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Sample records for haematology oxygen transport

  1. Artificial oxygen transport protein

    SciTech Connect

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  2. Atomic transport of oxygen

    SciTech Connect

    Routbort, J.L.; Tomlins, G.W.

    1994-06-15

    Atomic transport of oxygen in nonstoichiometric oxides is an extremely important topic which overlaps science and technology. In many cases the diffusion of oxygen controls sintering, grain growth, and creep. High oxygen diffusivity is critical for efficient operation of many fuel cells. Additionally, oxygen diffusivities are an essential ingredient in any point defect model. Secondary Ion Mass Spectrometry (SIMS) is the most accurate modern technique to measure oxygen tracer diffusion. This paper briefly reviews the principles and applications of SIMS for the measurement of oxygen transport. Case studies are taken from recent work on ZnO and some high-temperature superconductors.

  3. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2003-01-01

    In the present quarter, the possibility of using a more complex interfacial engineering approach to the development of reliable and stable oxygen transport perovskite ceramic membranes/metal seals is discussed. Experiments are presented and ceramic/metal interactions are characterized. Crack growth and fracture toughness of the membrane in the reducing conditions are also discussed. Future work regarding this approach is proposed are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

  4. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  5. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2002-04-01

    This report covers the following tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints; Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability; Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres; Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures; Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability; and Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  6. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; N. Nagabhushana; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-02-01

    under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  7. Oxygen Transport Membranes

    SciTech Connect

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  8. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2001-12-01

    Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  9. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-05-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report

  10. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-10-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, Moessbauer spectroscopy was used to study the local environmentals of LSFT with various level of oxygen deficiency. Ionic valence state, magnetic interaction and influence of Ti on superexchange are discussed Stable crack growth studies on Dense OTM bars provided by Praxair were done at elevated temperature, pressure and elevated conditions. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. The initial measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Neutron diffraction measurements of the same composition are in agreement with both the stoichiometry and the kinetic behavior observed in coulometric titration measurements. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The COCO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  11. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; N. Nagabhushana

    2003-08-07

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/ Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Existing facilities were modified for evaluation of environmental assisted slow crack growth and creep in flexural mode. Processing of perovskites of LSC, LSF and LSCF composition were continued for evaluation of mechanical properties as a function of environment. These studies in parallel to those on the LSFCO composition is expect to yield important information on questions such as the role of cation segregation and the stability of the perovskite structure on crack initiation vs. crack growth. Studies have been continued on the La{sub 1-x}Sr{sub x}FeO{sub 3-d} composition using neutron diffraction and TGA studies. A transition from p-type to n-type of conductor was observed at relative low pO{sub 2}, at which the majority carriers changed from the holes to electrons because of the valence state decreases in Fe due to the further loss of oxygen. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport. Data obtained at 850 C show that the stoichiometry in La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3-x} vary from {approx}2.85 to 2.6 over the pressure range studied. From the stoichiometry a lower limit of 2.6 corresponding to the reduction of all Fe{sup 4+} to Fe{sup 3+} and no reduction of Cr{sup 3+} is expected.

  12. Oxygen consumption and haematology of juvenile shortnose sturgeon Acipenser brevirostrum during an acute 24 h saltwater challenge.

    PubMed

    Penny, F M; Kieffer, J D

    2014-04-01

    This study focused on the acute physiological responses to saltwater exposure in juvenile shortnose sturgeon Acipenser brevirostrum. In two separate laboratory experiments, 2 year-old A. brevirostrum were exposed to either full (32) or half-strength (16) seawater for up to 24 h. First, oxygen consumption rates were used to estimate the metabolic costs over 24 h. Secondly, blood and muscle samples were analysed at 6, 12 and 24 h for water loss, various measures of osmoregulatory status (plasma osmolality and ions) and other standard haematological variables. Juveniles exposed to full-strength seawater showed significant decreases in oxygen consumption rates during the 24 h exposure. Furthermore, seawater-exposed fish had significantly increased plasma osmolality, ions (Na(+) and Cl(-)) and a 17% decrease in total wet mass over the 24 h exposure period. To a lesser extent, increases in osmolality, ions and mass loss were observed in fish exposed to half-strength seawater but no changes to oxygen consumption. Cortisol was also significantly increased in fish exposed to full-strength seawater. While plasma protein was elevated following 24 h in full-strength seawater, haemoglobin, haematocrit and plasma glucose levels did not change with increased salinity. These results imply an inability of juvenile A. brevirostrum to regulate water and ions in full-strength seawater within 24 h. Nonetheless, no mortality occurred in any exposure, suggesting that juvenile A. brevirostrum can tolerate short periods in saline environments. PMID:24628001

  13. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-05-01

    the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  14. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-08-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

  15. Haematological rather than skeletal muscle adaptations contribute to the increase in peak oxygen uptake induced by moderate endurance training.

    PubMed

    Montero, David; Cathomen, Adrian; Jacobs, Robert A; Flück, Daniela; de Leur, Jeroen; Keiser, Stefanie; Bonne, Thomas; Kirk, Niels; Lundby, Anne-Kristine; Lundby, Carsten

    2015-10-15

    It remains unclear whether improvements in peak oxygen uptake (V̇(O2peak)) following endurance training (ET) are primarily determined by central and/or peripheral adaptations. Herein, we tested the hypothesis that the improvement in V̇(O2peak) following 6 weeks of ET is mainly determined by haematological rather than skeletal muscle adaptations. Sixteen untrained healthy male volunteers (age = 25 ± 4 years, V̇(O2peak) = 3.5 ± 0.5 l min(-1)) underwent supervised ET (6 weeks, 3-4 sessions per week). V̇(O2peak), peak cardiac output (Q̇(peak)), haemoglobin mass (Hb(mass)) and blood volumes were assessed prior to and following ET. Skeletal muscle biopsies were analysed for mitochondrial volume density (Mito(VD)), capillarity, fibre types and respiratory capacity (OXPHOS). After the post-ET assessment, red blood cell volume (RBCV) was re-established at the pre-ET level by phlebotomy and V̇(O2peak) and Q̇(peak) were measured again. We speculated that the contribution of skeletal muscle adaptations to the ET-induced increase in V̇(O2peak) would be revealed when controlling for haematological adaptations. V̇(O2peak) and Q̇(peak) were increased (P < 0.05) following ET (9 ± 8 and 7 ± 6%, respectively) and decreased (P < 0.05) after phlebotomy (-7 ± 7 and -10 ± 7%). RBCV, plasma volume and Hb(mass) all increased (P < 0.05) after ET (8 ± 4, 4 ± 6 and 6 ± 5%). As for skeletal muscle adaptations, capillary-to-fibre ratio and total Mito(VD) increased (P < 0.05) following ET (18 ± 16 and 43 ± 30%), but OXPHOS remained unaltered. Through stepwise multiple regression analysis, Q̇(peak), RBCV and Hb(mass) were found to be independent predictors of V̇(O2peak). In conclusion, the improvement in V̇(O2peak) following 6 weeks of ET is primarily attributed to increases in Q̇(peak) and oxygen-carrying capacity of blood in untrained healthy young subjects. PMID:26282186

  16. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; T. Nithyanantham

    2006-12-31

    Ti doping on La{sub 1-x}Sr{sub x}FeO{sub 3-{delta}} (LSF) tends to increase the oxygen equilibration kinetics of LSF in lower oxygen activity environment because of the high valence state of Ti. However, the addition of Ti decreases the total conductivity because the acceptor ([Sr{prime}{sub La}]) is compensated by the donor ([Ti{sub Fe}{sup {sm_bullet}}]) which decreases the carrier concentration. The properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (LSFT, x = 0.45) have been experimentally and theoretically investigated to elucidate (1) the dependence of oxygen occupancy and electrochemical properties on temperature and oxygen activity by thermogravimetric analysis (TGA) and (2) the electrical conductivity and carrier concentration by Seebeck coefficient and electrical measurements. In the present study, dual phase (La{sub 0.2}Sr{sub 0.8}Fe{sub 0.6}Ti{sub 0.4}O{sub 3-{delta}}/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}}) membranes have been evaluated for structural properties such as hardness, fracture toughness and flexural strength. The effect of high temperature and slightly reducing atmosphere on the structural properties of the membranes was studied. The flexural strength of the membrane decreases upon exposure to slightly reducing conditions at 1000 C. The as-received and post-fractured membranes were characterized using XRD, SEM and TG-DTA to understand the fracture mechanisms. Changes in structural properties of the composite were sought to be correlated with the physiochemical features of the two-phases. We have reviewed the electrical conductivity data and stoichiometry data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} some of which was reported previously. Electrical conductivity data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCrF) were obtained in the temperature range, 752 {approx} 1055 C and in the pO{sub 2} range, 10{sup -18} {approx} 0.5 atm. The slope of the plot of log {sigma} vs

  17. Composite oxygen transport membrane

    SciTech Connect

    Christie, Gervase Maxwell; Lane, Jonathan A.

    2014-08-05

    A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

  18. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2002-01-01

    Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals.

  19. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; W.B. Yelon; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-02-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and initial studies on newer composition of Ti doped LSF. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. In addition, studies were also begun to obtain reliable estimates of fracture toughness and stable crack growth in specific environments. Newer composition of Ti doped LSF membranes were characterized by neutron diffraction analysis. Quench studies indicated an apparent correlation between the unit cell volume and oxygen occupancy. The studies however, indicated an anomaly of increasing Fe/Ti ratio with change in heat treatment. Ti doped LSF was also characterized for stoichiometry as a function of temp and pO{sub 2}. The non stoichiometry parameter {delta} was observed to increase almost linearly on lowering pO{sub 2} until a ideal stoichiometric composition of {delta} = 0.175 was approached.

  20. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2003-01-01

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.

  1. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-11-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

  2. Composite oxygen ion transport element

    DOEpatents

    Chen, Jack C.; Besecker, Charles J.; Chen, Hancun; Robinson, Earil T.

    2007-06-12

    A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo.sub.5Si.sub.3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

  3. Catalyst containing oxygen transport membrane

    DOEpatents

    Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

    2012-12-04

    A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

  4. Oxygen transport and exchange in oxide ceramics

    NASA Astrophysics Data System (ADS)

    Steele, B. C. H.

    1994-04-01

    Oxygen transport in most oxide ceramics incorporated in solid oxide fuel cells (SOFC) involves the movement of oxygen ion vacancies. It is the relative magnitude of oxygen ion vacancy and electronic charge carrier concentrations and mobilities which determines whether oxide materials can function as effective electrolyte or electrode components. Examination of relevant data suggests that zirconia- and ceria-based electrolytes are unlikely to be replaced in SOFC systems operating in the temperature range 450-950 C. Oxygen ion vacancies are also involved in the cathodic reduction of oxygen and influence the magnitude of the associated exchange current density which can be measured by isotopic oxygen exchange measurements. Oxygen vacancy concentrations are also implicated in thermal expansion coefficient values and chemical stability considerations. It follows that optimisation of the cathode composition requires many conflicting requirements to be satisfied. However for operation at 800 C, electrolyte, electrode and bipolar plate materials are available to ensure power densities approaching 0.5 W sq cm. In contrast, direct methanol SOFC systems operating at 500 C necessitate the development of alternative electrode materials. The successful exploitation of our knowledge about oxygen ion vacancy transport in ceramic oxides has now stimulated research into the role of protons in oxide lattices, and it is postulated that protonic/hydroxyl ion transport could be important in the development of alternative anode components.

  5. Cardiac remodelling, blood chemistry, haematology and oxygen consumption of Atlantic cod, Gadus morhua L., induced by experimental haemolytic anaemia with phenylhydrazine.

    PubMed

    Powell, Mark D; Burke, Melissa S; Dahle, Dalia

    2011-03-01

    Anaemia is a common pathology associated with many infectious and non-infectious diseases. The effects of haemolytic anaemia induced by i.p. injection of phenylhydrazine (PHZ) were studied in Atlantic cod. Phenylhydrazine injection (0.3 mg kg(-1)) in a DMSO and saline vehicle induced a reproducible and stable anaemia reducing haematocrit, (Hct) by 62% over 3 weeks. Controls consisted of fish injected with saline and DMSO/saline vehicle with minimal effects on Hct or whole blood haemoglobin (Hb). Although anaemia resulted in reduced blood lactate and glucose in PHZ injected fish, there were no effects of anaemia on blood, sodium, chloride or potassium. Similarly, there were no changes in the relative proportions of leucocytes in the blood although an increase in the number of immature erythrocytes was observed in the anaemic fish. Anaemic fish showed a 29 and 22% increase in cardiac somatic index (CSI) relative to saline and vehicle controls, respectively, although there were no significant differences in the linear dimensions of the ventricle. Changes in cardiac somatic and ventricular somatic index correlated positively and significantly with Hct but not with whole blood Hb concentration. Anaemic fish had significantly reduced resting routine oxygen consumption compared with vehicle controls but were not able to increase oxygen consumption following a bout of exhaustive exercise. Plasma lactate concentrations increased significantly after exercise to a greater extent in anaemic fish compared with vehicle control fish. Phenylhydrazine is a useful model for studying haemolytic anaemia in Atlantic cod with minimal effects on blood biochemistry and haematology and clearly reduces the aerobic capacity in Atlantic cod. PMID:20585853

  6. Modeling Oxygen Transport in the Human Placenta

    NASA Astrophysics Data System (ADS)

    Serov, Alexander; Filoche, Marcel; Salafia, Carolyn; Grebenkov, Denis

    Efficient functioning of the human placenta is crucial for the favorable pregnancy outcome. We construct a 3D model of oxygen transport in the placenta based on its histological cross-sections. The model accounts for both diffusion and convention of oxygen in the intervillous space and allows one to estimate oxygen uptake of a placentone. We demonstrate the existence of an optimal villi density maximizing the uptake and explain it as a trade-off between the incoming oxygen flow and the absorbing villous surface. Calculations performed for arbitrary shapes of fetal villi show that only two geometrical characteristics - villi density and the effective villi radius - are required to predict fetal oxygen uptake. Two combinations of physiological parameters that determine oxygen uptake are also identified: maximal oxygen inflow of a placentone and the Damköhler number. An automatic image analysis method is developed and applied to 22 healthy placental cross-sections demonstrating that villi density of a healthy human placenta lies within 10% of the optimal value, while overall geometry efficiency is rather low (around 30-40%). In a perspective, the model can constitute the base of a reliable tool of post partum oxygen exchange efficiency assessment in the human placenta. Also affiliated with Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, USA.

  7. Safety Standard for Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA's standard for oxygen system design, materials selection, operation, and transportation is presented. Minimum guidelines applicable to NASA Headquarters and all NASA Field Installations are contained.

  8. Case-Based Learning of Blood Oxygen Transport

    ERIC Educational Resources Information Center

    Cliff, William H.

    2006-01-01

    A case study about carbon monoxide poisoning was used help students gain a greater understanding of the physiology of oxygen transport by the blood. A review of student answers to the case questions showed that students can use the oxygen-hemoglobin dissociation curve to make meaningful determinations of oxygen uptake and delivery. However, the…

  9. Radionuclides in haematology

    SciTech Connect

    Lewis, S.M.; Bayly, R.J.

    1986-01-01

    This book contains the following chapters: Some prerequisites to the use of radionuclides in haematology; Instrumentation and counting techniques; In vitro techniques; Cell labelling; Protein labelling; Autoradiography; Imaging and quantitative scanning; Whole body counting; Absorption and excretion studies; Blood volume studies; Plasma clearance studies; and Radionuclide blood cell survival studies.

  10. Mathematical Model of Oxygen Transport in Tuberculosis Granulomas

    PubMed Central

    Datta, Meenal; Via, Laura E.; Chen, Wei; Baish, James W.; Xu, Lei; Barry, Clifton E.; Jain, Rakesh K.

    2016-01-01

    Pulmonary granulomas—the hallmark of Mycobacterium tuberculosis (MTB) infection—are dense cellular lesions that often feature regions of hypoxia and necrosis, partially due to limited transport of oxygen. Low oxygen in granulomas can impair the host immune response, while MTB are able to adapt and persist in hypoxic environments. Here, we used a physiologically based mathematical model of oxygen diffusion and consumption to calculate oxygen profiles within the granuloma, assuming Michaelis–Menten kinetics. An approximate analytical solution—using a priori and newly estimated parameters from experimental data in a rabbit model of tuberculosis—was able to predict the size of hypoxic and necrotic regions in agreement with experimental results from the animal model. Such quantitative understanding of transport limitations can inform future tuberculosis therapeutic strategies that may include adjunct host-directed therapies that facilitate oxygen and drug delivery for more effective treatment. PMID:26253038

  11. Mathematical Model of Oxygen Transport in Tuberculosis Granulomas.

    PubMed

    Datta, Meenal; Via, Laura E; Chen, Wei; Baish, James W; Xu, Lei; Barry, Clifton E; Jain, Rakesh K

    2016-04-01

    Pulmonary granulomas-the hallmark of Mycobacterium tuberculosis (MTB) infection-are dense cellular lesions that often feature regions of hypoxia and necrosis, partially due to limited transport of oxygen. Low oxygen in granulomas can impair the host immune response, while MTB are able to adapt and persist in hypoxic environments. Here, we used a physiologically based mathematical model of oxygen diffusion and consumption to calculate oxygen profiles within the granuloma, assuming Michaelis-Menten kinetics. An approximate analytical solution-using a priori and newly estimated parameters from experimental data in a rabbit model of tuberculosis-was able to predict the size of hypoxic and necrotic regions in agreement with experimental results from the animal model. Such quantitative understanding of transport limitations can inform future tuberculosis therapeutic strategies that may include adjunct host-directed therapies that facilitate oxygen and drug delivery for more effective treatment. PMID:26253038

  12. Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes

    SciTech Connect

    Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L.; Kleefisch, M.S.; Udovich, C.A.

    1996-05-01

    Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

  13. Intramyocardial oxygen transport by quantitative diffuse reflectance spectroscopy in calves

    NASA Astrophysics Data System (ADS)

    Lindbergh, Tobias; Larsson, Marcus; Szabó, Zoltán; Casimir-Ahn, Henrik; Strömberg, Tomas

    2010-03-01

    Intramyocardial oxygen transport was assessed during open-chest surgery in calves by diffuse reflectance spectroscopy using a small intramuscular fiber-optic probe. The sum of hemo- and myoglobin tissue fraction and oxygen saturation, the tissue fraction and oxidation of cytochrome aa3, and the tissue fraction of methemoglobin were estimated using a calibrated empirical light transport model. Increasing the oxygen content in the inhaled gas, 21%-50%-100%, in five calves (group A) gave an increasing oxygen saturation of 19+/-4%, 24+/-5%, and 28+/-8% (p<0.001, ANOVA repeated measures design) and mean tissue fractions of 1.6% (cytochrome aa3) and 1.1% (hemo- and myoglobin). Cardiac arrest in two calves gave an oxygen saturation lower than 5%. In two calves (group B), a left ventricular assistive device (LVAD pump) was implanted. Oxygen saturation in group B animals increased with LVAD pump speed (p<0.001, ANOVA) and with oxygen content in inhaled gas (p<0.001, ANOVA). The cytochrome aa3 oxidation level was above 96% in both group A and group B calves, including the two cases involving cardiac arrest. In conclusion, the estimated tissue fractions and oxygenation/oxidation levels of the myocardial chromophores during respiratory and hemodynamic provocations were in agreement with previously presented results, demonstrating the potential of the method.

  14. Oxygen Transport in Melts Based on V2O5

    NASA Astrophysics Data System (ADS)

    Klimashin, Anton; Belousov, Valery

    2016-02-01

    An oxygen ion transport model was developed for oxide melts based on V2O5. Within the framework of this model, the values of the parabolic rate constant of catastrophic oxidation of V2O5-deposited copper and the oxygen flux through the slags based on molten V2O5 were calculated and compared with experimental data. The calculated and experimental values are of the same order of magnitude which shows an adequacy of the model.

  15. Oxygen radicals diminish dopamine transporter function in rat striatum.

    PubMed

    Fleckenstein, A E; Metzger, R R; Beyeler, M L; Gibb, J W; Hanson, G R

    1997-09-01

    Incubation of striatal synaptosomes with the oxygen radical generating enzyme, xanthine oxidase, decreased [3H]dopamine uptake: an effect attributable to a decreased Vmax. Concurrent incubation with the superoxide radical scavenger, superoxide dismutase, abolished the xanthine oxidase-induced decrease. These results indicate that, like methamphetamine administration in vivo, reactive oxygen species diminish dopamine transporter function in vitro. The significance of these findings to mechanisms responsible for effects of methamphetamine is discussed. PMID:9346337

  16. Method measuring oxygen tension and transport within subcutaneous devices

    PubMed Central

    Weidling, John; Sameni, Sara; Lakey, Jonathan R. T.; Botvinick, Elliot

    2014-01-01

    Abstract. Cellular therapies hold promise to replace the implantation of whole organs in the treatment of disease. For most cell types, in vivo viability depends on oxygen delivery to avoid the toxic effects of hypoxia. A promising approach is the in situ vascularization of implantable devices which can mediate hypoxia and improve both the lifetime and utility of implanted cells and tissues. Although mathematical models and bulk measurements of oxygenation in surrounding tissue have been used to estimate oxygenation within devices, such estimates are insufficient in determining if supplied oxygen is sufficient for the entire thickness of the implanted cells and tissues. We have developed a technique in which oxygen-sensitive microparticles (OSMs) are incorporated into the volume of subcutaneously implantable devices. Oxygen partial pressure within these devices can be measured directly in vivo by an optical probe placed on the skin surface. As validation, OSMs have been incorporated into alginate beads, commonly used as immunoisolation devices to encapsulate pancreatic islet cells. Alginate beads were implanted into the subcutaneous space of Sprague–Dawley rats. Oxygen transport through beads was characterized from dynamic OSM signals in response to changes in inhaled oxygen. Changes in oxygen dynamics over days demonstrate the utility of our technology. PMID:25162910

  17. Oxygen transport as a structure probe for amorphous polymeric systems

    NASA Astrophysics Data System (ADS)

    Liu, Richard Yufeng

    Although permeability of small molecules is often measured as an important performance property, deeper analysis of the transport characteristics provides insight into polymer structure, especially if used in combination with other characterization techniques. Transport of small gas molecules "senses" the permeable amorphous structure and probes the nature of free volume. This work focuses on oxygen transport, supplemented with other methods of physical analysis, as a probe for: (1) the nature of free volume in the oriented glassy state, (2) the role of amorphous phase orientation and strain-induced crystallization on oxygen barrier properties of polyester blends, and (3) the nature of interphase between immiscible amorphous polymers in forced-assemblies. In the first part, the mechanism of oxygen transport in oriented glassy polyesters is examined. PET, PETBB55, and PEN were oriented by cold-drawing. Densification of the glassy state correlates with conformational transformation of glycol linkages from gauche to trans. Orientation is seen as a process of decreasing the amount of excess-hole free volume and bringing the nonequilibrium polymer glass closer to the equilibrium condition. Further insights into the free volume structure are obtained by exploring the relationships between free volume structure and oxygen transport property using a simple lattice-hole model. In the second part, oxygen transport through polyester blends is investigated. It is found that cold-drawing the blocky PET/PETBB55 produces highly oriented PETBB55 frustrated LCP microfibrils, which prevent relaxation of the continuous PET phase. On the other hand, careful examination of oxygen barrier for the PET/PEI blends leads to a two-phase model from which the amount of crystallinity and the amorphous phase density are determined. In the third part, oxygen permeability is utilized as a powerful probe for interphase thickness between immiscible polymers, which is as thin as a few nanometers. We

  18. Transportation of Critically Ill Patients on Extracorporeal Membrane Oxygenation

    PubMed Central

    Broman, L. Mikael; Frenckner, Björn

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) may be a life-saving procedure for patients with severe reversible pulmonary or cardiac failure or for patients in need for a bridge to transplantation. ECMO is provided by specialized centers, but patients in need of ECMO are frequently taken care of at other centers. Conventional transports to an ECMO center can be hazardous and deaths have been described. For this reason, many ECMO centers have developed transport programs with mobile ECMO. After request, the mobile team including all necessary equipment to initiate ECMO is sent to the referring hospital, where the patient is cannulated and ECMO commenced. The patient is then transported on ECMO to the ECMO facility by road, helicopter, or fixed-wing aircraft depending on distance, weather conditions, etc. Eight publications have reported series of more than 50 transports on ECMO of which the largest included over 700. Together, these papers report on more than 1400 patient transports on ECMO. Two deaths during transport have occurred. A number of other adverse events are described, but without effect on patient outcome. Survival of patients transported on ECMO is equivalent to that of non-transported ECMO patients. It is concluded that long-, short-distance interhospital transports on ECMO can be performed safely. The staff should be experienced and highly competent in intensive care, ECMO cannulation, ECMO treatment, intensive care transport, and air transport medicine. PMID:27379221

  19. Transportation of Critically Ill Patients on Extracorporeal Membrane Oxygenation.

    PubMed

    Broman, L Mikael; Frenckner, Björn

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) may be a life-saving procedure for patients with severe reversible pulmonary or cardiac failure or for patients in need for a bridge to transplantation. ECMO is provided by specialized centers, but patients in need of ECMO are frequently taken care of at other centers. Conventional transports to an ECMO center can be hazardous and deaths have been described. For this reason, many ECMO centers have developed transport programs with mobile ECMO. After request, the mobile team including all necessary equipment to initiate ECMO is sent to the referring hospital, where the patient is cannulated and ECMO commenced. The patient is then transported on ECMO to the ECMO facility by road, helicopter, or fixed-wing aircraft depending on distance, weather conditions, etc. Eight publications have reported series of more than 50 transports on ECMO of which the largest included over 700. Together, these papers report on more than 1400 patient transports on ECMO. Two deaths during transport have occurred. A number of other adverse events are described, but without effect on patient outcome. Survival of patients transported on ECMO is equivalent to that of non-transported ECMO patients. It is concluded that long-, short-distance interhospital transports on ECMO can be performed safely. The staff should be experienced and highly competent in intensive care, ECMO cannulation, ECMO treatment, intensive care transport, and air transport medicine. PMID:27379221

  20. Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba.

    PubMed

    Hoffmann, Friederike; Røy, Hans; Bayer, Kristina; Hentschel, Ute; Pfannkuchen, Martin; Brümmer, Franz; de Beer, Dirk

    2008-01-01

    The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba specimens with Clark-type oxygen microelectrodes (tip diameters 18-30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges, which allows total oxygen consumption rates of 6-12 μmol cm(-3) sponge day(-1). Sponges of different sizes had similar diffusional uptake rates, which is explained by their similar surface/volume ratios. In pumping sponges, oxygen consumption rates were between 22 and 37 μmol cm(-3) sponge day(-1), and the entire tissue was oxygenated. Combining different approaches of direct oxygen measurement in living sponges with a dynamic model, we can show that tissue anoxia is a direct function of the pumping behavior. The sponge-microbe system of A. aerophoba thus has the possibility to switch actively between aerobic and anaerobic metabolism by stopping the water flow for more than 15 min. These periods of anoxia will greatly influence physiological variety and activity of the sponge microbes. Detailed knowledge about the varying chemical microenvironments in sponges will help to develop protocols to cultivate sponge-associated microbial lineages and improve our understanding of the sponge-microbe-system. PMID:24391232

  1. Computation of the unsteady facilitated transport of oxygen in hemoglobin

    NASA Technical Reports Server (NTRS)

    Davis, Sanford

    1990-01-01

    The transport of a reacting permeant diffusing through a thin membrane is extended to more realistic dissociation models. A new nonlinear analysis of the reaction-diffusion equations, using implicit finite-difference methods and direct block solvers, is used to study the limits of linearized and equilibrium theories. Computed curves of molecular oxygen permeating through hemoglobin solution are used to illustrate higher-order reaction models, the effect of concentration boundary layers at the membrane interfaces, and the transient buildup of oxygen flux.

  2. Haematological abnormalities in mitochondrial disorders

    PubMed Central

    Finsterer, Josef; Frank, Marlies

    2015-01-01

    INTRODUCTION This study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence. METHODS The blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as ‘definite’, ‘probable’ or ‘possible’ according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded. RESULTS A total of 46 patients (‘definite’ = 5; ‘probable’ = 9; ‘possible’ = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities. CONCLUSION MID should be considered if a patient’s abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem. PMID:26243978

  3. Oxygen transport as a structure probe for heterogeneous polymeric systems

    NASA Astrophysics Data System (ADS)

    Hu, Yushan

    Although permeability of small molecules is often measured as an important performance property, deeper analysis of the transport characteristics provides insight into polymer structure, especially if used in combination with other characterization techniques. Transport of small gas molecules senses the permeable amorphous structure and probes the nature of free volume. This work focuses on oxygen transport, supplemented with other methods of physical analysis, as a probe for: (1) the nature of free volume and crystalline morphology in the crystallized glassy state, (2) the nature of free volume and hierarchical structure in liquid crystalline polymers, and (3) the role of dispersed polyamide phase geometry on oxygen barrier properties of poly(ethylene terephthalate) (PET)/polyamide blends. In the first part, the improvement in oxygen-barrier properties of glassy polyesters by crystallization was examined. Examples included poly(ethylene naphthalate) (PEN), and a copolymer based on PET in which 55 mol% terephthalate was replaced with 4,4'-bibenzoate. Explanation of the unexpectedly high solubility of crystallized PEN required a two-phase transport model consisting of an impermeable crystalline phase of constant density and a permeable amorphous phase of variable density. The resulting relationship between oxygen solubility and amorphous phase density was consistent with free volume concepts of gas sorption. In the second part, oxygen barrier properties of liquid crystalline (LC) polyesters based on poly(diethylene glycol 4,4'-bibenzoate) (PDEGBB) were studied. This study extended the 2-phase transport model for oxygen transport of non-LC crystalline polymers to a smectic LCP. It was possible to systematically vary the solid state structure of (PDEGBB) from LC glass to crystallized LC glass. The results were consistent with a liquid crystalline state intermediate between the permeable amorphous glass and the impermeable 3-dimensional crystal. In this interpretation

  4. Limits for oxygen and substrate transport in mammals.

    PubMed

    Hoppeler, H; Weibel, E R

    1998-04-01

    Environmental oxygen is transported by the respiratory cascade to the site of oxidation in active tissues. Under conditions of heavy exercise, it is ultimately the working skeletal muscle cells that set the aerobic demand because over 90 % of energy is spent in muscle cells. The pathways for oxygen and substrates converge in muscle mitochondria. In mammals, a structural limitation of carbohydrate and lipid transfer from the microvascular system to the muscle cells is reached at a moderate work intensity (i.e. at 40-50 % of VO2max). At higher work rates, intracellular substrate stores must be used for oxidation. Because of the importance of these intracellular stores for aerobic work, we find larger intramyocellular substrate stores in 'athletic' species as well as in endurance-trained human athletes. The transfer limitations for carbohydrates and lipids at the level of the sarcolemma imply that the design of the respiratory cascade from lungs to muscle mitochondria reflects primarily oxygen demand. Comparative studies indicate that the oxidative capacity of skeletal muscle tissue, and hence maximal oxygen demand, is adjusted by varying mitochondrial content. At the level of microcirculatory oxygen supply, it is found that muscle tissue capillarity is adjusted to muscle oxygen demand but that the capillary erythrocyte volume also plays a role. Oxygen delivery by the heart has long been recognized to be a key link in the oxygen transport chain. In allometric variation it is heart rate and in adaptive variation it is essentially stroke volume, and hence heart size, that determines maximal cardiac output. Again, haematocrit is an important variable that allows the heart of athletic species to generate higher flux rates for oxygen. The pulmonary gas exchanger offers only a negligible resistance to oxygen flux to the periphery. However, in contrast to all other steps in the respiratory cascade, the lungs have only a minimal phenotypical plasticity and appear, therefore

  5. Haematological manifestations of lupus

    PubMed Central

    Fayyaz, Anum; Igoe, Ann; Kurien, Biji T; Danda, Debashish; James, Judith A; Stafford, Haraldine A; Scofield, R Hal

    2015-01-01

    Our purpose was to compile information on the haematological manifestations of systemic lupus erythematosus (SLE), namely leucopenia, lymphopenia, thrombocytopenia, autoimmune haemolytic anaemia (AIHA), thrombotic thrombocytopenic purpura (TTP) and myelofibrosis. During our search of the English-language MEDLINE sources, we did not place a date-of-publication constraint. Hence, we have reviewed previous as well as most recent studies with the subject heading SLE in combination with each manifestation. Neutropenia can lead to morbidity and mortality from increased susceptibility to infection. Severe neutropenia can be successfully treated with granulocyte colony-stimulating factor. While related to disease activity, there is no specific therapy for lymphopenia. Severe lymphopenia may require the use of prophylactic therapy to prevent select opportunistic infections. Isolated idiopathic thrombocytopenic purpura maybe the first manifestation of SLE by months or even years. Some manifestations of lupus occur more frequently in association with low platelet count in these patients, for example, neuropsychiatric manifestation, haemolytic anaemia, the antiphospholipid syndrome and renal disease. Thrombocytopenia can be regarded as an important prognostic indicator of survival in patients with SLE. Medical, surgical and biological treatment modalities are reviewed for this manifestation. First-line therapy remains glucocorticoids. Through our review, we conclude glucocorticoids do produce a response in majority of patients initially, but sustained response to therapy is unlikely. Glucocorticoids are used as first-line therapy in patients with SLE with AIHA, but there is no conclusive evidence to guide second-line therapy. Rituximab is promising in refractory and non-responding AIHA. TTP is not recognised as a criteria for classification of SLE, but there is a considerable overlap between the presenting features of TTP and SLE, and a few patients with SLE have concurrent

  6. [Current views on oxygen transport from blood to tissues].

    PubMed

    Ivanov, K P

    2001-01-01

    During the recent 25-30 years, sophisticated experiments and mathematical simulation significantly changed the generally accepted theory of oxygen transport in tissue, which was based on two major postulates, namely: 1) Blood flows in capillaries continuously at uniform velocity, 2) Gas circulation between blood and tissue takes place exclusively in capillaries. As was shown by modern research techniques, blood flow in microvessels has irregular sharp velocity fluctuations in very short time intervals (seconds). In addition, mean velocity of blood flow in microvessels of the same caliber and the same micro-region of tissue may differ several times. Therefore, efficiency of microcirculation reactions may be assessed exclusively witH mean blood velocity in capillaries of the whole micro-region, and with complicated changes of the histogram of mean velocity distribution in capillaries. It was shown that arteriolas and venulas of inactive muscles and brain account for 30 to 50% of gas circulation between blood and tissue. This resulted in fundamental change of the previous postulates in the area of tissue gas circulation physiology, and, in effect, in replacement of oxygen transport paradigm created by A. Krog. This study is an attempt to present a new modern concept of oxygen transport in tissue, to show its research significance, and possible applications. PMID:11764645

  7. Oxygen nonstoichiometry and transport properties of strontium substituted lanthanum ferrite

    SciTech Connect

    Sogaard, Martin Vang Hendriksen, Peter; Mogensen, Mogens

    2007-04-15

    This study presents an investigation of the properties of (La{sub 0.6}Sr{sub 0.4}){sub 0.99}FeO{sub 3-{delta}} (LSF40) covering thermomechanical properties, oxygen nonstoichiometry and electronic and ionic conductivity. Finally, oxygen permeation experiments have been carried out and the oxygen flux has been determined as a function of temperature and driving force. The electrical conductivity was measured using a 4 probe method. It is shown that the electrical conductivity is a function of the charge carrier concentration only. The electron hole mobility is found to decrease with increasing charge carrier concentration in agreement with recent literature. Values of the chemical diffusion coefficient, D{sub Chem}, and the surface exchange coefficient, k{sub Ex}, have been determined using electrical conductivity relaxation. At 800 deg. CD{sub Chem} is determined to be 6.2x10{sup -6}cm{sup 2}s{sup -1} with an activation energy of 137kJmol{sup -1}. The surface exchange coefficient is found to decrease with decreasing oxygen partial pressure. Oxygen permeation experiments were carried out. The flux through a membrane placed between air and wet hydrogen/nitrogen was J{sub O{sub 2}}{approx}1.8x10{sup -6}molcm{sup -2}s{sup -1} (corresponding to an equivalent electrical current density of 670mAcm{sup -2}). The oxygen permeation measurements are successfully interpreted based on the oxygen nonstoichiometry data and the determined transport parameters.

  8. Oxygen transport properties estimation by DSMC-CT simulations

    SciTech Connect

    Bruno, Domenico; Frezzotti, Aldo; Ghiroldi, Gian Pietro

    2014-12-09

    Coupling DSMC simulations with classical trajectories calculations is emerging as a powerful tool to improve predictive capabilities of computational rarefied gas dynamics. The considerable increase of computational effort outlined in the early application of the method (Koura,1997) can be compensated by running simulations on massively parallel computers. In particular, GPU acceleration has been found quite effective in reducing computing time (Ferrigni,2012; Norman et al.,2013) of DSMC-CT simulations. The aim of the present work is to study rarefied Oxygen flows by modeling binary collisions through an accurate potential energy surface, obtained by molecular beams scattering (Aquilanti, et al.,1999). The accuracy of the method is assessed by calculating molecular Oxygen shear viscosity and heat conductivity following three different DSMC-CT simulation methods. In the first one, transport properties are obtained from DSMC-CT simulations of spontaneous fluctuation of an equilibrium state (Bruno et al, Phys. Fluids, 23, 093104, 2011). In the second method, the collision trajectory calculation is incorporated in a Monte Carlo integration procedure to evaluate the Taxman’s expressions for the transport properties of polyatomic gases (Taxman,1959). In the third, non-equilibrium zero and one-dimensional rarefied gas dynamic simulations are adopted and the transport properties are computed from the non-equilibrium fluxes of momentum and energy. The three methods provide close values of the transport properties, their estimated statistical error not exceeding 3%. The experimental values are slightly underestimated, the percentage deviation being, again, few percent.

  9. Oxygen transport in ceria: a first-principles study

    NASA Astrophysics Data System (ADS)

    Sergei, Simak

    2012-02-01

    Ceria (CeO2) is an important material for environmentally benign applications, ranging from solid-oxide fuel cells (SOFC) to oxygen storage [1-2]. The key characteristic needed to be improved is the mobility of oxygen ions. Optimization of ionic transport in ceria has been the topic of many studies. In particular, it has been discovered how the ionic conductivity in ceria might be improved by choosing the proper kind and concentration of dopants [3]. In this presentation we will approach the problem from a different direction by adjusting structural parameters of ceria via the change of external conditions. A systematic first-principles study of the energy landscape and kinetics of reduced ceria as a function of external parameters reveals a physically transparent way to improve oxygen transport in ceria. [4pt] [1] N. Skorodumova, S. Simak, B. Lundqvist, I. Abrikosov, and B. Johansson, Physical Review Letters 89, 14 (2002). [0pt] [2] A. Trovarelli, in Catalysis by Ceria and related materials (Imperial College Press, London, 2002). [0pt] [3] D. A. Andersson, S. I. Simak, N. V. Skorodumova, I. A.Abrikosov, and B. Johansson, Proceedings of the National Academy of Sciences of the United States of America 103, 3518 (2006).

  10. A model for oxygen transport and consumption in the unsaturated zone

    NASA Astrophysics Data System (ADS)

    Refsgaard, J. C.; Christensen, T. H.; Ammentorp, H. C.

    1991-12-01

    An oxygen transport and consumption model has been developed as a submodel to a general numerical model for solute transport in the unsaturated zone. The model comprises diffusive and convective transport of oxygen in soil air, convective transport and oxygen consumption in free water, and diffusive transport and a constant-rate oxygen consumption in the water-saturated soil crumbs. The model also estimates the anaerobic fraction of the water-saturated crumbs where no oxygen consumption takes place. The model dynamics and applicability are illustrated using the examples of the operation of a waste water infiltration plant and of anaerobic zones in the soil of importance for modelling denitrification.

  11. Oxygen transport is not compromised at high temperature in pythons.

    PubMed

    Fobian, Dannie; Overgaard, Johannes; Wang, Tobias

    2014-11-15

    To evaluate whether the 'oxygen and capacity limited thermal tolerance' model (OCLTT) applies to an air-breathing ectothermic vertebrate, we measured oxygen uptake (V̇(O₂)), cardiac performance and arterial blood gases during a progressive rise of temperature from 30 to 40°C in the snake Python regius. V̇(O₂) of fasting snakes increased exponentially with temperature whereas V̇(O₂) of digesting snakes at high temperatures plateaued at a level 3- to 4-fold above fasting. The high and sustained aerobic metabolism over the entire temperature range was supported by pronounced tachycardia at all temperatures, and both fasting and digesting snakes maintained a normal acid-base balance without any indication of anaerobic metabolism. All snakes also maintained high arterial PO2, even at temperatures close to the upper lethal temperature. Thus, there is no evidence of a reduced capacity for oxygen transport at high temperatures in either fasting or digesting snakes, suggesting that the upper thermal tolerance of this species is limited by other factors. PMID:25267848

  12. Improving haematology care in Wales.

    PubMed

    Perett, Shelagh

    2002-04-17

    Care for patients with a malignant haematological disorder in Wales has been revised significantly since the mid-1990s. Recommendations from expert groups stated that a uniformly high standard of care should be provided as close to the patient's home as possible and variations in practice that had been causing concern and distress to patients and their families be reduced. The All Wales Haematology Nurses Group was established to promote and disseminate standards and guidelines that would contribute to achieving these aims. The basis for the group's work was transformational leadership and collaborative practice. Work is ongoing and the group is planning to consolidate achievements to date through country-wide audit and professional education. PMID:11998241

  13. Bone biopsy in haematological disorders.

    PubMed Central

    Burkhardt, R; Frisch, B; Bartl, R

    1982-01-01

    Bone marrow biopsies are now widely used in the investigation and follow-up of many diseases. Semi-thin sections of 8216 undecalcified biopsies of patients with haematological disorders were studied. Observations were made on the cytopenias and the myelodysplastic syndromes, the acute leukaemias the myeloproliferative disorders, Hodgkin's disease and the malignant lymphomas including multiple myeloma, hairy cell leukaemia and angioimmunoblastic lymphadenopathy. Bone marrow biopsies are essential for the differential diagnosis of most cytopenias and for the early recognition of fibrosis which most frequently occurred as a consequence of megakaryocytic proliferation in the myeloproliferative disorders. Different patterns of bone marrow involvement were found in the lymphoproliferative disorders and both their type and extent constituted factors of prognostic significance. A survey of the literature is given and the conclusion is drawn that bone marrow biopsies provide indispensible information for the diagnostic evaluation and the follow-up of patients with haematological disorders. Images PMID:7040489

  14. Managing haematological disorders during pregnancy.

    PubMed

    Koh, Mickey B C; Lao, Zhen Tang; Rhodes, Elizabeth

    2013-12-01

    The management of patients with pre-existing haematological diseases during pregnancy can be particularly challenging. The potential maternal and foetal toxicities from treatment regimens including chemotherapy for malignant haematological disorders mean that joint management between obstetricians and haematologists is essential for achieving good outcomes for both mother and baby. Patients with inherited or acquired disorders of haemostasis including platelets (essential thrombocythaemia) and coagulation (antiphospholipid syndrome) resulting in a pro-thrombotic state also require special consideration as pregnancy is generally considered to be a pro-thrombotic condition which could exacerbate the pre-existing disorder. The choice, timing and duration of anticoagulation or anti-platelet therapy require careful coordination during the antenatal, perinatal as well as postnatal periods to ensure that both maternal and foetal risks are taken into consideration. Pregnancy in women with sickle cell disease has long been identified as high risk with medical and pregnancy related risks being more common compared to women without it. A range of foetal risks have also been reported but improvement in outcomes has been seen with better obstetric and haematological care and the emphasis on multidisciplinary teamwork. The meticulous management of iron overload and risks associated with repeated blood transfusions extends into the care of pregnant women with other haemoglobinopathies like thalassemias. PMID:24060203

  15. Global simulation of coupled carbon and oxygen transport in a Czochralski furnace for silicon crystal growth

    NASA Astrophysics Data System (ADS)

    Gao, B.; Kakimoto, K.

    2010-10-01

    For accurate prediction of carbon and oxygen impurities in a single crystal produced by the Czochralski method, global simulation of coupled oxygen and carbon transport in the whole furnace was implemented. Both gas-phase transportation and liquid-phase transportation of oxygen and carbon were considered. With five chemical reactions considered, SiO and CO concentrations in gas and C and O atom concentrations in silicon melt were solved simultaneously. The simulation results show good agreement with experimental data.

