Trolox Equivalent Antioxidant Capacity (TEAC) assay and the Ferric Reducing Ability of Plasma (FRAP) assay, which have been reported to be affected by the presence of dietary antioxidants....

  19. Analysis of inflammatory response in human plasma samples by an automated multicapillary electrophoresis system.

    Science.gov (United States)

    Larsson, Anders; Hansson, Lars-Olof

    2004-01-01

    A new automated multicapillary zone electrophoresis instrument with a new high-resolution (HR) buffer (Capillarys with HR buffer) for analysis of human plasma proteins was evaluated. Albumin, alpha(1)-antitrypsin, alpha(1)-acid glycoprotein, haptoglobin, fibrinogen, immunoglobulin (Ig)A, IgG and IgM were determined nephelometrically in 200 patient plasma samples. The same samples were then analyzed on the Capillarys system (Sebia, Paris, France). The albumin concentration from the nephelometric determination was used for quantification of the individual peaks in the capillary electrophoresis (CE) electropherogram. There was strong linear correlation between the nephelometric and electrophoretic determination of alpha(1)-antitrypsin (R(2) = 0.906), alpha(1)-acid glycoprotein (R(2) =0.894) and haptoglobin (R(2) = 0.913). There was also good correlation between the two determinations of gamma-globulins (R(2) = 0.883), while the correlation was weaker for fibrinogen (R(2) = 0.377). The Capillarys instrument is a reliable system for plasma protein analysis, combining the advantages of full automation, good analytical performance and high throughput. The HR buffer in combination with albumin quantification allows the simultaneous quantification of inflammatory markers in plasma samples without the need for nephelometric determination of these proteins.

  20. The evaluation of dioxin and dioxin-like contaminants in selected food samples obtained from the Belgian market: comparison of TEQ measurements obtained through the CALUX bioassay with congener specific chemical analyses.

    Science.gov (United States)

    Schoeters, Greet; Goyvaerts, Marie Pierre; Ooms, Daniëlla; Van Cleuvenbergen, Rudy

    2004-03-01

    A limited number of different foods were analysed for dioxin-like compounds by the CALUX bioassay which is an in vitro luciferase reporter gene assay measuring chemical activation of the aryl hydrocarbon receptor. Sixty-two milk samples were obtained from a surveillance campaign, 34 meat samples and 34 fishery products were purchased from the Belgian market. Bio-analytical and chemo-analytical dioxin toxicity equivalents (TEQ) values of the same milk samples were compared. Spearman's Rank correlation coefficients of 0.72, 0.67, 0.73 were obtained respectively between CALUX-TEQ and PCDD/F-TEQ, DL-PCB-TEQ and PCDD/F+DL-PCB-TEQ. The bioassay limit of detection was 0.1 pg TEQ from 1 g animal lipid, the limit of quantification was 0.4 pg TEQ. The repeatability of the CALUX bioassay (variability of butter fat samples analysed in the same run) showed a coefficient of variation (CV) of 10%, intra laboratory reproducibility based on independent runs of the same butter fat samples showed more variation (CV of 26% for samples above 2 pg TEQ/g lipid). All milk samples with a chemical TEQ value above the current limit value in Belgium showed an elevated CALUX-TEQ concentration, above 6 pg TEQ/g lipid. No false negative results were obtained. Based on the good correlation between CALUX-TEQ and chemically measured TEQ levels, the CALUX bioassay can be recommended as a screening tool for routine measurement of potentially toxic PHAHs in milk samples. Chemical analyses could then largely be restricted to positive samples, in order to identify the nature and to quantify the concentration of the chemicals that give the positive signal. Meat samples showed lower CALUX-TEQ values per gram lipid compared to fish samples. The fish samples showed a wider range of CALUX-TEQ values than the meat samples.

  1. Solid-Sampling Electrothermal Vaporization Inductively Coupled Plasma Optical Emission Spectrometry for Direct Determination of Total Oxygen in Coal.

    Science.gov (United States)

    Vogt, Thomas; Bauer, Daniela; Nennstiel, David; Otto, Matthias

    2015-10-20

    A new analytical method for direct determination of total oxygen contents in eight coal samples of the Argonne Premium Coal (APC) series and in the NIST SRM 1632d is presented. The development of a suitable calibration procedure, optimization of measurement conditions, and the application of a tailored data processing for handling of plasma effects and high blanks enable the quantification of oxygen simultaneously with other trace, minor, or major elements in whole coal samples by means of electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP OES). For comparison, the oxygen contents were determined by a direct oxygen analyzer. The obtained oxygen values of the APC and the reference material NIST SRM 1632d were compared to data in the literature. The precision of the ETV-ICP OES was within ±3.5%, and the recovery better than 92%. With this good accuracy, the developed direct solid sampling method ETV-ICP OES is well suited for the fast determination of oxygen in coals, varying in rank from lignite to semianthracite, in a content range of about 100 ppm up to 27% using 1.5 mg sample weight. This direct analysis method represents an accurate, advantageous alternative to currently used methods for estimation of total oxygen contents in coals.

  2. Development of x-ray and ion diagnostics of plasma obtained with a 10-TW femtosecond laser

    Science.gov (United States)

    Ryć, L.; Dobrzański, L.; Dubecky, F.; Jabłoński, S.; Parys, P.; Słysz, W.; Rosiński, M.

    2016-07-01

    Several x-ray and ion semiconductor detectors have been developed for the diagnostics of femtosecond laser plasma generated by a 10-TW laser which was recently commissioned for operation at the Institute of Plasma Physics and Laser Microfusion, Warsaw. A range of detectors has been employed including a CdTe detector for hard x-rays and four detectors for proton detection. These four are SiC and GaN employing a sandwich structure, an interdigitated M-S-M InP detector and finally a silicon photo-diode equipped with an aluminium filter (to shield against scattered light). The detectors presented are innovative as they are not commonly used for the diagnostic of laser plasma. The details of the internal structures of the detectors are presented. The immunity of the detectors to the noise coming from the laser system and the femtosecond plasma is discussed. Lastly, the possibility for further modifications and improvements are considered and discussed.

  3. Overestimation of canine albumin concentration with the bromcresol green method in heparinized plasma samples.

    Science.gov (United States)

    Stokol, Tracy; Tarrant, Jacqueline M.; Scarlett, Janet M.

    2001-01-01

    Albumin concentrations are routinely measured in dogs with bromcresol green (BCG)-binding assays on automated chemistry analyzers. Several variables affect this assay, including the length of reaction time, sample type, and lack of specificity of BCG for albumin. We observed that albumin concentrations measured with BCG appeared higher in heparinized plasma samples in sick dogs. The objective of this study was to determine the effect of anticoagulant and assay procedure on BCG albumin concentrations in clinically ill dogs. We hypothesized that albumin concentrations would be overestimated in heparinized plasma compared with serum because of the combination of heparin and fibrinogen. Furthermore, we hypothesized that the overestimation would be influenced by assay parameters. Blood was collected from 32 clinically ill dogs into tubes containing heparin, citrate, or no anticoagulant. Citrate was chosen to assess the effect of fibrinogen in the absence of heparin. Albumin concentration was measured in all 3 sample types from each dog using 2 different BCG procedures on an automated chemistry analyzer. The BCG procedures (standard and modified) differed in the wavelengths used for absorbance readings (standard, 600/700; modified, 570/505) and the time point at which absorbance was measured (standard, 100 seconds; modified, 40 seconds). In addition, the modified method incorporated a sample blank. Globulin fractions, fibrinogen concentration, and indices of lipemia, hemolysis, and icterus were evaluated for their contribution to the overestimation of albumin concentration in heparinized plasma compared with serum samples. Albumin concentrations were significantly higher (P plasma (mean +/- SE, 3.8 +/- 0.1 g/dL) than in serum (3.6 +/- 0.2 g/dL) or citrated plasma (3.2 +/- 0.1 g/dL). Overestimation was evident only with the standard BCG procedure. Multiple linear regression analysis indicated that fibrinogen was largely responsible for the higher

  4. Development of a simple device for processing whole-blood samples into measured aliquots of plasma.

    Science.gov (United States)

    Burtis, C A; Johnson, W F; Walker, W A

    1986-09-01

    A capillary processor and aliquoter has been designed and fabricated that is capable of accepting aliquots of whole blood and automatically processing them into discrete aliquots of plasma. The device consists of two disks, each of which contains 16 individual capillaries and a processing rotor. One disk accepts larger capillaries that hold approximately 100 microL of whole blood each. The second disk accepts 2.54-cm-long precision capillaries of various internal diameters, which provide exact sample volumes from 1 to 10 microL. The processing rotor contains 16 individual compartments and chambers to accept both disks. Applying centrifugal force transfers the aliquots of whole blood into their respective compartments, where they are separated into cellular and plasma fractions. As the rotor speed is slowly decreased, an aliquot of plasma is withdrawn by capillary action into each measuring capillary. The disk containing the 16 measured aliquots of plasma is then removed and placed into a modified rotor for conventional centrifugal analysis. This device can entrain and deliver microliter volumes of liquids with precision and accuracy (1-2%) near that of mechanical pipettes. Assays of the separated plasma aliquots also have acceptable precision (e.g., CVs approximately 3% for measurements of serum enzymes).

  5. Assessing representativeness of sampling methods for reaching men who have sex with men: a direct comparison of results obtained from convenience and probability samples.

    Science.gov (United States)

    Schwarcz, Sandra; Spindler, Hilary; Scheer, Susan; Valleroy, Linda; Lansky, Amy

    2007-07-01

    Convenience samples are used to determine HIV-related behaviors among men who have sex with men (MSM) without measuring the extent to which the results are representative of the broader MSM population. We compared results from a cross-sectional survey of MSM recruited from gay bars between June and October 2001 to a random digit dial telephone survey conducted between June 2002 and January 2003. The men in the probability sample were older, better educated, and had higher incomes than men in the convenience sample, the convenience sample enrolled more employed men and men of color. Substance use around the time of sex was higher in the convenience sample but other sexual behaviors were similar. HIV testing was common among men in both samples. Periodic validation, through comparison of data collected by different sampling methods, may be useful when relying on survey data for program and policy development.

  6. Low gas flow inductively coupled plasma optical emission spectrometry for the analysis of food samples after microwave digestion.

    Science.gov (United States)

    Nowak, Sascha; Gesell, Monika; Holtkamp, Michael; Scheffer, Andy; Sperling, Michael; Karst, Uwe; Buscher, Wolfgang

    2014-11-01

    In this work, the recently introduced low flow inductively coupled plasma optical emission spectrometry (ICP-OES) with a total argon consumption below 0.7 L/min is applied for the first time to the field of food analysis. One goal is the investigation of the performance of this low flow plasma compared to a conventional ICP-OES system when non-aqueous samples with a certain matrix are introduced into the system. For this purpose, arsenic is determined in three different kinds of fish samples. In addition several nutrients (K, Na, Mg, Ca) and trace metals (Co, Cu, Mn, Cd, Pb, Zn, Fe, and Ni) are determined in honey samples (acacia) after microwave digestion. The precision of the measurements is characterized by relative standard deviations (RSD) and compared to the corresponding precision values achieved using the conventional Fassel-type torch of the ICP. To prove the accuracy of the low flow ICP-OES method, the obtained data from honey samples are validated by a conventional ICP-OES. For the measurements concerning arsenic in fish, the low flow ICP-OES values are validated by conventional Fassel-type ICP-OES. Furthermore, a certified reference material was investigated with the low gas flow setup. Limits of detection (LOD), according to the 3σ criterion, were determined to be in the low microgram per liter range for all analytes. Recovery rates in the range of 96-106% were observed for the determined trace metal elements. It was proven that the low gas flow ICP-OES leads to results that are comparable with those obtained with the Fassel-type torch for the analysis of food samples.

  7. Effect of storage conditions on prothrombin time, activated partial thromboplastin time and fibrinogen concentration on canine plasma samples

    Science.gov (United States)

    Casella, Stefania; Giannetto, Claudia; Giudice, Elisabetta

    2010-01-01

    The present study was to assess the effect of storage conditions on prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen concentration in blood samples of healthy dogs. Thirty-five dogs of various breeds were included in the study. Citrated blood samples were obtained and plasma was divided into four aliquots to assess selected clotting parameters by means of a coagulometer. The first aliquot was analysed within 1 h after collection, while the remaining 3 were stored at 8℃ for 4, 8 and 24 h, respectively. One-way repeated measures analysis of variance documented a significant decreasing effect on PT at 24 h compared to 8 h and on fibrinogen concentration after 8 and 24 h compared to sampling time and at 4 and 24 h compared to 8 h post sampling. In conclusion, the results of this study indicate that only fibrinogen appears prone to significant decrease. In fact, aPTT is not substantially affected by refrigeration for at least 24 h post sampling and PT showed a statistical difference that does not necessary indicate biological significance as the results obtained were within reference intervals for the dog. PMID:20458152

  8. Chimeric External Control to Quantify Cell Free DNA in Plasma Samples by Real Time PCR

    Science.gov (United States)

    Eini, Maryam; Behzad-Behbahani, Abbas; Takhshid, Mohammad Ali; Ramezani, Amin; Rafiei Dehbidi, Gholam Reza; Okhovat, Mohammad Ali; Farhadi, Ali; Alavi, Parniyan

    2016-01-01

    Background: DNA isolation procedure can significantly influence the quantification of DNA by real time PCR specially when cell free DNA (cfDNA) is the subject. To assess the extraction efficiency, linearity of the extraction yield, presence of co-purified inhibitors and to avoid problems with fragment size relevant to cfDNA, development of appropriate External DNA Control (EDC) is challenging. Using non-human chimeric nucleotide sequences, an EDC was developed for standardization of qPCR for monitoring stability of cfDNA concentration in blood samples over time. Methods: A0 DNA fragment of 167 bp chimeric sequence of parvovirus B19 and pBHA designated as EDC fragment was designed. To determine the impact of different factors during DNA extraction processing on quantification of cfDNA, blood samples were collected from normal subjects and divided into aliquots with and without specific treatment. In time intervals, the plasma samples were isolated. The amplicon of 167 bp EDC fragment in final concentration of 1.1 pg/500 μl was added to each plasma sample and total DNA was extracted by an in house method. Relative and absolute quantification real time PCR was performed to quantify both EDC fragment and cfDNA in extracted samples. Results: Comparison of real time PCR threshold cycle (Ct) for cfDNA fragment in tubes with and without specific treatment indicated a decrease in untreated tubes. In contrast, the threshold cycle was constant for EDC fragment in treated and untreated tubes, indicating the difference in Ct values of the cfDNA is because of specific treatments that were made on them. Conclusions: Spiking of DNA fragment size relevant to cfDNA into the plasma sample can be useful to minimize the bias due to sample preparation and extraction processing. Therefore, it is highly recommended that standard external DNA control be employed for the extraction and quantification of cfDNA for accurate data analysis. PMID:27141267

  9. Analysis of iodine in food samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Todorov, Todor I; Gray, Patrick J

    2016-01-01

    This work shows a method for the determination of iodine in a variety of food samples and reference materials using inductively coupled plasma-mass spectrometry (ICP-MS) following alkaline extraction. Optimisation of the addition of organic carbon showed that a minimum of 3% 2-propanol was necessary for a constant ratio of iodine to internal standard. The limit of quantification (LOQ), calculated as 30σ for the method, was 36 ng g(-1) in solid food samples. For method validation, seven standard reference materials (SRM) and 21 fortified food samples were used. The precision (%RSD) of the measurements was in the 2-7% range. Accuracies for the SRMs were 85-105%, while the fortified food samples showed 81-119% recoveries, including a number of samples fortified at 50% of the LOQ.

  10. Development of a highly specific enzyme immunoassay for oxytocin and its use in plasma samples.

    Science.gov (United States)

    Haraya, Shiomi; Karasawa, Koji; Sano, Yoshihiro; Ozawa, Kimiko; Kato, Nobumasa; Arakawa, Hidetoshi

    2017-01-01

    Background The peptide hormone oxytocin acts in the central nervous system and plays an important role in various complex social behaviours. We report the production of a high affinity and specificity antibody for oxytocin and its use in a highly sensitive enzyme immunoassay. Biotin that was chemically bound to oxytocin derivative containing zero to six lysines as bridge was the labelled antigen. Seven labelled antigens were used to develop a highly sensitive enzyme immunoassay. Methods Antioxytocin antiserum was obtained by immunization of oxytocin-bovine thyrogloblin conjugate to rabbit. Oxytocin sample was added to the second antibody-coated microtitre plate and allowed to react overnight at 4℃, then biotinylated oxytocin was added 1 h at 4℃, and horseradish peroxidase-labelled avidin was added and incubated for 1 h at room temperature. The plate was then washed. Horseradish peroxidase activity was measured by a colorimetric method using o-phenylenediamine (490 nm). Results The sensitivity of the enzyme immunoassay improved as the number of lysine residues increased; consequently, biotinylated oxytocin bridged with five lysines was used. A standard curve for oxytocin ranged from 1.0 to 1000 pg/assay. The detection limit of the assay was 2.36 pg, and the reproducibility was 3.6% as CV% ( n = 6). Cross-reactivity with vasopressin and vasotocin was less than 0.01%. Conclusion The sensitivity of the enzyme immunoassay could be improved by increasing the number of lysine residues on the biotin-labelled antigen. The proposed method is sensitive and more specific than conventional immunoassays for oxytocin and can be used to determine plasma oxytocin concentrations.

  11. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Juergen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aaron, A. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, Gary L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burgess, Thomas W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ellis, Ronald James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans, James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lessard, Timothy L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ohriner, Evan Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Perkins, Dale E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Varma, Venugopal Koikal [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-20

    -state heat fluxes of 5–20 MW/m2 and ion fluxes up to 1024 m-2s-1. Since PFCs will have to withstand neutron irradiation displacement damage up to 50 dpa, the target station design must accommodate radioactive specimens (materials to be irradiated in HFIR or at SNS) to enable investigations of the impact of neutron damage on materials. Therefore, the system will have to be able to install and extract irradiated specimens using equipment and methods to avoid sample modification, control contamination, and minimize worker dose. Included in the design considerations will be an assessment of all the steps between neutron irradiation and post-exposure materials examination/characterization, as well as an evaluation of the facility hazard categorization. In particular, the factors associated with the acquisition of radioactive specimens and their preparation, transportation, experimental configuration at the plasma-specimen interface, post-plasma-exposure sample handling, and specimen preparation will be evaluated. Neutronics calculations to determine the dose rates of the samples were carried out for a large number of potential plasma-facing materials.

  12. Development of a high throughput 96-well plate sample preparation method for the determination of trileptal (oxcarbazepine) and its metabolites in human plasma.

    Science.gov (United States)

    Souppart, C; Decherf, M; Humbert, H; Maurer, G

    2001-10-05

    A high throughput preparation method for the determination of trileptal (oxcarbazepine, OXC) and its mono (MHD) and dihydroxy (DHD) metabolites in human plasma, using 96-well plate technology, has been developed and validated according to international regulatory requirements. Preparation of plasma samples (50 microl) containing the compounds to be analysed involved solid-phase extraction (SPE) on Empore C18 96-well SPE plates. Eluates from the plate were injected onto a reversed-phase column (Hypersil C18,3 microm) with UV detection at 210 nm. Detector response was linear over the ranges 0.2-10, 0.1-200 and 0.1-20 micromol/l, for OXC, MHD and DHD, respectively, with relative standard deviations from 1 to 10% and mean accuracies within 4% of the nominal values (number of standard curves=3 in duplicate). The limits of quantitation were 0.2, 0.1 and 0.1 micromol/l, respectively. The overall mean accuracies ranged from 96 to 106% and precision was in the range 4 to 11%. Cross validation indicated no significant difference between plasma concentrations obtained using the 96-well method and the previous method using a traditional SPE method with a 50 mg C18 cartridge. About a threefold increase in sample throughput and a twofold decrease of plasma volume required for the assays, were the main advantages obtained from the previous method. The method was applied for the determination of 3000 plasma samples from clinical studies.

  13. A simple sample preparation method for measuring amoxicillin in human plasma by hollow fiber centrifugal ultrafiltration.

    Science.gov (United States)

    Dong, Wei-Chong; Hou, Zi-Li; Jiang, Xin-Hui; Jiang, Ye

    2013-02-01

    A simple sample preparation method has been developed for the determination of amoxicillin in human plasma by hollow fiber centrifugal ultrafiltration (HF-CF-UF). A 400-μL plasma sample was placed directly into the HF-CF-UF device, which consisited of a slim glass tube and a U-shaped hollow fiber. After centrifugation at 1.25 × 10(3) g for 10 min, the filtrate was withdrawn from the hollow fiber and 20 µL was directly injected into the high-performance liquid chromatography (HPLC) for analysis. The calibration curve was linear over the range of 0.1-20 µg/mL (r = 0.9996) and the limit of detection was as low as 0.025 µg/mL. The average recovery and absolute recovery were 99.9% and 84.5%, respectively. Both the intra-day and inter-day precisions (relative standard deviation) were less than 3.1% for three concentrations (0.25, 2.5 and 10 µg/mL). The sample preparation process was simplified. Only after a single centrifugal ultrafiltration can the filtrate be injected directly into HPLC. The present method is simple, sensitive and accurate. It could be effective for the analysis of biological samples with high protein contents, especially for the biopharmaceutical analysis of drugs that use traditional isolation techniques for sample preparation such as the protein precipitation method.

  14. Multi-elemental analysis of aqueous geological samples by inductively coupled plasma-optical emission spectrometry

    Science.gov (United States)

    Todorov, Todor I.; Wolf, Ruth E.; Adams, Monique

    2014-01-01

    Typically, 27 major, minor, and trace elements are determined in natural waters, acid mine drainage, extraction fluids, and leachates of geological and environmental samples by inductively coupled plasma-optical emission spectrometry (ICP-OES). At the discretion of the analyst, additional elements may be determined after suitable method modifications and performance data are established. Samples are preserved in 1–2 percent nitric acid (HNO3) at sample collection or as soon as possible after collection. The aqueous samples are aspirated into the ICP-OES discharge, where the elemental emission signals are measured simultaneously for 27 elements. Calibration is performed with a series of matrix-matched, multi-element solution standards.

  15. Automated suspension of washed erythrocytes in fresh-frozen plasma for exchange transfusion. Obtaining a desired hematocrit.

    Science.gov (United States)

    Wenk, R E; Masucol, E; Brewer, M K

    1981-01-01

    Stored red blood cells may be automatically saline washed and resuspended in fresh-frozen plasma to yield a final product with any hematocrit that is desired. The technique provides for rapid processing and issue of blood and minimal risk of contamination of the unit. Red blood cells are more readily available than whole blood, and their use, with fresh-frozen plasma, in exchange transfusion, provides similar advantages, including low potassium content and normal content of procoagulants and bilirubin binding capacity. The method of reconstruction is based on calculations that use empirically determined estimates of average hematocrit and specific gravity of red blood cells and the volumetric flow characteristics of a programmable IBM 2991 Blood Processor. Only the weight of the stored red blood cell unit is required as a measurement at the time of preparing the resuspended cells. Quality-control studies of the final hematocrit indicates a 2.4 per cent standard deviation from a target value of 55 per cent.

  16. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  17. Histopathological examination of nerve samples from pure neural leprosy patients: obtaining maximum information to improve diagnostic efficiency

    Directory of Open Access Journals (Sweden)

    Sérgio Luiz Gomes Antunes

    2012-03-01

    Full Text Available Nerve biopsy examination is an important auxiliary procedure for diagnosing pure neural leprosy (PNL. When acid-fast bacilli (AFB are not detected in the nerve sample, the value of other nonspecific histological alterations should be considered along with pertinent clinical, electroneuromyographical and laboratory data (the detection of Mycobacterium leprae DNA with polymerase chain reaction and the detection of serum anti-phenolic glycolipid 1 antibodies to support a possible or probable PNL diagnosis. Three hundred forty nerve samples [144 from PNL patients and 196 from patients with non-leprosy peripheral neuropathies (NLN] were examined. Both AFB-negative and AFB-positive PNL samples had more frequent histopathological alterations (epithelioid granulomas, mononuclear infiltrates, fibrosis, perineurial and subperineurial oedema and decreased numbers of myelinated fibres than the NLN group. Multivariate analysis revealed that independently, mononuclear infiltrate and perineurial fibrosis were more common in the PNL group and were able to correctly classify AFB-negative PNL samples. These results indicate that even in the absence of AFB, these histopathological nerve alterations may justify a PNL diagnosis when observed in conjunction with pertinent clinical, epidemiological and laboratory data.

  18. Histopathological examination of nerve samples from pure neural leprosy patients: obtaining maximum information to improve diagnostic efficiency.

    Science.gov (United States)

    Antunes, Sérgio Luiz Gomes; Chimelli, Leila; Jardim, Márcia Rodrigues; Vital, Robson Teixeira; Nery, José Augusto da Costa; Corte-Real, Suzana; Hacker, Mariana Andréa Vilas Boas; Sarno, Euzenir Nunes

    2012-03-01

    Nerve biopsy examination is an important auxiliary procedure for diagnosing pure neural leprosy (PNL). When acid-fast bacilli (AFB) are not detected in the nerve sample, the value of other nonspecific histological alterations should be considered along with pertinent clinical, electroneuromyographical and laboratory data (the detection of Mycobacterium leprae DNA with polymerase chain reaction and the detection of serum anti-phenolic glycolipid 1 antibodies) to support a possible or probable PNL diagnosis. Three hundred forty nerve samples [144 from PNL patients and 196 from patients with non-leprosy peripheral neuropathies (NLN)] were examined. Both AFB-negative and AFB-positive PNL samples had more frequent histopathological alterations (epithelioid granulomas, mononuclear infiltrates, fibrosis, perineurial and subperineurial oedema and decreased numbers of myelinated fibres) than the NLN group. Multivariate analysis revealed that independently, mononuclear infiltrate and perineurial fibrosis were more common in the PNL group and were able to correctly classify AFB-negative PNL samples. These results indicate that even in the absence of AFB, these histopathological nerve alterations may justify a PNL diagnosis when observed in conjunction with pertinent clinical, epidemiological and laboratory data.

  19. Autofluorescence in samples obtained from chronic biofilm infections – “all that glitters is not gold”

    DEFF Research Database (Denmark)

    Eickhardt-Dalbøge, Steffen Robert; Kragh, Kasper N.; Schrøder, Stine;

    2015-01-01

    When looking at tissue sections of ex vivo samples, autofluorescence can be a major cause of artifacts and misinterpretations. We here reiterate evidence that autofluorescing granules, often hemosiderin but also ceroid or mucinogen granules, are severe obstacles when imaging and diagnosing biofil...

  20. Biological investigations of Indian phaeophyceae: 17. Seasonal variation of antibacterial activity of total sterols obtained from frozen samples of Sargassum johnstonii Setchell et Gardner

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.P.S.

    From lipid fraction of frozen samples of Sargassum johnstonii unsaponifiable part was extracted with diethyl ether to isolate total sterols. The extracted sterols were obtained for a period of nine months and tested against test bacteria...

  1. XPS study of the corrosion resisting composite alloying layer obtained by double glow plasma with the brush plating Ni interlayer

    Institute of Scientific and Technical Information of China (English)

    Jiang Xu; Xishan Xie; Zhong Xu; Wenjin Liu

    2004-01-01

    The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brush plating Ni interlayer on the low carbon steel substrate has been investigated. By the electrochemical method in 3.5% (mass fraction) NaC1 solution, the corrosion resistance of the composite alloying layer and single alloying layer is determined. The experimental results show that the corrosion resistance of the composite alloying layer is obviously better than that of the single alloying layer. The structure and composition of passive films formed on the two kinds of alloyed layers after electrochemical tests in 3.5% NaC1 solution have been studied using X-ray photoelectron spectroscopy (XPS). It is concluded that the double glow plasma surface alloying of low carbon steel with the electric brush plating Ni interlayer is an appropriate technique to enhance the corrosion resistance compared with the single double glow surface alloying.

  2. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Juergen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aaron, A. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, Gary L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burgess, Thomas W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ellis, Ronald James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans, James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lessard, Timothy L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ohriner, Evan Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Perkins, Dale E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Varma, Venugopal Koikal [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-20

    -state heat fluxes of 5–20 MW/m2 and ion fluxes up to 1024 m-2s-1. Since PFCs will have to withstand neutron irradiation displacement damage up to 50 dpa, the target station design must accommodate radioactive specimens (materials to be irradiated in HFIR or at SNS) to enable investigations of the impact of neutron damage on materials. Therefore, the system will have to be able to install and extract irradiated specimens using equipment and methods to avoid sample modification, control contamination, and minimize worker dose. Included in the design considerations will be an assessment of all the steps between neutron irradiation and post-exposure materials examination/characterization, as well as an evaluation of the facility hazard categorization. In particular, the factors associated with the acquisition of radioactive specimens and their preparation, transportation, experimental configuration at the plasma-specimen interface, post-plasma-exposure sample handling, and specimen preparation will be evaluated.

  3. Direct trace-elemental analysis of urine samples by laser ablation-inductively coupled plasma mass spectrometry after sample deposition on clinical filter papers.

    Science.gov (United States)

    Aramendía, Maite; Rello, Luis; Vanhaecke, Frank; Resano, Martín

    2012-10-16

    Collection of biological fluids on clinical filter papers shows important advantages from a logistic point of view, although analysis of these specimens is far from straightforward. Concerning urine analysis, and particularly when direct trace elemental analysis by laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) is aimed at, several problems arise, such as lack of sensitivity or different distribution of the analytes on the filter paper, rendering obtaining reliable quantitative results quite difficult. In this paper, a novel approach for urine collection is proposed, which circumvents many of these problems. This methodology consists on the use of precut filter paper discs where large amounts of sample can be retained upon a single deposition. This provides higher amounts of the target analytes and, thus, sufficient sensitivity, and allows addition of an adequate internal standard at the clinical lab prior to analysis, therefore making it suitable for a strategy based on unsupervised sample collection and ulterior analysis at referral centers. On the basis of this sampling methodology, an analytical method was developed for the direct determination of several elements in urine (Be, Bi, Cd, Co, Cu, Ni, Sb, Sn, Tl, Pb, and V) at the low μg L(-1) level by means of LA-ICPMS. The method developed provides good results in terms of accuracy and LODs (≤1 μg L(-1) for most of the analytes tested), with a precision in the range of 15%, fit-for-purpose for clinical control analysis.

  4. Use of factorial design for evaluation of plasma conditions and comparison of two liquid sample introduction systems for an axially viewed inductively coupled plasma optical emission spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Trevizan, Lilian C. [Grupo de Analise Instrumental Aplicada, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, Sao Carlos, SP, 13650-970 (Brazil); Vieira, Edivan C. [Grupo de Analise Instrumental Aplicada, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, Sao Carlos, SP, 13650-970 (Brazil); Embrapa Pecuaria Sudeste, Sao Carlos, SP (Brazil); Nogueira, Ana Rita A. [Embrapa Pecuaria Sudeste, Sao Carlos, SP (Brazil); Nobrega, Joaquim A. [Grupo de Analise Instrumental Aplicada, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, Sao Carlos, SP, 13650-970 (Brazil)]. E-mail: djan@terra.com.br

    2005-06-30

    A factorial design was applied to evaluate plasma conditions employing the Mg II 280/Mg I 285 nm intensity ratio in an axially viewed inductively coupled plasma optical emission spectrometer using different sample introduction devices: a concentric or a V-groove nebulizer and a cyclonic or a Sturman-Masters spray chamber. Effects of nebulizer gas flow-rate on Mg II/Mg I ratio were different in each introduction system. Robust conditions were obtained at low nebulizer gas flow-rate when using concentric nebulizer with a cyclonic spray chamber or a concentric nebulizer and a Sturman-Masters spray chamber. However, when using a V-groove nebulizer with a Sturman-Masters spray chamber, Mg II/Mg I ratio increased at high nebulizer gas flow-rates. Recovery experiments for a milk standard reference material diluted in water-soluble tertiary amines in both robust and non-robust conditions indicated that the robust condition was reached at higher nebulizer gas flow-rates and led to better accuracy and precision when using a V-groove nebulizer.

  5. Development of a chromatographic method for the determination of saquinavir in plasma samples of HIV patients.

    Science.gov (United States)

    Campanero, M A; Escolar, M; Arangoa, M A; Sádaba, B; Azanza, J R

    2002-02-01

    A simple, sensitive and reproducible high-performance liquid chromatographic method for detecting and quantifying saquinavir in human plasma is described. Verapamil was used as internal standard. The method employes a single liquid-liquid extraction step with tert-butil methyl ether followed by chromatography on a Lichrospher 60 Select B C8 reversed-phase column. Ultraviolet detection was used to identify the compounds of interest. The quantitation limit of saquinavir was 1 ng/mL and only 0.5 mL of plasma sample was required for the determination. The average saquinavir recoveries over a concentration range of 2.5-500 ng/mL ranged from 86 to 95%. Precision and accuracy did not exceed 5%.

  6. Analysis of surface chemistry of boronized TZM samples in NSTX-U between plasma exposures

    Science.gov (United States)

    Schamis, Hanna; Bedoya, Felipe; Allain, Jean Paul; Kaita, Robert; Koel, Bruce

    2016-10-01

    In the National Spherical Torus Experiment Upgrade (NSTX-U) a new plasma facing component diagnostic, the Material Analysis and Particle Probe (MAPP), was installed. MAPP has the capability of conducting XPS studies on materials without exposing them to atmospheric conditions. MAPP was used to conduct XPS studies of TZM (99% Mo, 0.5% Ti, 0.08% Zr) samples. XPS gives information about the chemical composition of up to about 5 nm of the surface, and can be conducted on a day-to-day basis or at higher temporal resolutions e.g. close to in-between plasma shots. MAPP characterization gives insight on boron deposition and fuel retention by following the evolution of atomic concentrations and oxidation states. The data shows that the boron deposited layer was thicker than 5 nm. Additionally, the data shows evidence of sputtering of the boron layers following tens of plasma shots. The data also shows an increase in the oxygen concentration with plasma exposure. The next NSTX-U experimental campaign will feature TZM tiles in the lower divertor region, while the rest of the first wall will continue to be ATJ graphite. Our data provides the basis to analyze how the surface chemistry of the new set of tiles will be influenced by plasma operations, boron conditioning and carbon migration. Work supported by US DOE Contract No. DE-AC02-09CH11466, US DOE Contract No. DE-SC0010717, Award No. DE-SC0012890, and the DOE Science Undergraduate Laboratory Internship (SULI) Program.

  7. Comparison of two molecular assays for detection of cytomegalovirus DNA in whole blood and plasma samples from transplant recipients.

    Science.gov (United States)

    Costa, Cristina; Sidoti, Francesca; Mantovani, Samantha; Gregori, Gabriella; Proietti, Alex; Ghisetti, Valeria; Cavallo, Rossana

    2016-07-01

    In immunosuppressed patients, pre-emptive therapy and a strict follow-up of CMV infection are the standard of care for the prevention of CMV disease. Several real-time PCR assays for CMV DNA quantification on whole blood (WB) and plasma (PL) are commercially available. This study compared and correlated CMV viral loads obtained by the Cobas AmpliPrep/Cobas TaqMan (CAP/CTM) platform on plasma specimens with those obtained on corresponding whole blood specimens by the real-time PCR assay (ELITe MGB-CMV) in 185 sequential samples from 41 immunosuppressed patients. Correlation between the two assays was good. Kinetics of CMV DNA within the same patient was similar, but PL viral load was constantly 1 log lower than WB. In patients under antiviral therapy, low level of CMV DNA persisted in WB, while it was absent in PL. The good correlation between CMV DNA detected on both PL and WB supports the reliability of the two matrices for viral monitoring and the therapeutic management of CMV infection. Nevertheless, due to significant quantification differences between PL and WB CMV DNA, the same biological specimen should be used for a sequential and reliable follow-up of patients at high risk of CMV infection.

  8. An attempt to validate serum and plasma as sample matrices for analyses of polychlorobiphenylols

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, J.; Bergman, Aa. [Stockholm Univ. (Sweden). Dept. of Environmental Chemistry; Bignert, A. [Museum of Natural History (Sweden)

    2004-09-15

    Polychlorinated biphenyls (PCBs) form hydroxylated metabolites (OH-PCBs), as reported both from wildlife and from experimental animal studies already in the early 1970s'. However, the interest increased in OH-PCBs from the mid 1990s' depending on the discovery that some OHPCB congeners are strongly retained in the blood of birds, fish and mammals, including humans. The interest is linked to the fact that OH-PCBs is strongly, but reversibly, bound to the blood protein transthyretin (TTR). It is reasonable to believe that the strong TTR binding may have toxicological impact, probably related to endocrine type effects. Importantly, OH-PCBs are present in blood at far higher concentrations than in any other compartment in the body, which is dependent on the physico-chemical characteristics of the phenols. Analyses of OH-PCBs have thus been concentrated to whole blood, plasma or serum. Still there is no comparison between the three sample types even though it is clear that whole blood is not optimal due to the large proportion of haemoglobin in the sample that make the clean up more difficult than if plasma or serum is selected for analysis. In the present study we have addressed two questions: First we have looked at any potential differences in the analytical results of OH-PCBs when using serum and plasma for extraction and clean up; Second, the serum and plasma applied in the validation has been unfrozen, frozen (at -20 C) for two months and frozen for twenty months, respectively.

  9. Modulation of Cytokine mRNA Expression in Pharyngeal Epithelial Samples obtained from Cattle Infected with Foot-and-Mouth Disease Virus

    DEFF Research Database (Denmark)

    Stenfeldt, Anna Carolina; Heegaard, Peter M. H.; Stockmarr, Anders

    2012-01-01

    A novel technique of endoscopical collection of small tissue samples was used to obtain sequential tissue samples from the dorsal soft palate (DSP) of individual cattle infected with foot-and-mouth disease virus (FMDV) at different phases of the infection. Levels of mRNA encoding interferon (IFN...

  10. Determination of metals in composite diet samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Melnyk, Lisa Jo; Morgan, Jeffrey N; Fernando, Reshan; Pellizzari, Edo D; Akinbo, Olujide

    2003-01-01

    A study was conducted to evaluate the applicability of inductively coupled plasma-mass spectrometry (ICP-MS) techniques for determination of metals in composite diets. Aluminum, cadmium, chromium, copper, lead, manganese, nickel, vanadium, and zinc were determined by this method. Atmospheric pressure microwave digestion was used to solubilize analytes in homogenized composite diet samples, and this procedure was followed by ICP-MS analysis. Recovery of certified elements from standard reference materials ranged from 92 to 119% with relative standard deviations (RSDs) of 0.4-1.9%. Recovery of elements from fortified composite diet samples ranged from 75 to 129% with RSDs of 0-11.3%. Limits of detection ranged from 1 to 1700 ng/g; high values were due to significant amounts of certain elements naturally present in composite diets. Results of this study demonstrate that low-resolution quadrupole-based ICP-MS provides precise and accurate measurements of the elements tested in composite diet samples.

  11. Maternal red blood cell alloantibodies identified in blood samples obtained from Iranian pregnant women: the first population study in Iran.

    Science.gov (United States)

    Shahverdi, Ehsan; Moghaddam, Mostafa; Gorzin, Fateme

    2017-01-01

    The objective was to determine the frequency of occurrence of alloantibodies among pregnant women in Iran. This was a prospective cross-sectional study, which was carried out in the immunohematology reference laboratory of the Iranian Blood Transfusion Organization in Tehran, Iran, in 2008 to 2015. Screening and identification of red blood cell (RBC) alloantibodies was done on the sera of 7340 pregnant females using the standard tube method and gel column agglutination technique. Alloantibodies were identified in the serum of 332 of the 7340 (4.5%) pregnant women. A total of 410 antibodies were detected in 332 positive maternal serum samples with no previous history of blood transfusion. Anti-D was the most common antibody accounting for 70.5% of all the antibodies formed in D- women. The incidence of specific alloimmunization other than Rh group was 14.4%. We concluded that the alloimmunization rate was high in comparison with wide pattern in previous studies. In Iran, like other developing countries, alloimmunization screening tests are performed only to detect anti-D in pregnant D- women. This high rate of alloimmunization, quite possibly, is due to the fact that the majority of blood samples came from pregnant women known to have previous obstetric problems. However, we suggest that RBC antibody screening tests should be extended to all D+ women. © 2016 AABB.

  12. Determination of noble metals in biological samples by electrothermal vaporization inductively coupled plasma mass spectrometry, following cloud point extraction

    Science.gov (United States)

    Andreia Mesquita da Silva, Márcia; Lúcia Azzolin Frescura, Vera; José Curtius, Adilson

    2001-10-01

    A simple separation procedure for noble metals based on cloud point extraction is proposed. The analyte ions in aqueous acidic solution, obtained by the acid digestion of the samples, were complexed with O, O-diethyl-dithiophosphate and Triton X-114 was added as a non-ionic surfactant. By increasing the temperature up to the cloud point, a phase separation occurs, resulting in an aqueous phase and a surfactant-rich phase containing most of the analytes that were complexed. The metals in the surfactant-rich phase were determined by electrothermal vaporization inductively coupled plasma mass spectrometry. The extraction conditions as well as the instrumental parameters were optimized. Enrichment factors ranging from 7 (Rh) to 60 (Pt) and limits of detection from 0.6 (Pt) to 3.0 ng l -1 (Rh) were obtained in the digested samples. The extraction was not efficient for Ir. Among the reference materials analyzed in this work, only one (SRM 2670, urine) presented recommended values for Au and Pt. Due to the non-availability of adequate CRMs, accuracy was assessed by spiking known analyte amounts to the acid digests. Recoveries close to 100% were observed for all the studied elements but Ru. Poor agreement between found and recommended values was observed for non-digested urine sample, probably due to the carrier effect of co-extracted residual matrix components. However, good agreement was reached after urine acid mineralization.

  13. Observation of asymmetrically imploded core plasmas with a two-dimensional sampling image x-ray streak camera.

    Science.gov (United States)

    Shiraga, Hiroyuki; Lee, Myongdok; Mahigashi, Norimitsu; Fujioka, Shinsuke; Azechi, Hiroshi

    2008-10-01

    A shell target with a cone for guiding the heating beam has been proposed for the fast ignition scheme. Implosion of such target is no longer symmetric because of the cone. A fast two-dimensional x-ray imaging technique, two-dimensional (2D) sampling image x-ray streak camera was applied for the first time to observation of the dynamics of implosion and core plasma. X-ray emission image of the plasma was sampled with two-dimensionally distributed image sampling points, streaked with the tube, and the recorded signals were reconstructed as sequential 2D frame images. Shape and movement of the core plasma were clearly observed.

  14. Determination of the neutral oxygen atom density in a plasma reactor loaded with metal samples

    Energy Technology Data Exchange (ETDEWEB)

    Mozetic, Miran; Cvelbar, Uros [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia)], E-mail: miran.mozetic@ijs.si

    2009-08-15

    The density of neutral oxygen atoms was determined during processing of metal samples in a plasma reactor. The reactor was a Pyrex tube with an inner diameter of 11 cm and a length of 30 cm. Plasma was created by an inductively coupled radiofrequency generator operating at a frequency of 27.12 MHz and output power up to 500 W. The O density was measured at the edge of the glass tube with a copper fiber optics catalytic probe. The O atom density in the empty tube depended on pressure and was between 4 and 7 x 10{sup 21} m{sup -3}. The maximum O density was at a pressure of about 150 Pa, while the dissociation fraction of O{sub 2} molecules was maximal at the lowest pressure and decreased with increasing pressure. At about 300 Pa it dropped below 10%. The measurements were repeated in the chamber loaded with different metallic samples. In these cases, the density of oxygen atoms was lower than that in the empty chamber. The results were explained by a drain of O atoms caused by heterogeneous recombination on the samples.

  15. Determination by high-performance liquid chromatography of phenylbutazone in samples of plasma from fighting bulls.

    Science.gov (United States)

    Marti, M I González; Sánchez, González C I; Jiménez, Hernández; Cachán, García; Castro, de Cabo M J; Cuadrado, A L Garzón

    2002-03-25

    The purpose of this study was to investigate the possible presence of phenylbutazone in plasma samples from fighting bulls killed in 2nd and 3rd category bullrings in the province of Salamanca (Spain) in 1998, 1999 and 2000. For quantitative and qualitative determination, a high-performance liquid chromatograph was used, equipped with a photodiode-array detector and setting wavelengths at 240, 254 and 284 nm. The mobile phase optimized for the simultaneous detection of dexamethasone, betamethasone, flunixin and phenylbutazone, was 0.01 M acetic acid pH 3 in methanol (35:65 v/v) at a flow rate of 1 ml/min. Plasma samples were deproteinized with 400 microl of acetonitrile and 20 microl of the supernatant were injected directly into the chromatographic system equipped with a Lichrospher 60 RP select B column and guard column. For the quantitative analysis, standard calibration curves were made in a concentration range between 0.25 and 30 microg/ml, using betamethasone as internal standard. The retention time of phenylbutazone was 8.7 +/- 0.2 min and recovery was 83%. The detection and quantification limits were 0.016 and 0.029, respectively for A=240 nm. The study results show that 17 of the 74 samples analyzed in 1998, 18 of those from 1999 and 10 of those from 2000 were positive for phenylbutazone.

  16. Etching of Niobium Sample Placed on Superconducting Radio Frequency Cavity Surface in Ar/CL2 Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Janardan Upadhyay, Larry Phillips, Anne-Marie Valente

    2011-09-01

    Plasma based surface modification is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. It has been proven with flat samples that the bulk Niobium (Nb) removal rate and the surface roughness after the plasma etchings are equal to or better than wet etching processes. To optimize the plasma parameters, we are using a single cell cavity with 20 sample holders symmetrically distributed over the cell. These holders serve the purpose of diagnostic ports for the measurement of the plasma parameters and for the holding of the Nb sample to be etched. The plasma properties at RF (100 MHz) and MW (2.45 GHz) frequencies are being measured with the help of electrical and optical probes at different pressures and RF power levels inside of this cavity. The niobium coupons placed on several holders around the cell are being etched simultaneously. The etching results will be presented at this conference.