  16. The Pathway for Oxygen: Tutorial Modelling on Oxygen Transport from Air to Mitochondrion: The Pathway for Oxygen.

    PubMed

    Bassingthwaighte, James B; Raymond, Gary M; Dash, Ranjan K; Beard, Daniel A; Nolan, Margaret

    2016-01-01

    The 'Pathway for Oxygen' is captured in a set of models describing quantitative relationships between fluxes and driving forces for the flux of oxygen from the external air source to the mitochondrial sink at cytochrome oxidase. The intervening processes involve convection, membrane permeation, diffusion of free and heme-bound O2 and enzymatic reactions. While this system's basic elements are simple: ventilation, alveolar gas exchange with blood, circulation of the blood, perfusion of an organ, uptake by tissue, and consumption by chemical reaction, integration of these pieces quickly becomes complex. This complexity led us to construct a tutorial on the ideas and principles; these first PathwayO2 models are simple but quantitative and cover: (1) a 'one-alveolus lung' with airway resistance, lung volume compliance, (2) bidirectional transport of solute gasses like O2 and CO2, (3) gas exchange between alveolar air and lung capillary blood, (4) gas solubility in blood, and circulation of blood through the capillary syncytium and back to the lung, and (5) blood-tissue gas exchange in capillaries. These open-source models are at Physiome.org and provide background for the many respiratory models there. PMID:26782201

  17. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    DOEpatents

    Kelly, Sean M; Kromer, Brian R; Litwin, Michael M; Rosen, Lee J; Christie, Gervase Maxwell; Wilson, Jamie R; Kosowski, Lawrence W; Robinson, Charles

    2014-01-07

    A method and apparatus for producing heat used in a synthesis gas production is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the stream reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5.

  18. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    DOEpatents

    Kelly, Sean M.; Kromer, Brian R.; Litwin, Michael M.; Rosen, Lee J.; Christie, Gervase Maxwell; Wilson, Jamie R.; Kosowski, Lawrence W.; Robinson, Charles

    2016-01-19

    A method and apparatus for producing heat used in a synthesis gas production process is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the steam reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5

  19. Contributions of advective and diffusive oxygen transport through multilayer composite caps over mine waste.

    PubMed

    Kim, Hong; Benson, Craig H

    2004-07-01

    The relative contributions of four mechanisms of oxygen transport in multilayer composite (MLC) caps placed over oxygen-consuming mine waste were evaluated using numerical and analytical methods. MLC caps are defined here as caps consisting of earthen and geosynthetic (polymeric) components where a composite barrier layer consisting of a geomembrane (1-2 mm thick polymeric sheet) overlying a clay layer is the primary barrier to transport. The transport mechanisms that were considered are gas-phase advective transport, gas-phase diffusive transport, liquid-phase advective transport via infiltrating precipitation and liquid-phase diffusive transport. A numerical model was developed to simulate gas-phase advective-diffusive transport of oxygen through a multilayer cap containing seven layers. This model was also used to simulate oxygen diffusion in the liquid phase. An approximate analytical method was used to compute the advective flux of oxygen in the liquid phase. The numerical model was verified for limiting cases using an analytical solution. Comparisons were also made between model predictions and field data for earthen caps reported by others. Results of the analysis show that the dominant mechanism for oxygen transport through MLC caps is gas-phase diffusion. For the cases that were considered, the gas-phase diffusive flux typically comprises at least 99% of the total oxygen flux. Thus, designers of MLC caps should focus on design elements and features that will limit diffusion of gas-phase oxygen. PMID:15145567

  20. Oxygen transport in off-stoichiometric uranium dioxide mediated by defect clustering dynamics

    SciTech Connect

    Yu, Jianguo Bai, Xian-Ming; El-Azab, Anter; Allen, Todd R.

    2015-03-07

    Oxygen transport is central to many properties of oxides such as stoichiometric changes, phase transformation, and ionic conductivity. In this paper, we report a mechanism for oxygen transport in uranium dioxide (UO{sub 2}) in which the kinetics is mediated by defect clustering dynamics. In particular, the kinetic Monte Carlo method has been used to investigate the kinetics of oxygen transport in UO{sub 2} under the condition of creation and annihilation of oxygen vacancies and interstitials as well as oxygen interstitial clustering, with variable off-stoichiometry and temperature conditions. It is found that in hypo-stoichiometric UO{sub 2−x}, oxygen transport is well described by the vacancy diffusion mechanism while in hyper-stoichiometric UO{sub 2+x}, oxygen interstitial cluster diffusion contributes significantly to oxygen transport kinetics, particularly at high temperatures and high off-stoichiometry levels. It is also found that di-interstitial clusters and single interstitials play dominant roles in oxygen diffusion while other larger clusters have negligible contributions. However, the formation, coalescence, and dissociation of these larger clusters indirectly affects the overall oxygen diffusion due to their interactions with mono and di-interstitials, thus providing an explanation of the experimental observation of saturation or even drop of oxygen diffusivity at high off-stoichiometry.

  1. Oxygen transport in off-stoichiometric uranium dioxide mediated by defect clustering dynamics

    NASA Astrophysics Data System (ADS)

    Yu, Jianguo; Bai, Xian-Ming; El-Azab, Anter; Allen, Todd R.

    2015-03-01

    Oxygen transport is central to many properties of oxides such as stoichiometric changes, phase transformation, and ionic conductivity. In this paper, we report a mechanism for oxygen transport in uranium dioxide (UO2) in which the kinetics is mediated by defect clustering dynamics. In particular, the kinetic Monte Carlo method has been used to investigate the kinetics of oxygen transport in UO2 under the condition of creation and annihilation of oxygen vacancies and interstitials as well as oxygen interstitial clustering, with variable off-stoichiometry and temperature conditions. It is found that in hypo-stoichiometric UO2-x, oxygen transport is well described by the vacancy diffusion mechanism while in hyper-stoichiometric UO2+x, oxygen interstitial cluster diffusion contributes significantly to oxygen transport kinetics, particularly at high temperatures and high off-stoichiometry levels. It is also found that di-interstitial clusters and single interstitials play dominant roles in oxygen diffusion while other larger clusters have negligible contributions. However, the formation, coalescence, and dissociation of these larger clusters indirectly affects the overall oxygen diffusion due to their interactions with mono and di-interstitials, thus providing an explanation of the experimental observation of saturation or even drop of oxygen diffusivity at high off-stoichiometry.

  2. Oxygen transport in off-stoichiometric uranium dioxide mediated by defect clustering dynamics.

    PubMed

    Yu, Jianguo; Bai, Xian-Ming; El-Azab, Anter; Allen, Todd R

    2015-03-01

    Oxygen transport is central to many properties of oxides such as stoichiometric changes, phase transformation, and ionic conductivity. In this paper, we report a mechanism for oxygen transport in uranium dioxide (UO2) in which the kinetics is mediated by defect clustering dynamics. In particular, the kinetic Monte Carlo method has been used to investigate the kinetics of oxygen transport in UO2 under the condition of creation and annihilation of oxygen vacancies and interstitials as well as oxygen interstitial clustering, with variable off-stoichiometry and temperature conditions. It is found that in hypo-stoichiometric UO(2-x), oxygen transport is well described by the vacancy diffusion mechanism while in hyper-stoichiometric UO(2+x), oxygen interstitial cluster diffusion contributes significantly to oxygen transport kinetics, particularly at high temperatures and high off-stoichiometry levels. It is also found that di-interstitial clusters and single interstitials play dominant roles in oxygen diffusion while other larger clusters have negligible contributions. However, the formation, coalescence, and dissociation of these larger clusters indirectly affects the overall oxygen diffusion due to their interactions with mono and di-interstitials, thus providing an explanation of the experimental observation of saturation or even drop of oxygen diffusivity at high off-stoichiometry. PMID:25747097

  3. Oxygen transport in off-stoichiometric uranium dioxide mediated by defect clustering dynamics

    DOE PAGESBeta

    Yu, Jianguo; Bai, Xian -Ming; El-Azab, Anter; Allen, Todd R.

    2015-03-05

    In this study, oxygen transport is central to many properties of oxides such as stoichiometric changes, phase transformation and ionic conductivity. In this paper, we report a mechanism for oxygen transport in uranium dioxide (UO2) in which the kinetics is mediated by defect clustering dynamics. In particular, the kinetic Monte Carlo (KMC) method has been used to investigate the kinetics of oxygen transport in UO2 under the condition of creation and annihilation of oxygen vacancies and interstitials as well as oxygen interstitial clustering, with variable offstoichiometry and temperature conditions. It is found that in hypo-stoichiometric UO2-x, oxygen transport is wellmore » described by the vacancy diffusion mechanism while in hyper-stoichiometric UO2+x, oxygen interstitial cluster diffusion contributes significantly to oxygen transport kinetics, particularly at high temperatures and high off-stoichiometry levels. It is also found that diinterstitial clusters and single interstitials play dominant roles in oxygen diffusion while other larger clusters have negligible contributions. However, the formation, coalescence and dissociation of these larger clusters indirectly affects the overall oxygen diffusion due to their interactions with mono and di-interstitials, thus providing a explanation of the experimental observation of saturation or even drop of oxygen diffusivity at high off-stoichiometry.« less

  4. Oxygen transport in off-stoichiometric uranium dioxide mediated by defect clustering dynamics

    SciTech Connect

    Yu, Jianguo; Bai, Xian -Ming; El-Azab, Anter; Allen, Todd R.

    2015-03-05

    In this study, oxygen transport is central to many properties of oxides such as stoichiometric changes, phase transformation and ionic conductivity. In this paper, we report a mechanism for oxygen transport in uranium dioxide (UO2) in which the kinetics is mediated by defect clustering dynamics. In particular, the kinetic Monte Carlo (KMC) method has been used to investigate the kinetics of oxygen transport in UO2 under the condition of creation and annihilation of oxygen vacancies and interstitials as well as oxygen interstitial clustering, with variable offstoichiometry and temperature conditions. It is found that in hypo-stoichiometric UO2-x, oxygen transport is well described by the vacancy diffusion mechanism while in hyper-stoichiometric UO2+x, oxygen interstitial cluster diffusion contributes significantly to oxygen transport kinetics, particularly at high temperatures and high off-stoichiometry levels. It is also found that diinterstitial clusters and single interstitials play dominant roles in oxygen diffusion while other larger clusters have negligible contributions. However, the formation, coalescence and dissociation of these larger clusters indirectly affects the overall oxygen diffusion due to their interactions with mono and di-interstitials, thus providing a explanation of the experimental observation of saturation or even drop of oxygen diffusivity at high off-stoichiometry.

  5. Haemodynamic and oxygen transport response during exchange transfusion for severe falciparum malaria.

    PubMed

    Beards, S C; Joynt, G M; Lipman, J

    1994-11-01

    We describe the haemodynamic and oxygen transport response in a patient undergoing exchange transfusion for severe falciparum malaria. We found that exchange transfusion produced a significant increase in left ventricular stroke work index, systemic oxygen delivery and oxygen consumption. This potentially beneficial effect of exchange transfusion has not been reported previously. PMID:7824413

  6. Manipulating Cofactor Binding Thermodynamics in an Artificial Oxygen Transport Protein

    PubMed Central

    Zhang, Lei; Ross Anderson, J. L.; Ahmed, Ismail; Norman, Jessica A.; Negron, Christopher; Mutter, Andrew C.; Dutton, P. Leslie; Koder, Ronald L.

    2013-01-01

    We report the mutational analysis of an artificial oxygen transport protein, HP-7, which operates via a mechanism akin to human neuroglobin and cytoglobin. This protein destabilizes one of two heme-ligating histidine residues by coupling histidine side chain ligation with the burial of three charged glutamate residues on the same helix. Replacement of these glutamate residues with alanine, which is uncharged, increases the affinity of the distal histidine ligand by a factor of thirteen. Paradoxically, it also decreases heme binding affinity by a factor of five in the reduced state and sixty in the oxidized state. Application of a three-state binding model, in which an initial pentacoordinate binding event is followed by a protein conformational change to hexacoordinate, provides insight into the mechanism of this seemingly counterintuitive result: the initial pentacoordinate encounter complex is significantly destabilized by the loss of the glutamate side chains, and the increased affinity for the distal histidine only partially compensates. These results point to the importance of considering each oxidation and conformational state in the design of functional artificial proteins. PMID:22004125

  7. Oxygen Transport Across Space-Filling Biological Membranes

    NASA Astrophysics Data System (ADS)

    Hou, Chen

    2005-03-01

    Space-filling fractal surfaces play a fundamental role in how organisms function and in how structure determines function at various levels. In this project we developed an efficient and powerful algorithm, rope-walk algorithm, for solving diffusion equations of transport of species across the space-filling fractal surface. We performed analytic computations of the oxygen current across the alveolar membranes in the lung, as a function of diffusion coefficient and membrane permeability, using the rope-walk algorithm, without adjustable parameters. The analytic calculation identifies the four cases as sharply delineated screening regimes and finds that the lung operates in the partial-screening regime, close to the transition to no screening, and in the no-screening regime, for respiration at rest and in exercise respectively. The gas exchange satisfies six criteria of optimal design: maximum current; minimum waste of surface area; minimum permeability; maximum fault tolerance; minimum waiting time and maximum current increase when going from rest to exercise. This extraordinary, multiply optimized performance is a direct consequence of the space-filling membrane architecture.

  8. Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation

    PubMed Central

    Gagnon, Louis; Smith, Amy F.; Boas, David A.; Devor, Anna; Secomb, Timothy W.; Sakadžić, Sava

    2016-01-01

    Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These “bottom-up” models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

  9. The Pathway for Oxygen: Tutorial Modelling on Oxygen Transport from Air to Mitochondrion

    PubMed Central

    Bassingthwaighte, James B.; Raymond, Gary M.; Dash, Ranjan K.; Beard, Daniel A.; Nolan, Margaret

    2016-01-01

    The ‘Pathway for Oxygen’ is captured in a set of models describing quantitative relationships between fluxes and driving forces for the flux of oxygen from the external air source to the mitochondrial sink at cytochrome oxidase. The intervening processes involve convection, membrane permeation, diffusion of free and heme-bound O2 and enzymatic reactions. While this system’s basic elements are simple: ventilation, alveolar gas exchange with blood, circulation of the blood, perfusion of an organ, uptake by tissue, and consumption by chemical reaction, integration of these pieces quickly becomes complex. This complexity led us to construct a tutorial on the ideas and principles; these first PathwayO2 models are simple but quantitative and cover: 1) a ‘one-alveolus lung’ with airway resistance, lung volume compliance, 2) bidirectional transport of solute gasses like O2 and CO2, 3) gas exchange between alveolar air and lung capillary blood, 4) gas solubility in blood, and circulation of blood through the capillary syncytium and back to the lung, and 5) blood-tissue gas exchange in capillaries. These open-source models are at Physiome.org and provide background for the many respiratory models there. PMID:26782201

  10. Cellular therapy for haematological malignancies.

    PubMed

    Roddie, P H; Turner, M L

    2002-11-01

    The aim of this review was to summarize the recent progress made in the field of cellular therapeutics in haematological malignancy. The review also examined the role that the National Transfusion Services might play in the manufacture of new cellular therapeutic agents, given both their expertise in the safe provision of blood products and their possession of accredited cell manipulation facilities. Cellular therapy is entering an era in which novel cellular products will find increasing clinical use, particularly in the areas of haematopoietic stem cell transplantation and immunotherapy. The production of novel cell-based therapies, both in Europe and North America, is now under strict regulatory control and therefore collaboration with the National Transfusion Services in the manufacture of these agents may well be beneficial if the production standards demanded by the regulatory authorities are to be fulfilled. PMID:12437515

  11. [Haematological adverse effects caused by psychiatric drugs].

    PubMed

    Mazaira, Silvina

    2008-01-01

    Almost all clases of psychiatric drugs (typical and atypical antipsychotics, antidepressants, mood stabilizers, benzodiazepines) have been reported as possible causes of haematological toxicity. This is a review of the literature in which different clinical situations involving red blood cells, white blood cells, platelets and impaired coagulation are detailed and the drugs more frequently involved are listed. The haematological adverse reactions detailed here include: aplastic anemia, haemolitic anemia, leukopenia, agranulocytosis, leukocytosis, eosinophilia, thrombocytosis, thrombocytopenia, disordered platelet function and impaired coagulation. The haematologic toxicity profile of the drugs more frequently involved: lithium, clozapine, carbamazepine, valproic acid and SSRI antidepressants is mentioned. PMID:19424521

  12. Effect of sepsis on skeletal muscle oxygen consumption and tissue oxygenation: interpreting capillary oxygen transport data using a mathematical model.

    PubMed

    Goldman, Daniel; Bateman, Ryon M; Ellis, Christopher G

    2004-12-01

    Inherent in the inflammatory response to sepsis is abnormal microvascular perfusion. Maldistribution of capillary red blood cell (RBC) flow in rat skeletal muscle has been characterized by increased 1) stopped-flow capillaries, 2) capillary oxygen extraction, and 3) ratio of fast-flow to normal-flow capillaries. On the basis of experimental data for functional capillary density (FCD), RBC velocity, and hemoglobin O2 saturation during sepsis, a mathematical model was used to calculate tissue O2 consumption (Vo2), tissue Po2 (Pt) profiles, and O2 delivery by fast-flow capillaries, which could not be measured experimentally. The model describes coupled capillary and tissue O2 transport using realistic blood and tissue biophysics and three-dimensional arrays of heterogeneously spaced capillaries and was solved numerically using a previously validated scheme. While total blood flow was maintained, capillary flow distribution was varied from 60/30/10% (normal/fast/stopped) in control to 33/33/33% (normal/fast/stopped) in average sepsis (AS) and 25/25/50% (normal/fast/stopped) in extreme sepsis (ES). Simulations found approximately two- and fourfold increases in tissue Vo2 in AS and ES, respectively. Average (minimum) Pt decreased from 43 (40) mmHg in control to 34 (27) and 26 (15) mmHg in AS and ES, respectively, and clustering fast-flow capillaries (increased flow heterogeneity) reduced minimum Pt to 14.5 mmHg. Thus, although fast capillaries prevented tissue dysoxia, they did not prevent increased hypoxia as the degree of microvascular injury increased. The model predicts that decreased FCD, increased fast flow, and increased Vo2 in sepsis expose skeletal muscle to significant regions of hypoxia, which could affect local cellular and organ function. PMID:15319199

  13. Modelling the effects of cerebral microvasculature morphology on oxygen transport

    PubMed Central

    Park, Chang Sub; Payne, Stephen J.

    2016-01-01

    The cerebral microvasculature plays a vital role in adequately supplying blood to the brain. Determining the health of the cerebral microvasculature is important during pathological conditions, such as stroke and dementia. Recent studies have shown the complex relationship between cerebral metabolic rate and transit time distribution, the transit times of all the possible pathways available dependent on network topology. In this paper, we extend a recently developed technique to solve for residue function, the amount of tracer left in the vasculature at any time, and transit time distribution in an existing model of the cerebral microvasculature to calculate cerebral metabolism. We present the mathematical theory needed to solve for oxygen concentration followed by results of the simulations. It is found that oxygen extraction fraction, the fraction of oxygen removed from the blood in the capillary network by the tissue, and cerebral metabolic rate are dependent on both mean and heterogeneity of the transit time distribution. For changes in cerebral blood flow, a positive correlation can be observed between mean transit time and oxygen extraction fraction, and a negative correlation between mean transit time and metabolic rate of oxygen. A negative correlation can also be observed between transit time heterogeneity and the metabolic rate of oxygen for a constant cerebral blood flow. A sensitivity analysis on the mean and heterogeneity of the transit time distribution was able to quantify their respective contributions to oxygen extraction fraction and metabolic rate of oxygen. Mean transit time has a greater contribution than the heterogeneity for oxygen extraction fraction. This is found to be opposite for metabolic rate of oxygen. These results provide information on the role of the cerebral microvasculature and its effects on flow and metabolism. They thus open up the possibility of obtaining additional valuable clinical information for diagnosing and treating

  14. Impact of microstructure on oxygen semi-permeation performance of perovskite membranes: Understanding of oxygen transport mechanisms

    NASA Astrophysics Data System (ADS)

    Reichmann, M.; Geffroy, P.-M.; Richet, N.; Chartier, T.

    2016-08-01

    The influence of dense membrane microstructures on semi permeation performance is still not well understood, and no consensus or explanation can be established from the literature. The apparent discrepancy is likely due to a poor understanding of the oxygen transport mechanisms through the membrane and, specifically, to the impact of the microstructure on the oxygen surface exchange kinetics. The aim of this paper is to provide a better understanding of the impact of microstructures on oxygen transport mechanisms through the membrane. Two reference materials, Ba0.5Sr0.5Fe0.7Co0.3O3 (BSFCo) and La0.5Sr0.5Fe0.7Ga0.3O3 (LSFG) perovskites, are considered to explain the discrepancies observed in the literature.

  15. 49 CFR 175.34 - Exceptions for cylinders of compressed oxygen or other oxidizing gases transported within the...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Exceptions for cylinders of compressed oxygen or... Exceptions for cylinders of compressed oxygen or other oxidizing gases transported within the State of Alaska. (a) Exceptions. When transported in the State of Alaska, cylinders of compressed oxygen or...

  16. Seasonal variations of haematological parameters in athletes.

    PubMed

    Banfi, Giuseppe; Lundby, Carsten; Robach, Paul; Lippi, Giuseppe

    2011-01-01

    The influence of training and competition workloads is crucial for evaluation of longitudinal haematological data in athletes. There are only a few papers on the variation of haematological parameters during long-lasting periods and, especially, during an entire competitive season. We summarized that some haematological parameters can be influenced by long-term training and competition periods. Haemoglobin (Hb) and haematocrit (Ht) are decreased during the more intense periods of training, throughout the season. In different sport disciplines, the decline of Hb ranges from 3 to 8% during the competition season, while the range of reticulocytes (Ret%) varies from 5 to 21%. Reticulocytes are also decreased after long periods of training and competitions, but their variation is not necessarily associated with that of Hb. The qualitative variations (trend of modifications) of haematological parameters are roughly independent of the sport discipline, but quantitatively (amount of modifications) dependent on sport discipline. The modifications are more evident in cycling, running, swimming than they are in football and rugby. The variations of haematological parameters within the same sport discipline are qualitatively concordant and quantitatively different among separate but consecutive competitive seasons. These findings are described in aerobic and team sports sportsmen. The definition of reliable reference ranges in sportsmen would only be possible by following the best laboratory practices. For antidoping purposes more studies investigating haematological modifications during the season are advisable. PMID:20842374

  17. PSYCHOLOGICAL ASPECTS OF HAEMATOLOGICAL MALIGNANCIES

    PubMed Central

    Kulhara, P.; Verma, S.C.; Bambery, P.; Nehra, R.

    1990-01-01

    SUMMMARY Sixty nine patients with various types of haematological malignancies were studied. Chronic myeloid leukaemia (n =32) was the commonest diagnosis. The patients were assessed on Hamilton Rating Scale for Depression, PGI-N2 Health Questionnaire and Presumptive Stressful Life Events Scale and those who had scores above the cut off points for Hamilton Rating Scale and/or PGI-N2 Health Questionnaire were assessed on Present State Examination. The patients were followed up at 3 and 6 months interval. At 3 months 51 patients were re-assessed whilst at 6 months only 26 could be re-evaluated. There were no significant changes in scores of Hamilton Rating scale and PGI-N2 Health Questionnaire at intake and subsequent follow-up assessments. No significant correlations between stressful life experience and severity of illness emerged. Twenty nine patients were interviewed on Present State Examination and of these 20 had diagnosable depressive neuroses- From consultation liaison psychiatric point of view, provision of psychiatric help to these patients is discussed. PMID:21927472

  18. Experimental study of dissolved oxygen transport by regular waves through a perforated breakwater

    NASA Astrophysics Data System (ADS)

    Yin, Zegao; Yu, Ning; Liang, Bingchen; Zeng, Jixiong; Xie, Shaohua

    2016-02-01

    The perforated breakwater is an environmentally friendly coastal structure, and dissolved oxygen concentration levels are an important index to denote water quality. In this paper, oxygen transport experiments with regular waves through a vertical perforated breakwater were conducted. The oxygen scavenger method was used to reduce the dissolved oxygen concentration of inner water body with the chemicals Na2SO3 and CoCl2. The dissolved oxygen concentration and wave parameters of 36 experimental scenarios were measured with different perforated arrangements and wave conditions. It was found that the oxygen transfer coefficient through wave surface, K1 a 1, is much lower than the oxygen transport coefficient through the perforated breakwater, K2 a 2. If the effect of K1 a 1 is not considered, the dissolved oxygen concentration computation for inner water body will not be greatly affected. Considering the effect of a permeable area ratio a, relative location parameter of perforations δ and wave period T, the aforementioned data of 30 experimental scenarios, the dimensional analysis and the least squares method were used to derive an equation of K2 a 2 (K2 a 2=0.0042 a 0.5 δ 0.2 T -1). It was validated with 6 other experimental scenarios data, which indicates an approximate agreement. Therefore, this equation can be used to compute the DO concentration caused by the water transport through perforated breakwater.

  19. Bacterial swimming and oxygen transport near contact lines

    NASA Astrophysics Data System (ADS)

    Tuval, Idan; Cisneros, Luis; Dombrowski, Christopher; Wolgemuth, Charles W.; Kessler, John O.; Goldstein, Raymond E.

    2005-02-01

    Aerobic bacteria often live in thin fluid layers near solid-air-water contact lines, in which the biology of chemotaxis, metabolism, and cell-cell signaling is intimately connected to the physics of buoyancy, diffusion, and mixing. Using the geometry of a sessile drop, we demonstrate in suspensions of Bacillus subtilis the self-organized generation of a persistent hydrodynamic vortex that traps cells near the contact line. Arising from upward oxygentaxis and downward gravitational forcing, these dynamics are related to the Boycott effect in sedimentation and are explained quantitatively by a mathematical model consisting of oxygen diffusion and consumption, chemotaxis, and viscous fluid dynamics. The vortex is shown to advectively enhance uptake of oxygen into the suspension, and the wedge geometry leads to a singularity in the chemotactic dynamics near the contact line. bioconvection | chemotaxis | singularity | Bacillus subtilis

  20. Concepts of oxygen transport at the microcirculatory level.

    PubMed

    Dewhirst, M W

    1998-07-01

    This article compares and contrasts the classic paradigms underlying the development of chronic and acute hypoxia in tumors. The classic theory of Thomlinson and Gray suggested that chronic hypoxia is the result of large intravascular distances. Newer evidence suggests that a multiplicity of effects contribute to this process, including steep longitudinal gradients of partial pressure of oxygen (Po2) along the vascular tree before arteriolar entry into tumor, rheologic effects on red cell deformability brought on by intravascular hypoxia, uneven distribution of red cell fluxes in microvessels leading to plasma channels, irregular vascular geometry, and oxygen demand that is out of balance with the supply. The most common theories have suggested that vascular stasis is the most common source of acute hypoxia. If this were true, the incidence of this form of hypoxia would be relatively rare because most studies indicate that total stasis probably occurs less than 5% of the time. Studies have suggested, however, that spontaneous fluctuation in tumor blood flow, on the microregional level, can lead to tissue hypoxia, and total vascular stasis is not required. Spontaneous fluctuations in flow and Po2 appear to occur commonly. Thus, the most current evidence suggests that tumor oxygenation is in a continuous state of flux. Collectively, this new information has important implications for therapy resistance and gene expression. PMID:9634491

  1. Thermodynamic, transport, and flow properties of gaseous products resulting from combustion of methane-air-oxygen

    NASA Technical Reports Server (NTRS)

    Klich, G. F.

    1976-01-01

    Results of calculations to determine thermodynamic, transport, and flow properties of combustion product gases are presented. The product gases are those resulting from combustion of methane-air-oxygen and methane-oxygen mixtures. The oxygen content of products resulting from the combustion of methane-air-oxygen mixtures was similiar to that of air; however, the oxygen contained in products of methane-oxygen combustion ranged from 20 percent by volume to zero for stoichiometric combustion. Calculations were made for products of reactant mixtures with fuel percentages, by mass, of 7.5 to 20. Results are presented for specific mixtures for a range of pressures varying from 0.0001 to 1,000 atm and for temperatures ranging from 200 to 3,800 K.

  2. A compartmental model for oxygen-carbon dioxide coupled transport in the microcirculation.

    PubMed

    Ye, G F; Moore, T W; Buerk, D G; Jaron, D

    1994-01-01

    We present a multicompartmental model for an oxygen-carbon dioxide transport system. The compartmental equations and their lumped parameters are derived through space averaging of the corresponding distributed model. The model can predict compartmental distributions of oxygen and carbon dioxide partial pressures, oxygen-hemoglobin saturation, and pH. Other unique features include the effects of the radial distribution of partial pressures and the difference in metabolic rates between vessel wall and tissue. A model for the cat brain, based on this formulation, is compared with results of experiments and with two types of earlier models: one without space averaging and one without carbon dioxide transport. The results suggest that space averaging the convective terms significantly affects the behavior of the model. This is consistent with conclusions from our earlier oxygen-only model. Our observations also demonstrate, however, significant differences between the results from the oxygen-carbon dioxide model and the oxygen-only model. For instance, at low blood flow rates or at low level of oxygen input, predicted oxygen partial pressures can differ by as much as 30% between the two models. Results obtained from the present model are supported by available experimental findings. PMID:7825749

  3. Membrane Transport of Singlet Oxygen Monitored by Dipole Potential Measurements

    PubMed Central

    Sokolov, Valerij S.; Pohl, Peter

    2009-01-01

    Abstract The efficiency of photodynamic reactions depends on 1), the penetration depth of the photosensitizer into the membrane and 2), the sidedness of the target. Molecules which are susceptible to singlet oxygen (1O2) experience less damage when separated from the photosensitizer by the membrane. Since 1O2 lifetime in the membrane environment is orders of magnitude longer than the time required for nonexcited oxygen (O2) to cross the membrane, this observation suggests that differences between the permeabilities or membrane partition of 1O2 and O2 exist. We investigated this hypothesis by releasing 1O2 at one side of a planar membrane while monitoring the kinetics of target damage at the opposite side of the same membrane. Damage to the target, represented by dipole-modifying molecules (phloretin or phlorizin), was indicated by changes in the interleaflet dipole potential difference Δϕb. A simple analytical model allowed estimation of the 1O2 interleaflet concentration difference from the rate at which Δϕb changed. It confirmed that the lower limit of 1O2 permeability is ∼2 cm/s; i.e., it roughly matches O2 permeability as predicted by Overton's rule. Consequently, the membrane cannot act as a barrier to 1O2 diffusion. Differences in the reaction rates at the cytoplasmic and extracellular membrane leaflets may be attributed only to 1O2 quenchers inside the membrane. PMID:18931253

  4. Plant hemoglobins: a molecular fossil record for the evolution of oxygen transport.

    PubMed

    Hoy, Julie A; Robinson, Howard; Trent, James T; Kakar, Smita; Smagghe, Benoit J; Hargrove, Mark S

    2007-08-01

    The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport "leghemoglobins" evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins. PMID:17560601

  5. Plant Hemoglobins: A Molecular Fossil Record for the Evolutin of Oxygen Transport

    SciTech Connect

    Hoy,J.; Robinson, H.; Trent, lll, J.; Kakar, S.; Smagghe, B.; Hargrove, M.

    2007-01-01

    The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport 'leghemoglobins' evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins.

  6. Oxygen transport deficits in systemic disease and implications for physical therapy.

    PubMed

    Dean, E

    1997-02-01

    The purposes of this article are to discuss the effects of some common systemic diseases on cardiopulmonary function and oxygen transport and to describe the implications for physical therapists. Pathology of every major organ system can manifest secondary effects on cardiopulmonary function and oxygen transport. Such effects are of considerable clinical significance given that they can be life threatening and that physical therapy usually stresses the oxygen transport system. This article reviews the cardiopulmonary effects of hematologic, neuromuscular, musculoskeletal, gastrointestinal, hepatic, renal, collagen vascular and connective tissue, endocrine, and immunologic conditions. The cardiopulmonary manifestations of some common nutritional disorders (eg, obesity, anorexia nervosa) are also discussed. Physical therapists need to be able to anticipate, detect, and manage the cardiopulmonary manifestations of systemic disease given medical advances and the increasing number of patients with multisystem problems, the aging of the population, the expanding scope of physical therapy practice, and the increased professional and ethical responsibility associated with direct patient access. PMID:9037219

  7. A dynamic model of oxygen transport from capillaries to tissue with moving red blood cells.

    PubMed

    Lücker, Adrien; Weber, Bruno; Jenny, Patrick

    2015-02-01

    Most oxygen required to support the energy needs of vertebrate tissues is delivered by diffusion from microvessels. The presence of red blood cells (RBCs) makes blood flow in the microcirculation highly heterogeneous. Additionally, flow regulation mechanisms dynamically respond to changes in tissue energy demand. These spatiotemporal variations directly affect the supply of oxygen to parenchymal cells. Due to various limiting assumptions, current models of oxygen transport cannot fully capture the consequences of complex hemodynamic effects on tissue oxygenation and are often not suitable for studying unsteady phenomena. With our new approach based on moving RBCs, the impact of blood flow heterogeneity on oxygen partial pressure (Po2) in the tissue can be quantified. Oxygen transport was simulated using parachute-shaped solid RBCs flowing through a capillary. With the use of a conical tissue domain with radii 19 and 13 μm, respectively, our computations indicate that Po2 at the RBC membrane exceeds Po2 between RBCs by 30 mmHg on average and that the mean plasma Po2 decreases by 9 mmHg over 50 μm. These results reproduce well recent intravascular Po2 measurements in the rodent brain. We also demonstrate that instantaneous variations of capillary hematocrit cause associated fluctuations of tissue Po2. Furthermore, our results suggest that homogeneous tissue oxygenation requires capillary networks to be denser on venular side than on arteriolar side. Our new model for oxygen transport will make it possible to quantify in detail the effects of blood flow heterogeneity on tissue oxygenation in realistic capillary networks. PMID:25398979

  8. A computational model of oxygen transport in the cerebrocapillary levels for normal and pathologic brain function

    PubMed Central

    Safaeian, Navid; David, Tim

    2013-01-01

    The oxygen exchange and correlation between the cerebral blood flow (CBF) and cerebral metabolic rate of oxygen consumption (CMRO2) in the cortical capillary levels for normal and pathologic brain functions remain the subject of debate. A 3D realistic mesoscale model of the cortical capillary network (non-tree like) is constructed using a random Voronoi tessellation in which each edge represents a capillary segment. The hemodynamics and oxygen transport are numerically simulated in the model, which involves rheological laws in the capillaries, oxygen diffusion, and non-linear binding of oxygen to hemoglobin, respectively. The findings show that the cerebral hypoxia due to a significant decreased perfusion (as can occur in stroke) can be avoided by a moderate reduction in oxygen demand. Oxygen extraction fraction (OEF) can be an important indicator for the brain oxygen metabolism under normal perfusion and misery-perfusion syndrome (leading to ischemia). The results demonstrated that a disproportionately large increase in blood supply is required for a small increase in the oxygen demand, which, in turn, is strongly dependent on the resting OEF. The predicted flow-metabolism coupling in the model supports the experimental studies of spatiotemporal stimulations in humans by positron emission tomography and functional magnetic resonance imaging. PMID:23921901

  9. [Massage and sophrology workshops for haematology professionals].

    PubMed

    Bannier, Christine; Sachot, Claudine; Simon, Armelle

    2014-04-01

    In haematology, the caregivers are confronted with the death of patients and the distress of their families. It is a working environment in which it is essential for the professionals to be taken care of in order to optimise the care provided to patients. At Nantes general hospital, massage and sophrology workshops enable the caregivers to recharge their batteries. PMID:24881242

  10. Erythropoiesis-stimulating agents and other methods to enhance oxygen transport.

    PubMed

    Elliott, S

    2008-06-01

    Oxygen is essential for life, and the body has developed an exquisite method to collect oxygen in the lungs and transport it to the tissues. Hb contained within red blood cells (RBCs), is the key oxygen-carrying component in blood, and levels of RBCs are tightly controlled according to demand for oxygen. The availability of oxygen plays a critical role in athletic performance, and agents that enhance oxygen delivery to tissues increase aerobic power. Early methods to increase oxygen delivery included training at altitude, and later, transfusion of packed RBCs. A breakthrough in understanding how RBC formation is controlled included the discovery of erythropoietin (Epo) and cloning of the EPO gene. Cloning of the EPO gene was followed by commercial development of recombinant human Epo (rHuEpo). Legitimate use of this and other agents that affect oxygen delivery is important in the treatment of anaemia (low Hb levels) in patients with chronic kidney disease or in cancer patients with chemotherapy-induced anaemia. However, competitive sports was affected by illicit use of rHuEpo to enhance performance. Testing methods for these agents resulted in a cat-and-mouse game, with testing labs attempting to detect the use of a drug or blood product to improve athletic performance (doping) and certain athletes developing methods to use the agents without being detected. This article examines the current methods to enhance aerobic performance and the methods to detect illicit use. PMID:18362898

  11. Assessing the performance of reactant transport layers and flow fields towards oxygen transport: A new imaging method based on chemiluminescence

    NASA Astrophysics Data System (ADS)

    Lopes, Thiago; Ho, Matthew; Kakati, Biraj K.; Kucernak, Anthony R. J.

    2015-01-01

    A new, simple and precise ex-situ optical imaging method is developed which allows indirect measurement of the partial pressure of oxygen (as ozone) within fuel cell components. Images of oxygen distribution are recorded with higher spatial (∼20 μm) and time (40 ms) resolutions. This approach is applied to assess oxygen concentration across the face of a pseudo polymer electrolyte fuel cell (PEFC), with a serpentine design flow field. We show that the amount of light produced is directly proportional to the partial pressure of ozone, in the same way as the local current density in a PEFC is proportional to the partial pressure of bimolecular oxygen. Hence the simulated system provides information relevant to a PEFC with the same geometry operating at the same stoichiometric ratio. This new approach allows direct imaging of flow under lands due to pressure gradients between the adjacent channels and non-laminar flow effects due to secondary flow around U-turns. These are major discoveries of fundamental importance in guiding materials development and in validating modelling studies. We find that contrary to many simulation papers, advection is an important mechanism in both the gas diffusion layer (more properly "reactant transport layer") and the microporous layer. Models which do not include these effects may underestimate reactant transport to the catalyst layer.

  12. Automated haematology analysis to diagnose malaria

    PubMed Central

    2010-01-01

    For more than a decade, flow cytometry-based automated haematology analysers have been studied for malaria diagnosis. Although current haematology analysers are not specifically designed to detect malaria-related abnormalities, most studies have found sensitivities that comply with WHO malaria-diagnostic guidelines, i.e. ≥ 95% in samples with > 100 parasites/μl. Establishing a correct and early malaria diagnosis is a prerequisite for an adequate treatment and to minimizing adverse outcomes. Expert light microscopy remains the 'gold standard' for malaria diagnosis in most clinical settings. However, it requires an explicit request from clinicians and has variable accuracy. Malaria diagnosis with flow cytometry-based haematology analysers could become an important adjuvant diagnostic tool in the routine laboratory work-up of febrile patients in or returning from malaria-endemic regions. Haematology analysers so far studied for malaria diagnosis are the Cell-Dyn®, Coulter® GEN·S and LH 750, and the Sysmex XE-2100® analysers. For Cell-Dyn analysers, abnormal depolarization events mainly in the lobularity/granularity and other scatter-plots, and various reticulocyte abnormalities have shown overall sensitivities and specificities of 49% to 97% and 61% to 100%, respectively. For the Coulter analysers, a 'malaria factor' using the monocyte and lymphocyte size standard deviations obtained by impedance detection has shown overall sensitivities and specificities of 82% to 98% and 72% to 94%, respectively. For the XE-2100, abnormal patterns in the DIFF, WBC/BASO, and RET-EXT scatter-plots, and pseudoeosinophilia and other abnormal haematological variables have been described, and multivariate diagnostic models have been designed with overall sensitivities and specificities of 86% to 97% and 81% to 98%, respectively. The accuracy for malaria diagnosis may vary according to species, parasite load, immunity and clinical context where the method is applied. Future

  13. Effect of nitric oxide on the transport and release of oxygen in fetal blood.

    PubMed

    Clementi, Maria Elisabetta; Orsini, Federica; Schininà, Maria Eugenia; Noia, Giuseppe; Giardina, Bruno

    2003-03-14

    It is well known that nitric oxide (NO), the most important vasodilator agent, plays an important role in lowering vascular resistance in the human umbilical-placental circulation and that its deficiency is related to the pathogenesis of pre-eclamptic disorder. Besides it has recently been demonstrated that human hemoglobin (HbA) is able to transport nitric oxide, as S-nitrosohemoglobin (SNO-Hb), from the arterial to the venous blood. In the present study we examine the functional properties of the adult and fetal nitrosated hemoglobins to see if the double transport of oxygen and NO may influence the fetal oxygenation and the relation between maternal and fetal blood. Our results show that S-nitrosation significantly increases the oxygen affinity of the adult Hb (HbA) with respect to native protein (no-nitrosated) while the functional properties of HbF are less influenced. The oxygen affinity modification, found for SNO-HbA, was ascribed to the nitrosation of cysteine beta 93: really, the same residue is also present in the gamma chains of fetal hemoglobin, while the increase of affinity is less evidenced; hence, it is probable that the 39 aminoacidic substitutions between beta and gamma chains allay the effects of S-nitrosation. As regards the physiological modulators (protons, chloride ions, 2,3-diphosphoglyceric acid, and temperature), they influence the oxygen affinity of the two hemoglobins S-nitrosated, in equal mode with respect to the native forms determining the same variation on the oxygen affinity. Hence, our results evidence the fact that the NO release by SNO-HbA "in vivo" would be limited to regions of extremely low oxygen tension (such as hypoxic regions), while in fetus, SNO-HbF would unload nitric oxide and oxygen at pressure values close to normal. PMID:12615064

  14. Cancer stem cells in haematological malignancies

    PubMed Central

    Golab, Jakub

    2015-01-01

    At least several types of human haematological malignancies can now be seen as ‘stem-cell diseases’. The best-studied in this context is acute myeloid leukaemia (AML). It has been shown that these diseases are driven by a pool of ‘leukaemia stem cells (LSC)’, which remain in the quiescent state, have the capacity to survive and self-renew, and are responsible for the recurrence of cancer after classical chemotherapy. It has been understood that LSC must be eliminated in order to cure patients suffering from haematological cancers. Recent advances in LSC research have allowed for description of LSC phenotype and identification of potential targets for anti-LSC therapies. This concise review summarises the current view on LSC biology and targeted approaches against LSC. PMID:25691816

  15. Pressure dependence of the oxygen reduction reaction at the platinum microelectrode/nafion interface - Electrode kinetics and mass transport

    NASA Technical Reports Server (NTRS)

    Parthasarathy, Arvind; Srinivasan, Supramaniam; Appleby, A. J.; Martin, Charles R.

    1992-01-01

    The investigation of oxygen reduction kinetics at the platinum/Nafion interface is of great importance in the advancement of proton-exchange-membrane (PEM) fuel-cell technology. This study focuses on the dependence of the oxygen reduction kinetics on oxygen pressure. Conventional Tafel analysis of the data shows that the reaction order with respect to oxygen is unity at both high and low current densities. Chronoamperometric measurements of the transport parameters for oxygen in Nafion show that oxygen dissolution follows Henry's isotherm. The diffusion coefficient of oxygen is invariant with pressure; however, the diffusion coefficient for oxygen is lower when air is used as the equilibrating gas as compared to when oxygen is used for equilibration. These results are of value in understanding the influence of O2 partial pressure on the performance of PEM fuel cells and also in elucidating the mechanism of oxygen reduction at the platinum/Nafion interface.

  16. Role of tumour angiogenesis in haematological malignancies.

    PubMed

    Medinger, Michael; Passweg, Jakob

    2014-01-01

    Tumour angiogenesis plays a key role in the pathogenesis and progression of haematological malignancies. Thereby, pro- and anti-angiogenic growth factors and cytokines regulate the angiogenic process. The most important growth factor, vascular endothelial growth factor (VEGF) and its signaling through its receptors 1 and 2, is not only involved in solid tumours, but there is also emerging evidence that tumour progression in haematological malignancies also depends on the induction of new blood vessel formation. The evidence supporting this theory includes the finding of increased bone marrow microvessel density and increased levels of plasma pro-angiogenic cytokines. Leukaemia cells interact with surrounding host cells and extracellular matrix, this crosstalk affecting the most important aspects of the malignant phenotype. The pathophysiology of leukaemia induced angiogenesis involves both direct production of angiogenic cytokines by leukaemia cells and their interaction with bone marrow microenvironment. The inhibition of VEGF signalling by monoclonal antibodies or small molecules (kinase inhibitors) has already been successfully used for the treatment of different cancer entities, and multiple new drugs are being tested. This review summarises recent advances in the basic understanding of the role of angiogenesis in haematological malignancies and the translation of such basic findings into clinical studies. PMID:25375891

  17. [Toward pertinent analytical objectives for haematological parameters].

    PubMed

    Iobagiu, Cristina; Nehar, Diane; Denis, Isabelle; de Saint-Trivier, Aurélie; Boyer, Michelle

    2014-01-01

    Usually, the blood cell counting activity in haematology laboratory uses the comparison of IQC values to the target values proposed by the manufacturer. We intended to improve the monitoring of the proper functioning of our analytical measure system for 17 main haematologic parameters. To set the allowable critical limits of IQC, we propose our reflection based on several elements: benchmark and expert recommendation, clinical requirements, statistical indicators of the laboratory calculated using IQC values (3 levels, 2 different lots, 2 haematology analysers and 2 passage modes) and the EEQ values, during four months. We exploited the reports obtained from the middleware (our own IQC values), and the interlaboratory comparison reports (obtained from SNCS and EuroCell websites) and we compared our performances to the Ricos objectives, to set clearly argued allowable limits for IQC values. Finally, the allowable limits correspond to the imprecision limits stated by Ricos for 14 parameters (desirable for 11 parametres and minimal for 3 parameters) and personalized limits (more exigent than desirable Ricos limits) for 3 parameters of blood cell counting. PMID:25486666

  18. Sex differences in circulatory oxygen transport parameters of sockeye salmon (Oncorhynchus nerka) on the spawning ground.