  17. Macro- and micro-element analysis in milk samples by inductively coupled plasma-optical emission spectrometry

    Directory of Open Access Journals (Sweden)

    Petrović Sanja M.

    2016-01-01

    Full Text Available The paper describes the determination of Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, In, K, Li, Mg, Mn, Na, Ni, Pb, Sr, Tl and Zn, as well as total fat content of milk samples, originated from different sources. The analyzed milk samples were: human milk, fresh cow milk, pasteurized cow milk from a local market, and reconstituted powder milk. The milk samples were obtained from Jablanica District (Serbia territory. Preparation of samples for macro- and micro-analyses was done by wet digestion. Concentrations of the elements after digestion were determined by inductively coupled plasma optical emission spectrometry (ICP-OES. Total fat content of milk samples was determinate by the Weibull and Stoldt method. The results showed that potassium and calcium concentrations were the highest in all samples: 1840.64 - 2993.26 mg/L and 456.05 - 1318.08 mg/L, respectively. Of all heavy metals from the examined milk samples (copper, zinc, manganese, nickel, cadmium, and lead, the most common were zinc and copper, with approximately similar content in the range of 5 - 12 mg/l, while cadmium nickel and manganese were not detected at all. Samples of fresh cow milk and human milk showed the highest fat content of 3.6 and 4.2 %, respectively. Results for total fat and macro- and micro-analyses showed that fresh cow milk has the highest contents of fat and calcium, making it the most nutritious. [Projekat Ministarstva nauke Republike Srbije, br. TR 34012

  18. Multielement determination of heavy metals in water samples by continuous powder introduction microwave-induced plasma atomic emission spectrometry after preconcentration on activated carbon

    Science.gov (United States)

    Jankowski, Krzysztof; Yao, Jun; Kasiura, Krzysztof; Jackowska, Adrianna; Sieradzka, Anna

    2005-03-01

    A novel continuous powder introduction microwave-induced plasma atomic emission spectrometry method (CPI-MIP-AES) has been developed for trace determination of metals in ground and tap water samples after preconcentration on activated carbon. The experimental setup consisted of integrated rectangular cavity TE 101 and vertically positioned plasma torch. The technical arrangement of the sample introduction system has been designed based on the fluidized bed concept. The satisfactory signal stability required for sequential analysis was attained owing to the vertical plasma configuration, as well as the plasma gas flow rate compatibility with sample introduction flow rate. The elements of interest (Cd, Cu, Cr, Fe, Mn, Pb, Zn) were preconcentrated in a batch procedure at pH 8-8.5 after addition of activated carbon and then, after filtering and drying of the activated carbon suspension, introduced to the MIP by the CPI system. An enrichment factor of about 1000-fold for a sample volume of 1 l was obtained. The detection limit values for the proposed method were 17-250 ng l -1. The proposed method was validated by analyzing the certified reference materials: SRW "Warta" Synthetic River Water and BCR CRM 399 major elements in freshwater. The method was successfully applied to the determination of the heavy metals in tap water samples.

  19. Multielement determination of heavy metals in water samples by continuous powder introduction microwave-induced plasma atomic emission spectrometry after preconcentration on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Krzysztof [Warsaw University of Technology, Faculty of Chemistry, Department of Analytical Chemistry, 00-664 Warsaw, ul. Noakowskiego 3 (Poland)]. E-mail: kj@ch.pw.edu.pl; Yao Jun [College of Chemistry and Chemical Engineering, Jishou University, 120 Renmin South Road, Jishou 416000 (China); Kasiura, Krzysztof [Warsaw University of Technology, Faculty of Chemistry, Department of Analytical Chemistry, 00-664 Warsaw, ul. Noakowskiego 3 (Poland); Jackowska, Adrianna [Warsaw University of Technology, Faculty of Chemistry, Department of Analytical Chemistry, 00-664 Warsaw, ul. Noakowskiego 3 (Poland); Sieradzka, Anna [Warsaw University of Technology, Faculty of Chemistry, Department of Analytical Chemistry, 00-664 Warsaw, ul. Noakowskiego 3 (Poland)

    2005-03-31

    A novel continuous powder introduction microwave-induced plasma atomic emission spectrometry method (CPI-MIP-AES) has been developed for trace determination of metals in ground and tap water samples after preconcentration on activated carbon. The experimental setup consisted of integrated rectangular cavity TE{sub 101} and vertically positioned plasma torch. The technical arrangement of the sample introduction system has been designed based on the fluidized bed concept. The satisfactory signal stability required for sequential analysis was attained owing to the vertical plasma configuration, as well as the plasma gas flow rate compatibility with sample introduction flow rate. The elements of interest (Cd, Cu, Cr, Fe, Mn, Pb, Zn) were preconcentrated in a batch procedure at pH 8-8.5 after addition of activated carbon and then, after filtering and drying of the activated carbon suspension, introduced to the MIP by the CPI system. An enrichment factor of about 1000-fold for a sample volume of 1 l was obtained. The detection limit values for the proposed method were 17-250 ng l{sup -1}. The proposed method was validated by analyzing the certified reference materials: SRW 'Warta' Synthetic River Water and BCR CRM 399 major elements in freshwater. The method was successfully applied to the determination of the heavy metals in tap water samples.

  20. Quartz crystal microbalance for the cardiac markers/antibodies binding kinetic measurements in the plasma samples

    Science.gov (United States)

    Agafonova, L. E.; Shumyantseva, V. V.; Archakov, A. I.

    2014-06-01

    The quartz crystal microbalance (QCM) was exploited for cardiac markers detection and kinetic studies of immunochemical reaction of cardiac troponin I (cTnI) and human heart fatty acid binding protein (H-FABP) with the corresponding monoclonal antibodies in undiluted plasma (serum) and standard solutions. The QCM technique allowed to dynamically monitor the kinetic differences in specific interactions and nonspecific sorption, without multiple labeling procedures and separation steps. The affinity binding process was characterized by the association (ka) and the dissociation (kd) kinetic constants and the equilibrium association (K) constant, all of which were obtained from experimental data.

  1. Automated processing of whole blood samples into microliter aliquots of plasma

    OpenAIRE

    1988-01-01

    A rotor that accepts and automatically processes a bulk aliquot of a single blood sample into multiple aliquots of plasma has been designed and built. The rotor consists of a central processing unit, which includes a disk containing eight precision-bore capillaries. By varying the internal diameters of the capillaries, aliquot volumes ranging 1 to 10 μl can be prepared. In practice, an unmeasured volume of blood is placed in a centre well, and, as the rotor begins to spin, is moved radially i...

  2. Thermal barrier ZrO2 - Y2O3 obtained by plasma spraying method and laser melting

    Directory of Open Access Journals (Sweden)

    K. Kobylańska–Szkaradek

    2006-04-01

    Full Text Available Purpose: Purpose: The aim of the paper is to determine the influence of laser melting upon the selected physical properties of ZrO2 - Y2O3 ceramic coatings deposited by APS (Air Plasma Spraying method on super-alloys which function as TBC (Thermal Barriers Coatings.Design/methodology/approach: Laser melting which helps eliminate pores and other structural defects of coatings should contribute to the improvement of their density and durability as thermal barriers. In order to prove the assumptions made in the paper, coatings featuring varied porosity and deposited upon the nickel base super-alloys surface with the initially sprayed NiCrAlY bond coat have been subjected to laser melting and then their structure, thermal conductivity and thermal life prediction in the conditions of cyclic temperature changes from 20 to 1200ºC have been examined.Findings: It has been revealed that the coatings featuring low porosity laser melted on part of their thickness and heated up to about 700ºC demonstrate the highest thermal life prediction under the conditions mentioned and at slightly lower thermal conductivity.Research limitations/implications: Low wettability of metal by ceramic which results from various surface tensions of these materials is the cause of their lower adhesion to the substrate during laser melting all through their thickness. It is so because delaminations occur between phases the boundary and cracks.Practical implications: The worked out conditions of laser melting might be used in the process of creation of TBC which feature high working durability upon super-alloy elements.Originality/value: It has been found that homogenization of chemical composition of coatings occurs during laser melting leading to the reduction of ZrO2 - Y2O3 phase with monoclinic lattice participation as well as to the reduction of structural stresses which accompany this phase transformation during heating and cooling process.

  3. Oxygen bomb combustion of biological samples for inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    Souza, Gilberto B.; Carrilho, Elma Neide V. M.; Oliveira, Camila V.; Nogueira, Ana Rita A.; Nóbrega, Joaquim A.

    2002-12-01

    A rapid sample preparation method is proposed for decomposition of milk powder, corn bran, bovine and fish tissues, containing certified contents of the analytes. The procedure involves sample combustion in a commercial stainless steel oxygen bomb operating at 25 bar. Most of the samples were decomposed within 5 min. Diluted nitric acid or water-soluble tertiary amines 10% v/v were used as absorption solutions. Calcium, Cu, K, Mg, Na, P, S and Zn were recovered with the bomb washings and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Ethanol mixed with paraffin was used as a combustion aid to allow complete combustion. A cooling step prior releasing of the bomb valve was employed to increase the efficiency of sample combustion. Iodine was also determined in milk samples spiked with potassium iodide to evaluate the volatilization and collection of iodine in amine CFA-C medium and the feasibility of its determination by ICP-OES with axial view configuration. Most of the element recoveries in the samples were between 91 and 105% and the certified and found contents exhibited a fair agreement at a 95% confidence level.

  4. Measurement of glomerular filtration rate in adults: accuracy of five single-sample plasma clearance methods

    DEFF Research Database (Denmark)

    Rehling, M; Rabøl, A

    1989-01-01

    After an intravenous injection of a tracer that is removed from the body solely by filtration in the kidneys, the glomerular filtration rate (GFR) can be determined from its plasma clearance. The method requires a great number of blood samples but collection of urine is not needed. In the present......-acetate) was determined simultaneously. Using these clearance values as reference the accuracy of six simplified methods were studied: five single-sample methods and one five-sample method. The standard error of estimate (SEE) of the single-sample methods ranged from 4.2 to 7.5 ml min-1 using EDTA, and from 3.8 to 6.3 ml...... min-1 using DTPA. SEE of the five-samples method was 3.0 ml min-1 (EDTA) and 3.1 ml min-1 (DTPA). The single-sample methods given by Christensen & Groth (1986) and by Tauxe (1986) are recommended for daily use, as SEE was small even at low GFR values. In patients with GFR less than 80 ml min-1...

  5. Effects of Long-Term Storage Time and Original Sampling Month on Biobank Plasma Protein Concentrations.

    Science.gov (United States)

    Enroth, Stefan; Hallmans, Göran; Grankvist, Kjell; Gyllensten, Ulf

    2016-10-01

    The quality of clinical biobank samples is crucial to their value for life sciences research. A number of factors related to the collection and storage of samples may affect the biomolecular composition. We have studied the effect of long-time freezer storage, chronological age at sampling, season and month of the year and on the abundance levels of 108 proteins in 380 plasma samples collected from 106 Swedish women. Storage time affected 18 proteins and explained 4.8-34.9% of the observed variance. Chronological age at sample collection after adjustment for storage-time affected 70 proteins and explained 1.1-33.5% of the variance. Seasonal variation had an effect on 15 proteins and month (number of sun hours) affected 36 proteins and explained up to 4.5% of the variance after adjustment for storage-time and age. The results show that freezer storage time and collection date (month and season) exerted similar effect sizes as age on the protein abundance levels. This implies that information on the sample handling history, in particular storage time, should be regarded as equally prominent covariates as age or gender and need to be included in epidemiological studies involving protein levels.

  6. 33S nuclear magnetic resonance spectroscopy of biological samples obtained with a laboratory model 33S cryogenic probe.

    Science.gov (United States)

    Hobo, Fumio; Takahashi, Masato; Saito, Yuta; Sato, Naoki; Takao, Tomoaki; Koshiba, Seizo; Maeda, Hideaki

    2010-05-01

    (33)S nuclear magnetic resonance (NMR) spectroscopy is limited by inherently low NMR sensitivity because of the quadrupolar moment and low gyromagnetic ratio of the (33)S nucleus. We have developed a 10 mm (33)S cryogenic NMR probe, which is operated at 9-26 K with a cold preamplifier and a cold rf switch operated at 60 K. The (33)S NMR sensitivity of the cryogenic probe is as large as 9.8 times that of a conventional 5 mm broadband NMR probe. The (33)S cryogenic probe was applied to biological samples such as human urine, bile, chondroitin sulfate, and scallop tissue. We demonstrated that the system can detect and determine sulfur compounds having SO(4)(2-) anions and -SO(3)(-) groups using the (33)S cryogenic probe, as the (33)S nuclei in these groups are in highly symmetric environments. The NMR signals for other common sulfur compounds such as cysteine are still undetectable by the (33)S cryogenic probe, as the (33)S nuclei in these compounds are in asymmetric environments. If we shorten the rf pulse width or decrease the rf coil diameter, we should be able to detect the NMR signals for these compounds.

  7. Quantitative analysis of Tenecteplase in rat plasma samples using LC-MS/MS as an alternative for ELISA

    NARCIS (Netherlands)

    Buscher, B.A.P.; Gerritsen, H.; Schöll, I. van; Cnubben, N.H.P.; Brüll, L.P.

    2007-01-01

    An LC-MS/MS method has been developed for the quantitative determination of a protein drug (Tenecteplase; MW 58,777 Da) in rat plasma. The protein was digested with trypsin without prior clean-up of the plasma sample, without the use of a label nor internal standard. A limited validation was perform

  8. Quantitative analysis of Tenecteplase in rat plasma samples using LC-MS/MS as an alternative for ELISA

    NARCIS (Netherlands)

    Buscher, B.A.P.; Gerritsen, H.; Schöll, I. van; Cnubben, N.H.P.; Brüll, L.P.

    2007-01-01

    An LC-MS/MS method has been developed for the quantitative determination of a protein drug (Tenecteplase; MW 58,777 Da) in rat plasma. The protein was digested with trypsin without prior clean-up of the plasma sample, without the use of a label nor internal standard. A limited validation was perform

  9. Determination of dimethyltryptamine and β-carbolines (ayahuasca alkaloids) in plasma samples by LC-MS/MS.

    Science.gov (United States)

    Oliveira, Carolina Dizioli Rodrigues; Okai, Guilherme Gonçalves; da Costa, José Luiz; de Almeida, Rafael Menck; Oliveira-Silva, Diogo; Yonamine, Mauricio

    2012-07-01

    Ayahuasca is a psychoactive plant beverage originally used by indigenous people throughout the Amazon Basin, long before its modern use by syncretic religious groups established in Brazil, the USA and European countries. The objective of this study was to develop a method for quantification of dimethyltryptamine and β-carbolines in human plasma samples. The analytes were extracted by means of C18 cartridges and injected into LC-MS/MS, operated in positive ion mode and multiple reaction monitoring. The LOQs obtained for all analytes were below 0.5 ng/ml. By using the weighted least squares linear regression, the accuracy of the analytical method was improved at the lower end of the calibration curve (from 0.5 to 100 ng/ml; r(2)> 0.98). The method proved to be simple, rapid and useful to estimate administered doses for further pharmacological and toxicological investigations of ayahuasca exposure.

  10. Comparison of the Cytobrush®, dermatological curette and oral CDx® brush test as methods for obtaining samples of RNA for molecular analysis of oral cytology.

    Science.gov (United States)

    Reboiras-López, M D; Pérez-Sayáns, M; Somoza-Martín, J M; Gayoso-Diz, P; Barros-Angueira, F; Gándara-Rey, J M; García-García, A

    2012-06-01

    Interest in oral exfoliative cytology has increased with the availability of molecular markers that may lead to the earlier diagnosis of oral squamous cell carcinoma. This research aims to compare the efficacy of three different instruments (Cytobrush, curette and Oral CDx brush) in providing adequate material for molecular analysis. One hundred and four cytological samples obtained from volunteer healthy subjects were analysed using all three instruments. The clinical and demographical variables under study were age, sex and smoking habits. The three instruments were compared for their ability to obtain adequate samples and for the amount of RNA obtained using quantitative real-time polymerase chain reaction (PCR-qRT) analysis of the Abelson (ABL) housekeeping gene. RNA of the ABL gene has been quantified by number of copies. Adequate samples were more likely to be obtained with a curette (90.6%) or Oral CDx (80.0%) than a Cytobrush (48.6%); P exfoliative cytology is a simple, non-invasive technique that provides sufficient RNA to perform studies on gene expression. Although material was obtained with all three instruments, adequate samples were more likely to be obtained with the curette or Oral CDx than with a Cytobrush. The Oral CDx is a less aggressive instrument than the curette, so could be a useful tool in a clinical setting. © 2011 Blackwell Publishing Ltd.

  11. Synthesis and characterization of cBN/WCCo composites obtained by the pulse plasma sintering (PPS) method

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, A; Rosinski, M; Plocinska, M; Szawlowski, J, E-mail: mihalski@inmat.pw.edu.pl [Warsaw University of Technology, Faculty of Materials Science and Engineering, Warsaw (Poland)

    2011-10-29

    The cBN/cemented carbide containing 30vol% of cBN particles was produced using a mixture of a 6wt% Co added-WC powder, with a WC grain size of 0.4 {mu}m and a cBN powder with a grain size ranging from 4 to 40 {mu}m. The mixture was sintered to produce a plate, 20 mm in diameter, 3 mm thick. The sintering processes were conducted at temperature of 1100 deg. C under a load of 100 MPa. The phase composition, density, hardness and micro structure of the sintered parts thus obtained were examined. The fractures through the WCCo/cBN composite showed the cBN particles torn out from the cemented carbide matrix were only few, whereas most of them have cleaved along the fracture plane. This gives evidence that the bond at the WCCo/cBN interface is mechanically strong.

  12. Characteristics of the equatorial plasma drifts as obtained by using Canadian Doppler ionosonde over southern tip of India

    Science.gov (United States)

    Sripathi, S.; Singh, Ram; Banola, S.; Sreekumar, Sreeba; Emperumal, K.; Selvaraj, C.

    2016-08-01

    We present here characteristics of the Doppler drift measurements over Tirunelveli (8.73°N, 77.70°E; dip 0.5°N), an equatorial site over Southern India using Doppler interferometry technique of Canadian ionosonde. Three-dimensional bulk motions of the scatterers as reflected from the ionosphere are derived by using Doppler interferometry technique at selected frequencies using spaced receivers arranged in magnetic E-W and N-S directions. After having compared with Lowell's digisonde drifts at Trivandrum, we studied the temporal and seasonal variabilities of quiet time drifts for the year 2012. The observations showed higher vertical drifts during post sunset in the equinox followed by winter and summer seasons. The comparison of Doppler vertical drifts with the drifts obtained from (a) virtual height and (b) Fejer drift model suggests that Doppler vertical drifts are relatively higher as compared to the drifts obtained from model and virtual height methods. Further, it is seen that vertical drifts exhibited equinoctial asymmetry in prereversal enhancement quite similar to such asymmetry observed in the spread F in the ionograms and GPS L band scintillations. The zonal drifts, on the other hand, showed westward during daytime with mean drifts of ~150-200 m/s and correlated well with equatorial electrojet strength indicating the role of E region dynamo during daytime, while they are eastward during nighttime with mean drifts of ~100 m/s resembling F region dynamo process. Also, zonal drifts showed large westward prior to the spread F onset during autumn equinox than vernal equinox, suggesting strong zonal shears which might cause equinoctial asymmetry in spread F.

  13. Aqueous two phase system based on ionic liquid for isolation of quinine from human plasma sample.

    Science.gov (United States)

    Flieger, J; Czajkowska-Żelazko, A

    2015-01-01

    Aqueous two phase system was applied for selective extraction of quinine from human plasma. Bi-phase was constructed from ionic liquid: butyl-methyl-imidazolium chloride after addition kosmotropic salts K₃PO₄ or KH₂PO₄. Quinine was determined in plasma samples after drinking of tonic containing quinine. Determination was performed by HPLC on 5-μm Zorbax SB-CN column and eluent containing 40% acetonitrile (v/v), 20 mM phosphate buffer at pH 3 and 40 mM NaPF₆ using external standard method. The spectrophotometric detection was set λ=214 nm. Selective fluorescence detection was performed at excitation of 325 nm and emission of 375 nm. Proposed strategy provides suitable sample purification and gives extraction yields in the range of 89-106%. The determination coefficient (R(2)) has a value ≥0.997 in the range of 50-800 ng/ml quinine concentration. The limit of quantification was set at 27.9 ng/ml and the detection limit was found to be 8.4 ng/ml under fluorescence detection.

  14. Catecholamines in plasma from artery, cubital vein, and femoral vein in patients with cirrhosis. Significance of sampling site

    DEFF Research Database (Denmark)

    Henriksen, J H; Ring-Larsen, H; Christensen, N J

    1986-01-01

    The concentration of noradrenaline (NA) and adrenaline (A) was measured in arterial, cubital venous and femoral venous plasma in order to determine possible differences in different vascular beds in the peripheral circulation. In patients with cirrhosis, arterial plasma NA (median 2.54 nmol/l, n ...... the skin of forearm and hand). To assess circulating levels of catecholamines, the importance of arterial sampling is stressed as peripheral venous samples may also reflect local factors....

  15. High-k gadolinium scandate on Si obtained by high pressure sputtering from metal targets and in-situ plasma oxidation

    Science.gov (United States)

    Pampillón, M. A.; San Andrés, E.; Feijoo, P. C.; Fierro, J. L. G.

    2017-03-01

    This article studies the physical and electrical behavior of Gd2‑x Sc x O3 layers grown by high pressure sputtering from metallic Gd and Sc targets. The aim is to obtain a high permittivity dielectric for microelectronic applications. The films were obtained by the deposition of a metallic nanolaminate of Gd and Sc alternating layers, which is afterwards in-situ oxidized by plasma. The oxide films obtained were close to stoichiometry, amorphous and with minimal interfacial regrowth. By fabricating metal–insulator–semiconductor capacitors we found that a moderate temperature annealing is needed to enhance permittivity, which reaches a high value of 32 while keeping moderate leakage. Finally, the feasibility of interface scavenging in this material with Ti gate electrodes is also demonstrated.

  16. Molecularly imprinted polymers based on SBA-15 for selective solid-phase extraction of baicalein from plasma samples.

    Science.gov (United States)

    He, Hongliang; Gu, Xiaoli; Shi, Liying; Hong, Junli; Zhang, Hongjuan; Gao, Yankun; Du, Shuhu; Chen, Lina

    2015-01-01

    Highly selective molecularly imprinted mesoporous silica polymer (SBA-15@MIP) for baicalein (BAI) extraction was synthesized using a surface molecular imprinting technique on the SBA-15 supporter. Computational simulation was used to predict the optimal functional monomer for the rational design of SBA-15@MIP. Meanwhile, high adsorption capacity was obtained when a suitable yield of molecularly imprinted polymers (MIPs) layer was grafted onto the surface of SBA-15. Characterization and performance tests of the obtained polymer revealed that SBA-15@MIP possessed a highly ordered mesoporous structure, reached saturated adsorption within 60 min, and exhibited higher sorption capacity to the target molecule BAI compared with non-imprinted mesoporous silica polymer (SBA-15@NIP) and SBA-15. Finally, SBA-15@MIP was successfully applied to solid-phase extraction (SPE) coupled with high-performance liquid chromatography and ultraviolet detection (HPLC-UV) for the determination of trace BAI in plasma samples. Mean recoveries of BAI through the molecularly imprinted solid-phase extraction (MISPE) sorbent, non-imprinted solid-phase extraction (NISPE) sorbent, and SBA-15 solid-phase extraction (SBA-15-SPE) sorbent were 94.4, 22.7, and 10.7 %, respectively, and the relative standard deviations were 2.9, 2.6, and 3.6 %, respectively. These results reveal that SBA-15@MIP as a SPE sorbent has good applicability to selectively separate and enrich trace BAI from complex samples.

  17. Quantitative analysis of Tenecteplase in rat plasma samples using LC-MS/MS as an alternative for ELISA.

    Science.gov (United States)

    Buscher, B A P; Gerritsen, H; van Schöll, I; Cnubben, N H P; Brüll, L P

    2007-06-01

    An LC-MS/MS method has been developed for the quantitative determination of a protein drug (Tenecteplase; M(W) 58,777 Da) in rat plasma. The protein was digested with trypsin without prior clean-up of the plasma sample, without the use of a label nor internal standard. A limited validation was performed to assess the linearity, the sensitivity and the specificity of the method. In addition, the developed method was applied to the quantitative analysis of Tenecteplase in rat plasma samples originating from a single-dose study in rats.

  18. Studies of lithium deposition and D retention on tungsten samples exposed to Li-seeded plasmas in PISCES-A

    Science.gov (United States)

    Tabarés, F. L.; Alegre, D.; Baldwin, M.; Nishijima, D.; Simmonds, M.; Doerner, R.; Alves, E.; Mateus, R.

    2017-04-01

    The interaction between lithium-seeded deuterium plasmas and tungsten targets has been studied in the PISCES-A divertor plasma simulator. Tungsten samples, of ITER-grade, with a diameter of 25 and 2 mm thick, were held at temperatures ranging from 403 to 873 K and exposed to Li/D plasmas under different plasma conditions and fixed total fluences of 5 ×1025 m‑2, with typical particle flux values of (1–5) × 1022 m‑2 s‑1. The deuterium and lithium contents of the samples after irradiation were analyzed by thermal desorption spectroscopy and nuclear reaction analysis (NRA). No lithium deposition was found within the sensitivity range of NRA, except for the cold (403 K) sample on which a layer with Li atomic density below 2 × 1022 m‑2 was detected. Deuterium retention values in the range of 1018 m‑2 were measured, even for the Li deposition conditions.

  19. A Movable Mass Spectroscopy Sampling Apparatus for Measuring Spatial Distribution of Neutral Radicals in Silane Plasma

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao-Kui; LIN Kui-Xun; LIN Xuan-Ying; QIU Gui-Ming; ZHU Zu-Song

    2005-01-01

    @@ A movable mass spectroscopy gas sampling apparatus has been established and a straight-line fit ofsilane depletion fraction f is proposed.The spatial density distributions of SiHn (n = 0-3) radicals in silane radio frequency glow discharge have been measured by a mass spectrometer.The experimental results demonstrate that the densities of the neutral radicals have the peak value near the middle position of electrodes, and the densities of SiH2 and SiHs are higher than those of Si and SiH in silane plasma.This reveals that SiH2 and SiH3 may be the primary precursors in forming the a-Si:H film.

  20. Platelet-Rich Plasma Obtained with Different Anticoagulants and Their Effect on Platelet Numbers and Mesenchymal Stromal Cells Behavior In Vitro

    Directory of Open Access Journals (Sweden)

    Ronaldo José Farias Corrêa do Amaral

    2016-01-01

    Full Text Available There are promising results in the use of platelet-rich plasma (PRP for musculoskeletal tissue repair. However, the variability in the methodology for its obtaining may cause different and opposing findings in the literature. Particularly, the choice of the anticoagulant is the first definition to be made. In this work, blood was collected with sodium citrate (SC, ethylenediaminetetraacetic acid (EDTA, or anticoagulant citrate dextrose (ACD solution A, as anticoagulants, prior to PRP obtaining. Hematological analysis and growth factors release quantification were performed, and the effects on mesenchymal stromal cell (MSC culture, such as cytotoxicity and cell proliferation (evaluated by MTT method and gene expression, were evaluated. The use of EDTA resulted in higher platelet yield in whole blood; however, it induced an increase in the mean platelet volume (MPV following the blood centrifugation steps for PRP obtaining. The use of SC and ACD resulted in higher induction of MSC proliferation. On the other hand, PRP obtained in SC presented the higher platelet recovery after the blood first centrifugation step and a minimal change in MSC gene expression. Therefore, we suggest the use of SC as the anticoagulant for PRP obtaining.

  1. Platelet-Rich Plasma Obtained with Different Anticoagulants and Their Effect on Platelet Numbers and Mesenchymal Stromal Cells Behavior In Vitro

    Science.gov (United States)

    do Amaral, Ronaldo José Farias Corrêa; da Silva, Nemias Pereira; Haddad, Natália Ferreira; Lopes, Luana Siqueira; Cappelletti, Paola Alejandra; de Mello, Wallace; Balduino, Alex

    2016-01-01

    There are promising results in the use of platelet-rich plasma (PRP) for musculoskeletal tissue repair. However, the variability in the methodology for its obtaining may cause different and opposing findings in the literature. Particularly, the choice of the anticoagulant is the first definition to be made. In this work, blood was collected with sodium citrate (SC), ethylenediaminetetraacetic acid (EDTA), or anticoagulant citrate dextrose (ACD) solution A, as anticoagulants, prior to PRP obtaining. Hematological analysis and growth factors release quantification were performed, and the effects on mesenchymal stromal cell (MSC) culture, such as cytotoxicity and cell proliferation (evaluated by MTT method) and gene expression, were evaluated. The use of EDTA resulted in higher platelet yield in whole blood; however, it induced an increase in the mean platelet volume (MPV) following the blood centrifugation steps for PRP obtaining. The use of SC and ACD resulted in higher induction of MSC proliferation. On the other hand, PRP obtained in SC presented the higher platelet recovery after the blood first centrifugation step and a minimal change in MSC gene expression. Therefore, we suggest the use of SC as the anticoagulant for PRP obtaining. PMID:27340410

  2. Optimization of a miniaturized DBD plasma chip for mercury detection in water samples.

    Science.gov (United States)

    Abdul-Majeed, Wameath S; Parada, Jaime H Lozano; Zimmerman, William B

    2011-11-01

    In this work, an optimization study was conducted to investigate the performance of a custom-designed miniaturized dielectric barrier discharge (DBD) microplasma chip to be utilized as a radiation source for mercury determination in water samples. The experimental work was implemented by using experimental design, and the results were assessed by applying statistical techniques. The proposed DBD chip was designed and fabricated in a simple way by using a few microscope glass slides aligned together and held by a Perspex chip holder, which proved useful for miniaturization purposes. Argon gas at 75-180 mL/min was used in the experiments as a discharge gas, while AC power in the range 75-175 W at 38 kHz was supplied to the load from a custom-made power source. A UV-visible spectrometer was used, and the spectroscopic parameters were optimized thoroughly and applied in the later analysis. Plasma characteristics were determined theoretically by analysing the recorded spectroscopic data. The estimated electron temperature (T(e) = 0.849 eV) was found to be higher than the excitation temperature (T(exc) = 0.55 eV) and the rotational temperature (T(rot) = 0.064 eV), which indicates non-thermal plasma is generated in the proposed chip. Mercury cold vapour generation experiments were conducted according to experimental plan by examining four parameters (HCl and SnCl(2) concentrations, argon flow rate, and the applied power) and considering the recorded intensity for the mercury line (253.65 nm) as the objective function. Furthermore, an optimization technique and statistical approaches were applied to investigate the individual and interaction effects of the tested parameters on the system performance. The calculated analytical figures of merit (LOD = 2.8 μg/L and RSD = 3.5%) indicates a reasonable precision system to be adopted as a basis for a miniaturized portable device for mercury detection in water samples.

  3. Influence of sample temperature on the expansion dynamics and the optical emission of laser-induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Eschlböck-Fuchs, S.; Haslinger, M.J.; Hinterreiter, A.; Kolmhofer, P.; Huber, N. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Rössler, R. [voestalpine Stahl GmbH, A-4031 Linz (Austria); Heitz, J. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

    2013-09-01

    We investigate the influence of sample temperature on the dynamics and optical emission of laser induced plasma for various solid materials. Bulk aluminum alloy, silicon wafer, and metallurgical slag samples are heated to temperature T{sub S} ≤ 500 °C and ablated in air by Nd:YAG laser pulses (wavelength 1064 nm, pulse duration approx. 7 ns). The plasma dynamics is investigated by fast time-resolved photography. For laser-induced breakdown spectroscopy (LIBS) the optical emission of plasma is measured by Echelle spectrometers in combination with intensified CCD cameras. For all sample materials the temporal evolution of plume size and broadband plasma emission vary systematically with T{sub S}. The size and brightness of expanding plumes increase at higher T{sub S} while the mean intensity remains independent of temperature. The intensity of emission lines increases with temperature for all samples. Plasma temperature and electron number density do not vary with T{sub S}. We apply the calibration-free LIBS method to determine the concentration of major oxides in slag and find good agreement to reference data up to T{sub S} = 450 °C. The LIBS analysis of multi-component materials at high temperature is of interest for technical applications, e.g. in industrial production processes. - Highlights: • Size and emission of laser-induced plasma increase with sample temperature Ts. • Mean optical intensity of plasma is independent of Ts. • Plasma temperature and electron number density do not vary with Ts. • Major oxides in steel slag are quantified up to Ts = 450 °C. • Industrial steel slags are analyzed by calibration-free LIBS method.

  4. Comparison of geochemical data obtained using four brine sampling methods at the SECARB Phase III Anthropogenic Test CO2 injection site, Citronelle Oil Field, Alabama

    Science.gov (United States)

    Conaway, Christopher; Thordsen, James J.; Manning, Michael A.; Cook, Paul J.; Trautz, Robert C.; Thomas, Burt; Kharaka, Yousif K.

    2016-01-01

    The chemical composition of formation water and associated gases from the lower Cretaceous Paluxy Formation was determined using four different sampling methods at a characterization well in the Citronelle Oil Field, Alabama, as part of the Southeast Regional Carbon Sequestration Partnership (SECARB) Phase III Anthropogenic Test, which is an integrated carbon capture and storage project. In this study, formation water and gas samples were obtained from well D-9-8 #2 at Citronelle using gas lift, electric submersible pump, U-tube, and a downhole vacuum sampler (VS) and subjected to both field and laboratory analyses. Field chemical analyses included electrical conductivity, dissolved sulfide concentration, alkalinity, and pH; laboratory analyses included major, minor and trace elements, dissolved carbon, volatile fatty acids, free and dissolved gas species. The formation water obtained from this well is a Na–Ca–Cl-type brine with a salinity of about 200,000 mg/L total dissolved solids. Differences were evident between sampling methodologies, particularly in pH, Fe and alkalinity. There was little gas in samples, and gas composition results were strongly influenced by sampling methods. The results of the comparison demonstrate the difficulty and importance of preserving volatile analytes in samples, with the VS and U-tube system performing most favorably in this aspect.

  5. Sample selection algorithm to improve quality of genotyping from plasma-derived DNA: to separate the wheat from the chaff.

    Science.gov (United States)

    Schoenborn, Veit; Gohlke, Henning; Heid, Iris M; Illig, Thomas; Utermann, Gerd; Kronenberg, Florian

    2007-11-01

    Plasma and serum samples were often the only biological material collected for earlier epidemiological studies. These studies have a huge informative content, especially due to their long follow-up and would be an invaluable treasure for genetic investigations. However, often no banked DNA is available. To use the small amounts of DNA present in plasma, in a first step, we applied magnetic bead technology to extract this DNA, followed by a whole-genome amplification (WGA) using phi29-polymerase. We assembled 88 sample pairs, each consisting of WGA plasma DNA and the corresponding whole-blood DNA. We genotyped nine highly polymorphic short tandem repeats (STRs) and 23 SNPs in both DNA sources. The average within-pair discordance was 3.8% for SNPs and 15.9% for STR genotypes, respectively. We developed an algorithm based on one-half of the sample pairs and validated on the other one-half to identify the samples with high WGA plasma DNA quality to assure low genotyping error and to exclude plasma DNA samples with insufficient quality: excluding samples showing homozygosity at five or more of the nine STR loci yielded exclusion of 22.7% of all samples and decreased average discordance for STR and SNP markers to 3.92% and 0.63%, respectively. For SNPs, this is very close to the error observed for genomic DNA in many laboratories. Our workflow and sample selection algorithm offers new opportunities to recover reliable DNA from stored plasma material. This algorithm is superior to testing the amount of input DNA.

  6. Pregnancy-associated glycoprotein (PAG) concentration in plasma and milk samples for early pregnancy diagnosis in Lacaune dairy sheep.

    Science.gov (United States)

    El Amiri, B; Sousa, N M; Alvarez Oxiley, A; Hadarbach, D; Beckers, J F

    2015-04-01

    In the present study, four RIA systems (RIA-1 to -4) based on two antisera raised against ovine pregnancy-associated glycoproteins (ovPAGs), combined with an ovine or a bovine PAG tracer were used to measure PAG concentrations in plasma and milk samples of dairy ewes. Blood and milk samples were collected on different days of gestation: 0, 18, 20, 22, 25, 28, 32, 42, and 49. From day 20 onward, the PAG in plasma could be detected in all pregnant ewes using the four RIA systems. By using milk, except for RIA-1, the other systems showed a sensitivity of 100% from day 28 of gestation onward. In plasma, PAG concentrations were higher in multiple than in single pregnancies, while no clear relationship was observed in milk. In conclusion, milk is a good alternative to plasma for early pregnancy diagnosis in sheep from day 28 to day 42.

  7. An evaluation of multiplex bead-based analysis of cytokines and soluble proteins in archived lithium heparin plasma, EDTA plasma and serum samples

    DEFF Research Database (Denmark)

    Brøndum, Line; Sørensen, Brita Singers; Eriksen, Jesper Grau

    2016-01-01

    in plasma and serum from 86 head and neck cancer patients and 33 controls were evaluated: EGFR, leptin, OPN, VEGFR-1, VEGFR-2, IL-2, IL-13, PDGF-bb, TNF, PAI-1, SDF-1a, IL-4, IL-6, IL-8, eotaxin, G-CSF, VEGF, GRO-a, and HGF. RESULTS: The correlation between measurements of the same samples analyzed...

  8. A new method to obtain narrowband emission from a broadband current using increased impedance of plasma-like media (Conference Presentation)

    Science.gov (United States)

    Hur, Min Sup; Ersfeld, Bernhard; Noble, Adam; Suk, Hyyong; Jaroszynski, Dino A.

    2017-05-01

    In conventional radiation sources, narrowband radiation emission can be obtained by narrowband current oscillation. Usually the spectrum of the oscillating current is made narrow by a large or complicated structure for wave-particle interaction. One good example is the beam-undulator system. In this presentation, we introduce a new method to obtain a radiation emission with a well-collimated frequency without changing the broadband nature of a given current source. The method is based on our recent discovery of the new physical properties of the cut-off phenomenon, which broadly exists in general plasma-like media, such as plasma, waveguide, or photonic crystal, etc. A common feature of these media is the Bohm-Gross dispersion relation, which has a frequency condition to make the wavenumber zero. In the zero-wavenumber state, an electromagnetic wave cannot propagate through the medium, but instead, is reflected (i.e. cut-off). In regular steady-state analysis, the cut-off condition is characterized by infinite radiation impedance. An interesting question here is what would happen to the radiation power, if a non-zero current oscillating with the cut-off frequency were enforced in a medium (a current source, in contrast with the regular voltage source). A regular steady-state analysis for this situation leads to infinite power of radiation from Ohm's law. We could solve such a paradoxical situation by analyzing the non-steady-state system; we found that the system can be described by a time-dependent Schroedinger equation with an external driving term. The solution of this equation shows a temporally growing electromagnetic field. When this concept is extended to a generally broadband current source, the spectral density at the cut-off frequency can be selectively enhanced (selectively enhanced emission, SEE). Hence a general broadband radiation source can be easily converted to a narrowband source by enclosing the system with a plasma-like medium. The current

  9. Impact of In doping on GeTe phase-change materials thin films obtained by means of an innovative plasma enhanced metalorganic chemical vapor deposition process

    Science.gov (United States)

    Szkutnik, P. D.; Aoukar, M.; Todorova, V.; Angélidès, L.; Pelissier, B.; Jourde, D.; Michallon, P.; Vallée, C.; Noé, P.

    2017-03-01

    We investigated the deposition and the phase-change properties of In-doped GeTe thin films obtained by plasma enhanced metalorganic chemical vapor deposition and doped with indium using a solid delivery system. The sublimated indium precursor flow rate was calculated as a function of sublimation and deposition parameters. Indium related optical emission recorded by means of optical emission spectroscopy during deposition plasma allowed proposing the dissociation mechanisms of the [In(CH3)2N(CH3)2]2 solid precursor. In particular, using an Ar + H2 + NH3 deposition plasma, sublimated indium molecules are completely dissociated and do not induce by-product contamination by addition of nitrogen or carbon in the films. X-ray photoelectron spectroscopy evidences the formation of In-Te bonds in amorphous as-deposited In-doped GeTe films. The formation of an InTe phase after 400 °C annealing is also evidenced by means of X-ray diffraction analysis. The crystallization temperature Tx, deduced from monitoring of optical reflectivity of In-doped GeTe films with doping up to 11 at. % slightly varies as a function of the In dopant level with a decrease of Tx down to a minimum value for an In doping level of about 6-8 at. %. In this In doping range, the structure of crystallized In-GeTe films changes and is dominated by the presence of a crystalline In2Te3 phase. Finally, the Kissinger activation energy for crystallization Ea is showing to monotonically decrease as the indium content in the GeTe film is increased indicating a promising effect of In doping on crystallization speed in memory devices while keeping a good thermal stability for data retention.

  10. A lipemia-independent NanoDrop(®)-based score to identify hemolysis in plasma and serum samples.

    Science.gov (United States)

    Appierto, Valentina; Callari, Maurizio; Cavadini, Elena; Morelli, Daniele; Daidone, Maria Grazia; Tiberio, Paola

    2014-05-01

    The identification and management of hemolyzed samples are crucial issues in the development of new blood-based biomarkers. Using experiments of controlled hemolysis and lipemia and two plasma series from cancer patients, we developed and validated a lipemia-independent hemolysis score (HS). HS resulted strictly associated with the amount of lysed erythrocytes and with serum index measurement (reference method), highly reproducible, and able to identify as hemolyzed plasma/serum samples containing ≥6.1 mg/dl of free hemoglobin. We developed a simple, robust, sensitive, cost-effective, spectrophotometrically-based system to identify hemolyzed plasma/serum specimens. The procedure requires only 2 μl of sample, thus representing a useful tool for research studies and an essential pre-analytical quality control for an optimal biobanking of liquid biopsies.

  11. Unique C2V3 sequence in HIV-1 envelope obtained from broadly neutralizing plasma of a slow progressing patient conferred enhanced virus neutralization.

    Directory of Open Access Journals (Sweden)

    Rajesh Ringe

    Full Text Available Broadly neutralizing antibodies to HIV-1 usually develops in chronic infections. Here, we examined the basis of enhanced sensitivity of an env clone amplified from cross neutralizing plasma of an antiretroviral naïve chronically infected Indian patient (ID50 >600-fold higher compared to other autologous env clones. The enhanced autologous neutralization of pseudotyped viruses expressing the sensitive envelope (Env was associated with increased sensitivity to reagents and monoclonal antibodies targeting distinct sites in Env. Chimeric viruses constructed by swapping fragments of sensitive Env into resistant Env backbone revealed that the presence of unique residues within C2V3 region of gp120 governed increased neutralization. The enhanced virus neutralization was also associated with low CD4 dependence as well as increased binding of Env trimers to IgG1b12 and CD4-IgG2 and was independent of gp120 shedding. Our data highlighted vulnerabilities in the Env obtained from cross neutralizing plasma associated with the exposure of discontinuous neutralizing epitopes and enhanced autologous neutralization. Such information may aid in Env-based vaccine immunogen design.

  12. Chemical and isotopic characteristics of gas hydrate- and pore-water samples obtained from gas hydrate-bearing sediment cores retrieved from a mud volcano in the Kukuy Canyon, Lake Baikal

    Energy Technology Data Exchange (ETDEWEB)

    Minami, H.; Hachikubo, A.; Krylov, A.; Sakagami, H.; Ohashi, M.; Bai, J.; Kataoka, S.; Yamashita, S.; Takahashi, N.; Shoji, H. [Kitami Inst. of Technology, Kitami (Japan); Khlystov, O.; Zemskaya, T.; Grachev, M. [Russian Academy of Sciences, Irkutsk (Russian Federation). Limnological Inst.

    2008-07-01

    This paper provided details of a method developed to obtain gas hydrate water samples from a mud volcano in Lake Baikal, Russia. Chemical and isotopic analyses were conducted to examine the hydrate and pore water samples as well as to evaluate the original water involved in shallow gas hydrate accumulations in the region. Lake sediment core samples were retrieved from the bottom of the lake with gravity corers. A squeezer was used to take pore water samples from the sediments. Hydrate samples were taken from a gas hydrate placed on a polyethylene funnel. Dissolved hydrate water was filtered through a membrane into bottles. Both samples were kept under chilled or liquid nitrogen temperatures. Ion chromatography was used to determine concentrations of anions and hydrogen carbonate ions. Sodium and magnesium concentrations were determined using an inductively coupled plasma atomic emission spectrometer. An absorption spectrometer was used to determine potassium and calcium concentrations, and a mass spectrometer was used to analyze stable isotopes of oxygen and hydrogen. Results of the study suggested that the gas dissolved in pore water and adsorbed on the surfaces of sediment particles was not the original gas from the hydrates retrieved at the mud volcano. Original gas hydrate-forming fluids were chemically different from the pore- and lake-water samples. The oxygen isotopic composition of the gas hydrate water samples correlated well with hydrogen values. It was concluded that ascending fluid and water delivered the gas into the gas stability zone, and is the main gas hydrate-forming fluid in the area of study. 12 refs., 1 fig.