    PubMed

    Clark, Timothy Darren; Hinch, S G; Taylor, B D; Frappell, P B; Farrell, A P

    2009-07-01

    Upon reaching sexual maturity, several species of male salmonids possess a relative ventricular mass (rM(V)) that may be up to 90% larger than females. This can increase maximum cardiac stroke volume and power output, which may be beneficial to increasing the oxygen transport capacity of male salmonids during the spawning period. It may be further hypothesized, therefore, that other variables within the circulatory oxygen transport cascade, such as blood oxygen-carrying capacity and heart rate, are similarly enhanced in reproductively mature male salmonids. To test this idea, the present study measured a range of circulatory oxygen transport variables in wild male and female sockeye salmon (Oncorhynchus nerka) during their spawning period, following a 150 km migration from the ocean. The rM(V) of male fish was 13% greater than females. Conversely, the haemoglobin concentration ([Hb]) of female fish was 19% higher than males, indicative of a greater blood oxygen-carrying capacity (138 vs. 116 ml O2 l(-1), respectively). Surgically implanted physiological data loggers revealed a similar range in heart rate for both sexes on the spawning ground (20-80 beats min(-1) at 10 degrees C), with a tendency for male fish to spend a greater percentage of time (64%) than females (49%) at heart rates above 50 beats min(-1). Male fish on average consumed significantly more oxygen than females during a 13-h respirometry period. However, routine oxygen consumption rates (.)MO2 ranged between 1.5 and 8.5 mg min(-1) kg(-1) for both sexes, which implies that males did not inherently possess markedly higher routine aerobic energy demands, and suggests that the higher [Hb] of female fish may compensate for the smaller rM(V). These findings reject the hypothesis that all aspects of the circulatory oxygen transport cascade are inherently superior in male sockeye salmon. Instead, it is suggested that any differences in (.)MO2 between sexually mature male and female sockeye salmon can likely

  19. Oxygen transport in the internal xenon plasma of a dispenser hollow cathode

    SciTech Connect

    Capece, Angela M. Shepherd, Joseph E.; Polk, James E.; Mikellides, Ioannis G.

    2014-04-21

    Reactive gases such as oxygen and water vapor modify the surface morphology of BaO dispenser cathodes and degrade the electron emission properties. For vacuum cathodes operating at fixed temperature, the emission current drops rapidly when oxygen adsorbs on top of the low work function surface. Previous experiments have shown that plasma cathodes are more resistant to oxygen poisoning and can operate with O{sub 2} partial pressures one to two orders of magnitude higher than vacuum cathodes before the onset of poisoning occurs. Plasma cathodes used for electric thrusters are typically operated with xenon; however, gas phase barium, oxygen, and tungsten species may be found in small concentrations. The densities of these minor species are small compared with the plasma density, and thus, their presence in the discharge does not significantly alter the xenon plasma parameters. It is important, however, to consider the transport of these minor species as they may deposit on the emitter surface and affect the electron emission properties. In this work, we present the results of a material transport model used to predict oxygen fluxes to the cathode surface by solving the species conservation equations in a cathode with a 2.25 mm diameter orifice operated at a discharge current of 15 A, a Xe flow rate of 3.7 sccm, and 100 ppm of O{sub 2}. The dominant ionization process for O{sub 2} is resonant charge exchange with xenon ions. Ba is effectively recycled in the plasma; however, BaO and O{sub 2} are not. The model shows that the oxygen flux to the surface is not diffusion-limited; therefore, the high resistance to oxygen poisoning observed in plasma cathodes likely results from surface processes not considered here.

  20. Oxygen transport in the internal xenon plasma of a dispenser hollow cathode

    NASA Astrophysics Data System (ADS)

    Capece, Angela M.; Polk, James E.; Mikellides, Ioannis G.; Shepherd, Joseph E.

    2014-04-01

    Reactive gases such as oxygen and water vapor modify the surface morphology of BaO dispenser cathodes and degrade the electron emission properties. For vacuum cathodes operating at fixed temperature, the emission current drops rapidly when oxygen adsorbs on top of the low work function surface. Previous experiments have shown that plasma cathodes are more resistant to oxygen poisoning and can operate with O2 partial pressures one to two orders of magnitude higher than vacuum cathodes before the onset of poisoning occurs. Plasma cathodes used for electric thrusters are typically operated with xenon; however, gas phase barium, oxygen, and tungsten species may be found in small concentrations. The densities of these minor species are small compared with the plasma density, and thus, their presence in the discharge does not significantly alter the xenon plasma parameters. It is important, however, to consider the transport of these minor species as they may deposit on the emitter surface and affect the electron emission properties. In this work, we present the results of a material transport model used to predict oxygen fluxes to the cathode surface by solving the species conservation equations in a cathode with a 2.25 mm diameter orifice operated at a discharge current of 15 A, a Xe flow rate of 3.7 sccm, and 100 ppm of O2. The dominant ionization process for O2 is resonant charge exchange with xenon ions. Ba is effectively recycled in the plasma; however, BaO and O2 are not. The model shows that the oxygen flux to the surface is not diffusion-limited; therefore, the high resistance to oxygen poisoning observed in plasma cathodes likely results from surface processes not considered here.

  1. Oxygen isotopic transport and exchange during fluid flow: One-dimensional models and applications

    SciTech Connect

    Bowman, J.R. ); Willett, S.D. ); Cook, S.J. Environ Corp., Houston, TX )

    1994-01-01

    In this work the authors investigate the consequences of fluid flow and fluid-rock interaction to the isotopic evolution of fluids and rock with one-dimensional transport models of fluid flow and oxygen isotope exchange. Transport models dealing with stable isotopes are well established in recent geochemical literature. The authors extend previous treatments by presenting the derivation of both analytical and numerical solutions to the transport equations incorporating simultaneously advection, diffusion and hydrodynamic dispersion, and kinetics of isotopic exchange. The increased generality of numerical solutions allows the incorporation of other effects which control the spatial patterns of [delta][sup 18]O values developed in rocks and fluids including multiple reactive species and temperature gradients. The authors discuss the effects of flow parameters, conditions of isotopic exchange, and temperature gradients on the spatial patterns of isotopic shifts produced in rock sequences subjected to fluid flow, and on conventionally calculated W/R ratios for these rock sequences. Finally, the authors examine the implications of oxygen isotope transport for two natural systems where isotopic shifts or gradients could be interpreted in terms of unidirectional fluid infiltration. Solutions of one-dimensional transport equations including the mechanisms of advection, diffusion, hydrodynamic dispersion, and non-equilibrium exchange between water and rock indicate that the time-space evolution of oxygen isotopic compositions of rock and infiltrating fluid is dependent on (1) the rate of fluid infiltration, (2) the diffusive and dispersive properties of the rock matrix, (3) the rate of isotopic exchange, and (4) the rock-water mass oxygen ratio in a unit volume of water-saturated, porous rock. 56 refs., 18 figs., 2 tabs.

  2. Numerical simulation of oxygen transport during the CZ silicon crystal growth process

    NASA Astrophysics Data System (ADS)

    Chen, Jyh-Chen; Teng, Ying-Yang; Wun, Wan-Ting; Lu, Chung-Wei; Chen, Hsueh-I.; Chen, Chi-Yung; Lan, Wen-Chieh

    2011-03-01

    In this study, the effect of the flow motion and heat transfer generated by the crystal and crucible rotation on the oxygen distribution inside the melt during Czochralski silicon crystal growth is investigated. When the crucible rotates in a direction opposite to the crystal rotation, Taylor-Proundman vortices appear in the region below the crystal. The diffusion of oxygen impurity from the crucible wall to the crystal-melt interface is suppressed by these Taylor-Proundman vortices, while heat transport from the crucible wall to the crystal-melt interface is blocked by the Taylor-Proundman vortices. With a higher crucible rotation rate, the size of the Taylor-Proundman vortices increases and the size of the buoyancy-thermocapillary vortices decreases. This causes the temperature at the crucible wall to rise and the evaporation of oxygen impurity on the free surface to decrease. Hence, the amount of oxygen impurity that diffuses into the melt towards the crystal-melt interface increases. The suppression from the Taylor-Proundman vortices is dominant for the smaller crucible rotation rate, while the enhancement from the oxygen impurity diffusion prevails for the higher crucible rotation rate. Therefore, there is an optimum combination of crucible and crystal rotation for obtaining the lowest oxygen concentration.

  3. Bench-to-bedside review: Microvascular dysfunction in sepsis –hemodynamics, oxygen transport, and nitric oxide

    PubMed Central

    Bateman, Ryon M; Sharpe, Michael D; Ellis, Christopher G

    2003-01-01

    The microcirculation is a complex and integrated system that supplies and distributes oxygen throughout the tissues. The red blood cell (RBC) facilitates convective oxygen transport via co-operative binding with hemoglobin. In the microcirculation oxygen diffuses from the RBC into neighboring tissues, where it is consumed by mitochondria. Evidence suggests that the RBC acts as deliverer of oxygen and 'sensor' of local oxygen gradients. Within vascular beds RBCs are distributed actively by arteriolar tone and passively by rheologic factors, including vessel geometry and RBC deformability. Microvascular oxygen transport is determined by microvascular geometry, hemodynamics, and RBC hemoglobin oxygen saturation. Sepsis causes abnormal microvascular oxygen transport as significant numbers of capillaries stop flowing and the microcirculation fails to compensate for decreased functional capillary density. The resulting maldistribution of RBC flow results in a mismatch of oxygen delivery with oxygen demand that affects both critical oxygen delivery and oxygen extraction ratio. Nitric oxide (NO) maintains microvascular homeostasis by regulating arteriolar tone, RBC deformability, leukocyte and platelet adhesion to endothelial cells, and blood volume. NO also regulates mitochondrial respiration. During sepsis, NO over-production mediates systemic hypotension and microvascular reactivity, and is seemingly protective of microvascular blood flow. PMID:12974969

  4. Enhancing oxygen transport through Mixed-Ionic-and-Electronic-Conducting ceramic membranes

    NASA Astrophysics Data System (ADS)

    Yu, Anthony S.

    Ceramic membranes based on Mixed-Ionic-and-Electronic-Conducting (MIEC) oxides are capable of separating oxygen from air in the presence of an oxygen partial-pressure gradient. These MIEC membranes show great promise for oxygen consuming industrial processes, such as the production of syngas from steam reforming of natural gas (SRM), as well as for electricity generation in Solid Oxide Fuel Cells (SOFC). For both applications, the overall performance is dictated by the rate of oxygen transport across the membrane. Oxygen transport across MIEC membranes is composed of a bulk oxygen-ion diffusion process and surface processes, such as surface reactions and adsorption/desorption of gaseous reactants/products. The main goal of this thesis was to determine which process is rate-limiting in order to significantly enhance the overall rate of oxygen transport in MIEC membrane systems. The rate-limiting step was determined by evaluating the total resistance to oxygen transfer, Rtot. Rtot is the sum of a bulk diffusion resistance in the membrane itself, Rb, and interfacial loss components, Rs. Rb is a function of the membrane's ionic conductivity and thickness, while Rs arises primarily from slow surface-exchange kinetics that cause the P(O2) at the surfaces of the membrane to differ from the P(O 2) in the adjacent gas phases. Rtot can be calculated from the Nernst potential across the membrane and the measured oxygen flux. The rate-limiting process can be determined by evaluating the relative contributions of the various losses, Rs and Rb, to Rtot. Using this method, this thesis demonstrates that for most membrane systems, Rs is the dominating factor. In the development of membrane systems with high oxygen transport rates, thin membranes with high ionic conductivities are required to achieve fast bulk oxygen-ion diffusion. However, as membrane thickness is decreased, surface reaction kinetics become more important in determining the overall transport rate. The two

  5. O2 and CO2 glow-discharge-assisted oxygen transport through Ag

    NASA Astrophysics Data System (ADS)

    Outlaw, R. A.

    1990-08-01

    The permeation of oxygen through Ag normally occurs by a sequence of steps which include the initial dissociative adsorption of molecular oxygen at the upstream surface, the dissolution of the atoms into the bulk, and the subsequent migration of the atoms between octahedral sites of the lattice until they arrive at the vacuum interface downstream. The dissociative adsorption step, however, proceeds slowly, as indicated by the low sticking coefficient of O2 on Ag(10-6-10-3). The application of a dc field in 0.5 Torr of O2 (E/n˜10-14 V cm2) on the upstream side of a Ag membrane generated gas phase atomic oxygen that substantially enhanced the transport. The transport flux was observed to increase from a value of 4.4×1013 cm-2 s-1 to a glow discharge value of 2.83×1014 cm-2 s-1 at a membrane temperature of 650 °C. This suggests that the dissociative adsorption step limits the supply of oxygen atoms to the upstream side of the membrane. When the upstream O2 was replaced by an equal pressure of CO2, only a small permeation signal was observed, but the application of the glow discharge substantially increased the transport flux from 3.25×1012 cm-2 s-1 to 1.74×1014 cm-2 s-1. This method of separating O2 from a CO2 environment may be a possible mechanism for providing a supply of oxygen for astronauts in a manned mission to Mars.

  6. The effect of mechanical twisting on oxygen ionic transport in solid-state energy conversion membranes

    NASA Astrophysics Data System (ADS)

    Shi, Yanuo; Bork, Alexander Hansen; Schweiger, Sebastian; Rupp, Jennifer Lilia Marguerite

    2015-07-01

    Understanding `electro-chemo-mechanics’ in oxygen ion conducting membranes represents a foundational step towards new energy devices such as micro fuel cells and oxygen or fuel separation membranes. For ionic transport in macro crystalline electrolytes, doping is conventionally used to affect oxygen ionic association/migration energies. Recently, tuning ionic transport in films through lattice strain conveyed by substrates or heterostructures has generated much interest. However, reliable manipulation of strain states to twist the ionic conduction in real micro energy devices remains intractable. Here, we demonstrate that the oxygen ionic conductivity clearly correlates with the compressive strain energy acting on the near order of the electrolyte lattices by comparing thin-film ceria-based membrane devices against substrate-supported flat structures. It is possible to capitalize on this phenomenon with a smart choice of strain patterns achieved through microelectrode design. We highlight the importance of electro-chemo-mechanics in the electrolyte material for the next generation of solid-state energy conversion microdevices.

  7. Oxygen transport in perovskite-type solid oxide fuel cell materials: insights from quantum mechanics.

    PubMed

    Muñoz-García, Ana B; Ritzmann, Andrew M; Pavone, Michele; Keith, John A; Carter, Emily A

    2014-11-18

    CONSPECTUS: Global advances in industrialization are precipitating increasingly rapid consumption of fossil fuel resources and heightened levels of atmospheric CO2. World sustainability requires viable sources of renewable energy and its efficient use. First-principles quantum mechanics (QM) studies can help guide developments in energy technologies by characterizing complex material properties and predicting reaction mechanisms at the atomic scale. QM can provide unbiased, qualitative guidelines for experimentally tailoring materials for energy applications. This Account primarily reviews our recent QM studies of electrode materials for solid oxide fuel cells (SOFCs), a promising technology for clean, efficient power generation. SOFCs presently must operate at very high temperatures to allow transport of oxygen ions and electrons through solid-state electrolytes and electrodes. High temperatures, however, engender slow startup times and accelerate material degradation. SOFC technologies need cathode and anode materials that function well at lower temperatures, which have been realized with mixed ion-electron conductor (MIEC) materials. Unfortunately, the complexity of MIECs has inhibited the rational tailoring of improved SOFC materials. Here, we gather theoretically obtained insights into oxygen ion conductivity in two classes of perovskite-type materials for SOFC applications: the conventional La1-xSrxMO3 family (M = Cr, Mn, Fe, Co) and the new, promising class of Sr2Fe2-xMoxO6 materials. Using density functional theory + U (DFT+U) with U-J values obtained from ab initio theory, we have characterized the accompanying electronic structures for the two processes that govern ionic diffusion in these materials: (i) oxygen vacancy formation and (ii) vacancy-mediated oxygen migration. We show how the corresponding macroscopic oxygen diffusion coefficient can be accurately obtained in terms of microscopic quantities calculated with first-principles QM. We find that the

  8. Synergy between shear-induced migration and secondary flows on red blood cells transport in arteries: considerations on oxygen transport.

    PubMed

    Biasetti, Jacopo; Spazzini, Pier Giorgio; Hedin, Ulf; Gasser, T Christian

    2014-08-01

    Shear-induced migration of red blood cells (RBCs) is a well-known phenomenon characterizing blood flow in the small vessels (micrometre to millimetre size) of the cardiovascular system. In large vessels, like the abdominal aorta and the carotid artery (millimetre to centimetre size), the extent of this migration and its interaction with secondary flows has not been fully elucidated. RBC migration exerts its influence primarily on platelet concentration, oxygen transport and oxygen availability at the luminal surface, which could influence vessel wall disease processes in and adjacent to the intima. Phillips' shear-induced particle migration model, coupled to the Quemada viscosity model, was employed to simulate the macroscopic behaviour of RBCs in four patient-specific geometries: a normal abdominal aorta, an abdominal aortic aneurysm (AAA), a normal carotid bifurcation and a stenotic carotid bifurcation. Simulations show a migration of RBCs from the near-wall region with a lowering of wall haematocrit (volume fraction of RBCs) on the posterior side of the normal aorta and on the lateral-external side of the iliac arteries. A marked migration is observed on the outer wall of the carotid sinus, along the common carotid artery and in the carotid stenosis. No significant migration is observed in the AAA. The spatial and temporal patterns of wall haematocrit are correlated with the near-wall shear layer and with the secondary flows induced by the vessel curvature. In particular, secondary flows accentuate the initial lowering in RBC near-wall concentration by convecting RBCs from the inner curvature side to the outer curvature side. The results reinforce data in literature showing a decrease in oxygen partial pressure on the inner curvature wall of the carotid sinus induced by the presence of secondary flows. The lowering of wall haematocrit is postulated to induce a decrease in oxygen availability at the luminal surface through a diminished concentration of

  9. Synergy between shear-induced migration and secondary flows on red blood cells transport in arteries: considerations on oxygen transport

    PubMed Central

    Biasetti, Jacopo; Spazzini, Pier Giorgio; Hedin, Ulf; Gasser, T. Christian

    2014-01-01

    Shear-induced migration of red blood cells (RBCs) is a well-known phenomenon characterizing blood flow in the small vessels (micrometre to millimetre size) of the cardiovascular system. In large vessels, like the abdominal aorta and the carotid artery (millimetre to centimetre size), the extent of this migration and its interaction with secondary flows has not been fully elucidated. RBC migration exerts its influence primarily on platelet concentration, oxygen transport and oxygen availability at the luminal surface, which could influence vessel wall disease processes in and adjacent to the intima. Phillips' shear-induced particle migration model, coupled to the Quemada viscosity model, was employed to simulate the macroscopic behaviour of RBCs in four patient-specific geometries: a normal abdominal aorta, an abdominal aortic aneurysm (AAA), a normal carotid bifurcation and a stenotic carotid bifurcation. Simulations show a migration of RBCs from the near-wall region with a lowering of wall haematocrit (volume fraction of RBCs) on the posterior side of the normal aorta and on the lateral-external side of the iliac arteries. A marked migration is observed on the outer wall of the carotid sinus, along the common carotid artery and in the carotid stenosis. No significant migration is observed in the AAA. The spatial and temporal patterns of wall haematocrit are correlated with the near-wall shear layer and with the secondary flows induced by the vessel curvature. In particular, secondary flows accentuate the initial lowering in RBC near-wall concentration by convecting RBCs from the inner curvature side to the outer curvature side. The results reinforce data in literature showing a decrease in oxygen partial pressure on the inner curvature wall of the carotid sinus induced by the presence of secondary flows. The lowering of wall haematocrit is postulated to induce a decrease in oxygen availability at the luminal surface through a diminished concentration of

  10. Role of reactive oxygen species in regulation of glucose transport in skeletal muscle during exercise.

    PubMed

    Katz, Abram

    2016-06-01

    Glucose derived from extracellular sources serves as an energy source in virtually all eukaryotic cells, including skeletal muscle. Its contribution to energy turnover increases with exercise intensity up to moderately heavy workloads. However, at very high workloads, the contribution of extracellular glucose to energy turnover is negligible, despite the high rate of glucose transport. Reactive oxygen species (ROS) are involved in the stimulation of glucose transport in isolated skeletal muscle preparations during intense repeated contractions. Consistent with this observation, heavy exercise is associated with significant production of ROS. However, during more mild to moderate stimulation or exercise conditions (in vitro, in situ and in vivo) antioxidants do not affect glucose transport. It is noteworthy that the production of ROS is limited or not observed under these conditions and that the concentration of the antioxidant used was extremely low. The results to date suggest that ROS involvement in activation of glucose transport occurs primarily during intense short-term exercise and that other mechanisms are involved during mild to moderate exercise. What remains puzzling is why ROS-mediated activation of glucose transport would occur under conditions where glucose transport is highest and utilization (i.e. phosphorylation of glucose by hexokinase) is low. Possibly ROS production is involved in priming glucose transport during heavy exercise to accelerate glycogen biogenesis during the initial recovery period after exercise, as well as altering other aspects of intracellular metabolism. PMID:26791627

  11. Simulation of oxygen carrier mediated oxygen transport to C3A hepatoma cells housed within a hollow fiber bioreactor.

    PubMed

    Sullivan, Jesse P; Gordon, Jason E; Palmer, Andre F

    2006-02-01

    A priori knowledge of the dissolved oxygen (O2) concentration profile within a hepatic hollow fiber (HF) bioreactor is important in developing an effective bioartificial liver assist device (BLAD). O2 provision is limiting within HF bioreactors and we hypothesize that supplementing a hepatic HF bioreactor's circulating media with bovine red blood cells (bRBCs), which function as an O2 carrier, will improve oxygenation. The dissolved O2 concentration profile within a single HF (lumen, membrane, and representative extra capillary space (ECS)) was modeled with the finite element method, and compared to experimentally measured data obtained on an actual HF bioreactor with the same dimensions housing C3A hepatoma cells. Our results (experimental and modeling) indicate bRBC supplementation of the circulating media leads to an increase in O2 consumed by C3A cells. Under certain experimental conditions (pO2,IN) = 95 mmHg, Q = 8.30 mL/min), the addition of bRBCs at 5% of the average in vivo human red blood cell concentration (% hRBC) results in approximately 50% increase in the O2 consumption rate (OCR). By simply adjusting the operating conditions (pO2,IN) = 25 mmHg, Q = 1.77 mL/min) and increasing bRBC concentration to 25% hRBC the OCR increase is approximately 10-fold. However, the improved O2 concentration profile experienced by the C3A cells could not duplicate the full range of in vivo O2 tensions (25-70 mmHg) typically experienced within the liver sinusoid with this particular HF bioreactor. Nonetheless, we demonstrate that the O2 transport model accurately predicts O2 consumption within a HF bioreactor, thus setting up the modeling framework for improving the design of future hepatic HF bioreactors. PMID:16161160

  12. Study of the oxygen transport through Ag (110), Ag (poly), and Ag 2.0 Zr

    NASA Technical Reports Server (NTRS)

    Outlaw, R. A.; Wu, D.; Davidson, M. R.; Hoflund, Gar B.

    1992-01-01

    The transport of oxygen through high-purity membranes of Ag (110), Ag (poly), Ag (nano), and Ag 2.0 Zr has been studied by an ultrahigh vacuum permeation method over the temperature range of 400-800 C. The data show that there are substantial deviations from ordinary diffusion-controlled transport. A surface limitation has been confirmed by glow-discharge studies where the upstream O2 supply has been partially converted to atoms, which, for the same temperature and pressure, gave rise to over an order of magnitude increase in transport flux. Further, the addition of 2.0 wt percent Zr to the Ag has provided increased dissociative adsorption rates, which, in turn, increased the transport flux by a factor of 2. It was also observed that below a temperature of 630 C, the diffusivity exhibits an increase in activation energy of over 4 kcal/mol, which has been attributed to trapping of the atomic oxygen and/or kinetic barriers at the surface and subsurface of the vacuum interface. Above 630 C, the activation barrier decreases to the accepted value of about 11 kcal/mol for Ag (poly), consistent with zero concentration at the vacuum interface.

  13. Hazardous Off-Gassing of Carbon Monoxide and Oxygen Depletion during Ocean Transportation of Wood Pellets

    PubMed Central

    Svedberg, Urban; Samuelsson, Jerker; Melin, Staffan

    2008-01-01

    Five ocean vessels were investigated for the characterization and quantification of gaseous compounds emitted during ocean transportation of wood pellets in closed cargo hatches from Canada to Sweden. The study was initiated after a fatal accident with several injured during discharge in Sweden. The objective with the investigation was to better understand the off-gassing and issues related to workers' exposure. Air sampling was done during transport and immediately before discharge in the undisturbed headspace air above the wood pellets and in the staircase adjacent to each hatch. The samples were analyzed with Fourier transform infrared spectroscopy and direct reading instruments. The following compounds and ranges were detected in samples from the five ships: carbon monoxide (CO) 1460–14650 ppm, carbon dioxide (CO2) 2960–21570 ppm, methane 79.9–956 ppm, butane equivalents 63–842 ppm, ethylene 2–21.2 ppm, propylene 5.3–36 ppm, ethane 0–25 ppm and aldehydes 2.3–35 ppm. The oxygen levels were between 0.8 and 16.9%. The concentrations in the staircases were almost as high as in the cargo hatches, indicating a fairly free passage of air between the two spaces. A potentially dangerous atmosphere was reached within a week from loading. The conclusions are that ocean transportation of wood pellets in confined spaces may produce an oxygen deficient atmosphere and lethal levels of CO which may leak into adjacent access spaces. The dangerous combination of extremely high levels of CO and reduced oxygen produces a fast-acting toxic combination. Measurement of CO in combination with oxygen is essential prior to entry in spaces having air communication with cargo hatches of wood pellets. Forced ventilation of staircases prior to entry is necessary. Redesign, locking and labeling of access doors and the establishment of rigorous entry procedures and training of onboard crew as well as personnel boarding ocean vessels are also important. PMID:18397907

  14. Impact of renal medullary three-dimensional architecture on oxygen transport.

    PubMed

    Fry, Brendan C; Edwards, Aurélie; Sgouralis, Ioannis; Layton, Anita T

    2014-08-01

    We have developed a highly detailed mathematical model of solute transport in the renal medulla of the rat kidney to study the impact of the structured organization of nephrons and vessels revealed in anatomic studies. The model represents the arrangement of tubules around a vascular bundle in the outer medulla and around a collecting duct cluster in the upper inner medulla. Model simulations yield marked gradients in intrabundle and interbundle interstitial fluid oxygen tension (PO2), NaCl concentration, and osmolality in the outer medulla, owing to the vigorous active reabsorption of NaCl by the thick ascending limbs. In the inner medulla, where the thin ascending limbs do not mediate significant active NaCl transport, interstitial fluid composition becomes much more homogeneous with respect to NaCl, urea, and osmolality. Nonetheless, a substantial PO2 gradient remains, owing to the relatively high oxygen demand of the inner medullary collecting ducts. Perhaps more importantly, the model predicts that in the absence of the three-dimensional medullary architecture, oxygen delivery to the inner medulla would drastically decrease, with the terminal inner medulla nearly completely deprived of oxygen. Thus model results suggest that the functional role of the three-dimensional medullary architecture may be to preserve oxygen delivery to the papilla. Additionally, a simulation that represents low medullary blood flow suggests that the separation of thick limbs from the vascular bundles substantially increases the risk of the segments to hypoxic injury. When nephrons and vessels are more homogeneously distributed, luminal PO2 in the thick ascending limb of superficial nephrons increases by 66% in the inner stripe. Furthermore, simulations predict that owing to the Bohr effect, the presumed greater acidity of blood in the interbundle regions, where thick ascending limbs are located, relative to that in the vascular bundles, facilitates the delivery of O2 to support the

  15. Constraints on oceanic meridional heat transport from combined measurements of oxygen and carbon

    NASA Astrophysics Data System (ADS)

    Resplandy, L.; Keeling, R. F.; Stephens, B. B.; Bent, J. D.; Jacobson, A.; Rödenbeck, C.; Khatiwala, S.

    2016-02-01

    Despite its importance to the climate system, the ocean meridional heat transport is still poorly quantified. We identify a strong link between the northern hemisphere deficit in atmospheric potential oxygen (APO = O_2 + 1.1 × CO_2 ) and the asymmetry in meridional heat transport between northern and southern hemispheres. The recent aircraft observations from the HIPPO campaign reveal a northern APO deficit in the tropospheric column of - 10.4 ± 1.0 per meg, double the value at the surface and more representative of large-scale air-sea fluxes. The global northward ocean heat transport asymmetry necessary to explain the observed APO deficit is about 0.7-1.1 PW, which corresponds to the upper range of estimates from hydrographic sections and atmospheric reanalyses.

  16. Pediatric Extracorporeal Membrane Oxygenation Transport by EC-145 With a Custom-Built Sled.

    PubMed

    Holt, Philip L; Hodge, Ashley B; Ratliff, Todd; Frazier, W Joshua; Ohnesorge, David; Gee, Samantha W

    2016-01-01

    Indications for the use of extracorporeal membrane oxygenation (ECMO) in pediatrics has expanded beyond the initial historic treatment of neonates with respiratory failure. Patients with severe refractory cardiopulmonary failure may benefit from ECMO support until the primary insult has subsided or been treated. More recently, ECMO has been used by some centers as a bridge to transplant for irreversible organ failure. Nationwide Children's Hospital is a referral center that supports the use of ECMO as a bridge to transplant and is able to provide transport services for ECMO patients referred for transplant evaluation. In this report, we describe our design of a unique, custom-built sled designed specifically for the EC-145 helicopter to transport pediatric ECMO patients to our institution. This report is the first, to our knowledge, to describe the safe and successful transport of a pediatric ECMO patient in an EC-145 helicopter. PMID:27255881

  17. Membrane transporters mediating root signalling and adaptive responses to oxygen deprivation and soil flooding.

    PubMed

    Shabala, Sergey; Shabala, Lana; Barcelo, Juan; Poschenrieder, Charlotte

    2014-10-01

    This review provides a comprehensive assessment of a previously unexplored topic: elucidating the role that plasma- and organelle-based membrane transporters play in plant-adaptive responses to flooding. We show that energy availability and metabolic shifts under hypoxia and anoxia are critical in regulating membrane-transport activity. We illustrate the high tissue and time dependence of this regulation, reveal the molecular identity of transporters involved and discuss the modes of their regulation. We show that both reduced oxygen availability and accumulation of transition metals in flooded roots result in a reduction in the cytosolic K(+) pool, ultimately determining the cell's fate and transition to programmed cell death (PCD). This process can be strongly affected by hypoxia-induced changes in the amino acid pool profile and, specifically, ϒ-amino butyric acid (GABA) accumulation. It is suggested that GABA plays an important regulatory role, allowing plants to proceed with H2 O2 signalling to activate a cascade of genes that mediate plant adaptation to flooding while at the same time, preventing the cell from entering a 'suicide program'. We conclude that progress in crop breeding for flooding tolerance can only be achieved by pyramiding the numerous physiological traits that confer efficient energy maintenance, cytosolic ion homeostasis, and reactive oxygen species (ROS) control and detoxification. PMID:24689809

  18. Gas Transport Resistance in Polymer Electrolyte Thin Films on Oxygen Reduction Reaction Catalysts.

    PubMed

    Liu, Hang; Epting, William K; Litster, Shawn

    2015-09-15

    Significant reductions in expensive platinum catalyst loading for the oxygen reduction reaction are needed for commercially viable fuel cell electric vehicles as well as other important applications. In reducing loading, a resistance at the Pt surface in the presence of thin perfluorosulfonic acid (PFSA) electrolyte film, on the order of 10 nm thick, becomes a significant barrier to adequate performance. However, the resistance mechanism is unresolved and could be due to gas dissolution kinetics, increased diffusion resistance in thin films, or electrolyte anion interactions. A common hypothesis for the origin of the resistance is a highly reduced oxygen permeability in the thin polymer electrolyte films that coat the catalyst relative to bulk permeability that is caused by nanoscale confinement effects. Unfortunately, the prior work has not separated the thin-film gas transport resistance from that associated with PFSA interactions with a polarized catalyst surface. Here, we present the first characterization of the thin-film O2 transport resistance in the absence of a polarized catalyst, using a nanoporous substrate that geometrically mimics the active catalyst particles. Through a parametric study of varying PFSA film thickness, as thin as 50 nm, we observe no enhanced gas transport resistance in thin films as a result of either interfacial effects or structural changes in the PFSA. Our results suggest that other effects, such as anion poisoning at the Pt catalyst, could be the source of the additional resistance observed at low Pt loading. PMID:26299282

  19. Modelling the oxygen cost of transport in competitions over ground of variable slope.

    PubMed

    Schroter, R C; Marlin, D J

    2002-09-01

    This study provides an objective method for estimating the oxygen consumption of horses while running on variable slopes so that realistic comparisons may be made of the locomotory transport cost involved in 3-day events, particularly the Speed and Endurance Test, at sites of differing terrain. A knowledge of the work profile over a particular course would enable competitors to plan speed and interval times appropriately along its length. We have developed a semi-empirical, but mechanistically based, model to calculate the oxygen cost of transport [COTpath in ml O2/kg/m path] for running on the flat, up or down a slope of given gradient (from -0.3 to +0.3). The model is then used to calculate the overall effort of running on a number of 3-day event courses of differing standard; the model does not assess the energetic cost of jumping. The cost of transport over the range of gradient of -0.3 to +0.3 was modelled using the following equations: On the flat or uphill: COTpath = 0.123 + 1.561(gradient); Downhill: COTpath = 0.123 + 1.591(gradient) + 9.762(gradient)2 + 14.0(gradient)3. PMID:12405723

  20. Diffusive flux in a model of stochastically gated oxygen transport in insect respiration

    NASA Astrophysics Data System (ADS)

    Berezhkovskii, Alexander M.; Shvartsman, Stanislav Y.

    2016-05-01

    Oxygen delivery to insect tissues is controlled by transport through a branched tubular network that is connected to the atmosphere by valve-like gates, known as spiracles. In certain physiological regimes, the spiracles appear to be randomly switching between open and closed states. Quantitative analysis of this regime leads a reaction-diffusion problem with stochastically switching boundary condition. We derive an expression for the diffusive flux at long times in this problem. Our approach starts with the derivation of the passage probability for a single particle that diffuses between a stochastically gated boundary, which models the opening and closing spiracle, and the perfectly absorbing boundary, which models oxygen absorption by the tissue. This passage probability is then used to derive an expression giving the diffusive flux as a function of the geometric parameters of the tube and characteristic time scales of diffusion and gate dynamics.

  1. Diffusive flux in a model of stochastically gated oxygen transport in insect respiration.

    PubMed

    Berezhkovskii, Alexander M; Shvartsman, Stanislav Y

    2016-05-28

    Oxygen delivery to insect tissues is controlled by transport through a branched tubular network that is connected to the atmosphere by valve-like gates, known as spiracles. In certain physiological regimes, the spiracles appear to be randomly switching between open and closed states. Quantitative analysis of this regime leads a reaction-diffusion problem with stochastically switching boundary condition. We derive an expression for the diffusive flux at long times in this problem. Our approach starts with the derivation of the passage probability for a single particle that diffuses between a stochastically gated boundary, which models the opening and closing spiracle, and the perfectly absorbing boundary, which models oxygen absorption by the tissue. This passage probability is then used to derive an expression giving the diffusive flux as a function of the geometric parameters of the tube and characteristic time scales of diffusion and gate dynamics. PMID:27250273

  2. Oxygen transport pathways in Ruddlesden–Popper structured oxides revealed via in situ neutron diffraction

    DOE PAGESBeta

    Tomkiewicz, Alex C.; Tamimi, Mazin; Huq, Ashfia; McIntosh, Steven

    2015-09-21

    Ruddlesden-Popper structured oxides, general form An+1BnO3n+1, consist of n-layers of the perovskite structure stacked in between rock-salt layers, and have potential application in solid oxide electrochemical cells and ion transport membrane reactors. Three materials with constant Co/Fe ratio, LaSrCo0.5Fe0.5O4-δ (n = 1), La0.3Sr2.7CoFeO7-δ (n = 2), and LaSr3Co1.5Fe1.5O10-δ (n = 3) were synthesized and studied via in situ neutron powder diffraction between 765 K and 1070 K at a pO2 of 10-1 atm. Then, the structures were fit to a tetragonal I4/mmm space group, and were found to have increased total oxygen vacancy concentration in the order La0.3Sr2.7CoFeO7-δ > LaSr3Co1.5Fe1.5O10-δmore » > LaSrCo0.5Fe0.5O4-δ, following the trend predicted for charge compensation upon increasing Sr2+/La3+ ratio. The oxygen vacancies within the material were almost exclusively located within the perovskite layers for all of the crystal structures with only minimal vacancy formation in the rock-salt layer. Finally, analysis of the concentration of these vacancies at each distinct crystallographic site and the anisotropic atomic displacement parameters for the oxygen sites reveals potential preferred oxygen transport pathways through the perovskite layers.« less

  3. Oxygen transport through polyethylene terephthalate (PET) coated with plasma-polymerized acetylene at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Wemlinger, Erik; Pedrow, Patrick; Garcia-Pérez, Manuel; Sablani, Shyam

    2011-10-01

    Moser et al. have shown that oxygen transport through polyethyleneterephthalate (PET) is reduced by a factor of up to 120 when, at reduced pressure, hydrogenated amorphous carbon film with thickness less than 100 nm is applied to the PET substrate. Our work includes using atmospheric pressure cold plasma to grow a plasma-polymerized acetylene film on PET substrate and measuring reductions in oxygen transport. The reactor utilizes corona discharges and is operated at 60 Hz with a maximum voltage of 10 kV RMS. Corona streamers emanate from an array of needles with an average radius of curvature of 50 μm. The reactor utilizes a cylindrical reaction chamber with a vertical orientation such that argon carrier gas and acetylene precursor gas are introduced at the top then pass through the cold plasma activation zone and then through a grounded stainless steel mesh. Acetylene radicals are incident on the PET substrate and form plasma-polymerized acetylene film. Moser et al. have shown that oxygen transport through polyethyleneterephthalate (PET) is reduced by a factor of up to 120 when, at reduced pressure, hydrogenated amorphous carbon film with thickness less than 100 nm is applied to the PET substrate. Our work includes using atmospheric pressure cold plasma to grow a plasma-polymerized acetylene film on PET substrate and measuring reductions in oxygen transport. The reactor utilizes corona discharges and is operated at 60 Hz with a maximum voltage of 10 kV RMS. Corona streamers emanate from an array of needles with an average radius of curvature of 50 μm. The reactor utilizes a cylindrical reaction chamber with a vertical orientation such that argon carrier gas and acetylene precursor gas are introduced at the top then pass through the cold plasma activation zone and then through a grounded stainless steel mesh. Acetylene radicals are incident on the PET substrate and form plasma-polymerized acetylene film. E.M. Moser, R. Urech, E. Hack, H. Künzli, E. Müller, Thin

  4. Comparison of automated haematology analysers for detection of apoptotic lymphocytes.

    PubMed

    Taga, K; Sawaya, M; Yoshida, M; Kaneko, M; Okada, M; Taniho, M

    2002-06-01

    Automated haematology analysers can rapidly provide accurate blood cell counts and white blood cell differentials. In this study, we evaluated four different haematology analysers for the detection of apoptotic lymphocytes in peripheral blood: MAXM A/L Retic, H*2, Cell-Dyn 3500 and NE-8000. With the MAXM A/L Retic haematology analyser, the apoptotic lymphocyte cluster appeared below the original lymphocyte cluster on the volume/DF1, and to the right under the original lymphocyte cluster on the volume/DF2 scattergrams. With the H*2 haematology analyser, the apoptotic polymorphonuclear lymphocytes produced a higher lobularity index on the BASO channel. With the Cell-Dyn 3500 haematology analyser, the apoptotic lymphocyte cluster appeared to the right side of the original lymphocyte cluster on the 0D/10D scattergram and to the left side of the polymorphonuclear cluster on the 90D/10D scattergram. With the NE-8000 haematology analyser, the apoptotic lymphocyte cluster was not distinguishable. Thus, apoptotic lymphocytes are readily detected on scattergrams generated by selected haematology analysers. PMID:12067276

  5. Oxygen transport and cardiovascular function at extreme altitude: lessons from Operation Everest II

    NASA Technical Reports Server (NTRS)

    Sutton, J. R.; Reeves, J. T.; Groves, B. M.; Wagner, P. D.; Alexander, J. K.; Hultgren, H. N.; Cymerman, A.; Houston, C. S.

    1992-01-01

    Operation Everest II was designed to examine the physiological responses to gradual decompression simulating an ascent of Mt Everest (8,848 m) to an inspired PO2 of 43 mmHg. The principal studies conducted were cardiovascular, respiratory, muscular-skeletal and metabolic responses to exercise. Eight healthy males aged 21-31 years began the "ascent" and six successfully reached the "summit", where their resting arterial blood gases were PO2 = 30 mmHg and PCO2 = 11 mmHg, pH = 7.56. Their maximal oxygen uptake decreased from 3.98 +/- 0.2 L/min at sea level to 1.17 +/- 0.08 L/min at PIO2 43 mmHg. The principal factors responsible for oxygen transport from the atmosphere to tissues were (1) Alveolar ventilation--a four fold increase. (2) Diffusion from the alveolus to end capillary blood--unchanged. (3) Cardiac function (assessed by hemodynamics, echocardiography and electrocardiography)--normal--although maximum cardiac output and heart rate were reduced. (4) Oxygen extraction--maximal with PvO2 14.8 +/- 1 mmHg. With increasing altitude maximal blood and muscle lactate progressively declined although at any submaximal intensity blood and muscle lactate was higher at higher altitudes.

  6. Oxygen transport properties estimation by classical trajectory-direct simulation Monte Carlo

    NASA Astrophysics Data System (ADS)

    Bruno, Domenico; Frezzotti, Aldo; Ghiroldi, Gian Pietro

    2015-05-01

    Coupling direct simulation Monte Carlo (DSMC) simulations with classical trajectory calculations is a powerful tool to improve predictive capabilities of computational dilute gas dynamics. The considerable increase in computational effort outlined in early applications of the method can be compensated by running simulations on massively parallel computers. In particular, Graphics Processing Unit acceleration has been found quite effective in reducing computing time of classical trajectory (CT)-DSMC simulations. The aim of the present work is to study dilute molecular oxygen flows by modeling binary collisions, in the rigid rotor approximation, through an accurate Potential Energy Surface (PES), obtained by molecular beams scattering. The PES accuracy is assessed by calculating molecular oxygen transport properties by different equilibrium and non-equilibrium CT-DSMC based simulations that provide close values of the transport properties. Comparisons with available experimental data are presented and discussed in the temperature range 300-900 K, where vibrational degrees of freedom are expected to play a limited (but not always negligible) role.

  7. Oxygen transport properties estimation by classical trajectory–direct simulation Monte Carlo

    SciTech Connect

    Bruno, Domenico; Frezzotti, Aldo Ghiroldi, Gian Pietro

    2015-05-15

    Coupling direct simulation Monte Carlo (DSMC) simulations with classical trajectory calculations is a powerful tool to improve predictive capabilities of computational dilute gas dynamics. The considerable increase in computational effort outlined in early applications of the method can be compensated by running simulations on massively parallel computers. In particular, Graphics Processing Unit acceleration has been found quite effective in reducing computing time of classical trajectory (CT)-DSMC simulations. The aim of the present work is to study dilute molecular oxygen flows by modeling binary collisions, in the rigid rotor approximation, through an accurate Potential Energy Surface (PES), obtained by molecular beams scattering. The PES accuracy is assessed by calculating molecular oxygen transport properties by different equilibrium and non-equilibrium CT-DSMC based simulations that provide close values of the transport properties. Comparisons with available experimental data are presented and discussed in the temperature range 300–900 K, where vibrational degrees of freedom are expected to play a limited (but not always negligible) role.

  8. Phenotype-environment association of the oxygen transport system in trimorphic European whitefish (Coregonus lavaretus) populations.

    PubMed

    Evans, Melissa L; Praebel, Kim; Peruzzi, Stefano; Amundsen, Per-Arne; Bernatchez, Louis

    2014-08-01

    Replicated adaptive radiation events, typified by phenotypic divergence across resource axes, provide important insight into the eco-evolutionary dynamics that lead to the formation of new species. Here, we show that in trimorphic adaptive radiations of European whitefish (Coregonus lavaretus), divergence of the oxygen transport system has occurred across the pelagic/littoral (shallow)-profundal (deep) resource axis, and at multiple biological scales. Profundal whitefish exhibited significantly larger red blood cells (RBCs), a greater proportion of cathodic hemoglobin protein components, and higher hemoglobin transcript abundance in kidney compared to littoral and pelagic morphs. Hemoglobin transcript abundance in brain and gill, but not kidney, and anodic hemoglobin protein component diversity in blood were also linked to variation at an intronic single nucleotide polymorphism (SNP). As the whitefish morphs differ in population genetic structure at this SNP, hemoglobin transcript and protein divergence between profundal and pelagic/littoral morphs is likely being driven by genetic divergence. Our findings, along with our previous work on lake whitefish, highlight the importance of the oxygen transport system to the postglacial colonization of novel lacustrine environments by whitefish throughout the northern hemisphere. PMID:24766154

  9. Modeling of ambient-meniscus melt interactions associated with carbon and oxygen transport in EFG of silicon ribbon

    SciTech Connect

    Kalejs, J.P.; Chin, L.Y.

    1982-06-01

    Impurity transport processes associated with interaction of reactive ambient gases and meniscus melt during growth of silicon ribbon by the edge-defined film-fed growth (EFG) technique have been investigated with the help of numerical solution of mass and momentum transport equations. The transport of oxygen and carbon is examined in detail. It is shown that oxygen transport from meniscus sources can account for the interstitial oxygen observed to be introduced into ribbon grown with Co/sub 2/ in the meniscus ambient. Growth speed is the process parameter that has the most pronounced influence on ribbon impurity levels when a source or sink for the impurity is present on the meniscus surface. 14 refs.

  10. Oxygen and carbon dioxide transport in time-dependent blood flow past fiber rectangular arrays

    NASA Astrophysics Data System (ADS)

    Zierenberg, Jennifer R.; Fujioka, Hideki; Hirschl, Ronald B.; Bartlett, Robert H.; Grotberg, James B.

    2009-03-01

    The influence of time-dependent flows on oxygen and carbon dioxide transport for blood flow past fiber arrays arranged in in-line and staggered configurations was computationally investigated as a model for an artificial lung. Both a pulsatile flow, which mimics the flow leaving the right heart and passing through a compliance chamber before entering the artificial lung, and a right ventricular flow, which mimics flow leaving the right heart and directly entering the artificial lung, were considered in addition to a steady flow. The pulsatile flow was modeled as a sinusoidal perturbation superimposed on a steady flow while the right ventricular flow was modeled to accurately depict the period of flow acceleration (increasing flow) and deceleration (decreasing flow) during systole followed by zero flow during diastole. It was observed that the pulsatile flow yielded similar gas transport as compared to the steady flow, while the right ventricular flow resulted in smaller gas transport, with the decrease increasing with Re. The pressure drop across the fiber array (a measure of the resistance), work (an indicator of the work required of the right heart), and shear stress (a measure of potential blood cell activation and damage) are lowest for steady flow, followed by pulsatile flow, and then right ventricular flow. The pressure drop, work, shear stress, and Sherwood numbers (a measure of the gas transport efficiency) decrease with increasing porosity and are smaller for AR <1 as compared to AR >1 (AR is the distance between fibers in the flow direction/distance between fibers in direction perpendicular to flow), although for small porosities the Sherwood numbers are of similar magnitude. In general, for any fiber array geometry, high pressure drop, work, and shear stresses correlate with high Sherwood numbers, and low pressure drop, work, and shear stresses correlate with low Sherwood numbers creating a need for a compromise between pressure drop/work/shear stresses

  11. Haematological cancer and quality of life: a systematic literature review.

    PubMed

    Allart-Vorelli, P; Porro, B; Baguet, F; Michel, A; Cousson-Gélie, F

    2015-01-01

    The aim of this study is to examine the impact of haematological cancers on quality of life (QoL). A review of the international literature was conducted from the databases 'PsycInfo' and 'Medline' using the keywords: 'haematological cancer', 'quality of life', 'physical', 'psychological', 'social', 'vocational', 'professional', 'economic', 'cognitive', and 'sexual'. Twenty-one reliable studies were analysed. Among these studies, 12 showed that haematological cancer altered overall QoL, 8 papers found a deterioration of physical dimension, 8 papers reported on functional and role dimensions, 11 papers reported on the psychological component and 9 on the social component. Moreover, one study and two manuscripts, respectively, reported deteriorated sexual and cognitive dimensions. Our review demonstrates that the different dimensions of QoL are deteriorated by haematological malignancies and, probably, by the side effects of treatment. PMID:25909835

  12. Haematological cancer and quality of life: a systematic literature review

    PubMed Central

    Allart-Vorelli, P; Porro, B; Baguet, F; Michel, A; Cousson-Gélie, F

    2015-01-01

    The aim of this study is to examine the impact of haematological cancers on quality of life (QoL). A review of the international literature was conducted from the databases ‘PsycInfo' and 'Medline' using the keywords: 'haematological cancer', 'quality of life', 'physical', 'psychological', 'social', 'vocational', 'professional', 'economic', 'cognitive', and 'sexual'. Twenty-one reliable studies were analysed. Among these studies, 12 showed that haematological cancer altered overall QoL, 8 papers found a deterioration of physical dimension, 8 papers reported on functional and role dimensions, 11 papers reported on the psychological component and 9 on the social component. Moreover, one study and two manuscripts, respectively, reported deteriorated sexual and cognitive dimensions. Our review demonstrates that the different dimensions of QoL are deteriorated by haematological malignancies and, probably, by the side effects of treatment. PMID:25909835

  13. Trial of Haploidentical Stem Cell Transplantation for Haematological Cancers

    ClinicalTrials.gov

    2015-12-07

    Hodgkin's Lymphoma; Non-Hodgkin's Lymphoma; Acute Myeloid Leukaemia; Acute Lymphoblastic Leukaemia; Myelodysplastic Syndrome; Chronic Myeloid Leukaemia; Chronic Lymphocytic Leukaemia; Acquired Bone Marrow Failure Syndromes; Other Haematological Malignancies; Unrelated HSCT Indicated

  14. Oxygen transport pathways in Ruddlesden–Popper structured oxides revealed via in situ neutron diffraction

    SciTech Connect

    Tomkiewicz, Alex C.; Tamimi, Mazin; Huq, Ashfia; McIntosh, Steven

    2015-09-21

    Ruddlesden-Popper structured oxides, general form An+1BnO3n+1, consist of n-layers of the perovskite structure stacked in between rock-salt layers, and have potential application in solid oxide electrochemical cells and ion transport membrane reactors. Three materials with constant Co/Fe ratio, LaSrCo0.5Fe0.5O4-δ (n = 1), La0.3Sr2.7CoFeO7-δ (n = 2), and LaSr3Co1.5Fe1.5O10-δ (n = 3) were synthesized and studied via in situ neutron powder diffraction between 765 K and 1070 K at a pO2 of 10-1 atm. Then, the structures were fit to a tetragonal I4/mmm space group, and were found to have increased total oxygen vacancy concentration in the order La0.3Sr2.7CoFeO7-δ > LaSr3Co1.5Fe1.5O10-δ > LaSrCo0.5Fe0.5O4-δ, following the trend predicted for charge compensation upon increasing Sr2+/La3+ ratio. The oxygen vacancies within the material were almost exclusively located within the perovskite layers for all of the crystal structures with only minimal vacancy formation in the rock-salt layer. Finally, analysis of the concentration of these vacancies at each distinct crystallographic site and the anisotropic atomic displacement parameters for the oxygen sites reveals potential preferred oxygen transport pathways through the perovskite layers.

  15. First experience with the ultra compact mobile extracorporeal membrane oxygenation system Cardiohelp in interhospital transport.

    PubMed

    Philipp, Alois; Arlt, Matthias; Amann, Matthias; Lunz, Dirk; Müller, Thomas; Hilker, Michael; Graf, Bernhard; Schmid, Christof

    2011-06-01

    In patients with severe cardiopulmonary failure extracorporeal assist devices are to support patients during resuscitation, for transportation, until organ recovery, and as bridge to further therapeutic modalities. We report on our first experience with the new Cardiohelp system for interhospital transfer of cardiopulmonarily compromised patients. The Cardiohelp system was used for transportation and in-house treatment in six male patients with a mean age of 41±17 years. Five patients suffered respiratory failure; one patient with acute myocardial infarction was in profound cardiogenic shock. Accordingly, the Cardiohelp system was implanted as a venovenous extracorporeal membrane oxygenation (ECMO) in five patients and as a venoarterial system in one patient. The preECMO ventilation time was 0.5-4 days. The patients were transported to our institution by car (n=1) or helicopter (n=5) over a distance of 80-5850 km. The subsequent in-house ECMO support was continued with the Cardiohelp and lasted for 5-13 days. PostECMO ventilation was one to 25 days. A 100% survival was achieved. The portable Cardiohelp system allows location-independent stabilization of cardiopulmonary compromised patients with consecutive interhospital transfer and in-house treatment. The integrated sensors, which register arterial and venous line pressure, blood temperature, hemoglobin as well as SvO(2), greatly alleviate its management and considerably increase safety. PMID:21388980

  16. Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures

    DOE PAGESBeta

    Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui; Chu, Ying-Hao; Kalinin, Sergei V.

    2015-08-27

    Development of new generation electronic devices requires understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation ofmore » the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite–cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Finally and furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching.« less

  17. Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures.

    PubMed

    Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui; Chu, Ying-Hao; Kalinin, Sergei V

    2015-10-14

    Development of new generation electronic devices necessitates understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation of the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite-cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching. PMID:26312554

  18. Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures

    SciTech Connect

    Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui; Chu, Ying-Hao; Kalinin, Sergei V.

    2015-08-27

    Development of new generation electronic devices requires understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation of the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite–cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Finally and furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching.

  19. Effects of deviations from stoichiometry, oxygen excess and substitution of Cr for Fe on the chemical transport of hematite with TeCl 4 as a transporting agent

    NASA Astrophysics Data System (ADS)

    Peshev, P.; Toshev, A.; Krabbes, G.; Gerlach, U.; Opperman, H.

    1984-02-01

    Single crystals of pure hematite (α-Fe 2O 3) and hematite in which the iron is partially replaced by chromium (Fe 2- yCr yO 3) can be obtained by chemical transport using TeCl 4 as a transporting agent. A thermodynamic analysis has shown the transport to be substantially affected by some additional conditions such as slight deviations from stoichiometry and small amounts of excess oxygen and dopants. The transport of pure, practically stoichiometric hematite occurs at temperatures above 900°C in the direction from the hot to the cold zone. At pressures below 1 MPa and temperatures ranging from 750 to 900°C (which correspond to about 12 mg/ml TeCl 4), the transport proceeds in the opposite direction. However, in a similar temperature range, the transport reaction proceeds in the direction hot → cold again, on introducing small excess oxygen amounts into the ampoule and in cases when the hematite shows some oxygen deficiency. From a mixture of Fe 2O 3/Fe 3O 4, the hematite is transferred to the cold zone. Chromium-containing hematite is also transported to the cold zone. The composition of the mixed Fe 2- yCr yO 3 crystals obtained is different from that of the initial substance. All results of the thermodynamic analysis were confirmed by experiments.

  20. Basic Regulatory Principles of Escherichia coli's Electron Transport Chain for Varying Oxygen Conditions

    PubMed Central

    Henkel, Sebastian G.; Beek, Alexander Ter; Steinsiek, Sonja; Stagge, Stefan; Bettenbrock, Katja; de Mattos, M. Joost Teixeira; Sauter, Thomas; Sawodny, Oliver; Ederer, Michael

    2014-01-01

    For adaptation between anaerobic, micro-aerobic and aerobic conditions Escherichia coli's metabolism and in particular its electron transport chain (ETC) is highly regulated. Although it is known that the global transcriptional regulators FNR and ArcA are involved in oxygen response it is unclear how they interplay in the regulation of ETC enzymes under micro-aerobic chemostat conditions. Also, there are diverse results which and how quinones (oxidised/reduced, ubiquinone/other quinones) are controlling the ArcBA two-component system. In the following a mathematical model of the E. coli ETC linked to basic modules for substrate uptake, fermentation product excretion and biomass formation is introduced. The kinetic modelling focusses on regulatory principles of the ETC for varying oxygen conditions in glucose-limited continuous cultures. The model is based on the balance of electron donation (glucose) and acceptance (oxygen or other acceptors). Also, it is able to account for different chemostat conditions due to changed substrate concentrations and dilution rates. The parameter identification process is divided into an estimation and a validation step based on previously published and new experimental data. The model shows that experimentally observed, qualitatively different behaviour of the ubiquinone redox state and the ArcA activity profile in the micro-aerobic range for different experimental conditions can emerge from a single network structure. The network structure features a strong feed-forward effect from the FNR regulatory system to the ArcBA regulatory system via a common control of the dehydrogenases of the ETC. The model supports the hypothesis that ubiquinone but not ubiquinol plays a key role in determining the activity of ArcBA in a glucose-limited chemostat at micro-aerobic conditions. PMID:25268772

  1. KRW oxygen-blown gasification combined cycle: Carbon dioxide recovery, transport, and disposal

    SciTech Connect

    Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.R.

    1996-08-01

    This project emphasizes CO{sub 2}-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems. Complementary evaluations address CO{sub 2} transportation, CO{sub 2} use, and options for the long-term sequestration of unused CO{sub 2}. The intent is to provide the CO{sub 2} budget, or an equivalent CO{sub 2} budget, associated with each of the individual energy-cycle steps, in addition to process design capital and operating costs. The base case is a 458-MW (gross generation) IGCC system that uses an oxygen-blown Kellogg-Rust-Westinghouse agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal feed, and low-pressure glycol sulfur removal followed by Claus/SCOT treatment to produce a saleable product. Mining, feed preparation, and conversion result in a net electric power production for the entire energy cycle of 411 MW, with a CO{sub 2} release rate of 0.801 kg/k Whe. For comparison, in two cases, the gasifier output was taken through water-gas shift and then to low-pressure glycol H{sub 2}S recovery, followed by either low-pressure glycol or membrane CO{sub 2} recovery and then by a combustion turbine being fed a high-hydrogen-content fuel. Two additional cases employed chilled methanol for H{sub 2}S recovery and a fuel cell as the topping cycle with no shift stages. From the IGCC plant, a 500-km pipeline took the CO{sub 2} to geological sequestering. In a comparison of air-blown and oxygen-blown CO{sub 2}-release base cases, the cost of electricity for the air-blown IGCC was 56.86 mills/kWh, and the cost of oxygen-blown IGCC was 58.29 mills/kWh.

  2. Regulation of nitrite transport in red blood cells by hemoglobin oxygen fractional saturation.

    PubMed

    Vitturi, Dario A; Teng, Xinjun; Toledo, José C; Matalon, Sadis; Lancaster, Jack R; Patel, Rakesh P

    2009-05-01

    Allosteric regulation of nitrite reduction by deoxyhemoglobin has been proposed to mediate nitric oxide (NO) formation during hypoxia. Nitrite is predominantly an anion at physiological pH, raising questions about the mechanism by which it enters the red blood cell (RBC) and whether this is regulated and coupled to deoxyhemoglobin-mediated reduction. We tested the hypothesis that nitrite transport by RBCs is regulated by fractional saturation. Using human RBCs, nitrite consumption was faster at lower fractional saturations, consistent with faster reactions with deoxyheme. A membrane-based regulation was suggested by slower nitrite consumption with intact versus lysed RBCs. Interestingly, upon nitrite addition, intracellular nitrite concentrations attained a steady state that, despite increased rates of consumption, did not change with decreasing oxygen tensions, suggesting a deoxygenation-sensitive step that either increases nitrite import or decreases the rate of nitrite export. A role for anion exchanger (AE)-1 in the control of nitrite export was suggested by increased intracellular nitrite concentrations in RBCs treated with DIDS. Moreover, deoxygenation decreased steady-state levels of intracellular nitrite in AE-1-inhibited RBCs. Based on these data, we propose a model in which deoxyhemoglobin binding to AE-1 inhibits nitrite export under low oxygen tensions allowing for the coupling between deoxygenation and nitrite reduction to NO along the arterial-to-venous gradient. PMID:19286940

  3. ZERO EMISSION POWER PLANTS USING SOLID OXIDE FUEL CELLS AND OXYGEN TRANSPORT MEMBRANES

    SciTech Connect

    G. Maxwell Christie; Troy M. Raybold

    2003-06-10

    Over 16,700 hours of operational experience was gained for the Oxygen Transport Membrane (OTM) elements of the proposed SOFC/OTM zero-emission power generation concept. It was repeatedly demonstrated that OTMs with no additional oxidation catalysts were able to completely oxidize the remaining depleted fuel in a simulated SOFC anode exhaust at an O{sub 2} flux that met initial targets. In such cases, neither residual CO nor H{sub 2} were detected to the limits of the gas chromatograph (<10 ppm). Dried OTM afterburner exhaust streams contained up to 99.5% CO{sub 2}. Oxygen flux through modified OTMs was double or even triple that of the standard OTMs used for the majority of testing purposes. Both the standard and modified membranes in laboratory-scale and demonstration-sized formats exhibited stable performance over extended periods (2300 to 3500 hours or 3 to 5 months). Reactor contaminants, were determined to negatively impact OTM performance stability. A method of preventing OTM performance degradation was developed and proven to be effective. Information concerning OTM and seal reliability over extended periods and through various chemical and thermal shocks and cycles was also obtained. These findings were used to develop several conceptual designs for pilot (10 kWe) and commercial-scale (250 kWe) SOFC/OTM zero emission power generation systems.

  4. Effect on Oxygen Cost of Transport from 8-Weeks of Progressive Training with Barefoot Running.

    PubMed

    Tam, N; Tucker, R; Astephen Wilson, J L; Santos-Concejero, J

    2015-11-01

    Popular interest in barefoot running has emerged as a result of its alleged performance and injury prevention benefits. Oxygen cost of transport (COT) improvements from barefoot running, however, remains equivocal. The aim of this study was to determine the influence of an 8-week progressive barefoot training program on COT and associated spatiotemporal variables. 15 male runners participated in this study. Variables such as oxygen uptake, biomechanical and spatiotemporal characteristics of gait, including ground contact (GC) and swing time; stride length and frequency and ankle plantar-dorsiflexion were measured pre- and post-intervention. The COT did not differ between barefoot and shod running either pre- or post-training. Improved barefoot COT (p<0.05) but not shod was found between pre- and post-training. Biomechanical differences between barefoot and shod conditions persisted over the training period. A decrease in barefoot COT was associated with a decrease in GC time (p=0.003, r=0.688) and a small increase in stride frequency (p=0.030; r=0.569). Ground contact time and stride frequency, previously associated with COT, only partly contribute (32% - Stride frequency and 47% - GC time) to a decrease in COT after barefoot training. Thus other physiological and biomechanical variables must influence the improvement in COT after a barefoot training intervention. PMID:26332902

  5. Optical imaging measurements of oxygen transport fluctuations and gradients in tumor microvascular networks

    NASA Astrophysics Data System (ADS)

    Sorg, Brian S.; Hardee, Matthew E.; Moeller, Benjamin J.; Dewhirst, Mark W.

    2006-02-01

    It is well established that hypoxia can influence tumor biology and physiology, gene expression, metastatic potential, treatment efficacy, and patient survival. Most human solid tumors have been shown to have some hypoxic regions, thus there is a strong motivation to understand the various causes of hypoxia. One key to understanding tumor hypoxia involves the study of oxygen transport to tumors, and the connection between hypoxia, tumor microvasculature, and the tumor microenvironment. Recent research has suggested that the causes of tumor hypoxia are much more complex than indicated by the classical paradigms ("chronic" and "acute" hypoxia), and several potential factors have been identified. Two such factors are temporal fluctuations in tissue pO II and longitudinal gradients in oxygen transport. Research has shown the existence of low frequency (<2 cycles per minute) fluctuations in tumor pO II without cessation of blood flow that can lead to transient hypoxia. In addition, longitudinal gradients in tumor pO II along the arteriolar afferent direction have been documented in window chamber tumors. However, the causes of the pO II temporal fluctuations and longitudinal gradients are not exactly known, and the clinical significance of these observations is not well understood. In this preliminary study, we demonstrate the potential of optical imaging measurements of hemoglobin saturation to add new information in these areas. Slow temporal fluctuations of hemoglobin saturation (HbSat) and gradients in the average HbSat were observed in some 4T1 mouse mammary carcinoma microvessels. With additional research, the mechanisms behind these phenomena and insights into their clinical significance may be revealed.

  6. Oxygen adsorption and electronic transport properties of Fe-substituted YBaCo{sub 4}O{sub 7} compounds

    SciTech Connect

    Hao, Haoshan; He, Qinglin; Cheng, Yongguang; Zhao, Limin

    2014-05-01

    Graphical abstract: - Highlights: • The conduction mechanism of YBaCo{sub 4}O{sub 7} system was established. • The effect of Fe substitution on the electronic transport was discussed. • The effect of oxygen adsorption/desorption processes on the transport properties was investigated. - Abstract: YBaCo{sub 4−x}Fe{sub x}O{sub 7} (0.0 ≤ x ≤ 0.8) samples were prepared by the solid-state reaction method and the effect of Fe substitution and oxygen adsorption/desorption on the electronic transport properties was investigated from room temperature to 900 °C. Fe for Co substitution results in a slight decline in the oxygen storage capacity at lower temperature (200–400 °C) and an increase of the phase-decomposition temperature at higher temperature (700–900 °C). Both the hole concentration and mobility are reduced in the Fe-containing compositions. Electrical resistivity, Seebeck coefficient, and conduction activation energy increase with the increasing Fe content. A close correlativity between oxygen adsorption and electronic transport behavior was observed in YBaCo{sub 4−x}Fe{sub x}O{sub 7} system. Oxygen adsorption decreases the electrical resistivity and Seebeck coefficients because of the increase of hole concentration at lower temperature and the phase decomposition at higher temperature.

  7. Zero Emission Power Plants Using Solid Oxide Fuel Cells and Oxygen Transport Membranes

    SciTech Connect

    Shockling, Larry A.; Huang, Keqin; Gilboy, Thomas E.; Christie, G. Maxwell; Raybold, Troy M.

    2001-11-06

    Siemens Westinghouse Power Corp. (SWPC) is engaged in the development of Solid Oxide Fuel Cell stationary power systems. SWPC has combined DOE Developmental funds with commercial customer funding to establish a record of successful SOFC field demonstration power systems of increasing size. SWPC will soon deploy the first unit of a newly developed 250 kWe Combined Heat Power System. It will generate electrical power at greater than 45% electrical efficiency. The SWPC SOFC power systems are equipped to operate on lower number hydrocarbon fuels such as pipeline natural gas, which is desulfurized within the SOFC power system. Because the system operates with a relatively high electrical efficiency, the CO2 emissions, {approx}1.0 lb CO2/ kW-hr, are low. Within the SOFC module the desulfurized fuel is utilized electrochemically and oxidized below the temperature for NOx generation. Therefore the NOx and SOx emissions for the SOFC power generation system are near negligible. The byproducts of the power generation from hydrocarbon fuels that are released into the environment are CO2 and water vapor. This forward looking DOE sponsored Vision 21 program is supporting the development of methods to capture and sequester the CO2, resulting in a Zero Emission power generation system. To accomplish this, SWPC is developing a SOFC module design, to be demonstrated in operating hardware, that will maintain separation of the fuel cell anode gas, consisting of H2, CO, H2O and CO2, from the vitiated air. That anode gas, the depleted fuel stream, containing less than 18% (H2 + CO), will be directed to an Oxygen Transport Membrane (OTM) Afterburner that is being developed by Praxair, Inc.. The OTM is supplied air and the depleted fuel. The OTM will selectively transport oxygen across the membrane to oxidize the remaining H2 and CO. The water vapor is then condensed from the totally 1.5.DOC oxidized fuel stream exiting the afterburner, leaving only the CO2 in gaseous form. That CO2 can

  8. Unprecedented Perovskite Oxyfluoride Membranes with High-Efficiency Oxygen Ion Transport Paths for Low-Temperature Oxygen Permeation.

    PubMed

    Zhu, Jiawei; Liu, Gongping; Liu, Zhengkun; Chu, Zhenyu; Jin, Wanqin; Xu, Nanping

    2016-05-01

    Unprecedented perovskite oxyfluoride membranes, a new generation of mixed ionic-electronic conducting (MIEC) membranes, feature extraordinary performance for low-temperature oxygen permeation, which transcend the performance of state-of-the-art MIEC membranes and fulfil commercial requirements. These results provide important progress for MIEC membranes and will potentially open the door to exploring high-performance MIEC compounds. PMID:26970399

  9. Simulating unsteady transport of nitrogen, biochemical oxygen demand, and dissolved oxygen in the Chattahoochee River downstream from Atlanta, Georgia

    USGS Publications Warehouse

    Jobson, Harvey E.

    1985-01-01

    As part of an intensive water-quality assessment of the Chattahoochee River, repetitive water-quality measurements were made at 12 sites along a 69-kilometer reach of the river downstream of Atlanta, Georgia. Concentrations of seven constituents (temperature, dissolved oxygen, ultimate carbonaceous biochemical oxygen demand (BOD), organic nitrogen, ammonia, nitrite, and nitrate) were obtained during two periods of 36 hours, one starting on August 30, 1976, and the other starting on May 31, 1977. The study reach contains one large and several small sewage outfalls and receives the cooling water from two large powerplants. An unsteady water-quality model of the Lagrangian type was calibrated using the 1977 data and verified using the 1976 data. The model provided a good means of interpreting these data even though both the flow and the pollution loading rates were highly unsteady. A kinetic model of the cascade type accurately described the physical and biochemical processes occurring in the river. All rate coefficients, except reaeration coefficients and those describing the resuspension of BOD, were fitted to the 1977 data and verified using the 1976 data. The study showed that, at steady low flow, about 38 percent of the BOD settled without exerting an oxygen demand. At high flow, this settled BOD was resuspended and exerted an immediate oxygen demand. About 70 percent of the ammonia extracted from the water column was converted to nitrite, but the fate of the remaining 30 percent is unknown. Photosynthetic production was not an important factor in the oxygen balance during either run.

  10. Predicted consequences of diabetes and SGLT inhibition on transport and oxygen consumption along a rat nephron.

    PubMed

    Layton, Anita T; Vallon, Volker; Edwards, Aurélie

    2016-06-01

    Diabetes increases the reabsorption of Na(+) (TNa) and glucose via the sodium-glucose cotransporter SGLT2 in the early proximal tubule (S1-S2 segments) of the renal cortex. SGLT2 inhibitors enhance glucose excretion and lower hyperglycemia in diabetes. We aimed to investigate how diabetes and SGLT2 inhibition affect TNa and sodium transport-dependent oxygen consumption [Formula: see text] along the whole nephron. To do so, we developed a mathematical model of water and solute transport from the Bowman space to the papillary tip of a superficial nephron of the rat kidney. Model simulations indicate that, in the nondiabetic kidney, acute and chronic SGLT2 inhibition enhances active TNa in all nephron segments, thereby raising [Formula: see text] by 5-12% in the cortex and medulla. Diabetes increases overall TNa and [Formula: see text] by ∼50 and 100%, mainly because it enhances glomerular filtration rate (GFR) and transport load. In diabetes, acute and chronic SGLT2 inhibition lowers [Formula: see text] in the cortex by ∼30%, due to GFR reduction that lowers proximal tubule active TNa, but raises [Formula: see text] in the medulla by ∼7%. In the medulla specifically, chronic SGLT2 inhibition is predicted to increase [Formula: see text] by 26% in late proximal tubules (S3 segments), by 2% in medullary thick ascending limbs (mTAL), and by 9 and 21% in outer and inner medullary collecting ducts (OMCD and IMCD), respectively. Additional blockade of SGLT1 in S3 segments enhances glucose excretion, reduces [Formula: see text] by 33% in S3 segments, and raises [Formula: see text] by <1% in mTAL, OMCD, and IMCD. In summary, the model predicts that SGLT2 blockade in diabetes lowers cortical [Formula: see text] and raises medullary [Formula: see text], particularly in S3 segments. PMID:26764207

  11. Haematological toxicity of drugs used in psychiatry.

    PubMed

    Flanagan, Robert J; Dunk, Louisa

    2008-01-01

    Almost all classes of psychotropic agents have been reported to cause blood dyscrasias. Mechanisms include direct toxic effects upon the bone marrow, the formation of antibodies against haematopoietic precursors or involve peripheral destruction of cells. Agranulocytosis is probably the most important drug-related blood dyscrasia. The mortality from drug-induced agranulocytosis is 5-10% in Western countries. The manifestations of agranulocytosis are secondary to infection. Aggressive treatment with intravenous broad-spectrum antimicrobials and bone marrow stimulants may be required. Of drugs encountered in psychiatry, antipsychotics including clozapine (risk of agranulocytosis approximately 0.8%, predominantly in the first year of treatment) and phenothiazines (chlorpromazine agranulocytosis risk approximately 0.13%), and antiepileptics (notably carbamazepine, neutropenia risk approximately 0.5%) are the most common causes of drug-related neutropenia/agranulocytosis. Drugs known to cause neutropenia should not be used concomitantly with other drugs known to cause this problem. High temperature and other indicators of possible infection should be looked for routinely during treatment. Clozapine is well known as a drug that can cause blood dyscrasias, but olanzapine and other atypicals may also cause similar problems. In addition to genetic factors, there are likely to be dose-related and immunological components to these phenomena. Important lessons have been learnt from the haematological monitoring that is necessary with clozapine and the monitoring has been very successful in preventing deaths related to clozapine-induced agranulocytosis. Continuing research into the mechanisms of drug-induced neutropenia and agranulocytosis may serve to further enhance the safe use not only of clozapine, but also of other agents. PMID:18098216

  12. Zygomycosis in Immunocompromised non-Haematological Patients

    PubMed Central

    Petrikkos, George; Drogari-Apiranthitou, Miranda

    2011-01-01

    Zygomycoses caused by fungi of the mucorales order (mucormycoses) are emerging fungal diseases with a high fatality rate. The most important risk factors include neutropenia or functional neutropenia, diabetic ketoacidosis, iron overload, major trauma, prolonged use of corticosteroids, illicit intravenous drug (ID) use, neonatal prematurity, malnourishment, and maybe a previous exposure to antifungal agents with no activity against zygomycetes, such as voriconazole and echinocandins. A high index of suspicion is crucial for the diagnosis, as prompt and appropriate management can considerably reduce morbidity and mortality. Suspicion index can be increased through recognition of the differential patterns of clinical presentation. In the non- haematological immunocompromised patients, mucormycosis can manifest in various clinical forms, depending on the underlying condition: mostly as rhino-orbital or rhino-cerebral in diabetes patients, pulmonary infection in patients with malignancy or solid organ transplantation, disseminated infection in iron overloaded or deferoxamine treated patients, cerebral - with no sinus involvement - in ID users, gastrointestinal in premature infants or malnourishment, and cutaneous after direct inoculation in immunocompetent individuals with trauma or burns. Treating a patient’s underlying medical condition and reducing immunosuppression are essential to therapy. Rapid correction of metabolic abnormalities is mandatory in cases such as uncontrolled diabetes, and corticosteroids or other immunosuppressive drugs should be discontinued where feasible. AmphotericinB or its newer and less toxic lipid formulations are the drugs of choice regarding antifungal chemotherapy, while extensive surgical debridement is essential to reduce infected and necrotic tissue. A high number of cases could be prevented through measures including diabetes control programmes and proper pre- and post-surgical hygiene. PMID:21625316

  13. Stem hypertrophic lenticels and secondary aerenchyma enable oxygen transport to roots of soybean in flooded soil

    PubMed Central

    Shimamura, Satoshi; Yamamoto, Ryo; Nakamura, Takuji; Shimada, Shinji; Komatsu, Setsuko

    2010-01-01

    Background and Aims Aerenchyma provides a low-resistance O2 transport pathway that enhances plant survival during soil flooding. When in flooded soil, soybean produces aerenchyma and hypertrophic stem lenticels. The aims of this study were to investigate O2 dynamics in stem aerenchyma and evaluate O2 supply via stem lenticels to the roots of soybean during soil flooding. Methods Oxygen dynamics in aerenchymatous stems were investigated using Clark-type O2 microelectrodes, and O2 transport to roots was evaluated using stable-isotope 18O2 as a tracer, for plants with shoots in air and roots in flooded sand or soil. Short-term experiments also assessed venting of CO2 via the stem lenticels. Key Results The radial distribution of the O2 partial pressure (pO2) was stable at 17 kPa in the stem aerenchyma 15 mm below the water level, but rapidly declined to 8 kPa at 200–300 µm inside the stele. Complete submergence of the hypertrophic lenticels at the stem base, with the remainder of the shoot still in air, resulted in gradual declines in pO2 in stem aerenchyma from 17·5 to 7·6 kPa at 13 mm below the water level, and from 14·7 to 6·1 kPa at 51 mm below the water level. Subsequently, re-exposure of the lenticels to air caused pO2 to increase again to 14–17 kPa at both positions within 10 min. After introducing 18O2 gas via the stem lenticels, significant 18O2 enrichment in water extracted from roots after 3 h was confirmed, suggesting that transported O2 sustained root respiration. In contrast, slight 18O2 enrichment was detected 3 h after treatment of stems that lacked aerenchyma and lenticels. Moreover, aerenchyma accelerated venting of CO2 from submerged tissues to the atmosphere. Conclusions Hypertrophic lenticels on the stem of soybean, just above the water surface, are entry points for O2, and these connect to aerenchyma and enable O2 transport into roots in flooded soil. Stems that develop aerenchyma thus serve as a ‘snorkel’ that enables O2 movement

  14. The Effects of Amiloride and Age on Oxygen Consumption Coupled to Electrogenic Sodium Transport in the Human Sigmoid Colon

    PubMed Central

    Carra, Graciela E.; Matus, Daniel; Ibáñez, Jorge E.; Saraví, Fernando D.

    2015-01-01

    Background/Aim: Aerobic metabolism is necessary for ion transport in many transporting epithelia, including the human colonic epithelium. We assessed the effects of the epithelial sodium channel blocker, amiloride, on oxygen consumption and short-circuit current of the human sigmoid epithelium to determine whether these effects were influenced by the age of the subject. Materials and Methods: Segments of the sigmoid colon were obtained from the safety margin of resections performed in patients of 62–77 years of age. Isolated mucosa preparations were obtained and mounted in airtight Ussing chambers, fit for simultaneous measurement of short-circuit current and oxygen concentration, before and after blocking epithelial sodium channels with amiloride (0.1 mmol/L). Regression analyses were performed to assess the associations between short-circuit current, oxygen consumption, and age of the subject as well as to define the relationship between the decreases in short-circuit current and oxygen consumption after blockade. Results: Epithelial sodium channel blockade caused an 80% reduction in short-circuit current and a 26% reduction in oxygen consumption. Regression analysis indicated that both changes were significantly related (r = 0.884; P = 0.0007). Oxygen consumption decreased by 1 μmol/h/cm2 for each 25 μA/cm2 decrease in short-circuit current. Neither short-circuit current nor oxygen consumption had any significant relationship with the age of the subjects. Conclusion: The decrease in epithelial oxygen consumption caused by amiloride is proportional to the decrease in short-circuit current and independent of the age of the subject. PMID:26458855

  15. Muscle oxygen transport and utilization in heart failure: implications for exercise (in)tolerance

    PubMed Central

    Hirai, Daniel M.; Copp, Steven W.; Musch, Timothy I.

    2012-01-01

    The defining characteristic of chronic heart failure (CHF) is an exercise intolerance that is inextricably linked to structural and functional aberrations in the O2 transport pathway. CHF reduces muscle O2 supply while simultaneously increasing O2 demands. CHF severity varies from moderate to severe and is assessed commonly in terms of the maximum O2 uptake, which relates closely to patient morbidity and mortality in CHF and forms the basis for Weber and colleagues' (167) classifications of heart failure, speed of the O2 uptake kinetics following exercise onset and during recovery, and the capacity to perform submaximal exercise. As the heart fails, cardiovascular regulation shifts from controlling cardiac output as a means for supplying the oxidative energetic needs of exercising skeletal muscle and other organs to preventing catastrophic swings in blood pressure. This shift is mediated by a complex array of events that include altered reflex and humoral control of the circulation, required to prevent the skeletal muscle “sleeping giant” from outstripping the pathologically limited cardiac output and secondarily impacts lung (and respiratory muscle), vascular, and locomotory muscle function. Recently, interest has also focused on the dysregulation of inflammatory mediators including tumor necrosis factor-α and interleukin-1β as well as reactive oxygen species as mediators of systemic and muscle dysfunction. This brief review focuses on skeletal muscle to address the mechanistic bases for the reduced maximum O2 uptake, slowed O2 uptake kinetics, and exercise intolerance in CHF. Experimental evidence in humans and animal models of CHF unveils the microvascular cause(s) and consequences of the O2 supply (decreased)/O2 demand (increased) imbalance emblematic of CHF. Therapeutic strategies to improve muscle microvascular and oxidative function (e.g., exercise training and anti-inflammatory, antioxidant strategies, in particular) and hence patient exercise

  16. On the effect of serum on the transport of reactive oxygen species across phospholipid membranes.

    PubMed

    Szili, Endre J; Hong, Sung-Ha; Short, Robert D

    2015-01-01

    The transport of plasma generated reactive oxygen species (ROS) across a simple phospholipid membrane mimic of a (real) cell was investigated. Experiments were performed in cell culture media (Dulbecco's modified Eagle's medium, DMEM), with and without 10% serum. A (broad spectrum) ROS reporter dye, 2,7-dichlorodihydrofluorescein (DCFH), was used to detect the generation of ROS by a helium (He) plasma jet in DMEM using free DCFH and with DCFH encapsulated inside phospholipid membrane vesicles dispersed in DMEM. The authors focus on the concentration and on the relative rates (arbitrary units) for oxidation of DCFH [or the appearance of the oxidized product 2,7-dichlorofluorescein (DCF)] both in solution and within vesicles. In the first 1 h following plasma exposure, the concentration of free DCF in DMEM was ~15× greater in the presence of serum (cf. to the serum-free DMEM control). The DCF in vesicles was ~2× greater in DMEM containing serum compared to the serum-free DMEM control. These data show that serum enhances plasma ROS generation in DMEM. As expected, the role of the phospholipid membrane was to reduce the rate of oxidation of the encapsulated DCFH (with and without serum). And the efficiency of ROS transport into vesicles was lower in DMEM containing serum (at 4% efficiency) when compared to serum-free DMEM (at 32% efficiency). After 1 h, the rate of DCFH oxidation was found to have significantly reduced. Based upon a synthesis of these data with results from the open literature, the authors speculate on how the components of biological fluid and cellular membranes might affect the kinetics of consumption of plasma generated ROS. PMID:25910641

  17. The Effect of Sustained Compression on Oxygen Metabolic Transport in the Intervertebral Disc Decreases with Degenerative Changes

    PubMed Central

    Malandrino, Andrea; Noailly, Jérôme; Lacroix, Damien

    2011-01-01

    Intervertebral disc metabolic transport is essential to the functional spine and provides the cells with the nutrients necessary to tissue maintenance. Disc degenerative changes alter the tissue mechanics, but interactions between mechanical loading and disc transport are still an open issue. A poromechanical finite element model of the human disc was coupled with oxygen and lactate transport models. Deformations and fluid flow were linked to transport predictions by including strain-dependent diffusion and advection. The two solute transport models were also coupled to account for cell metabolism. With this approach, the relevance of metabolic and mechano-transport couplings were assessed in the healthy disc under loading-recovery daily compression. Disc height, cell density and material degenerative changes were parametrically simulated to study their influence on the calculated solute concentrations. The effects of load frequency and amplitude were also studied in the healthy disc by considering short periods of cyclic compression. Results indicate that external loads influence the oxygen and lactate regional distributions within the disc when large volume changes modify diffusion distances and diffusivities, especially when healthy disc properties are simulated. Advection was negligible under both sustained and cyclic compression. Simulating degeneration, mechanical changes inhibited the mechanical effect on transport while disc height, fluid content, nucleus pressure and overall cell density reductions affected significantly transport predictions. For the healthy disc, nutrient concentration patterns depended mostly on the time of sustained compression and recovery. The relevant effect of cell density on the metabolic transport indicates the disturbance of cell number as a possible onset for disc degeneration via alteration of the metabolic balance. Results also suggest that healthy disc properties have a positive effect of loading on metabolic transport. Such

  18. A potentiostatic study of oxygen transport through poly(2-ethoxyethyl methacrylate-co-2,3-dihydroxypropylmethacrylate) hydrogel membranes.

    PubMed

    Compañ, Vicente; Tiemblo, Pilar; García, F; García, J M; Guzmán, Julio; Riande, Evaristo

    2005-06-01

    The oxygen permeability and diffusion coefficients of hydrogel membranes prepared with copolymers of 2-ethoxyethyl methacrylate (EEMA)/2,3-dihydroxypropylmethacrylate (MAG) with mole fraction of the second monomer in the range between 0 and 0.75 are described. Values of the permeability and diffusion coefficients of oxygen are determined by using electrochemical procedures involving the measurement of the steady-state current in membranes prepared by radical polymerization of the monomers. The results obtained for the transport properties were analyzed taking into account the fractional free volumes, the cohesive energy densities and the glass transition temperatures of the hydrogels. PMID:15626426

  19. Oxygen transport through soft contact lens and cornea: Lens characterization and metabolic modeling

    NASA Astrophysics Data System (ADS)

    Chhabra, Mahendra

    The human cornea requires oxygen to sustain metabolic processes critical for its normal functioning. Any restriction to corneal oxygen supply from the external environment (e.g., by wearing a low oxygen-permeability contact lens) can lead to hypoxia, which may cause corneal edema (swelling), limbal hyperemia, neovascularization, and corneal acidosis. The need for adequate oxygen to the cornea is a major driving force for research and development of hypertransmissible soft contact lenses (SCLs). Currently, there is no standard technique for measuring oxygen permeability (Dk) of hypertransmissible silicone-hydrogel SCLs. In this work, an electrochemistry-based polarographic apparatus was designed, built, and operated to measure oxygen permeability in hypertransmissible SCLs. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, this apparatus requires only a single lens thickness. The single-lens permeameter provides a reliable, efficient, and economic tool for measuring oxygen permeabilities of commercial hypertransmissible SCLs. The single-lens permeameter measures not only the product Dk, but, following modification, it measures separately diffusivity, D, and solubility, k, of oxygen in hypertransmissible SCLs. These properties are critical for designing better lens materials that ensure sufficient oxygen supply to the cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment, Thus, estimation of the in-vivo corneal oxygen consumption rate is essential for gauging adequate oxygen supply to the cornea. Therefore, we have developed an unsteady-state reactive-diffusion model for the cornea-contact-lens system to determine in-vivo human corneal oxygen-consumption rate. Finally, a metabolic model was developed to determine the relation between contact-lens oxygen transmissibility (Dk/L) and corneal oxygen deficiency. A

  20. The role of facilitated diffusion in oxygen transport by cell-free hemoglobins: implications for the design of hemoglobin-based oxygen carriers.

    PubMed

    McCarthy, M R; Vandegriff, K D; Winslow, R M

    2001-08-30

    We compared rates of oxygen transport in an in vitro capillary system using red blood cells (RBCs) and cell-free hemoglobins. The axial PO(2) drop down the capillary was calculated using finite-element analysis. RBCs, unmodified hemoglobin (HbA(0)), cross-linked hemoglobin (alpha alpha-Hb) and hemoglobin conjugated to polyethylene-glycol (PEG-Hb) were evaluated. According to their fractional saturation curves, PEG-Hb showed the least desaturation down the capillary, which most closely matched the RBCs; HbA(0) and alpha alpha-Hb showed much greater desaturation. A lumped diffusion parameter, K*, was calculated based on the Fick diffusion equation with a term for facilitated diffusion. The overall rates of oxygen transfer are consistent with hemoglobin diffusion rates according to the Stokes-Einstein Law and with previously measured blood pressure responses in rats. This study provides a conceptual framework for the design of a 'blood substitute' based on mimicking O(2) transport by RBCs to prevent autoregulatory changes in blood flow and pressure. PMID:11527583

  1. Scaling laws for oxygen transport across the space-filling system of respiratory membranes in the human lung

    NASA Astrophysics Data System (ADS)

    Hou, Chen

    Space-filling fractal surfaces play a fundamental role in how organisms function at various levels and in how structure determines function at different levels. In this thesis, we develop a quantitative theory of oxygen transport to and across the surface of the highly branched, space-filling system of alveoli, the fundamental gas exchange unit (acinar airways), in the human lung. Oxygen transport in the acinar airways is by diffusion, and we treat the two steps---diffusion through the branched airways, and transfer across the alveolar membranes---as a stationary diffusion-reaction problem, taking into account that there may be steep concentration gradients between the entrance and remote alveoli (screening). We develop a renormalization treatment of this screening effect and derive an analytic formula for the oxygen current across the cumulative alveolar membrane surface, modeled as a fractal, space-filling surface. The formula predicts the current from a minimum of morphological data of the acinus and appropriate values of the transport parameters, through a number of power laws (scaling laws). We find that the lung at rest operates near the borderline between partial screening and no screening; that it switches to no screening under exercise; and that the computed currents agree with measured values within experimental uncertainties. From an analysis of the computed current as a function of membrane permeability, we find that the space-filling structure of the gas exchanger is simultaneously optimal with respect to five criteria. The exchanger (i) generates a maximum oxygen current at minimum permeability; (ii) 'wastes' a minimum of surface area; (iii) maintains a minimum residence time of oxygen in the acinar airways; (iv) has a maximum fault tolerance to loss of permeability; and (v) generates a maximum current increase when switching from rest to exercise.