  13. LacaScore: a novel plasma sample quality control tool based on ascorbic acid and lactic acid levels.

    Science.gov (United States)

    Trezzi, Jean-Pierre; Bulla, Alexandre; Bellora, Camille; Rose, Michael; Lescuyer, Pierre; Kiehntopf, Michael; Hiller, Karsten; Betsou, Fay

    Metabolome analysis is complicated by the continuous dynamic changes of metabolites in vivo and ex vivo. One of the main challenges in metabolomics is the robustness and reproducibility of results, partially driven by pre-analytical variations. The objective of this study was to analyse the impact of pre-centrifugation time and temperature, and to determine a quality control marker in plasma samples. Plasma metabolites were measured by gas chromatography-mass spectrometry (GC-MS) and analysed with the MetaboliteDetector software. The metabolites, which were the most labile to pre-analytical variations, were further measured by enzymatic assays. A score was calculated for their use as quality control markers. The pre-centrifugation temperature was shown to be critical in the stability of plasma samples and had a significant impact on metabolite concentration profiles. In contrast, pre-centrifugation delay had only a minor impact. Based on the results of this study, whole blood should be kept on wet ice and centrifuged within maximum 3 h as a prerequisite for preparing EDTA plasma samples fit for the purpose of metabolome analysis. We have established a novel blood sample quality control marker, the LacaScore, based on the ascorbic acid to lactic acid ratio in plasma, which can be used as an indicator of the blood pre-centrifugation conditions, and hence the suitability of the sample for metabolome analyses. This method can be applied in research institutes and biobanks, enabling assessment of the quality of their plasma sample collections.

  14. Speciation of cisplatin in environmental water samples by hydrophilic interaction liquid chromatography coupled to inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Vidmar, Janja; Martinčič, Anže; Milačič, Radmila; Ščančar, Janez

    2015-06-01

    Cisplatin is still widely used for treatment of numerous types of tumours. Different speciation methods have been applied to study behaviour of the intact drug and its individual biotransformation species in various clinical samples. These methods are mainly based on electrophoresis, size exclusion (SEC) or ion chromatography (IC) techniques coupled to inductively coupled plasma mass spectrometry (ICP-MS). Hydrophilic interaction liquid chromatography (HILIC), which is a common technique for separation of polar substances, was rarely applied for separation of cisplatin and its hydrolysed metabolites. There is also a lack of information available on the occurrence of cisplatin and its hydrolysed complexes in the environmental waters. In the present study the concentrations of Pt were determined in hospital wastewaters by ICP-MS. A procedure for separation of cisplatin and its aqueous hydrolysed complexes by the use of HILIC column was optimized. Quantification of separated Pt species was performed by isotope dilution (ID)-ICP-MS procedure. Low limits of detection (LODs) and quantification (LOQs) were obtained for cisplatin and its hydrolysed complexes ranging from 0.0273 to 0.1726 ng Pt/mL and from 0.0909 to 0.5753 ng Pt/mL, respectively. Good repeatability of the procedure with relative standard deviation (RSD) lower than ±2.3% was obtained. The column recoveries, which ranged from 95 to 101%, indicated that the procedure developed enabled quantitative speciation analysis of aqueous cisplatin complexes. The ZIC-HILIC-ID-ICP-MS procedure was successfully applied in speciation of cisplatin in spiked hospital wastewater samples.

  15. Solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the direct determination of Hg in different materials using isotope dilution with a gaseous phase for calibration

    Science.gov (United States)

    Resano, M.; Gelaude, I.; Dams, R.; Vanhaecke, F.

    2005-03-01

    This paper evaluates the potential of electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICPMS) for the direct determination of Hg in solid samples, using a 200Hg-enriched gaseous phase for calibration based on isotope dilution. Three different samples were studied, BCR CRM 320 River sediment, IAEA-086 Hair and a real (wet) freshwater fish sample (M1). The samples selected show important differences in their matrix composition, and especially the fish sample constitutes a challenge as a result of its high water content (≈80%). The main conclusion of the work is that the calibration approach investigated succesfully corrects for all the matrix effects (suppression) observed during Hg vaporization, allowing accurate values to be obtained in all cases. Moreover, practically the same operating conditions could be used for all sample types. The method finally proposed presents interesting features for the direct determination of this challenging element in solid samples, such as: a low sample consumption (a few milligrams), a high sample throughput (10 min/sample), a low limit of detection (6 ng g -1) and a reduced risk of analyte losses or contamination. Precision values depend on the homogeneity of the sample studied, and are typically in the vicinity of 10% RSD, except for the more inhomogenous river sediment (18% RSD).

  16. Effects of boron addition on a-Si90Ge10:H films obtained by low frequency plasma enhanced chemical vapour deposition

    Science.gov (United States)

    Pérez, Arllene M.; Renero, Francisco J.; Zúñiga, Carlos; Torres, Alfonso; Santiago, César

    2005-06-01

    Optical, structural and electric properties of (a-(Si90Ge10)1-yBy:H) thin film alloys, deposited by low frequency plasma enhanced chemical vapour deposition, are presented. The chemical bonding structure has been studied by IR spectroscopy, while the composition was investigated by Raman spectroscopy. A discussion about boron doping effects, in the composition and bonding of samples, is presented. Transport of carriers has been studied by measurement of the conductivity dependence on temperature, which increases from 10-3 to 101 Ω-1 cm-1 when the boron content varies from 0 to 50%. Similarly, the activation energy is between 0.62 and 0.19 eV when the doping increases from 0 to 83%. The optical properties have been determined from the film's optical transmission, using Swanepoel's method. It is shown that the optical gap varies from 1.3 to 0.99 eV.

  17. Comparison of ESR1 Mutations in Tumor Tissue and Matched Plasma Samples from Metastatic Breast Cancer Patients

    Directory of Open Access Journals (Sweden)

    Takashi Takeshita

    2017-10-01

    Full Text Available BACKGROUND: ESR1 mutation in circulating cell-free DNA (cfDNA is emerging as a noninvasive biomarker of acquired resistance to endocrine therapy, but there is a paucity of data comparing the status of ESR1 gene in cfDNA with that in its corresponding tumor tissue. The objective of this study is to validate the degree of concordance of ESR1 mutations between plasma and tumor tissue. METHODS: ESR1 ligand-binding domain mutations Y537S, Y537N, Y537C, and D538G were analyzed using droplet digital PCR in 35 patients with metastatic breast cancer (MBC (35 tumor tissue samples and 67 plasma samples. RESULTS: Of the 35 paired samples, 26 (74.3% were concordant: one patient had detectable ESR1 mutations both plasma (ESR1 Y537S/Y537N and tumor tissue (ESR1 Y537S/Y537C, and 25 had WT ESR1 alleles in both. Nine (25.7% had discordance between the plasma and tissue results: five had mutations detected only in their tumor tissue (two Y537S, one Y537C, one D538G, and one Y537S/Y537N/D538G, and four had mutations detected only in their plasma (one Y537S, one Y537N, and two Y537S/Y537N/D538G. Furthermore, longitudinal plasma samples from 19 patients were used to assess changes in the presence of ESR1 mutations during treatment. Eleven patients had cfDNA ESR1 mutations over the course of treatment. A total of eight of 11 patients with MBC with cfDNA ESR1 mutations (72.7% had the polyclonal mutations. CONCLUSION: We have shown the independent distribution of ESR1 mutations between plasma and tumor tissue in 35 patients with MBC.

  18. Comparison of a new blood sampling device with the vacuum tube system for plasma and hematological analyses in healthy dogs.

    Science.gov (United States)

    Reynolds, Brice S; Boudet, Karine G; Faucher, Mathieu R; Geffre, Anne; Germain, Claude; Lefebvre, Hervé P

    2008-01-01

    Pediatric devices based on a capillary system may provide an alternative to vacuum tubes for canine blood sampling. The potential advantages are absence of vein collapse, limited blood volume sampled, and improved safety. The aim of this study was to compare routine plasma and hematological variables in seven healthy dogs using both techniques. Five biochemical analytes were measured, and a complete hematological examination and plasma exogenous creatinine clearance test were performed. No clinically relevant difference between the two techniques was observed for any variable or functional test assessed.

  19. Isotope labeled internal standards (ILIS) as a basis for quality control in clinical studies using plasma samples.

    Science.gov (United States)

    Rezeli, Melinda; Végvári, Akos; Marko-Varga, György; Laurell, Thomas

    2010-04-18

    For clinical proteomic studies, the quality of the biofluid samples such as human blood plasma is extremely important. In this study we have investigated the stability of human plasma samples by spiking stable isotope-labeled peptides into the plasma and monitoring their degradation under different storage conditions. FPA-1, C4A and C3f were synthesized with isotopically labeled amino acids, and used as reference peptides. The mixture of internal calibrants was spiked into plasma at the starting point of investigation, mimicking the time of collection for future biobanking efforts, and their qualitative and quantitative changes were analyzed over time by using both MALDI-MS (LTQ Orbitrap XL) and nanoLC-ESI-MS (LTQ XL ETD). We have found that all three synthetic peptides were stable in plasma at -20 and -80 degrees C during the examined 2-month period. However, different proteolytic degradation profiles of the peptides were observed at room temperature. We anticipate that the use of these isotope-labeled peptides as internal standards (ILIS) provides a quality control for long-term storage and proteomic plasma analysis.

  20. Diagnostic efficacy of liquid-based cytology for solid pancreatic lesion samples obtained with endoscopic ultrasound-guided fine-needle aspiration: Propensity score-matched analysis.

    Science.gov (United States)

    Hashimoto, Shinichi; Taguchi, Hiroki; Higashi, Michiyo; Hatanaka, Kazuhito; Fujita, Toshihiro; Iwaya, Hiromichi; Nakazawa, Junichi; Arima, Shiho; Iwashita, Yuji; Sasaki, Fumisato; Nasu, Yuichiro; Kanmura, Shuji; Ido, Akio

    2017-07-01

    There is a paucity of data on the diagnostic efficacy of liquid-based cytology (LBC) for pancreatic samples obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Using propensity score matching, we retrospectively analyzed the additional diagnostic value of LBC compared to a conventional Papanicolaou smear (CPS) for samples of solid pancreatic lesions obtained by EUS-FNA. This cohort study included 126 matched patients who underwent initial EUS-FNA for solid pancreatic lesions between January 2009 and August 2014. CPS was used for cytology of EUS-FNA samples obtained until May 2012 (63 patients). Subsequently, LBC was used for cytological analysis (63 patients). Diagnostic yields of CPS and LBC for malignancy were compared. Risk factors for cytological misdiagnosis with LBC were investigated. Overall rate of malignancy was 86% after matching. LBC had higher diagnostic sensitivity and accuracy than CPS (96.6% vs 84.0%, P = 0.03; and 96.8% vs 87.3%, P = 0.05). LBC was significantly more sensitive for diagnosing pancreatic head lesions (96.4% vs 78.1%, P = 0.04). The sensitivity for pancreatic ductal adenocarcinoma (PDAC) with LBC was higher (98.1% vs 83.0%, P = 0.009). Multivariate analysis revealed that malignant tumors other than PDAC (P = 0.004) and lesion size ≤20 mm (P = 0.046) were risk factors for LBC misdiagnosis in all participants. For solid pancreatic lesions, LBC of EUS-FNA samples contributes to the diagnosis of malignancy. Malignant tumors other than PDAC and small tumors are difficult to diagnose using EUS-FNA and LBC. © 2017 Japan Gastroenterological Endoscopy Society.

  1. Slurry micro-sampling technique for use in argon-helium microwave induced plasma optical emission spectrometry.

    Science.gov (United States)

    Ślachciński, Mariusz

    2016-12-01

    The Flow Focusing Pneumatic Nebulizer (FFPN) working at low liquid flow rates was evaluated for the elemental analysis in slurried samples by argon-helium microwave induced plasma optical emission spectrometry (MIP-OES). The obtained results achieved were compared with commercially available V-groove Babington type nebulizer (VBPN). A univariate approach and the simplex optimization procedure were used to achieve optimized conditions and derive analytical figures of merit. Analytical performance of the micro nebulization system was characterized by a determination of the limits of detection (LODs), the precision (RSDs) and the wash-out times for Ba, Ca, Cd, Cu, Fe, Mg, Mn, Pb and Sr. The experimental concentration detection limits for simultaneous determination, calculated as the concentration giving a signal equal to three times of the standard deviation of the blank (LOD, 3σblank criterion, peak height) were 0.9, 0.2, 0.3, 0.2, 0.3, 0.1, 0.2, 0.4, 0.4 and 0.3ngmL(-1) for Ba, Ca, Cd, Cu, Fe, Mg, Mn, Pb and Sr, respectively. The method offers relatively good precision (RSD ranged from 5% to 8%) for micro-slurry sampling analysis. Analyses of the certified reference materials (NRCC DOLT-2, GBW 07302 and SRM 2710) were performed in order to determine the accuracy available with the presented nebulization systems. The measured contents of elements in the reference materials were in satisfactory agreement with the certified values. In addition, these elements were determined in two real samples. Slurry concentration up to 3% m/v (particles technique. An ultrasonic probe was used to homogenize the slurry in the polypropylene bottle just before its introduction into the nebulizer. The nebulizers exhibited no clogging problems. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Accuracy of recommended sampling and assay methods for the determination of plasma-free and urinary fractionated metanephrines in the diagnosis of pheochromocytoma and paraganglioma: a systematic review.

    Science.gov (United States)

    Därr, Roland; Kuhn, Matthias; Bode, Christoph; Bornstein, Stefan R; Pacak, Karel; Lenders, Jacques W M; Eisenhofer, Graeme

    2017-06-01

    To determine the accuracy of biochemical tests for the diagnosis of pheochromocytoma and paraganglioma. A search of the PubMed database was conducted for English-language articles published between October 1958 and December 2016 on the biochemical diagnosis of pheochromocytoma and paraganglioma using immunoassay methods or high-performance liquid chromatography with coulometric/electrochemical or tandem mass spectrometric detection for measurement of fractionated metanephrines in 24-h urine collections or plasma-free metanephrines obtained under seated or supine blood sampling conditions. Application of the Standards for Reporting of Diagnostic Studies Accuracy Group criteria yielded 23 suitable articles. Summary receiver operating characteristic analysis revealed sensitivities/specificities of 94/93% and 91/93% for measurement of plasma-free metanephrines and urinary fractionated metanephrines using high-performance liquid chromatography or immunoassay methods, respectively. Partial areas under the curve were 0.947 vs. 0.911. Irrespective of the analytical method, sensitivity was significantly higher for supine compared with seated sampling, 95 vs. 89% (p sampling compared with 24-h urine, 95 vs. 90% (p sampling, seated sampling, and urine. Test accuracy increased linearly from 90 to 93% for 24-h urine at prevalence rates of 0.0-1.0, decreased linearly from 94 to 89% for seated sampling and was constant at 95% for supine conditions. Current tests for the biochemical diagnosis of pheochromocytoma and paraganglioma show excellent diagnostic accuracy. Supine sampling conditions and measurement of plasma-free metanephrines using high-performance liquid chromatography with coulometric/electrochemical or tandem mass spectrometric detection provides the highest accuracy at all prevalence rates.

  3. Determination of stable cesium and strontium in rice samples by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Srinuttrakul, W.; Yoshida, S.

    2017-06-01

    For long-term radiation dose assessment models, food ingestion is one of the major exposure pathways to human. In general, the stable isotopes can serve as analogues of radioisotopes. In this study, rice samples were collected from 30 paddy fields in Si Sa Ket, Yasothon and Roi Et in the northeast of Thailand in November 2014. The concentrations of stable cesium (Cs-133) and strontium (Sr-88) in polished rice were determined by inductively coupled plasma mass spectrometry (ICP-MS). The standard reference material of rice flour (NIST 1568a) with spiked Cs and Sr was used to validate the analytical method. The concentration of Cs in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.158 ± 0.167 mg kg-1, 0.090 ± 0.117 mg kg-1 and 0.054 ± 0.031 mg kg-1, respectively. The concentration of Sr in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.351 ± 0.108 mg kg-1, 0.364 ± 0.215 mg kg-1 and 0.287 ± 0.102 mg kg-1, respectively. Comparison of the results with Japanese data before the Fukushima Di-ichi nuclear power plant accident showed that the concentrations of both Cs and Sr for Thai rice were higher than those for Japanese rice.

  4. Heat Transfer in the Anode Region in Plasma-Electrolytic Heating of a Cylindrical Sample

    Science.gov (United States)

    Zhirov, A. V.; Belkin, P. N.; Shadrin, S. Yu.

    2017-07-01

    The energy balance in a three-phase system "anode-vapor/gas envelope-electrolyte" and the results of experimental determination of the heat fluxes acting in the vapor-gas envelope are considered. To determine the fluxes quantitatively, the calorimetric method and the theory of inverse problems of the thermal conductivity of solid bodies are used. It is shown that heat fluxes into the anode and electrolyte increase with the voltage delivered to the electrochemical cell, whereas the heat flux associated with the vapor release to the atmosphere remains practically unchanged. An increase in the concentration of the current-conducting component in the electrolyte leads to a certain growth of the heat flux into the anode and to a decrease of the flux into the electrolyte. The stages of a nonstationary period of the process of plasma-electrolytic heating have been revealed, and it has been established that the time of heating the vapor-gas envelope is several times shorter than the time of heating a sample.

  5. Detection of Mycobacterium avium subspecies paratuberculosis specific IS900 insertion sequences in bulk-tank milk samples obtained from different regions throughout Switzerland

    Directory of Open Access Journals (Sweden)

    Stephan Roger

    2002-06-01

    Full Text Available Abstract Background Since Mycobacterium avium subspecies paratuberculosis (MAP was isolated from intestinal tissue of a human patient suffering Crohn's disease, a controversial discussion exists whether MAP have a role in the etiology of Crohn's disease or not. Raw milk may be a potential vehicle for the transmission of MAP to human population. In a previous paper, we have demonstrated that MAP are found in raw milk samples obtained from a defined region in Switzerland. The aim of this work is to collect data about the prevalence of MAP specific IS900 insertion sequence in bulk-tank milk samples in different regions of Switzerland. Furthermore, we examined eventual correlation between the presence of MAP and the somatic cell counts, the total colony counts and the presence of Enterobacteriaceae. Results 273 (19.7% of the 1384 examined bulk-tank milk samples tested IS900 PCR-positive. The prevalence, however, in the different regions of Switzerland shows significant differences and ranged from 1.7% to 49.2%. Furthermore, there were no statistically significant (p >> 0.05 differences between the somatic cell counts and the total colony counts of PCR-positive and PCR-negative milk samples. Enterobacteriaceae occur as often in IS900 PCR-positive as in PCR-negative milk samples. Conclusion This is the first study, which investigates the prevalence of MAP in bulk-tank milk samples all over Switzerland and infers the herd-level prevalence of MAP infection in dairy herds. The prevalence of 19.7% IS900 PCR-positive bulk-milk samples shows a wide distribution of subclinical MAP-infections in dairy stock in Switzerland. MAP can therefore often be transmitted to humans by raw milk consumption.

  6. A Method to Correlate mRNA Expression Datasets Obtained from Fresh Frozen and Formalin-Fixed, Paraffin-Embedded Tissue Samples: A Matter of Thresholds.

    Directory of Open Access Journals (Sweden)

    Dana A M Mustafa

    Full Text Available Gene expression profiling of tumors is a successful tool for the discovery of new cancer biomarkers and potential targets for the development of new therapeutic strategies. Reliable profiling is preferably performed on fresh frozen (FF tissues in which the quality of nucleic acids is better preserved than in formalin-fixed paraffin-embedded (FFPE material. However, since snap-freezing of biopsy materials is often not part of daily routine in pathology laboratories, one may have to rely on archival FFPE material. Procedures to retrieve the RNAs from FFPE materials have been developed and therefore, datasets obtained from FFPE and FF materials need to be made compatible to ensure reliable comparisons are possible.To develop an efficient method to compare gene expression profiles obtained from FFPE and FF samples using the same platform.Twenty-six FFPE-FF sample pairs of the same tumors representing various cancer types, and two FFPE-FF sample pairs of breast cancer cell lines, were included. Total RNA was extracted and gene expression profiling was carried out using Illumina's Whole-Genome cDNA-mediated Annealing, Selection, extension and Ligation (WG-DASL V3 arrays, enabling the simultaneous detection of 24,526 mRNA transcripts. A sample exclusion criterion was created based on the expression of 11 stably expressed reference genes. Pearson correlation at the probe level was calculated for paired FFPE-FF, and three cut-off values were chosen. Spearman correlation coefficients between the matched FFPE and FF samples were calculated for three probe lists with varying levels of significance and compared to the correlation based on all measured probes. Unsupervised hierarchical cluster analysis was performed to verify performance of the included probe lists to compare matched FPPE-FF samples.Twenty-seven FFPE-FF pairs passed the sample exclusion criterion. From the profiles of 27 FFPE and FF matched samples, the best correlating probes were identified

  7. Bacterial spore inactivation by atmospheric-pressure plasmas in the presence or absence of UV photons as obtained with the same gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Boudam, M K [Groupe de Physique des Plasmas, Universite de Montreal, CP 6128, Succursale Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Moisan, M [Groupe de Physique des Plasmas, Universite de Montreal, CP 6128, Succursale Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Saoudi, B [Groupe de Physique des Plasmas, Universite de Montreal, CP 6128, Succursale Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Popovici, C [Groupe de Physique des Plasmas, Universite de Montreal, CP 6128, Succursale Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Gherardi, N [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex (France); Massines, F [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex (France)

    2006-08-21

    This paper comprises two main parts: a review of the literature on atmospheric-pressure discharges used for micro-organism inactivation, focused on the inactivation mechanisms, and a presentation of our research results showing, in particular, that UV photons can be the dominant species in the inactivation process. The possibility of achieving spore inactivation through UV radiation using an atmospheric-pressure discharge or its flowing afterglow is the object of a continuing controversy. In fact, the review of the literature that we present shows that a majority of researchers have come to the conclusion that, at atmospheric pressure, chemically reactive species such as free radicals, metastable atoms and molecules always control the inactivation process, while UV photons play only a minor role or no role at all. In contrast, only a few articles suggest or claim that UV photons coming from atmospheric-pressure discharges can, in some cases, inactivate micro-organisms, but the experimental data presented and the supporting arguments brought forward in that respect are relatively incomplete. Using a dielectric-barrier discharge operated at atmospheric pressure in an N{sub 2}-N{sub 2}O mixture, we present, for the first time, experiments where micro-organisms are subjected to plasma conditions such that, on the one hand, UV radiation is strong or, on the other hand, there is no UV radiation, the two different situations being obtained with the same experimental arrangement, including the same gas mixture, N{sub 2}-N{sub 2}O. To achieve maximum UV radiation, the concentration of the oxidant molecule (N{sub 2}O) added to N{sub 2} needs to be tuned carefully, resulting then in the fastest inactivation rate. The concentration range of the oxidant molecule in the mixture for which the UV intensity is significant is extremely narrow, a fact that possibly explains why such a mode of plasma sterilization was not readily observed. The survival curves obtained under dominant

  8. Energy-Dispersive X-Ray Spectroscopy Mapping of Porous Coatings Obtained on Titanium by Plasma Electrolytic Oxidation in a Solution Containing Concentrated Phosphoric Acid with Copper Nitrate

    Directory of Open Access Journals (Sweden)

    Rokosz K.

    2016-09-01

    Full Text Available The SEM and EDS study results of coatings obtained on titanium by Plasma Electrolytic Oxidation (PEO in the electrolytes containing of 600 g copper nitrate in 1 liter of concentrated phosphoric acid at 450 V for 1 and 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. It was found that the time of PEO oxidation has impact on the chemical composition of the coatings. The longer time of PEO treatment, the higher amount of copper inside coating. The PEO oxidation of titanium for 1 minute has resulted in the creation of coating, on which 3 phases where found, which contained up to 13.4 wt% (9 at% of copper inside the phosphate structure. In case of 1 minute PEO treatment of titanium, the 2 phases were found, which contained up to 13 wt% (8 at% of copper inside the phosphate structure. The copper-to-phosphorus ratios after 1 minute processing belong to the range from 0.28 by wt% (0.14 by at% to 0.47 by wt% (0.23 by at%, while after 3 minutes the same ratios belong to the range from 0.27 by wt% (0.13 by at% to 0.35 by wt% (0.17 by at%. In summary, it should be stated that the higher amounts of phosphorus and copper were recorded on titanium after PEO oxidation for 3 minutes than these after 1 minute.

  9. Sequential cloud point extraction of trace elements from biological samples and determination by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gine, Maria Fernanda; Patreze, Aparecida F.; Silva, Edson L. [Centro de Energia Nuclear na Agricultura (CENA-USP), Piracicaba, SP (Brazil)]. E-mail: mfgine@cena.usp.br; Sarkis, Jorge E.S.; Kakazu, Mauricio H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2008-07-01

    A two-step sequential cloud point extraction (CPE) of trace elements from small sample volumes of human serum, animal blood, and food diet is proposed to gain analytical information in the analysis by inductively coupled plasma mass spectrometry. The first CPE was attained by adding O,O-diethyldithiophosphate, the non ionic surfactant Triton{sup R} X-114 followed by heating at 40 deg C, centrifugation and cooling at 0 deg C. The resulting surfactant-rich phase was separated to determine Cd, Pb and Cu by isotope dilution. Isotope ratio measurements presented RSD < 0.7%. The residual surfactant-poor phase solution had the pH adjusted in the range 4 to 5 before the chelating reagent, 4-(2-pyridylazo) resorcinol plus surfactant Triton{sup R} X-114 were added followed by the sequence to attain the CPE. Co and Ni were quantified in the second extracted surfactant-rich phases by standard additions method with RSD < 2%. Recoveries from 85 to 96% were obtained for all elements. Analyzing reference materials with certified and recommended values assessed accuracy. (author)

  10. Quantitative determination of fentanyl in newborn pig plasma and cerebrospinal fluid samples by HPLC-MS/MS.

    Science.gov (United States)

    Blanco, M E; Encinas, E; González, O; Rico, E; Vozmediano, V; Suárez, E; Alonso, R M

    2015-09-01

    In this study, a selective and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method requiring low sample volume (≤100 μL) was developed and validated for the quantitative determination of the opioid drug fentanyl in plasma and cerebrospinal fluid (CSF). A protein precipitation extraction with acetonitrile was used for plasma samples whereas CSF samples were injected directly on the HPLC column. Fentanyl and (13) C6 -fentanyl (Internal Standard) were analyzed in an electrospray ionization source in positive mode, with multiple reaction monitoring (MRM) of the transitions m/z 337.0/188.0 and m/z 337.0/105.0 for quantification and confirmation of fentanyl, and m/z 343.0/188.0 for (13) C6 -fentanyl. The respective lowest limits of quantification for plasma and CSF were 0.2 and 0.25 ng/mL. Intra- and inter-assay precision and accuracy did not exceed 15%, in accordance with bioanalytical validation guidelines. The described analytical method was proven to be robust and was successfully applied to the determination of fentanyl in plasma and CSF samples from a pharmacokinetic and pharmacodynamic study in newborn piglets receiving intravenous fentanyl (5 µg/kg bolus immediately followed by a 90-min infusion of 3 µg/kg/h).

  11. A Comprehensive Software and Database Management System for Glomerular Filtration Rate Estimation by Radionuclide Plasma Sampling and Serum Creatinine Methods.

    Science.gov (United States)

    Jha, Ashish Kumar

    2015-01-01

    Glomerular filtration rate (GFR) estimation by plasma sampling method is considered as the gold standard. However, this method is not widely used because the complex technique and cumbersome calculations coupled with the lack of availability of user-friendly software. The routinely used Serum Creatinine method (SrCrM) of GFR estimation also requires the use of online calculators which cannot be used without internet access. We have developed user-friendly software "GFR estimation software" which gives the options to estimate GFR by plasma sampling method as well as SrCrM. We have used Microsoft Windows(®) as operating system and Visual Basic 6.0 as the front end and Microsoft Access(®) as database tool to develop this software. We have used Russell's formula for GFR calculation by plasma sampling method. GFR calculations using serum creatinine have been done using MIRD, Cockcroft-Gault method, Schwartz method, and Counahan-Barratt methods. The developed software is performing mathematical calculations correctly and is user-friendly. This software also enables storage and easy retrieval of the raw data, patient's information and calculated GFR for further processing and comparison. This is user-friendly software to calculate the GFR by various plasma sampling method and blood parameter. This software is also a good system for storing the raw and processed data for future analysis.

  12. Evaluation of chemiluminescence method for the analysis of plasma homocysteine and comparison with HPLC method in children samples

    OpenAIRE

    Thais Moura Gascón; Fernanda Schindler; Claudia Giorgia Bronzatti de Oliveira; Fabiola Isabel Suano Souza; Sonia Hix; Roseli Oselka Sacardo Sarni; Ana Paula Arantes Bacan; Vania D’Almeida; Auro del Giglio; Fernando Luiz Affonso Fonseca

    2010-01-01

    ABSTRACT Objective: To compare the results for homocysteine concentration using chemiluminescence and HPLC methods in samples from school-age children. In addition, to determine the reference values for patients of this age group and assess the real prognostic value of homocysteine in healthy children. Methods: A prospective observational study was undertaken to determine plasma levels of homocysteine using two different assays, HPLC and chemiluminescence, in 185 samples from school-age chi...

  13. Evaluation of Sample Stability and Automated DNA Extraction for Fetal Sex Determination Using Cell-Free Fetal DNA in Maternal Plasma

    Directory of Open Access Journals (Sweden)

    Elena Ordoñez

    2013-01-01

    Full Text Available Objective. The detection of paternally inherited sequences in maternal plasma, such as the SRY gene for fetal sexing or RHD for fetal blood group genotyping, is becoming part of daily routine in diagnostic laboratories. Due to the low percentage of fetal DNA, it is crucial to ensure sample stability and the efficiency of DNA extraction. We evaluated blood stability at 4°C for at least 24 hours and automated DNA extraction, for fetal sex determination in maternal plasma. Methods. A total of 158 blood samples were collected, using EDTA-K tubes, from women in their 1st trimester of pregnancy. Samples were kept at 4°C for at least 24 hours before processing. An automated DNA extraction was evaluated, and its efficiency was compared with a standard manual procedure. The SRY marker was used to quantify cfDNA by real-time PCR. Results. Although lower cfDNA amounts were obtained by automated DNA extraction (mean 107,35 GE/mL versus 259,43 GE/mL, the SRY sequence was successfully detected in all 108 samples from pregnancies with male fetuses. Conclusion. We successfully evaluated the suitability of standard blood tubes for the collection of maternal blood and assessed samples to be suitable for analysis at least 24 hours later. This would allow shipping to a central reference laboratory almost from anywhere in Europe.

  14. Determination of trace elements in water samples by ultrasonic nebulization inductively coupled plasma mass spectrometry after cloud point extraction

    Science.gov (United States)

    Mesquita da Silva, Márcia Andreia; Azzolin Frescura, Vera Lúcia; Curtius, Adilson José

    2000-07-01

    A preconcentration method for low concentrations of Ag, As, Au, Cd, Cu, Pb and Se in water, using cloud point extraction is proposed. The analytes in the initial aqueous solution, acidified with hydrochloric acid, are complexed with ammonium O, O-diethyl-dithiophosphate, and 0.05% m/v Triton X-114 is added as surfactant. The complexation allows the separation of the analytes from alkali, alkaline earth and other elements, which are not complexed. After phase separation, by increasing the temperature above 20°C, depending on the cloud point of the mixture, and dilution of the surfactant-rich phase with a mixture of 60% v/v methanol and 40% v/v of 1% v/v aqueous nitric acid solution, the enriched analytes are determined by inductively coupled plasma mass spectrometry, using ultrasonic nebulization, injecting 100 μl of the enriched phase with a flow injection (FI) system. Since the initial volume is 40 ml and the final volume is 1 ml, good enrichment factors are obtained. After optimization of the complexation (pH and DDTP concentration), of extraction conditions, sample introduction (FI and ultrasonic nebulizer parameters) and spectrometer conditions, the method was applied to the analysis of riverine water, sea water and enriched water reference materials, and good agreement with the certified values was obtained. By introducing the organic extract with the FI system and using ultrasonic nebulization, no carbon deposits on the interface cones and lens were observed, allowing extensive use of the spectrometer without cleaning and re-optimization.

  15. Optimization of the operating conditions of solid sampling electrothermal vaporization coupled to inductively coupled plasma optical emission spectrometry for the sensitive direct analysis of powdered rice.

    Science.gov (United States)

    Sadiq, Nausheen; Beauchemin, Diane

    2014-12-03

    Two different approaches were used to improve the capabilities of solid sampling (SS) electrothermal vaporization (ETV) coupled to inductively coupled plasma optical emission spectrometry (ICP-OES) for the direct analysis of powdered rice. Firstly, a cooling step immediately before and after the vaporization step in the ETV temperature program resulted in a much sharper analyte signal peak. Secondly, point-by-point internal standardization with an Ar emission line significantly improved the linearity of calibration curves obtained with an increasing amount of rice flour certified reference material (CRM). Under the optimized conditions, detection limits ranged from 0.01 to 6ngg(-1) in the solid, depending on the element and wavelength selected. The method was validated through the quantitative analysis of corn bran and wheat flour CRMs. Application of the method to the multi-elemental analysis of 4-mg aliquots of real organic long grain rice (white and brown) also gave results for Al, As, Co, Cu, Fe, Mg, Se, Pb and Zn in agreement with those obtained by inductively coupled plasma mass spectrometry following acid digestion of 0.2-g aliquots. As the analysis takes roughly 5min per sample (2.5min for grinding, 0.5-1min for weighing a 4-mg aliquot and 87s for the ETV program), this approach shows great promise for fast screening of food samples.

  16. Potential of Solid Sampling Electrothermal Vaporization for solving spectral interference in Inductively Coupled Plasma Optical Emission Spectrometry

    Science.gov (United States)

    Asfaw, Alemayehu; Wibetoe, Grethe

    2009-05-01

    Spectral interference is one of the main causes of erroneous results in Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). This paper describes some cases of spectral interferences with conventional nebulization ICP-OES and the potential of solving them utilizing electrothermal vaporization for volatility-based separation. The cases studied were, the well-known spectral overlap between the As and Cd lines at 228.8 nm that are only 10 pm apart, and the interference of Fe on the main emission lines of As, Cd and Pb. The spectral interferences were studied by monitoring the typical signals of solutions that contain the analytes and the potential interferent, by studying the spectra and calculating Background Equivalent Concentration (BEC)-values. A three step temperature program was developed to be used for direct analysis of solid soil samples by Electrothermal Vaporization (ETV)-ICP-OES: step 1 (760 °C, 40 s), step 2 (1620 °C, 20 s) and a cleaning step (2250 °C, 10 s) where Cd vaporizes in step 1, As, Pb and part of Fe in step 2 and the major part of Fe in the cleaning step. Because As and Cd were time-separated using this program, their prominent lines at 228.8 nm, could be used for determination of each element by ETV-ICP-OES, in spite of the serious wavelength overlap. Selective vaporization was also shown to reduce or eliminate the Fe background emission on As, Cd and Pb lines. To confirm the applicability of the method, a solid soil certified reference materials was analyzed directly without any sample treatment. Good or reasonable accuracy was obtained for the three elements.

  17. Automated Sample Preparation Platform for Mass Spectrometry-Based Plasma Proteomics and Biomarker Discovery

    Directory of Open Access Journals (Sweden)

    Vilém Guryča

    2014-03-01

    Full Text Available The identification of novel biomarkers from human plasma remains a critical need in order to develop and monitor drug therapies for nearly all disease areas. The discovery of novel plasma biomarkers is, however, significantly hampered by the complexity and dynamic range of proteins within plasma, as well as the inherent variability in composition from patient to patient. In addition, it is widely accepted that most soluble plasma biomarkers for diseases such as cancer will be represented by tissue leakage products, circulating in plasma at low levels. It is therefore necessary to find approaches with the prerequisite level of sensitivity in such a complex biological matrix. Strategies for fractionating the plasma proteome have been suggested, but improvements in sensitivity are often negated by the resultant process variability. Here we describe an approach using multidimensional chromatography and on-line protein derivatization, which allows for higher sensitivity, whilst minimizing the process variability. In order to evaluate this automated process fully, we demonstrate three levels of processing and compare sensitivity, throughput and reproducibility. We demonstrate that high sensitivity analysis of the human plasma proteome is possible down to the low ng/mL or even high pg/mL level with a high degree of technical reproducibility.

  18. Extraction of HCV-RNA from Plasma Samples: Development towards Semiautomation

    Directory of Open Access Journals (Sweden)

    Imran Amin

    2015-01-01

    Full Text Available A semiautomated extraction protocol of HCV-RNA using Favorgen RNA extraction kit has been developed. The kit provided protocol was modified by replacing manual spin steps with vacuum filtration. The assay performance was evaluated by real-time qPCR based on Taqman technology. Assay linearity was confirmed with the serial dilutions of RTA (Turkey containing 1 × (106, 105, 104, and 103 IU mL−1. Comparison of test results obtained by two extraction methods showed a good correlation (r=0.95, n=30 with detection limit of 102 IU mL−1. The semiautomated vacuum filtration based protocol demonstrated high throughput: 35 minutes for the extraction of a batch of 30 samples (150 µL each with reduced labor, time, waste, and cost. Performance characteristics of semiautomated system make it suitable for use in diagnostic purpose and viral load determinations.

  19. Analytical performances of laser-induced micro-plasma of Al samples with single and double ultrashort pulses in air and with Ar-jet: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Semerok, A., E-mail: alexandre.semerok@cea.fr [CEA Saclay, DEN/DPC/SEARS/LISL, 91191 Gif-sur-Yvette (France); Dutouquet, C. [CEA Saclay, DEN/DPC/SEARS/LISL, 91191 Gif-sur-Yvette (France); INERIS/DRC/CARA/NOVA, F-60550 Verneuil En Halatte (France)

    2014-09-01

    Ultrashort pulse laser microablation coupled with optical emission spectroscopy was under study to obtain several micro-LIBS analytical features (shot-to-shot reproducibility, spectral line intensity and lifetime, calibration curves, detection limits). Laser microablation of Al matrix samples with known Cu- and Mg-concentrations was performed by single and double pulses of 50 fs and 1 ps pulse duration in air and with Ar-jet. The micro-LIBS analytical features obtained under different experimental conditions were characterized and compared. The highest shot-to-shot reproducibility and gain in plasma spectral line intensity were obtained with double pulses with Ar-jet for both 50 fs and 1 ps pulse durations. The best calibration curves were obtained with 1 ps pulse duration with Ar-jet. Micro-LIBS with ultrashort double pulses may find its effective application for surface elemental microcartography. - Highlights: • Analytical performances of micro-LIBS with ultrashort double pulses were studied. • The maximal line intensity gain of 20 was obtained with double pulses and Ar-jet. • LIBS gain was obtained without additional ablation of a sample by the second pulse. • LIBS properties were almost the same for both 50 fs and 1 ps pulses. • The micro-LIBS detection limit was around 35 ppm.

  20. Study of plasma amino acid levels in children with autism: An Egyptian sample

    Directory of Open Access Journals (Sweden)

    Farida M. ElBaz

    2014-04-01

    Conclusions: Autistic children had lower levels of some plasma amino acids except for glycine and glutamic acids and phosphoserine were increased with normal serum levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma.

  1. Direct fermentation of gelatinized cassava starch to acetone, butanol, and ethanol using Clostridium acetobutylicum mutant obtained by atmospheric and room temperature plasma.

    Science.gov (United States)

    Li, Han-guang; Luo, Wei; Wang, Qiang; Yu, Xiao-bin

    2014-04-01

    The mutant strain designated as ART18, obtained from the wild-type strain Clostridium acetobutylicum PW12 treated by atmospheric and room temperature plasma, showed higher solvent tolerance and butanol production than that of the wild-type strain. The production of butanol was 11.3 ± 0.5 g/L, 31 % higher than that of the wild-type strain when it was used for acetone, butanol, and ethanol fermentation in P2 medium. Furthermore, the effects of cassava flour concentration, pH regulators, and vitamins on the ABE production were also investigated. The highest butanol production of 15.8 ± 0.8 g/L and butanol yield (0.31 g/g) were achieved after the above factors were optimized. When acetone, butanol, and ethanol fermentation by ART18 was carried out in a 15-L bioreactor, the butanol production, the productivity of butanol, and the total solvent were 16.3 ± 0.9, 0.19, and 0.28 g/L(/)h, respectively. These results indicate that ART18 is a promising industrial producer in ABE fermentation.

  2. Relevance of the choice of spark plasma sintering parameters in obtaining a suitable microstructure for iodine-bearing apatite designed for the conditioning of I-129

    Energy Technology Data Exchange (ETDEWEB)

    Campayo, L., E-mail: lionel.campayo@cea.fr [CEA, DEN, DTCD/SECM/LDMC – Marcoule, F-30207 Bagnols-sur-Cèze (France); Le Gallet, S. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-UB, 9 Av. Alain Savary, BP 47870, 21078 Dijon Cedex (France); Perret, D.; Courtois, E. [CEA, DEN, DTCD/SECM/LDMC – Marcoule, F-30207 Bagnols-sur-Cèze (France); Cau Dit Coumes, C. [CEA, DEN, DTCD/SPDE/LP2C – Marcoule, F-30207 Bagnols-sur-Cèze (France); Grin, Yu. [Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden (Germany); Bernard, F. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-UB, 9 Av. Alain Savary, BP 47870, 21078 Dijon Cedex (France)

    2015-02-15

    Highlights: • Modeling of reactive sintering by SPS of an iodoapatite for waste immobilization. • Use of a statistical approach to surmount the complexity of the process. • The supposed most resistant microstructure towards leaching is obtained at 450 °C. • Pressure has no influence in the liquid sintering regime. - Abstract: The high chemical durability of iodine-bearing apatite phases makes them potentially attractive for immobilizing radioactive iodine. Reactive spark plasma sintering provides a dense ceramic as a wasteform. A design-of-experiments (DOE) approach was adopted to identify the main process/material parameters and their first order interactions in order to specify experimental conditions guaranteeing complete reaction, relative density of the wasteform exceeding 92% and the largest possible grain size. For a disposal of the wasteform in a deep geological repository, these characteristics allow minimization of the iodine release by contact with groundwater. It was found that sintering at a temperature of 450 °C with an initial specific surface area of 3.3 m{sup 2} g{sup −1} for the powder reactants is sufficient in itself to achieve the targeted characteristics of the wasteform. However, this relies on a liquid sintering regime the efficiency of which can be limited by the lead iodide initial content in the mix as well as by its particle size.

  3. Effects of boron addition on a-Si{sub 90}Ge{sub 10}:H films obtained by low frequency plasma enhanced chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Arllene M [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Luis E Erro no. 1, Santa Maria Tonantzintla, CP 72840, Puebla, Puebla (Mexico); Universidad Popular Autonoma del Estado de Puebla (UPAEP), 21 Sur 1103 Colonia Santiago, CP 72160, Puebla, Puebla (Mexico); Renero, Francisco J [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Luis E Erro no. 1, Santa Maria Tonantzintla, CP 72840, Puebla, Puebla (Mexico); Zuniga, Carlos [Instituto Nacional de AstrofIsica, Optica y Electronica (INAOE), Luis E Erro no. 1, Santa MarIa Tonantzintla, CP 72840, Puebla, Puebla (Mexico); Torres, Alfonso [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Luis E Erro no. 1, Santa MarIa Tonantzintla, CP 72840, Puebla, Puebla (Mexico); Santiago, Cesar [Universidad Politecnica de Tulancingo, Prolongacion Guerrero 808 Colonia Caltengo, CP 43626, Tulancingo, Hidalgo (Mexico)

    2005-06-29

    Optical, structural and electric properties of (a-(Si{sub 90}Ge{sub 10}){sub 1-y}B{sub y}:H) thin film alloys, deposited by low frequency plasma enhanced chemical vapour deposition, are presented. The chemical bonding structure has been studied by IR spectroscopy, while the composition was investigated by Raman spectroscopy. A discussion about boron doping effects, in the composition and bonding of samples, is presented. Transport of carriers has been studied by measurement of the conductivity dependence on temperature, which increases from 10{sup -3} to 10{sup 1} {omega}{sup -1} cm{sup -1} when the boron content varies from 0 to 50%. Similarly, the activation energy is between 0.62 and 0.19 eV when the doping increases from 0 to 83%. The optical properties have been determined from the film's optical transmission, using Swanepoel's method. It is shown that the optical gap varies from 1.3 to 0.99 eV.

  4. Papanicolaou test in the detection of high-grade cervical lesions: a re-evaluation based on cytohistologic non-correlation rates in 356 concurrently obtained samples.

    Science.gov (United States)

    Carns, Bhavini; Fadare, Oluwole

    2008-01-01

    Studies evaluating the routine Papanicolaou (Pap) test have traditionally used as the reference gold standard, the diagnoses on the follow-up histologic samples. Since the latter are typically obtained days to weeks after the Pap test, the accuracy of the resultant comparison may be affected by interim factors, such as regression of human papillomavirus, new lesion acquisitions or colposcopy-associated variability. A subset of our clinicians have routinely obtained cervical cytology samples immediately prior to their colposcopic procedures, which presented a unique opportunity to re-evaluate the test performance of liquid-based cervical cytology in detecting the most clinically significant lesions (i.e. cervical intraepithelial neoplasia 2 or worse: CIN2+), using as gold standard, diagnoses on cervical biopsies that were essentially obtained simultaneously. For each patient, cytohistologic non-correlation between the Pap test and biopsy was considered to be present when either modality displayed a high-grade squamous intraepithelial lesion (HGSIL)/CIN2+ while the other displayed a less severe lesion. Therefore, HGSIL/CIN2+ was present in both the Pap test and biopsy in true positives, and absent in both modalities in true negatives. In false positives, the Pap test showed HGSIL while the biopsy showed less than a CIN2+. In false negatives, Pap tests displaying less than a HGSIL were associated with biopsies displaying CIN2+. Combinations associated with "atypical" interpretations were excluded. A cytohistologic non-correlation was present in 17 (4.8%) of the 356 combinations reviewed. The non-correlation was attributed, by virtue of having the less severe interpretation, to the Pap test in all 17 cases. There were 17, 322, 0, and 17 true positives, true negatives, false positives and false negatives respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the Pap test, at a diagnostic threshold of HGSIL, in identifying

  5. Assessing the uncertainty of biomass change estimates obtained using multi-temporal field, lidar sampling, and satellite imagery on the Kenai Peninsula of Alaska (Invited)

    Science.gov (United States)

    Andersen, H.