  2. Curriculum Design of a Flipped Classroom to Enhance Haematology Learning

    ERIC Educational Resources Information Center

    Porcaro, Pauline A.; Jackson, Denise E.; McLaughlin, Patricia M.; O'Malley, Cindy J.

    2016-01-01

    A common trend in higher education is the "flipped" classroom, which facilitates active learning during class. The flipped approach to teaching was instituted in a haematology "major" class and the students' attitudes and preferences for the teaching materials were surveyed. The curriculum design was explicit and involved four…

  3. The Potential Role of Aurora Kinase Inhibitors in Haematological Malignancies

    PubMed Central

    Farag, Sherif S.

    2011-01-01

    Summary Aurora kinases play an important role in the control of the cell cycle and have been implicated in tumourigenesis in a number of cancers. Among the haematological malignancies, overexpression of Aurora kinases has been reported in acute myeloid leukaemia, chronic myeloid leukaemia, acute lymphoblastic leukaemia, multiple myeloma, aggressive non-Hodgkin lymphoma and Hodgkin lymphoma. A large number of Aurora kinase inhibitors are currently in different stages of clinical development. In addition to varying in their selectivity for the different Aurora kinases, some also have activity directed at other cellular kinases involved in important molecular pathways in cancer cells. This review summarizes the biology of Aurora kinases and discusses why they may be good therapeutic targets in different haematological cancers. We describe preclinical data that has served as the rationale for investigating Aurora kinase inhibitors in different haematological malignancies, and summarize published results from early phase clinical trials. While the anti-tumour effects of Aurora kinase inhibitors appear promising, we highlight important issues for future clinical research and suggest that the optimal use of these inhibitors is likely to be in combination with cytotoxic agents already in use for the treatment of various haematological cancers. PMID:21980926

  4. A method for estimating the volume of oxygen required by Channel Catfish Ictalurus Punctatus and Blue Catfish Ictalurus Furcatus, during transport

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most transporters of live fish provide supplemental aeration by diffusing pure oxygen in hauling tanks. Transporters typically use a thumb rule approach, in which knowledge of a particular species, ambient air temperature, haul tank water temperature, loading density, and transport time are consider...

  5. 76 FR 12556 - Airworthiness Directives; Various Transport Category Airplanes Equipped With Chemical Oxygen...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034... Category Airplanes Equipped With Chemical Oxygen Generators Installed in a Lavatory AGENCY: Federal... affected airplanes identified above. This AD requires modifying the chemical oxygen generators in...

  6. Sufficient oxygen can be transported to resting skeletal muscle via arterialization of the vein: theoretical considerations in a rat model.

    PubMed

    Koyama, Tomiyasu; Koyama, Tomiyasu; Sasajima, Tadahiro

    2011-01-01

    The blood supply to the lower limbs is often interrupted in patients suffering from arteriosclerosis obliterans (AO). In this condition, it is necessary to establish an oxygen supply via an alternative route. In the present theoretical study on rats, the possibility that adequate oxygen could be supplied through the venous system has been considered using simple calculations. The study was undertaken in the light of a report of a successful surgical approach in which the capillary bed is bypassed [1].The total lengths of the collecting venules and of the arcade venules per mm3 are reported to be 2.32 and 2.11 mm, respectively [2]. If these vessels were stretched out and connected to form a single, narrow venular tube, the total density would be 4.43 mm/mm(3). From the reciprocal of this value, the tissue cylinder surrounding the venule would have a radius of 268 µm. Taking an oxygen consumption rate for resting skeletal muscle of 0.16 ml/100g/min, and pO2 value of 40 mmHg, the one-dimensional diffusion equation gives a maximal diffusion distance of 328 µm. This is larger than the radius of the tissue cylinder surrounding the venular tube. A calculation for Krogh's tissue cylinder gives an oxygen partial pressure gradient of 54 mmHg between the inflow and the outflow terminals. These calculations suggest the oxygen content of the venous blood is adequate to supply sufficient oxygen to resting skeletal muscle. This is consistent with the successful outcome in patients with direct A-V anastomoses and implies that the capillary network is not essential for oxygen transport to resting skeletal muscle. PMID:21445806

  7. Haematological parameters in Umbrina cirrosa (Teleostei, Sciaenidae): a comparison between diploid and triploid specimens.

    PubMed

    Ballarin, Loriano; Dall'Oro, Manuela; Bertotto, Daniela; Libertini, Angelo; Francescon, Antonia; Barbaro, Alvise

    2004-05-01

    Haematological features were compared between diploid and triploid specimens of the ray-finned fish Umbrina cirrosa. No significant differences between diploids and triploids were reported in haematocrit and total haemoglobin concentration, but erythrocytes and thrombocytes were significantly greater in size in triploids. Glycaemia was significantly lower in diploids, whereas triploid erythrocytes were more resistant to osmotic stress. In triploids, a greater fraction of leukocytes was positive for alkaline phosphatase activity, when stimulated with Bacillus clausii spores, otherwise no significant increase of oxygen consumption was observed in triploid leukocytes after stimulation, based on assays for superoxide anions. Triploids were characterized by a lower concentration of circulating blood cells with a lower surface/volume ratio when compared with diploids. These features may lead to a general disadvantage of triploids in withstanding stress conditions: a situation that needs to be taken into account in aquaculture practice. PMID:15165570

  8. Structural features and enhanced high-temperature oxygen ion transport in SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}

    SciTech Connect

    Markov, Alexey A.; Shalaeva, Elizaveta V.; Tyutyunnik, Alexander P.; Kuchin, Vasily V.; Patrakeev, Mikhail V.; Leonidov, Ilya A.; Kozhevnikov, Victor L.

    2013-01-15

    Structural features, oxygen non-stoichiometry and transport properties are studied in the oxide series SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}, where x=0.2, 0.3 and 0.4. X-ray diffraction and electron microscopy data evidence formation of the inhomogeneous materials at x=0.3 and 0.4, which include phase constituents with a cubic perovskite and a double perovskite structure types. The composition, the amount and the typical grain size of the phase inhomogeneities are shown to depend both on doping and oxygen content. The increased oxygen-ion conductivity is observed in oxygen depleted materials, which is explained by the increase in the amount of cubic perovskite-like phase and development of interfacial pathways favorable for enhanced oxygen ion transport. - Graphical abstract: The structural studies, oxygen content and conductivity measurements suggest that oxygen depletion from the double perovskite phase constituent of SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}} for x>0.2 is accompanied by formation of pathways for fast ion transport. Black-Small-Square Highlights: Black-Right-Pointing-Pointer The double perovskite type regions are shown to exist in SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}. Black-Right-Pointing-Pointer The oxygen depletion is accompanied with phase separation. Black-Right-Pointing-Pointer The phase separation favors formation of pathways for enhanced oxygen ion transport.

  9. Blood flow mechanics and oxygen transport and delivery in the retinal microcirculation: multiscale mathematical modeling and numerical simulation.

    PubMed

    Causin, Paola; Guidoboni, Giovanna; Malgaroli, Francesca; Sacco, Riccardo; Harris, Alon

    2016-06-01

    The scientific community continues to accrue evidence that blood flow alterations and ischemic conditions in the retina play an important role in the pathogenesis of ocular diseases. Many factors influence retinal hemodynamics and tissue oxygenation, including blood pressure, blood rheology, oxygen arterial permeability and tissue metabolic demand. Since the influence of these factors on the retinal circulation is difficult to isolate in vivo, we propose here a novel mathematical and computational model describing the coupling between blood flow mechanics and oxygen ([Formula: see text]) transport in the retina. Albeit in a simplified manner, the model accounts for the three-dimensional anatomical structure of the retina, consisting in a layered tissue nourished by an arteriolar/venular network laying on the surface proximal to the vitreous. Capillary plexi, originating from terminal arterioles and converging into smaller venules, are embedded in two distinct tissue layers. Arteriolar and venular networks are represented by fractal trees, whereas capillary plexi are represented using a simplified lumped description. In the model, [Formula: see text] is transported along the vasculature and delivered to the tissue at a rate that depends on the metabolic demand of the various tissue layers. First, the model is validated against available experimental results to identify baseline conditions. Then, a sensitivity analysis is performed to quantify the influence of blood pressure, blood rheology, oxygen arterial permeability and tissue oxygen demand on the [Formula: see text] distribution within the blood vessels and in the tissue. This analysis shows that: (1) systemic arterial blood pressure has a strong influence on the [Formula: see text] profiles in both blood and tissue; (2) plasma viscosity and metabolic consumption rates have a strong influence on the [Formula: see text] tension at the level of the retinal ganglion cells; and (3) arterial [Formula: see text

  10. Influence of temperature on oxygen permeation through ion transport membrane to feed a biomass gasifier

    NASA Astrophysics Data System (ADS)

    Antonini, T.; Foscolo, P. U.; Gallucci, K.; Stendardo, S.

    2015-11-01

    Oxygen-permeable perovskite membranes with mixed ionic-electronic conducting properties can play an important role in the high temperature separation of oxygen from air. A detailed design of a membrane test module is presented, useful to test mechanical resistance and structural stability of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) capillary membrane in the reactor environment. Preliminary experimental results of membrane permeation tests highlight the positive effect of temperature on perovskite materials. This behaviour is also confirmed by a computational model of char combustion with oxygen permeated through the membrane module, when it is placed inside a gasifier reactor to provide the necessary input of heat to the gasification endothermic process. The results show that the temperature affects the oxygen permeation of the BSCF membrane remarkably.

  11. The Role of Oxygen Partial Pressure in Controlling the Phase Composition of La1- x Sr x Co y Fe1- y O3- δ Oxygen Transport Membranes Manufactured by Means of Plasma Spray-Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Marcano, D.; Mauer, G.; Sohn, Y. J.; Vaßen, R.; Garcia-Fayos, J.; Serra, J. M.

    2016-04-01

    La0.58Sr0.4Co0.2Fe0.8O3 - δ (LSCF) deposited on a metallic porous support by plasma spray-physical vapor deposition is a promising candidate for oxygen-permeation membranes. Ionic transport properties are regarded to depend on the fraction of perovskite phase present in the membrane. However, during processing, the LSCF powder decomposes into perovskite and secondary phases. In order to improve the ionic transport properties of the membranes, spraying was carried out at different oxygen partial pressures p(O2). It was found that coatings deposited at lower and higher oxygen partial pressures consist of 70% cubic/26% rhombohedral and 61% cubic/35% rhombohedral perovskite phases, respectively. During annealing, the formation of non-perovskite phases is driven by oxygen non-stoichiometry. The amount of oxygen added during spraying can be used to increase the perovskite phase fraction and suppress the formation of non-perovskite phases.

  12. In vivo oxygen transport in the normal rabbit femoral arterial wall.

    PubMed Central

    Crawford, D W; Back, L H; Cole, M A

    1980-01-01

    In vivo measurements of tissue oxygen tension were made at 10-micrometer intervals through functioning in situ rabbit femoral arterial walls, using inhalation anesthesia and recessed microcathodes with approximately 4-micrometer external diameters. External environment was controlled with a superfusion well at 30 torr PO2, 35 torr PCO2. Blood pressure, gas tension levels, and blood pH were held within the normal range. Radial PO2 measurements closely fit a mathematical model for unidimensional diffusion into a thick-walled artery with uniform oxygen consumption, and the distances traversed fit measured dimensions of quick-frozen in vivo sections. Using standard values of diffusion and solubility coefficients, mean calculated medial oxygen consumption was 99 nl0/ml-s. Mural oxygen consumption appeared to be related linearly to mean tangential wall stress. Differences in experimental design and technique were compared with previous in vivo and in vitro measurements of wall oxygenation, and largely account for the varying results obtained. Control of environment external to the artery, and maintenance of normally flowing blood in the lumen in vivo appeared critical to an understanding of mural oxygenation in life. If the conditions of this experiment prevailed in arteries with thicker avascular layers, PO2 could have been 20 torr at approximately 156 micrometer and 10 torr at 168 micrometer from blood (average values). Images PMID:7410554

  13. The effect of in-plane arterial curvature on blood flow and oxygen transport in arterio-venous fistulae

    PubMed Central

    Iori, F.; Grechy, L.; Gedroyc, W.; Duncan, N.; Caro, C. G.; Vincent, P. E.

    2015-01-01

    Arterio-Venous Fistulae (AVF) are the preferred method of vascular access for patients with end stage renal disease who need hemodialysis. In this study, simulations of blood flow and oxygen transport were undertaken in various idealized AVF configurations. The objective of the study was to understand how arterial curvature affects blood flow and oxygen transport patterns within AVF, with a focus on how curvature alters metrics known to correlate with vascular pathology such as Intimal Hyperplasia (IH). If one subscribes to the hypothesis that unsteady flow causes IH within AVF, then the results suggest that in order to avoid IH, AVF should be formed via a vein graft onto the outer-curvature of a curved artery. However, if one subscribes to the hypothesis that low wall shear stress and/or low lumen-to-wall oxygen flux (leading to wall hypoxia) cause IH within AVF, then the results suggest that in order to avoid IH, AVF should be formed via a vein graft onto a straight artery, or the inner-curvature of a curved artery. We note that the recommendations are incompatible—highlighting the importance of ascertaining the exact mechanisms underlying development of IH in AVF. Nonetheless, the results clearly illustrate the important role played by arterial curvature in determining AVF hemodynamics, which to our knowledge has been overlooked in all previous studies. PMID:25829837

  14. Unusual magnetic and transport properties of oxygen deficient Sr2Fe1-xCoxMoO6-d

    NASA Astrophysics Data System (ADS)

    Chang, Hong; García-Hernández, Mar; Alonso, Jose Antonio

    2006-10-01

    In the title compounds the oxygen voids have a significant influence over the transport properties, compared with the parent stoichiometric compounds (Sr2FeMoO6 and Sr2CoMoO6) where the oxygen defects have little impact on the crystallographic and magnetic properties. For Sr2FeMoO6-d and Sr2Fe0.95Co0.05MoO6-d, the oxygen voids simply decrease the magnetoresistance (MR) without altering the contours, and for x ⩾0.1 at the expense of the decreased low field MR, the oxygen voids enhance MR at high applied field, which is 6%-8% larger than the parent compounds for 0.2⩽x⩽0.7. Remarkably enough, the antiferromagnetic Sr2Fe0.1Co0.9MoO6-d exhibits record negative magnetoresistance ratio MR =((R(H,T)-R(0,T))/R(0,T))×100% as high as 99%.

  15. The role of extracellular histones in haematological disorders.

    PubMed

    Alhamdi, Yasir; Toh, Cheng-Hock

    2016-06-01

    Over the past decades, chromosomal alterations have been extensively investigated for their pathophysiological relevance in haematological malignancies. In particular, epigenetic modifications of intra-nuclear histones are now known as key regulators of healthy cell cycles that have also evolved into novel therapeutic targets for certain blood cancers. Thus, for most haematologists, histones are DNA-chained proteins that are buried deep within chromatin. However, the plot has deepened with recent revelations on the function of histones when unchained and released extracellularly upon cell death or from activated neutrophils as part of neutrophil extracellular traps (NETs). Extracellular histones and NETs are increasingly recognized for profound cytotoxicity and pro-coagulant effects. This article highlights the importance of recognizing this new paradigm of extracellular histones as a key player in host defence through its damage-associated molecular patterns, which could translate into novel diagnostic and therapeutic biomarkers in various haematological and critical disorders. PMID:27062156

  16. Atomic oxygen between 80 and 120 km: Evidence for a rapid spatial variation in vertical transport near the ionosphere

    NASA Technical Reports Server (NTRS)

    Donahue, T. M.; Wasser, B.

    1977-01-01

    Analysis of OGO-6 OI green line photometer results was carried out for 8 cases when the alignment of the spacecraft was such that local emission rates could be determined below the altitude of maximum emission and down to about 80 km. Results show a variation on a scale of 6 deg to 8 deg in latitude between regions where the emission rate increases rapidly between 90 and 95 km and regions where it increases slowly from 80 km to 95 km. Latitude-altitude maps of iso-emissivity contours and iso-density contours for oxygen concentration are presented. The latter are computed under 3 assumptions concerning excitation mechanisms. Comparisons of the spatial variations of oxygen density with the results of a time dependent theory suggest the regions of strong downward transport alternate on a scale of about 1000 km with regions of weak transport near 90 km. In the first case conversion of O to O3 at night appears to be overwhelmed by downward transport of O.

  17. Thermochemical conversion of biomass in smouldering combustion across scales: The roles of heterogeneous kinetics, oxygen and transport phenomena.

    PubMed

    Huang, Xinyan; Rein, Guillermo

    2016-05-01

    The thermochemical conversion of biomass in smouldering combustion is investigated here by combining experiments and modeling at two scales: matter (1mg) and bench (100g) scales. Emphasis is put on the effect of oxygen (0-33vol.%) and oxidation reactions because these are poorly studied in the literature in comparison to pyrolysis. The results are obtained for peat as a representative biomass for which there is high-quality experimental data published previously. Three kinetic schemes are explored, including various steps of drying, pyrolysis and oxidation. The kinetic parameters are found using the Kissinger-Genetic Algorithm method, and then implemented in a one-dimensional model of heat and mass transfer. The predictions are validated with thermogravimetric and bench-scale experiments and then analyzed to unravel the role of heterogeneous reaction. This is the first time that the influence of oxygen on biomass smouldering is explained in terms of both chemistry and transport phenomena across scales. PMID:26901090

  18. Changes in haematological profile of common pheasant (Phasianus colchicus) induced by transit to pheasantry.

    PubMed

    Voslarova, E; Bedanova, I; Vecerek, V; Pistekova, V; Chloupek, P; Suchy, P

    2006-10-01

    The aim of this study was to assess haematological changes in hand-reared pheasants (Phasianus colchicus) transported from intensive housing facilities to a pheasantry. Selected haematological parameters were monitored in a group of 100 pheasants (50 males and 50 females) aged of 9 weeks that were transported for 4 hours by a covered lorry in crates, with a total body weight of 12 +/- 0.5 kg per crate (Group C12 - floor space: 290 cm2/kg) and with a total body weight of 18 +/- 0.5 kg per crate (Group C18 - floor space: 195 cm2/kg). Blood samples were taken from 10 randomly selected males and 10 females before transport (CON group) and 20 hours after transport (C12 and C18 groups). Examinations consisted in determining the total erythrocyte and leukocyte counts, haematocrit values, haemoglobin levels and differential leukocyte counts, whereby the proportions of heterophil, basophil and eosinophil granulocytes, lymphocytes and monocytes of the total leukocytes were computed. The changes in the parameters of red blood cell count were manifested by an increase (P < 0.01) in the haemoglobin level, MCH (mean cell haemoglobin) and MCHC (mean cell haemoglobin concentration) values and a decrease (P < 0.01) in the total erythrocyte count and haematocrit level in both C12 and C18 pheasants, when compared with the control group of non-transported pheasants. C18 pheasants exhibited also a significant increase (P < 0.05) in MCV (mean cell value) value. When analyzing differential leukocyte counts, C18 pheasants showed a decrease (P < 0.01) in heterophil counts and H/L ratio, whereas values in C12 pheasants did not differ from the non-transported control group. Individual counts of lymphocytes were decreased (P < 0.05) in C12 pheasants, whereas basophil counts were increased (P < 0.01) in both C12 and C18 pheasants. Total leukocyte count was decreased (P < 0.01) in C12 and C18 pheasants. In conclusion, the specific requirements of pheasants, as primarily wild animals, for the

  19. Oxygen Dependence and Extravascular Transport of Hypoxia-Activated Prodrugs: Comparison of the Dinitrobenzamide Mustard PR-104A and Tirapazamine

    SciTech Connect

    Hicks, Kevin O. Myint, Hilary; Patterson, Adam V.; Pruijn, Frederik B.; Siim, Bronwyn G.; Patel, Kashyap; Wilson, William R.

    2007-10-01

    Purpose: To compare oxygen dependence and tissue transport properties of a new hypoxia-activated prodrug, PR-104A, with tirapazamine, and to evaluate the implications for antitumor activity when combined with radiotherapy. Methods and Materials: Oxygen dependence of cytotoxicity was measured by clonogenic assay in SiHa cell suspensions. Tissue transport parameters were determined using SiHa multicellular layers. Spatially resolved pharmacokinetic (PK) and pharmacodynamic (PD) models were developed to predict cell killing in SiHa tumors and tested by clonogenic assay 18 h after treatment with the corresponding phosphate ester, PR-104. Results: The K-value (oxygen concentration to halve cytotoxic potency) of PR-104A was 0.126 {+-} 0.021 {mu}M (10-fold lower than tirapazamine at 1.30 {+-} 0.28 {mu}M). The diffusion coefficient of PR-104A in multicellular layers (4.42 {+-} 0.15 x 10{sup -7} cm{sup 2} s{sup -1}) was lower than that of tirapazamine (1.30 {+-} 0.05 x 10{sup -6} cm{sup 2} s{sup -1}) but PK modeling predicted better penetration to hypoxic cells in tumors because of its slower metabolism. The tirapazamine PK/PD model successfully predicted the measured activity in combination with single-dose radiation against SiHa tumors, and the PR-104A model underpredicted the activity, which was greater for PR-104 than for tirapazamine (at equivalent host toxicity) both with radiation and as a single agent. Conclusion: PR-104/PR-104A has different PK/PD properties from tirapazamine and superior activity with single-dose radiotherapy against SiHa xenografts. We have inferred that PR-104A is better able to kill cells at intermediate partial pressure of oxygen in tumors than implied by the PK/PD model, most likely because of a bystander effect resulting from diffusion of its activated metabolites from severely hypoxic zones.

  20. Deposition of Lanthanum Strontium Cobalt Ferrite (LSCF) Using Suspension Plasma Spraying for Oxygen Transport Membrane Applications

    NASA Astrophysics Data System (ADS)

    Fan, E. S. C.; Kesler, O.

    2015-08-01

    Suspension plasma spray deposition was utilized to fabricate dense lanthanum strontium cobalt ferrite oxygen separation membranes (OSMs) on porous metal substrates for mechanical support. The as-sprayed membranes had negligible and/or reversible material decomposition. At the longer stand-off distance (80 mm), smooth and dense membranes could be manufactured using a plasma with power below approximately 81 kW. Moreover, a membrane of 55 μm was observed to have very low gas leakage rates desirable for OSM applications. This thickness could potentially be decreased further to improve oxygen diffusion by using metal substrates with finer surface pores.

  1. Transport dynamics of a high-power-density matrix-type hydrogen-oxygen fuel cell

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.; Hagedorn, N. H.

    1974-01-01

    Experimental transport dynamics tests were made on a space power fuel cell of current design. Various operating transients were introduced and transport-related response data were recorded with fluidic humidity sensing instruments. Also, sampled data techniques were developed for measuring the cathode-side electrolyte concentration during transient operation.

  2. Blood oxygen transport and metabolism of the confined lugworm Arenicola marina (L.).

    PubMed

    Toulmond, A

    1975-12-01

    Oxygen consumption (MO2), haemoglobin oxygen saturation level (SVO2) and pH (pHv) in prebranchial blood were measured in lugworms experimentally confined in sea water at 15 degrees C. Total blood flow through the gills (Vb) was estimated. For sea water oxygen partial pressure (PwO2) between 120 and 150 Torr MO2, SVO2 and Vb were high and nearly constant. For PwO2 less than 120 Torr, Vb fell quickly, MO2 progressively dropped, and metabolism remained aerobic at the expense of the prebrancial blood oxygen store. For PwO2 less than 50 Torr, Vb and SvO2 values were extremely low, and the low pHv and the modified buffer power of the surrounding sea water showed that anaerobic metabolism was occurring. Changes in respiratory gas exchanges and metabolism during the tidal cycle are deduced from the comparison of these results with data obtained in the field. PMID:2646

  3. 78 FR 1765 - Requirements for Chemical Oxygen Generators Installed on Transport Category Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as..., Security Considerations for Lavatory Oxygen Systems (76 FR 12550, March 8, 2011), Docket No. FAA-2011-0186... Airplanes (77 FR 38000, June 26, 2012). Several years ago in an unrelated initiative, the FAA tasked...

  4. Haematology and Serum Biochemistry Parameters and Variations in the Eurasian Beaver (Castor fiber).

    PubMed

    Girling, Simon J; Campbell-Palmer, Roisin; Pizzi, Romain; Fraser, Mary A; Cracknell, Jonathan; Arnemo, Jon; Rosell, Frank

    2015-01-01

    Haematology parameters (N = 24) and serum biochemistry parameters (N = 35) were determined for wild Eurasian beavers (Castor fiber), between 6 months - 12 years old. Of the population tested in this study, N = 18 Eurasian beavers were from Norway and N = 17 originating from Bavaria but now living extensively in a reserve in England. All blood samples were collected from beavers via the ventral tail vein. All beavers were chemically restrained using inhalant isoflurane in 100% oxygen prior to blood sampling. Results were determined for haematological and serum biochemical parameters for the species and were compared between the two different populations with differences in means estimated and significant differences being noted. Standard blood parameters for the Eurasian beaver were determined and their ranges characterised using percentiles. Whilst the majority of blood parameters between the two populations showed no significant variation, haemoglobin, packed cell volume, mean cell haemoglobin and white blood cell counts showed significantly greater values (p<0.01) in the Bavarian origin population than the Norwegian; neutrophil counts, alpha 2 globulins, cholesterol, sodium: potassium ratios and phosphorus levels showed significantly (p<0.05) greater values in Bavarian versus Norwegian; and potassium, bile acids, gamma globulins, urea, creatinine and total calcium values levels showed significantly (p<0.05) greater values in Norwegian versus Bavarian relict populations. No significant differences were noted between male and female beavers or between sexually immature (<3 years old) and sexually mature (≥3 years old) beavers in the animals sampled. With Eurasian beaver reintroduction encouraged by legislation throughout Europe, knowledge of baseline blood values for the species and any variations therein is essential when assessing their health and welfare and the success or failure of any reintroduction program. This is the first study to produce base

  5. Oxygen transport in the Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} system.

    SciTech Connect

    Ma, B.

    1999-01-04

    The mixed-conducting Sr-Fe-Co oxide has potential use as a gas separation membrane. Its superior oxygen transport reveals the feasibility of using oxide membranes in large-scale oxygen separation. Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0.0, 0.3, 0.6, and 1.0) samples were made by solid state reaction. To understand the oxygen transport mechanism in this system, conductivity and thermogravimetry experiments were conducted at high temperature in various oxygen partial pressure environments. The oxygen diffusion coefficient was determined from the time relaxation transient behavior of the specimen after switching the surrounding atmosphere. Mobility of the charge carrier was derived from relative conductivity and weight changes. X-ray diffraction experiments were carried out on these samples to determine their crystal structures.

  6. Two-dimensional concentration distribution of reactive oxygen species transported through a tissue phantom by atmospheric-pressure plasma-jet irradiation

    NASA Astrophysics Data System (ADS)

    Kawasaki, Toshiyuki; Sato, Akihiro; Kusumegi, Shota; Kudo, Akihiro; Sakanoshita, Tomohiro; Tsurumaru, Takuya; Uchida, Giichiro; Koga, Kazunori; Shiratani, Masaharu

    2016-07-01

    The two-dimensional concentration distribution of reactive oxygen species (ROSs) transported through an agarose-film tissue phantom by atmospheric-pressure plasma-jet irradiation is visualized using a KI-starch gel reagent. Oxygen addition to helium enhances ROS transportation through the film. A radial ROS distribution pattern at the plasma-irradiated film surface changes into a doughnut-shaped pattern after passing through the film. The ROS transportation speed is 0.14–0.2 mm/min. We suggest that there are two types of ROS transportation pathways in the plasma-irradiated film: linear and circular. The majority of ROSs are transported through the circular pathway. ROS concentration distributions changed markedly with irradiation distance. Diffusive ROS transportation due to a concentration gradient is negligible in plasma-irradiated films.

  7. Avoiding chromium transport from stainless steel interconnects into contact layers and oxygen electrodes in intermediate temperature solid oxide electrolysis stacks

    NASA Astrophysics Data System (ADS)

    Schlupp, Meike V. F.; Kim, Ji Woo; Brevet, Aude; Rado, Cyril; Couturier, Karine; Vogt, Ulrich F.; Lefebvre-Joud, Florence; Züttel, Andreas

    2014-12-01

    We investigated the ability of (La0.8Sr0.2)(Mn0.5Co0.5)O3-δ (LSMC) and La(Ni0.6Fe0.4)O3-δ (LNF) contact coatings to avoid the transport of Cr from steel interconnects to solid oxide electrolysis electrodes, especially to the anode. The transport of chromium from commercial Crofer 22 APU (ThyssenKrupp) and K41X (AISI441, Aperam Isbergues) steels through LSMC and LNF contact coatings into adjacent (La0.8Sr0.2)MnO3-δ (LSM) oxygen electrodes was investigated in an oxygen atmosphere at 700 °C. Chromium concentrations of up to 4 atom% were detected in the contact coatings after thermal treatments for 3000 h, which also lead to the presence of chromium in adjacent LSM electrodes. Introduction of a dense (Co,Mn)3O4 coating between steel and contact coating was necessary to prevent the diffusion of chromium into contact coatings and electrodes and should lead to extended stack performance and lifetime.

  8. Misconceptions concerning the behavior, fate and transport of the fuel oxygenates TBA and MTBE

    NASA Astrophysics Data System (ADS)

    Woodward, R.; Sloan, R.

    2003-04-01

    The release of gasoline from underground storage tanks and the subsequent appearance of dissolved constituents in drinking water has focused attention on the use of MTBE in reformulated fuels. Natural biodegradation of MTBE in soil, photo-oxidation in the atmosphere or chemical oxidation during remediation of gasoline releases can produce the intermediate tertiary butyl alcohol (TBA). TBA is also a fuel oxygenate and can be found as a co-product in MTBE synthesized from methanol and TBA. Because the physical properties of ethers and alcohols differ somewhat from the predominant hydrocarbon compounds in gasoline, misconceptions have developed about the behavior of fuel oxygenates in storage and in the subsurface. Critical review of several misconceptions about MTBE and TBA in gasoline reveals the concepts were conceived to rationalize early field observations and/or incomplete data sets. Closer scrutiny, in light of recent laboratory investigations, field data, case studies and world literature, clarifies these misconceptions and assumptions about the behavior of ether oxygenates and their degradation products in the environment. Commonly held misconceptions focus on four general areas of fuel and fuel oxygenate management: storage/dispensing, hydrology, remediation, and health effects. Storage/dispensing misconceptions address materials stability to ethers and alcohols in fuel and the environmental forensics of fuel systems failure. Groundwater and hydrology misconceptions deal with plume dynamics and the impact of fuel on drinking water resources. Remediation misconceptions focus on the performance of traditional hydrocarbon remediation technologies, recent developments in biodegradation and natural attenuation, drivers of remedial design and remediation costs. Health effects misconceptions address both acute and chronic exposure risk evaluations by national and international health agencies. Generally MTBE and TBA are manageable by the same processes and

  9. Direct Evidence of Solution-Mediated Superoxide Transport and Organic Radical Formation in Sodium-Oxygen Batteries.

    PubMed

    Xia, Chun; Fernandes, Russel; Cho, Franklin H; Sudhakar, Niranjan; Buonacorsi, Brandon; Walker, Sean; Xu, Meng; Baugh, Jonathan; Nazar, Linda F

    2016-09-01

    Advanced large-scale electrochemical energy storage requires cost-effective battery systems with high energy densities. Aprotic sodium-oxygen (Na-O2) batteries offer advantages, being comprised of low-cost elements and possessing much lower charge overpotential and higher reversibility compared to their lithium-oxygen battery cousins. Although such differences have been explained by solution-mediated superoxide transport, the underlying nature of this mechanism is not fully understood. Water has been suggested to solubilize superoxide via formation of hydroperoxyl (HO2), but direct evidence of these HO2 radical species in cells has proven elusive. Here, we use ESR spectroscopy at 210 K to identify and quantify soluble HO2 radicals in the electrolyte-cold-trapped in situ to prolong their lifetime-in a Na-O2 cell. These investigations are coupled to parallel SEM studies that image crystalline sodium superoxide (NaO2) on the carbon cathode. The superoxide radicals were spin-trapped via reaction with 5,5-dimethyl-pyrroline N-oxide at different electrochemical stages, allowing monitoring of their production and consumption during cycling. Our results conclusively demonstrate that transport of superoxide from cathode to electrolyte leads to the nucleation and growth of NaO2, which follows classical mechanisms based on the variation of superoxide content in the electrolyte and its correlation with the crystallization of cubic NaO2. The changes in superoxide content upon charge show that charge proceeds through the reverse solution process. Furthermore, we identify the carbon-centered/oxygen-centered alkyl radicals arising from attack of these solubilized HO2 species on the diglyme solvent. This is the first direct evidence of such species, which are likely responsible for electrolyte degradation. PMID:27498623

  10. Role of hemoglobin from blood clam Scapharca kagoshimensis beyond oxygen transport.

    PubMed

    Xu, Bin; Zhao, Jun; Jing, Zhao; Zhang, Yanan; Shi, Ying; Fan, Tingjun

    2015-05-01

    The evolutionary race between hosts and pathogens has led to a variety of adaptations. Little is known about the immunological role of hemoglobin (Hb) in antimicrobial immune responses. Results showed that a 31.2 kDa monodimer Hb (skHbI) and a 57.8 kDa heterotetramer Hb (skHbII) from the blood clam, Scapharca kagoshimensis, had phenoloxidase (PO)-like activities and antimicrobial activities. Both were found capable of oxidizing l-DOPA, catechol and hydroquinone. Their PO-like activities were visibly greatly inhibited by oxidase inhibitors, EDTA, and divalent metal ions, and greatly enhanced by isopropanol and Fe(2+), indicating that they have the properties of a metalloenzyme and a catecholase-type PO as well. They also showed obvious anti-bacterial activities against gram-positive bacteria but not against either gram-negative bacteria nor fungi. The anti-bacterial activities levels were a result of the generation of reactive oxygen species (ROS) of superoxide anions. These results indicate that skHbI and skHbII, not only function as iron-containing oxygen carriers, but also exert anti-bacterial activities and catecholase-type oxidizing activities. The fact that skHbII exerts high level of PO-like activity indicates different roles in the innate immunodefense system. These results may improve understanding of the multiple functions of invertebrate Hbs beyond serving as oxygen carriers and may provide insight into how the fundamental and universal mode of the innate immune system has persisted in respiratory proteins throughout the course of evolution. PMID:25700784

  11. Electrical transport properties of individual WS2 nanotubes and their dependence on water and oxygen absorption

    NASA Astrophysics Data System (ADS)

    Zhang, Chaoying; Ning, Zhiyuan; Liu, Yang; Xu, Tingting; Guo, Yao; Zak, Alla; Zhang, Zhiyong; Wang, Sheng; Tenne, Reshef; Chen, Qing

    2012-09-01

    The electrical properties of WS2 nanotubes (NTs) were studied through measuring 59 devices. Important electrical parameters, such as the carrier concentration, mobility, and effective barrier height at the contacts, were obtained through fitting experimental non-linear I-V curves using a metal-semiconductor-metal model. The carrier mobility was found to be several orders of magnitude higher than that have been reported previously for WS2 NTs. Water absorption was found to decrease the conductivity and carrier mobility of the NTs, and could be removed when the sample was dried. Oxygen absorption also slightly decreased the conductivity of WS2 NTs.

  12. Fluorination of an antiepileptic drug: A self supporting transporter by oxygen enrichment mechanism.

    PubMed

    Natchimuthu, V; Amoros, J; Ravi, S

    2016-03-01

    Drug therapy of seizures involves producing high levels of antiepileptic drugs in the blood. Drug must enter the brain by crossing from the blood into the brain tissue, called a transvascular route (TVR). Even before the drug can reach the brain tissue, factors such as systemic toxicity, macrophage phagocytises and reduction in oxygen content limit the success of this TVR. Encapsulating the drug within a nano scale delivering system, synthesising drugs with low molecular weight are the best mechanisms to deliver the drug to the brain. But through this article, we have explored a possibility of attaching a molecule 4-(trifluoromethyl) benzoic acid (TFMBA), that possess more number of fluorine atom, to benzodiazepine (BDZ) resulting in an ionic salt (S)-(+)-2,3-dihydro-1H-pyrrolo[2,1-c][1,4]benzodiazepine5,11(10H,11aH)-dione with 4-(trifluoromethyl)benzoic acid. By this way, reducing the toxicity of BDZ than the conventional anti-epileptic drugs (AEDs), increasing the solubility, reducing the melting point, enriching the TVR with excess oxygen content with the support of fluorine. With all these important prerequisites fulfilled, the drug along with the attached molecule is expected to travel more comfortably through the TVR without any external support than any other conventional AEDs. FTIR, (1)H NMR, (13)C NMR, HRMS spectroscopy, HRTEM and In vitro cytotoxicity analysis supports this study. PMID:26708322

  13. Haematological profile in leprosy. Part I--general findings.

    PubMed

    Karat, A B; Rao, P S

    1977-04-01

    Haematological studies in 904 adult leprosy patients with different types of leprosy, in various stages of the disease and treatment are described. Haemoglobin, packed cell volume, serum albumin and serum iron are significantly lower among lepromatous leprosy patients as compared with non-lepromatous patients. The serum B12 levels were significantly higher among the lepromatous group. Acid fast bacilli have been demonstrated in skin smear negative leprosy patients with indeterminate and tuberculoid leprosy, suggesting occurrence of bacillaemia in these groups of patients. PMID:909286

  14. Transition of care from paediatric to adult services in haematology

    PubMed Central

    Bolton‐Maggs, Paula H B

    2007-01-01

    The need for adequate preparation for transition for young people with health care needs who require long term follow‐up in the adult sector has long been recognised and is a required part of the national service framework for children. The Royal College of Paediatrics and Child Health and the Royal College of Nursing have endorsed this need for improvement in services for adolescents. In 2006 the Department of Health launched guidelines with a wealth of recommendations. Despite these initiatives only slow progress has been made (usually by enthusiasts) and much work is needed to develop good programmes in many specialties, including non‐malignant haematology. PMID:17715443

  15. Haematological parameters as bioindicators of insecticide exposure in teleosts.

    PubMed

    Singh, Narendra Nath; Srivastava, Anil Kumar

    2010-06-01

    Haematological parameters, such as erythrocyte and leucocyte count, erythrocyte indices and thrombocyte number vis-a-vis coagulation of blood has been considered bioindicators of toxicosis in fish following exposure to organochlorine, organophosphate, carbamate and pyrethroid insecticides. This review deals with the effects of insecticides on the morphology of red blood cells, total erythrocyte count, haemoglobin content, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, erythrocyte sedimentation rate, total and differential leucocyte counts, thrombocyte count and clotting time in the peripheral blood of a number of teleosts. The review also takes stock of knowledge of the subject and explores prospects of additional research in the related area. PMID:20177774

  16. Re-evaluation of the H+/site ratio of mitochondrial electron transport with the oxygen pulse technique.

    PubMed

    Brand, M D; Reynafarje, B; Lehninger, A L

    1976-09-25

    The number of protons ejected per pair of electrons passing each energy-conserving site in the electron transport chain (the H+/site ratio) has been investigated in rat liver mitochondria by means of the oxygen pulse technique introduced by Mitchell and Moyle (1967) (Biochem. J. 105, 1147-1162). The usual H+/site values of 2.0 observed by this method were found to be substantially underestimated as a result of the influx of phosphate into the mitochondria. This was shown by three different kinds of experiments. 1. Addition of N-ethylmaleimide or mersalyl, inhibitors of mitochondrial phosphate transport, increased the H+/site ratio from 2.0 to 3.0. The dependence of this effect on the concentration of either inhibitor was identical with that for inhibition of phosphate transport. Added phosphate diminished the H+/site ratio to values below 2.0 in the absence of N-ethylmaleimide. N-Ethylmaleimide protected the elevated H+/site ratio of 3.0 against the deleterious effect of added phosphate, but did not prevent a lowering effect of weak acid anions such as 3-hydroxybutyrate. 2. Prior washing of mitochondria to remove the endogenous phosphate that leaks out during the anaerobic preincubation led to H+/site ratios near 3.0, which were not increased by N-ethylmaleimide. Addition of low concentrations of phosphate to such phosphate-depleted mitochondria decreased the H+/site ratio to 2.0; addition of N-ethylmaleimide returned the ratio to 3.0. 3. Lowering the temperature to 5 degrees, which slows down phosphate transport, led to H+/site values of 3.0 even in the absence of N-ethylmaleimide. The H+/site ratio of 3.0 observed in the absence of phosphate movements was not dependent on any narrowly limited set of experimental conditions. It occurred with either Ca2+ or K+ (in the presence of valinomycin) as mobile permeant cation. It was independent of the concentration of succinate, oxygen, mitochondria, or rotenone, additions of Ca2+, Li+, or Na+ and was independent of

  17. Negative ion clusters in oxygen: collision cross sections and transport coefficients

    NASA Astrophysics Data System (ADS)

    de Urquijo, J.; Bekstein, A.; Ducasse, O.; Ruíz-Vargas, G.; Yousfi, M.; Benhenni, M.

    2009-12-01

    Using a pulsed Townsend experiment, we have observed the formation of two negative ion species in oxygen over the pressure range 100-600 torr, and the density-normalised electric field strength, E/N, from 2 to 14 Td. The peculiar shape of these transients has led us to propose a scheme of three-body ion-molecule reactions leading to the formation of O4 - and O6 -, which is substantiated by a curve fitting procedure. The resulting mobility data of these two ionic species have been used to calculate their respective momentum transfer collision cross sections, together with the dissociation cross sections that are needed to extend the range of calculation of mobility and diffusion (transverse and longitudinal) to 1000 Td. These calculations were based on an optimised Monte Carlo algorithm, using collision cross sections obtained from a JWKB approximation (Jeffreys-Wentzel-Kramers-Brillouin) or taken from literature.

  18. Reversible modulation of electric transport properties by oxygen absorption and releasing on Nb:SrTiO{sub 3} surface

    SciTech Connect

    Lu, H. X.; Liu, Y. B.; Chen, Y. S. Wang, J.; Shen, B. G.; Sun, J. R.

    2014-11-07

    Pt Schottky contacts on (001)-orientated Nb-doped SrTiO{sub 3} (NSTO) in both ambient air and vacuum were investigated by the conductive atomic force microscope. The co-existed TiO{sub 2} and SrO termination layers were identified on the terrace-structured NSTO surface, where the former possessed a higher forward current than the latter. In ambient air, the barrier height of Pt/NSTO Schottky junction exhibited periodical variation with cyclic terrace plane and step sites, whereas it became homogeneous in ambient vacuum. We suggested that the oxygen absorption and releasing of surface dangling bonds were the origin for reversible changes in transport properties, which indicates a feasible approach for the surface modulation and band structure tailoring of NSTO based heterojunctions.

  19. Reversible modulation of electric transport properties by oxygen absorption and releasing on Nb:SrTiO3 surface

    NASA Astrophysics Data System (ADS)

    Lu, H. X.; Liu, Y. B.; Chen, Y. S.; Wang, J.; Shen, B. G.; Sun, J. R.

    2014-11-01

    Pt Schottky contacts on (001)-orientated Nb-doped SrTiO3 (NSTO) in both ambient air and vacuum were investigated by the conductive atomic force microscope. The co-existed TiO2 and SrO termination layers were identified on the terrace-structured NSTO surface, where the former possessed a higher forward current than the latter. In ambient air, the barrier height of Pt/NSTO Schottky junction exhibited periodical variation with cyclic terrace plane and step sites, whereas it became homogeneous in ambient vacuum. We suggested that the oxygen absorption and releasing of surface dangling bonds were the origin for reversible changes in transport properties, which indicates a feasible approach for the surface modulation and band structure tailoring of NSTO based heterojunctions.

  20. Apoplasmic Barriers and Oxygen Transport Properties of Hypodermal Cell Walls in Roots from Four Amazonian Tree Species1

    PubMed Central

    De Simone, Oliviero; Haase, Karen; Müller, Ewald; Junk, Wolfgang J.; Hartmann, Klaus; Schreiber, Lukas; Schmidt, Wolfgang

    2003-01-01

    The formation of suberized and lignified barriers in the exodermis is suggested to be part of a suite of adaptations to flooded or waterlogged conditions, adjusting transport of solutes and gases in and out of roots. In this study, the composition of apoplasmic barriers in hypodermal cell walls and oxygen profiles in roots and the surrounding medium of four Amazon tree species that are subjected to long-term flooding at their habitat was analyzed. In hypodermal cell walls of the deciduous tree Crateva benthami, suberization is very weak and dominated by monoacids, 2-hydroxy acids, and ω-hydroxycarboxylic acids. This species does not show any morphological adaptations to flooding and overcomes the aquatic period in a dormant state. Hypodermal cells of Tabernaemontana juruana, a tree which is able to maintain its leaf system during the aquatic phase, are characterized by extensively suberized walls, incrusted mainly by the unsaturated C18 ω-hydroxycarboxylic acid and the α,ω-dicarboxylic acid analogon, known as typical suberin markers. Two other evergreen species, Laetia corymbulosa and Salix martiana, contained 3- to 4-fold less aliphatic suberin in the exodermis, but more than 85% of the aromatic moiety of suberin are composed of para-hydroxybenzoic acid, suggesting a function of suberin in pathogen defense. No major differences in the lignin content among the species were observed. Determination of oxygen distribution in the roots and rhizosphere of the four species revealed that radial loss of oxygen can be effectively restricted by the formation of suberized barriers but not by lignification of exodermal cell walls. PMID:12746526

  1. Apoplasmic barriers and oxygen transport properties of hypodermal cell walls in roots from four amazonian tree species.