    2013-12-01

    There is increasing interest in the development of statistical sampling designs for aboveground biomass (and carbon) inventory and monitoring programs that can make efficient use of a variety of available data sources, including field plots, airborne lidar sampling, and satellite imagery. While the use of multiple sources, or levels, of remote sensing data can significantly increase the precision of biomass change estimates, especially in remote areas (such as interior Alaska) where it is extremely expensive to establish field plots, it can be challenging to accurately characterize the uncertainty (i.e. variance and bias) of the estimates obtained from these complex multi-level designs. In this study we evaluate a model-based approach to estimate changes in biomass over the western lowlands of the Kenai Peninsula of Alaska during the period 2004-2009 using a combination of field plots, lidar sampling, and satellite imagery. The model-based approach -- where all inferences are conditioned on the model relating the remote-sensing measurements to the inventory parameter of interest (e.g. biomass) - is appropriate for cases where it is cost-prohibitive, or infeasible, to establish a probability sample of field plots that are both spatially and temporally coincident with each remote sensing data set. For example, a model-based approach can be used to obtain biomass estimates over a period of time, even when field data is only available for the current time period. In this study, lidar data were collected in 2004 and 2009 over single swaths that covered 130 Forest Inventory and Analysis (FIA) plots distributed on a regular grid over the entire western Kenai. Field measurements on FIA plots were initially acquired over the period 1999-2003 and fifty-percent of these plots were remeasured in the period 2004-2009. In addition, high-accuracy coordinates (GPS equipment. Changes in biomass (and associated uncertainty) estimated from field remeasurements alone were compared to

  6. Calcified Pulmonary Nodules Identified in a 350-Year-Old-Joseon Mummy: the First Report on Ancient Pulmonary Tuberculosis from Archaeologically Obtained Pre-modern Korean Samples

    Science.gov (United States)

    2016-01-01

    We found calcified pulmonary nodules in a middle-aged female mummy discovered from 350-yr-old Joseon tomb of Korea. In the CT scan, we found six radiopaque nodules in right lung, through the levels of thoracic vertebrae 1 to 6. We also found presumptive pleural adhesions in right thoracic cavity of CT images. We re-confirmed radiological findings by our post-factum dissection on the same mummy. By the differential diagnosis, we speculate that the radiopaque calcification nodules and associated pleural adhesion could have been caused by tuberculosis. This is the first-ever report on the pulmonary tuberculosis identified in archaeologically obtained, pre-modern Korean samples. PMID:26770051

  7. Thin films of hydrogenated amorphous carbon (a-C:H) obtained through chemical vapor deposition assisted by plasma; Peliculas delgadas de carbono amorfo hidrogenado (a-C:H) obtenidas mediante deposito quimico de vapores asistido por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Mejia H, J.A.; Camps C, E.E.; Escobar A, L.; Romero H, S.; Chirino O, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Muhl S, S. [IIM-UNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    Films of hydrogenated amorphous carbon (a-C:H) were deposited using one source of microwave plasma with magnetic field (type ECR), using mixtures of H{sub 2}/CH{sub 4} in relationship of 80/20 and 95/05 as precursory gases, with work pressures of 4X10{sup -4} to 6x10{sup -4} Torr and an incident power of the discharge of microwaves with a constant value of 400 W. It was analyzed the influence among the properties of the films, as the deposit rate, the composition and the bonding types, and the deposit conditions, such as the flow rates of the precursory gases and the polarization voltage of the sample holders. (Author)

  8. Reduction of acid effects on trace element determination in food samples by CH4 mixed plasma-DRC-MS.

    Science.gov (United States)

    Guo, Wei; Hu, Shenghong; Zhang, Jiangyi; Hu, Zhaochu; Zhang, Hongfei; Wang, Yanxin

    2012-03-15

    A robust method for trace element determination in food samples by addition of methane to the plasma of a dynamic reaction cell mass spectrometer (CH(4) mixed plasma-DRC-MS) was developed. Addition of 3 mL min(-1) methane to Ar-plasma eliminates the signal suppressions of various elements (As, Se, Hg, etc.) due to the high concentration of nitric acid (10%, v/v). The CH(4)-Ar mixed plasma may compensate for the plasma cooling effects due to the highly concentrated nitric acid. The interfering polyatomic ions (40)Ar(12)C(+), (40)Ar(35)Cl(+) and (40)Ar(40)Ar(+) on (52)Cr(+), (75)As(+) and (80)Se(+) determination were removed effectively using the DRC with CH(4) as the reaction gas. The limits of quantification (LOQ, 10σ) were 0.35 ng g(-1), 0.07 ng g(-1), 0.35 ng g(-1), 0.07 ng g(-1), 0.15 ng g(-1), and 0.07 ng g(-1) for As, Cd, Cr, Hg, Pb and Se, respectively. The proposed method was applied to the determination of these trace elements in four food standard reference materials (NIST1577b, GBW10018, NIST1570a and GBW10016), and the results were in good agreement with the certified values.

  9. Solid-State 13C NMR Spectroscopy Applied to the Study of Carbon Blacks and Carbon Deposits Obtained by Plasma Pyrolysis of Natural Gas

    Directory of Open Access Journals (Sweden)

    Jair C. C. Freitas

    2016-01-01

    Full Text Available Solid-state 13C nuclear magnetic resonance (NMR spectroscopy was used in this work to analyze the physical and chemical properties of plasma blacks and carbon deposits produced by thermal cracking of natural gas using different types of plasma reactors. In a typical configuration with a double-chamber reactor, N2 or Ar was injected as plasma working gas in the first chamber and natural gas was injected in the second chamber, inside the arc column. The solid residue was collected at different points throughout the plasma apparatus and analyzed by 13C solid-state NMR spectroscopy, using either cross polarization (CP or direct polarization (DP, combined with magic angle spinning (MAS. The 13C CP/MAS NMR spectra of a number of plasma blacks produced in the N2 plasma reactor showed two resonance bands, broadly identified as associated with aromatic and aliphatic groups, with indication of the presence of oxygen- and nitrogen-containing groups in the aliphatic region of the spectrum. In contrast to DP experiments, only a small fraction of 13C nuclei in the plasma blacks are effectively cross-polarized from nearby 1H nuclei and are thus observed in spectra recorded with CP. 13C NMR spectra are thus useful to distinguish between different types of carbon species in plasma blacks and allow a selective study of groups spatially close to hydrogen in the material.

  10. Age-specific discrimination of blood plasma samples of healthy and ovarian cancer prone mice using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Melikechi, Noureddine; Markushin, Yuri; Connolly, Denise C.; Lasue, Jeremie; Ewusi-Annan, Ebo; Makrogiannis, Sokratis

    2016-09-01

    Epithelial ovarian cancer (EOC) mortality rates are strongly correlated with the stage at which it is diagnosed. Detection of EOC prior to its dissemination from the site of origin is known to significantly improve the patient outcome. However, there are currently no effective methods for early detection of the most common and lethal subtype of EOC. We sought to determine whether laser-induced breakdown spectroscopy (LIBS) and classification techniques such as linear discriminant analysis (LDA) and random forest (RF) could classify and differentiate blood plasma specimens from transgenic mice with ovarian carcinoma and wild type control mice. Herein we report results using this approach to distinguish blood plasma samples obtained from serially bled (at 8, 12, and 16 weeks) tumor-bearing TgMISIIR-TAg transgenic and wild type cancer-free littermate control mice. We have calculated the age-specific accuracy of classification using 18,000 laser-induced breakdown spectra of the blood plasma samples from tumor-bearing mice and wild type controls. When the analysis is performed in the spectral range 250 nm to 680 nm using LDA, these are 76.7 (± 2.6)%, 71.2 (± 1.3)%, and 73.1 (± 1.4)%, for the 8, 12 and 16 weeks. When the RF classifier is used, we obtain values of 78.5 (± 2.3)%, 76.9 (± 2.1)% and 75.4 (± 2.0)% in the spectral range of 250 nm to 680 nm, and 81.0 (± 1.8)%, 80.4 (± 2.1)% and 79.6 (± 3.5)% in 220 nm to 850 nm. In addition, we report, the positive and negative predictive values of the classification of the two classes of blood plasma samples. The approach used in this study is rapid, requires only 5 μL of blood plasma, and is based on the use of unsupervised and widely accepted multivariate analysis algorithms. These findings suggest that LIBS and multivariate analysis may be a novel approach for detecting EOC.

  11. Psychotropics and weak opioid analgesics in plasma samples of older hip fracture patients - detection frequencies and consistency with drug records.

    Science.gov (United States)

    Waade, Ragnhild Birkeland; Molden, Espen; Martinsen, Mette Irene; Hermann, Monica; Ranhoff, Anette Hylen

    2017-07-01

    To determine use of psychotropic drugs and weak opioids in hip fracture patients by analysing plasma samples at admission, and compare detected drug frequencies with prescription registry data and drug records. Plasma from 250 hip fracture patients aged ≥65 years sampled at hospital admission were analysed by ultra-performance liquid chromatography-tandem mass spectrometry methods for detection of psychotropic drugs and weak opioid analgesics (alcohol also determined). Odds ratios for drugs detected in plasma of hip fracture patients vs. prescription frequencies of the same drugs in an age-, time- and region-matched reference population were calculated. Moreover, recorded and measured drugs were compared. Psychotropic drugs and/or weak opioid analgesics were detected in 158 (63%) of the patients (median age 84 years; 76% females), while alcohol was found in 19 patients (7.6%). The occurrence of diazepam (odds ratio 1.6; 95% confidence interval 1.1-2.4), nitrazepam (2.3; 1.3-4.1), selective serotonin reuptake inhibitors (1.9; 1.3-2.9) and mirtazapine (2.3; 1.2-4.3) was significantly higher in plasma samples of hip fracture patients than in prescription data from the reference population. Poor consistency between recorded and measured drugs was disclosed for z-hypnotics and benzodiazepines; e.g. diazepam was detected in 29 (11.6%), but only recorded in six (2.4%) of the patients. Plasma analysis shows that use of antidepressants and benzodiazepines in hip fracture patients is significantly more frequent than respective prescription frequencies in the general elderly population. Moreover, consistency between recorded and actual use of psychotropic fall-risk drugs is poor at hospital admission of hip fracture patients. © 2017 The British Pharmacological Society.

  12. Comparison of the quantitative performances and measurement uncertainty estimates obtained during method validation versus routine applications of a novel hydrophilic interaction chromatography method for the determination of cidofovir in human plasma.

    Science.gov (United States)

    Lecomte, F; Hubert, C; Demarche, S; De Bleye, C; Dispas, A; Jost, M; Frankenne, F; Ceccato, A; Rozet, E; Hubert, Ph

    2012-01-05

    Method validation is essential to ensure that an analytical method is fit for its intended purpose. Additionally, it is advisable to estimate measurement uncertainty in order to allow a correct interpretation of the results generated by analytical methods. Measurement uncertainty can be efficiently estimated during method validation as a top-down approach. However, method validation predictions of the quantitative performances of the assay and estimations of measurement uncertainty may be far away from the real performances obtained during the routine application of this assay. In this work, the predictions of the quantitative performances and measurement uncertainty estimations obtained from a method validation are compared to those obtained during routine applications of a bioanalytical method. For that purpose, a new hydrophilic interaction chromatography (HILIC) method was used. This method was developed for the determination of cidofovir, an antiviral drug, in human plasma. Cidofovir (CDV) is a highly polar molecule presenting three ionizable functions. Therefore, it is an interesting candidate for determination by HILIC mode. CDV is an acyclic cytidine monophosphate analog that has a broad antiviral spectrum and is currently undergoing evaluation in clinical trials as a topical agent for treatment of papillomavirus infections. The analytical conditions were optimized by means of design of experiments approach in order to obtain robust analytical conditions. These ones were absolutely necessary to enable the comparisons mentioned above. After a sample clean-up by means of solid phase extraction, the chromatographic analysis was performed on bare silica stationary phase using a mixture of acetonitrile-ammonium hydrogen carbonate (pH 7.0; 20mM) (72:28, v/v) as mobile phase. This newly developed bioanalytical method was then fully validated according to FDA (Food and Drug Administration) requirements using a total error approach that guaranteed that each future

  13. Quantitative Fraction Evaluation of Dermal Collagen and Elastic Fibres in the Skin Samples Obtained in Two Orientations from the Trunk Region

    Directory of Open Access Journals (Sweden)

    Naveen Kumar

    2014-01-01

    Full Text Available Background. Histomorphic evaluation of dermal collagen and elastic fibres was analysed by image analysis technique. The quantification of dermal elements was performed in skin tissues, collected in horizontal and vertical directions from trunk region and discussed under the perspective of consequences of scar related complications. Materials and Method. Total number of 200 skin samples collected from 5 areas of trunk region were processed histologically and subjected to tissue-quant image analysis. Statistical analysis involving mean with SEM and paired t test by SPSS were employed to the percentage values obtained from image analysis. Result. Among the chosen 5 areas of trunk region, abdomen showed the statistically significant difference for both collagen and elastic content between horizontal and vertical orientations (P< 0.05, whereas upper back, presternal, and lateral chest areas showed significant difference (P< 0.05 only for collagen and groin only for elastic content. Conclusion. The differences in the distribution of dermal collagen and elastic fibres in 2 directions of the samples from the same areas might be attributed to final outcome of wound healing process by influencing the appearance and behaviour of scar related complications in the region of trunk.

  14. A rapid ultrasound-assisted dispersive liquid-liquid microextraction followed by ultra-performance liquid chromatography for the simultaneous determination of seven benzodiazepines in human plasma samples.

    Science.gov (United States)

    Fernández, Purificación; González, Cristina; Pena, M Teresa; Carro, Antonia M; Lorenzo, Rosa A

    2013-03-12

    A simple and efficient ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) method has been developed for the determination of seven benzodiazepines (alprazolam, bromazepam, clonazepam, diazepam, lorazepam, lormetazepam and tetrazepam) in human plasma samples. Chloroform and methanol were used as extractant and disperser solvents, respectively. The influence of several variables (e.g., type and volume of dispersant and extraction solvents, pH, ultrasonic time and ionic strength) was carefully evaluated and optimized, using an asymmetric screening design 3(2)4(2)//16. Analysis of extracts was performed by ultra-performance liquid chromatography coupled with photodiode array detection (UPLC-PDA). Under the optimum conditions, two reversed-phases, Shield RP18 and C18 columns were successfully tested, obtaining good linearity in a range of 0.01-5μgmL(-1), with correlation coefficients r>0.996. Quantification limits ranged between 4.3-13.2ngmL(-1) and 4.0-14.8ngmL(-1), were obtained for C18 and Shield RP18 columns, respectively. The optimized method exhibited a good precision level, with relative standard deviation values lower than 8%. The recoveries studied at two spiked levels, ranged from 71 to 102% for all considered compounds. The proposed method was successfully applied to the analysis of seven benzodiazepines in real human plasma samples.

  15. Pretreatment of plasma samples by a novel hollow fiber centrifugal ultrafiltrate device for the determination of cefaclor concentrations in human plasma.

    Science.gov (United States)

    Li, Jun-Mei; Li, Cen; Jiang, Ye; Ren, Shu-Meng

    2010-10-29

    A simple sample preparation method was developed by using a centrifugal ultrafiltration (CF-UF) device with hollow fiber (HF) for the determination of cefaclor in plasma by HPLC. Samples were placed into a homemade device, which was consisted of a glass tube and a U-shaped hollow fiber. The filtrate was withdrawn from the hollow fiber into a syringe after centrifugation and 20 μL was directly injected into the HPLC for analysis. The HPLC method had a linear calibration curve in the concentration range of 6.00×10(-2)-30.7 μg mL(-1)(r=0.9996). The limit of detection (LOD) and limit of quantitation (LOQ) were 0.02 and 0.06 μg mL(-1), respectively. The intra and inter-day precisions (RSD) were 1.7%, 1.2%, 1.0% and 3.6%, 2.5%, 1.9%, respectively, for three concentrations. Assay accuracy was higher than 99.2% and the absolute recovery was 86.8-92.5%. It is feasible to use this novel and low cost device for sample pretreatment for the analysis of cefaclor in plasma.

  16. Simulated Irradiation of Samples in HFIR for use as Possible Test Materials in the MPEX (Material Plasma Exposure Experiment) Facility

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, Ronald James [ORNL; Rapp, Juergen [ORNL

    2014-01-01

    The importance of Plasma Material Interaction (PMI) is a major concern in fusion reactor design and analysis. The Material-Plasma Exposure eXperiment (MPEX) facility will explore PMI under fusion reactor plasma conditions. Samples with accumulated displacements per atom (DPA) damage produced by irradiations in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) will be studied in the MPEX facility. The project presented in this paper involved performing assessments of the induced radioactivity and resulting radiation fields of a variety of potential fusion reactor materials. The scientific code packages MCNP and SCALE were used to simulate irradiation of the samples in HFIR; generation and depletion of nuclides in the material and the subsequent composition, activity levels, gamma radiation fields, and resultant dose rates as a function of cooling time. These state-of-the-art simulation methods were used in addressing the challenge of the MPEX project to minimize the radioactive inventory in the preparation of the samples for inclusion in the MPEX facility.

  17. Spark plasma sintering of Ti{sub y}Nb{sub 1-y}C{sub x}N{sub 1-x} monolithic ceramics obtained by mechanically induced self-sustaining reaction

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, Amparo, E-mail: aborrell@upvnet.upv.es [Instituto de Tecnologia de Materiales (ITM), Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Centro de Investigacion en Nanomateriales y Nanotecnologia (CINN) (Consejo Superior de Investigaciones Cientificas - Universidad de Oviedo - Principado de Asturias), Parque Tecnologico de Asturias, 33428 Llanera, Asturias (Spain); Salvador, Maria Dolores [Instituto de Tecnologia de Materiales (ITM), Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Garcia-Rocha, Victoria [ITMA Materials Technology, Parque Tecnologico de Asturias, 33428 Llanera (Asturias) (Spain); Fernandez, Adolfo [Centro de Investigacion en Nanomateriales y Nanotecnologia (CINN) (Consejo Superior de Investigaciones Cientificas - Universidad de Oviedo - Principado de Asturias), Parque Tecnologico de Asturias, 33428 Llanera, Asturias (Spain); ITMA Materials Technology, Parque Tecnologico de Asturias, 33428 Llanera (Asturias) (Spain); Chicardi, Ernesto; Gotor, Francisco J. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Calle Americo Vespucio 49, 41092 Sevilla (Spain)

    2012-05-01

    Nanometer-sized titanium-niobium carbonitride powders (Ti{sub y}Nb{sub 1-y}C{sub x}N{sub 1-x}) with different Ti/Nb atomic ratios were obtained by a mechanically induced self-sustaining reaction, and sintered by spark plasma sintering technique at 1500 Degree-Sign C for 1 min in a vacuum atmosphere. Mechanical properties such as hardness and Young's modulus were determined by nanoindentation technique and friction and wear coefficients assessed by ball-on-disk testing using alumina ball in dry sliding conditions. The fracture surface and wear tracks of samples were examined by scanning electron microscopy. Results showed that it is possible to obtain dense monolithic ceramics from the solid solution (Ti{sub y}Nb{sub 1-y}C{sub x}N{sub 1-x}) with good mechanical properties and excellent wear resistance. The optimum values of nanomechanical properties were found for the Ti{sub 0.3}Nb{sub 0.7}C{sub 0.5}N{sub 0.5} ceramic composition, which exhibited a high hardness over 26.0 GPa and Young's modulus around 400 GPa.

  18. Post-operative corticosterone levels in plasma and feces of mice subjected to permanent catheterization and automated blood sampling.

    Science.gov (United States)

    Sundbom, Renée; Jacobsen, Kirsten R; Kalliokoski, Otto; Hau, Jann; Abelson, Klas S P

    2011-01-01

    This study investigated the effects of surgical placement of permanent arterial catheters on plasma corticosterone levels, fecal corticosterone excretion and body weight in male BALB/c/Sca mice. In addition, the effects of voluntarily ingested buprenorphine in doses of 0.5 and 1.0 mg/kg body weight on these parameters were studied. A catheter was placed in the carotid artery during isoflurane anesthesia. Immediately after surgery, the mice were connected to an AccuSampler® μ and blood samples for plasma corticosterone quantification were collected automatically during the first 24 h postoperatively. All fecal boli produced 24 h before and 24 h after surgery were collected for fecal corticosterone excretion measures and the pre- and post-operative body weights were registered. Plasma corticosterone levels were in the range of 150-300 ng/ml after the surgical procedure and the body weight was significantly lower 24 h after surgery compared to its pre-operative value. Contrary to what was expected, the total fecal corticosterone excretion was significantly reduced 24 h after surgery, as was the defecation. Buprenorphine treatment significantly lowered the plasma corticosterone levels, but had no effect on fecal corticosterone excretion or body weight change. It was concluded that surgical placement of an arterial catheter induces a significant stress response, as judged by its effect on plasma corticosterone and body weight. Voluntary ingestion of buprenorphine improved postoperative recovery by lowering plasma corticosterone concentrations. Neither fecal corticosterone excretion nor body weight change seems suitable for postoperative stress assessment in mice in the present experimental setup.

  19. Multiple stage MS in analysis of plasma, serum, urine and in vitro samples relevant to clinical and forensic toxicology.

    Science.gov (United States)

    Meyer, Golo M; Maurer, Hans H; Meyer, Markus R

    2016-01-01

    This paper reviews MS approaches applied to metabolism studies, structure elucidation and qualitative or quantitative screening of drugs (of abuse) and/or their metabolites. Applications in clinical and forensic toxicology were included using blood plasma or serum, urine, in vitro samples, liquids, solids or plant material. Techniques covered are liquid chromatography coupled to low-resolution and high-resolution multiple stage mass analyzers. Only PubMed listed studies published in English between January 2008 and January 2015 were considered. Approaches are discussed focusing on sample preparation and mass spectral settings. Comments on advantages and limitations of these techniques complete the review.

  20. A Comparison between Ion chromatography and Inductively Coupled Plasma for the Determination of Bromate in Certain Samples of Foodstuffs

    Directory of Open Access Journals (Sweden)

    Alanowd O. Mehder

    2015-06-01

    Full Text Available Ion chromatography (IC and inductively coupled plasma (ICP-MS both were applied for the determination of bromate in some food samples. Attempts were made to establish calibration curves, however in case of IC, an additional abnormal peak was found to overlap with the bromate peak. This renders IC to be unsuccessful in the determination of bromate compared to ICP-MS technique. ICP-MS was found to give accurate results; therefore, it was applied for the determination of bromate in different samples of food stuffs.

  1. Determination of uranium isotopic composition and 236U content of soil samples and hot particles using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Boulyga, S F; Becker, J S

    2001-07-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The 236U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10(-4) and 10(-3) counts per atom were achieved for 238U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH+/U+ was 1.2 x 10(-4) and 1.4 x 10(-4), respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 microg L(-1) NBS U-020 standard solution was 0.11% (238U/235U) and 1.4% (236U/238U) using a MicroMist nebulizer and 0.25% (235U/238U) and 1.9% (236U/P38U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the 236U/238U ratio ranged from 10(-5) to 10(-3). Results obtained with ICP-MS, alpha- and gamma-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples.

  2. Multiplexed next-generation sequencing and de novo assembly to obtain near full-length HIV-1 genome from plasma virus.

    Science.gov (United States)

    Aralaguppe, Shambhu G; Siddik, Abu Bakar; Manickam, Ashokkumar; Ambikan, Anoop T; Kumar, Milner M; Fernandes, Sunjay Jude; Amogne, Wondwossen; Bangaruswamy, Dhinoth K; Hanna, Luke Elizabeth; Sonnerborg, Anders; Neogi, Ujjwal

    2016-10-01

    Analysing the HIV-1 near full-length genome (HIV-NFLG) facilitates new understanding into the diversity of virus population dynamics at individual or population level. In this study we developed a simple but high-throughput next generation sequencing (NGS) protocol for HIV-NFLG using clinical specimens and validated the method against an external quality control (EQC) panel. Clinical specimens (n=105) were obtained from three cohorts from two highly conserved HIV-1C epidemics (India and Ethiopia) and one diverse epidemic (Sweden). Additionally an EQC panel (n=10) was used to validate the protocol. HIV-NFLG was performed amplifying the HIV-genome (Gag-to-nef) in two fragments. NGS was performed using the Illumina HiSeq2500 after multiplexing 24 samples, followed by de novo assembly in Iterative Virus Assembler or VICUNA. Subtyping was carried out using several bioinformatics tools. Amplification of HIV-NFLG has 90% (95/105) success-rate in clinical specimens. NGS was successful in all clinical specimens (n=45) and EQA samples (n=10) attempted. The mean error for mutations for the EQC panel viruses were <1%. Subtyping identified two as A1C recombinant. Our results demonstrate the feasibility of a simple NGS-based HIV-NFLG that can potentially be used in the molecular surveillance for effective identification of subtypes and transmission clusters for operational public health intervention.

  3. Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)

    Science.gov (United States)

    Wolf, Ruth E.; Adams, Monique

    2015-01-01

    Typically, quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine as many as 57 major, minor, and trace elements in aqueous geochemical samples, including natural surface water and groundwater, acid mine drainage water, and extracts or leachates from geological samples. The sample solution is aspirated into the inductively coupled plasma (ICP) which is an electrodeless discharge of ionized argon gas at a temperature of approximately 6,000 degrees Celsius. The elements in the sample solution are subsequently volatilized, atomized, and ionized by the ICP. The ions generated are then focused and introduced into a quadrupole mass filter which only allows one mass to reach the detector at a given moment in time. As the settings of the mass analyzer change, subsequent masses are allowed to impact the detector. Although the typical quadrupole ICP-MS system is a sequential scanning instrument (determining each mass separately), the scan speed of modern instruments is on the order of several thousand masses per second. Consequently, typical total sample analysis times of 2–3 minutes are readily achievable for up to 57 elements.

  4. Determination of cadmium, mercury and lead in coal fly ash by slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.C.; Jiang, S.J. [National Sun Yat Sen University, Kaohsiung (Taiwan). Dept. of Chemistry

    1999-08-09

    Ultrasonic slurry sampling electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry (USS-ETV-ID-ICP-MS) was used to the determine Cd, Hg and Pb in coal fly ash samples. Thioacetamide (TAC) was the modifier. Since the sensitivities of the elements studied in coal fly ash slurry and aqueous solution were quite different, isotope dilution method was used for the determination of Cd, Hg and Pb in the coal fly ash samples. The isotope ratios of each element were calculated from the peak areas of each injection peak. This method was applied to the determination of Cd, Hg and Pb in NIST SRM 1633a coal fly ash reference material and a coal fly ash sample collected from Kaohsiung area. Detection limits estimated from standard addition curves were in the range of 24-58, 6-28 and 108-110 ng g{sup -1} for Cd, Hg and Pb, respectively.

  5. Novel system using microliter order sample volume for measuring arterial radioactivity concentrations in whole blood and plasma for mouse PET dynamic study.

    Science.gov (United States)

    Kimura, Yuichi; Seki, Chie; Hashizume, Nobuya; Yamada, Takashi; Wakizaka, Hidekatsu; Nishimoto, Takahiro; Hatano, Kentaro; Kitamura, Keishi; Toyama, Hiroshi; Kanno, Iwao

    2013-11-21

    This study aimed to develop a new system, named CD-Well, for mouse PET dynamic study. CD-Well allows the determination of time-activity curves (TACs) for arterial whole blood and plasma using 2-3 µL of blood per sample; the minute sample size is ideal for studies in small animals. The system has the following merits: (1) measures volume and radioactivity of whole blood and plasma separately; (2) allows measurements at 10 s intervals to capture initial rapid changes in the TAC; and (3) is compact and easy to handle, minimizes blood loss from sampling, and delay and dispersion of the TAC. CD-Well has 36 U-shaped channels. A drop of blood is sampled into the opening of the channel and stored there. After serial sampling is completed, CD-Well is centrifuged and scanned using a flatbed scanner to define the regions of plasma and blood cells. The length measured is converted to volume because the channels have a precise and uniform cross section. Then, CD-Well is exposed to an imaging plate to measure radioactivity. Finally, radioactivity concentrations are computed. We evaluated the performance of CD-Well in in vitro measurement and in vivo (18)F-fluorodeoxyglucose and [(11)C]2-carbomethoxy-3β-(4-fluorophenyl) tropane studies. In in vitro evaluation, per cent differences (mean±SE) from manual measurement were 4.4±3.6% for whole blood and 4.0±3.5% for plasma across the typical range of radioactivity measured in mouse dynamic study. In in vivo studies, reasonable TACs were obtained. The peaks were captured well, and the time courses coincided well with the TAC derived from PET imaging of the heart chamber. The total blood loss was less than 200 µL, which had no physiological effect on the mice. CD-Well demonstrates satisfactory performance, and is useful for mouse PET dynamic study.

  6. A column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry method to determine anandamide and 2-arachidonoylglycerol in plasma samples.

    Science.gov (United States)

    Marchioni, Camila; de Souza, Israel Donizeti; Grecco, Caroline Fernandes; Crippa, José Alexandre; Tumas, Vitor; Queiroz, Maria Eugênia Costa

    2017-05-01

    This study reports a fast, sensitive, and selective column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine the endocannabinoids (eCBs), anandamide (AEA), and 2-arachidonoylglycerol (2-AG) in plasma samples. This bidimensional system used a restricted access media column (RP-8 ADS, 25 mm × 4 mm × 25 μM) in the first dimension and a core-shell Kinetex C18 (100 mm × 2, 1.7 mm × 1 μM) column in the second dimension, followed by detection in a mass spectrometer triple quadrupole (multiple reactions monitoring mode) operating in the positive mode. RP-8 ADS was used for trace enrichment of eCBs (reverse phase partitioning) and macromolecular matrix size exclusion; the core-shell column was used for the chromatographic separation. The column switching UHPLC-MS/MS method presented a linear range spanning from 0.1 ng mL(-1) (LOQ) to 6 ng mL(-1) for AEA and from 0.04 ng mL(-1) (LOQ) to 10 ng mL(-1) for 2-AG. Excluding the LLOQ values, the precision assays provided coefficients of variation lower than 8% and accuracy with relative standard error values lower than 14%. Neither carryover nor matrix effects were detected. This high-throughput column switching method compared to conventional methods is time saving as it involves fewer steps, consumes less solvent, and presents lower LLOQ. The column switching UHPLC-MS/MS method was successfully applied to determine AEA and 2-AG in plasma samples obtained from Alzheimer's disease patients. Graphical abstract A column switching ultra high-performance liquid chromatography-tandem mass spectrometry method using RP-8 ADS column and core shell column to determine endocannabinoids in plasma samples.

  7. Method of Electrolyte-Plasma Surface Hardening of 65G and 20GL Low-Alloy Steels Samples

    Science.gov (United States)

    Rakhadilov, Bauyrzhan; Zhurerova, Laila; Pavlov, Alexander

    2016-08-01

    This work is devoted to formation of modified surface layers in 65G and 20GL steels which using for the manufacture of railway transport parts, as well as the study of influence of the parametersof electrolyte-plasma surface hardening methodon the changes in structural-phase states, improving of wear-resistance. The process of electrolyte-plasma surface hardening of 65G and 20GL steels samples conducted in the electrolyte from water solution of 20% sodium carbonate, in the mode ~850°C - 2 seconds, ∼⃒1200°C - 3 seconds. It is established that in the initial state 20GL steel has ferrite-pearlite structure, and the 60G steel consists of pearlite and cement structure. After application of electrolyte-plasma surface hardening is observed the formation of carbides particles and martensite phase components in the structure of 20GL and 60G steels. It is determined that after electrolyte-plasma surface hardening with heating time - 2 seconds, the abrasive wear-resistance of 65G and 20GL steels increased to 1.3 times and 1.2 times, respectively, and the microhardness is increased to 1.6 times and 1.3 times, respectively.

  8. Rapid determination of piracetam in human plasma and cerebrospinal fluid by micellar electrokinetic chromatography with sample direct injection.

    Science.gov (United States)

    Yeh, Hsin-Hua; Yang, Yuan-Han; Ko, Ju-Yun; Chen, Su-Hwei

    2006-07-07

    A simple micellar electrokinetic chromatography (MEKC) method with UV detection at 200 nm for analysis of piracetam in plasma and in cerebrospinal fluid (CSF) by direct injection without any sample pretreatment is described. The separation of piracetam from biological matrix was performed at 25 degrees C using a background electrolyte consisting of Tris buffer with sodium dodecyl sulfate (SDS) as the electrolyte solution. Several parameters affecting the separation of the drug from biological matrix were studied, including the pH and concentrations of the Tris buffer and SDS. Under optimal MEKC condition, good separation with high efficiency and short analyses time is achieved. Using imidazole as an internal standard (IS), the linear ranges of the method for the determination of piracetam in plasma and in CSF were all between 5 and 500 microg/mL; the detection limit of the drug in plasma and in CSF (signal-to-noise ratio=3; injection 0.5 psi, 5s) was 1.0 microg/mL. The applicability of the proposed method for determination of piracetam in plasma and CSF collected after intravenous administration of 3g piracetam every 6h and oral administration 1.2g every 6h in encephalopathy patients with aphasia was demonstrated.

  9. Evaluation of volatile profiles obtained for minimally-processed pineapple fruit samples during storage by headspace-solid phase microextraction gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Francielle Crocetta TURAZZI

    Full Text Available Abstract This paper describes the application of the solid-phase microextraction (SPME technique for the determination and monitoring of the volatile profile of minimally-processed pineapple fruit stored at various temperatures (-12 °C, 4 °C and 25 °C for different periods (1, 4 and 10 days. The SPME fiber coating composed of Car/PDMS presented the best performance. The optimal extraction conditions obtained through a Doehlert design were 60 min at 35 °C. The profiles for the volatile compounds content of the fruit at each stage of storage were determined by gas chromatography-mass spectrometry (GC-MS. The variation in the volatile profile over time was greater when the fruit samples were stored at 25 °C and at -12 °C compared to 4 °C. Thus, according to the volatile profiles associated with the storage conditions evaluated in this study, packaged pineapple retains best its fresh fruit aroma when stored at 4 °C.

  10. Liquid-based cytological test of samples obtained by catheter aspiration is applicable for the bronchoscopic confirmation of pulmonary malignant tumors

    Science.gov (United States)

    Li, Dai-Rong; Wan, Tao; Su, Yi; Ding, Min; Wu, Jin-Xing; Zhao, Yong

    2014-01-01

    The aim of the present study is to confirm the value of electronic bronchoscopy-aided catheter aspiration technique with liquid-based cytological test in the diagnosis of bronchogenic carcinoma. A total of 815 patients of lung cancer were evaluated by bronchoscopy between February 2011 and June 2012. Catheter aspiration technique and forceps biopsy during bronchoscopy were employed to obtain adequate tissue specimens. Liquid-based cytological test and conventional smears for catheter aspiration were used for cytological detection of the tumors. For all cytological specimens, slide preparations with LCT and CS were reviewed by two senior pathologists, who were blinded to patient medical history. Complications related to electronic bronchoscopy, such as bleeding, were clinically judged as light, moderate or severe by the needs for clinical interventions. The diagnostic yield of catheter aspiration in endobronchial visible lesions (tumor, infiltrative and necrotic lesions) was 94.6% (success rates concerning malignancy), which was slightly higher than that of the forceps biopsy (91.4%, P biopsy (51.4%, P biopsy with the cytological analysis of the catheter aspiration increased the diagnostic sensitivity in both lesion types (P biopsy. Liquid-based cytological test is routinely applicable for the diagnosis of lung cancer using samples collected through electronic bronchoscopy. PMID:24966963

  11. pH adjustment of human blood plasma prior to bioanalytical sample preparation

    NARCIS (Netherlands)

    Hendriks, G.; Uges, D. R. A.; Franke, J. P.

    2008-01-01

    pH adjustment in bioanalytical sample preparation concerning ionisable compounds is one of the most common sample treatments. This is often done by mixing an aliquot of the sample with a proper buffer adjusted to the proposed pH. The pH of the resulting mixture however, does not necessarily have to

  12. New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry. Progress report, January 1, 1990--December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Montaser, A.

    1992-09-01

    New high temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. Emphasis was placed on atmospheric pressure He inductively coupled plasmas (ICP) suitable for atomization, excitation, and ionization of elements; simulation and computer modeling of plasma sources with potential for use in spectrochemical analysis; spectroscopic imaging and diagnostic studies of high temperature plasmas, particularly He ICP discharges; and development of new, low-cost sample introduction systems, and examination of techniques for probing the aerosols over a wide range. Refs., 14 figs. (DLC)

  13. Effects of Low-Temperature Plasma-Sterilization on Mars Analog Soil Samples Mixed with Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Janosch Schirmack

    2016-05-01

    Full Text Available We used Ar plasma-sterilization at a temperature below 80 °C to examine its effects on the viability of microorganisms when intermixed with tested soil. Due to a relatively low temperature, this method is not thought to affect the properties of a soil, particularly its organic component, to a significant degree. The method has previously been shown to work well on spacecraft parts. The selected microorganism for this test was Deinococcus radiodurans R1, which is known for its remarkable resistance to radiation effects. Our results showed a reduction in microbial counts after applying a low temperature plasma, but not to a degree suitable for a sterilization of the soil. Even an increase of the treatment duration from 1.5 to 45 min did not achieve satisfying results, but only resulted in in a mean cell reduction rate of 75% compared to the untreated control samples.

  14. Effects of Low-Temperature Plasma-Sterilization on Mars Analog Soil Samples Mixed with Deinococcus radiodurans

    Science.gov (United States)

    Schirmack, Janosch; Fiebrandt, Marcel; Stapelmann, Katharina; Schulze-Makuch, Dirk

    2016-01-01

    We used Ar plasma-sterilization at a temperature below 80 °C to examine its effects on the viability of microorganisms when intermixed with tested soil. Due to a relatively low temperature, this method is not thought to affect the properties of a soil, particularly its organic component, to a significant degree. The method has previously been shown to work well on spacecraft parts. The selected microorganism for this test was Deinococcus radiodurans R1, which is known for its remarkable resistance to radiation effects. Our results showed a reduction in microbial counts after applying a low temperature plasma, but not to a degree suitable for a sterilization of the soil. Even an increase of the treatment duration from 1.5 to 45 min did not achieve satisfying results, but only resulted in in a mean cell reduction rate of 75% compared to the untreated control samples. PMID:27240407

  15. Particle transport in a He-microchip plasma atomic emission system with an ultrasonic nebulizer for aqueous sample introduction

    Science.gov (United States)

    Oh, Joosuck; Lim, H. B.

    2008-11-01

    The transport efficiency of dried particles generated from an ultrasonic nebulizer (USN) was studied to improve the analytical performance of a lab-made, He-microchip plasma system, in which a quartz tube (~ 1 mm i.d.) was positioned inside the central channel of a poly(dimethylsiloxane) (PDMS) polymer chip. The polymer microchip plasma has the advantages of low cost, small size, easy handling and design, and self-ignition with long stabilization (> 24 h). However, direct introduction of aqueous solution into the microplasma for the detection of metals remains problematic due to plasma instability. In addition, the much smaller size of the system can cause signal suppression due to low transport efficiency. Therefore, knowledge of particle transport efficiency in this microplasma system is required to enhance the sensitivity and stability. The weight of transported particles in the range of 0.02 to 10 mg m - 3 was measured using a piezobalance with a precision of 0.4-17.8%, depending on the operating conditions. The significant effects of the USN operating conditions and the physical properties of the tubing, namely, length, inner diameter and surface characteristics, on the number of particles transported from the nebulizer to the microplasma were studied. When selected metals, such as Na, Mg and Pb, at a concentration of 5 mg L - 1 were nebulized, transported particles were obtained with a mass range of 0.5-5 mg m - 3 , depending on atomic weights. For application of the He-rf-microplasma, the atomic emission system was optimized by changing both the radio frequency (rf) power (60-200 W) and cooling temperature of the USN (- 12-9 °C). The limits of detection obtained for K, Na and Cu were 0.26, 0.22, and 0.28 mg L - 1 , respectively. These results confirmed the suitable stability and sensitivity of the He-rf-PDMS microchip plasma for application as an atomization source.

  16. High plasma corticosterone levels persist during frequent automatic blood sampling in rats

    DEFF Research Database (Denmark)

    Abelson, Klas S P; Adem, Bashir; Royo, Felix

    2005-01-01

    Corticosterone levels in blood may be used as a marker of stress in rodents, provided that the blood sampling procedure itself is non-stressful. Automated blood sampling equipment (Accusampler) allows blood sampling without any interference with the animal and might be useful as a tool for an on...... the importance of considering the frequency of blood withdrawal during automated blood sampling. This parameter may have an impact on the experimental results when using blood corticosterone levels as a stress marker, but also during any in vivo study where blood is collected, since high corticosterone levels...... may affect the normal physiology of the animals....

  17. Detection and genotyping of human papillomavirus in self-obtained cervicovaginal samples by using the FTA cartridge: new possibilities for cervical cancer screening.

    NARCIS (Netherlands)

    Lenselink, C.H.; Bie, R.P. de; Hamont, D. van; Bakkers, J.M.J.E.; Quint, W.G.V.; Massuger, L.F.A.G.; Bekkers, R.L.M.; Melchers, W.J.G.

    2009-01-01

    This study assesses human papillomavirus (HPV) detection and genotyping in self-sampled genital smears applied to an indicating FTA elute cartridge (FTA cartridge). The study group consisted of 96 women, divided into two sample sets. All samples were analyzed by the HPV SPF(10)-Line Blot 25. Set 1

  18. Polymer coatings on plane and spherical surfaces obtained by plasma polymerization from trans-2-butene and hydrogen mixture; Depots de polymere sur surfaces planes et spheriques obtenus par polymerisation plasma a partir d`un melange de trans-2-butene et d`hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Benardais, A

    1997-10-21

    This study of a low frequency plasma polymerization process was undertaken to be used in manufacturing of targets used in laser-matter interaction experiments. In this system, whether the sample is placed in the discharge or outside of the discharge, hydrocarbon coatings from a gaseous mixture of hydrogen and trans-2-butene are obtain. This study consists of two parts. We first dealt with the understanding of plasma polymerization mechanisms in the reactor which resulted in a better process optimization. The study of gas flow in the reactor allowed us to determine the species repartition in the vessel. With experiments performed on the electrical behavior in the reactor we were able to define the discharge type. Then, species present in the plasma were analysed by emission spectroscopy and mass spectrometry and then reaction mechanisms were proposed. Attention was paid to the role of hydrogen which in fact acted as a reagent like trans-2-butene. We also worked on the process optimization in order to obtain a good working point which produces coatings which are as transparent as possible, contain only carbon and hydrogen (and the least amount of oxygen), have a smooth surface finish (mean square root of roughness < 50 nm) and retain their qualities overtime. After the reactor characterization, the study of the effects of different parameters (inner or post-discharge coatings, pressure, total gas flow, composition of the mixture of trans-2-butene and hydrogen, power, frequency, interelectrode distance) on deposition rate, roughness and chemical composition of coatings led to the finding of optimal deposition conditions. (author) 103 refs.

  19. Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ying; Shi, Zeming; Zong, Qinxia; Wu, Peng; Su, Jing [Sichuan Provincial Key Laboratory of Nuclear Technology in Geology, College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China); Liu, Rui, E-mail: liur.ray@gmail.com [Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2014-02-17

    Graphical abstract: -- Highlights: •Simple, sensitive, and accurate method is established for mercury determination in cosmetics. •The sample preparation procedure is highly simplified. •Isotope dilution efficiently eliminates matrix effect. •First report of using formic acid based method in combination with PVG-ID-ICP MS for mercury quantitation in cosmetics. -- Abstract: A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched {sup 201}Hg isotopic spike is added to cosmetics and the isotope ratios of {sup 201}Hg/{sup 202}Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL{sup −1}. Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.

  20. An environmentally-friendly, highly efficient, gas pressure-assisted sample introduction system for ICP-MS and its application to detection of cadmium and lead in human plasma.

    Science.gov (United States)

    Cao, Yupin; Deng, Biyang; Yan, Lizhen; Huang, Hongli

    2017-05-15

    An environmentally friendly and highly efficient gas pressure-assisted sample introduction system (GPASIS) was developed for inductively-coupled plasma mass spectrometry. A GPASIS consisting of a gas-pressure control device, a customized nebulizer, and a custom-made spray chamber was fabricated. The advantages of this GPASIS derive from its high nebulization efficiencies, small sample volume requirements, low memory effects, good precision, and zero waste emission. A GPASIS can continuously, and stably, nebulize 10% NaCl solution for more than an hour without clogging. Sensitivity, detection limits, precision, long-term stability, double charge and oxide ion levels, nebulization efficiencies, and matrix effects of the sample introduction system were evaluated. Experimental results indicated that the performance of this GPASIS, was equivalent to, or better than, those obtained by conventional sample introduction systems. This GPASIS was successfully used to determine Cd and Pb by ICP-MS in human plasma. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Post-glucose-load urinary C-peptide and glucose concentration obtained during OGTT do not affect oral minimal model-based plasma indices

    NARCIS (Netherlands)

    S. Jainandunsing (Sjaam); J.L.D. Wattimena (Josias); T. Rietveld (Trinet); J.N.I. van Miert (Joram); E.J.G. Sijbrands (Eric); F.W.M. de Rooij (Felix)

    2016-01-01

    textabstractThe purpose of this study was to investigate how renal loss of both C-peptide and glucose during oral glucose tolerance test (OGTT) relate to and affect plasma-derived oral minimal model (OMM) indices. All individuals were recruited during family screening between August 2007 and January

  2. Effect of additional sample bias in Meshed Plasma Immersion Ion Deposition (MPIID) on microstructural, surface and mechanical properties of Si-DLC films

    Science.gov (United States)

    Wu, Mingzhong; Tian, Xiubo; Li, Muqin; Gong, Chunzhi; Wei, Ronghua

    2016-07-01

    Meshed Plasma Immersion Ion Deposition (MPIID) using cage-like hollow cathode discharge is a modified process of conventional PIID, but it allows the deposition of thick diamond-like carbon (DLC) films (up to 50 μm) at a high deposition rate (up to 6.5 μm/h). To further improve the DLC film properties, a new approach to the MPIID process is proposed, in which the energy of ions incident to the sample surface can be independently controlled by an additional voltage applied between the samples and the metal meshed cage. In this study, the meshed cage was biased with a pulsed DC power supply at -1350 V peak voltage for the plasma generation, while the samples inside the cage were biased with a DC voltage from 0 V to -500 V with respect to the cage to study its effect. Si-DLC films were synthesized with a mixture of Ar, C2H2 and tetramethylsilane (TMS). After the depositions, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectrons spectroscopy (XPS), Raman spectroscopy and nanoindentation were used to study the morphology, surface roughness, chemical bonding and structure, and the surface hardness as well as the modulus of elasticity of the Si-DLC films. It was observed that the intense ion bombardment significantly densified the films, reduced the surface roughness, reduced the H and Si contents, and increased the nanohardness (H) and modulus of elasticity (E), whereas the deposition rate decreased slightly. Using the H and E data, high values of H3/E2 and H/E were obtained on the biased films, indicating the potential excellent mechanical and tribological properties of the films. In this paper, the effects of the sample bias voltage on the film properties are discussed in detail and the optimal bias voltage is presented.

  3. Systematic Review of the Performance of HIV Viral Load Technologies on Plasma Samples

    Science.gov (United States)

    Sollis, Kimberly A.; Smit, Pieter W.; Fiscus, Susan; Ford, Nathan; Vitoria, Marco; Essajee, Shaffiq; Barnett, David; Cheng, Ben; Crowe, Suzanne M.; Denny, Thomas; Landay, Alan; Stevens, Wendy; Habiyambere, Vincent; Perrins, Jos; Peeling, Rosanna W.

    2014-01-01

    Background Viral load (VL) monitoring is the standard of care in developing country settings for detecting HIV treatment failure. Since 2010 the World Health Organization has recommended a phase-in approach to VL monitoring in resource-limited settings. We conducted a systematic review of the accuracy and precision of HIV VL technologies for treatment monitoring. Methods and Findings A search of Medline and Embase was conducted for studies evaluating the accuracy or reproducibility of commercially available HIV VL assays. 37 studies were included for review including evaluations of the Amplicor Monitor HIV-1 v1.5 (n = 25), Cobas TaqMan v2.0 (n = 11), Abbott RealTime HIV-1 (n = 23), Versant HIV-1 RNA bDNA 3.0 (n = 15), Versant HIV-1 RNA kPCR 1.0 (n = 2), ExaVir Load v3 (n = 2), and NucliSens EasyQ v2.0 (n = 1). All currently available HIV VL assays are of sufficient sensitivity to detect plasma virus levels at a lower detection limit of 1,000 copies/mL. Bias data comparing the Abbott RealTime HIV-1, TaqMan v2.0 to the Amplicor Monitor v1.5 showed a tendency of the Abbott RealTime HIV-1 to under-estimate results while the TaqMan v2.0 overestimated VL counts. Compared to the Amplicor Monitor v1.5, 2–26% and 9–70% of results from the Versant bDNA 3.0 and Abbott RealTime HIV-1 differed by greater than 0.5log10. The average intra and inter-assay variation of the Abbott RealTime HIV-1 were 2.95% (range 2.0–5.1%) and 5.44% (range 1.17–30.00%) across the range of VL counts (2log10–7log10). Conclusions This review found that all currently available HIV VL assays are of sufficient sensitivity to detect plasma VL of 1,000 copies/mL as a threshold to initiate investigations of treatment adherence or possible treatment failure. Sources of variability between VL assays include differences in technology platform, plasma input volume, and ability to detect HIV-1 subtypes. Monitoring of individual patients should be performed on the same

  4. Systematic review of the performance of HIV viral load technologies on plasma samples.

    Directory of Open Access Journals (Sweden)

    Kimberly A Sollis

    Full Text Available BACKGROUND: Viral load (VL monitoring is the standard of care in developing country settings for detecting HIV treatment failure. Since 2010 the World Health Organization has recommended a phase-in approach to VL monitoring in resource-limited settings. We conducted a systematic review of the accuracy and precision of HIV VL technologies for treatment monitoring. METHODS AND FINDINGS: A search of Medline and Embase was conducted for studies evaluating the accuracy or reproducibility of commercially available HIV VL assays. 37 studies were included for review including evaluations of the Amplicor Monitor HIV-1 v1.5 (n = 25, Cobas TaqMan v2.0 (n = 11, Abbott RealTime HIV-1 (n = 23, Versant HIV-1 RNA bDNA 3.0 (n = 15, Versant HIV-1 RNA kPCR 1.0 (n = 2, ExaVir Load v3 (n = 2, and NucliSens EasyQ v2.0 (n = 1. All currently available HIV VL assays are of sufficient sensitivity to detect plasma virus levels at a lower detection limit of 1,000 copies/mL. Bias data comparing the Abbott RealTime HIV-1, TaqMan v2.0 to the Amplicor Monitor v1.5 showed a tendency of the Abbott RealTime HIV-1 to under-estimate results while the TaqMan v2.0 overestimated VL counts. Compared to the Amplicor Monitor v1.5, 2-26% and 9-70% of results from the Versant bDNA 3.0 and Abbott RealTime HIV-1 differed by greater than 0.5log10. The average intra and inter-assay variation of the Abbott RealTime HIV-1 were 2.95% (range 2.0-5.1% and 5.44% (range 1.17-30.00% across the range of VL counts (2log10-7log10. CONCLUSIONS: This review found that all currently available HIV VL assays are of sufficient sensitivity to detect plasma VL of 1,000 copies/mL as a threshold to initiate investigations of treatment adherence or possible treatment failure. Sources of variability between VL assays include differences in technology platform, plasma input volume, and ability to detect HIV-1 subtypes. Monitoring of individual patients should be performed on the same

  5. Determination of cadmium, mercury and lead in coal fly ash by slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Liao, Hsien-Chung; Jiang, Shiuh-Jen

    1999-08-01

    Ultrasonic slurry sampling electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry (USS-ETV-ID-ICP-MS) has been applied to the determination of Cd, Hg and Pb in coal fly ash samples. Thioacetamide (TAC) was used as the modifier. Since the sensitivities of the elements studied in coal fly ash slurry and aqueous solution were quite different, isotope dilution method was used for the determination of Cd, Hg and Pb in these coal fly ash samples. The isotope ratios of each element were calculated from the peak areas of each injection peak. This method has been applied to the determination of Cd, Hg and Pb in NIST SRM 1633a coal fly ash reference material and a coal fly ash sample collected from Kaohsiung area. Analysis results of reference sample NIST SRM 1633a coal fly ash agreed satisfactorily with the certified values. The other sample determined by isotope dilution and method of standard additions was agreed satisfactorily. Precision was better than 6% for most of the determinations and accuracy was better than 4% with the USS-ETV-ID-ICP-MS method. Detection limits estimated from standard addition curves were in the range of 24-58, 6-28 and 108-110 ng g-1 for Cd, Hg and Pb, respectively.

  6. Analysis of Elemental and Isotopic Composition of a Substance Obtained in Experiments on Energy Concentration in a Solid-State Superdense Plasma

    CERN Document Server

    Adamenko, S V

    2003-01-01

    We present the results of the experimental study on synthesis of a wide range of isotopes in a superdense plasma. The initial conditions necessary for plasma bunch formation were provided by specially organized coherent impact on a solid target with a total energy up to 1 kJ. More than 4000 shots were performed with various targets made of light, medium, and heavy elements. Subsequent analysis of the products of the target explosion reveals the presence of a wide range of elements absent in the initial materials. Elements with nuclei three and more times heavier than the nucleus of the target main element are detected in the products. The isotopic composition of the produced elements significantly differs from the natural one. The presence of unknown superheavy elements at the border of the periodic table and beyond it was detected by several different spectroscopic methods of elemental and isotopic analyzes.

  7. Monitoring of cefepime in human serum and plasma by micellar electrokinetic capillary chromatography: Improvement of sample preparation and validation by liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Šestáková, Nela; Theurillat, Regula; Sendi, Parham; Thormann, Wolfgang

    2017-02-20

    Cefepime monitoring in deproteinized human serum and plasma by micellar electrokinetic capillary chromatography and liquid chromatography coupled to mass spectrometry in presence of other drugs is reported. For micellar electrokinetic capillary chromatography, sample preparation comprised dodecylsulfate protein precipitation at pH 4.5 using an increased buffer concentration compared to that of a previous assay and removal of hydrophobic compounds with dichloromethane. This provided robust conditions for cefepime analysis in the presence of sulfamethoxazole and thus enabled its determination in samples of patients that receive co-trimoxazole. The liquid chromatography assay is based upon use of a column with a pentafluorophenyl-propyl modified and multi-endcapped stationary phase and the coupling to electrospray ionization with a single quadrupole detector. The performances of both assays with multi-level internal calibration were assessed with calibration and control samples and both assays were determined to be robust. Cefepime levels monitored by micellar electrokinetic capillary chromatography in samples from patients that were treated with cefepime only and with cefepime and co-trimoxazole were found to compare well with those obtained by liquid chromatography coupled to mass spectrometry. Cefepime drug levels determined by micellar electrokinetic capillary chromatography could thereby be validated. This article is protected by copyright. All rights reserved.

  8. TL and OSL dose response and stability properties of various commercially glass samples obtained from Turkey for dosimetric purposes in the UV emission spectral region.

    Science.gov (United States)

    Şahiner, Eren

    2017-10-01

    This paper reports Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) dose response characteristics of ten different commercial glass samples collected from Turkey. Nowadays, glass samples are widely used mostly in objects of everyday life. The study focuses to both TL and OSL dose responses, through a dose region within 1 and 512Gy. Lowest detectable dose limit (LDDL) as well as the respective linearity features of the corresponding dose response curves were studied for both TL and OSL. Moreover, signal reproducibility and fading behaviors have also been studied in detail. For specific samples, the lowest detectable dose was yielded at 2Gy, making thus these samples appropriate for retrospective dosimetry applications. Nevertheless, based on the features reported in the present study, the majority of the samples could be possibly used effectively for dosimetric applications of higher doses in the UV region emission. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Determination of extremely low (236)U/(238)U isotope ratios in environmental samples by sector-field inductively coupled plasma mass spectrometry using high-efficiency sample introduction.

    Science.gov (United States)

    Boulyga, Sergei F; Heumann, Klaus G

    2006-01-01

    A method by inductively coupled plasma mass spectrometry (ICP-MS) was developed which allows the measurement of (236)U at concentration ranges down to 3 x 10(-14)g g(-1) and extremely low (236)U/(238)U isotope ratios in soil samples of 10(-7). By using the high-efficiency solution introduction system APEX in connection with a sector-field ICP-MS a sensitivity of more than 5,000 counts fg(-1) uranium was achieved. The use of an aerosol desolvating unit reduced the formation rate of uranium hydride ions UH(+)/U(+) down to a level of 10(-6). An abundance sensitivity of 3 x 10(-7) was observed for (236)U/(238)U isotope ratio measurements at mass resolution 4000. The detection limit for (236)U and the lowest detectable (236)U/(238)U isotope ratio were improved by more than two orders of magnitude compared with corresponding values by alpha spectrometry. Determination of uranium in soil samples collected in the vicinity of Chernobyl nuclear power plant (NPP) resulted in that the (236)U/(238)U isotope ratio is a much more sensitive and accurate marker for environmental contamination by spent uranium in comparison to the (235)U/(238)U isotope ratio. The ICP-MS technique allowed for the first time detection of irradiated uranium in soil samples even at distances more than 200 km to the north of Chernobyl NPP (Mogilev region). The concentration of (236)U in the upper 0-10 cm soil layers varied from 2 x 10(-9)g g(-1) within radioactive spots close to the Chernobyl NPP to 3 x 10(-13)g g(-1) on a sampling site located by >200 km from Chernobyl.

  10. Comparison of a high temperature torch integrated sample introduction system with a desolvation system for the analysis of microsamples through inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Sánchez, Raquel; Cañabate, Águeda; Bresson, Carole; Chartier, Frédéric; Isnard, Hélène; Maestre, Salvador; Nonell, Anthony; Todolí, José-Luis

    2017-03-01

    This work describes for the first time the comparison of the analytical performances obtained with a high temperature torch integrated sample introduction system (hTISIS) against those found with a commercially available desolvation system (APEX) associated with inductively coupled plasma mass spectrometry (ICP-MS). A double pass spray chamber was taken as the reference system. Similar detection limits and sensitivities were obtained in continuous injection mode at low liquid flow rates for the APEX and hTISIS operating at high temperatures. In contrast, in the air-segmented injection mode, the detection limits obtained with hTISIS at high temperatures were up to 12 times lower than those found for the APEX. Regarding memory effects, wash out times were shorter in continuous mode and peaks were narrower in air segmented mode for the hTISIS as compared to the APEX. Non spectral interferences (matrix effects) were studied with 10% nitric acid, 2% methanol, for an ICP multielemental solution and a hydro-organic matrix containing 70% (v/v) acetonitrile in water, 15 mmol L- 1 ammonium acetate and 0.5% formic acid containing lanthanide complexes. In all the cases, matrix effects were less severe for the hTISIS operating at 200 °C and the APEX than for the double pass spray chamber. Finally, two spiked reference materials (sea water and Antartic krill) were analyzed. The hTISIS operating at 200 °C gave the best results compared to those obtained with the APEX and the double pass spray chamber. In conclusion, despite the simplicity of the hTISIS, it provided, at low liquid flow rates, results similar to or better than those obtained with the by other sample introduction systems.

  11. Production of aerosols by optical catapulting: Imaging, performance parameters and laser-induced plasma sampling rate

    Science.gov (United States)

    Abdelhamid, M.; Fortes, F. J.; Fernández-Bravo, A.; Harith, M. A.; Laserna, J. J.

    2013-11-01

    Optical catapulting (OC) is a sampling and manipulation method that has been extensively studied in applications ranging from single cells in heterogeneous tissue samples to analysis of explosive residues in human fingerprints. Specifically, analysis of the catapulted material by means of laser-induced breakdown spectroscopy (LIBS) offers a promising approach for the inspection of solid particulate matter. In this work, we focus our attention in the experimental parameters to be optimized for a proper aerosol generation while increasing the particle density in the focal region sampled by LIBS. For this purpose we use shadowgraphy visualization as a diagnostic tool. Shadowgraphic images were acquired for studying the evolution and dynamics of solid aerosols produced by OC. Aluminum silicate particles (0.2-8 μm) were ejected from the substrate using a Q-switched Nd:YAG laser at 1064 nm, while time-resolved images recorded the propagation of the generated aerosol. For LIBS analysis and shadowgraphy visualization, a Q-switched Nd:YAG laser at 1064 nm and 532 nm was employed, respectively. Several parameters such as the time delay between pulses and the effect of laser fluence on the aerosol production have been also investigated. After optimization, the particle density in the sampling focal volume increases while improving the aerosol sampling rate till ca. 90%.

  12. Comparative Investigation between In Situ Laser Ablation Versus Bulk Sample (Solution Mode) Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Analysis of Trinitite Post-Detonation Materials.

    Science.gov (United States)

    Dustin, Megan K; Koeman, Elizabeth C; Simonetti, Antonio; Torrano, Zachary; Burns, Peter C

    2016-09-01

    In the event of the interception of illicit nuclear materials or detonation of a nuclear device, timely and accurate deciphering of the chemical and isotopic composition of pertinent samples is pivotal in enhancing both nuclear security and source attribution. This study reports the results from a first time (to our knowledge), detailed comparative investigation conducted of Trinitite post-detonation materials using both solution mode (SM) and laser ablation (LA) inductively coupled plasma mass spectrometry (ICP-MS) techniques. Trace element abundances determined for bulk Trinitite samples subsequent to digestion and preparation for SM-ICP-MS analysis compare favorably to calculated median concentrations based on LA-ICP-MS analyses for the identical samples. The trace element concentrations obtained by individual LA-ICP-MS analyses indicate a large scatter compared to the corresponding bulk sample SM-ICP-MS results for the same sample; this feature can be attributed to the incorporation into the blast melt of specific, precursor accessory minerals (minerals in small quantities, such as carbonates, sulfates, chlorites, clay, and mafic minerals) present at ground zero. The favorable comparison reported here validates and confirms the use of the LA-ICP-MS technique in obtaining accurate forensic information at high spatial resolution in nuclear materials for source attribution purposes. This investigation also reports device-like (240)Pu/(239)Pu ratios (∼0.022) for Pu-rich regions of the blast melt that are also characterized by higher Ca and U contents, which is consistent with results from previous studies. © The Author(s) 2016.

  13. Recent advances in hydrophilic interaction chromatography for quantitative analysis of endogenous and pharmaceutical compounds in plasma samples.

    Science.gov (United States)

    Isokawa, Muneki; Kanamori, Takahiro; Funatsu, Takashi; Tsunoda, Makoto

    2014-09-01

    There is an increasing need for new analytical methods that can handle a large number of analytes in complex matrices. Hydrophilic interaction chromatography (HILIC) has recently been demonstrated as an important supplement to reversed-phase liquid chromatography for polar analytes, particularly endogenous compounds. With the increasing popularity of HILIC, progressively more polar phases with diverse functional groups have been developed. In addition, the coupling of HILIC to mass spectrometry offers the advantages of improved sensitivity by employing an organic-rich mobile phase. This article reviews recent applications of HILIC for the analysis of endogenous and pharmaceutical compounds in plasma samples. Furthermore, based on recent studies, we provide a discussion of column selection, sample pretreatment for HILIC analysis, and detection sensitivity.

  14. Determination of tamoxifen and its main metabolites in plasma samples from breast cancer patients by micellar liquid chromatography.

    Science.gov (United States)

    Peris-Vicente, Juan; Ochoa-Aranda, Enrique; Bose, Devasish; Esteve-Romero, Josep

    2015-01-01

    A method was developed for the analysis of tamoxifen and its main derivatives (4-hydroxytamoxifen, N-desmethyl-tamoxifen, tamoxifen-N-oxide and endoxifen) in human plasma, using micellar liquid chromatography coupled with fluorescence detection. Analytes were off-line derivatized by sample UV-irradiation for 20 min to form the photocycled fluorescent derivatives. Then samples were diluted, filtered and directly injected, thus avoiding extraction steps. The analytes were resolved using a mobile phase containing 0.08 M SDS-4.5% butanol at pH 3 running at 1.5 mL/min through a C18 column at 40°C, without interferences from endogenous compounds in plasma. Excitation and emission wavelengths were 260 and 380 nm, respectively. The chromatographic analysis time was less than 40 min. The analytical methodology was validated following the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines in terms of: selectivity, linear range (0.3-15 μg/mL), linearity (r(2)>0.999), sensitivity (LOD, 65-80 ng/mL; LOQ, 165-200 ng/mL), intra- and interday accuracy (-12.2-11.5%) and precision (<9.2%) and robustness (<6.3%). The method was used to quantify the tamoxifen and tamoxifen derivatives in several breast cancer patients from a local hospital, in order to study the correlation between the genotype of the patient and the ability to metabolize tamoxifen.

  15. Plasma treatment of bulk niobium surface for superconducting rf cavities: Optimization of the experimental conditions on flat samples

    Directory of Open Access Journals (Sweden)

    M. Rašković

    2010-11-01

    Full Text Available Accelerator performance, in particular the average accelerating field and the cavity quality factor, depends on the physical and chemical characteristics of the superconducting radio-frequency (SRF cavity surface. Plasma based surface modification provides an excellent opportunity to eliminate nonsuperconductive pollutants in the penetration depth region and to remove the mechanically damaged surface layer, which improves the surface roughness. Here we show that the plasma treatment of bulk niobium (Nb presents an alternative surface preparation method to the commonly used buffered chemical polishing and electropolishing methods. We have optimized the experimental conditions in the microwave glow discharge system and their influence on the Nb removal rate on flat samples. We have achieved an etching rate of 1.7  μm/min⁡ using only 3% chlorine in the reactive mixture. Combining a fast etching step with a moderate one, we have improved the surface roughness without exposing the sample surface to the environment. We intend to apply the optimized experimental conditions to the preparation of single cell cavities, pursuing the improvement of their rf performance.

  16. Evaluation of superficially porous and fully porous columns for analysis of drugs in plasma samples by UHPLC-MS/MS.

    Science.gov (United States)

    Acquaro, Vinicius Ricardo; Lanças, Fernando Mauro; Queiroz, Maria Eugênia Costa

    2017-03-24

    This work compares the performance of recently introduced C18 superficially porous columns (four columns) and C18 fully porous columns (two columns), with different particle sizes, during the analysis of drugs in plasma samples by MS/MS detection. The following chromatographic parameters were evaluated for all the columns: reduced plate height (h) vs reduced linear velocity (v), impedance vs v, chromatographic run time vs flow rate (mLmin(-1)), backpressure vs flow rate (mLmin(-1)), resolution, peak capacity, asymmetry, and retention factor. By using DAD detection, hydrophobicity, silanol activity, and metal impurities were also assessed for the columns. The columns with charged surface displayed improved chromatographic efficiency for the drugs in their ionized form. The columns with particles smaller than 2μm (Cortecs 1.6μm, Acquity 1.7μm, and Kinetex 1.7μm) presented higher chromatographic efficiency for the drugs, which were in their partially ionized form. The generated mathematical models were able to predict the backpressure and chromatographic run time at different flow rates for all the columns. Considering the efficiency, impedance, resolution, peak capacity, retention factor, and hydrophobicity, Cortecs 1.6μm and Acquity 1.7μm were the columns that given the best performance during analysis of the target drugs in plasma samples.

  17. Handheld analyzer with on-chip molecularly-imprinted biosensors for electrical detection of propofol in plasma samples.

    Science.gov (United States)

    Hong, Chien-Chong; Lin, Chih-Chung; Hong, Chian-Lang; Lin, Zi-Xiang; Chung, Meng-Hua; Hsieh, Pei-Wen

    2016-12-15

    This paper proposes a novel handheld analyzer with disposable lab-on-a-chip technology for the electrical detection of the anesthetic propofol in human plasma samples for clinical diagnoses. The developed on-chip biosensors are based on the conduction of molecularly imprinted polymers (MIPs) that employ label-free electrical detection techniques. Propofol in total intravenous anesthesia is widely used with a target-controlled infusion system. At present, the methods employed for detecting blood propofol concentrations in hospitals comprise high-performance liquid chromatography and ion mobility spectrometry. These conventional instruments are bulky, expensive, and difficult to access. In this study, we developed a novel plastic microfluidic biochip with an on-chip anesthetic biosensor that was characterized for the rapid detection of propofol concentrations. The experimental results revealed that the response time of the developed propofol biosensors was 25s. The specific binding of an MIP to a nonimprinted polymer (NIP) reached up to 560%. Moreover, the detection limit of the biosensors was 0.1μg/mL, with a linear detection range of 0.1-30μg/mL. The proposed disposable microfluidic biochip with an on-chip anesthetic biosensor using MIPs exhibited excellent performance in the separation and sensing of propofol molecules in the human plasma samples. Compared with large-scale conventional instruments, the developed microfluidic biochips with on-chip MIP biosensors present the advantages of a compact size, high selectivity, low cost, rapid response, and single-step detection.

  18. Evaluation of a cost effective in-house method for HIV-1 drug resistance genotyping using plasma samples.

    Directory of Open Access Journals (Sweden)

    Devidas N Chaturbhuj

    Full Text Available OBJECTIVES: Validation of a cost effective in-house method for HIV-1 drug resistance genotyping using plasma samples. DESIGN: The validation includes the establishment of analytical performance characteristics such as accuracy, reproducibility, precision and sensitivity. METHODS: The accuracy was assessed by comparing 26 paired Virological Quality Assessment (VQA proficiency testing panel sequences generated by in-house and ViroSeq Genotyping System 2.0 (Celera Diagnostics, US as a gold standard. The reproducibility and precision were carried out on five samples with five replicates representing multiple HIV-1 subtypes (A, B, C and resistance patterns. The amplification sensitivity was evaluated on HIV-1 positive plasma samples (n = 88 with known viral loads ranges from 1000-1.8 million RNA copies/ml. RESULTS: Comparison of the nucleotide sequences generated by ViroSeq and in-house method showed 99.41±0.46 and 99.68±0.35% mean nucleotide and amino acid identity respectively. Out of 135 Stanford HIVdb listed HIV-1 drug resistance mutations, partial discordance was observed at 15 positions and complete discordance was absent. The reproducibility and precision study showed high nucleotide sequence identities i.e. 99.88±0.10 and 99.82±0.20 respectively. The in-house method showed 100% analytical sensitivity on the samples with HIV-1 viral load >1000 RNA copies/ml. The cost of running the in-house method is only 50% of that for ViroSeq method (112$ vs 300$, thus making it cost effective. CONCLUSIONS: The validated cost effective in-house method may be used to collect surveillance data on the emergence and transmission of HIV-1 drug resistance in resource limited countries. Moreover, the wide applications of a cost effective and validated in-house method for HIV-1 drug resistance testing will facilitate the decision making for the appropriate management of HIV infected patients.

  19. Routine use of microarray-based gene expression profiling to identify patients with low cytogenetic risk acute myeloid leukemia: accurate results can be obtained even with suboptimal samples.

    Science.gov (United States)

    de la Blétière, Diane Raingeard; Blanchet, Odile; Cornillet-Lefèbvre, Pascale; Coutolleau, Anne; Baranger, Laurence; Geneviève, Franck; Luquet, Isabelle; Hunault-Berger, Mathilde; Beucher, Annaelle; Schmidt-Tanguy, Aline; Zandecki, Marc; Delneste, Yves; Ifrah, Norbert; Guardiola, Philippe

    2012-01-30

    Gene expression profiling has shown its ability to identify with high accuracy low cytogenetic risk acute myeloid leukemia such as acute promyelocytic leukemia and leukemias with t(8;21) or inv(16). The aim of this gene expression profiling study was to evaluate to what extent suboptimal samples with low leukemic blast load (range, 2-59%) and/or poor quality control criteria could also be correctly identified. Specific signatures were first defined so that all 71 acute promyelocytic leukemia, leukemia with t(8;21) or inv(16)-AML as well as cytogenetically normal acute myeloid leukemia samples with at least 60% blasts and good quality control criteria were correctly classified (training set). The classifiers were then evaluated for their ability to assign to the expected class 111 samples considered as suboptimal because of a low leukemic blast load (n = 101) and/or poor quality control criteria (n = 10) (test set). With 10-marker classifiers, all training set samples as well as 97 of the 101 test samples with a low blast load, and all 10 samples with poor quality control criteria were correctly classified. Regarding test set samples, the overall error rate of the class prediction was below 4 percent, even though the leukemic blast load was as low as 2%. Sensitivity, specificity, negative and positive predictive values of the class assignments ranged from 91% to 100%. Of note, for acute promyelocytic leukemia and leukemias with t(8;21) or inv(16), the confidence level of the class assignment was influenced by the leukemic blast load. Gene expression profiling and a supervised method requiring 10-marker classifiers enable the identification of favorable cytogenetic risk acute myeloid leukemia even when samples contain low leukemic blast loads or display poor quality control criterion.

  20. Development of novel and sensitive methods for the determination of sulfide in aqueous samples by hydrogen sulfide generation-inductively coupled plasma-atomic emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Colon, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, J.L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Hidalgo, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Iglesias, M. [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain)], E-mail: monica.iglesias@udg.es

    2008-02-25

    Two new, simple and accurate methods for the determination of sulfide (S{sup 2-}) at low levels ({mu}g L{sup -1}) in aqueous samples were developed. The generation of hydrogen sulfide (H{sub 2}S) took place in a coil where sulfide reacted with hydrochloric acid. The resulting H{sub 2}S was then introduced as a vapor into an inductively coupled plasma-atomic emission spectrometer (ICP-AES) and sulfur emission intensity was measured at 180.669 nm. In comparison to when aqueous sulfide was introduced, the introduction of sulfur as H{sub 2}S enhanced the sulfur signal emission. By setting a gas separator at the end of the reaction coil, reduced sulfur species in the form of H{sub 2}S were removed from the water matrix, thus, interferences could be avoided. Alternatively, the gas separator was replaced by a nebulizer/spray chamber combination to introduce the sample matrix and reagents into the plasma. This methodology allowed the determination of both sulfide and sulfate in aqueous samples. For both methods the linear response was found to range from 5 {mu}g L{sup -1} to 25 mg L{sup -1} of sulfide. Detection limits of 5 {mu}g L{sup -1} and 6 {mu}g L{sup -1} were obtained with and without the gas separator, respectively. These new methods were evaluated by comparison to the standard potentiometric method and were successfully applied to the analysis of reduced sulfur species in environmental waters.

  1. Thallium Analysis in Environmental Samples by Inductively Coupled Plasma Mass Spectrometry; Analisis de Talio en Muestras Ambientales por Espectrometria de Masas con Fuente de Plasma de Acoplamiento Inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Higueras, I.; Fernandez, M.; Conde, E.; Gajate, A.

    2008-08-06

    Due to its high toxicity, thallium has been considered by the US Environmental Protection Agency as one of the priority pollutants to be controlled. While being a highly toxic element, thallium has been studied to a much lesser degree than other toxic elements, mainly because thallium is often undetected by classical analytical methods. Thallium is a rare and dispersed element that occurs mainly in sulfur-containing ores. Thus, it is a potential pollutant to surrounding environment, if Tl-rich mineral and/or their industrial wastes are not properly disposed. In this work an Inductively Coupled Plasma Mass Spectrometry analytical procedure has been developed in order to determine thallium in environmental solid samples and its application to the study of this element as a potential pollutant associated with natural and anthropogenic activities. The analytical procedure has been validated by the use of appropriate reference materials, and through the isotope dilution technique as a primary method of measurement. Finally, the developed procedure has been applied to several samples from a mining area, as one of the scenarios where thallium it is likely to occur. (Author) 87 refs.

  2. Effect of additional sample bias in Meshed Plasma Immersion Ion Deposition (MPIID) on microstructural, surface and mechanical properties of Si-DLC films

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mingzhong [State Key Laboratory of Advanced Welding & Joining, Harbin Institute of Technology, Harbin 150001 (China); School of Materials Science & Engineering, Jiamusi University, Jiamusi 154007 (China); Tian, Xiubo, E-mail: xiubotian@163.com [State Key Laboratory of Advanced Welding & Joining, Harbin Institute of Technology, Harbin 150001 (China); Li, Muqin [School of Materials Science & Engineering, Jiamusi University, Jiamusi 154007 (China); Gong, Chunzhi [State Key Laboratory of Advanced Welding & Joining, Harbin Institute of Technology, Harbin 150001 (China); Wei, Ronghua [Southwest Research Institute, San Antonio, TX 78238 (United States)

    2016-07-15

    Highlights: • A novel Meshed Plasma Immersion Ion Deposition is proposed. • The deposited Si-DLC films possess denser structures and high deposition rate. • It is attributed to ion bombardment of the deposited films. • The ion energy can be independently controlled by an additional bias (novel set up). - Abstract: Meshed Plasma Immersion Ion Deposition (MPIID) using cage-like hollow cathode discharge is a modified process of conventional PIID, but it allows the deposition of thick diamond-like carbon (DLC) films (up to 50 μm) at a high deposition rate (up to 6.5 μm/h). To further improve the DLC film properties, a new approach to the MPIID process is proposed, in which the energy of ions incident to the sample surface can be independently controlled by an additional voltage applied between the samples and the metal meshed cage. In this study, the meshed cage was biased with a pulsed DC power supply at −1350 V peak voltage for the plasma generation, while the samples inside the cage were biased with a DC voltage from 0 V to −500 V with respect to the cage to study its effect. Si-DLC films were synthesized with a mixture of Ar, C{sub 2}H{sub 2} and tetramethylsilane (TMS). After the depositions, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectrons spectroscopy (XPS), Raman spectroscopy and nanoindentation were used to study the morphology, surface roughness, chemical bonding and structure, and the surface hardness as well as the modulus of elasticity of the Si-DLC films. It was observed that the intense ion bombardment significantly densified the films, reduced the surface roughness, reduced the H and Si contents, and increased the nanohardness (H) and modulus of elasticity (E), whereas the deposition rate decreased slightly. Using the H and E data, high values of H{sup 3}/E{sup 2} and H/E were obtained on the biased films, indicating the potential excellent mechanical and tribological properties of the films. In this

  3. Increased levels of HIV RNA detected in samples with viral loads close to the detection limit collected in Plasma Preparation Tubes (PPT).

    Science.gov (United States)

    Griffith, Brigitte P; Mayo, Donald R

    2006-02-01

    The accurate and reliable quantification of HIV RNA is an essential part of the management of HIV infected individuals, and elucidation of factors that may affect HIV RNA measurements, such as the use of Vacutainer Plasma Preparation Tubes (PPT), is crucial. The objective of this study was to determine if plasma samples with viral loads close to the lower limit of the dynamic range of the assay collected in PPT tubes had increased levels of HIV RNA as compared to samples collected in standard EDTA tubes. HIV RNA levels were compared in 112 paired plasma samples collected in PPT and standard EDTA tubes. All samples had been frozen prior to testing. Discrepancies between PPT and EDTA tubes did not occur for samples with high viral loads. However, in samples with viral loads close to the lower limit of the dynamic range, levels of HIV RNA detected were higher in a large proportion of PPT as compared to the corresponding EDTA plasma samples. Forty percent of plasma pairs had no detectable HIV RNA in the EDTA aliquot, but had low levels of HIV RNA in the corresponding PPT aliquot. This prospective study underlines the need for cautious interpretation of small transient viral load changes in samples with values close to the detection limit.

  4. Simultaneous determination of trimethylamine and trimethylamine N-oxide in mouse plasma samples by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Mi, Si; Zhao, Yuan-Yuan; Jacobs, René L; Curtis, Jonathan M

    2017-02-01

    A method was developed that applies hydrophilic interaction liquid chromatography with tandem mass spectrometry in the multiple reaction monitoring mode to separate and accurately quantify trimethylamine and trimethylamine N-oxide in a single chromatographic run. This was achieved by converting trimethylamine to ethyl betaine, which is less volatile and hence results in greatly improved quantitation. Ethyl betaine also gives a similar response to trimethylamine N-oxide using positive-ion electrospray ionization mass spectrometry. It is readily separated from trimethylamine N-oxide by hydrophilic liquid chromatography in a 5 min run and with improved peak shape compared to underivatized trimethylamine. Validation of the method yielded a limit of detection (S/N ≥ 3) of 0.5 ng/mL for trimethylamine and 0.25 ng/mL for trimethylamine N-oxide. Method accuracies of 91.4-105.3% with precisions of 0.4-5.5% were obtained for standard mixtures over the range of 2.5-500 ng/mL. Recoveries measured for the extraction of trimethylamine and trimethylamine N-oxide spikes into mouse plasma were both >90%. The method, which simultaneously measures trimethylamine and trimethylamine N-oxide, was successfully applied to mouse plasma samples and could be adapted for use with other biological fluids.

  5. PFAS concentrations in plasma samples from Danish school children and their mothers

    DEFF Research Database (Denmark)

    Mørck, Thit Aarøe; Nielsen, Flemming; Nielsen, Jeanette Kolstrup Søgaard

    2015-01-01

    Perfluoroalkyl substances (PFASs) are accumulating in our environment and human exposure to these potentially harmful chemicals are of growing concern. In the present study, 116 children aged 6–11 and 143 mothers in two locations in Denmark donated blood samples as a supplement to their participa......Perfluoroalkyl substances (PFASs) are accumulating in our environment and human exposure to these potentially harmful chemicals are of growing concern. In the present study, 116 children aged 6–11 and 143 mothers in two locations in Denmark donated blood samples as a supplement......-PFOS and total-PFOS were significantly higher in children compared to their mothers. This may be due to higher exposure in children through for example dust and soil, and due to the fact that children are smaller in body size and blood volume and hence have a lower storage capacity. Furthermore, we found...

  6. Development of a Fibrinogen-Specific Sandwich Enzyme-Linked Immunosorbent Assay Microarray Assay for Distinguishing Between Blood Plasma and Serum Samples

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, Rachel M.; Zhang, Qibin; Zangar, Richard C.; Smith, Richard D.; Metz, Thomas O.

    2011-07-01

    We have developed a fibrinogen-specific sandwich ELISA microarray assay for use in qualitatively distinguishing between blood plasma and serum samples. Three capture antibodies, 49D2, HPA001900, and F8512, were evaluated in conjunction with 1D6 as detection antibody, and the data show that 49D2 and, to a lesser extent, F8512 successfully identify previously unknown plasma and serum samples based upon a ~28-fold difference in signal intensity between the sample types. This assay has utility in rapidly identifying previously archived clinical samples with incomplete annotation in a high throughput manner prior to proteomics analyses.

  7. Particle transport in a He-microchip plasma atomic emission system with an ultrasonic nebulizer for aqueous sample introduction

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Joosuck [Department of Chemistry, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do, 448-701 (Korea, Republic of); Lim, H.B. [Department of Chemistry, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do, 448-701 (Korea, Republic of)], E-mail: plasma@dankook.ac.kr

    2008-11-15

    The transport efficiency of dried particles generated from an ultrasonic nebulizer (USN) was studied to improve the analytical performance of a lab-made, He-microchip plasma system, in which a quartz tube ({approx} 1 mm i.d.) was positioned inside the central channel of a poly(dimethylsiloxane) (PDMS) polymer chip. The polymer microchip plasma has the advantages of low cost, small size, easy handling and design, and self-ignition with long stabilization (> 24 h). However, direct introduction of aqueous solution into the microplasma for the detection of metals remains problematic due to plasma instability. In addition, the much smaller size of the system can cause signal suppression due to low transport efficiency. Therefore, knowledge of particle transport efficiency in this microplasma system is required to enhance the sensitivity and stability. The weight of transported particles in the range of 0.02 to 10 mg m{sup -3} was measured using a piezobalance with a precision of 0.4-17.8%, depending on the operating conditions. The significant effects of the USN operating conditions and the physical properties of the tubing, namely, length, inner diameter and surface characteristics, on the number of particles transported from the nebulizer to the microplasma were studied. When selected metals, such as Na, Mg and Pb, at a concentration of 5 mg L{sup -1} were nebulized, transported particles were obtained with a mass range of 0.5-5 mg m{sup -3}, depending on atomic weights. For application of the He-rf-microplasma, the atomic emission system was optimized by changing both the radio frequency (rf) power (60-200 W) and cooling temperature of the USN (- 12-9 deg. C). The limits of detection obtained for K, Na and Cu were 0.26, 0.22, and 0.28 mg L{sup -1}, respectively. These results confirmed the suitable stability and sensitivity of the He-rf-PDMS microchip plasma for application as an atomization source.

  8. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Ni [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Jiang, Shiuh-Jen, E-mail: sjjiang@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Chen, Yen-Ling [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Sahayam, A.C. [National Centre for Compositional Characterisation of Materials (CCCM), Hyderabad (India)

    2015-02-20

    Highlights: • Determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions in a single run. • Accurate analysis using isotope dilution and standard addition methods. • Vapor generation ICP-MS yielded superior detection limits compared to ETV-ICP-MS. • No sample dissolution increased sample through put. • Analysis of GBW09305 Cosmetic (Cream) reference material for accuracy. - Abstract: A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL{sup −1} Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g{sup −1} for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample.

  9. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions.

    Science.gov (United States)

    Weber, Daniela; Davies, Michael J; Grune, Tilman

    2015-08-01

    Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple different reactive oxygen species in blood, tissues and cells. Sample preparation and stabilization are key steps in the accurate quantification of oxidation-related products and examination of physiological/pathological processes. This review therefore focuses on the sample preparation processes used in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples.

  10. Comparison of selenium determination in liver samples by atomic absorption spectroscopy and inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Miksa, Irina Rudik; Buckley, Carol L; Carpenter, Nancy P; Poppenga, Robert H

    2005-07-01

    Selenium (Se) is an essential trace element that is often deficient in the natural diets of domestic animal species. The measurement of Se in whole blood or liver is the most accurate way to assess Se status for diagnostic purposes. This study was conducted to compare hydride generation atomic absorption spectroscopy (HG-AAS) with inductively coupled plasma-mass spectrometry (ICP-MS) for the detection and quantification of Se in liver samples. Sample digestion was accomplished with magnesium nitrate and nitric acid for HG-AAS and ICP-MS, respectively. The ICP-MS detection was optimized for 82Se with yttrium used as the internal standard and resulted in a method detection limit of 0.12 microg/g. Selenium was quantified by both methods in 310 samples from a variety of species that were submitted to the Toxicology Laboratory at New Bolton Center (Kennett Square, PA) for routine diagnostic testing. Paired measurements for each sample were evaluated by a mean difference plot method. Limits of agreement were used to describe the maximum differences likely to occur between the 2 methods. Results suggest that under the specified conditions ICP-MS can be reliably used in place of AAS for quantitation of tissue Se at or below 2 microg/g to differentiate between adequate and deficient liver Se concentrations.

  11. Comparison of laser ablation and dried solution aerosol as sampling systems in inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Coedo, A G; Padilla, I; Dorado, M T

    2004-12-01

    This paper describes a study designed to determine the possibility of using a dried aerosol solution for calibration in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The relative sensitivities of tested materials mobilized by laser ablation and by aqueous nebulization were established, and the experimentally determined relative sensitivity factors (RSFs) were used in conjunction with aqueous calibration for the analysis of solid steel samples. To such a purpose a set of CRM carbon steel samples (SS-451/1 to SS-460/1) were sampled into an ICP-MS instrument by solution nebulization using a microconcentric nebulizer with membrane desolvating (D-MCN) and by laser ablation (LA). Both systems were applied with the same ICP-MS operating parameters and the analyte signals were compared. The RSF (desolvated aerosol response/ablated solid response) values were close to 1 for the analytes Cr, Ni, Co, V, and W, about 1.3 for Mo, and 1.7 for As, P, and Mn. Complementary tests were carried out using CRM SS-455/1 as a solid standard for one-point calibration, applying LAMTRACE software for data reduction and quantification. The analytical results are in good agreement with the certified values in all cases, showing that the applicability of dried aerosol solutions is a good alternative calibration system for laser ablation sampling.

  12. A micro-fluidic sub-microliter sample introduction system for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry using external aqueous calibration

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Heyong [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China); Liu, Jinhua [College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China); Xu, Zigang [Institute of Analytical and Applied Chemistry, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); Yin, Xuefeng, E-mail: yinxf@zju.edu.cn [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China)

    2012-07-15

    A microfluidic sub-microliter sample introducing system was developed for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry (ICP-MS). It consisted of a microfluidic chip integrating variable-volume sampling channels (0.1-0.8 {mu}L), an eight-way multi-functional valve used in flow injection analysis (FIA), a syringe pump and a peristaltic pump of the Ar ICP-MS instrument. Three solutions, i.e., 15, 40 and 100 g L{sup -1} glucose in 20% ethanol were used to simulate Chinese rice wine of the dry type, the semidry type and the semisweet type, each. The effects of their volume introduced into ICP-MS on the plasma stability and ICP-MS intensities were studied. The experimental results showed that neither alteration of plasma stability nor carbon deposition was observed when the sampling volume of 20% ethanol containing 100 g L{sup -1} glucose was downscaled to 0.8 {mu}L. Further reducing the sampling volume to 0.4 {mu}L, no significant difference between the intensities of multi-element standard prepared in three simulated Chinese rice wine matrices and those in aqueous solution was observed. It indicated no negative effect of Chinese rice wine matrix on the ICP-MS intensities. A sampling volume of 0.4 {mu}L was considered to be a good compromise between sensitivity and matrix effect. The flow rate of the carrier was chosen as 20 {mu}L min{sup -1} for obtaining peaks with the highest peak height within the shortest time. Based on these observations, a microflow injection ({mu}FI) method for the direct determination of cadmium and lead in Chinese rice wine by ICP-MS using an external aqueous calibration was developed. The sample throughput was 45 h{sup -1} with the detection limit of 19.8 and 10.4 ng L{sup -1} for Cd and Pb, respectively. The contents of Cd and Pb in 10 Chinese rice wine samples were measured. The results agreed well with those determined by ICP-MS with the conventional sampling system after microwave assisted digestion

  13. A high-throughput method for the conversion of CO2 obtained from biochemical samples to graphite in septa-sealed vials for quantification of 14C via accelerator mass spectrometry.

    Science.gov (United States)

    Ognibene, Ted J; Bench, Graham; Vogel, John S; Peaslee, Graham F; Murov, Steve

    2003-05-01

    The growth of accelerator mass spectrometry as a tool for quantitative isotope ratio analysis in the biosciences necessitates high-throughput sample preparation. A method has been developed to convert CO(2) obtained from carbonaceous samples to solid graphite for highly sensitive and precise (14)C quantification. Septa-sealed vials are used along with commercially available disposable materials, eliminating sample cross contamination, minimizing complex handling, and keeping per sample costs low. Samples containing between 0.25 and 10 mg of total carbon can be reduced to graphite in approximately 4 h in routine operation. Approximately 150 samples per 8-h day can be prepared by a single technician.