    PubMed

    De Simone, Oliviero; Haase, Karen; Müller, Ewald; Junk, Wolfgang J; Hartmann, Klaus; Schreiber, Lukas; Schmidt, Wolfgang

    2003-05-01

    The formation of suberized and lignified barriers in the exodermis is suggested to be part of a suite of adaptations to flooded or waterlogged conditions, adjusting transport of solutes and gases in and out of roots. In this study, the composition of apoplasmic barriers in hypodermal cell walls and oxygen profiles in roots and the surrounding medium of four Amazon tree species that are subjected to long-term flooding at their habitat was analyzed. In hypodermal cell walls of the deciduous tree Crateva benthami, suberization is very weak and dominated by monoacids, 2-hydroxy acids, and omega-hydroxycarboxylic acids. This species does not show any morphological adaptations to flooding and overcomes the aquatic period in a dormant state. Hypodermal cells of Tabernaemontana juruana, a tree which is able to maintain its leaf system during the aquatic phase, are characterized by extensively suberized walls, incrusted mainly by the unsaturated C(18) omega-hydroxycarboxylic acid and the alpha,omega-dicarboxylic acid analogon, known as typical suberin markers. Two other evergreen species, Laetia corymbulosa and Salix martiana, contained 3- to 4-fold less aliphatic suberin in the exodermis, but more than 85% of the aromatic moiety of suberin are composed of para-hydroxybenzoic acid, suggesting a function of suberin in pathogen defense. No major differences in the lignin content among the species were observed. Determination of oxygen distribution in the roots and rhizosphere of the four species revealed that radial loss of oxygen can be effectively restricted by the formation of suberized barriers but not by lignification of exodermal cell walls. PMID:12746526

  2. The Ca2+/Mn2+-transporting SPCA2 pump is regulated by oxygen and cell density in colon cancer cells.

    PubMed

    Jenkins, James; Papkovsky, Dmitri B; Dmitriev, Ruslan I

    2016-08-15

    The mammalian SPCA1 and SPCA2 ATPases localize in membranes of the secretory pathway and transport ions of Ca(2+) and Mn(2+) The role of tissue-specific SPCA2 isoform, highly expressed in lungs, mammary gland and gastrointestinal tract, is poorly understood. To elucidate the function of SPCA2, we studied human colon cancer HCT116 cells, grown under ambient and decreased O2 levels. We found that in contrast with other Ca(2+)-ATPase isoforms the expression of SPCA2 was up-regulated under hypoxia (3% O2), in both adherent (2D) and spheroid (3D) cultures. In spheroids, experiencing lowest O2 levels (30-50 μM, measured by phosphorescence lifetime imaging microscopy), we observed lower staining with reactive oxygen species (ROS)-specific fluorescent probe, which correlated with increased SPCA2. However, SPCA2 expression was up-regulated in cells exposed to reactive oxygen and nitrogen species donors, and when grown at higher density. We noticed that the culture exposed to hypoxia showed overall increase in S phase-positive cells and hypothesized that SPCA2 up-regulation under hypoxia can be linked to Mn(2+)-dependent cell cycle arrest. Consequently, we found that SPCA2-transfected cells display a higher number of cells entering S phase. Altogether, our results point at the important role of SPCA2 in regulation of cell cycle in cancer cells. PMID:27316461

  3. The Role of miRNA in Haematological Malignancy

    PubMed Central

    Gounaris-Shannon, Stephanie

    2013-01-01

    Currently, there are over 1,800 annotated human miRNAs, many of which have tissue-specific expression. Numerous studies have highlighted their role in haematopoietic differentiation and proliferation, acting as master regulators of haematopoietic stem cell function. Aberrant expression of miRNAs has been observed in haematological cancers, exhibiting unique expression signatures in comparison to normal counterparts. Functional and target analyses as well as animal models have attempted to annotate how different miRNA may contribute to the pathophysiology of these malignancies from modulating cancer associated genes, functioning directly as oncogenes or tumour suppressor genes or acting as bystanders or regulators of the epigenetic mechanisms in cancer. miRNAs have also been shown to play a role in modulating drug resistance and determining prognosis between the various subtypes of blood cancers. This review discusses the important role that miRNAs play in haematological malignancies by exploring associations that exist between the two and trying to examine evidence of causality to support the tantalising possibility that miRNAs might serve as therapeutic targets in blood cancers. PMID:24416592

  4. Long Non-Coding RNAs in Haematological Malignancies

    PubMed Central

    Garitano-Trojaola, Andoni; Agirre, Xabier; Prósper, Felipe; Fortes, Puri

    2013-01-01

    Long non-coding RNAs (lncRNAs) are functional RNAs longer than 200 nucleotides in length. LncRNAs are as diverse as mRNAs and they normally share the same biosynthetic machinery based on RNA polymerase II, splicing and polyadenylation. However, lncRNAs have low coding potential. Compared to mRNAs, lncRNAs are preferentially nuclear, more tissue specific and expressed at lower levels. Most of the lncRNAs described to date modulate the expression of specific genes by guiding chromatin remodelling factors; inducing chromosomal loopings; affecting transcription, splicing, translation or mRNA stability; or serving as scaffolds for the organization of cellular structures. They can function in cis, cotranscriptionally, or in trans, acting as decoys, scaffolds or guides. These functions seem essential to allow cell differentiation and growth. In fact, many lncRNAs have been shown to exert oncogenic or tumor suppressor properties in several cancers including haematological malignancies. In this review, we summarize what is known about lncRNAs, the mechanisms for their regulation in cancer and their role in leukemogenesis, lymphomagenesis and hematopoiesis. Furthermore, we discuss the potential of lncRNAs in diagnosis, prognosis and therapy in cancer, with special attention to haematological malignancies. PMID:23887658

  5. Immunophenotyping of Posttraumatic Neutrophils on a Routine Haematology Analyser

    PubMed Central

    Groeneveld, Kathelijne Maaike; Heeres, Marjolein; Leenen, Loek Petrus Hendrikus; Huisman, Albert; Koenderman, Leo

    2012-01-01

    Introduction. Flow cytometry markers have been proposed as useful predictors for the occurrence of posttraumatic inflammatory complications. However, currently the need for a dedicated laboratory and the labour-intensive analytical procedures make these markers less suitable for clinical practice. We tested an approach to overcome these limitations. Material and Methods. Neutrophils of healthy donors were incubated with antibodies commonly used in trauma research: CD11b (MAC-1), L-selectin (CD62L), FcγRIII (CD16), and FcγRII (CD32) in active form (MoPhab A27). Flow cytometric analysis was performed both on a FACSCalibur, a standard flow cytometer, and on a Cell-Dyn Sapphire, a routine haematology analyser. Results. There was a high level of agreement between the two types of analysers, with 41% for FcγRIII, 80% for L-selectin, 98% for CD11b, and even a 100% agreement for active FcγRII. Moreover, analysis on the routine haematology analyser was possible in less than a quarter of the time in comparison to the flow cytometer. Conclusion. Analysis of neutrophil phenotype on the Cell-Dyn Sapphire leads to the same conclusion compared to a standard flow cytometer. The markedly reduced time necessary for analysis and reduced labour intensity constitutes a step forward in implementation of this type of analysis in clinical diagnostics in trauma research. PMID:22523451

  6. Cerebrovascular disease as the initial clinical presentation of haematological disorders.

    PubMed

    Arboix, A; Besses, C

    1997-01-01

    We describe 14 patients (mean age 57 years) in whom stroke or TIA was the presenting manifestation of a haematologic disorder. Twelve patients had an ischaemic stroke and 2 a haemorrhagic stroke. This group represented 1.27% (14/1,099) of the total number of patients with first-ever stroke diagnosed from 1986 to 1992 at our institution, accounted for 1.32% (12/906) of all brain infarcts and 1.03% (2/193) of all haemorrhagic strokes, and was the most common aetiology (25%) of ischaemic stroke of unusual cause. Haematological disorders included essential thrombocythaemia (6), polycythaemia vera (1), smoker's polycythaemia (1), thrombotic thrombocytopenic purpura (1), IgA lambda myeloma (1), acute lymphoblastic leukaemia (1), Waldenström's macroglobulinaemia (1), chronic granulocytic leukaemia (1) and IgG lambda myeloma (1). Stroke subtypes included definitive cerebral infarct (10), TIA (2), parenchymal haemorrhage (1) and spontaneous subdural haematoma (1). Vascular territories in ischaemic stroke were the carotid in 7 patients, the vertebrobasilar in 1 and undetermined in 4. Mean follow-up was 40 months (range, 1-96 months). The mortality rate was 18.7%. PMID:9208259

  7. Haematological investigation of a multiple case leucosis herd.

    PubMed

    Dimmock, C K; Waugh, P D; Rogers, R J

    1979-06-01

    Adult cattle in a Queensland dairy herd with a history of deaths from lymphosarcoma were sampled regularly over a 4 year period for the identification of animals with persistent lymphocytosis (PL). Twenty-one of 94 animals that were sampled at least 6 times had PL. At the initial sampling 27% of the animals had lymphocytosis. Culling of haematologically positive animals in the first 18 months of the investigation reduced this to 5.3%, but cessation of the culling programme resulted in a gradual increase in the percentage of animals with lymphocytosis. Four deaths from lymphosarcoma occurred in adult animals, but only in the first 18 months of the investigation. Two of these animals had lymphocytosis and two lymphoblastic leukaemia. The calf of one of the latter cows developed lymphoblastic leukaemia and lymphosarcoma by the time it was 6 months of age. Although histological evidence of lymphosarcoma was lacking in a number of clinically normal animals with lymphocytosis, haematological investigation identified a group of animals within the herd that may develop lymphosarcoma. PMID:293162

  8. Communication during haematological consultations; patients' preferences and professionals' performances.

    PubMed

    van Bruinessen, Inge R; van der Hout, Lotte E; van Weel-Baumgarten, Evelyn M; Gouw, Hans; Zijlstra, Josée M; van Dulmen, Sandra

    2016-06-01

    Many patients with haematological malignancies experience barriers in clinical communication. Reaching effective communication is of great importance as it has been linked to a range of improved patient outcomes such as satisfaction, compliance to treatment, perceived quality of life and physical and mental health. To get a better understanding how communication in haematological consultations can be improved, the current study focussed on patients' preferences and perceived performances regarding the communicative behaviour of their health care professional. Secondly, the mediation of an online communication tool for patients was analysed. Within a controlled pre- post-test design, 78 datasets of clinical consultations could be analysed. Patients considered both affective and instrumental communication aspects important. The affective communication behaviour of the health care professional met the patients' pre-visit preferences well. In the information exchange, more variability and discrepancies were found. Overall, the online intervention did not seem to influence the patients' perceived communication performance of their health care professional much. To further improve the communication during clinical consultations, health care professionals should inquire about patients' expectations, especially during the exchange of information and advices. At the same time, patients should be supported to express their preferences at the start of the consultation. The study was registered in the Netherlands Trial Register, number 3779. PMID:27091348

  9. Optical methods for correction of oxygen-transport characteristics of blood and their biomedical applications

    NASA Astrophysics Data System (ADS)

    Zalesskaya, G. A.; Akulich, N. V.; Marochkov, A. V.; Laskina, O. V.; Mit'kovskaya, N. P.

    2010-07-01

    We have carried out a comprehensive analysis of the spectral characteristics of blood and blood components, gas-exchange and oximetry parameters for venous and arterial blood, central hemodynamic parameters, and the results of a complete blood count and chemistry panel before and after extracorporeal UV irradiation of the blood (UBI, ultraviolet blood irradiation) or intravenous exposure of blood to low-intensity emission from an He-Ne laser (LBI, laser blood irradiation). We have demonstrated the possibility of correcting the oxygentransport characteristics of blood by laser optical methods based on photodissociation of blood oxyhemoglobin. We have shown that the therapeutic effects initiated both by UBI and LBI are based on a single mechanism: a change in the balance between production of active oxygen species and their inhibition by antioxidants. The data obtained are of interest not only for studying the primary (molecular) mechanisms of action for photohemotherapy and their effect on processes occurring in the living body, but also can provide a basis for designing next-generation laser optical instruments and for development of not yet existing methods for assessing the therapeutic efficacy of photohemotherapy.

  10. Transport properties for liquid silicon-oxygen-iron mixtures at Earth's core conditions

    NASA Astrophysics Data System (ADS)

    Pozzo, Monica; Davies, Chris; Gubbins, David; Alfè, Dario

    2013-01-01

    We report on the thermal and electrical conductivities of two liquid silicon-oxygen-iron mixtures (Fe0.82Si0.10O0.08 and Fe0.79Si0.08O0.13), representative of the composition of the Earth's outer core at the relevant pressure-temperature conditions, obtained from density functional theory calculations with the Kubo-Greenwood formulation. We find thermal conductivities k=100(160) W m-1 K-1, and electrical conductivities σ=1.1(1.3)×106Ω-1 m-1 at the top (bottom) of the outer core. These values are between two and three times higher than previous estimates, and have important implications for our understanding of the Earth's thermal history and the functioning of the Earth's magnetic field, including rapid cooling rate for the whole core or high level of radiogenic elements in the core. We also show results for a number of structural and dynamic properties of the mixtures, including the partial radial distribution functions, mean square displacements, viscosities, and speeds of sound.

  11. Effect of intermittent hypoxia and exercise on blood rheology and oxygen transport in trained rats.

    PubMed

    Núñez-Espinosa, Cristian; Douziech, Anne; Ríos-Kristjánsson, Juan Gabriel; Rizo, David; Torrella, Joan Ramon; Pagès, Teresa; Viscor, Ginés

    2014-02-01

    Intermittent hypobaric hypoxia (IHH) exposure, accompanied or not with active recovery, can help to skeletal muscle repair. However, the erythropoietic response elicited can disturb blood rheology and thus alter the oxygen delivery to tissues. Male Sprague-Dawley rats were studied in two basal states: untrained and trained and compared with early (1-3 days) and late (7-14 days) stages of damage recovery in three groups of trained rats that had suffered skeletal muscle injury: Control, passive recovery rats; HYP, rats exposed to IHH after muscle damage; and EHYP, trained rats that performed light aerobic exercise sessions in addition to IHH. Hematocrit, RBC count and hemoglobin were only elevated in the late stage of recovery in HYP (13%; 14% and 8%) and EHYP (18%; 13% and 15%) groups. Blood viscosity increased about double for EHYP rats. It is concluded that intermittent exposure to hypobaric hypoxia in combination with light aerobic exercise in normoxia has an erythropoietic effect, but also provides advantageous hemorheological conditions for the perfusion of damaged muscle. PMID:24373840

  12. Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients

    PubMed Central

    Abe, Daijiro; Fukuoka, Yoshiyuki; Horiuchi, Masahiro

    2015-01-01

    The oxygen cost of transport per unit distance (CoT; mL·kg-1·km-1) shows a U-shaped curve as a function of walking speed (v), which includes a particular walking speed minimizing the CoT, so called economical speed (ES). The CoT-v relationship in running is approximately linear. These distinctive walking and running CoT-v relationships give an intersection between U-shaped and linear CoT relationships, termed the energetically optimal transition speed (EOTS). This study investigated the effects of subtracting the standing oxygen cost for calculating the CoT and its relevant effects on the ES and EOTS at the level and gradient slopes (±5%) in eleven male trained athletes. The percent effects of subtracting the standing oxygen cost (4.8 ± 0.4 mL·kg-1·min-1) on the CoT were significantly greater as the walking speed was slower, but it was not significant at faster running speeds over 9.4 km·h-1. The percent effect was significantly dependent on the gradient (downhill > level > uphill, P < 0.001). The net ES (level 4.09 ± 0.31, uphill 4.22 ± 0.37, and downhill 4.16 ± 0.44 km·h-1) was approximately 20% slower than the gross ES (level 5.15 ± 0.18, uphill 5.27 ± 0.20, and downhill 5.37 ± 0.22 km·h-1, P < 0.001). Both net and gross ES were not significantly dependent on the gradient. In contrast, the gross EOTS was slower than the net EOTS at the level (7.49 ± 0.32 vs. 7.63 ± 0.36 km·h-1, P = 0.003) and downhill gradients (7.78 ± 0.33 vs. 8.01 ± 0.41 km·h-1, P < 0.001), but not at the uphill gradient (7.55 ± 0.37 vs. 7.63 ± 0.51 km·h-1, P = 0.080). Note that those percent differences were less than 2.9%. Given these results, a subtraction of the standing oxygen cost should be carefully considered depending on the purpose of each study. PMID:26383249

  13. Proline Modulates the Trypanosoma cruzi Resistance to Reactive Oxygen Species and Drugs through a Novel D, L-Proline Transporter

    PubMed Central

    Sayé, Melisa; Miranda, Mariana R.; di Girolamo, Fabio; de los Milagros Cámara, María; Pereira, Claudio A.

    2014-01-01

    Trypanosoma cruzi, the etiological agent of Chagas' disease, has a metabolism largely based on the consumption of glucose and proline. This amino acid is essential for host cells infection and intracellular differentiation. In this work we identified a proline transporter (TcAAAP069) by yeasts complementation assays and overexpression in Trypanosoma cruzi epimastigotes. TcAAAP069 is mono-specific for proline but presents an unusual feature; the lack of stereospecificity, because it is competitively inhibited by the D- enantiomer. Parasites overexpressing TcAAAP069 have an increased intracellular proline concentration, 2.6-fold higher than controls, as a consequence of a higher proline transport rate. Furthermore, augmented proline concentration correlates with an improved resistance to trypanocidal drugs and also to reactive oxygen species including hydrogen peroxide and nitric oxide, emulating natural physiological situations. The IC50s for nifurtimox, benznidazole, H2O2 and NO. were 125%, 68%, 44% and 112% higher than controls, respectively. Finally, proline metabolism generates a higher concentration (48%) of ATP in TcAAAP069 parasites. Since proline participates on essential energy pathways, stress and drug resistance responses, these results provide a novel target for the development of new drugs for the treatments for Chagas' disease. PMID:24637744

  14. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    NASA Astrophysics Data System (ADS)

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Won Noh, Tae; Kalinin, Sergei V.; MacManus-Driscoll, Judith L.

    2015-10-01

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. By using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.

  15. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films.

    PubMed

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Noh, Tae Won; Kalinin, Sergei V; MacManus-Driscoll, Judith L

    2015-01-01

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. By using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness. PMID:26446866

  16. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    DOE PAGESBeta

    Yang, Sangmo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Noh, Tae Won; Kalinin, Sergei V.; MacManus-Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. Bymore » using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.« less

  17. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    SciTech Connect

    Yang, Sangmo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Noh, Tae Won; Kalinin, Sergei V.; MacManus-Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. By using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.

  18. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    PubMed Central

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Won Noh, Tae; Kalinin, Sergei V.; MacManus-Driscoll, Judith L.

    2015-01-01

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. By using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness. PMID:26446866

  19. Low temperature transport measurements on atomically smooth metallic and oxygen deficient strontium titanate

    NASA Astrophysics Data System (ADS)

    Barquist, C. S.; Kwak, I. H.; Bauer, J.; Edmonds, T.; Biswas, A.; Lee, Y.

    2014-12-01

    Atomically smooth, TiO2 terminated SrTiO3 (STO) substrates were prepared using a combination of chemical and thermal annealing treatments. The TiO2 terminated surface was obtained by etching with aqua regia solution and thermal annealing at 1000 °C for 30 min. The subsequent vacuum annealing at 830 °C for 10 min generated an atomically smooth and metallic surface of STO. In this paper, we report low temperature transport measurements down to 50 mK on these samples which clearly exhibit a metallic temperature dependence in the resistance. The samples show no sign of superconductivity down to the lowest temperatures.The Rsquare(T) data provide information on the physical origin of metallic behavior in STO, which might also be relevant to the current research interest in oxide interfaces.

  20. Convective and Diffusive O2 Transport Components of Peak Oxygen Uptake Following Long-duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Ade, Carl J.; Moore, A. D.

    2014-01-01

    Spaceflight reduces aerobic capacity and may be linked with maladaptations in the O2 transport pathway. The aim was to 1) evaluate the cardiorespiratory adaptations following 6 months aboard the International Space Station and 2) model the contributions of convective (Q (raised dot) O2) and peripheral diffusive (DO2) components of O2 transport to changes in peak O2 uptake (V (raised dot) O2PEAK). To date, 1 male astronaut (XX yrs) completed an incremental exercise test to measure V (raised dot) O2PEAK prior to and 2 days post-flight. Cardiac output (Q (raised dot) ) was measured at three submaximal work rates via carbon dioxide rebreathing. The Q (raised dot) :V (raised dot) O2 relationship was extrapolated to V (raised dot) O2PEAK to determine Q (raised dot) PEAK. Hemoglobin concentration was measured at rest via a venous blood sample. These measurements were used to model the changes in Q (raised dot) O2 and DO2 using Fick's principle of mass conservation and Law of Diffusion as established by Wagner and colleagues (Annu. Rev. Physiol 58: 21-50, 1996 and J. Appl. Physiol. 73: 1067-1076, 1992). V (raised dot) O2PEAK decreased postflight from 3.72 to 3.45 l min-1, but Q (raised dot) PEAK increased from 24.5 to 27.7 l min-1. The decrease in V (raised dot) O2PEAK post-flight was associated with a 21.2% decrease in DO2, an 18.6% decrease in O2 extraction, but a 3.4% increase in Q (raised dot) O2. These preliminary data suggest that long-duration spaceflight reduces peripheral diffusing capacity and that it largely contributes to the post-flight decrease in aerobic capacity.

  1. Limiting factors to oxygen transport on Mount Everest 30 years after: a critique of Paolo Cerretelli's contribution to the study of altitude physiology.

    PubMed

    Ferretti, Guido

    2003-10-01

    In 1976, Paolo Cerretelli published an article entitled "Limiting factors to oxygen transport on Mount Everest" in the Journal of Applied Physiology. The paper demonstrated the role of cardiovascular oxygen transport in limiting maximal oxygen consumption (VO2max). In agreement with the predominant view of VO2max limitation at that time, however, its results were taken to mean that cardiovascular oxygen transport does not limit VO2max at altitude. So it was argued that the limiting factor could be in the periphery, and muscle blood flow was proposed as a possible candidate. Despite this suggestion, the conclusion generated a series of papers on muscle structural characteristics. These experiments demonstrated a loss of muscle oxidative capacity in chronic hypoxia, and thus provided an unambiguous refutation of the then widespread hypothesis that an increased muscle oxidative capacity is needed at altitude to compensate for the lack of oxygen. This analysis is followed by a short account of Cerretelli's more recent work, with a special attention to the subject of the so-called "lactate paradox". PMID:14530980

  2. Defects, stoichiometry, and electronic transport in SrTiO3-δ epilayers: A high pressure oxygen sputter deposition study

    NASA Astrophysics Data System (ADS)

    Ambwani, P.; Xu, P.; Haugstad, G.; Jeong, J. S.; Deng, R.; Mkhoyan, K. A.; Jalan, B.; Leighton, C.

    2016-08-01

    SrTiO3 is not only of enduring interest due to its unique dielectric, structural, and lattice dynamical properties, but is also the archetypal perovskite oxide semiconductor and a foundational material in oxide heterostructures and electronics. This has naturally focused attention on growth, stoichiometry, and defects in SrTiO3, one exciting recent development being such precisely stoichiometric defect-managed thin films that electron mobilities have finally exceeded bulk crystals. This has been achieved only by molecular beam epitaxy, however (and to a somewhat lesser extent pulsed laser deposition (PLD)), and numerous open questions remain. Here, we present a study of the stoichiometry, defects, and structure in SrTiO3 synthesized by a different method, high pressure oxygen sputtering, relating the results to electronic transport. We find that this form of sputter deposition is also capable of homoepitaxy of precisely stoichiometric SrTiO3, but only provided that substrate and target preparation, temperature, pressure, and deposition rate are carefully controlled. Even under these conditions, oxygen-vacancy-doped heteroepitaxial SrTiO3 films are found to have carrier density, mobility, and conductivity significantly lower than bulk. While surface depletion plays a role, it is argued from particle-induced X-ray emission (PIXE) measurements of trace impurities in commercial sputtering targets that this is also due to deep acceptors such as Fe at 100's of parts-per-million levels. Comparisons of PIXE from SrTiO3 crystals and polycrystalline targets are shown to be of general interest, with clear implications for sputter and PLD deposition of this important material.

  3. Guidelines for genomic array analysis in acquired haematological neoplastic disorders.

    PubMed

    Schoumans, Jacqueline; Suela, Javier; Hastings, Ros; Muehlematter, Dominique; Rack, Katrina; van den Berg, Eva; Berna Beverloo, H; Stevens-Kroef, Marian

    2016-05-01

    Genetic profiling is important for disease evaluation and prediction of prognosis or responsiveness to therapy in neoplasia. Microarray technologies, including array comparative genomic hybridization and single-nucleotide polymorphism-detecting arrays, have in recent years been introduced into the diagnostic setting for specific types of haematological malignancies and solid tumours. It can be used as a complementary test or depending on the neoplasia investigated, also as a standalone test. However, comprehensive and readable presentation of frequently identified complex genomic profiles remains challenging. To assist diagnostic laboratories, standardization and minimum criteria for clinical interpretation and reporting of acquired genomic abnormalities detected through arrays in neoplastic disorders are presented. © 2016 Wiley Periodicals, Inc. PMID:26774012

  4. Cord blood transplantation in children with haematological malignancies.

    PubMed

    Bertaina, Alice; Bernardo, Maria Ester; Caniglia, Maurizio; Vinti, Luciana; Giorgiani, Giovanna; Locatelli, Franco

    2010-06-01

    Umbilical cord blood transplantation (UCBT) is largely used to treat children affected by haematological malignant disorders. In comparison to bone marrow transplantation (BMT), advantages of UCBT include lower incidence and severity of graft-versus-host disease, easier procurement and prompter availability of cord blood cells, and the possibility of using donors having HLA disparities with the recipient. The large experience accumulated so far has shown that UCBT offers to children a probability of cure at least comparable to that of patients transplanted with bone marrow cells. Since it has been demonstrated that an inverse correlation between the number of nucleated cord blood cells infused per kg recipient body weight and the risk of dying for transplantation-related causes exists, recently developed strategies aimed at increasing the number of cord blood progenitors and at favouring stem cell homing could further optimize the outcome of children with leukemia or other malignancies receiving UCBT. PMID:20837330

  5. William Hewson (1739-74): the father of haematology.

    PubMed

    Doyle, Derek

    2006-05-01

    William Hewson has been called the father of haematology. Initially working alongside the Hunter brothers in London in the mid-18th century, he advanced our knowledge of red and white cells (but mistakenly thought some red cells started as white cells and could not recognise different varieties of white corpuscles), showed that it was fibrinogen and not the cells that led to coagulation, greatly advanced our knowledge of the lymphatic system in humans, fishes and amphibians, explored the functions of the thymus and spleen and, investigated pneumothorax and surgical emphysema. His life, cut short at 35 years, was often intertwined with those of the Hunters, Alexander Monro secundus and Benjamin Franklin. This paper reviews his work, his relationships and his impact on a nascent science. PMID:16643443

  6. Haematology of wild penguins (spenisciformes) in the Falkland Islands.

    PubMed

    Hawkey, C M; Horsley, D T; Keymer, I F

    1989-07-01

    Haematological values were determined in 50 Rockhopper (Eudyptes crestatus), 19 Gentoo (Pygoscelis papua) and 12 Magellanic (Spheniscus magellanicus) penguins from various sites on the Falkland Islands. Adult Magellanic penguins had significantly lower haemoglobin (Hb) levels, packed cell volumes (PCV) and red cell counts (RBC) than adults of the other two species. Hb, PCV and RBC values were also lower in juvenile birds than in adults and lower in post-moult than in pre-moult adults. Comparison of findings in wild Rockhopper and Gentoo penguins with values obtained from captive birds showed slight but significant differences in Hb and mean cell haemoglobin concentration, and in the relative numbers of heterophils, lymphocytes, monocytes and eosinophils present. PMID:18679879

  7. Effects of erythropoietin on systemic hematocrit and oxygen transport in the splenectomized horse.

    PubMed

    McKeever, Kenneth H; McNally, Beth A; Hinchcliff, Kenneth W; Lehnhard, Robert A; Poole, David C

    2016-05-01

    To test the hypotheses that erythropoietin (rhuEPO) treatment increases systemic hematocrit, maximal O2 uptake (VO2max, by elevated perfusive and diffusive O2 conductances) and performance five female horses (4-13 years) received 15 IU/kg rhuEPO (erythropoietin) three times per week for three weeks. These horses had been splenectomized over 1 year previously to avoid confounding effects from the mobilization of splenic red blood cell reserves. Each horse performed three maximal exercise tests (one per month) on an inclined (4°) treadmill to the limit of tolerance; two control trials and one following EPO treatment. Measurements of hemoglobin concentration ([Hb] and hematocrit), plasma and blood volume, VO2, cardiac output as well as arterial and mixed venous blood gases were made at rest and during maximal exercise. EPO increased resting [Hb] by 18% from 13.3 ± 0.6 to 15.7 ± 0.8 g/dL (mean ± SD) corresponding to an increased hematocrit from 36 ± 2 to 46 ± 2% concurrent with 23 and 10% reductions in plasma and blood volume, respectively (all P<0.05). EPO elevated VO2max by 20% from 25.7 ± 1.7 to 30.9 ± 3.4 L/min (P<0.05) via a 17% increase in arterial O2 content and 18% greater arteriovenous O2 difference in the face of an unchanged cardiac output. To achieve the greater VO2max after EPO, diffusive O2 conductance increased ∼ 30% (from 580 ± 76 to 752 ± 166 mL O2/mmHg/min, P<0.05) which was substantially greater than the elevation of perfusive O2 conductance. These effects of EPO were associated with an increased exercise performance (total running time: control, 216 ± 72; EPO, 264 ± 48 s, P<0.05). We conclude that EPO substantially increases VO2max and performance in the splenectomized horse via improved perfusive and diffusive O2 transport. PMID:26853328

  8. Effect of Ionization Potential of Hole Transport Layer on Device Characteristics of Organic Light Emitting Diode with Oxygen Plasma Treated Indium Tin Oxide

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yuichi; Hamagaki, Manabu; Sakakibara, Takeshi

    2001-07-01

    We have investigated the contribution of the oxygen ions and electrons, and of the kinetic energy of these species on oxygen plasma treatment of indium tin oxide (ITO) electrode. In the case of the treatment by positive oxygen ions with kinetic energy of 50 eV, the luminance increased markedly with a lowering of the operating voltage in the organic light emitting diode (OLED). The change in the device characteristics was attributed to an effective removal of organic contaminants from the ITO surface, leading to enhanced hole injection from ITO to a hole transport layer (HTL) due to an increase in work function of the ITO@. Moreover, the highest luminance and luminous efficiency were obtained in the OLED having HTL with ionization potential of 5.4 eV@. These results have suggested that OLEDs fabricated using the oxygen plasma treated ITO can give the best device performance by the selection of an optimum HTL.

  9. GASP - THERMODYNAMIC AND TRANSPORT PROPERTIES OF HELIUM, METHANE, NEON, NITROGEN, CARBON MONOXIDE, CARBON DIOXIDE, OXYGEN, AND ARGON

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.

    1994-01-01

    A computer program, GASP, has been written to calculate the thermodynamic and transport properties of argon, carbon dioxide, carbon monoxide, fluorine, methane, neon, nitrogen, and oxygen. GASP accepts any two of pressure, temperature, or density as input. In addition, entropy and enthalpy are possible inputs. Outputs are temperature, density, pressure, entropy, enthalpy, specific heats, expansion coefficient, sonic velocity, viscosity, thermal conductivity, and surface tension. A special technique is provided to estimate the thermal conductivity near the thermodynamic critical point. GASP is a group of FORTRAN subroutines. The user typically would write a main program that invoked GASP to provide only the described outputs. Subroutines are structured so that the user may call only those subroutines needed for his particular calculations. Allowable pressures range from 0.l atmosphere to 100 to l,000 atmospheres, depending on the fluid. Similarly, allowable pressures range from the triple point of each substance to 300 degrees K to 2000 degrees K, depending on the substance. The GASP package was developed to be used with heat transfer and fluid flow applications. It is particularly useful in applications of cryogenic fluids. Some problems associated with the liquefication, storage, and gasification of liquefied natural gas and liquefied petroleum gas can also be studied using GASP. This program is written in FORTRAN IV for batch execution and is available for implementation on IBM 7000 series computers. GASP was developed in 1971.

  10. Effects of oxygen content on the structural and transport properties in epitaxial Nd0.7Sr0.3MnO thin films

    NASA Astrophysics Data System (ADS)

    Meng, Ying; He, Wenlan; Li, Aixia; Li, Guang; Jin, Shaowei

    2012-07-01

    Epitaxial Nd0.7Sr0.3MnO3-x (NSMO) thin films, 120 nm thickness, were grown coherently on the (0 0 1) (LaAlO3)0.3 (Sr2AlTaO6)0.7 (LSAT) substrates by using pulsed-laser deposition (PLD). Effects of oxygen contents controlled by post-annealing in vacuum on the structural and transport properties of the NSMO films were carefully studied by x-ray reciprocal space maps (RSMs) and resistivity measurements. It is clearly shown that both the out-of-plane lattice parameters of the films and the transition temperatures Tp (peak resistance) can simultaneously change as the oxygen contents, the in-plane lattice coherency is maintained consistently with that of the LSAT substrate at the same time. The larger altered transport properties are chiefly ascribed to the increase of Mn3+ ions and the distortion of MnO6 octahedra in films. The oxygen compositions are deduced from the out-of-plane lattice parameters of coherency epitaxy NSMO films. The Kröger-Vink notation was used for explaining the correlation of oxygen vacancy and transport properties.

  11. Low shear red cell oxygen transport effectiveness is adversely affected by transfusion and further worsened by deoxygenation in sickle cell disease patients on chronic transfusion therapy

    PubMed Central

    Detterich, Jon; Alexy, Tamas; Rabai, Miklos; Dongelyan, Ani; Coates, Thomas; Wood, John; Meiselman, Herbert

    2012-01-01

    BACKGROUND Simple chronic transfusion therapy (CTT) is a mainstay for stroke prophylaxis in sickle cell anemia, but its effects on hemodynamics are poorly characterized. Transfusion improves oxygen carrying capacity, reducing demands for high cardiac output. While transfusion decreases factors associated with vaso-occlusion, including percent HbS, reticulocyte count and circulating cell-free hemoglobin, it increases blood viscosity, which reduces microvascular flow. The hematocrit to viscosity ratio (HVR) is an index of red cell oxygen transport effectiveness that varies with shear stress and balances the benefits of improved oxygen capacity to viscosity-mediated impairment of microvascular flow. We hypothesized that transfusion would improve HVR at high shear despite increased blood viscosity, but would decrease HVR at low shear. STUDY DESIGN AND METHODS To test this hypothesis, we examined oxygenated and deoxygenated blood samples from 15 sickle cell patients on CTT immediately pre-transfusion and again 12–120 hours post-transfusion. RESULTS Comparable changes in hemoglobin, hematocrit, reticulocyte count and hemoglobin S with transfusion were observed in all subjects. Viscosity, hematocrit and high-shear HVR increased with transfusion while low shear HVR decreased significantly. CONCLUSION Decreased low-shear HVR suggests impaired oxygen transport to low-flow regions and may explain why some complications of sickle cell anemia are ameliorated by chronic transfusion therapy and others may be made worse. PMID:22882132

  12. Physical complications in anorexia nervosa. Haematological and neuromuscular changes in 12 patients.

    PubMed

    Alloway, R; Shur, E; Obrecht, R; Russell, G F

    1988-07-01

    Of twelve patients consecutively admitted to the Maudsley Hospital Eating Disorders Unit, four had neuromuscular abnormality, eight haematological abnormality, and four no abnormality. All those having neuromuscular signs had concomitant haematological dysfunction. Vomiting, and food restriction with vegetarianism, appeared more likely to lead to complications than either food restriction alone or laxative abuse. The physical status of severely underweight patients admitted for refeeding needs to be carefully monitored. PMID:3224253

  13. Single- and Bayesian Multi-Marker Genome-Wide Association for Haematological Parameters in Pigs

    PubMed Central

    Ponsuksili, Siriluck; Reyer, Henry; Trakooljul, Nares; Murani, Eduard

    2016-01-01

    Haematological traits are important traits that show associations with immune and metabolic status, as well as diseases in humans and animals. Mapping genome regions that affect the blood cell traits can contribute to the identification of genomic features useable as biomarkers for immune, disease and metabolic status. A genome-wide association study (GWAS) was conducted using PorcineSNP60 BeadChips. Single-marker and Bayesian multi-marker approaches were integrated to identify genomic regions and corresponding genes overlapping for both methods. GWAS was performed for haematological traits of 591 German Landrace pig. Heritability estimates for haematological traits were medium to high. In total 252 single SNPs associated with 12 haematological traits were identified (NegLog10 of p-value > 5). The Bayesian multi-marker approach revealed 102 QTL regions across the genome, indicated by 1-Mb windows with contribution to additive genetic variance above 0.5%. The integration of both methods resulted in 24 overlapping QTL regions. This study identified overlapping QTL regions from single- and multi-marker approaches for haematological traits. Identifying candidate genes that affect blood cell traits provides the first step towards the understanding of the molecular basis of haematological phenotypes. PMID:27434032

  14. [The state of acid-alkaline balance and oxygen-transport function of blood in patients with acute carotid ischemic stroke].

    PubMed

    Zhdanova, S G; Aliev, E S; Kamchatnov, P R; Mikhaĭlova, N A

    2012-01-01

    The gas composition, acid-alkaline state of arterial and venous blood and oxygen-transport function in carotid ischemic stroke was studied in 97 patients admitted to a hospital in the first 24h after stroke. Measurements were made at admission and after 5-7 days and 21-23 days. The relative hyperoxia, which reached maximal values to the first day, was found in patients in the acute stage of ischemic stroke. The increase in partial pressure of CO2 (pCO2) and relative acidosis seen to 5-7 days represent the compensatory reaction and lead to the increase in affinity of hemoglobin to oxygen thus improving the tissue oxygenation. We found the inverse correlations between the parameters of oxygen delivery (OD) and oxygen consumption (OC) in the first day and the severity of neurological deficit assessed with the NIHSS in the 21-23 days (r = -0.42; p < 0.01 and r = -0.55; p < 0.01 for OD and OC, respectively), i.e., the decrease in oxygen delivery and consumption corresponded to the greater severity of the stroke course. PMID:23390649

  15. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; T. Nithyanantham

    2006-06-30

    A non-agglomerated and nanocrystalline-sized powder was successfully produced using ethylene glycol nitrate methods. The LSFT powder prepared using this method exhibits well dispersed and nano-sized particles about 100-200 nm. The density of LSFT sintered at 1300 C was about 90% of the theoretical density at which is 100 C less than that of the previous LSFT which was sintered at 1400 C. The sample sintered at 1400 C exhibited the evidence of a liquid phase at the grain boundaries and 2nd phase formation which probably caused low mechanical stability. The electrical conductivity and Seebeck coefficient were measured as a function of temperature. The LSFT-CGO specimens were cut from the as sintered bars and used for the evaluation of Mechanical Properties after polishing. The effect of strain rate on the flexural strength of the LSFT-CGO test specimens was studied. Three strain rates 6, 60 and 600 {micro}m/ min were chosen for this study. It is observed from the results that with increasing cross head speed the membrane takes higher loads to fail. A reduction in the strength of the membrane was observed at 1000 C in N{sub 2}. Two different routes were investigated to synthesis GDC using either formate or carbonate precursors. The precursor and CGO particle morphologies were examined by scanning electron microscopy. The thermal decomposition behaviors of Ce(Gd)(HCOO){sub 3} and Ce(Gd)(CO{sub 3})(OH) were determined by thermogravimetric analysis (TGA) at a rate of 3 C/min in air. The X-ray powder diffraction patterns of the precursor and CGO were collected and nitrogen adsorption isotherms were measured. Conductivity measurements were made by AC impedance spectroscopy on sintered disks in air using platinum electrodes.

  16. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2001-05-01

    The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

  17. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-05-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped Ti-substituted perovskites, La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Ti{sub x}O{sub 3}, with 0 {le} x {le} 0.20, were investigated by neutron diffraction, magnetization, electric resistivity, and magnetoresistance (MR) measurements. All samples show a rhombohedral structure (space group R3C) from 10 K to room temperature. At room temperature, the cell parameters a, c and the unit cell volume increase with increasing Ti content. However, at 10 K, the cell parameter a has a maximum value for x = 0.10, and decreases for x > 0.10, while the unit cell volume remains nearly constant for x > 0.10. The average (Mn,Ti)-O bond length increases up to x = 0.15, and the (Mn,Ti)-O-(Mn,Ti) bond angle decreases with increasing Ti content to its minimum value at x = 0.15 at room temperature. Below the Curie temperature TC, the resistance exhibits metallic behavior for the x {le} 0.05 samples. A metal (semiconductor) to insulator transition is observed for the x {ge} 0.10 samples. A peak in resistivity appears below TC for all samples, and shifts to a lower temperature as x increases. The substitution of Mn by Ti decreases the 2p-3d hybridization between O and Mn ions, reduces the bandwidth W, and increases the electron-phonon coupling. Therefore, the TC shifts to a lower temperature and the resistivity increases with increasing Ti content. A field-induced shift of the resistivity maximum occurs at x {le} 0.10 compounds. The maximum MR effect is about 70% for La{sub 0.7}Sr{sub 0.3}Mn{sub 0.8}Ti{sub 0.2}O{sub 3}. The separation of TC and the resistivity maximum temperature T{sub {rho},max} enhances the MR effect in these compounds due to the weak coupling between the magnetic ordering and the resistivity as compared with La{sub 0.7}Sr{sub 0.3}MnO{sub 3}. The bulk densities of the membranes were determined using the Archimedes method. The bulk density was 5.029 and 5.57 g/cc for LSFT and dual phase membranes, respectively. The microstructure of the dual phase membrane was analyzed using SEM. It is evident from the micrograph that the microstructure is composed of dual phases. The dense circular regions are enclosed by the less dense, continuous phase which accommodates most of the pores. The pores are normally aggregated and found clustered along the dense regions where as the dense regions do not have pores. Upon closer observation of the micrograph it is revealed that the dense region has a clear circular cleavage or crack as their boundary. The circular cleavage clearly encompasses a dense region and which consists of no pore or any flaw that is visible. The size distribution of the dense, discontinuous regions is varying from 5 to 20 {micro}m with a D{sub 50} of 15 {micro}m. The grain size distribution was estimated from the micrographs using image analysis and a unimodal distribution of grains was observed with an average grain size of 1.99 {micro}m. The chemical compositions of the membranes were analyzed using EDS analysis and no other impurities were observed. The XRD analysis was carried out for the membranes and the phase purity was confirmed. The fracture toughness of LSFT membranes at room temperature has to be calculated using the Vickers indentation method. An electrochemical cell has been designed and built for measurements of the ionic conductivity by the use of blocking electrodes. Preliminary measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Modifications to the apparatus to improve the data quality have been completed. Electron microscopy studies of the origin of the slow kinetics on reduction of ferrites have been initiated. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradient

  18. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendfra Nagabhushana

    2001-07-01

    The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

  19. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-07-01

    This is the fourth quarterly report on a new study to develop a ceramic membrane/metal joint. The first experiments using the La-Sr-Fe-O ceramic are reported. Some of the analysis performed on the samples obtained are commented upon. A set of experiments to characterize the mechanical strength and thermal fatigue properties of the joints has been designed and begun. Finite element models of joints used to model residual stresses are described.

  20. Oxygen Transport Ceramic Membranes

    SciTech Connect

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2006-05-01

    In this quarter a systematic analysis on the decomposition behavior of the OTM membranes at air and nitrogen were initiated to understand the structural and stoichiometric changes associated with elevated temperatures. Evaluation of the flexural strengths using 4-point bend test was also started for the dual phase membranes. Initial results on the synthesis of dual phase composite materials have been obtained. The measurements have focused on the compatibility of mixed conductors with the pure ionic conductors yttria stabilized zirconia (YSZ) and gadolinium doped ceria (GDC). The initial results obtained for three different mixed conductors suggest that (GDC) is the better choice. A new membrane permeation system has been designed and tested and sintering studies of biphasic systems are in progress.