  14. Detection of foot-and-mouth disease virus RNA in pharyngeal epithelium biopsy samples obtained from infected cattle: Investigation of possible sites of virus replication and persistence

    DEFF Research Database (Denmark)

    Stenfeldt, Anna Carolina; Belsham, Graham

    2012-01-01

    was used to investigate the level of FMDV RNA present at this site at sequential time points during the infection. Results were compared to measurements of virus excretion in samples of oropharyngeal fluid collected at corresponding time points. Possible sites of virus persistence were investigated through...... measurements of the levels of FMDV RNA in the DSP as well as mandibular and retropharyngeal lymph nodes beyond 28 days after infection. Results indicated only low levels of FMDV RNA present in samples of pharyngeal epithelia during both early and persistent phases of infection with significantly higher levels...

  15. Speciation of mercury in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Jia, Xiaoyu; Han, Yi; Liu, Xinli; Duan, Taicheng; Chen, Hangting

    2011-01-01

    The dispersive liquid-liquid microextraction (DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry for the speciation of mercury in water samples was described. Firstly methylmercury (MeHg +) and mercury (Hg 2+) were complexed with sodium diethyldithiocarbamate, and then the complexes were extracted into carbon tetrachloride by using DLLME. Under the optimized conditions, the enrichment factors of 138 and 350 for MeHg + and Hg 2+ were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 0.0076 ng mL -1 for MeHg + and 0.0014 ng mL -1 for Hg 2+, respectively. The relative standard deviations for ten replicate measurements of 0.5 ng mL -1 MeHg + and Hg 2+ were 6.9% and 4.4%, respectively. Standard reference material of seawater (GBW(E)080042) was analyzed to verify the accuracy of the method and the results were in good agreement with the certified values. Finally, the developed method was successfully applied for the speciation of mercury in three environmental water samples.

  16. Speciation of mercury in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jia Xiaoyu; Han Yi; Liu Xinli [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Duan Taicheng, E-mail: tcduan@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Chen Hangting, E-mail: htchen@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China)

    2011-01-15

    The dispersive liquid-liquid microextraction (DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry for the speciation of mercury in water samples was described. Firstly methylmercury (MeHg{sup +}) and mercury (Hg{sup 2+}) were complexed with sodium diethyldithiocarbamate, and then the complexes were extracted into carbon tetrachloride by using DLLME. Under the optimized conditions, the enrichment factors of 138 and 350 for MeHg{sup +} and Hg{sup 2+} were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 0.0076 ng mL{sup -1} for MeHg{sup +} and 0.0014 ng mL{sup -1} for Hg{sup 2+}, respectively. The relative standard deviations for ten replicate measurements of 0.5 ng mL{sup -1} MeHg{sup +} and Hg{sup 2+} were 6.9% and 4.4%, respectively. Standard reference material of seawater (GBW(E)080042) was analyzed to verify the accuracy of the method and the results were in good agreement with the certified values. Finally, the developed method was successfully applied for the speciation of mercury in three environmental water samples.

  17. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Gois, Jefferson; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Welz, Bernhard [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil); Borges, Daniel L.G., E-mail: daniel.borges@ufsc.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil)

    2015-03-01

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min{sup −1}, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g{sup −1} under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample.

  18. Extraction of HCV-RNA from Plasma Samples: Development towards Semiautomation

    OpenAIRE

    Imran Amin; Tania Jabbar; Fawad Niazi; Muhammad Saeed Akhtar

    2015-01-01

    A semiautomated extraction protocol of HCV-RNA using Favorgen RNA extraction kit has been developed. The kit provided protocol was modified by replacing manual spin steps with vacuum filtration. The assay performance was evaluated by real-time qPCR based on Taqman technology. Assay linearity was confirmed with the serial dilutions of RTA (Turkey) containing 1 × (106, 105, 104, and 103) IU mL−1. Comparison of test results obtained by two extraction methods showed a good correlation (r = 0.95, ...

  19. Lipid emulsion solution: A novel cause of hemolysis in serum and plasma blood samples.

    Science.gov (United States)

    Jaben, Elizabeth A; Koch, Christopher D; Karon, Brad S

    2011-02-01

    After several hemolyzed blood samples were received in the laboratory, we investigated lipid emulsion/TPN as a novel cause of hemolysis. Whole blood was spiked with lipid emulsion and TPN. Hemolysis was proportional to the amount of lipid emulsion present in whole blood, with less hemolysis occurring in blood gas syringes compared to vacutainer tubes. Collection of specimens in blood gas syringes may prevent hemolysis in patients on lipid emulsion. Copyright © 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  20. Determination of uranium isotopic composition and {sup 236}U content of soil samples and hot particles using inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, S.F. [Radiation Physics and Chemistry Problems Inst., Minsk (Belarus); Becker, J.S. [Central Department for Analytical Chemistry, Research Centre Juelich (Germany)

    2001-07-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The {sup 236}U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10{sup -4} and 10{sup -3} counts per atom were achieved for {sup 238}U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH{sup +}/U{sup +} was 1.2 x 10{sup -4} and 1.4 x 10{sup -4}, respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 {mu}g L{sup -1} NBS U-020 standard solution was 0.11% ({sup 238}U/{sup 235}U) and 1.4% ({sup 236}U/{sup 238}U) using a MicroMist nebulizer and 0.25% ({sup 235}U/{sup 238}U) and 1.9% ({sup 236}U/{sup 238}U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the {sup 236}U/{sup 238}U ratio ranged from 10{sup -5} to 10{sup -3}. Results obtained with ICP-MS, {alpha}- and {gamma}-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples. (orig.)

  1. Ferromagnetic particles as a rapid and robust sample preparation for the absolute quantification of seven eicosanoids in human plasma by UHPLC-MS/MS.

    Science.gov (United States)

    Suhr, Anna Catharina; Bruegel, Mathias; Maier, Barbara; Holdt, Lesca Miriam; Kleinhempel, Alisa; Teupser, Daniel; Grimm, Stefanie H; Vogeser, Michael

    2016-06-01

    We used ferromagnetic particles as a novel technique to deproteinize plasma samples prior to quantitative UHPLC-MS/MS analysis of seven eicosanoids [thromboxane B2 (TXB2), prostaglandin E2 (PGE2), PGD2, 5-hydroxyeicosatetraenoic acid (5-HETE), 11-HETE, 12-HETE, arachidonic acid (AA)]. A combination of ferromagnetic particle enhanced deproteination and subsequent on-line solid phase extraction (on-line SPE) realized quick and convenient semi-automated sample preparation-in contrast to widely used manual SPE techniques which are rather laborious and therefore impede the investigation of AA metabolism in larger patient cohorts. Method evaluation was performed according to a protocol based on the EMA guideline for bioanalytical method validation, modified for endogenous compounds. Calibrators were prepared in ethanol. The calibration curves were found to be linear in a range of 0.1-80ngmL(-1) (TXB2, PGE2, PGD2), 0.05-40ngmL(-1) (5-HETE, 11-HETE), 0.5-400ngmL(-1) (12-HETE) and 25-9800ngmL(-1) (AA). Regarding all analytes and all quality controls, the resulting precision data (inter-assay 2.6 %-15.5 %; intra-assay 2.5 %-15.1 %, expressed as variation coefficient) as well as the accuracy results (inter-assay 93.3 %-125 %; intra-assay 91.7 %-114 %) were adequate. Further experiments addressing matrix effect, recovery and robustness, yielded also very satisfying results. As a proof of principle, the newly developed LC-MS/MS assay was employed to determine the capacity of AA metabolite release after whole blood stimulation in healthy blood donors. For this purpose, whole blood specimens of 5 healthy blood donors were analyzed at baseline and after a lipopolysaccharide (LPS) induced blood cell activation. In several baseline samples some eicosanoids levels were below the Lower Limit of Quantification. However, in the stimulated samples all chosen eicosanoids (except PGD2) could be quantified. These results, in context with those obtained in validation, demonstrate the

  2. Inorganic profile of some Brazilian medicinal plants obtained from ethanolic extract and ''in natura'' samples

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, M.O.M.; de Sousa, P.T.; Salvador, V.L.R.; Sato, I.M.

    2004-10-03

    The Anadenathera macrocarpa, Schinus molle, Hymenaea courbaril, Cariniana legalis, Solidago microglossa and Stryphnodendron barbatiman, were collected ''in natura'' samples (leaves, flowers, barks and seeds) from different commercial suppliers. The pharmaco-active compounds in ethanolic extracts had been made by the Mato Grosso Federal University (UFMT). The energy-dispersive x-ray fluorescence (ED-XRF) spectrometry was used for the elemental analysis in different parts of the plants and respective ethanolic extracts. The Ca, Cl, Cu, Fe, K, Mg, Mn, Na, Ni, P, Rb, S, Sr and Zn concentrations were determined by the fundamental parameters method. Some specimens showed a similar inorganic profile for ''in natura'' and ethanolic extract samples and some ones showed a distinct inorganic profile. For example, the Anadenathera macrocarpa showed a similar concentration in Mg, P, Cu, Zn and Rb elements in ''in natura'' and ethanolic extract samples; however very different concentration in Na, S, Cl, K , Ca, Mn, Fe and Sr was observed in distinctive samples. The Solidago microglossa showed the K, Ca, Cl, S, Mg, P and Fe elements as major constituents in both samples, suggesting that the extraction process did not affect in a considerable way the ''in natura'' inorganic composition. The elemental composition of the different parts of the plants (leaves, flowers, barks and seeds) has been also determined. For example, the Schinus molle specimen showed P, K, Cl and Ca elements as major constituents in the seeds, Mg, K and Sr in the barks and Mg, S, Cl and Mn in the leaves, demonstrating a differentiated elementary distribution. These inorganic profiles will contribute to evaluate the quality control of the Brazilian herbaceous trade and also will assist to identify which parts of the medicinal plants has greater therapeutic effect.

  3. Effect of residual stresses on the strength, adhesion and wear resistance of SiC coatings obtained by plasma-enhanced chemical vapor deposition on low alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Kattamis, T.Z. (Department of Metallurgy, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136 (United States)); Chen, M. (Department of Metallurgy, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136 (United States)); Skolianos, S. (Aristoteles University, Thessaloniki (Greece)); Chambers, B.V. (Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States))

    1994-11-01

    Amorphous hydrogenated silicon carbide thin coatings were deposited on AISI 4340 low alloy steel wafers and thicker steel specimens by plasma-enhanced chemical vapor deposition. The cohesion of the coating, its adhesion to the substrate and its friction coefficient were evaluated by automatic scratch testing, and its wear resistance by pin-on-disk tribometry. During annealing, the residual stress attributed to hydrogen entrapment during deposition gradually changed from compressive to tensile and its rate of increase decreased with increasing annealing time. The cohesion and adhesion failure loads and the abrasive wear resistance decreased with decreasing residual compressive stress and increasing residual tensile stress. The friction coefficient between the coating surface and a diamond stylus decreased with increasing annealing time. ((orig.))

  4. Influence of atmospheric plasma spray parameters on YSZ coatings obtained from micro and nano structured feedstocks; Influencia de los parametros de proyeccion por plasma atmosferico en recubrimientos de YSZ obtenidos a partir de polvos micro y nanoestructurados

    Energy Technology Data Exchange (ETDEWEB)

    Carpio, P.; Bannier, E.; Borrell, A.; Salvador, M. d.; Sanchez, E.

    2014-07-01

    In the present work, the influence of atmospheric plasma spray (APS) parameters on the deposition of two commercial YSZ feedstocks, one conventional and one non-conductor's, has been studied. First the study focused on how the variability of the different parameters affects the particle behaviour during spraying. For this purpose, a sensor which enables to measure the particle temperature and velocity inside the plasma was used. Once the spraying parameters influence was known, both powders were deposited by APS onto stainless steel substrates modifying the higher influencing parameters. These coatings have been characterised and the influence of the particle behaviour on the coating microstructure and properties has been analysed. This work concludes the spraying parameters variation affects on the particle velocity and temperature inside the plasma plume and this behaviour influences, in turn but in a different way, on the final coating characteristics when using different powders (micro- and nano structured). (Author)

  5. Determination of lanthanides in rock samples by inductively coupled plasma mass spectrometry using thorium as oxide and hydroxide correction standard

    Science.gov (United States)

    Raut, Narendra M.; Huang, Li-Shing; Aggarwal, Suresh K.; Lin, King-Chuen

    2003-05-01

    Determination of lanthanides by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) using modified mathematical correction method has been studied. Normally, the ICP-MS analysis of middle and heavier lanthanides becomes difficult by severe spectroscopic overlap of M +, MO + or MOH + ions from lighter lanthanides and Ba. A correction method based on a single element oxide yield measurement, is a simple approach to correct for the above spectroscopic overlaps. But the uncertainty in the oxide and hydroxide yields measurement of lanthanides and barium over a long period of time can lead to inaccurate results even under fixed plasma conditions. To correct this, thorium was adopted as an oxide and hydroxide correction standard. Using a ratio of lanthanide oxide yield to thorium oxide yield, the lanthanide correction factors (LCF) were established and incorporated in the mathematical correction scheme. The same factors were also established for hydroxide correction. The proposed modified correction scheme was applied to the determination of lanthanides by ICP-MS from the USGS Standard Rock samples AGV-1 and G-2. The results are in good agreement with the reported values. The method also proved to be useful in isotopic ratio measurement of lanthanides having severe isobaric overlaps.

  6. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples

    Science.gov (United States)

    Zheng, Lijun; Goldberg, Lewis R.; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2010-01-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject samples. The reliabilities of the five factors were quite high except for the 50-item measure of Agreeableness. The part-whole correlations between the 100-item and 50-item factors were high, as were the factor congruence coefficients between the heterosexual and the homosexual samples. Both versions of the IPIP Big-Five factor markers were strongly correlated with the scales from the Big Five Inventory (BFI: John, Donahue & Kentle, 1991), thus providing some concurrent validation in a Chinese context. PMID:20383283

  7. Obtained effect size as a function of sample size in approved antidepressants: a real-world illustration in support of better trial design.

    Science.gov (United States)

    Gibertini, Michael; Nations, Kari R; Whitaker, John A

    2012-03-01

    The high failure rate of antidepressant trials has spurred exploration of the factors that affect trial sensitivity. In the current analysis, Food and Drug Administration antidepressant drug registration trial data compiled by Turner et al. is extended to include the most recently approved antidepressants. The expanded dataset is examined to further establish the likely population effect size (ES) for monoaminergic antidepressants and to demonstrate the relationship between observed ES and sample size in trials on compounds with proven efficacy. Results indicate that the overall underlying ES for antidepressants is approximately 0.30, and that the variability in observed ES across trials is related to the sample size of the trial. The current data provide a unique real-world illustration of an often underappreciated statistical truism: that small N trials are more likely to mislead than to inform, and that by aligning sample size to the population ES, risks of both erroneously high and low effects are minimized. The results in the current study make this abstract concept concrete and will help drug developers arrive at informed gate decisions with greater confidence and fewer risks, improving the odds of success for future antidepressant trials.

  8. Synthesis and characterization of the NiFe{sub 2}O{sub 4}/Ni{sub 3}Fe nanocomposite powder and compacts obtained by mechanical milling and spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Marinca, T.F.; Neamţu, B.V.; Popa, F.; Tarţa, V.F. [Materials Sciences and Engineering Department, Technical University of Cluj-Napoca, 103-105, Muncii Avenue, 400641 Cluj-Napoca (Romania); Pascuta, P. [Physics and Chemistry Department, Technical University of Cluj-Napoca, 103-105 Muncii Avenue, 400641 Cluj-Napoca (Romania); Takacs, A.F. [Faculty of Physics, Babeş-Bolyai University, 1 Mihail Kogălniceanu, 400084 Cluj-Napoca (Romania); Chicinaş, I., E-mail: Ionel.Chicinas@stm.utcluj.ro [Materials Sciences and Engineering Department, Technical University of Cluj-Napoca, 103-105, Muncii Avenue, 400641 Cluj-Napoca (Romania)

    2013-11-15

    Nanocomposite powder and compacts of NiFe{sub 2}O{sub 4}/Ni{sub 3}Fe type were synthesized using mechanical milling and spark plasma sintering (SPS) techniques. The samples have been investigated by X-ray diffraction (XRD), laser particles size analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). The nanocomposite powder was obtained by mechanical milling in a high planetary ball mill of nanocrystalline NiFe{sub 2}O{sub 4} and nanocrystalline Ni{sub 3}Fe powders. The nanocomposite powder consists from Ni{sub 3}Fe particles covered at the surface with a layer of NiFe{sub 2}O{sub 4} fine particles and NiFe{sub 2}O{sub 4} particles. The nanocomposite particles have the median diameter d{sub 50} of 1.6 μm. The sintering in 400–600 °C temperature range preserve the nanocomposite phases but lead to a high porosity. The nanocomposite compacts consist in Ni{sub 3}Fe clusters surrounded by NiFe{sub 2}O{sub 4}. A sintering temperature of 800 °C leads to a good density for the nanocomposite compacts and to the new phase formation. The new phase is a wustite type (Fe{sub 1−x}Ni{sub x}O) and is formed at the metal/ceramic interface. A change in the Ni/Fe ratio, in the spinel structure, was evidenced during sintering. Sintering at a temperature of 800 °C, leads to the formation of a mixed iron–nickel ferrite with a very small amount of nickel, Ni{sub 1−x}Fe{sub x}Fe{sub 2}O{sub 4}.

  9. Intelligent Analysis of Samples by Semiquantitative Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) Technique: A Review.

    Science.gov (United States)

    Krzciuk, Karina

    2016-07-03

    Inductively coupled plasma-mass spectrometry (ICP-MS) is a popular and routine analytical method that has been used for determination of trace elements since the 1980s. It provides fast quantitative analysis and allows the determination of more than 70 elements with good accuracy and very low detection limits, but requires an intricate calibration procedure. In analyses of samples for which very low detection limits are not required a semiquantitative ICP-MS analysis mode can be used. This approach is more time- and cost-effective, and it uses a simple calibration procedure. This article presents a critical review of the semiquantitative (SQ) mode of ICP-MS and describes current and future applications of SQ analysis.

  10. A New Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Bisoprolol in Human Plasma Samples

    Directory of Open Access Journals (Sweden)

    Gabriela Peste

    2009-01-01

    Full Text Available Liquid chromatography (LC coupled with mass spectrometry (MS detection is one of the most powerful analytical tools for organic compound analysis. The advantages of using LC/MS methods over HPLC methods include: selectivity, chromatographic integrity, peak assignment, structural information, and rapid method development. In this paper, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS method has been developed and validated for the determination of bisoprolol in human plasma samples, using metoprolol as internal standard and liquid-liquid extraction procedure. The assay has proven to be sensitive, specific and reproducible, suitable to determine the bisoprolol concentration, following a single oral administration of a 10 mg bisoprolol tablet in 22 healthy volunteers, in the bioequivalence study of Bisoprolol 10 mg coated tablets, produced by Antibiotice S.A. versus Concor 10 mg, produced by Merck.

  11. Simultaneous derivatization and solid-based disperser liquid-liquid microextraction for extraction and preconcentration of some antidepressants and an antiarrhythmic agent in urine and plasma samples followed by GC-FID.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Khorram, Parisa; Ghorbanpour, Houshang

    2015-03-01

    The present work is based on a one-step method including derivatization and solid-based disperser liquid-liquid microextraction followed by gas chromatography-flame ionization detection (GC-FID) for the determination of four antidepressants (fluoxetine, fluvoxamine, tranylcypromine, and nortriptyline) and an antiarrhythmic agent (mexiletine) in human urine and plasma samples. In this method, a mixture of 1,1,2,2-tetrachloroethane (extraction solvent) and butylchloroformate (derivatizing reagent) is added on a sugar cube (solid disperser) and it is introduced into an aqueous sample containing the analytes and a catalyst, e.g. 3-methylpyridine (picoline). During dissolving the sugar cube by manual shaking, the extractant and derivatization agent are gradually released into the sample as very fine droplets. Then the resulted cloudy solution is centrifuged and the sedimented phase is analyzed by GC-FID. The influence of several variables on the efficiency of derivatization/microextraction procedure such as kind and volume of extraction solvent, type and amount of disperser, amount of derivatization agent, and catalyst volume are optimized. Under the optimum conditions the calibration curves are linear in the range of 8-100,000μgL(-1) (coefficient of determination ≥0.994). The relative standard deviations are obtained in the range of 3.0-6.0% for all compounds. Moreover, the detection limits and enrichment factors of the target analytes are obtained in the ranges 1-15μgL(-1) and 228-268, respectively, for both plasma and urine samples. The relative recoveries obtained for the spiked plasma and urine samples are between 70 and 91%. The results show that the proposed method is simple, reliable, low cost, and applicable to determine trace amounts of the studied drugs in biological samples.

  12. Prevalence of human papillomavirus in archival samples obtained from patients with cervical pre-malignant and malignant lesions from Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Prado José CM

    2010-04-01

    Full Text Available Abstract Background Human Papillomavirus (HPV is considered as a necessary, but not sufficient, cause of cervical cancer. In this study, we aimed to assess the prevalence of HPV in a series of pre-malignant and malignant cervical lesion cases, to identify the virus genotypes, and to assess their distribution pattern according to lesion type, age range, and other considered variables. The samples were submitted to histopathological revision examination and analysed by polymerase chain reaction (PCR for the presence of HPV DNA, followed by HPV typing by dot blot hybridisation. Findings Of the analysed samples, 53.7% showed pre-malignant cervical lesions, and 46.3% presented with cervical cancer. Most cancer samples (84.1% were classified as invasive carcinoma. The mean age of these cancer patients was 47.3 years. The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cancer patients. HPV 16 was the most prevalent type, followed by HPV 18 and 58, including both single and double infections. Double infection was detected in 11.6% of the samples, and the most common combination was HPV 16+18. Conclusions Cervical cancer appears to occur in women in a lower age range in the studied area, compared to the situation in other Brazilian regions. Furthermore, among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts. Findings The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cervical cancer patients from Northeast Brazil. HPV 16 was the most prevalent type, followed by HPV 18 and 58. The most common double infection was HPV 16+18. Cervical cancer appears to occur in women in a lower age range in the Northeast Brazil. Among the patients with CIN 3 and those with cancer, we observed a higher

  13. Analysis of DDT and its metabolites in soil and water samples obtained in the vicinity of a closed-down factory in Bangladesh using various extraction methods.

    Science.gov (United States)

    Al Mahmud, M N U; Khalil, Farzana; Rahman, Md Musfiqur; Mamun, M I R; Shoeb, Mohammad; Abd El-Aty, A M; Park, Jong-Hyouk; Shin, Ho-Chul; Nahar, Nilufar; Shim, Jae-Han

    2015-12-01

    This study was conducted to monitor the spread of dichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD)) in soil and water to regions surrounding a closed DDT factory in Bangladesh. This fulfillment was accomplished using inter-method and inter-laboratory validation studies. DDTs (DDT and its metabolites) from soil samples were extracted using microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), and solvent extraction (SE). Inter-laboratory calibration was assessed by SE, and all methods were validated by intra- and inter-day accuracy (expressed as recovery %) and precision (expressed as relative standard deviation (RSD)) in the same laboratory, at three fortified concentrations (n = 4). DDTs extracted from water samples by liquid-liquid partitioning and all samples were analyzed by gas chromatography (GC)-electron capture detector (ECD) and confirmed by GC/mass spectrometry (GC/MS). Linearities expressed as determination coefficients (R (2)) were ≥0.995 for matrix-matched calibrations. The recovery rate was in the range of 72-120 and 83-110%, with <15% RSD in soil and water, respectively. The limit of quantification (LOQ) was 0.0165 mg kg(-1) in soil and 0.132 μg L(-1) in water. Greater quantities of DDTs were extracted from soil using the MAE and SE techniques than with the SFE method. Higher amounts of DDTs were discovered in the southern (2.2-936 × 10(2) mg kg(-1)) or southwestern (86.3-2067 × 10(2) mg kg(-1)) direction from the factory than in the eastern direction (1.0-48.6 × 10(2) mg kg(-1)). An exception was the soil sample collected 50 ft (15.24 m) east (2904 × 10(2) mg kg(-1)) of the factory. The spread of DDTs in the water bodies (0.59-3.01 μg L(-1)) was approximately equal in all directions. We concluded that DDTs might have been dumped randomly around the warehouse after the closing of the factory.

  14. Plasma, blood and liver tissue sample preparation methods for the separate quantification of liposomal-encapsulated prednisolone phosphate and non-encapsulated prednisolone

    NARCIS (Netherlands)

    Smits, Evelien A W; Soetekouw, José A; Bakker, Peter F A; Baijens, Bart J H; Vromans, Herman

    2015-01-01

    Besides the development of sample preparation methods for the determination of separate liposomal-encapsulated prednisolone phosphate and non-encapsulated prednisolone concentrations in murine plasma and blood, this article also presents the first description of an accurate sample preparation method

  15. Polybrominated diphenyl ethers in paired samples of maternal and umbilical cord blood plasma and associations with house dust in a Danish cohort

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Thomsen, Cathrine; Frøshaug, May

    2010-01-01

    . The sum of tri- to hexa-BDEs (SigmaPBDE) in maternal plasma varied between 640 and 51,946pg/g lipid weight (lw) with a median level of 1765pg/g lw. In the umbilical cord samples SigmaPBDE varied between 213 and 54,346pg/g lw with a median of 958pg/g lw. The levels observed in fetal and maternal plasma...... individuals. Furthermore, positive correlations (pSigmaPBDE in maternal plasma and house dust as well as for SigmaPBDE in umbilical cord plasma and house dust. The positive correlations for PBDEs for both maternal and umbilical cord plasma with house dust showed...

  16. Problems, possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum, palladium and rhodium in samples with different matrix composition

    Science.gov (United States)

    Petrova, P.; Velichkov, S.; Velitchkova, N.; Havezov, I.; Daskalova, N.

    2010-02-01

    The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g - 1 were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts. The accuracy of the analytical results was experimentally demonstrated by two certified reference materials that were analyzed: SARM 7, Pt ore and recycled auto-catalyst certified reference material SRM 2556.

  17. Problems, possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum, palladium and rhodium in samples with different matrix composition

    Energy Technology Data Exchange (ETDEWEB)

    Petrova, P.; Velichkov, S. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria); Velitchkova, N. [Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., bl.24, 1113 Sofia (Bulgaria); Havezov, I. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria); Daskalova, N., E-mail: das15482@svr.igic.bas.b [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria)

    2010-02-15

    The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g{sup -1} were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts. The accuracy of the analytical results was experimentally demonstrated by two certified reference materials that were analyzed: SARM 7, Pt ore and recycled auto-catalyst certified reference material SRM 2556.

  18. The determination of trace element concentrations in fly ash samples using ultrasound-assisted digestion followed with inductively coupled plasma optical emission spectrometry

    OpenAIRE

    Ilander, Aki; Väisänen, Ari

    2009-01-01

    A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element (chromium, copper, lead, nickel, vanadium and zinc) concentrations in fly ash samples was developed. All the measurements were performed in robust plasma conditions. Ultrasound-assisted digestion procedures using digestion solutions of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 80% for all the analyte...

  19. An ultrasound-assisted digestion method for the determination of toxic element concentrations in ash samples by inductively coupled plasma optical emission spectrometry

    OpenAIRE

    Ilander, Aki; Väisänen, Ari

    2007-01-01

    method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of toxic element concentrations (arsenic, barium, cobalt, copper, lead, nickel, strontium, vanadium and zinc) in ash samples was developed. All the measurements were performed in robust plasma conditions which were tested by measuring the Mg(II) 280.270 nm/Mg(I) 285.213 nm line intensity ratios. The highest line intensity ratios were observed when a...

  20. Determination of Se in biological samples by axial view inductively coupled plasma optical emission spectrometry after digestion with aqua regia and on-line chemical vapor generation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Eder Jose dos [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil)], E-mail: eder@tecpar.br; Herrmann, Amanda Beatriz; Kulik de Caires, Suzete [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil); Azzolin Frescura, Vera Lucia; Curtius, Adilson Jose [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), 880400-900 Florianopolis, SC (Brazil)

    2009-06-15

    A simple and fast method for the determination of Se in biological samples, including food, by axial view inductively coupled plasma optical emission spectrometry using on-line chemical vapor generation (CVG-ICP OES) is proposed. The concentrations of HCl and NaBH{sub 4}, used in the chemical vapor generation were optimized by factorial analysis. Six certified materials (non-fat milk powder, lobster hepatopancreas, human hair, whole egg powder, oyster tissue, and lyophilised pig kidney) were treated with 10 mL of aqua regia in a microwave system under reflux for 15 min followed by additional 15 min in an ultrasonic bath. The solutions were transferred to a 100 mL volumetric flask and the final volume was made up with water. The Se was determined directly in these solutions by CVG-ICP OES, using the analytical line at 196.026 nm. Calibration against aqueous standards in 10% v/v aqua regia in the concentration range of 0.5-10.0 {mu}g L{sup -} {sup 1} Se(IV) was used for the analysis. The quantification limit, considering a 0.5 g sample weight in a final volume of 100 mL{sup -} {sup 1} was 0.10 {mu}g g{sup -} {sup 1}. The obtained concentration values were in agreement with the total certified concentrations, according to the t-test for a 95% confidence level.

  1. Slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry for the direct determination of metal impurities in aluminium oxide ceramic powders.

    Science.gov (United States)

    Peng, T; Chang, G; Wang, L; Jiang, Z; Hu, B

    2001-03-01

    A new analytical procedure for the direct determination of metal impurities (Cr, Cu, Fe and V) in aluminium oxide ceramic powders by slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) is reported. A polytetrafluoroethylene (PTFE) emulsion was used as a fluorinating reagent to promote the vaporization of impurity elements in aluminium oxide ceramic powders from the graphite tube. A vaporization stage with a long ramp time and a short hold time provided the possibility of temporal analyte-matrix separation. The experimental results indicated that a 10 microL 1% m/v slurry of aluminium oxide could be destroyed and vaporized completely with 600 micrograms PTFE under the selected conditions. Two aluminium oxide ceramic powder samples were used without any additional pretreatment. Analytical results obtained by using standard addition method with aqueous standard solution were checked by comparison of the results with pneumatic nebulization (PN)-ICP-AES based on the wet-chemical decomposition and analyte-matrix separation. The limits of detection (LODs) between 0.30 microgram g-1 (Fe) and 0.08 microgram g-1 (Cu) were achieved, and, the repeatability of measurements was mainly better than 10%.

  2. Simultaneous extraction and preconcentration of uranium and thorium in aqueous samples by new modified mesoporous silica prior to inductively coupled plasma optical emission spectrometry determination.

    Science.gov (United States)

    Yousefi, Seyed Reza; Ahmadi, Seyed Javad; Shemirani, Farzaneh; Jamali, Mohammad Reza; Salavati-Niasari, Masoud

    2009-11-15

    A new synthesized modified mesoporous silica (MCM-41) using 5-nitro-2-furaldehyde (fural) was applied as an effective sorbent for the solid phase extraction of uranium(VI) and thorium(IV) ions from aqueous solution for the measurement by inductively coupled plasma optical emission spectrometry (ICP OES). The influences of some analytical parameters on the quantitative recoveries of the analyte ions were investigated in batch method. Under optimal conditions, the analyte ions were sorbed by the sorbent at pH 5.5 and then eluted with 1.0 mL of 1.0 mol L(-1) HNO(3). The preconcentration factor was 100 for a 100mL sample volume. The limits of detection (LOD) obtained for uranium(VI) and thorium(IV) were 0.3 microg L(-1). The maximum sorption capacity of the modified MCM-41 was found to be 47 and 49 mg g(-1) for uranium(VI) and thorium(IV), respectively. The sorbent exhibited good stability, reusability, high adsorption capacity and fast rate of equilibrium for sorption/desorption of uranium and thorium ions. The applicability of the synthesized sorbent was examined using CRM and real water samples.

  3. Characterization of extended-spectrum β-lactamase (ESBL)-producing Klebsiella, Enterobacter, and Citrobacter obtained in environmental samples of a Tunisian hospital.

    Science.gov (United States)

    Dziri, Raoudha; Klibi, Naouel; Alonso, Carla Andrea; Said, Leila Ben; Bellaaj, Ridha; Slama, Karim Ben; Boudabous, Abdellatif; Torres, Carmen

    2016-10-01

    The assessment of the hospital environment as a reservoir of ESBL-producing Enterobacteriaceae in Tunisian hospitals is scarcely analyzed, except for Escherichia coli. The aim of this study was to evaluate the presence of ESBL-producing non-E. coli Enterobacteriaceae (ESBL-EbNoEc) in 300 samples of abiotic surfaces and the hands of patients and staff of a Tunisian Hospital, and to characterize the ESBL genes of the recovered isolates. ESBL-EbNoEc were recovered in 28 of 300 (9.3%) analyzed samples and were identified as Klebsiella pneumoniae (n= 11), Enterobacter cloacae (n=11), Citrobacter freundii (n=4) and Klebsiella oxytoca (n=2). The bla genes identified by PCR and sequencing among the strains were as follows: 11 K.pneumoniae strains [blaCTX-M-15+ blaTEM-1+ blaSHV-11 (n=6); blaCTX-M-15+ blaTEM-1+ blaSHV-28 (n=3); blaCTX-M-15+ blaTEM-1+ blaSHV-1 (n=2)], 11 E. cloacae strains [blaCTX-M-15 (n=6); blaCTX-M-15+ blaTEM-1b (n=2); blaCTX-M-15+ blaTEM-1b+ blaOXA-1 (n=1);blaCTX-M-15+ blaOXA-1 (n=1);blaSHV-12 (n=1)], 4 C. freundii strains [blaCTX-M-15] and 2 K. oxytoca strains [blaCTX-M-15 (n=1); blaSHV-12 (n=1)]. The ISEcp1 and orf477 sequences were identified upstream and downstream of the blaCTX-M-15 gene, respectively, in 3 K. pneumoniae and 3 E. cloacae isolates. The PFGE analysis demonstrated three unrelated pulsotypes in K. pneumoniae strains and five pulsotypes in E. cloacae. The uncontrolled dissemination of ESBL-producing bacteria, even in the hospital environment, has become a real problem and new strategies and hygienic rules are needed to stop this bacterial dissemination.

  4. DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.

    2010-07-26

    A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

  5. Determination of metformin in mouse, rat, dog and human plasma samples by laser diode thermal desorption/atmospheric pressure chemical ionization tandem mass spectrometry.

    Science.gov (United States)

    Swales, John G; Gallagher, Richard; Peter, Raimund M

    2010-11-02

    A simple, rapid and robust high-throughput assay for the quantitative analysis of metformin in plasma from different species using laser diode thermal desorption interfaced with atmospheric chemical pressure ionization tandem mass spectrometry (LDTD-APCI-MSMS) was developed for use in a pharmaceutical discovery environment. In order to minimize sample preparation a generic protein precipitation method was used to extract metformin from the plasma. Laser diode thermal desorption is a relatively new sample introduction method, the optimization of the instrumental parameters are presented. The method was successfully applied to spiked mouse, rat, dog and human plasma samples and was subsequently used to determine the oral pharmacokinetics of metformin after dosing to male rats in order to support drug discovery projects. The deviations for intra-assay accuracy and precision across the four species were less than 30% at all calibration and quality control levels.

  6. A rapid, accurate and robust particle-based assay for the simultaneous screening of plasma samples for the presence of five different anti-cytokine autoantibodies

    DEFF Research Database (Denmark)

    Guldager, Daniel Kring Rasmussen; von Stemann, Jakob Hjorth; Larsen, Rune

    2015-01-01

    PURPOSE: To establish and validate a rapid, cost-effective and accurate screening assay for the simultaneous testing of human naturally occurring anti-cytokine autoantibodies (c-aAb) targeting interleukin-1α (IL-1α), interleukin-6 (IL-6), interleukin-10 (IL-10), granulocyte-macrophage colony...... plasma samples and pooled normal immunoglobulin preparations were used to validate the assay. Plasma samples from 98 transfusion recipients, half of whom presented with febrile reactions, were tested by the assay. RESULTS: The assay detected specific and saturable immunoglobulin G (IgG) binding to each...... cytokine autoantibodies quantities in the negative plasma samples ranged between 80% and 125%. The analytical intra- and inter-assay variations were 4% and 11%, respectively. Varying c-aAb levels were detectable in the transfusion recipients. There was no difference in c-aAb frequency between the patients...

  7. Speciation of gadolinium in surface water samples and plants by hydrophilic interaction chromatography hyphenated with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lindner, Uwe; Lingott, Jana; Richter, Silke; Jakubowski, Norbert; Panne, Ulrich

    2013-02-01

    Hydrophilic interaction chromatography (HILIC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was optimized for speciation analysis of gadolinium-based contrast agents in environmental samples, in particular surface river waters and plants. Surface water samples from the Teltow channel, near Berlin, were investigated over a distance of 5 km downstream from the influx of a wastewater treatment plant. The total concentration of gadolinium increased significantly from 50 to 990 ng L(-1) due to the influx of the contrast agents. After complete mixing with the river water, the concentration remained constant over a distance of at least 4 km. Two main substances [Dotarem(®) (Gd-DOTA) and Gadovist(®) (Gd-BT-DO3A)] have been identified in the river water using standards. A gadolinium-based contrast agent, possibly Gd-DOTA (Dotarem(®)), was also detected in water plant samples taken from the Teltow channel. Therefore, uptake of contrast agents [Gadovist(®) (Gd-BTDO3A), Magnevist(®) (Gd-DTPA), Omniscan(®) (Gd-DTPA-BMA), Dotarem(®) (Gd-DOTA), and Multihance(®) (Gd-BOPTA)] by plants was investigated in a model experiment using Lepidium sativum (cress plants). HILIC-ICP-MS was used for identification of different contrast agents, and a first approach for quantification using aqueous standard solutions was tested. For speciation analysis, all investigated contrast agents could be extracted from the plant tissues with a recovery of about 54 % for Multihance(®) (Gd-BOPTA) up to 106 % for Gadovist(®) (Gd-BT-DO3A). These experiments demonstrate that all contrast agents investigated are transported from the roots to the leaves where the highest content was measured.

  8. Pharmacokinetics of tulathromycin in plasma and milk samples after a single subcutaneous injection in lactating goats (Capra hircus).

    Science.gov (United States)

    Grismer, B; Rowe, J D; Carlson, J; Wetzlich, S E; Tell, L A

    2014-04-01

    Eight adult female dairy goats received one subcutaneous administration of tulathromycin at a dosage of 2.5 mg/kg body weight. Blood and milk samples were assayed for tulathromycin and the common fragment of tulathromycin, respectively, using liquid chromatography/mass spectrometry. Pharmacokinetic disposition of tulathromycin was analyzed by a noncompartmental approach. Mean plasma pharmacokinetic parameters (±SD) following single-dose administration of tulathromycin were as follows: C(max) (121.54 ± 19.01 ng/mL); T(max) (12 ± 12-24 h); area under the curve AUC(0→∞) (8324.54 ± 1706.56 ng·h/mL); terminal-phase rate constant λz (0.01 ± 0.002 h⁻¹); and terminal-phase rate constant half-life t1/2λz (67.20 h; harmonic). Mean milk pharmacokinetic parameters (±SD) following 45 days of sampling were as follows: Cmax (1594 ± 379.23 ng/mL); Tmax (12 ± 12-36 h); AUC(0→∞) (72,250.51 ± 18,909.57 ng·h/mL); λz (0.005 ± 0.001 h⁻¹); and t(1/2λz) (155.28 h; harmonic). All goats had injection-site reactions that diminished in size over time. The conclusions from this study were that tulathromycin residues are detectable in milk samples from adult goats for at least 45 days following subcutaneous administration, this therapeutic option should be reserved for cases where other treatment options have failed, and goat milk should be withheld from the human food chain for at least 45 days following tulathromycin administration.

  9. Acoustic emission study on flexural behaviour of WC-Co coatings obtained by atmospheric plasma spray; Estudio por emision acustica del comportamiento a flexion de recubrimientos WC-Co obtenidos por plasma atomosferico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, F.; Klyatskina, E.; Bonache, V.; Salvador, M. D.; Sanchez, E.; Cantavella, V.; Bloem, C.

    2007-07-01

    Plasma spayed cermet coatings WC-Co are used in a wide range of industrial applications, mainly due to their wear resistance even in corrosive environments. the objective of this work is to analyze mechanical response of hard metal coatings by means of three-and four-points bend tests applying acoustic emission technique to determine failure critical strength. It has been observed the effect of supported charge level in structural damage by means of optical microscopy and scanning electron microscopy. Acoustic emission has allowed us to relate damage level to stresses level and then to understand coatings failure mechanism. (Author) 29 refs.

  10. An efficient sample preparation method for high-throughput analysis of 15(S)-8-iso-PGF2α in plasma and urine by enzyme immunoassay.

    Science.gov (United States)

    Bielecki, A; Saravanabhavan, G; Blais, E; Vincent, R; Kumarathasan, P

    2012-01-01

    Although several methods have been reported on the analysis of the oxidative stress marker 15(S)-8-iso-prostaglandin-F2alpha (8-iso-PGF2α) in biological fluids, they either involve extensive sample preparation and costly technology or require high sample volume. This study presents a sample preparation method that utilizes low sample volume for 8-iso-PGF2α analysis in plasma and urine by an enzyme immunoassay (EIA). In brief, 8-iso-PGF2α in deproteinized plasma or native urine sample is complexed with an antibody and then captured by molecular weight cut-off filtration. This method was compared with two other sample preparation methods that are typically used in the analysis of 8-iso-PGF2α by EIA: Cayman's affinity column purification method and solid-phase extraction on C-18. The immunoaffinity purification method described here was superior to the other two sample preparation methods and yielded recovery values of 99.8 and 54.1% for 8-iso-PGF2α in plasma and urine, respectively. Analytical precision (relative standard deviation) was ±5% for plasma and ±15% for urine. The analysis of healthy human plasma and urine resulted in basal 8-iso-PGF2α levels of 31.8 ± 5.5 pg/mL and 2.9 ± 2.0 ng/mg creatinine, respectively. The robustness and analytical performance of this method makes it a promising tool for high-throughput screening of biological samples for 8-iso-PGF2α.

  11. Characterization and application of restricted access carbon nanotubes in online extraction of anticonvulsant drugs from plasma samples followed by liquid chromatography analysis.

    Science.gov (United States)

    Dos Santos, Rodrigo Campos; Kakazu, Adriana Kaori; Santos, Mariane Gonçalves; Belinelli Silva, Fábio Antônio; Figueiredo, Eduardo Costa

    2017-06-01

    Anticonvulsant drugs are often used in the treatment of epilepsy. However, their therapeutic monitoring is often necessary in order to obtain an appropriate dose adjustment, due to the proximity between their therapeutic and toxic ranges. The aim of this study was to carry out the synthesis, characterization and use of restricted access carbon nanotubes (RACNTs) in an online method for the analyses of phenobarbital and carbamazepine and primidone from untreated human blood plasma by column switching liquid chromatography. Therefore, the synthesis of RACNTs was carried out through coating commercial Carbon nanotubes with bovine serum albumin (BSA) to subsequently use them as adsorbents in a column switching system operating in the backflush mode. This material was evaluated through the construction of the kinetic and isotherm curves. The experimental data for the interaction of primidone with RACNTs were adequately adjusted to the chemisorption and Sips models for the kinetic and adsorption studies, respectively. The analytical curves ranged from 2.0 to 40.0mgL(-1), with correlation coefficients higher than 0.99, for all the analytes. The LODs of 0.1, 0.1 and 0.01μgmL(-1) were defined for PHB, PRM and CBZ, respectively. The relative standard deviation values ranged from 1.0% to 8.4% for the intra assay precision and from 2.7% to 7.6% for inter assay precision. The relative error values ranged from -13.4% to 7.7% for the intra assay accuracy and from -8.6% to 2.5% for the inter assay accuracy. The method was adequately used in the therapeutic monitoring of anticonvulsant drugs in human plasma samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Pharmacokinetics of dilevalol and its conjugates in man. Assay method for plasma, blood, urine and bile samples and preliminary pharmacokinetic studies.

    Science.gov (United States)

    Neubeck, M; Becker, C; Henke, D; Rösch, W; Spahn-Langguth, H; Mutschler, E

    1993-09-01

    The renal and biliary excretion of the beta-adrenoceptor blocking agent dilevalol (CAS 75659-07-3) and its conjugates was examined in a preliminary pharmacokinetic study. Plasma, urine and bile dilevalol concentrations were determined with a simplified procedure that is based on alkaline liquid-liquid extraction using diethyl ether and subsequent reversed-phase HPLC separation of the reconstituted samples (on a PRP-1 stationary phase using a mixture of methanol and pH 9.8 carbonate buffer as mobile phase). Triamterene was used as internal standard. The quantification of the conjugates was accomplished indirectly via enzymatic hydrolysis (glusulase) with and without addition of the beta-glucuronidase inhibitor 1,4-saccharolactone (at a final concentration of 5.5 mmol/l). In the pharmacokinetic study healthy volunteers and cholecystectomised patients with a T-drain received a single oral dose of 200 mg dilevalol. Furthermore, to healthy volunteers an i.v. dose of 60 mg dilevalol was given in order to estimate the absolute bioavailability. From the obtained data the systemic plasma clearance was calculated to be 1708 ml/min. The oral bioavailability was calculated to be 16%. The log concentration-time curves of the metabolites paralleled those of dilevalol in the terminal section with average terminal half-lives of approx. 5 h. In volunteers the fractions of the dose excreted renally were 0.5% for parent drug, 23% for the glucuronide(s) and 8% for the sulfate. The corresponding values found for the patients were not significantly different. In the patients' bile only 1.2% of the total dose were found (0.03% dilevalol, 1.1% dilevalol glucuronide(s), 0.1% dilevalol sulfate).(ABSTRACT TRUNCATED AT 250 WORDS)

  13. plasma treatment

    Directory of Open Access Journals (Sweden)

    Puač Nevena

    2014-11-01

    Full Text Available In this paper we will present results for plasma sterilization of planktonic samples of two reference strains of bacteria, Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. We have used a plasma needle as a source of non-equilibrium atmospheric plasma in all treatments. This device is already well characterized by OES, derivative probes and mass spectrometry. It was shown that power delivered to the plasma is bellow 2 W and that it produces the main radical oxygen and nitrogen species believed to be responsible for the sterilization process. Here we will only present results obtained by electron paramagnetic resonance which was used to detect the OH, H and NO species. Treatment time and power delivered to the plasma were found to have the strongest influence on sterilization. In all cases we have observed a reduction of several orders of magnitude in the concentration of bacteria and for the longest treatment time complete eradication. A more efficient sterilization was achieved in the case of gram negative bacteria.