  1. Dual-Phase Oxygen Transport Membranes for Stable Operation in Environments Containing Carbon Dioxide and Sulfur Dioxide.

    PubMed

    Garcia-Fayos, Julio; Balaguer, María; Serra, José M

    2015-12-21

    Dual-phase membranes are appealing candidates for oxygen transport membranes owing to their unique combination of ambipolar electron-ion transport and endurance. However, O2 separation in industrial environments demands very high stability and effectiveness in the presence of CO2- and SO2-bearing process gases. Here, the composition of dual-phase membranes based on NiFe2O4-Ce(0.8) Tb(0.2)O(2-δ) (NFO-CTO) was optimized and the effective performance of catalytically-activated membranes was assessed in presence of CO2 and SO2. Further insight into the limiting mechanisms in the permeation was gained through electrical conductivity studies, permeation testing in several conditions and impedance spectroscopy analysis. The dual-phase membranes were prepared by one-pot sol-gel method and their permeability increases with increasing fluorite content. An O2 flux of 0.25 (ml min(-1)  cm(-2)) mm at 1000 °C was obtained for a thick self-standing membrane with 40:60 NFO/CTO composition. An in-depth study mimicking typical harsh conditions encountered in oxyfuel flue gases was performed on a 50:50 NFO/CTO membrane. CO2 content as well as SO2 presence in the sweep gas stream were evaluated in terms of O2 permeation. O2 fluxes of 0.13 and 0.09 mL min(-1)  cm(-2) at 850 °C were obtained for a 0.59 mm thick membrane under CO2 and 250 ppm SO2 in CO2 sweep conditions, respectively. Extended periods at work under CO2- and SO2-containing atmospheres revealed good permeation stability over time. Additionally, XRD, backscattered electrons detector (BSD)-SEM, and energy-dispersive X-ray spectroscopy (EDS) analysis of the spent membrane confirmed material stability upon prolonged exposure to SO2. PMID:26586419

  2. Oxygen evolution from single- and multiple-turnover light pulses: temporal kinetics of electron transport through PSII in sunflower leaves.

    PubMed

    Oja, Vello; Eichelmann, Hillar; Laisk, Agu

    2011-12-01

    Oxygen evolution per single-turnover flash (STF) or multiple-turnover pulse (MTP) was measured with a zirconium O(2) analyzer from sunflower leaves at 22 °C. STF were generated by Xe arc lamp, MTP by red LED light of up to 18000 μmol quanta m(-2) s(-1). Ambient O(2) concentration was 10-30 ppm, STF and MTP were superimposed on far-red background light in order to oxidize plastoquinone (PQ) and randomize S-states. Electron (e(-)) flow was calculated as 4 times O(2) evolution. Q (A) → Q (B) electron transport was investigated firing double STF with a delay of 0 to 2 ms between the two. Total O(2) evolution per two flashes equaled to that from a single flash when the delay was zero and doubled when the delay exceeded 2 ms. This trend was fitted with two exponentials with time constants of 0.25 and 0.95 ms, equal amplitudes. Illumination with MTP of increasing length resulted in increasing O(2) evolution per pulse, which was differentiated with an aim to find the time course of O(2) evolution with sub-millisecond resolution. At the highest pulse intensity of 2.9 photons ms(-1) per PSII, 3 e(-) initially accumulated inside PSII and the catalytic rate of PQ reduction was determined from the throughput rate of the fourth and fifth e(-). A light response curve for the reduction of completely oxidized PQ was a rectangular hyperbola with the initial slope of 1.2 PSII quanta per e(-) and V (m) of 0.6 e(-) ms(-1) per PSII. When PQ was gradually reduced during longer MTP, V (m) decreased proportionally with the fraction of oxidized PQ. It is suggested that the linear kinetics with respect to PQ are apparent, caused by strong product inhibition due to about equal binding constants of PQ and PQH(2) to the Q (B) site. The strong product inhibition is an appropriate mechanism for down-regulation of PSII electron transport in accordance with rate of PQH(2) oxidation by cytochrome b(6)f. PMID:22038184

  3. Why Are High-Altitude Natives So Strong at Altitude? Maximal Oxygen Transport to the Muscle Cell in Altitude Natives.

    PubMed

    Lundby, Carsten; Calbet, Jose A L

    2016-01-01

    In hypoxia aerobic exercise performance of high-altitude natives is suggested to be superior to that of lowlanders; i.e., for a given altitude natives are reported to have higher maximal oxygen uptake (VO2max). The likely basis for this is a higher pulmonary diffusion capacity, which in turn ensures higher arterial O2 saturation (SaO2) and therefore also potentially a higher delivery of O2 to the exercising muscles. This review focuses on O2 transport in high-altitude Aymara. We have quantified femoral artery O2 delivery, arterial O2 extraction and calculated leg VO2 in Aymara, and compared their values with that of acclimatizing Danish lowlanders. All subjects were studied at 4100 m. At maximal exercise SaO2 dropped tremendously in the lowlanders, but did not change in the Aymara. Therefore arterial O2 content was also higher in the Aymara. At maximal exercise however, fractional O2 extraction was lower in the Aymara, and the a-vO2 difference was similar in both populations. The lower extraction levels in the Aymara were associated with lower muscle O2 conductance (a measure of muscle diffusion capacity). At any given submaximal exercise intensity, leg VO2 was always of similar magnitude in both groups, but at maximal exercise the lowlanders had higher leg blood flow, and hence also higher maximum leg VO2. With the induction of acute normoxia fractional arterial O2 extraction fell in the highlanders, but remained unchanged in the lowlanders. Hence high-altitude natives seem to be more diffusion limited at the muscle level as compared to lowlanders. In conclusion Aymara preserve very high SaO2 during hypoxic exercise (likely due to a higher lung diffusion capacity), but the effect on VO2max is reduced by a lower ability to extract O2 at the muscle level. PMID:27343089

  4. Assessment of suspended-sediment transport, bedload, and dissolved oxygen during a short-term drawdown of Fall Creek Lake, Oregon, winter 2012-13

    USGS Publications Warehouse

    Schenk, Liam N.; Bragg, Heather M.

    2014-01-01

    The drawdown of Fall Creek Lake resulted in the net transport of approximately 50,300 tons of sediment from the lake during a 6-day drawdown operation, based on computed daily values of suspended-sediment load downstream of Fall Creek Dam and the two main tributaries to Fall Creek Lake. A suspended-sediment budget calculated for 72 days of the study period indicates that as a result of drawdown operations, there was approximately 16,300 tons of sediment deposition within the reaches of Fall Creek and the Middle Fork Willamette River between Fall Creek Dam and the streamgage on the Middle Fork Willamette River at Jasper, Oregon. Bedload samples collected at the station downstream of Fall Creek Dam during the drawdown were primarily composed of medium to fine sands and accounted for an average of 11 percent of the total instantaneous sediment load (also termed sediment discharge) during sample collection. Monitoring of dissolved oxygen at the station downstream of Fall Creek Dam showed an initial decrease in dissolved oxygen concurrent with the sediment release over the span of 5 hours, though the extent of dissolved oxygen depletion is unknown because of extreme and rapid fouling of the probe by the large amount of sediment in transport. Dissolved oxygen returned to background levels downstream of Fall Creek Dam on December 18, 2012, approximately 1 day after the end of the drawdown operation.

  5. Use of tunnelled catheters in haematological malignancy patients with neutropenia.

    PubMed

    Sariosmanoglu, N; Uğurlu, B; Turgut, N H; Demirkan, F; Ozsan, H; Ergor, G; Gulay, Z; Hazan, E; Oto, O

    2008-01-01

    This prospective study analysed 83 patients (age 45 +/- 17 years) with haematological neoplasms, implanted with 93 tunnelled catheters, who were neutropenic or developed neutropenia during treatment. Catheters were implanted in the right (n = 82) or left (n = 11) jugular vein by the same surgical team using the same technique. They remained in place for 124 +/- 88 days: 29% were removed due to infection; 18% due to treatment termination and 2% due to mechanical problems. Seventeen patients died with catheters in place. At 30, 60, 90, 120 and 200 days mean catheter duration rates were 82%, 75%, 65%, 60% and 35%, respectively, and freedom from catheter removal due to infection was 92%, 88%, 80%, 77% and 67%, respectively. Patient diagnosis and history of previous catheter infection did not increase catheter infection risk, but patients undergoing stem cell transplantation had an increased infection risk. Tunnelled catheters can be used in high-risk patients with neutropenia. Systemic infections can be managed in most patients without catheter removal. PMID:18831907

  6. Curriculum Design of a Flipped Classroom to Enhance Haematology Learning

    NASA Astrophysics Data System (ADS)

    Porcaro, Pauline A.; Jackson, Denise E.; McLaughlin, Patricia M.; O'Malley, Cindy J.

    2016-06-01

    A common trend in higher education is the "flipped" classroom, which facilitates active learning during class. The flipped approach to teaching was instituted in a haematology `major' class and the students' attitudes and preferences for the teaching materials were surveyed. The curriculum design was explicit and involved four major components (1) the preparation of the students; (2) the weekly pre-class work; (3) the in-class active learning strategies and (4) closing the learning loop using formative quizzes. Each of these components is discussed in detail and was informed by sound pedagogical strategies. Several different sources of information and several freely available software tools to engage the students are discussed. Two iterations are reported here, with improved pass rate for the final examination from 47 to 48 % in the traditional class to 56-65 % in the flipped classroom approach. The majority of students (93 and 89 %) came to the class prepared, after viewing the screencasts and engaged fully with the activities within the face-to-face time. The students perceived that solving case studies (93 %) was the most beneficial activity for their learning and this was closely followed by the production of essay plans (71 %). The majority of students recommended that this approach be repeated the following year (69 and 75 %).

  7. A cluster of Candida krusei infections in a haematological unit

    PubMed Central

    Hautala, Timo; Ikäheimo, Irma; Husu, Heidi; Säily, Marjaana; Siitonen, Timo; Koistinen, Pirjo; Vuopio-Varkila, Jaana; Koskela, Markku; Kujala, Pekka

    2007-01-01

    Background Candida krusei infections are associated with high mortality. In order to explore ways to prevent these infections, we investigated potential routes for nosocomial spread and possible clonality of C. krusei in a haematological unit which had experienced an unusually high incidence of cases. Methods We searched for C. krusei contamination of the hospital environment and determined the level of colonization in patients and health care workers. We also analyzed the possible association between exposure to prophylactic antifungals or chemotherapeutic agents and occurrence of C. krusei. The C. krusei isolates found were genotyped by pulsed-field electrophoresis method in order to determine possible relatedness of the cases. Results Twelve patients with invasive C. krusei infection and ten patients with potentially significant infection or mucosal colonization were documented within nine months. We were unable to identify any exogenic source of infection or colonization. Genetic analysis of the isolates showed little evidence of clonal transmission of C. krusei strains between the patients. Instead, each patient was colonized or infected by several different closely related genotypes. No association between medications and occurrence of C. krusei was found. Conclusion Little evidence of nosocomial spread of a single C. krusei clone was found. The outbreak may have been controlled by cessation of prophylactic antifungals and by intensifying infection control measures, e.g. hand hygiene and cohorting of the patients, although no clear association with these factors was demonstrated. PMID:17711592

  8. Haematological manifestations of human immune deficiency virus infection.

    PubMed

    Vishnu, Prakash; Aboulafia, David M

    2015-12-01

    Early in the human immunodeficiency virus (HIV) epidemic, infected patients presented to medical attention with striking abnormalities in each of the major blood cell lineages. The reasons for these derangements remain complex and multifactorial. HIV infects multipotent haematopoietic progenitor cells and establish latent cellular reservoirs, disturbs the bone marrow microenvironment and also causes immune dysregulation. These events lead to cytokine imbalances and disruption of other factors required for normal haematopoiesis. Activation of the reticulo-endothelial system can also result in increased blood cell destruction. The deleterious effects of medications, including first and second generation anti-retroviral agents, on haematopoiesis were well documented in the early years of HIV care; in the current era of HIV-care, the advent of newer and less toxic anti-retroviral drugs have had a more beneficial impact on haematopoiesis. Due to impaired regulation of the immune system and potential side effects of one or more anti-retroviral agents, there is also an increase in coagulation abnormalities such as thromboembolism, and less frequently, acquired disorders of coagulation including thrombotic thrombocytopenic purpura, immune thrombocytopenic purpura and acquired inhibitors of coagulation. In this article we review the epidemiology and aetiology of select non-oncological haematological disorders commonly seen in people living with HIV-acquired immune deficiency syndrome. PMID:26452169

  9. Haematological characteristics associated with parasitism in bream, Abramis brama orientalis.

    PubMed

    Hayatbakhsh, Mohammad Reza; Khara, Hossein; Movahed, Rashideh; Sayadborani, Mohammad; Rohi, Javad Daghigh; Ahmadnezhad, Mohadesseh; Rahbar, Mina; Rad, Amir Sajedi

    2014-12-01

    A parasitological investigation was done on 175 specimens. Infections of A. brama orientalis were analyzed according to the age and sex. The fish also were examined for evaluation changes of haematological parameters in relation to parasitic infection. Four parasites were found, including-Caryophyllaeus laticeps and Ligula intestinalis (Cestoda), Diplostomum spathaceum (Platyhelminthes) and Trichodina sp. (Ciliophora). Among identified parasites maximum prevalence and mean intensity were related to Ligula intestinalis and Caryophyllaeus laticeps respectively. The values of prevalence and mean intensity showed significant differences among ages. Our results revealed prevalence, mean intensity and abundance had not significant difference between males and females. Parasite infection provoked reduction (P < 0.05) in haematocrit, mean cell volume and lymphocyte. On the other hand, significant increase (P < 0.05) in white blood cell (WBC), mean cell haemoglobin concentration and neutrophil in blood of infected fish was observed. Significant differences were detected for the WBC, lymphocyte and neutrophil (infected versus uninfected by Trichodina sp., Diplostomum spathaceum and Caryophyllaeus laticeps). In addition to WBC and lymphocytes, significant change was observed for the haemoglobin (Hb) (infected versus uninfected by Ligula intestinalis). PMID:25320488

  10. Current status of chimeric antigen receptor therapy for haematological malignancies.

    PubMed

    Maude, Shannon; Barrett, David M

    2016-01-01

    The field of adoptive cell transfer includes chimeric antigen receptor (CAR) engineered T cells, constructs that emerged from basic research into principles of immunology and have transformed into clinically effective therapies for haematological malignancies. T cells engineered to express these artificial receptors hold great promise, but also carry significant risk. While permanent genetic modification of mature T cells appears safe, modulating their in vivo function is difficult, partly because the robust response can trigger other arms of the immune system. Suicide systems and toxicity management with cytokine blockade or signal transduction modulators have emerged as a new frontier in this field, a far cry from early problems getting CAR T cells to work at all. Currently, clinical trials in patients with relapsed or refractory B cell malignancies treated with CD19-specific CAR T cells have induced durable remissions in adults and children. Results from these trials indicate that more work needs to be done to understand biomarkers of efficacy, the role of T cell persistence and how to integrate this care into standard practice. Cell therapy will not be a 'one size fits all' class of medicine, and here we will discuss the development of this therapy and important questions for its future. PMID:26560054

  11. Mathematical model of water transport in Bacon and alkaline matrix-type hydrogen-oxygen fuel cells

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.; Easter, R. W.

    1972-01-01

    Based on general mass continuity and diffusive transport equations, a mathematical model was developed that simulates the transport of water in Bacon and alkaline-matrix fuel cells. The derived model was validated by using it to analytically reproduce various Bacon and matrix-cell experimental water transport transients.

  12. Clinical, haematological and biochemical responses of sheep undergoing autologous blood transfusion

    PubMed Central

    2012-01-01

    Background This study aimed to evaluate the clinical, haematological and biochemical responses to autologous blood transfusion and the feasibility of this practice in sheep. Thus, we used eight male, 8 months old sheep, weighing on average 30 kg, from which 15 mL/kg of whole blood was collected and stored in CPDA-1 bags. Blood samples were refrigerated for 8 days and subsequently re-infused. The clinical, haematological and biochemical parameters were evaluated before blood collection and reinfusion, after 10 minutes of collection and reinfusion, after 3, 6, 12, 24, 48, 96 and 192 hours after collection and reinfusion. Results With respect to clinical parameters, we observed a decrease in heart rate after 24, 48 and 196 hours from reinfusion compared to basal values (p < 0.05). Haematological variables including globular volume and erythrocyte counts showed a significant decrease (p < 0.01) at all time points after collection and increased (p < 0.01) at all time points after reinfusion. There was a significant increase in total protein and calcium at all time points after reinfusion (p < 0.05). Conclusion Autologous transfusion in sheep slightly altered the physiological, biochemical and haematological responses of sheep, indicating that the technique proposed is safe and can be applied in the clinical practice of this species. The 8 d period was not sufficient for complete recovery of the haematological parameters after blood collection. PMID:22607611

  13. Pneumocystis jirovecii pneumonia: still a concern in patients with haematological malignancies and stem cell transplant recipients.

    PubMed

    Cordonnier, Catherine; Cesaro, Simone; Maschmeyer, Georg; Einsele, Hermann; Donnelly, J Peter; Alanio, Alexandre; Hauser, Philippe M; Lagrou, Katrien; Melchers, Willem J G; Helweg-Larsen, Jannik; Matos, Olga; Bretagne, Stéphane; Maertens, Johan

    2016-09-01

    Pneumocystis jirovecii can cause life-threatening pneumonia following treatment for haematological malignancies or after HSCT. The mortality rate of P. jirovecii pneumonia (PCP) in these patients is 30%-60%, especially after HSCT. The clinical presentation of PCP in haematology differs from that associated with HIV infection, with the disease being acute and more often severe, having a lower fungal burden and being more frequently linked to treatment with corticosteroids. Most cases occur in patients not receiving adequate prophylaxis. The development of new therapies, including targeted treatments and monoclonal antibodies in various haematological diseases, justifies constant vigilance in order to identify new at-risk populations and give prophylaxis accordingly. The fifth and sixth European Conferences on Infections in Leukaemia (ECIL-5 and ECIL-6) aimed to review risk factors for PCP in haematology patients and to establish evidence-based recommendations for PCP diagnosis, prophylaxis and treatment. This article focuses on the magnitude of the problem, the main differences in clinical presentation between haematology patients and other immunocompromised populations, especially HIV-infected patients, and the main risk factors. PMID:27550990

  14. Biochemical and haematological profile of pheasant hens during the laying period.

    PubMed

    Schumann, J; Bedanova, I; Voslarova, E; Hrabcakova, P; Chloupek, J; Pistekova, V

    2014-01-01

    The present paper provides new experimental data on the biochemical and haematological profile of blood in pheasant hens, and points out the changes in both biochemical and haematological parameters that occur during the laying period. Significant effects of egg laying on both the biochemical and the haematological blood parameters of pheasant hens were found. Biochemical analyses revealed a significant increase in the metabolites cholesterol, uric acid, lactate, the enzyme aspartate aminotransferase (AST) and the minerals calcium and phosphorous, as well as a significant decrease in total protein, albumin and glucose in the course of the laying period. Haematological analyses revealed a significant increase in the count of leukocytes, lymphocytes, eosinophils, basophils and monocytes due to egg laying. In addition, the erythrocyte count and haemoglobin content significantly decreased in the middle of the laying period and then rebounded at the end of the laying period. The haematocrit content gradually decreased till the end of the laying period. All together, the results of this study underline the impact of the reproduction status of pheasant hens on basic blood parameters. The biochemical and haematological values presented in this study may be of help in assessing disease conditions in laying pheasant hens. PMID:24724469

  15. Electric transport coefficients in highly epitaxial LaBaCo2O5 + δ films with "p-to-n" transition induced by oxygen deficiency

    NASA Astrophysics Data System (ADS)

    Shaibo, J.; Zhang, Q. Y.; Wang, Y. Q.; Hu, H. C.; Li, X. N.; Pan, L. J.

    2016-08-01

    Electric transport coefficients such as carrier type, density, and mobility are the important physical parameters in designing functional devices. In this work, we report the study on the electric transport coefficients of the highly epitaxial LaBaCo2O5 + δ (LBCO) films, which were discussed as a function of electric conductivity for the first time and compared with the results calculated by the theory for mixed conduction. The mobility in the LBCO films was determined to be ˜0.85 and ˜40 cm2/V s for holes and electrons, respectively, and the density of p-type carriers strongly depends on the oxygen deficiency. Solid evidence is presented to demonstrate that the oxygen deficiency cannot make LBCO materials changed from p- to n-type. The n-type conduction observed in experiment is a counterfeit phenomenon caused by the deficiency in Hall measurement, rather than a realistic transition induced by oxygen deficiency. In addition, the temperature-dependent conductivity was discussed using the differential coefficients, which might be useful in the study of the samples with magnetic transition.

  16. The prevention and management of infections due to multidrug resistant organisms in haematology patients.

    PubMed

    Trubiano, Jason A; Worth, Leon J; Thursky, Karin A; Slavin, Monica A

    2015-02-01

    Infections due to resistant and multidrug resistant (MDR) organisms in haematology patients and haematopoietic stem cell transplant recipients are an increasingly complex problem of global concern. We outline the burden of illness and epidemiology of resistant organisms such as gram-negative pathogens, vancomycin-resistant Enterococcus faecium (VRE), and Clostridium difficile in haematology cohorts. Intervention strategies aimed at reducing the impact of these organisms are reviewed: infection prevention programmes, screening and fluoroquinolone prophylaxis. The role of newer therapies (e.g. linezolid, daptomycin and tigecycline) for treatment of resistant and MDR organisms in haematology populations is evaluated, in addition to the mobilization of older agents (e.g. colistin, pristinamycin and fosfomycin) and the potential benefit of combination regimens. PMID:24341410

  17. Distillery effluent induced alterations in the haematological profile of fingerlings of Colisa fasciatus.

    PubMed

    Shukla, Anuradha; Shukla, J P

    2013-09-01

    Present study deals with the impact of Gorakhpur distillery effluent at various concentration levels (5, 10 and 20%) on the blood profile of fingerling of, Colisa fosciotus after 30 days of exposure. Observations revealed that 5% of effluent concentration produced no significant alterations in various haematological parameters except for clotting time and immature erythrocytes. However, 10% of effluent concentration brought significant alterations in hematocrit as well as clotting time and 20% of effluent concentration produced highly significant (P<0.001) alteration in most of the haematological parameters except for hemoglobin percentage. PMID:24558806

  18. Resuscitation with Na+/H+ exchanger inhibitor in traumatic haemorrhagic shock: cardiopulmonary performance, oxygen transport and tissue inflammation.

    PubMed

    Wu, Dongmei; Qi, Jiansong; Dai, Hui; Doods, Henri; Abraham, William M

    2010-03-01

    1. The aim of the present study was to examine the effects of inhibition of the Na(+)/H(+) exchanger (NHE-1) on cardiopulmonary performance, oxygen carrying capacity and tissue inflammation in a pig model of traumatic haemorrhage-resuscitation. 2. In 12 instrumented anaesthetized pigs, traumatic haemorrhage was modelled by producing tibia fractures, followed by haemorrhage of 25 mL/kg for 20 min, and then a 4 mm hepatic arterial tear with surgical repair after 20 min. Animals then underwent low-volume fluid resuscitation with either Hextend (vehicle; n = 6; Hospira, Lake Forest, IL, USA) or 3 mg/kg BIIB513 (an NHE-1 inhibitor) + Hextend (n = 6). The experiment was terminated 6 h after the beginning of resuscitation. 3. Compared with vehicle-treated controls, the addition of NHE-1 inhibition with BIIB513 significantly improved the left ventricle stroke work index and attenuated increases in pulmonary arterial pressure and pulmonary vascular resistance. Furthermore, BIIB513 treatment significantly increased the oxygenated haemoglobin ratio, blood oxygen content and mixed venous blood oxygen saturation and improved blood oxygen delivery. In addition, BIIB513 treatment reduced lung tissue levels of interleukin-6 by 80%, tumour necrosis factor-alpha by 37% and myeloperoxidase activity by 38%. Nuclear factor-kappaB DNA binding activity in the lung was also slightly and significantly attenuated following BIIB513 treatment. 4. In conclusion, the present study shows that NHE-1 inhibition facilitates the response to fluid resuscitation after traumatic haemorrhage by improving cardiac function, pulmonary vascular function and oxygen carrying capacity, which results in reduced tissue inflammatory injury. PMID:19769605

  19. Transport and Distribution of Hydroxyl Radicals and Oxygen Atoms from H2O Photodissociation in the Inner Coma of Comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Lai, Ian-Lin; Su, Cheng-Chin; Ip, Wing-Huen; Wei, Chen-En; Wu, Jong-Shinn; Lo, Ming-Chung; Liao, Ying; Thomas, Nicolas

    2016-03-01

    With a combination of the Direct Simulation Monte Carlo (DSMC) calculation and test particle computation, the ballistic transport process of the hydroxyl radicals and oxygen atoms produced by photodissociation of water molecules in the coma of comet 67P/Churyumov-Gerasimenko is modelled. We discuss the key elements and essential features of such simulations which results can be compared with the remote-sensing and in situ measurements of cometary gas coma from the Rosetta mission at different orbital phases of this comet.

  20. Structural, optical and transport properties of 100 MeV oxygen ion irradiated V{sub 2}O{sub 5} thin film

    SciTech Connect

    Kovendhan, M.; Joseph, D. Paul; Manimuthu, P.; Singh, J. P.; Asokan, K.; Venkateswaran, C.; Mohan, R.

    2012-06-05

    Thin films of V{sub 2}O{sub 5} were spray deposited at 450 deg. C on ITO coated glass substrates. The film with a thickness of 217 nm was irradiated with 100 MeV oxygen ion beam at a fluence of 5 x 10{sup 12} ions/cm{sup 2}. Upon irradiation, the optical transparency of the film decreased from 90% to 40% and the band gaps estimated using Tauc relation showed red shift. Transport parameters were also measured. The induced modifications are mainly due to electronic energy loss and the results are discussed.

  1. Transport of proteins into chloroplasts. Import and maturation of precursors to the 33-, 23-, and 16-kDa proteins of the photosynthetic oxygen-evolving complex.

    PubMed

    James, H E; Bartling, D; Musgrove, J E; Kirwin, P M; Herrmann, R G; Robinson, C

    1989-11-25

    The 33-, 23-, and 16-kDa proteins of the photosynthetic oxygen-evolving complex are synthesized as precursors in the cytoplasm and transported into the thylakoid lumen of higher plant chloroplasts. In this report we have analyzed the import and maturation of these precursors, using reconstituted protein import assays and partially purified preparations of the processing peptidases involved. Precursors of the 33- and 23-kDa proteins from Spinacia and Triticum aestivum are processed by a stromal peptidase to intermediate forms; polypeptides of similar size are observed during the transport of these precursors and possibly that of the 16-kDa protein, into isolated chloroplasts. Complete maturation of the 33- and 23-kDa proteins is carried out by a thylakoidal peptidase shown previously to be involved in plastocyanin biogenesis. The data support an import mechanism involving successive cleavages by the stromal and thylakoidal processing peptidases. PMID:2684958

  2. Haematological and biochemical reference intervals for free-ranging brown bears (Ursus arctos) in Sweden

    PubMed Central

    2014-01-01

    Background Establishment of haematological and biochemical reference intervals is important to assess health of animals on individual and population level. Reference intervals for 13 haematological and 34 biochemical variables were established based on 88 apparently healthy free-ranging brown bears (39 males and 49 females) in Sweden. The animals were chemically immobilised by darting from a helicopter with a combination of medetomidine, tiletamine and zolazepam in April and May 2006–2012 in the county of Dalarna, Sweden. Venous blood samples were collected during anaesthesia for radio collaring and marking for ecological studies. For each of the variables, the reference interval was described based on the 95% confidence interval, and differences due to host characteristics sex and age were included if detected. To our knowledge, this is the first report of reference intervals for free-ranging brown bears in Sweden. Results The following variables were not affected by host characteristics: red blood cell, white blood cell, monocyte and platelet count, alanine transaminase, amylase, bilirubin, free fatty acids, glucose, calcium, chloride, potassium, and cortisol. Age differences were seen for the majority of the haematological variables, whereas sex influenced only mean corpuscular haemoglobin concentration, aspartate aminotransferase, lipase, lactate dehydrogenase, β-globulin, bile acids, triglycerides and sodium. Conclusions The biochemical and haematological reference intervals provided and the differences due to host factors age and gender can be useful for evaluation of health status in free-ranging European brown bears. PMID:25139149

  3. Effect of VM-26 on the haematological responses of mice to L1210 leukaemia.

    PubMed Central

    Hacker, M.; Roberts, D.; Jackson, C. W.

    1980-01-01

    The haematological responses of BDF1 mice were monitored after i.v. or i.p. inoculation of L1210 leukaemic cells. Although a marked decrease in haematocrit was observed in mice given L1210 by either route, the anaemia was most pronounced after the i.p. route. The leucocyte count was more markedly increased after i.v. inoculation than after i.p. inoculation. The number of platelets decreased following either route, but was more depressed by i.v. inoculation. When mice were treated with VM-26 on Day 4 and i.p. inoculation of 10(6) L1210 cells, the haematological responses were altered. VM-26 prevented the accumulation of haemorrhagic ascites fluid and the precipitous decline in haemotacrit. However, the number of leucocytes increased dramatically, most significantly during the 48 h before death. VM-26 caused a temporary restoration of platelet count to near baseline levels. By the time of death, however, a second decrease in platelets had occurred. The results suggest that the haematological response of mice to L1210 leukaemic cells varies according to the route of inoculation, and that these tumour-induced haematological responses of the host can be modified by treatment with VM-26. PMID:7459207

  4. Haematological values of post-laying Arrau turtle (Podocnemis expansa) in the Orinoco River, Venezuela.

    PubMed

    Rossini, M; Blanco, P A; Marín, E; Comerma-Steffensen, S; Zerpa, H

    2012-02-01

    The Arrau turtle (Podocnemis expansa) is an endangered species, as a result of long-lasting, unsustainable exploitation. To obtain reference haematological values from the wild Podocnemis expansa during post-laying, 20 turtles were captured in the Orinoco River. Blood was obtained from the dorsal cervical sinus in lithium heparin tubes. Red blood cells (RBC), white blood cells (WBC), thrombocytes (TC), packed cell volume (PCV), plasmatic protein (PP), haemoglobin (Hgb), mean corpuscular volume (MCV) and differential leukocyte count were determined. Haematological values were: RBC 0.9×10(9)/L, WBC 5.7×10(9)/L, TC 5.4×10(9)/L, PCV 35.6%, PP 4.2g/dL, Hgb 11.8g/dL, MCV 411fL. The differential leukocyte count comprised: 71% heterophils, 23% lymphocytes, 3% eosinophils, 1.6% basophils, and 1% monocytes. The reports of reference haematology values for the wild P. expansa are limited; therefore, the results presented herein contrast with those values obtained in captivity. This study represents a contribution to the referential haematological values of the wild P. expansa. PMID:21122881

  5. The haematology of hyperthyroidism: abnormalities of erythrocytes, leucocytes, thrombocytes and haemostasis.

    PubMed Central

    Ford, H. C.; Carter, J. M.

    1988-01-01

    The abnormalities of erythrocytes, leucocytes, thrombocytes and coagulation that have been reported, particularly in more recent years, to be associated with hyperthyroidism are surveyed. Several areas are highlighted where further investigations could lead to clinically useful insights, improved information about the haematological processes involved or to a better understanding of thyroid hormone action. PMID:3076660

  6. Sample stability for complete blood cell count using the Sysmex XN haematological analyser

    PubMed Central

    Daves, Massimo; Zagler, Elmar M.; Cemin, Roberto; Gnech, Flora; Joos, Alexandra; Platzgummer, Stefan; Lippi, Giuseppe

    2015-01-01

    Background Sample stability is a crucial aspect for the quality of results of a haematology laboratory. This study was conducted to investigate the reliability of haematological testing using Sysmex XN in samples stored for up to 24 h at different temperatures. Materials and methods Haematological tests were performed on whole blood samples collected from 16 ostensibly healthy outpatients immediately after collection and 3 h, 6 h or 24 h afterwards, with triple aliquots kept at room temperature, 4 °C or 37 °C. Results No meaningful bias was observed after 3 h under different storage conditions, except for red blood cell distribution width (RDW) and platelet count (impedance technique, PLT-I) at 37 °C. After 6 h, meaningful bias was observed for mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) at room temperature, red blood cell (RBC) count, mean corpuscular haemoglobin concentration (MCHC), MCH, MCV and PLT-I at 4 °C, and RBC, RDW, MCHC, MCH and PLT-I at 37 °C. After 24 h, a meaningful bias was observed for MCHC, MCV, platelet count (fluorescent technique, PLT-F) and mean platelet volume (MPV) at room temperature, MCHC, MCV, PLT-I and MPV at 4 °C, and all parameters except RBC count and MPV at 37 °C. Discussion Great caution should be observed when analysing results of haematological tests conducted more than 3 h after sample collection. PMID:26057491

  7. Ionic Conductivity of Mesostructured Yttria-Stabilized Zirconia Thin Films with Cubic Pore Symmetry—On the Influence of Water on the Surface Oxygen Ion Transport.

    PubMed

    Elm, Matthias T; Hofmann, Jonas D; Suchomski, Christian; Janek, Jürgen; Brezesinski, Torsten

    2015-06-10

    Thermally stable, ordered mesoporous thin films of 8 mol % yttria-stabilized zirconia (YSZ) were prepared by solution-phase coassembly of chloride salt precursors with an amphiphilic diblock copolymer using an evaporation-induced self-assembly process. The resulting material is of high quality and exhibits a well-defined three-dimensional network of pores averaging 24 nm in diameter after annealing at 600 °C for several hours. The wall structure is polycrystalline, with grains in the size range of 7 to 10 nm. Using impedance spectroscopy, the total electrical conductivity was measured between 200 and 500 °C under ambient atmosphere as well as in dry atmosphere for oxygen partial pressures ranging from 1 to 10(-4) bar. Similar to bulk YSZ, a constant ionic conductivity is observed over the whole oxygen partial pressure range investigated. In dry atmosphere, the sol-gel derived films have a much higher conductivity, with different activation energies for low and high temperatures. Overall, the results indicate a strong influence of the surface on the transport properties in cubic fluorite-type YSZ with high surface-to-volume ratio. A qualitative defect model which includes surface effects (annihilation of oxygen vacancies as a result of water adsorption) is proposed to explain the behavior and sensitivity of the conductivity to variations in the surrounding atmosphere. PMID:25984884

  8. Effect of oxygen content on transport and magnetic properties of PrBaCo{sub 2}O{sub 5.50+δ}

    SciTech Connect

    Zhang, Xue; Wang, Xiao-Ming; Wei, Heng-Wei; Lin, Xiao-Huan; Wang, Chun-Hai; Zhang, Yan; Chen, Chinping; Jing, Xi-Ping

    2015-05-15

    Samples of PrBaCo{sub 2}O{sub 5.50+δ} (δ = −0.15–0.14), synthesized by solid-state reactions, were investigated to ascertain oxygen compositional effects on transport/magnetic properties. Resistivity decreases with increasing oxygen content, indicative of p-type conduction. A metal-insulator transition was observed at 330 K only for sample PrBaCo{sub 2}O{sub 5.52}, coinciding with phase transition and spin-state transition of Co{sup 3+}. When δ deviates from zero, samples show insulator–insulator transitions, although for sample δ = 0.14, no transition occurs but only semi-conductive behavior appears. Electronic transport is governed by the hopping mechanism at lower temperatures and thermal activation at higher temperatures. All samples underwent paramagnetic–ferromagnetic–antiferromagnetic transitions, except PrBaCo{sub 2}O{sub 5.64}, which only went through a paramagnetic–ferromagnetic transition. The ferromagnetic state for δ < 0 originates with the Co{sup 3+}/Co{sup 2+} super-exchange interaction; for δ > 0, it stems from the Co{sup 3+}/Co{sup 4+} double exchange interaction.

  9. Enhanced Oxygen and Hydroxide Transport in a Cathode Interface by Efficient Antibacterial Property of a Silver Nanoparticle-Modified, Activated Carbon Cathode in Microbial Fuel Cells.

    PubMed

    Li, Da; Qu, Youpeng; Liu, Jia; Liu, Guohong; Zhang, Jie; Feng, Yujie

    2016-08-17

    A biofilm growing on an air cathode is responsible for the decreased performance of microbial fuel cells (MFCs). For the undesired biofilm to be minimized, silver nanoparticles were synthesized on activated carbon as the cathodic catalyst (Ag/AC) in MFCs. Ag/AC enhanced maximum power density by 14.6% compared to that of a bare activated carbon cathode (AC) due to the additional silver catalysis. After operating MFCs over five months, protein content on the Ag/AC cathode was only 38.3% of that on the AC cathode, which resulted in a higher oxygen concentration diffusing through the Ag/AC cathode. In addition, a lower pH increment (0.2 units) was obtained near the Ag/AC catalyst surface after biofouling compared to 0.8 units of the AC cathode, indicating that less biofilm on the Ag/AC cathode had a minor resistance on hydroxide transported from the catalyst layer interfaces to the bulk solution. Therefore, less decrements of the Ag/AC activity and MFC performance were obtained. This result indicated that accelerated transport of oxygen and hydroxide, benefitting from the antibacterial property of the cathode, could efficiently maintain higher cathode stability during long-term operation. PMID:27441786

  10. Oxygen-driven transition from two-dimensional to three-dimensional transport behaviour in β-Li3PS4 electrolyte.

    PubMed

    Wang, Xuelong; Xiao, Ruijuan; Li, Hong; Chen, Liquan

    2016-08-01

    Solid state electrolytes with high Li ion conduction are vital to the development of all-solid-state lithium batteries. Lithium thiophosphate Li3PS4 is the parent material of a series of Li superionic conductors Li10MX2S12 (M = Ge, Sn,…; X = P, Si,…), and β-Li3PS4 shows relatively high ionic conductivity itself, though it is not room-temperature stable. The positive effects of introducing O dopants into β-Li3PS4 to stabilize the crystal phase and improve the ionic conducting behaviour are revealed in this study. With the aid of first-principles density functional theory (DFT) computations and quasi-empirical bond-valence calculations, the effects of O doping at different concentrations on the properties of β-Li3PS4 is thoroughly investigated from the aspects of lattice structures, electronic structures, ionic transport properties, the interface stability against Li and the thermodynamic stability. An oxygen-driven transition from two-dimensional to three-dimensional transport behaviour is found and the oxygen dopants play the role as a connector of 2D paths. Based on all these simulation results, hopefully our research can provide a new strategy for the modification of lithium thiophosphate solid electrolytes. PMID:27432279

  11. [Studies of the blood antioxidant system and oxygen-transporting properties of human erythrocytes during 105-day isolation].

    PubMed

    Brazhe, N A; Baĭzhumanov, A A; Parshina, E Iu; Iusipovich, A I; Akhalaia, M Ia; Iarlykova, Iu V; Labetskaia, O I; Ivanova, S M; Morukov, B V; Maksimov, G V

    2011-01-01

    Effects of strict 105-d isolation on blood antioxidant status, erythrocyte membrane processes and oxygen-binding properties of hemoglobin were studied in 6 male volunteers (25 to 40 y.o.) in ground-based simulation of a mission to Mars (experiment Mars-105). The parameters were measured using venous blood samples collected during BDC, on days 35, 70 and 105 of the experiment and on days 7 and 14-15 after its completion. Methods of biochemistry (determination of enzyme activity and thin-layer chromatography) and biophysical (laser interference microscopy, Raman spectroscopy) showed changes in relative content of lipid and phospholipid fractions suggesting growth of membrane microviscosity and increase in TBA-AP (active products of lipids peroxidation interacting with thiobarbituric acid). A significant increase in glucose-6-phosphate dehydrogenase and superoxide dismutase activities against reduction of catalase activity points to both reparative processes in erythrocytes and disbalance between the number of evolving active forms of oxygen and antioxidant protection mechanisms in cells. Hemoglobin sensitivity of oxygen and blood level of oxyhemoglobin were found to increase, too. It is presumed that adaptation of organism to stresses experienced during and after the experiment may destroy balance of the antioxidant protection systems which is conducive to oxidation of membrane phospholipids, alteration of their content, increase of membrane microviscosity and eventual failure of the gas-exchange function of erythrocytes. PMID:21675192

  12. Oxygen-Dependent Transcriptional Regulator Hap1p Limits Glucose Uptake by Repressing the Expression of the Major Glucose Transporter Gene RAG1 in Kluyveromyces lactis▿

    PubMed Central

    Bao, Wei-Guo; Guiard, Bernard; Fang, Zi-An; Donnini, Claudia; Gervais, Michel; Passos, Flavia M. Lopes; Ferrero, Iliana; Fukuhara, Hiroshi; Bolotin-Fukuhara, Monique

    2008-01-01

    The HAP1 (CYP1) gene product of Saccharomyces cerevisiae is known to regulate the transcription of many genes in response to oxygen availability. This response varies according to yeast species, probably reflecting the specific nature of their oxidative metabolism. It is suspected that a difference in the interaction of Hap1p with its target genes may explain some of the species-related variation in oxygen responses. As opposed to the fermentative S. cerevisiae, Kluyveromyces lactis is an aerobic yeast species which shows different oxygen responses. We examined the role of the HAP1-equivalent gene (KlHAP1) in K. lactis. KlHap1p showed a number of sequence features and some gene targets (such as KlCYC1) in common with its S. cerevisiae counterpart, and KlHAP1 was capable of complementing the hap1 mutation. However, the KlHAP1 disruptant showed temperature-sensitive growth on glucose, especially at low glucose concentrations. At normal temperature, 28°C, the mutant grew well, the colony size being even greater than that of the wild type. The most striking observation was that KlHap1p repressed the expression of the major glucose transporter gene RAG1 and reduced the glucose uptake rate. This suggested an involvement of KlHap1p in the regulation of glycolytic flux through the glucose transport system. The ΔKlhap1 mutant showed an increased ability to produce ethanol during aerobic growth, indicating a possible transformation of its physiological property to Crabtree positivity or partial Crabtree positivity. Dual roles of KlHap1p in activating respiration and repressing fermentation may be seen as a basis of the Crabtree-negative physiology of K. lactis. PMID:18806211

  13. Transportation.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with transportation and energy use. Its objective is for the student to be able to discuss the implication of energy usage as it applies to the area of transportation. Some topics covered are efficiencies of various transportation…

  14. The story of oxygen.

    PubMed

    Heffner, John E

    2013-01-01

    The history of oxygen from discovery to clinical application for patients with chronic lung disease represents a long and storied journey. Within a relatively short period, early investigators not only discovered oxygen but also recognized its importance to life and its role in respiration. The application of oxygen to chronic lung disease, however, took several centuries. In the modern era, physiologists pursued the chemical nature of oxygen and its physiologic interaction with cellular metabolism and gas transport. It took brazen clinicians, however, to pursue oxygen as a therapeutic resource for patients with chronic lung disease because of the concern in the 20th century of the risks of oxygen toxicity. Application of ambulatory oxygen devices allowed landmark investigations of the long-term effects of continuous oxygen that established its safety and efficacy. Although now well established for hypoxic patients, many questions remain regarding the benefits of oxygen for varying severity and types of chronic lung disease. PMID:23271817

  15. Study of transport of oxygen and water vapour between cells in valve regulated lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Culpin, Barry; Peters, Ken

    Valve-regulated lead-acid batteries are maintenance free, safer, office compatible, and have higher volume efficiency than conventional designs. They are universally used in telecommunications and uninterruptible power supply systems. With the electrolyte immobilized in the separator or as a gel, it is feasible for a monobloc battery to have cells that are not fully sealed from one another, that is to have a common gas space, with certain attendant benefits. This study demonstrates that small differences in the saturation level, acid strength or operating temperature of the cells in such designs can initiate a cycle that may subsequently result in failure if the movement of oxygen and water vapour between cells is unrestricted. Cells that are initially out-of-balance will go further out-of-balance at an ever-increasing rate. This situation can also arise in monobloc designs with sealed cells if the intercell seal is inadequate or incomplete. Battery failure is associated with a re-distribution of water between the cells with some drying out and having high impedance. The preferential oxygen absorption in those cells produces heavily sulfated negative plates. Results on batteries tested under a range of overcharge conditions and temperatures are presented to illustrate these effects. The rate at which the cycle occurs depends on the initial relative density of the acid, the temperature or saturation imbalance between the cells, and the size of the interconnecting gas space. Batteries operating under a continuous cycling regime, particularly those with high overcharge currents and voltages that generate large volumes of oxygen, are more prone to this type of failure mode than batteries operating under low overcharge, intermittent cycling, or float conditions.

  16. Diffusion of a multi-species component and its role in oxygen and water transport in silicates

    NASA Technical Reports Server (NTRS)

    Zhang, Youxue; Stolper, E. M.; Wasserburg, G. J.

    1991-01-01

    The diffusion of a multispecies component is complicated by the different diffusion coefficient of each species and the interconversion reactions among the species. A diffusion equation is derived that incorporates the diffusive fluxes of all species contributing to the component's concentration. The effect of speciation on diffusion is investigated experimentally by measuring concentration profiles of all species developed during diffusion experiments. Data on water diffusion in rhyolitic glasses indicate that H2O molecules predominate over OH groups as the diffusing species at very low to high water concentrations. A simple theoretical relationship is drawn between the effective total oxygen diffusion coefficient and the total water concentration of silicates at low water content.