  14. Multistage plasma initiation process by pulsed CO2 laser irradiation of a Ti sample in an ambient gas (He, Ar, or N2)

    Science.gov (United States)

    Hermann, J.; Boulmer-Leborgne, C.; Mihailescu, I. N.; Dubreuil, B.

    1993-02-01

    New experimental results are reported on plasma initiation in front of a titanium sample irradiated by ir (λ=10.6 μm) laser pulses in an ambient gas (He, Ar, and N2) at pressures ranging from several Torr up to the atmosphere. The plasma is studied by space- and time-resolved emission spectroscopy, while sample vaporization is probed by laser-induced fluorescence spectroscopy. Threshold laser intensities leading to the formation of a plasma in the vapor and in the ambient gases are determined. Experimental results support the model of a vaporization mechanism for the plasma initiation (vaporization-initiated plasma breakdown). The plasma initiation is described by simple numerical criteria based on a two-stage process. Theoretical predictions are found to be in a reasonable agreement with the experiment. This study provides also a clear explanation of the influence of the ambient gas on the laser beam-metal surface energy transfer. Laser irradiation always causes an important vaporization when performed in He, while in the case of Ar or N2, the interaction is reduced in heating and vaporization of some surface defects and impurities.

  15. A simple and practical control of the authenticity of organic sugarcane samples based on the use of machine-learning algorithms and trace elements determination by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Barbosa, Rommel M; Batista, Bruno L; Barião, Camila V; Varrique, Renan M; Coelho, Vinicius A; Campiglia, Andres D; Barbosa, Fernando

    2015-10-01

    A practical and easy control of the authenticity of organic sugarcane samples based on the use of machine-learning algorithms and trace elements determination by inductively coupled plasma mass spectrometry is proposed. Reference ranges for 32 chemical elements in 22 samples of sugarcane (13 organic and 9 non organic) were established and then two algorithms, Naive Bayes (NB) and Random Forest (RF), were evaluated to classify the samples. Accurate results (>90%) were obtained when using all variables (i.e., 32 elements). However, accuracy was improved (95.4% for NB) when only eight minerals (Rb, U, Al, Sr, Dy, Nb, Ta, Mo), chosen by a feature selection algorithm, were employed. Thus, the use of a fingerprint based on trace element levels associated with classification machine learning algorithms may be used as a simple alternative for authenticity evaluation of organic sugarcane samples.

  16. Solvent bar microextraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry for the speciation of inorganic arsenic in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Pu Xuli; Chen Beibei [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Hu Bin [Department of Chemistry, Wuhan University, Wuhan 430072 (China)], E-mail: binhu@whu.edu.cn

    2009-07-15

    A new method of solvent bar microextraction (SBME) combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the speciation of As(III) and As(V) in water samples was developed. The method is based on the chelation of As(III) and ammonium pyrrolidine dithiocarbamate (APDC) under the selected conditions, and the As(III)-PDC complex could be extracted into the organic phase, while As(V) remained in aqueous solution. The post-extraction organic phase was directly injected into ETV-ICP-MS for determination of As(III) with the use of iridium as permanent chemical modifier. As(V) was reduced to As(III) by L-cysteine and was then subjected to SBME prior to total As determination. The assay of As(V) was based on subtracting As(III) from total As. The factors affecting on the SBME, such as organic solvent, sample pH, chelating reagent concentration, stirring rate and extraction time, and chemical modification of iridium in ETV-ICP-MS have been studied. Under the optimized conditions, the enrichment factor of 220-fold could be achieved in 15 min extraction, the limit of detection (LOD) for As(III) was 0.32 pg mL{sup - 1}, and the relative standard deviation (RSD) was 8.8% (0.1 ng mL{sup - 1}, n = 9). Compared with hollow fiber liquid phase microextraction (HF-LPME), SBME has a higher enrichment factor and faster extraction kinetics. In order to validate the accuracy of the method, a Certified Reference Material of GSBZ50004-88 (No. 200420) water sample was analyzed and the results obtained were in good agreement with the certified values. The developed method was also applied to the speciation of inorganic As in environmental waters with satisfactory results.

  17. Rapid Changes in Circulating Tumor DNA in Serially Sampled Plasma During Treatment of Breast Cancer: A Case Report

    Science.gov (United States)

    Nakagomi, Hiroshi; Hirotsu, Yosuke; Amemiya, Kenji; Nakada, Haruka; Inoue, Masayuki; Mochizuki, Hitoshi; Oyama, Toshio; Omata, Masao

    2017-01-01

    Patient: Female, 45 Final Diagnosis: Breast cancer Symptoms: Breast tumor Medication: — Clinical Procedure: Analysis of circulating tumor DNA Specialty: Oncology Objective: Unusual setting of medical care Background: The analysis of circulating tumor DNA (ctDNA) is expected to be a modality to determine the status of cancer in real time. This case indicated utilities and issues in measuring the ctDNA in cancer patients. Case Report: A 45-year-old woman with metastatic breast cancer was treated with bevacizumab and paclitaxel. The lung metastases were decreased but the meningitis carcinoma developed rapidly and she died. During the treatment with bevacizumab and paclitaxel, blood samples were taken serially and ctDNA was analyzed using a next-generation sequencer. TP53 frameshift mutation (TP53; p.Arg158fs with 7 nucleotides deletion) was identified in the tumor, and dynamic change in this mutation in ctDNA was observed in serially sampled plasma in this patient. We observed a rapid decrease of TP53 mutation at the beginning of treatment, then it increased as a sign of relapse. However, the high allelic fraction value of TP53 mutation was not consistent during the progression of cancer, suggesting that several factors affected the value of ctDNA. Conclusions: Although this is a single-case experience, it strongly suggests ctDNA could be a modality to determine the cancer status in real time. However, we found that several factors affected the value of ctDNA. Further investigations are needed to reveal the significance of these very high-sensitivity changes. PMID:28065930

  18. UPLC-MS/MS assay of riluzole in human plasma and cerebrospinal fluid (CSF): Application in samples from spinal cord injured patients.

    Science.gov (United States)

    Sarkar, Mahua; Grossman, Robert G; Toups, Elizabeth G; Chow, Diana S-L

    2017-09-01

    In the present study, a sensitive and robust LC-MS/MS method has been developed and validated for the quantification of riluzole in human plasma and cerebrospinal fluid (CSF) in clinical samples from patients with spinal cord injury (SCI). Riluzole and its labeled internal standard (IS) were isolated from plasma and CSF by liquid-liquid extraction using ethyl acetate. Riluzole (m/z 235→166) and IS (m/z 238→169) were detected by electrospray ionization (ESI) using multiple reaction monitoring (MRM) in a positive mode. The assay was linear in the concentration range of 0.5 (LLOQ, signal/noise ratio>10)-800ng/ml in plasma, and 1.0 (LLOQ)-800ng/ml in CSF samples. The intra- and inter-day accuracy in plasma were 94.2-110.0% and 97.8-102.0%, respectively, and those in CSF were 87.6-105.1% and 91.9-98.8%, respectively. The intra- and inter-day precision were 2.2-7.2% and 4.0-9.1%, respectively, in plasma, and 1.4-14.1% and 2.6-11.5%, respectively in CSF. Matrix effect was negligible from both matrices with signal percentages of 97.6-100.6% in plasma and 99.4-106.4% in CSF. The recoveries were >75% in plasma, >84% in CSF with low protein (53.9mg/dl), and >68% in CSF with high protein (348.2mg/dl). This method was successfully applied to quantify riluzole concentrations in plasma and CSF from patients with SCI. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A novel aeration-assisted homogenous liquid-liquid microextration for determination of thorium and uranium in water and hair samples by inductively coupled plasma-mass spectroscopy.

    Science.gov (United States)

    Veyseh, Somayeh; Niazi, Ali

    2016-01-15

    A novel method based on aeration-assisted homogeneous liquid-liquid microextraction using high density solvent is presented, which is combined with inductively coupled plasma-mass spectroscopy in which simultaneous preconcentration and determination of thorium and uranium with arsenazo III as the chelating reagent is carried out. To achieve optimum conditions, several parameters such as pH, concentration of arsenazo III, extraction and homogenous solvent types and their volumes, salt concentration and extraction time were investigated. Under which, the calibration graphs were linear in the range of 0.5-600.0ng L(-1) for thorium and 0.3-550.0ng L(-1) for uranium. Good linearities were obtained for both analytes with R(2) values larger than 0.9990. The limits of detection (LOD, 3Sb/m, n=5) of this method were 0.12 and 0.09ng L(-1), and the enrichment factors were estimated to be 370 and 410 for thorium and uranium, respectively. The proposed method was applied to determine the thorium and uranium in human hair and different environmental water samples. Acceptable recoveries ranged from 99.4% to 100.7% with standard deviation of 0.05 to 0.17.

  20. Radiochemical Separation and Measurement by Mass Spectrometry with Magnetic Sector with Inductively Coupled Plasma source (ICP-SFMS of Plutonium Isotopes in Soil Samples

    Directory of Open Access Journals (Sweden)

    C. O. Torres-Cortés

    2016-08-01

    Full Text Available The aim of this work is twofold: to optimize the radiochemical separation of Plutonium (Pu from soil samples, and to measure the Pu concentration. Soil samples were prepared using acid digestion assisted by microwaves; then, Pu purification was carried out with Pu AG1X8 resin. Pu isotopes were measured using Mass Spectrometry with Magnetic Sector with Inductively Coupled Plasma source (ICP-SFMS. In order to reduce the interference due to the presence of 238UH+ in the samples a desolvation system (Apex was used. The limit of detection (LOD of Pu was determined. The efficiency of Pu recovery from soil samples varies from 70 to 93%.

  1. Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Perdian, David C. [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.

  2. Reliability of a Cryoscopic Micro-Osmometer Using 15-µL Plasma Samples to Measure Hydration Status in Varied Environmental Conditions

    Science.gov (United States)

    Scanlan, Aaron T.; Richter-Stretton, Gina L.; Madueno, Maria C.; Borges, Nattai R.; Fenning, Andrew S.

    2017-01-01

    Measurement of plasma osmolality (P[subscript osm]) remains popular for assessing hydration status in exercise science. However, a controlled reliability assessment of micro-osmometry using small sample volumes to measure Posm remains to be performed. This study aimed to examine the reliability of a cryoscopic micro-osmometer requiring 15-µL…

  3. Reliability of a Cryoscopic Micro-Osmometer Using 15-µL Plasma Samples to Measure Hydration Status in Varied Environmental Conditions

    Science.gov (United States)

    Scanlan, Aaron T.; Richter-Stretton, Gina L.; Madueno, Maria C.; Borges, Nattai R.; Fenning, Andrew S.

    2017-01-01

    Measurement of plasma osmolality (P[subscript osm]) remains popular for assessing hydration status in exercise science. However, a controlled reliability assessment of micro-osmometry using small sample volumes to measure Posm remains to be performed. This study aimed to examine the reliability of a cryoscopic micro-osmometer requiring 15-µL…

  4. Usefulness of whole blood, plasma, peritoneal fluid, and peritoneal fluid supernatant glucose concentrations obtained by a veterinary point-of-care glucometer to identify septic peritonitis in dogs with peritoneal effusion.

    Science.gov (United States)

    Koenig, Amie; Verlander, Lindsey Lane

    2015-11-01

    To evaluate the usefulness of a veterinary point-of-care glucometer for identification of septic peritonitis in dogs with peritoneal effusion (PE). Prospective clinical evaluation. 39 dogs with PE. Blood and peritoneal fluid convenience samples were collected concurrently in all dogs at the time of initial evaluation. A veterinary point-of-care glucometer was used to measure glucose concentration in heparinized whole blood, plasma, peritoneal fluid, and peritoneal fluid supernatant samples. Seventeen dogs had confirmed septic peritonitis, and 22 dogs had nonseptic PE. Sensitivity, specificity, positive and negative predictive values, and accuracy of identification of dogs with septic peritonitis were calculated for glucose concentration differences for whole blood versus peritoneal fluid (WB-PF), plasma versus peritoneal fluid (P-PF), and plasma versus peritoneal fluid supernatant (P-PFS). With a cutoff of > 20 mg/dL, the glucose concentration difference for WB-PF was an insensitive indicator of septic peritonitis (sensitivity, 41.2%; specificity, 100%). In comparison, the glucose concentration differences for P-PF and P-PFS had a higher sensitivity for septic peritonitis (88.2% and 82.4%, respectively) but a lower specificity (80% and 77.8%, respectively). With a glucose concentration difference cutoff of ≥ 38 mg/dL, specificity, positive predictive value, and accuracy of P-PF and P-PFS improved. Determination of the glucose concentration difference for WB-PF with the veterinary point-of-care glucometer was not useful in identifying all dogs with septic peritonitis. A glucose concentration difference of ≥ 38 mg/dL for P-PF or P-PFS, however, supported an accurate diagnosis of septic peritonitis in dogs with PE.

  5. Evaluation of seasonal and daily changes of plasma thyroxine and cortisol levels in wild masu salmon Oncorhynchus masou, sampled by a Japanese fishing method.

    Science.gov (United States)

    Munakata, A; Miura, G; Matsuda, H

    2014-10-01

    A new fish sampling method was developed using a Japanese bait fishing rod (8-9 m carbon rod and a nylon line with a small fine wire single hook), which is considered to catch wild salmonid juveniles with low sampling stress. Using this method, seasonal and daily changes of plasma thyroxine (T4 ) and cortisol levels were examined in wild parr, pre-smolts and smolts of masu salmon Oncorhynchus masou in contiguous locations in a coastal river (Kesen River; 44 km) in northern Honshu Island, Japan, overlapping the period of smoltification and seaward migration from August to March. Plasma T4 and cortisol were low in 0+ and 1+ year parr caught in August and September. In March, some yearling (1+ year) fish, which were judged as pre-smolts, and smolts appeared mainly in mid and lower reaches, while parr (0+ and 1+ year parr) continued to appear in the upper and mid reaches. In March, 1+ year pre-smolts and smolts showed high plasma T4 levels while the levels of 1+ year parr were low. During March 2008-2010, plasma T4 levels of 1+ year pre-smolts and smolts had high levels from early to mid-March, whereas plasma cortisol levels of 1+ year smolts were low in early March and increased towards mid-March. Based on these data, plasma cortisol increases probably occur following the increases of plasma T4 levels to lead the 1+ year O. masou to the completion of smoltification and initiation of seaward migration. © 2014 The Fisheries Society of the British Isles.

  6. Quantification of carbamazepine, carbamazepine-10,11-epoxide, phenytoin and phenobarbital in plasma samples by stir bar-sorptive extraction and liquid chromatography.

    Science.gov (United States)

    Queiroz, Regina Helena Costa; Bertucci, Carlo; Malfará, Wilson Roberto; Dreossi, Sônia Aparecida Carvalho; Chaves, Andréa Rodrigues; Valério, Daniel Augusto Rodrigues; Queiroz, Maria Eugênia Costa

    2008-09-29

    A sensitive and reproducible stir bar-sorptive extraction and high-performance liquid chromatography-UV detection (SBSE/HPLC-UV) method for therapeutic drug monitoring of carbamazepine, carbamazepine-10,11-epoxide, phenytoin and phenobarbital in plasma samples is described and compared with a liquid:liquid extraction (LLE/HPLC-UV) method. Important factors in the optimization of SBSE efficiency such as pH, extraction time and desorption conditions (solvents, mode magnetic stir, mode ultrasonic stir, time and number of steps) assured recoveries ranging from 72 to 86%, except for phenytoin (62%). Separation was obtained using a reverse phase C18 column with UV detection (210nm). The mobile phase consisted of water:acetonitrile (78:22, v/v). The SBSE/HPLC-UV method was linear over a working range of 0.08-40.0microgmL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125-40.0microgmL(-1) for phenytoin, The intra-assay and inter-assay precision and accuracy were studied at three concentrations (1.0, 4.0 and 20.0microgmL(-1)). The intra-assay coefficients of variation (CVs) for all compounds were less than 8.8% and all inter-CVs were less than 10%. Limits of quantification were 0.08microgmL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125microgmL(-1) for phenytoin. No interference of the drugs normally associated with antiepileptic drugs was observed. Based on figures of merit results, the SBSE/HPLC-UV proved adequate for antiepileptic drugs analyses from therapeutic levels. This method was successfully applied to the analysis of real samples and was as effective as the LLE/HPLC-UV method.

  7. Relationship between cyclosporine concentrations obtained using the Roche Cobas Integra and Abbott TDx monoclonal immunoassays in pre-dose and two hour post-dose blood samples from kidney transplant recipients.

    Science.gov (United States)

    Garrido, Manuel J; Hermida, Jesús; Tutor, J Carlos

    2002-12-01

    Current evidence suggests that cyclosporine (CsA) concentration in blood samples taken 2 hours after Neoral microemulsion (Novartis Pharmaceuticals; East Hanover, NJ) administration (C2) predicts clinical events in transplant patients better than the pre-dose (trough) concentration (C0). Similarly, previous findings have shown that the metabolites/CsA ratio is substantially lower in C2 than in C0 samples; however the between-monoclonal immunoassay differences for C2 samples have received little attention in the literature. In 56 C samples and 60 C samples from renal transplant patients, CsA levels were determined using the monoclonal fluorescence polarization immunoassay (mFPIA) from Abbott (Abbott Park, IL) and the homogeneous enzyme immunoassay technique (HEIT) from Roche Diagnostics (Basel, Switzerland). In both cases a high correlation coefficient between the results was obtained (r > or = 0.971), with a linear regression for C0 samples: mFPIA = 1.47 HEIT + 22.0 and for C2 samples: mFPIA = 1.11 HEIT + 71.96. The difference between the linear regression slopes was statistically significant (P < 0.001), and the mFPIA/HEIT ratio was significantly higher for C than for C samples (P < 0.001).

  8. Multicomponent kinetic spectrophotometric determination of pefloxacin and norfloxacin in pharmaceutical preparations and human plasma samples with the aid of chemometrics

    Science.gov (United States)

    Ni, Yongnian; Wang, Yong; Kokot, Serge

    2008-10-01

    A spectrophotometric method for the simultaneous determination of the important pharmaceuticals, pefloxacin and its structurally similar metabolite, norfloxacin, is described for the first time. The analysis is based on the monitoring of a kinetic spectrophotometric reaction of the two analytes with potassium permanganate as the oxidant. The measurement of the reaction process followed the absorbance decrease of potassium permanganate at 526 nm, and the accompanying increase of the product, potassium manganate, at 608 nm. It was essential to use multivariate calibrations to overcome severe spectral overlaps and similarities in reaction kinetics. Calibration curves for the individual analytes showed linear relationships over the concentration ranges of 1.0-11.5 mg L -1 at 526 and 608 nm for pefloxacin, and 0.15-1.8 mg L -1 at 526 and 608 nm for norfloxacin. Various multivariate calibration models were applied, at the two analytical wavelengths, for the simultaneous prediction of the two analytes including classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), radial basis function-artificial neural network (RBF-ANN) and principal component-radial basis function-artificial neural network (PC-RBF-ANN). PLS and PC-RBF-ANN calibrations with the data collected at 526 nm, were the preferred methods—%RPE T ˜ 5, and LODs for pefloxacin and norfloxacin of 0.36 and 0.06 mg L -1, respectively. Then, the proposed method was applied successfully for the simultaneous determination of pefloxacin and norfloxacin present in pharmaceutical and human plasma samples. The results compared well with those from the alternative analysis by HPLC.

  9. Analysis of imatinib in bone marrow and plasma samples of chronic myeloid leukaemia patients using solid phase extraction LC-ESI-MS

    OpenAIRE

    Iqbal, Z; Elliott, M; Watson, D.G.; Holyoake, T. L.; Jorgensen, H G

    2011-01-01

    The LC-ESI-MS was developed and validated for the analysis of imatinib in plasma and bone marrow samples using deuterated imatinib (D(8)-IM) as an internal standard. The biological samples were extracted using Strata-X-C SPE cartridges and separated on C8 column (50 x 3 mm, 3 µm), and methanol: 0.1% formic acid (70:30) was delivered at the rate of 0.7 ml/min as a mobile phase. Imatinib was quantified in samples by monitoring the ions m/z 494.3 for imatinib and 502.3 for D8-imatinib on ma...

  10. Plasma retinol and association with socio-demographic and dietary characteristics of free-living older persons: the Bordeaux sample of the three-city study.

    Science.gov (United States)

    Féart, Catherine; Siewe, Aisha; Samieri, Cécilia; Peuchant, Evelyne; Helmer, Catherine; Alfos, Serge; Pallet, Véronique; Barberger-Gateau, Pascale

    2010-01-01

    The objective was to describe retinol plasma concentration and its association with socio-demographic characteristics and dietary habits in French older persons. The study population consisted of 1664 subjects aged 65 + from Bordeaux (France), included in the Three-City cohort. Retinol plasma concentration was determined in fasting blood samples. Dietary assessment was performed by a food frequency questionnaire allowing estimation of weekly intake of dietary sources of vitamin A or provitamin A. The weekly number of glasses of alcohol was also recorded. Age, sex, marital status, educational and income levels, body-mass index (BMI), and smoking were registered. Cross-sectional analysis of the association between plasma retinol and socio-demographic characteristics and dietary habits was performed by multilinear regression. Mean plasma retinol was close to the homeostatically regulated concentration of 2.0 micromol/L but ranged from 0.35 to 6.77 micromol/L. It was higher in women and divorced or separated individuals, and increased with income but not with age or educational level. Plasma retinol was positively and independently associated with the frequency of offal consumption and to the number of glasses of alcohol consumed per week. These results allow targeting older individuals who are at risk of either excessive or deficient vitamin A status and who should benefit from dietary counseling.

  11. Obtaining of Tokamak Plasma Impurities Emissivities Profiles by Using Matrix Inversion Method%矩阵求逆应用于等离子体杂质体发射率测量的研究

    Institute of Scientific and Technical Information of China (English)

    沈永才; 程飞; 吴义恒

    2016-01-01

    In this paper,process of obtaining impurity emissivity on tokamak plasma has been studied .By using matrix inver-sion, emissivity can be calculated according to brightness of impurity spectral lines .As an example, Mo emissivities have been cal-culated by using this method based on the assumed brightness .%对托卡马克等离子体中获得杂质局部体发射率的过程进行研究,提出了一种采用求逆矩阵的方法进行 A-bel反演,根据弦积分的杂质光亮度分布获得杂质局部体发射率。结合托卡马克装置假象的钼杂质弦积分剖面,采用该方法获得了杂质的体发射率分布。

  12. An ultrasound-assisted digestion method for the determination of toxic element concentrations in ash samples by inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Ilander, Aki; Väisänen, Ari

    2007-10-29

    A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of toxic element concentrations (arsenic, barium, cobalt, copper, lead, nickel, strontium, vanadium and zinc) in ash samples was developed. All the measurements were performed in robust plasma conditions which were tested by measuring the Mg(II) 280.270 nm/Mg(I) 285.213 nm line intensity ratios. The highest line intensity ratios were observed when a nebulizer gas flow of 0.6 L min(-1), auxiliary gas flow of 0.2 L min(-1) and plasma power of 1400 W were used for radially viewed plasma. The analysis of SRM 1633b showed that the ultrasound-assisted method developed is highly comparable with the microwave digestion method standardized by the United States Environmental Protection Agency (EPA-3052). The ultrasound-assisted digestion with a digestion solution of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 81%. One exception is arsenic which resulted in recoveries of about 60% only; however, it could be digested with good recovery (>90%) using a digestion solution of 5 mL of water and 5 mL of aqua regia. The major advantage of the ultrasound-assisted digestion over microwave digestion is the high treatment rate (30 samples simultaneously with a sonication time of 18 min).

  13. Comparison of three methods for detecting epidermal growth factor receptor mutations in plasma DNA samples of Chinese patients with advanced non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    QIN Ling; ZHONG Wei; ZHANG Li; LI Long-yun; WANG Meng-zhao

    2011-01-01

    Background Epidermal growth factor receptor (EGFR) mutations can predict tumor response to tyrosine kinase inhibitors (TKIs). Detecting EGFR mutations in plasma DNA samples in patients with advanced non-small cell lung cancer is challenging and promising. We compared three methods for detecting plasma EGFR mutations, including direct DNA sequencing, denaturing high-performance liquid chromatography (DHPLC) and Scorpions Amplification Refractory Mutation System (Scorpions ARMS).Methods Plasma DNA samples from 73 patients with stage ⅢB to Ⅳ adenocarcinoma were analyzed for EGFR mutations in exons 19 (deletion mutation) and 21(L858R mutation) using direct DNA sequencing, DHPLC and Scorpions ARMS. Sensitivities of the three methods were compared and the relationship between EGFR mutations and patients'survival was analyzed.Results In 73 patients, we detected EGFR mutations in 5 samples (6.9%) by direct DNA sequencing, in 22 samples (30.1%) by DHPLC, and in 28 samples (38.4%) by Scorpions ARMS. EGFR mutations were found in 13 samples in exon 19 and in 9 samples in exon 21 by DHPLC, while we found mutations in 15 samples in exon 19 and in 13 samples in exon 21 by Scorpions ARMS. Among the 73 patients, there was 90.4% concordance between DHPLC and Scorpions ARMS (66/73, K=0.79, P=0.07). Of the 73 patients, 46 patients were treated with gefitinib, including 18 patients with mutations and 28 patients without mutations as determined by Scorpions ARMS. The 18 patients with mutations had a significantly longer progression-free survival (PFS) time (median PFS was 21.0 months) than the 28 patients without mutations (median PFS was 7.0 months) (P=0.022).Conclusions Among the three methods for detecting EGFR mutations in plasma DNA samples of patients with advanced lung adenocarcinoma, direct gene sequencing had the lowest sensitivity, while Scorpion ARMS showed the highest mutation detecting capability. DHPLC is slightly less sensitive than Scorpion ARMS. EGFR

  14. Determination of metoprolol enantiomers in human plasma and saliva samples utilizing microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Elmongy, Hatem; Ahmed, Hytham; Wahbi, Abdel-Aziz; Amini, Ahmad; Colmsjö, Anders; Abdel-Rehim, Mohamed

    2016-08-01

    A sensitive, accurate and reliable bioanalytical method for the enantioselective determination of metoprolol in plasma and saliva samples utilizing liquid chromatography-electrospray ionization tandem mass spectrometry was developed and validated. Human plasma and saliva samples were pretreated by microextraction by packed sorbent (MEPS) prior to analysis. A new MEPS syringe form with two inputs was used. Metoprolol enantiomers and internal standard pentycaine (IS) were eluted from MEPS sorbent using isopropanol after removal of matrix interferences using aliquots of 5% methanol in water. Complete separation of metoprolol enantiomers was achieved on a Cellulose-SB column (150 × 4.6 mm, 5 μm) using isocratic elution with mobile phase 0.1% ammonium hydroxide in hexane-isopropanol (80:20, v/v) with a flow rate of 0.8 mL/min. A post-column solvent-assisted ionization was applied to enhance metoprolol ionization signal in positive mode monitoring (+ES) using 0.5% formic acid in isopropanol at a flow rate of 0.2 mL/min. The total chromatographic run time was 10 min for each injection. The detection of metoprolol in plasma and saliva samples was performed using triple quadrupole tandem mass spectrometer in +ES under the following mass transitions: m/z 268.08 → 72.09 for metoprolol and m/z 303.3 → 154.3 for IS. The linearity range was 2.5-500 ng/mL for both R- and S-metoprolol in plasma and saliva. The limits of detection and quantitation for both enantiomers were 0.5 and 2.5 ng/mL respectively, in both matrices (plasma and saliva). The intra- and inter-day precisions were presented in terms of RSD values for replicate analysis of quality control samples and were metoprolol enantiomers in both human plasma and saliva samples successfully, which can aid in therapeutic drug monitoring in clinical laboratories. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Comparison of the Hologic Aptima HIV-1 Quant Dx Assay to the Roche COBAS Ampliprep/COBAS TaqMan HIV-1 Test v2.0 for the quantification of HIV-1 RNA in plasma samples

    DEFF Research Database (Denmark)

    Schønning, Kristian; Johansen, Kim; Landt, Bodil

    2017-01-01

    of the Aptima HIV-1 Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HIV-1 Test v2.0 (CAPCTMv2) for the quantification of HIV-1 RNA in plasma samples. STUDY DESIGN: The performance of the two tests was compared on 216 clinical plasma samples, on dilutions series in seven replicates of five clinical...

  16. Simultaneous extraction and quantification of lamotrigine, phenobarbital, and phenytoin in human plasma and urine samples using solidified floating organic drop microextraction and high-performance liquid chromatography.

    Science.gov (United States)

    Asadi, Mohammad; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Abbasi, Bijan

    2015-07-01

    A novel and simple method based on solidified floating organic drop microextraction followed by high-performance liquid chromatography with ultraviolet detection has been developed for simultaneous preconcentration and determination of phenobarbital, lamotrigine, and phenytoin in human plasma and urine samples. Factors affecting microextraction efficiency such as the type and volume of the extraction solvent, sample pH, extraction time, stirring rate, extraction temperature, ionic strength, and sample volume were optimized. Under the optimum conditions (i.e. extraction solvent, 1-undecanol (40 μL); sample pH, 8.0; temperature, 25°C; stirring rate, 500 rpm; sample volume, 7 mL; potassium chloride concentration, 5% and extraction time, 50 min), the limits of detection for phenobarbital, lamotrigine, and phenytoin were 1.0, 0.1, and 0.3 μg/L, respectively. Also, the calibration curves for phenobarbital, lamotrigine, and phenytoin were linear in the concentration range of 2.0-300.0, 0.3-200.0, and 1.0-200.0 μg/L, respectively. The relative standard deviations for six replicate extractions and determinations of phenobarbital, lamotrigine, and phenytoin at 50 μg/L level were less than 4.6%. The method was successfully applied to determine phenobarbital, lamotrigine, and phenytoin in plasma and urine samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Combining single-particle inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy to evaluate the release of colloidal arsenic from environmental samples.

    Science.gov (United States)

    Gomez-Gonzalez, Miguel Angel; Bolea, Eduardo; O'Day, Peggy A; Garcia-Guinea, Javier; Garrido, Fernando; Laborda, Francisco

    2016-07-01

    Detection and sizing of natural colloids involved in the release and transport of toxic metals and metalloids is essential to understand and model their environmental effects. Single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was applied for the detection of arsenic-bearing particles released from mine wastes. Arsenic-bearing particles were detected in leachates from mine wastes, with a mass-per-particle detection limit of 0.64 ng of arsenic. Conversion of the mass-per-particle information provided by SP-ICP-MS into size information requires knowledge of the nature of the particles; therefore, synchrotron-based X-ray absorption spectroscopy (XAS) was used to identify scorodite (FeAsO4·2H2O) as the main species in the colloidal particles isolated by ultrafiltration. The size of the scorodite particles detected in the leachates was below 300-350 nm, in good agreement with the values obtained by TEM. The size of the particles detected by SP-ICP-MS was determined as the average edge of scorodite crystals, which show a rhombic dipyramidal form, achieving a size detection limit of 117 nm. The combined use of SP-ICP-MS and XAS allowed detection, identification, and size determination of scorodite particles released from mine wastes, suggesting their potential to transport arsenic. Graphical abstract Analytical approach for the detection and size characterization of As-bearing particles by SP-ICP-MS and XAS in environmental samples.

  18. Pre-storage centrifugation conditions have significant impact on measured microRNA levels in biobanked EDTA plasma samples

    DEFF Research Database (Denmark)

    Binderup, Helle Glud; Houlind, Kim; Madsen, Jonna Skov;

    2016-01-01

    was significantly higher in the re-centrifuged biobanked plasma compared to PPP, even when the platelet count was reduced to 0-1×109/L. Conclusion: We found, that pre-storage centrifugation conditions have a significant impact on the measured EDTA plasma level of miRNAs known to be present in platelets. Even......Background: In the past few years, an increasing number of studies have reported the potential use of microRNAs (miRNA) as circulating biomarkers for diagnosis or prognosis of a wide variety of diseases. There is, however, a lack of reproducibility between studies. Due to the high miRNA content...

  19. Electrospray ionization-ion mobility spectrometry as a detection system for three-phase hollow fiber microextraction technique and simultaneous determination of trimipramine and desipramine in urine and plasma samples.

    Science.gov (United States)

    Jafari, M T; Saraji, M; Sherafatmand, H

    2011-04-01

    A novel method based on three-phase hollow fiber microextraction technique (HF-LPME) coupled with electrospray ionization-ion mobility spectrometry (ESI-IMS) was developed for the simultaneous determination of two antidepressant drugs (trimipramine and desipramine) in urine and plasma samples. The effects of various parameters such as type of organic solvent, composition of donor and acceptor phase, stirring rate, salt addition, extraction time, and temperature were investigated. Under the optimized conditions, the relative standard deviation was in the range of 5-6%, and the method quantitation limit (MQL) of utilizing HF-LPME/ESI-IMS was 5 μg/L for both drugs. The relative recoveries obtained by the proposed method from urine and plasma samples were in the range 94% to 97% for trimipramine and 92% to 96% for desipramine. Finally, the feasibility of the proposed method was successfully confirmed by extraction and determination of trace amounts of trimipramine and desipramine in biological samples without any significant matrix effect.

  20. Analysis of drugs in plasma samples from schizophrenic patients by column-switching liquid chromatography-tandem mass spectrometry with organic-inorganic hybrid cyanopropyl monolithic column.

    Science.gov (United States)

    Domingues, Diego Soares; Souza, Israel Donizeti de; Queiroz, Maria Eugênia Costa

    2015-07-01

    This study reports on the development of a rapid, selective, and sensitive column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyze sixteen drugs (antidepressants, anticonvulsants, anxiolytics, and antipsychotics) in plasma samples from schizophrenic patients. The developed organic-inorganic hybrid monolithic column with cyanopropyl groups was used for the first dimension of the column-switching arrangement. This arrangement enabled online pre-concentration of the drugs (monolithic column) and their subsequent analytical separation on an XSelect SCH C18 column. The drugs were detected on a triple quadrupole tandem mass spectrometer (multiple reactions monitoring mode) with an electrospray ionization source in the positive ion mode. The developed method afforded adequate linearity for the sixteen target drugs; the coefficients of determination (R(2)) lay above 0.9932, the interassay precision had coefficients of variation lower than 6.5%, and the relative standard error values of the accuracy ranged from -14.0 to 11.8%. The lower limits of quantification in plasma samples ranged from 63 to 1250pgmL(-1). The developed method successfully analyzed the target drugs in plasma samples from schizophrenic patients for therapeutic drug monitoring (TDM).

  1. Comparison of sample preparation methods for the quantitative analysis of eicosanoids and other oxylipins in plasma by means of LC-MS/MS.

    Science.gov (United States)

    Ostermann, Annika I; Willenberg, Ina; Schebb, Nils Helge

    2015-02-01

    Oxylipins are potent lipid mediators. For the evaluation of their biological roles, several LC-MS based methods have been developed. While these methods are similar, the described sample preparation procedures for the extraction of oxylipins differ considerably. In order to deduce the most appropriate method for the analysis of non-esterified oxylipins in human plasma, we evaluated the performance of seven established sample preparation procedures. Six commonly used solid phase extraction (SPE) and one liquid-liquid extraction (LLE) protocol were compared based on the recovery of 13 added internal standards, extraction efficacy of oxylipins from plasma and reduction of ion-suppressing matrix. Dramatic differences in the performance in all three parameters were found. LLE with ethyl acetate was overall not a sufficient sample preparation strategy. The protocols using Oasis- and StrataX-material insufficiently removed interfering matrix compounds. Extraction efficacy of oxylipins on anion-exchanging BondElut cartridges was low, while removal of matrix was nearly perfect. None of the protocols led to a high extraction efficacy of analytes while removing all interfering matrix components. However, SPE on a C18-material with removal of matrix by water and n-hexane prior elution with methyl formate showed the best performance for the analysis of a broad spectrum of oxylipins in plasma.

  2. Molecularly imprinted polymer in microextraction by packed sorbent for the simultaneous determination of local anesthetics: lidocaine, ropivacaine, mepivacaine and bupivacaine in plasma and urine samples.

    Science.gov (United States)

    Daryanavard, Seyed Mosayeb; Jeppsson-Dadoun, Amin; Andersson, Lars I; Hashemi, Mahdi; Colmsjö, Anders; Abdel-Rehim, Mohamed

    2013-11-01

    This study presents the use of molecularly imprinted polymer (MIP) as packing material for microextraction by packed syringe (MEPS) to achieve higher extraction selectivity. Pentycaine was used as template for MIP. Development and validation of the determination of lidocaine, ropivacaine, mepivacaine and bupivacaine in human plasma and urine samples utilizing MIP-MEPS and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were carried out. The MEPS MIP-cartridge could be used for 100 extractions before it was discarded. The extraction recovery ranged from 60 to 80%. The correlation coefficients values were >0.999 for all assays using lidocaine, ropivacaine, mepivacaine and bupivacaine in the calibration range 5-2000 nmol/L. The accuracy of the studied compounds, given as a percentage variation from the nominal concentration values, ranged from -4.9 to 8.4% using plasma and urine samples. The between-batch precision, given as the relative standard deviation, at three different concentrations (quality control samples) was ranged from -4.7 to 14.0% and from 1.8 to 12.7% in plasma and urine, respectively. The lower limit of quantification and limit of detection of the studied substances were 5.0 and 1.0 nm, respectively. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Plasma cortisol and noradrenalin concentrations in pigs: automated sampling of freely moving pigs housed in PigTurn versus manually sampled and restrained pigs

    Science.gov (United States)

    Minimizing the effects of restraint and human interaction on the endocrine physiology of animals is essential for collection of accurate physiological measurements. Our objective was to compare stress-induced cortisol (CORT) and noradrenalin (NorA) responses in automated versus manual blood sampling...

  4. 铁铝混合粉热喷涂及扩散处理组织分析%Microstructure of Coatings Obtained by Air Plasma Spray of Iron and Aluminium Powders

    Institute of Scientific and Technical Information of China (English)

    闵学刚; 余新泉; 孙扬善; 冯文博; 孙建荣

    2001-01-01

    The coatings of mixed iron aluminides and oxide phases on 18-8 stainless steel substrates were obtained by air plasma spraying mixed powder of iron and aluminium.Microstructures of coatings were investigated by optical microscope,SEM and XRD.The results show that reactions between iron and aluminium sprayed through plasma torch in high speed take place when melted spray of iron and aluminium impinge on the 18-8 stainless steel substrates.Microstructure observations also find the joint of the coatings and substrates is fine and no cracks have been observed.The amount of iron aluminides in coatings increases after the diffusion treatment at 600℃.After the coatings were diffusionally treated at 800℃ and 1000℃,pure Al in coatings disappears completely,but pure Fe still remains,the coatings consist of pure Fe,iron aluminides and oxide phases.%利用等离子喷涂方法在不锈钢基体上喷涂铁铝混合粉获得了铁铝涂层,并对涂层的组织进行了分析。研究结果表明,Fe粉和Al粉熔化后由喷枪高速喷出,沉积在基体上可发生部分化合反应,生成少量的铁铝金属间化合物,涂层与基体结合良好。600℃扩散处理后,涂层中的铁铝金属间化合物增多。800℃和1000℃扩散处理后,Al全部反应,Fe有剩余,涂层由Fe、铁铝金属间化合物和氧化物组成。

  5. A novel and cost effective method of removing excess albumin from plasma/serum samples and its impacts on LC-MS/MS bioanalysis of therapeutic proteins.

    Science.gov (United States)

    Liu, Guowen; Zhao, Yue; Angeles, Aida; Hamuro, Lora L; Arnold, Mark E; Shen, Jim X

    2014-08-19

    We have developed an innovative method to remove albumin from plasma/serum samples for the LC-MS/MS quantitation of therapeutic proteins. Different combinations of organic solvents and acids were screened for their ability to remove albumin from plasma and serum samples. Removal efficiency was monitored by two signature peptides (QTALVELVK and LVNEVTEFAK) from albumin. Isopropanol with 1.0% trichloroacetic acid was found to be the most effective combination to remove albumin while retaining the protein of interest. Our approach was compared with a commercial albumin depletion kit on both efficiency of albumin removal and recovery of target proteins. We have demonstrated that our approach can remove 95% of the total albumin in human plasma samples while retaining close to 100% for two of three therapeutic proteins tested, with the third one at 60-80%. The commercial kit removed 98% of albumin but suffered at least 50% recovery loss for all therapeutic proteins when compared to our approach. Using BMS-C as a probe compound, the incorporation of the albumin removal approach has improved both assay sensitivity and ruggedness, compared to the whole plasma protein digestion approach alone. An LC-MS/MS method was developed and validated based on this new approach for the analysis of BMS-C in monkey serum. This assay was successfully applied to a toxicological study. When the albumin removal method was used in another clinical LC-MS/MS method, the sensitivity improved 10-fold to 50 ng/mL LLOQ comparing to a typical pellet digestion method.

  6. Reliable LC-MS/MS assay for the estimation of rilpivirine in human plasma: application to a bioequivalence study and incurred sample reanalysis.

    Science.gov (United States)

    Gupta, Ajay; Guttikar, Swati; Patel, Yogesh; Shrivastav, Pranav S; Sanyal, Mallika

    2015-04-01

    A simple, precise, and rapid stable isotope dilution liquid chromatography-tandem mass spectrometry method has been developed and validated for the quantification of rilpivirine, a non-nucleoside reverse transcriptase inhibitor in human plasma. Rilpivirine and its deuterated analogue, rilpivirine-d6, used as an internal standard (IS) were quantitatively extracted by liquid-liquid extraction with methyl-tert-butyl ether and diethyl ether solvent mixture from 50 μL plasma. The chromatography was achieved on Gemini C18 (150 × 4.6 mm, 5 µm) analytical column in a run time of 2.2 min. The precursor → product ion transitions for rilpivirine (m/z 367.1 → 128.0) and IS (m/z 373.2 → 134.2) were monitored on a triple quadrupole mass spectrometer in the positive ionization mode. The linearity of the method was established in the concentration range of 0.5-200 ng/mL. The mean extraction recovery for rilpivirine (94.9%) and IS (99.9%) from spiked plasma samples was consistent and reproducible. The IS-normalized matrix factors for rilpivirine ranged from 0.98 to 1.02 across three quality controls. Bench top, freeze-thaw, wet extract, and long-term stability of rilpivirine was examined in spiked plasma samples. The application of the method was demonstrated by a bioequivalence study with 25 mg rilpivirine tablet formulation in 40 healthy subjects. The assay reproducibility was shown by reanalysis of 200 study samples and the % change in the concentration of repeat values from the original values was within ±15%.

  7. Analytical sample preparation strategies for the determination of antimalarial drugs in human whole blood, plasma and urine

    DEFF Research Database (Denmark)

    Casas, Monica Escolà; Hansen, Martin; Krogh, Kristine A;

    2014-01-01

    Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urin...... summarized. Finally, the main problems that the researchers have dealt with are highlighted. This information will aid analytical chemists in the development of novel methods for determining existing antimalarials and upcoming new drugs.......Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urine...

  8. A New Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Bisoprolol in Human Plasma Samples

    OpenAIRE

    Gabriela Peste; Nela Bibire; Mihai Apostu; Aurel Vlase; Corneliu Oniscu

    2009-01-01

    Liquid chromatography (LC) coupled with mass spectrometry (MS) detection is one of the most powerful analytical tools for organic compound analysis. The advantages of using LC/MS methods over HPLC methods include: selectivity, chromatographic integrity, peak assignment, structural information, and rapid method development. In this paper, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the determination of bisoprolol in human plasma s...

  9. Determination of Cu, Mn, Ni and Sn in gasoline by electrothermal vaporization inductively coupled plasma mass spectrometry, and emulsion sample introduction

    Science.gov (United States)

    Saint'Pierre, Tatiana D.; Dias, Lúcia Felicidade; Pozebon, Dirce; Aucélio, Ricardo Q.; Curtius, Adilson J.; Welz, Bernhard

    2002-12-01

    Trace metals in fuels, except in the case of additives, are usually undesirable and normally they occur in very low concentrations in gasoline, requiring sensitive techniques for their determination. Coupling of electrothermal vaporization with inductively coupled plasma mass spectrometry minimizes the problems related to the introduction of organic solvents into the plasma. Furthermore, sample preparation as oil-in-water emulsions reduces problems related to gasoline analysis. In this work, a method for determination of Cu, Mn, Ni and Sn in gasoline is proposed. Samples were prepared by forming a 10-fold diluted emulsion with a surfactant (Triton X-100), after treatment with concentrated HNO 3. The sample emulsion was pre-concentrated in the graphite tube by repeated pipetting and drying. External calibration was used with aqueous standards in a purified gasoline emulsion. Six samples from different gas stations were analyzed, and the analyte concentrations were found to be in the μg l -1 range or below. The limits of detection were 0.22, 0.02, 0.38 and 0.03 μg l -1 for Cu, Mn, Ni and Sn, respectively. The accuracy of the method was estimated using a recovery test.

  10. Solidified floating organic drop microextraction combined with high performance liquid chromatography for the determination of carbamazepine in human plasma and urine samples

    Institute of Scientific and Technical Information of China (English)

    Mohammad ASADI; Ali Mohammad HAJI SHABANI; Shayessteh DADFARNIA; Bijan ABBASI

    2015-01-01

    Solidified floating organic drop microextraction( SFODME)in combination with high performance liquid chromatography was used for separation/preconcentration and determination of carbamazepine( CBZ)in human plasma and urine samples. Parameters that affect the extraction efficiency such as the type and volume of extraction solvent,ionic strength,sodium hydroxide concentration,stirring rate,sample volume and extrac-tion time,were investigated and optimized. Under the optimum conditions( extraction solvent,40 μL of 1-un-decanol;sodium hydroxide concentration,1 mol/L;temperature,50 ℃;stirring speed,400 r/min;sample vol-ume,8 mL;sodium chloride concentration,3%( w/v)and extraction time,60 min)the calibration curve was found to be linear in the mass concentration range of 0. 4-700. 0 μg/L. The limit of detection( LOD)was 0. 1μg/L and the relative standard deviation( RSD)for six replicate extraction and determination of carbamazepine at 100 μg/L level was found to be 4. 1%. The method was successfully applied to the determination of CBZ in human plasma and urine samples.

  11. The determination of trace element concentrations in fly ash samples using ultrasound-assisted digestion followed with inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Ilander, Aki; Väisänen, Ari

    2009-08-01

    A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element (chromium, copper, lead, nickel, vanadium and zinc) concentrations in fly ash samples was developed. All the measurements were performed in robust plasma conditions. Ultrasound-assisted digestion procedures using digestion solutions of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 80% for all the analyte elements. Ultrasound-assisted two-step digestion with digestion solutions of 6mL of HNO(3) (Step 1) and 3mL of HNO(3)+3mL of HF (Step 2) resulted in recovery rates of over 92% for all the analyte elements with one exception, chromium, which had a recovery of about 85%. The analysis of SRM 1633b showed that the two-step ultrasound-assisted digestion method developed resulted in chromium, copper, nickel and zinc concentrations higher than the microwave digestion method standardized by the United States Environmental Protection Agency (USEPA method 3052). This is the very first time when a digestion method using ultrasound resulted in higher efficiency than microwave (USEPA method 3052) for chromium and nickel in very hard to dissolve samples. The major advantages of the ultrasound-assisted digestion over microwave digestion is the high treatment rate (about 30 samples simultaneously with a sonication time of 18min) and the possibility to use new sample vessels without a significant increase in costs.

  12. Pretreatment of plasma samples by a novel hollow fiber centrifugal ultrafiltration technique for the determination of plasma protein binding of three coumarins using acetone as protein binding releasing agent.

    Science.gov (United States)

    Li, Junmei; Shi, Qingwen; Jiang, Ye; Liu, Yan

    2015-09-15

    A novel and practical sample pretreatment method based on hollow fiber centrifugal ultrafiltration (HFCF-UF) was developed to determine plasma protein binding by using HPLC. The samples for analyzing unbound and total concentrations could be prepared in parallel simultaneously by the same device. It only required centrifugation for a short time and the filtrate could be injected directly for HPLC analysis without further treatment. Coumarins were selected as the model drugs. Acetone was chosen as the releasing agent to free the binding drug from the drug-protein complex for the total drug concentration determination. Non-specific bindings (NSBs) between the analytes and hollow fiber membrane materials were investigated. The type and volume of protein binding releaser were optimized. Additionally, centrifugal speed and centrifugal time were considered. Under the optimized conditions, the absolute recovery rates of the unbound and total concentrations were in the range of 97.5-100.9% for the three analytes. The limits of detection were in the range of 0.0135-0.0667μgmL(-1). In vitro plasma protein binding of the three coumarins was determined at three concentrations using the validated method and the relative standard deviations (RSDs) were less than 3.4%. Compared with traditional method, the HFCF-UF method is simple to run, no specialized equipment requirement and is a more accurate plasma pretreatment procedure with almost excellent drug-protein binding equilibrium. Therefore, this method can be applied to determine the plasma protein binding in clinical practice. It also provides a reliable alternative for accurate monitoring of unbound or total drug concentration in therapeutic drug monitoring (TDM).

  13. Cloud point extraction with/without chelating agent on-line coupled with inductively coupled plasma optical emission spectrometry for the determination of trace rare earth elements in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Li Yingjie [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Hu Bin, E-mail: binhu@whu.edu.cn [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2010-02-15

    The on-line incorporation of cloud point extraction (CPE) with/without 8-hydroxyquinoline (8-Ox) as chelating agent into flow injection analysis associated with inductively coupled plasma optical emission spectrometry (ICP-OES) for determining trace rare earth elements (REEs) is presented and evaluated. The significant parameters affecting on-line cloud point extraction of REEs such as sample pH, flow rate, 8-Ox concentration, Triton X-114 concentration were systematically studied. Under the optimized conditions, with the consumption of 3.0 mL sample solution, the limits of detection (3{sigma}) were ranged from 41.4 pg mL{sup -1} (Yb) to 448 pg mL{sup -1} (Gd) with relative standard deviations (RSDs) of 1.0% (Eu)-5.9% (Sm) for on-line CPE-ICP-OES with 8-Ox as chelating agent, and 69.0 pg mL{sup -1} (Sc) to 509.5 pg mL{sup -1} (Sm) with RSDs of 2.9% (Yb)-7.5% (Ho) for on-line CPE-ICP-OES without 8-Ox as chelating agent, respectively. The sample throughput of 17 samples h{sup -1} was obtained for both systems. The developed methods of on-line CPE-ICP-OES were validated by the analysis of certified reference material (GBW07605, tea leaves) and real biological samples of pig liver, Auricularia auricula and mushroom.

  14. Development and validation of an HPLC-MS/MS method to quantify clopidogrel acyl glucuronide, clopidogrel acid metabolite, and clopidogrel in plasma samples avoiding analyte back-conversion.

    Science.gov (United States)

    Silvestro, Luigi; Gheorghe, Mihaela; Iordachescu, Adriana; Ciuca, Valentin; Tudoroniu, Ariana; Rizea Savu, Simona; Tarcomnicu, Isabela

    2011-08-01

    A new sensitive and fast quantitative analytical method for the simultaneous determination of clopidogrel, its main metabolite clopidogrel carboxylic acid, and the newly described acyl glucuronide metabolite, in human plasma samples, is presented. The analytical procedures (plasma storage, handling, and extract storage in the autosampler) were optimized in order to avoid back-conversion; a known drawback in measurements of clopidogrel. Clopidogrel acyl glucuronide was confirmed as a major source of back-conversion to the parent drug in the presence of methanol, and thorough stability experiments were carried out to find the most appropriate conditions for an accurate analysis of clopidogrel and the two metabolites. The method was validated by assessing selectivity, sensitivity, linearity, accuracy, and precision for all three analytes, in accordance to Food and Drug Administration guidelines. Spiked quality controls in plasma as well as incurred samples were used to verify back-conversion in the selected conditions, with results meeting European Medicines Agency acceptance criteria (concentrations within 80-120% of the first reading). The method was then applied to a pharmacokinetic study, and for the first time, a pharmacokinetic curve of clopidogrel acyl glucuronide in human plasma is presented. The concentrations ranged up to 1,048.684 ng/mL, with a mean of 470.268 ng/mL, while clopidogrel had a mean C(max) of 1.348 ng/mL; these orders of magnitude show how much the back-conversion of this metabolite may influence clopidogrel quantification if it is not properly controlled.

  15. Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of Cr, Fe, Cu, Zn and Se in cereals

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shih-Yi [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Jiang, Shiuh-Jen, E-mail: sjjiang@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Sahayam, A.C. [National Centre for Compositional Characterisation of Materials (CCCM), Hyderabad (India)

    2014-11-01

    Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS) has been applied to determine Cr, Fe, Cu, Zn and Se in several cereal samples. Thioacetamide was used as the modifier to enhance the ion signals. The background ions at the masses of interest were reduced in intensity significantly by using 1.0 mL min{sup −1} methane (CH{sub 4}) as reaction cell gas in the dynamic reaction cell (DRC). Since the sensitivities of Cr, Fe, Cu, Zn and Se in different matrices were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Fe, Cu, Zn and Se in these cereal samples. The method detection limits estimated from standard addition curves were about 1, 10, 4, 12 and 2 ng g{sup −1} for Cr, Fe, Cu, Zn and Se, respectively, in original cereal samples. This procedure has been applied to the determination of Cr, Fe, Cu, Zn and Se whose concentrations are in μg g{sup −1} (except Cr and Se) in standard reference materials (SRM) of National institute of standards and technology (NIST), NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and two cereal samples purchased from a local market. The analysis results of reference materials agreed with certified values at 95% confidence level according to Student's T-test. The results for the real world cereal samples were also found to be in good agreement with the pneumatic nebulization DRC ICP-MS results of the sample solutions. - Highlights: • Determination of Cr, Fe, Cu, Zn and Se in cereal samples • Ultrasonic slurry sampling in combination with DRC-ICP-MS • Better sensitivity with thioacetamide modifier in ETV • Decreased sample preparation time with solid sampling • Validation with NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour.

  16. Arsenic speciation in seafood samples with emphasis on minor constituents. An investigation by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Pritzl, G.; Hansen, S. H.

    1993-01-01

    Extracts of 11 samples of shrimp, crab, fish, fish liver, shellfish and lobster digestive gland (hepatopancreas), including five certified reference materials, were investigated for their contents of arsenic compounds (arsenic speciation). The cation-exchange high performance liquid chromatography...... procedure was optimized to separate six cationic arsenicals present in the samples with internal chromatographic standardization by the trimethylselenonium ion, which was detected a m/z 82 (Se-82), in addition to arsenic at m/z 75, by inductively coupled plasma mass spectrometry. The content of each species...... gland, and another unknown (U2) was present at 0.2-6.4% in all samples. The contents of arsenite and arsenate were 0-1.4%, dimethylarsinate 8.2-29% while monomethylarsonate was detected only in oyster at 0.3% of the total extracted arsenic. Finding tetramethylarsonium ion and arsenocholine in a variety...

  17. Arsenic speciation in seafood samples with emphasis on minor constituents. An investigation by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Pritzl, G.; Hansen, S. H.

    1993-01-01

    procedure was optimized to separate six cationic arsenicals present in the samples with internal chromatographic standardization by the trimethylselenonium ion, which was detected a m/z 82 (Se-82), in addition to arsenic at m/z 75, by inductively coupled plasma mass spectrometry. The content of each species...... (as arsenic atom) relative to the total arsenic extracted from the samples were: arsenobetaine 19-98%, arsenocholine and trimethylarsine oxide 0-0.6% and the trimethylarsonium ion 0-2.2%. Additionally, an unknown arsenic species (U1) was present at 3.1-18% in the shellfish and in the lobster digestive...... gland, and another unknown (U2) was present at 0.2-6.4% in all samples. The contents of arsenite and arsenate were 0-1.4%, dimethylarsinate 8.2-29% while monomethylarsonate was detected only in oyster at 0.3% of the total extracted arsenic. Finding tetramethylarsonium ion and arsenocholine in a variety...

  18. Evaluation of the Biofire FilmArray BioThreat-E Test (v2.5) for Rapid Identification of Ebola Virus Disease in Heat-Treated Blood Samples Obtained in Sierra Leone and the United Kingdom.

    Science.gov (United States)

    Weller, Simon A; Bailey, Daniel; Matthews, Steven; Lumley, Sarah; Sweed, Angela; Ready, Derren; Eltringham, Gary; Richards, Jade; Vipond, Richard; Lukaszewski, Roman; Payne, Phillippa M; Aarons, Emma; Simpson, Andrew J; Hutley, Emma J; Brooks, Tim

    2016-01-01

    Rapid Ebola virus (EBOV) detection is crucial for appropriate patient management and care. The performance of the FilmArray BioThreat-E test (v2.5) using whole-blood samples was evaluated in Sierra Leone and the United Kingdom and was compared with results generated by a real-time Ebola Zaire PCR reference method. Samples were tested in diagnostic laboratories upon availability, included successive samples from individual patients, and were heat treated to facilitate EBOV inactivation prior to PCR. The BioThreat-E test had a sensitivity of 84% (confidence interval [CI], 64% to 95%) and a specificity of 89% (CI, 73% to 97%) in Sierra Leone (n = 60; 44 patients) and a sensitivity of 75% (CI, 19% to 99%) and a specificity of 100% (CI, 97% to 100%) in the United Kingdom (n = 108; 70 patients) compared to the reference real-time PCR. Statistical analysis (Fisher's exact test) indicated there was no significant difference between the methods at the 99% confidence level in either country. In 9 discrepant results (5 real-time PCR positives and BioThreat-E test negatives and 4 real-time PCR negatives and BioThreat-E test positives), the majority (n = 8) were obtained from samples with an observed or probable low viral load. The FilmArray BioThreat-E test (v2.5) therefore provides an attractive option for laboratories (either in austere field settings or in countries with an advanced technological infrastructure) which do not routinely offer an EBOV diagnostic capability.

  19. Simultaneous quantification of VX and its toxic metabolite in blood and plasma samples and its application for in vivo and in vitro toxicological studies.

    Science.gov (United States)

    Reiter, Georg; Mikler, John; Hill, Ira; Weatherby, Kendal; Thiermann, Horst; Worek, Franz

    2011-09-15

    The present study was initiated to develop a sensitive and highly selective method for the simultaneous quantification of the nerve agent VX (O-ethyl S-[2(diisopropylamino)ethyl] methylphosphonothioate) and its toxic metabolite (EA-2192) in blood and plasma samples in vivo and in vitro. For the quantitative detection of VX and EA-2192 the resolution was realized on a HYPERCARB HPLC phase. A specific procedure was developed to isolate both toxic analytes from blood and plasma samples. The limit of detection was 0.1 pg/ml and the absolute recovery of the overall sample preparation procedure was 74% for VX and 69% for EA-2192. After intravenous and percutaneous administration of a supralethal doses of VX in anaesthetised swine both VX and EA-2192 could be quantified over 540 min following exposure. This study is the first to verify the in vivo formation of the toxic metabolite EA-2192 after poisoning with the nerve agent VX. Further toxicokinetic and therapeutic studies are required in order to determine the impact of EA-2192 on the treatment of acute VX poisoning.

  20. Quality by Design-Applied Liquid Chromatography-Tandem Mass Spectrometry Determination of Enzalutamide Anti-Prostate Cancer Therapy Drug in Spiked Plasma Samples.

    Science.gov (United States)

    Sankar, Ask; Palani, Shanmugasundaram; Velayudham, Ravichandiran

    2017-01-01

    This research article presents the Quality by Design (QbD)-finalised conditions for a method that uses liquid chromatography-tandem mass spectrometry for the determination of concentration of enzalutamide (ENZ), an atypical anticancer drug, in a drug formulation and in spiked plasma samples. Critical process attributes (CPA) considered to be the influential parameters in separation, identification, and quantification processes by ultrahigh-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UHPLC-ESI-MS/MS) were organic content, buffer strength, pH modifier, flow rate, spray voltage, sheath gas, and auxiliary gas that alter critical analytical attributes, such as retention time (R1) and area (R2). These factors were evaluated first in a factorial design (Taguchi orthogonal array design) and then extensively in a central composite design (CCD) to zero-in on the mobile phase for the quantification of ENZ standard drug and along with its internal standard (ENZIS) in spiked plasma samples and in formulation. Pareto chart from initial factorial design (Taguchi orthogonal array design) model suggested which of the CPA factors should be given the weightage, that is, to be exhaustively analysed in the CCD and response surface analysis. The elaborated parameters proposed by World Health Organization were studied by method validation, ie, selectivity, linearity, accuracy, precision repeatability system-suitability tests, method robustness/ruggedness, sensitivity, and stability. The strategy followed gives an insight on the development of a robust QbD-compliant quantitative UHPLC-ESI-MS/MS method for ENZ drug containing plasma samples (spiked).

  1. Direct measurements of the energy flux due to chemical reactions at the surface of a silicon sample interacting with a SF6 plasma

    CERN Document Server

    Dussart, Remi; Pichon, Laurianne E; Bedra, Larbi; Semmar, Nadjib; Lefaucheux, Philippe; Mathias, Jacky; Tessier, Yves; 10.1063/1.2995988

    2008-01-01

    Energy exchanges due to chemical reactions between a silicon surface and a SF6 plasma were directly measured using a heat flux microsensor (HFM). The energy flux evolution was compared with those obtained when only few reactions occur at the surface to show the part of chemical reactions. At 800 W, the measured energy flux due to chemical reactions is estimated at about 7 W.cm\\^{-2} against 0.4 W.cm\\^{-2} for ion bombardment and other contributions. Time evolution of the HFM signal is also studied. The molar enthalpy of the reaction giving SiF4 molecules was evaluated and is consistent with values given in literature.

  2. A novel method for simultaneous determination of selected elements in dolomite and magnesia by Inductively Coupled Plasma Atomic Emission Spectroscopy with slurry sample introduction

    Science.gov (United States)

    Bok-Badura, Joanna; Jakóbik-Kolon, Agata; Turek, Marian; Szczerba, Jacek; Lemanowicz, Marcin; Karoń, Krzysztof

    2015-11-01

    The slurry nebulization ICP-AES method for simultaneous determination of selected elements in dolomite and magnesia was proposed. Based on the investigation results the optimal conditions for this analysis were as follows: particle size CRM 782-1 and High Purity Magnesia BCS-CRM 389/1 were analyzed. Student's t-test proved that there were no statistically significant differences between determined values and the certified ones. This proves that the slurry sample introduction into plasma in ICP-AES technique can be applied for simultaneous determination of elements in dolomite and magnesia.

  3. Determination of MKT-077, a novel antineoplastic agent, in plasma samples by high-performance liquid chromatography and its application to pharmacokinetics in rats.

    Science.gov (United States)

    Tatsuta, N; Suzuki, N; Koya, K; Kawakami, M; Shishido, T; Chen, L B

    1999-03-01

    A simple high-performance liquid chromatographic method was developed for determination of a novel antineoplastic agent MKT-077 in plasma. MKT-077 was extracted from 50 microl of plasma with acetonitrile containing 1 ml trifluoroacetic acid per liter. Chromatographic separation was achieved within 13.5 min using a reverse-phase Puresil C18 analytical column. A visible detector operated at 490 nm was used. The linearity of the calibration curve was obtained (r2 = 0.99986) over the analytical range of 10-500 ng/ml(-1). The intra- and inter-assay precision was in the range of 0.9-11.1 and 0.3-4.4%, respectively. The intra- and inter-assay bias ranged from -7.3 to 11.1% and from 0.4 to 11.6%, respectively. The utility of this assay was demonstrated after the administration of a single dose of MKT-077 to rats. The plasma elimination half-life of MKT-077 was 1.8-4 h.

  4. Determination of Acyclovir in Human Plasma Samples by HPLC Method with UV Detection: Application to Single-Dose Pharmacokinetic Study

    Directory of Open Access Journals (Sweden)

    Dragica Zendelovska

    2015-03-01

    CONCLUSION: Good precision, accuracy, simplicity, sensitivity and shorter time of analysis of the method makes it particularly useful for processing of multiple samples in a limited period of time for pharmacokinetic study of acyclovir.

  5. Development of a Rat Plasma and Brain Extracellular Fluid Pharmacokinetic Model for Bupropion and Hydroxybupropion Based on Microdialysis Sampling, and Application to Predict Human Brain Concentrations.

    Science.gov (United States)

    Cremers, Thomas I F H; Flik, Gunnar; Folgering, Joost H A; Rollema, Hans; Stratford, Robert E

    2016-05-01

    Administration of bupropion [(±)-2-(tert-butylamino)-1-(3-chlorophenyl)propan-1-one] and its preformed active metabolite, hydroxybupropion [(±)-1-(3-chlorophenyl)-2-[(1-hydroxy-2-methyl-2-propanyl)amino]-1-propanone], to rats with measurement of unbound concentrations by quantitative microdialysis sampling of plasma and brain extracellular fluid was used to develop a compartmental pharmacokinetics model to describe the blood-brain barrier transport of both substances. The population model revealed rapid equilibration of both entities across the blood-brain barrier, with resultant steady-state brain extracellular fluid/plasma unbound concentration ratio estimates of 1.9 and 1.7 for bupropion and hydroxybupropion, respectively, which is thus indicative of a net uptake asymmetry. An overshoot of the brain extracellular fluid/plasma unbound concentration ratio at early time points was observed with bupropion; this was modeled as a time-dependent uptake clearance of the drug across the blood-brain barrier. Translation of the model was used to predict bupropion and hydroxybupropion exposure in human brain extracellular fluid after twice-daily administration of 150 mg bupropion. Predicted concentrations indicate that preferential inhibition of the dopamine and norepinephrine transporters by the metabolite, with little to no contribution by bupropion, would be expected at this therapeutic dose. Therefore, these results extend nuclear imaging studies on dopamine transporter occupancy and suggest that inhibition of both transporters contributes significantly to bupropion's therapeutic efficacy.

  6. Manual versus automated blood sampling

    DEFF Research Database (Denmark)

    Teilmann, A C; Kalliokoski, Otto; Sørensen, Dorte B

    2014-01-01

    Facial vein (cheek blood) and caudal vein (tail blood) phlebotomy are two commonly used techniques for obtaining blood samples from laboratory mice, while automated blood sampling through a permanent catheter is a relatively new technique in mice. The present study compared physiological parameters......, glucocorticoid dynamics as well as the behavior of mice sampled repeatedly for 24 h by cheek blood, tail blood or automated blood sampling from the carotid artery. Mice subjected to cheek blood sampling lost significantly more body weight, had elevated levels of plasma corticosterone, excreted more fecal...... corticosterone metabolites, and expressed more anxious behavior than did the mice of the other groups. Plasma corticosterone levels of mice subjected to tail blood sampling were also elevated, although less significantly. Mice subjected to automated blood sampling were less affected with regard to the parameters...

  7. An example of genetically distinct HIV type 1 variants in cerebrospinal fluid and plasma during suppressive therapy

    OpenAIRE

    Dahl, V.; Gisslen, M.; Hagberg, L.; Peterson, J.; Shao, W.; Spudich, S.; Price, RW; Palmer, S.

    2014-01-01

    We sequenced the genome of human immunodeficiency virus type 1 (HIV-1) recovered from 70 cerebrospinal fluid (CSF) specimens and 29 plasma samples and corresponding samples obtained before treatment initiation from 17 subjects receiving suppressive therapy. More CSF sequences than plasma sequences were hypermutants. We determined CSF sequences and plasma sequences in specimens obtained from 2 subjects after treatment initiation. In one subject, we found genetically distinct CSF and plasma seq...

  8. Implementation of suitable flow injection/sequential-sample separation/preconcentration schemes for determination of trace metal concentrations using detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Wang, Jianhua

    2002-01-01

    Various preconditioning procedures encomprising appropriate separation/preconcentration schemes in order to obtain optimal sensitivity and selectivity characteristics when using electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are pres...

  9. Determination of trace rare earth elements in coal fly ash and atmospheric particulates by electrothermal vaporization inductively coupled plasma mass spectrometry with slurry sampling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuefei [Department of Chemistry, Wuhan University, Wuhan, Hubei Province 430072 (China); Jiang Zucheng [Department of Chemistry, Wuhan University, Wuhan, Hubei Province 430072 (China); He Man [Department of Chemistry, Wuhan University, Wuhan, Hubei Province 430072 (China); Hu Bin [Department of Chemistry, Wuhan University, Wuhan, Hubei Province 430072 (China)]. E-mail: binhu@whu.edu.cn

    2007-07-15

    A method of fluorination assisted electrothermal vaporization (FETV)-ICP-MS with polytetrafluoroethylene as fluorinating reagent was developed for the direct determination of trace rare earth elements (REEs) in coal fly ash and atmospheric particulates. Under the optimal conditions, the detection limits for REEs were 0.1 pg m{sup -3}(Eu) to 6.7 pg m{sup -3}(Nd) with the precisions of 4.1%(Yb) to 10%(La) (c = 1 {mu}g L{sup -1}, n = 9). The proposed method was applied to determine trace REEs in coal fly ash, airborne particulates and NIES SRM No. 8 Vehicle Exhaust Particulates. It was found that the determined values for Y, La, Pr and Nd obtained by slurry sampling FETV-ICP-MS with external calibration coincided with that obtained by pneumatic nebulization (PN)-ICP-MS and slurry sampling FETV-ICP-MS with standard addition. However, the determined values for Ce and Sm obtained by slurry sampling FETV-ICP-MS with external calibration were lower than that obtained by PN-ICP-MS and slurry sampling FETV-ICP-MS with standard addition. - A new method for direct determination of trace rare earth elements in coal fly ash and atmospheric particulates by fluorination ETV-ICP-MS with slurry sampling.

  10. Ultra-trace determination of plutonium in marine samples using multi-collector inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, Patric, E-mail: patriclindahl@yahoo.com [Marine Environment Research Department, Korea Ocean Research and Development Institute, 1270 Sadong, Ansan 426-744 (Korea, Republic of); School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom); Keith-Roach, Miranda; Worsfold, Paul [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom); Choi, Min-Seok; Shin, Hyung-Seon [Division of Earth and Environmental Science, Korea Basic Science Institute, 113 Gwahangno, Yusung-gu, Daejon 305-333 (Korea, Republic of); Lee, Sang-Hoon [Marine Geology and Geophysics Laboratory, Korea Ocean Research and Development Institute, 1270 Sadong, Ansan 426-744 (Korea, Republic of)

    2010-06-25

    Sources of plutonium isotopes to the marine environment are well defined, both spatially and temporally, which makes Pu a potential tracer for oceanic processes. This paper presents the selection, optimisation and validation of a sample preparation method for the ultra-trace determination of Pu isotopes ({sup 240}Pu and {sup 239}Pu) in marine samples by multi-collector (MC) ICP-MS. The method was optimised for the removal of the interference from {sup 238}U and the chemical recovery of Pu. Comparison of various separation strategies using AG1-X8, TEVA, TRU, and UTEVA resins to determine Pu in marine calcium carbonate samples is reported. A combination of anion-exchange (AG1-X8) and extraction chromatography (UTEVA/TRU) was the most suitable, with a radiochemical Pu yield of 87 {+-} 5% and a U decontamination factor of 1.2 x 10{sup 4}. Validation of the method was accomplished by determining Pu in various IAEA certified marine reference materials. The estimated MC-ICP-MS instrumental limit of detection for {sup 239}Pu and {sup 240}Pu was 0.02 fg mL{sup -1}, with an absolute limit of quantification of 0.11 fg. The proposed method allows the determination of ultra-trace Pu, at femtogram levels, in small size marine samples (e.g., 0.6-2.0 g coral or 15-20 L seawater). Finally, the analytical method was applied to determining historical records of the Pu signature in coral samples from the tropical Northwest Pacific and {sup 239+240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios in seawater samples as part of the 2008 GEOTRACES intercalibration exercise.

  11. Laser ablation-inductively coupled plasma-mass spectrometry: Examinations of the origins of polyatomic ions and advances in the sampling of particulates

    Energy Technology Data Exchange (ETDEWEB)

    Witte, Travis [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    This dissertation provides a general introduction to Inductively coupled plasma-mass spectrometry (ICP-MS) and laser ablation (LA) sampling, with an examination of analytical challenges in the employment of this technique. It discusses the origin of metal oxide ions (MO+) in LA-ICP-MS, as well as the effect of introducing helium and nitrogen to the aerosol gas flow on the formation of these polyatomic interferences. It extends the study of polyatomic ions in LA-ICP-MS to metal argide (MAr+) species, an additional source of possible significant interferences in the spectrum. It describes the application of fs-LA-ICP-MS to the determination of uranium isotope ratios in particulate samples.

  12. Rapid Determination of Plutonium Isotopes in Environmental Samples Using Sequential Injection Extraction Chromatography and Detection by Inductively Coupled Plasma Mass Spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2009-01-01

    by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example......This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed....... The analytical results of Pu isotopes in the reference materials showed good agreement with the certified or reference values at the 0.05 significance level. Chemical yields of Pu ranged from 80 to 105%, and the decontamination factors for uranium, thorium, mercury and lead were all above 104. The duration...

  13. Implementation of suitable flow injection/sequential-sample separation/preconcentration schemes for determination of trace metal concentrations using detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Wang, Jianhua

    2002-01-01

    Various preconditioning procedures encomprising appropriate separation/preconcentration schemes in order to obtain optimal sensitivity and selectivity characteristics when using electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are pres......Various preconditioning procedures encomprising appropriate separation/preconcentration schemes in order to obtain optimal sensitivity and selectivity characteristics when using electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS...... prior to detection are effected in a microconduit placed on top of an SI selection valve....

  14. Solid Matrix Transformation and Tracer Addition using Molten Ammonium Bifluoride Salt as a Sample Preparation Method for Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Gonzalez, Jhanis J.; O' Hara, Matthew J.; Kellogg, Cynthia M.; Morrison, Samuel S.; Koppenaal, David W.; Chan, George C.; Mao, Xianglei; Zorba, Vassilia; Russo, Richard

    2017-09-08

    Laser ablation (LA) is a means of sample introduction to inductively coupled plasma (ICP) mass spectrometry (MS) that avoids acid dissolution and chemical separation steps conventionally associated with solid sample analysis. At the same time, certain features of LA-ICP-MS are often mentioned in critical reviews including solid matrix variability and its influence on the ablation process, matrix dependent elemental fractionation, lack of matrix matched standards for external calibration, and limitations to internal calibration because it is challenging to add and distribute spikes into solid samples. In this paper we introduce the concept of a synergistic minimal sample preparation method that is used in combination with LA-ICP-MS as a means to overcome these limitations. The aim of this minimal sample preparation procedure is to reactively transform the original matrix to a more consistent matrix for LA-based analysis, thus reducing the effects of matrix variability, while enabling the addition of tracers. In conjunction with ICP-MS, we call this MTR-LA-ICP-MS, where MTR is derived from matrix transformation including the option to add tracers

  15. Polymer monolithic capillary microextraction on-line coupled with inductively coupled plasma-mass spectrometry for the determination of trace Au and Pd in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaolan; He, Man; Chen, Beibei; Hu, Bin, E-mail: binhu@whu.edu.cn

    2014-11-01

    A novel method based on on-line polymer monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace Au and Pd in biological samples. For this purpose, poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was prepared and functionalized with mercapto groups. The prepared monolith exhibited good selectivity to Au and Pd, and good resistance to strong acid with a long life span. Factors affecting the extraction efficiency of CME, such as sample acidity, sample flow rate, eluent conditions and coexisting ion interference were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) were 5.9 ng L{sup −1} for Au and 8.3 ng L{sup −1} for Pd, and the relative standard deviations (RSDs, c = 50 ng L{sup −1}, n = 7) were 6.5% for Au and 1.1% for Pd, respectively. The developed method was successfully applied to the determination of Au and Pd in human urine and serum samples with the recovery in the range of 84–118% for spiked samples. The developed on-line polymer monolithic CME-ICP-MS method has the advantages of rapidity, simplicity, low sample/reagent consumption, high sensitivity and is suitable for the determination of trace Au and Pd in biological samples with limited amount available and complex matrix. - Highlights: • An on-line CME-ICP-MS method was developed for Au and Pd analysis in human fluids. • Poly(GMA-EDMA-SH) monolith exhibited good selectivity for Au/Pd and acid-resistance. • The method is rapid, simple, and sensitive with low sample/reagents consumption.

  16. The Metabolic Syndrome, Inflammation, and Colorectal Cancer Risk: An Evaluation of Large Panels of Plasma Protein Markers Using Repeated, Prediagnostic Samples

    Directory of Open Access Journals (Sweden)

    Sophia Harlid

    2017-01-01

    Full Text Available Metabolic syndrome (MetS, a set of metabolic risk factors including obesity, dysglycemia, and dyslipidemia, is associated with increased colorectal cancer (CRC risk. A putative biological mechanism is chronic, low-grade inflammation, both a feature of MetS and a CRC risk factor. However, excess body fat also induces a proinflammatory state and increases CRC risk. In order to explore the relationship between MetS, body size, inflammation, and CRC, we studied large panels of inflammatory and cancer biomarkers. We included 138 participants from the Västerbotten Intervention Programme with repeated sampling occasions, 10 years apart. Plasma samples were analyzed for 178 protein markers by proximity extension assay. To identify associations between plasma protein levels and MetS components, linear mixed models were fitted for each protein. Twelve proteins were associated with at least one MetS component, six of which were associated with MetS score. MetS alone was not related to any protein. Instead, BMI displayed by far the strongest associations with the biomarkers. One of the 12 MetS score-related proteins (FGF-21, also associated with BMI, was associated with an increased CRC risk (OR 1.71, 95% CI 1.19–2.47. We conclude that overweight and obesity, acting through both inflammation and other mechanisms, likely explain the MetS-CRC connection.

  17. Simultaneous determination of selected eicosanoids by reversed-phase HPLC method using fluorescence detection and application to rat and human plasma, and rat heart and kidney samples.

    Science.gov (United States)

    Aghazadeh-Habashi, Ali; Asghar, Waheed; Jamali, Fakhreddin

    2015-06-10

    Eicosanoids are biologically active lipid-derived oxidative metabolites of arachidonic acid. We, herein, present an improved sensitive, selective and robust high performance liquid chromatography (HPLC)-fluorescence assay for simultaneous quantification of eicosanoids in human plasma and rat tissues. Aliquots of 200 μL of plasma or 30 mg of heart or kidney tissues were spiked with 16-hydroxydecanoic acid as internal standard, and extracted with anhydrous acetonitrile using solid phase cartridges. The eluted samples were dried, reconstituted in anhydrous acetonitrile and labeled with 2-(2,3-naphthalimino)ethyl-trifluoromethanesulphonate in the presence of saturated potassium fluoride solution in anhydrous acetonitrile and N,N-diiospropylethylamine as catalyst. The derivatized eicosanoids were extracted with anhydrous acetonitrile using solid phase cartridges. Chromatographic separation was achieved on a C18 reversed phase column using gradient mobile phase of 0.05% of formic acid:acetonitrile:water at 0.8 mL/min flow rate. The analytes were detected at excitation and emission wavelength of 260 and 396 nm, respectively. The assay was linear (r(2)≥ 0.98) in the concentration range of 0.01-2.5 μg/mL. The intra-day and inter-day coefficients variation was less than 19.8%. Using this assay, we were able to quantify arachidonic acid metabolites simultaneously in human and rat biological samples.

  18. Quantification of 3-n-butylphthalide in beagle plasma samples by supercritical fluid chromatography with triple quadruple mass spectrometry and its application to an oral bioavailability study.

    Science.gov (United States)

    Li, Yun; Zhao, Longshan; Li, Xiaoting; Guo, Bei; Zhao, Juanhang; Wang, Xianglin; Zhang, Tianhong

    2015-02-01

    A high-throughput, rapid, sensitive, environmentally friendly, and economical supercritical fluid chromatography with triple quadruple mass spectrometry method was established and validated for the first time to determine a cerebral stroke treatment drug named 3-n-butylphthalide in dog plasma. Plasma samples were prepared by protein precipitation with methanol and the analytes were eluted on an ACQUITY UPC(2TM) HSS-C(18) SB column (3 × 100 mm, 1.8 μm) maintained at 50°C. The mobile phase comprised supercritical carbon dioxide/methanol (90:10, v/v) at a flow rate of 1.5 mL/min, the compensation solvent was methanol at a flow rate of 0.2 mL/min and the total run time was 1.5 min per sample. The detection was carried out on a tandem mass spectrometer with an electrospray ionization source. Calibration curves were linear over the concentration range of 1.02-1021.00 ng/mL (r(2) ≥ 0.993) with the lower limit of quantification of 1.02 ng/mL. The intra- and inter-day precision values were below 15% and the accuracy was from 97.90 to 103.70% at all quality control levels. The method was suitable for a pharmacokinetic study of 3-n-butylphthalide in beagle dogs.

  19. On-Line Organic Solvent Field Enhanced Sample Injection in Capillary Zone Electrophoresis for Analysis of Quetiapine in Beagle Dog Plasma.

    Science.gov (United States)

    Cao, Yuqing; Wen, Jun; Zhou, Tingting; Fan, Guorong

    2016-01-21

    A rapid and sensitive capillary zone electrophoresis (CZE) method with field enhanced sample injection (FESI) was developed and validated for the determination of quetiapine fumarate in beagle dog plasma, with a sample pretreatment by LLE in 96-well deep format plate. The optimum separation was carried out in an uncoated 31.2 cm × 75 μm fused-silica capillary with an applied voltage of 13 kV. The electrophoretic analysis was performed by 50 mM phosphate at pH 2.5. The detection wavelength was 210 nm. Under these optimized conditions, FESI with acetonitrile enhanced the sensitivity of quetiapine about 40-50 folds in total. The method was suitably validated with respect to stability, specificity, linearity, lower limit of quantitation, accuracy, precision and extraction recovery. Using mirtazapine as an internal standard (100 ng/mL), the response of quetiapine was linear over the range of 1-1000 ng/mL. The lower limit of quantification was 1 ng/mL. The intra- and inter-day precisions for the assay were within 4.8% and 12.7%, respectively. The method represents the first application of FESI-CZE to the analysis of quetiapine fumarate in beagle dog plasma after oral administration.

  20. On-Line Organic Solvent Field Enhanced Sample Injection in Capillary Zone Electrophoresis for Analysis of Quetiapine in Beagle Dog Plasma

    Directory of Open Access Journals (Sweden)

    Yuqing Cao

    2016-01-01

    Full Text Available A rapid and sensitive capillary zone electrophoresis (CZE method with field enhanced sample injection (FESI was developed and validated for the determination of quetiapine fumarate in beagle dog plasma, with a sample pretreatment by LLE in 96-well deep format plate. The optimum separation was carried out in an uncoated 31.2 cm × 75 μm fused-silica capillary with an applied voltage of 13 kV. The electrophoretic analysis was performed by 50 mM phosphate at pH 2.5. The detection wavelength was 210 nm. Under these optimized conditions, FESI with acetonitrile enhanced the sensitivity of quetiapine about 40–50 folds in total. The method was suitably validated with respect to stability, specificity, linearity, lower limit of quantitation, accuracy, precision and extraction recovery. Using mirtazapine as an internal standard (100 ng/mL, the response of quetiapine was linear over the range of 1–1000 ng/mL. The lower limit of quantification was 1 ng/mL. The intra- and inter-day precisions for the assay were within 4.8% and 12.7%, respectively. The method represents the first application of FESI-CZE to the analysis of quetiapine fumarate in beagle dog plasma after oral administration.

  1. Quantitative analysis of deuterium in zircaloy using double-pulse laser-induced breakdown spectrometry (LIBS) and helium gas plasma without a sample chamber.

    Science.gov (United States)

    Suyanto, H; Lie, Z S; Niki, H; Kagawa, K; Fukumoto, K; Rinda, Hedwig; Abdulmadjid, S N; Marpaung, A M; Pardede, M; Suliyanti, M M; Hidayah, A N; Jobiliong, E; Lie, T J; Tjia, M O; Kurniawan, K H

    2012-03-06

    A crucial safety measure to be strictly observed in the operation of heavy-water nuclear power plants is the mandatory regular inspection of the concentration of deuterium penetrated into the zircaloy fuel vessels. The existing standard method requires a tedious, destructive, and costly sample preparation process involving the removal of the remaining fuel in the vessel and melting away part of the zircaloy pipe. An alternative method of orthogonal dual-pulse laser-induced breakdown spectrometry (LIBS) is proposed by employing flowing atmospheric helium gas without the use of a sample chamber. The special setup of ps and ns laser systems, operated for the separate ablation of the sample target and the generation of helium gas plasma, respectively, with properly controlled relative timing, has succeeded in producing the desired sharp D I 656.10 nm emission line with effective suppression of the interfering H I 656.28 nm emission by operating the ps ablation laser at very low output energy of 26 mJ and 1 μs ahead of the helium plasma generation. Under this optimal experimental condition, a linear calibration line is attained with practically zero intercept and a 20 μg/g detection limit for D analysis of zircaloy sample while creating a crater only 10 μm in diameter. Therefore, this method promises its potential application for the practical, in situ, and virtually nondestructive quantitative microarea analysis of D, thereby supporting the more-efficient operation and maintenance of heavy-water nuclear power plants. Furthermore, it will also meet the anticipated needs of future nuclear fusion power plants, as well as other important fields of application in the foreseeable future.

  2. WISECONDOR: detection of fetal aberrations from shallow sequencing maternal plasma based on a within-sample comparison scheme

    NARCIS (Netherlands)

    Straver, R.; Sistermans, E.A.; Holstege, H.; Visser, A.; Oudejans, C.B.M.; Reinders, M.J.T.

    2013-01-01

    Genetic disorders can be detected by prenatal diagnosis using Chorionic Villus Sampling, but the 1:100 chance to result in miscarriage restricts the use to fetuses that are suspected to have an aberration. Detection of trisomy 21 cases noninvasively is now possible owing to the upswing of next-gener

  3. Sensitive spectrofluorimetric methods for determination of ethopabate and amprolium hydrochloride in chicken plasma and their residues in food samples.

    Science.gov (United States)

    El-Kosasy, Amira M; Hussein, Lobna A; Magdy, N; Abbas, Mahmoud M

    2015-01-01

    Two sensitive and selective spectrofluorimetric methods are proposed to determine ethopabate (ETH) and amprolium hydrochloride (AMP). First derivative synchronous spectrofluorimetry determines the natively fluorescent ethopabate at 288 nm in presence of amprolium hydrochloride which is a non fluorescent quaternary compound with average recovery 100.54±0.721 over a concentration range of 0.01-0.8 μg/mL. Limits of detection (LOD) and quantification (LOQ) are 0.002 and 0.007 μg/mL, respectively. The second method is direct synchronous spectrofluorimetry for determining amprolium hydrochloride at 362 nm after a reaction with 5% NaOH and 0.08% potassium ferricyanide that is optimized by a two-level factorial design. This method is linear over a concentration range of 0.01-0.65 μg/mL with average recovery 99.4±1.28. Limits of detection (LOD) and quantification (LOQ) are 0.002 and 0.006 μg/mL, respectively. The proposed methods are found to be valid and applicable for the analysis of ETH and AMP in their veterinary formulation. They are successfully applied to determine the studied drugs in chicken plasma and their residues in chicken muscle, liver, egg and chicken-based baby food product with recoveries in the ranges of 95.71-108.73% and 97.36-111.89% and for ETH and AMP, respectively.

  4. Total sulfur determination in gasoline, kerosene and diesel fuel using inductively coupled plasma optical emission spectrometry after direct sample introduction as detergent emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Santelli, Ricardo Erthal [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro Sao Joao Batista s/n, Centro, Niteroi/RJ, 24020-150 (Brazil)], E-mail: santelli@geoq.uff.br; Padua Oliveira, Eliane [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro Sao Joao Batista s/n, Centro, Niteroi/RJ, 24020-150 (Brazil); Departamento de Engenharia Quimica e de Petroleo, Universidade Federal Fluminense, Rua Passos da Patria 156, Sao Domingos, Niteroi/RJ, 24210-230 (Brazil); Batista de Carvalho, Maria de Fatima [Centro de Pesquisas e Desenvolvimento da PETROBRAS, Avaliacao e Monitoramento Ambiental, Av. Horacio Macedo, 950, Cidade Universitaria, Rio de Janeiro/RJ, 21941-598 (Brazil); Almeida Bezerra, Marcos [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro Sao Joao Batista s/n, Centro, Niteroi/RJ, 24020-150 (Brazil); Universidade Estadual do Sudoeste da Bahia, Laboratorio de Quimica Analitica, Rua Jose Moreira Sobrinho s/n, Jequiezinho, Jequie/BA, 45206-190 (Brazil); Soares Freire, Aline [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro Sao Joao Batista s/n, Centro, Niteroi/RJ, 24020-150 (Brazil)

    2008-07-15

    Herein, we present the development of a procedure for the determination of total sulfur in petroleum-derived products (gasoline, kerosene and diesel fuel) employing inductively coupled plasma optical emission spectrometry (ICP OES). For this procedure, samples were prepared as emulsions that were made using concentrated nitric acid, Triton X-100, sample, and ultra pure water in proportions of 5/10/7/78% (v/v), respectively. Sample volumes were weighed because of the density differences, and oxygen was added to the sheat gas entrance of the ICP OES in order to decrease carbon deposition in the torch and to minimize background effects. A Doehlert design was applied as an experimental matrix to investigate the flow ratios of argon (sheat and plasma gas) and oxygen in relation to the signal-to-background ratio. A comparative study among the slopes of the analytical curves built in aqueous media, surfactant/HNO{sub 3}, and by spike addition for several sample emulsions indicates that a unique solution of surfactant in acidic media can be employed to perform the external calibration for analysis of the emulsions. The developed procedure allows for the determination of the total sulfur content in petroleum derivatives with a limit of detection (LOD) and limit of quantification (LOQ) of 0.72 and 2.4 {mu}g g{sup -1}, respectively. Precision values, expressed as the relative standard deviations (% RSD, n = 10) for 12 and 400 {mu}g g{sup -1}, were 2.2% and 1.3%, respectively. The proposed procedure was applied toward the determination of total sulfur in samples of gasoline, kerosene, and diesel fuel commercialized in the city of Niteroi/RJ, Brazil. The accuracy of the proposed method was evaluated by the determination of the total sulfur in three different standard reference materials (SRM): NIST 2723a (sulfur in diesel fuel oil), NIST 1616b (sulfur in kerosene), and NIST 2298 (sulfur in gasoline). The data indicate that the methodology can be successfully applied to these

  5. Determination of trace rare earth elements in coal fly ash and atmospheric particulates by electrothermal vaporization inductively coupled plasma mass spectrometry with slurry sampling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.F.; Jiang, Z.C.; He, M.; Hu, B. [Wuhan University, Wuhan (China). Dept. of Chemistry

    2007-07-15

    A method of fluorination assisted electrothermal vaporization (FETV)-ICP