  17. Employing dobutamine as a useful agent to reverse the terlipressin-linked impairments in cardiopulmonary hemodynamics and global oxygen transport in healthy and endotoxemic sheep.

    PubMed

    Bröking, Katrin; Lange, Matthias; Morelli, Andrea; Ertmer, Christian; Aken, Hugo Van; Luecke, Martin; Rehberg, Sebastian; Böwering, Norman; Bone, Hans-Georg; Traber, Daniel L; Westphal, Martin

    2008-01-01

    Although arginine vasopressin and terlipressin have been identified as useful nonadrenergic agents to increase systemic blood pressure in catchecholamine-resistant septic shock, the impairments in cardiac index (CI) and global oxygen transport may limit their clinical applicability. The present study was designed as a prospective controlled laboratory experiment to investigate the effects of dobutamine as an adjunct to terlipressin infusion on cardiopulmonary hemodynamics and global oxygen transport in healthy and endotoxemic sheep. Nine adult ewes were instrumented for chronic study using an established protocol. After a baseline measurement in the healthy state had been performed, 1 mg terlipressin was given as bolus infusion. Thirty minutes later, dobutamine was continuously infused at incremental doses (2 and 5 microg x kg(1) x min(1), each for 1 h). After 24 h of recovery, a hypotensive-hyperdynamic circulation was induced and maintained by a continuous infusion of Salmonella typhosa endotoxin (10 ng x kg(1) x min(1)). After 16 h of endotoxemia, the six surviving sheep received terlipressin and dobutamine according to the same protocol that was used in healthy sheep. Compared with baseline, terlipressin infusion was associated with a significant increase in MAP that, however, occurred at the expense of a compromised CI, oxygen delivery index (DO(2)I), and mixed venous oxygen saturation (SvO(2), each P < 0.05). Dobutamine infusion was followed by a dose-dependent increase in CI, DO(2)I, and SvO(2) in both health and endotoxemia (each P < 0.05). Although the higher dosage of dobutamine exerted favorable effects, such as a decrease in pulmonary vascular resistance index (P < 0.05), the associated onset of tachycardia (P < 0.05) and arterial hypotension (P < 0.05) may limit its therapeutic use under septic conditions. This study provides evidence that dobutamine in a dosage of 2 microg x kg(1) x min(1) is useful to reverse the terlipressin-linked depressions in CI

  18. Oxygen transport resistance at gas diffusion layer - Air channel interface with film flow of water in a proton exchange membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Koz, Mustafa; Kandlikar, Satish G.

    2016-01-01

    Water present as films on the gas diffusion layer-air channel interface in a proton exchange membrane fuel cell (PEMFC) alters the oxygen transport resistance, which is expressed through Sherwood number (Sh). The effect of multiple films along the flow length on Sh is investigated through 3D and stationary simulations. The effects of air Péclet number, non-dimensional film width, length, and spacing are studied. Using the simulation results, non-dimensional correlations are developed for local Sh within a mean absolute percentage error of 9%. These correlations can be used for simulating PEMFC performance over temperature and relative humidity ranges of 20-80 °C and 0-100%, respectively. Sh on the film side can be up to 31% lower than that for a dry channel, while a film may reduce the interfacial width by up to 39%. The corresponding increase in transport resistance results in lowering the voltage by 5 and 8 mV respectively at a current density of 1.5 A cm-2. However, their combined effect leads to a voltage loss of 20 mV due to this additional mass transport resistance. It is therefore important to incorporate the additional resistance introduced by the films while modeling fuel cell performance.

  19. Hypothermia protects against oxygen-glucose deprivation-induced neuronal injury by down-regulating the reverse transport of glutamate by astrocytes as mediated by neurons.

    PubMed

    Wang, D; Zhao, Y; Zhang, Y; Zhang, T; Shang, X; Wang, J; Liu, Y; Kong, Q; Sun, B; Mu, L; Liu, X; Wang, G; Li, H

    2013-05-01

    Glutamate is the major mediator of excitotoxic neuronal death following cerebral ischemia. Under severe ischemic conditions, glutamate transporters can functionally reverse to release glutamate, thereby inducing further neuronal injury. Hypothermia has been shown to protect neurons from brain ischemia. However, the mechanism(s) involved remain unclear. Therefore, the aim of this study was to investigate the mechanism(s) mediating glutamate release during brain ischemia-reperfusion injury under hypothermic conditions. Neuron/astrocyte co-cultures were exposed to oxygen-glucose deprivation (OGD) at various temperatures for 2h, and cell viability was assayed 12h after reoxygenation. PI and MAP-2 staining demonstrated that hypothermia significantly decreased neuronal injury. Furthermore, [(3)H]-glutamate uptake assays showed that hypothermia protected rat primary cortical cultures against OGD reoxygenation-induced injury. Protein levels of the astrocytic glutamate transporter, GLT-1, which is primarily responsible for the clearance of extracellular glutamate, were also found to be reduced in a temperature-dependent manner. In contrast, expression of GLT-1 in astrocyte-enriched cultures was found to significantly increase following the addition of neuron-conditioned medium maintained at 37 °C, and to a lesser extent with neuron-conditioned medium at 33 °C. In conclusion, the neuroprotective effects of hypothermia against brain ischemia-reperfusion injury involve down-regulation of astrocytic GLT-1, which mediates the reverse transport of glutamate. Moreover, this process may be regulated by molecules secreted by stressed neurons. PMID:23402854

  20. Electronic Transport Properties of the PrAlO3/SrTiO3 Interface: Effects of Oxygen Pressure

    NASA Astrophysics Data System (ADS)

    Mozaffari, Shirin; Monti, Mark C.; Guchhait, Samaresh; Paster, Jeremy W.; Tennant, Daniel M.; Markert, John T.

    2015-03-01

    We explored the electronic and magnetic behavior of epitaxial PrAlO3 films on TiO2-terminated SrTiO3 (PAO/STO) substrates grown by pulsed laser deposition at various oxygen pressures. We report structural (x-ray and AFM), electronic (van der Pauw resistivity, magnetoresistance (MR), and Hall effect), and magnetic data for PAO films grown in 10-3-10-6 torr O2. Resistivity data exhibit metallic behavior from 300 K down to 100-150 K (75 K; 40 K) for the interface grown in 10-3 (10-4; 10-5) torr O2, and semiconducting behavior below that. One 10-3 torr O2 interface shows typical behavior for current parallel to atomic terraces, and a resistance anomaly in the range 50-100 K for current perpendicular to step edges. MR data for all 10-3-10-4 torr O2 samples show a small (<=0.5%) positive MR at low fields, and a larger negative MR (2-30%) at high fields; for 10-5 torr O2, the MR is positive up to 9 tesla. Sheet resistivity for the 10-6 torr O2 interface is anomalously low, suggesting a thick conducting layer. Hall effect data exhibit several variations in the carrier density. We discuss these data considering intrinsic charge transfer, oxygen vacancies and interstitials, and cation interdiffusion.

  1. Replacement of a cytosolic copper/zinc superoxide dismutase by a novel cytosolic manganese superoxide dismutase in crustaceans that use copper (haemocyanin) for oxygen transport.

    PubMed Central

    Brouwer, Marius; Hoexum Brouwer, Thea; Grater, Walter; Brown-Peterson, Nancy

    2003-01-01

    The blue crab, Callinectes sapidus, which uses the copper-dependent protein haemocyanin for oxygen transport, lacks the ubiquitous cytosolic copper-dependent enzyme copper/zinc superoxide dismutase (Cu,ZnSOD) as evidenced by undetectable levels of Cu,ZnSOD activity, protein and mRNA in the hepatopancreas (the site of haemocyanin synthesis) and gills. Instead, the crab has an unusual cytosolic manganese SOD (cytMnSOD), which is retained in the cytosol, because it lacks a mitochondrial transit peptide. A second familiar MnSOD is present in the mitochondria (mtMnSOD). This unique phenomenon occurs in all Crustacea that use haemocyanin for oxygen transport. Molecular phylogeny analysis suggests the MnSOD gene duplication is as old as the origin of the arthropod phylum. cytMnSOD activity in the hepatopancreas changes during the moulting cycle of the crab. Activity is high in intermoult crabs and non-detectable in postmoult papershell crabs. mtMnSOD is present in all stages of the moulting cycle. Despite the lack of cytCu,ZnSOD, crabs have an extracellular Cu,ZnSOD (ecCu,ZnSOD) that is produced by haemocytes, and is part of a large, approx. 160 kDa, covalently-linked protein complex. ecCu,ZnSOD is absent from the hepatopancreas of intermoult crabs, but appears in this tissue at premoult. However, no ecCu,ZnSOD mRNA can be detected, suggesting that the protein is recruited from the haemolymph. Screening of different taxa of the arthropod phylum for Cu,ZnSOD activity shows that those crustaceans that use haemoglobin for oxygen transport have retained cytCu,ZnSOD. It appears, therefore, that the replacement of cytCu,ZnSOD with cytMnSOD is part of an adaptive response to the dynamic, haemocyanin-linked, fluctuations in copper metabolism that occur during the moulting cycle of the crab. PMID:12769817

  2. Structure and transport in high pressure oxygen sputter-deposited BaSnO{sub 3−δ}

    SciTech Connect

    Ganguly, Koustav; Ambwani, Palak; Xu, Peng; Jeong, Jong Seok; Mkhoyan, K. Andre; Leighton, C. E-mail: leighton@umn.edu; Jalan, Bharat E-mail: leighton@umn.edu

    2015-06-01

    BaSnO{sub 3} has recently been identified as a high mobility wide gap semiconductor with significant potential for room temperature oxide electronics. Here, a detailed study of the high pressure oxygen sputter-deposition, microstructure, morphology, and stoichiometry of epitaxial BaSnO{sub 3} on SrTiO{sub 3}(001) and MgO(001) is reported, optimized conditions resulting in single-phase, relaxed, close to stoichiometric films. Most significantly, vacuum annealing is established as a facile route to n-doped BaSnO{sub 3−δ}, leading to electron densities above 10{sup 19} cm{sup −3}, 5 mΩ cm resistivities, and room temperature mobility of 20 cm{sup 2} V{sup −1} s{sup −1} in 300-Å-thick films on MgO(001). Mobility limiting factors, and the substantial scope for their improvement, are discussed.

  3. A Highly Efficient Sandwich-Like Symmetrical Dual-Phase Oxygen-Transporting Membrane Reactor for Hydrogen Production by Water Splitting.

    PubMed

    Fang, Wei; Steinbach, Frank; Cao, Zhongwei; Zhu, Xuefeng; Feldhoff, Armin

    2016-07-18

    Water splitting coupled with partial oxidation of methane (POM) using an oxygen-transporting membrane (OTM) would be a potentially ideal way to produce high-purity hydrogen as well as syngas. Over the past decades, substantial efforts have been devoted to the development of supported membranes with appropriate configurations to achieve considerable performance improvements. Herein, we describe the design of a novel symmetrical membrane reactor with a sandwich-like structure, whereby a largescale production (>10 mL min(-1)  cm(-2) ) of hydrogen and syngas can be obtained simultaneously on opposite sides of the OTM. Furthermore, this special membrane reactor could regenerate the coke-deactivated catalyst in situ by water steam in a single unit. These results represent an important first step in the development of membrane separation technologies for the integration of multiple chemical processes. PMID:27244216

  4. Neuroprotection Promoted by Guanosine Depends on Glutamine Synthetase and Glutamate Transporters Activity in Hippocampal Slices Subjected to Oxygen/Glucose Deprivation.

    PubMed

    Dal-Cim, Tharine; Martins, Wagner C; Thomaz, Daniel T; Coelho, Victor; Poluceno, Gabriela Godoy; Lanznaster, Débora; Vandresen-Filho, Samuel; Tasca, Carla I

    2016-05-01

    Guanosine (GUO) has been shown to act as a neuroprotective agent against glutamatergic excitotoxicity by increasing glutamate uptake and decreasing its release. In this study, a putative effect of GUO action on glutamate transporters activity modulation was assessed in hippocampal slices subjected to oxygen and glucose deprivation (OGD), an in vitro model of brain ischemia. Slices subjected to OGD showed increased excitatory amino acids release (measured by D-[(3)H]aspartate release) that was prevented in the presence of GUO (100 µM). The glutamate transporter blockers, DL-TBOA (10 µM), DHK (100 µM, selective inhibitor of GLT-1), and sulfasalazine (SAS, 250 µM, Xc(-) system inhibitor) decreased OGD-induced D-aspartate release. Interestingly, DHK or DL-TBOA blocked the decrease in glutamate release induced by GUO, whereas SAS did not modify the GUO effect. GUO protected hippocampal slices from cellular damage by modulation of glutamate transporters, however selective blockade of GLT-1 or Xc- system only did not affect this protective action of GUO. OGD decreased hippocampal glutamine synthetase (GS) activity and GUO recovered GS activity to control levels without altering the kinetic parameters of GS activity, thus suggesting GUO does not directly interact with GS. Additionally, the pharmacological inhibition of GS activity with methionine sulfoximine abolished the effect of GUO in reducing D-aspartate release and cellular damage evoked by OGD. Altogether, results in hippocampal slices subjected to OGD show that GUO counteracts the release of excitatory amino acids, stimulates the activity of GS, and decreases the cellular damage by modulation of glutamate transporters activity. PMID:26858177

  5. Red blood cell pH, the Bohr effect, and other oxygenation-linked phenomena in blood O2 and CO2 transport.

    PubMed

    Jensen, F B

    2004-11-01

    The discovery of the S-shaped O2 equilibrium curve and the Bohr effect in 1904 stimulated a fertile and continued research into respiratory functions of blood and allosteric mechanisms in haemoglobin (Hb). The Bohr effect (influence of pH/CO2 on Hb O2 affinity) and the reciprocal Haldane effect (influence of HbO2 saturation on H+/CO2 binding) originate in the Hb oxy-deoxy conformational change and allosteric interactions between O2 and H+/CO2 binding sites. In steady state, H+ is passively distributed across the vertebrate red blood cell (RBC) membrane, and intracellular pH (pHi) changes are related to changes in extracellular pH, Hb-O2 saturation and RBC organic phosphate content. As the Hb molecule shifts between the oxy and deoxy conformation in arterial-venous gas transport, it delivers O2 and takes up CO2 and H+ in tissue capillaries (elegantly aided by the Bohr effect). Concomitantly, the RBC may sense local O2 demand via the degree of Hb deoxygenation and release vasodilatory agents to match local blood flow with requirements. Three recent hypotheses suggest (1) release of NO from S-nitroso-Hb upon deoxygenation, (2) reduction of nitrite to vasoactive NO by deoxy haems, and (3) release of ATP. Inside RBCs, carbonic anhydrase (CA) provides fast hydration of metabolic CO2 and ensures that the Bohr shift occurs during capillary transit. The formed H+ is bound to Hb (Haldane effect) while HCO3- is shifted to plasma via the anion exchanger (AE1). The magnitude of the oxylabile H+ binding shows characteristic differences among vertebrates. Alternative strategies for CO2 transport include direct HCO3- binding to deoxyHb in crocodilians, and high intracellular free [HCO3-] (due to high pHi) in lampreys. At the RBC membrane, CA, AE1 and other proteins may associate into what appears to be an integrated gas exchange metabolon. Oxygenation-linked binding of Hb to the membrane may regulate glycolysis in mammals and perhaps also oxygen-sensitive ion transport involved in

  6. Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water on Pt(111): Precursor Transport Through the Hydrogen Bonding Network

    SciTech Connect

    Petrik, Nikolay G.; Kavetski, Alexandre G.; Kimmel, Greg A.

    2006-09-28

    The low-energy, electron-stimulated production of molecular oxygen from thin amorphous solid water (ASW) films adsorbed on Pt(111) is investigated. For ASW coverages less than {approx}60 monolayers (ML), the O2 ESD yield depends on coverage in a manner that is very similar to the H2 ESD yield. In particular, both the O2 and H2 ESD yields have a pronounced maximum at {approx}20 ML due to reactions at the Pt/water interface. The O2 yield is dose-dependent and several precursors (OH, H2O2 and HO2) are involved in the O2 production. Layered films of H216O and H218O are used to profile the spatial distribution of the electron-stimulated reactions leading to oxygen within the water films. Independent of the ASW film thickness, the final reactions leading to O2 occur at or near the ASW/vacuum interface. However for ASW coverages less than {approx}40 ML, the results indicate that dissociation of water molecules at the ASW/Pt interface contributes to the O2 production at the ASW/vacuum interface presumably via the generation of OH radicals near the Pt substrate. The OH (or possibly OH-) segregates to the vacuum interface where it contributes to the reactions at that interface. The electron-stimulated migration of precursors to the vacuum interface occurs via transport through the hydrogen bond network of the ASW without motion of the oxygen atoms. A simple kinetic model of the non-thermal reactions leading to O2, which was previously used to account for reactions in thick ASW films, is modified to account for the electron-stimulated migration of precursors.

  7. The impact of cell-specific absorption properties on the correlation of electron transport rates measured by chlorophyll fluorescence and photosynthetic oxygen production in planktonic algae.

    PubMed

    Blache, Ulrich; Jakob, Torsten; Su, Wanwen; Wilhelm, Christian

    2011-08-01

    Photosynthesis-irradiance (P-E)-curves describe the photosynthetic performance of autotrophic organisms. From these P-E-curves the photosynthetic parameters α-slope, P(max), and E(k) can be deduced which are often used to characterize and to compare different organisms or organisms in acclimation to different environmental conditions. Particularly, for in situ-measurements of P-E curves of phytoplankton the analysis of variable chlorophyll fluorescence proved its potential as a sensitive and rapid method. By using Chlorella vulgaris (Trebouxiophyceae), Nannochloropsis salina (Eustigmatophyceae), Skeletonema costatum and Cyclotella meneghiniana (Bacillariophyceae), the present study investigated the influence of cellular bio-optical properties on the correlation of the photosynthetic parameters derived from fluorescence-based P-E-curves with photosynthetic parameters obtained from the measurement of oxygen evolution. It is demonstrated that small planktonic algae show a wide range of cellular absorptivity which was subject to species-specifity, growth stage and environmental conditions, e.g. nutrient limitation. This variability in bio-optical properties resulted in a great deviation of relative electron transport rates (rETRs) from oxygen-based photosynthesis rates. Thus, the photosynthetic parameters α-slope and P(max) derived from rETRs strongly depend on the specific cellular absorptivity and cannot be used to compare the photosynthetic performance of cells with different optical properties. However, it was shown that E(k) is independent of cellular absorptivity and could be used to compare samples with unknown optical properties. PMID:21571541

  8. Regulation of energy partitioning and alternative electron transport pathways during cold acclimation of lodgepole pine is oxygen dependent.

    PubMed

    Savitch, Leonid V; Ivanov, Alexander G; Krol, Marianna; Sprott, David P; Oquist, Gunnar; Huner, Norman P A

    2010-09-01

    Second year needles of Lodgepole pine (Pinus contorta L.) were exposed for 6 weeks to either simulated control summer ['summer'; 25 °C/250 photon flux denisty (PFD)], autumn ('autumn'; 15°C/250 PFD) or winter conditions ('winter'; 5 °C/250 PFD). We report that the proportion of linear electron transport utilized in carbon assimilation (ETR(CO2)) was 40% lower in both 'autumn' and 'winter' pine when compared with the 'summer' pine. In contrast, the proportion of excess photosynthetic linear electron transport (ETR(excess)) not used for carbon assimilation within the total ETR(Jf) increased by 30% in both 'autumn' and 'winter' pine. In 'autumn' pine acclimated to 15°C, the increased amounts of 'excess' electrons were directed equally to 21  kPa O2-dependent and 2  kPa O2-dependent alternative electron transport pathways and the fractions of excitation light energy utilized by PSII photochemistry (Φ(PSII)), thermally dissipated through Φ(NPQ) and dissipated by additional quenching mechanism(s) (Φ(f,D)) were similar to those in 'summer' pine. In contrast, in 'winter' needles acclimated to 5 °C, 60% of photosynthetically generated 'excess' electrons were utilized through the 2  kPa O2-dependent electron sink and only 15% by the photorespiratory (21  kPa O2) electron pathway. Needles exposed to 'winter' conditions led to a 3-fold lower Φ(PSII), only a marginal increase in Φ(NPQ) and a 2-fold higher Φ(f,D), which was O2 dependent compared with the 'summer' and 'autumn' pine. Our results demonstrate that the employment of a variety of alternative pathways for utilization of photosynthetically generated electrons by Lodgepole pine depends on the acclimation temperature. Furthermore, dissipation of excess light energy through constitutive non-photochemical quenching mechanisms is O2 dependent. PMID:20630988

  9. Biosimilar Epoetin Zeta in Oncology and Haematology: Development and Experience following 6 Years of Use.

    PubMed

    Michallet, Mauricette; Losem, Christoph

    2016-01-01

    Chemotherapy-induced anaemia is frequent in cancer patients, with severity depending on the extent of the disease and intensity of treatment. Clinical guidelines recommend erythropoietin therapy to treat or prevent anaemia in some oncology/haematology patients being treated with chemotherapy. The patent expiry of the first-generation erythropoietins has led to the development of biosimilar products, i.e. therapeutic proteins exhibiting comparable quality, safety and efficacy to an existing reference biological medicine, the patent of which has expired. This review summarises the available data set supporting the use of one such biosimilar product, epoetin zeta (Retacrit™) in oncology/haematology. The body of evidence supporting the use of epoetin zeta continues to grow, with post-marketing clinical studies underway to evaluate its longer-term clinical efficacy and safety. Biosimilar medicines have the potential to offer cost savings to health care providers, with the assurance of ongoing risk management programmes to ensure patient safety. PMID:26426164

  10. Invasive pneumococcal disease in patients with haematological malignancies before routine use of conjugate vaccines in Finland.

    PubMed

    Lindström, Vesa; Aittoniemi, Janne; Lyytikäinen, Outi; Klemets, Peter; Ollgren, Jukka; Silvennoinen, Raija; Nuorti, J Pekka; Sinisalo, Marjatta

    2016-05-01

    The baseline national invasive pneumococcal disease (IPD) incidence rate, serotype distribution and serotype coverage of pneumococcal vaccines were evaluated in patients with Hodgkin's and non-Hodgkin's lymphomas, myeloma and leukaemia within 1 year after haematological diagnosis during 1995-2002, before introduction of pneumococcal conjugate vaccines. Pneumococcal serotype distribution among these patients was different from serotypes causing IPD in the general population. The serotype coverages of PCV13 and PPSV23 were 57% and 64%, respectively, lower than in the general population. This reflects a higher predisposition to IPD in vaccinated patients with haematological malignancies and possibly less benefit of herd immunity gained with the wide use of pneumococcal conjugate vaccines in the general population. This data will be useful as a baseline for determining the future role of adult PCV vaccination in these patient groups. PMID:26635103

  11. Normal haematology and blood biochemistry of wild Nile crocodiles (Crocodylus niloticus) in the Okavango Delta, Botswana.

    PubMed

    Lovely, C J; Pittman, J M; Leslie, A J

    2007-09-01

    Wild Nile crocodiles (Crocodylus niloticus) of various size classes were captured in the Okavango Delta, Botswana. Blood was collected from the post occipital sinus and used for the determination of a wide range of haematological and biochemical parameters. These values were compared between the sexes and between 3 size classes. The values were also compared with the limited data available from farmed Nile crocodiles, as well as from other wild Nile crocodiles. The Okavango crocodiles were comparatively anaemic, and had comparatively low total protein and blood glucose levels. There was a high prevalence of Hepatozoon pettiti infection, however, there was no significant difference in haematological values between the infected and uninfected crocodiles. The values reported here will be useful in diagnostic investigations in both zoo and farmed Nile crocodiles. PMID:18237036

  12. Haematology and blood chemistry of Cebus apella in relation to sex and age.

    PubMed

    Riviello, M C; Wirz, A

    2001-12-01

    An effective health care program entails the prevention, diagnosis and treatment of medical problems. A knowledge of baseline values in clinically normal individuals is essential for determining the limits between good health and disease and for understanding the changes produced by pathogenic agents. However, very little information is currently available concerning the blood chemistry and haematological values of different species of monkeys, particularly new-world primates. The values of some haematological and chemical parameters in Cebus apella were determined. The aim of the present work was to verify the effect of age and sex on normal blood values. Blood samples were collected once a year for two successive years from 36 monkeys living in large captive social groups. Significant differences between males and females were found for AST, GGT, urea nitrogen and creatinine, erythrocytes, haemoglobin and haematocrit. Significant differences between juveniles and adults were found for calcium, AST, alkaline phosphatase, inorganic phosphorus, glucose, neutrophils, lymphocytes and serum protein parameters. PMID:11990530

  13. Effects of ginseng extract on various haematological parameters during aerobic exercise in the rat.

    PubMed

    Ferrando, A; Vila, L; Voces, J A; Cabral, A C; Alvarez, A I; Prieto, J G

    1999-04-01

    The effects of the Ginseng extract on various biochemical and haematological parameters in male Wistar rats subjected to a treadmill exercise protocol were studied for 12 weeks. The results showed increases in the haematological parameters, these increases being greatest for the animals treated with the extract during the third month of the study. The exercise also led to increases in these parameters, while the combination of both exercise and extract produced smaller increases. This study shows a clear physiological response due to the ginseng extract administration that reproduces many of the effects obtained after long-term exercise. The combination of exercise and treatments seems to support the theory that there is no clear synergic effect when the advantages associated with the ingestion of ginseng are compared with the performance of exercise. PMID:10232085

  14. Prognostic significance of neoplastic cell proliferation parameters in human haematological malignancies.

    PubMed

    Kotelnikov, V M

    1990-01-01

    High percentage of neoplastic cells in S, G2 and M phases of cell cycle is unfavourable prognostic sign in human haematological malignancies. In chronic leukaemias (CML and CLL) it is true for peripheral blood leukaemic cells, in non-Hodgkin lymphomas--for lymph node cells, in multiple myeloma--for bone marrow plasma cells. In acute leukaemia results are controversial: some authors found a correlation between proliferation parameters of bone marrow blast cells while others did not. These parameters correlate positively with the rate of complete remission and negatively with its duration. It is concluded that proliferation parameters of neoplastic cells may be used for individual prognosis in patients with haematological tumours especially in combination with other biological and clinical prognostic markers. PMID:1703108

  15. Oncology/haematology nurses: a study of job satisfaction, burnout, and intention to leave the specialty.

    PubMed

    Barrett, Linda; Yates, Patsy

    2002-01-01

    The impact of the current nursing shortage on the health care system is receiving attention by both state and federal governments. This study, using a convenience sample of 243 oncology/haematology nurses working in 11 Queensland health care facilities, explored factors that influence the quality of nurses' working lives. Although nurses reported high levels of personal satisfaction and personal accomplishment, results indicated that nearly 40% of registered nurses (RNs) are dealing with workloads they perceive excessive, 48% are dissatisfied regarding pay, and professional support is an issue. Furthermore, emotional exhaustion is a very real concern: over 70% of the sample experienced moderate to high levels. Over 48% of the sample could not commit to remaining in the specialty for a further 12 months. Health care managers and governments should implement strategies that can increase nurses' job satisfaction and reduce burnout, thereby enhancing the retention of oncology/haematology nurses. PMID:12136551

  16. Normal haematological and biochemical values for the swamp buffalo (Bubalus bubalis) in Australia.

    PubMed

    Canfield, P J; Best, F G; Fairburn, A J; Purdie, J; Gilham, M

    1984-03-01

    Blood samples were collected from 24 immature male, 55 immature female and 99 mature female water buffalo kept at an experimental farm in the Northern Territory. Haematological analysis was performed on blood collected in dipotassium--ethylene diamine tetra acetic acid while biochemical analysis was performed on serum and plasma (for glucose) samples. Haematological values of mature buffalo were similar to those recorded for swamp buffalo in Malaysia. Blood cell appearances were similar to those reported for adult Indian river buffalo though values recorded for red cell components were higher. Statistical analysis revealed no significant differences between immature male and female buffalo. Red cell components, eosinophils, total plasma and serum proteins, albumin, gamma globulins, inorganic phosphate and the enzyme gamma-glutamyl transferase were significantly higher for mature female buffalo when compared to immature females. Reasons for the differences were not fully determined but the effect of age and nutritional status in combination with a variable period of domestication were considered. PMID:6743148

  17. Serum biochemical and haematological reference intervals for water buffalo Bubalus bubalis heifers.

    PubMed

    Abd Ellah, Mahmoud R; Hamed, Maha I; Ibrahim, Derar R; Rateb, Hassan Z

    2014-01-01

    Based on a review of the literature, reference intervals for water buffalo (Bubalus bubalis) serum biochemistry and haematology have not previously been published. The current study was done to establish reference intervals for water buffalo heifers. The International Federation of Clinical Chemistry stated that at least 120 values are necessary to obtain reliable estimates for reference intervals. A total number of 127 clinically healthy buffalo heifers (1-2 years old) were included in the study. Animals were examined at buffalo farms that belong to Assiut Governorate, Egypt. Three types of samples were collected: serum samples for biochemical analysis, whole blood samples for haematological analysis and faecal samples for parasitological examination. Animals that fitted the inclusion criteria were included in the study. Biochemical analysis included serum total proteins, albumin, total globulins, alpha, beta and gamma globulin levels, and aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, creatine phosphokinase and lactate dehydrogenase activity. In addition to the above, serum creatinine, urea, total bilirubin, direct bilirubin, indirect bilirubin, sodium, potassium, chloride, magnesium, calcium, phosphorus, copper, zinc, iron, triglycerides, high density lipoprotein, low density lipoprotein, very low density lipoprotein, glucose levels and 20 haematological variables were measured. The 95.0% reference intervals were calculated by removing the upper and lower 2.5% of the interval for each serum biochemical constituent to give the 2.5 and 97.5 percentiles. Confidence intervals were calculated for each reference limit. Reference intervals from the current study were compared with established values for cows. The current study is as far as could be determined the first that establishes reference intervals for the serum biochemical and haematological parameters in water buffalo heifers. PMID:24831856

  18. Effects of lichen extracts on haematological parameters of rats with experimental insulin-dependent diabetes mellitus.

    PubMed

    Colak, Suat; Geyikoğlu, Fatime; Aslan, Ali; Deniz, Gülşah Yıldız

    2014-11-01

    The prevalence of diabetes mellitus in the world is steadily increasing. Oxidative stress contributes to the development of diabetic complications, including diabetic haematological changes. Lichens are used as food supplements and are also used as possible natural antioxidant, antimicrobial and anticancer agents. We hypothesized that antioxidant activity of lichens may decrease hyperglycaemia-induced oxidative stress and prevent the development of diabetic complications, including abnormality in haematological condition. Therefore, the effects of Cetraria islandica water extract (CIWE) and Pseudevernia furfuracea water extract (PFWE) on the haematological parameters of rats with type 1 DM were investigated for the first time in the present study. Control Sprague-Dawley or streptozotocin (STZ)-induced diabetic rats were either untreated or treated with water lichen extracts (5-500 mg/kg body weight (bw)/day) for 2 weeks, starting at 72 h after STZ injection. On day 14, animals were anaesthetized and haematological and metabolic parameters were determined between control and experimental groups. In addition, the total oxidative stress (TOS), a specific indicator of oxidative stress, and the total antioxidant capacity (TAC) were measured by biochemical studies. In diabetic rats, CIWE of 250-500 mg/kg bw dose showed more prominent results when compared with doses of PFWE for TAC. The results obtained in the present study suggested that the antioxidant activities of lichens might be the possible reason behind the observed antihaematological status. However, the protective effect of lichen extracts were inadequate on diabetes-induced microcytic hypochromic anaemia. In addition, the extracts have no effect on metabolic complications. Our experimental data showed that high doses of CIWE and PFWE alone have no detrimental effect on blood cells and TOS status of plasma. Hence, they are safe and suitable for different administration routes. PMID:23114377

  19. Haematological values of rusa deer (Cervus timorensis russa) in New Caledonia.

    PubMed

    Audigé, L

    1992-11-01

    Blood samples were collected from 91 rusa deer (Cervus timorensis russa), immediately after being shot, to define their mean haematological values (red cell count, white cell count, differential leucocyte count, packed cell volume, haemoglobin concentration, mean cell volume, mean cell haemoglobin, and mean cell haemoglobin concentration). Male deer had a significantly higher red cell count and haemoglobin concentration, and a lower mean cell volume and mean cell haemoglobin content, than did female deer. PMID:1288471

  20. Virologic response and haematologic toxicity of boceprevir- and telaprevir-containing regimens in actual clinical settings

    PubMed Central

    Butt, A. A.; Yan, P.; Shaikh, O. S.; Freiberg, M. S.; Re, V. Lo; Justice, A. C.; Sherman, K. E.

    2016-01-01

    SUMMARY Effectiveness, safety and tolerability of boceprevir (BOC) and telaprevir (TPV) in actual clinical settings remain unknown. We determined rates of sustained virologic response (SVR) and haematologic adverse effects among persons treated with BOC- or TPV-containing regimens, compared with pegylated interferon/ribavirin (PEG/RBV). Using an established cohort of hepatitis C virus (HCV)-infected persons, Electronically Retrieved Cohort of HCV Infected Veterans (ERCHIVES), we identified those treated with a BOC- or TPV-containing regimen and HCV genotype 1-infected controls treated with PEG/RBV. We excluded those with HIV co-infection and missing HCV RNA values to determine SVR. Primary endpoints were SVR (undetectable HCV RNA ≥12 weeks after treatment completion) and haematologic toxicity (grade 3/4 anaemia, neutropenia and thrombocytopenia). We evaluated 2288 persons on BOC-, 409 on TPV-containing regimen and 6308 on PEG/RBV. Among these groups, respectively, 31%, 43% and 9% were treatment-experienced; 17%, 37% and 14% had baseline cirrhosis; 63%, 54% and 48% were genotype 1a. SVR rates among noncirrhotics were as follows: treatment naïve: 65% (BOC), 67% (TPV) and 31% (PEG/RBV); treatment experienced: 57% (BOC), 54% (TPV) and 13% (PEG/RBV); (P-value not significant for BOC vs TPV; P < 0.0001 for BOC or TPV vs PEG/RBV). Haematologic toxicities among BOC-, TPV- and PEG/RBV-treated groups were as follows: grade 3/4 anaemia 7%, 11% and 3%; grade 4 thrombocytopenia 2.2%, 5.4% and 1.7%; grade 4 neutropenia 8.2%, 5.6% and 3.4%. SVR rates are higher and closer to those reported in pivotal clinical trials among BOC- and TPV-treated persons compared with PEG/RBV-treated persons. Haematologic adverse events are frequent, but severe toxicity is uncommon. PMID:25524834

  1. British Society for Haematology, Slide session, Annual Scientific Meeting, Bournemouth, 2007.

    PubMed

    Bhavnani, M; Braithwaite, J; Burthem, J; Crotty, G; Gibson, B; Hutchinson, C; Jackson, G H; Layton, M; Lucas, G; Macartney, C; Matthey, F; Pardoe, L; Radia, D; Webb, S

    2008-04-01

    Eight cases discussed by experts at the 2007 Annual Scientific Meeting of the British Society of Haematology are presented as at the meeting, with a discussion of the morphological features, digital information and differential diagnosis being followed by further information and a final diagnosis. Additionally, digital slides of two of the cases were available to be viewed by the internet with the opportunity for delegates to suggest diagnoses. PMID:18284418

  2. Candiduria in haematologic malignancy patients without a urinary catheter: nothing more than a frailty marker?

    PubMed

    Georgiadou, Sarah P; Tarrand, Jeffrey; Sipsas, Nikolaos V; Kontoyiannis, Dimitrios P

    2013-05-01

    There is scarcity of data regarding significance of candiduria in patients with haematologic malignancies and its association with invasive candidiasis. To that end, we retrospectively evaluated all hospitalised, non-intensive care unit patients with haematologic malignancies and candiduria during a 10-year period (2001-2011). To decrease the possibility of bladder colonisation and sample contamination, we excluded all patients with candiduria who had urinary catheters and those with concomitant bacteriuria. Twenty-four such patients (21 females) were identified, with median age at diagnosis 62 years (range, 20-82 years). Acute leukaemia was the most common underlying disease (54%); 62% of these cases were not in remission. Twenty-nine percent of the patients had diabetes mellitus and 25% were neutropenic. The most common isolated Candida species was Candida glabrata (37%), followed by C. albicans (29%). Only 8% of them had urinary tract infection symptoms. However, 88% received systemic antifungals. Candidemia and crude mortality rates at 4 weeks were low (4% and 12% respectively). Isolated candiduria in patients with haematologic malignancies has risk factors similar to those in other hospitalised patients, and it does not seem to be a strong predictor of subsequent invasive candidiasis. PMID:23170870

  3. Invasive aspergillosis: epidemiology and environmental study in haematology patients (Sfax, Tunisia).

    PubMed

    Hadrich, I; Makni, F; Sellami, H; Cheikhrouhou, F; Sellami, A; Bouaziz, H; Hdiji, S; Elloumi, M; Ayadi, A

    2010-09-01

    Invasive aspergillosis (IA) is a major opportunistic infection in haematology patients. Preventive measures are important to control IA because diagnosis is difficult and the outcome of treatment is poor. We prospectively examined the environmental contamination by Aspergillus and other fungal species and evaluated the prevalence of invasive aspergillosis in the protect unit of haematology. A three-year prospective study (December 2004-September 2007) was carried out in the department of haematology of Hedi Chaker Hospital. Suspected invasive aspergillosis cases were reviewed and classified as proven, probable and possible invasive aspergillosis using the EORTC criteria. During the study period, we collected weekly environmental samples (patient's rooms, tables and acclimatisers) and clinical samples from each patient (nasal, expectoration and auricular). Among 105 neutropenic patients, 16 had probable and 13 had possible IA. A total of 1680 clinical samples were collected and A. flavus was most frequently isolated (79.2%). Analysis of 690 environmental samples revealed that Penicillium (44%) was the most frequent followed by Cladosporium (20%), Aspergillus spp. (18%) and Alternaria (13%). The PCR-sequencing of 30 A. flavus isolates detected from clinical and environmental samples confirmed the mycological identification. Our findings underline the importance of environmental surveillance and strict application of preventive measures. PMID:19500260

  4. Utility of next-generation sequencing technologies for the efficient genetic resolution of haematological disorders.

    PubMed

    Zhang, J; Barbaro, P; Guo, Y; Alodaib, A; Li, J; Gold, W; Adès, L; Keating, B J; Xu, X; Teo, J; Hakonarson, H; Christodoulou, J

    2016-02-01

    Next-generation sequencing (NGS) has now evolved to be a relatively affordable and efficient means of detecting genetic mutations. Whole genome sequencing (WGS) or whole exome sequencing (WES) offers the opportunity for rapid diagnosis in many paediatric haematological conditions, where phenotypes are variable and either a large number of genes are involved, or the genes are large making sanger sequencing expensive and labour-intensive. NGS offers the potential for gene discovery in patients who do not have mutations in currently known genes. This report shows how WES was used in the diagnosis of six paediatric haematology cases. In four cases (Diamond-Blackfan anaemia, congenital neutropenia (n = 2), and Fanconi anaemia), the diagnosis was suspected based on classical phenotype, and NGS confirmed those suspicions. Mutations in RPS19, ELANE and FANCD2 were found. The final two cases (MYH9 associated macrothrombocytopenia associated with multiple congenital anomalies; atypical juvenile myelomonocytic leukaemia associated with a KRAS mutation) highlight the utility of NGS where the diagnosis is less certain, or where there is an unusual phenotype. We discuss the advantages and limitations of NGS in the setting of these cases, and in haematological conditions more broadly, and discuss where NGS is most efficiently used. PMID:25703294

  5. Effect of ellagic acid on some haematological, immunological and antioxidant parameters of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Mişe Yonar, S; Yonar, M E; Yöntürk, Y; Pala, A

    2014-10-01

    In this study, effect of ellagic acid on some haematological, immunological and antioxidant parameters in the blood and various tissues of rainbow trout (Oncorhynchus mykiss) were examined. Four groups of rainbow trout were fed experimental diets containing either no ellagic acid (control) or supplemented with ellagic acid at 50 mg/kg diet (EA-50), 100 mg/kg diet (EA-100) or 150 mg/kg diet (EA-150) for 21 days. Samples of the blood and tissue (liver, kidney and spleen) were collected at the end of the experiment and analysed for their haematological profile (the red blood cell count, the haemoglobin concentration and the haematocrit level), immune response (the white blood cell count, the oxidative radical production (NBT activity), the total plasma protein and total immunoglobulin level) and oxidant/antioxidant status (the malondialdehyde level, the superoxide dismutase, catalase and glutathione peroxidase activity as well as the reduced glutathione concentration). The findings of this study demonstrated that ellagic acid had a positive effect on the haematological parameters, the immune response and the antioxidant enzyme activities of the fish. PMID:24401136

  6. Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport.

    PubMed

    Bonne, Thomas Christian; Lundby, Carsten; Lundby, Anne Kristine; Sander, Mikael; Bejder, Jacob; Nordsborg, Nikolai Baastrup

    2015-08-01

    The impact of altitude training on haematological parameters and the Athlete Biological Passport (ABP) was evaluated in international-level elite athletes. One group of swimmers lived high and trained high (LHTH, n = 10) for three to four weeks at 2130 m or higher whereas a control group (n = 10) completed a three-week training camp at sea-level. Haematological parameters were determined weekly three times before and four times after the training camps. ABP thresholds for haemoglobin concentration ([Hb]), reticulocyte percentage (RET%), OFF score and the abnormal blood profile score (ABPS) were calculated using the Bayesian model. After altitude training, six swimmers exceeded the 99% ABP thresholds: two swimmers exceeded the OFF score thresholds at day +7; one swimmer exceeded the OFF score threshold at day +28; one swimmer exceeded the threshold for RET% at day +14; and one swimmer surpassed the ABPS threshold at day +14. In the control group, no values exceeded the individual ABP reference range. In conclusion, LHTH induces haematological changes in Olympic-level elite athletes which can exceed the individually generated references in the ABP. Training at altitude should be considered a confounding factor for ABP interpretation for up to four weeks after altitude exposure but does not consistently cause abnormal values in the ABP. PMID:25545030

  7. Fertility preservation in patients with haematological disorders: a retrospective cohort study.

    PubMed

    Senapati, Suneeta; Morse, Christopher B; Sammel, Mary D; Kim, Jayeon; Mersereau, Jennifer E; Efymow, Brenda; Gracia, Clarisa R

    2014-01-01

    This study investigated the factors associated with utilization of fertility preservation and the differences in treatments and outcomes by prior chemotherapy exposure in patients with haematological diseases. This study included all 67 women with haematological diseases seen for fertility preservation consultation at two university hospitals between 2006 and 2011. Of the total, 49% had lymphoma, 33% had leukaemia, 7% had myelodysplastic syndrome and 4% had aplastic anaemia; 46% had prior chemotherapy; and 33% were planning for bone marrow transplantation, 33% pursued ovarian stimulation and 7% used ovarian tissue banking; and 48% of patients did not pursue fertility preservation treatment. All five cycle cancellations were in the post-chemotherapy group: three patients with leukaemia and two with lymphoma. Patients with prior chemotherapy had lower baseline antral follicle count (10 versus 22) and received more gonadotrophins to achieve similar peak oestradiol concentrations, with no difference in oocyte yield (10.5 versus 10) after adjustment for age. Embryo yield was similar between those who had prior chemotherapy and those who had not. Half of the patients with haematological diseases who present for fertility preservation have been exposed to chemotherapy. While ovarian reserve is likely impaired in this group, oocyte yield may be acceptable. PMID:24140311

  8. Haematological and Biochemical Parameters during the Laying Period in Common Pheasant Hens Housed in Enhanced Cages

    PubMed Central

    Hrabčáková, Petra; Voslářová, Eva; Bedáňová, Iveta; Pištěková, Vladimíra; Chloupek, Jan; Večerek, Vladimír

    2014-01-01

    The development of selected haematological and biochemical parameters during the laying period was monitored in common pheasant hens housed in an enhanced cage system. The cages were enhanced by the addition of two perches and a shelter formed by strips of cloth hanging in the corner of the cage. The results showed significant changes in the haematological and biochemical parameters monitored during egg laying. At the time when laying capacity approached a maximum, a decrease was observed (P < 0.05) in haematocrit, erythrocytes, and haemoglobin values, whereas monocytes, eosinophils, the heterophil/lymphocyte ratio, phosphorus, and calcium exhibited an increase (P < 0.05). At the end of the laying period, an increase (P < 0.05) was recorded in the count of leukocytes, heterophils, lymphocytes and basophils, the heterophil to lymphocyte ratio, and the concentrations of aspartate aminotransferase, cholesterol, phosphorus, and calcium, whereas lower values (P < 0.05) were recorded for haematocrit and plasma total protein in comparison with the values of the indicators at the beginning of the laying period. The results provide new information about dynamic changes in selected haematological and biochemical parameters in clinically healthy common pheasant hens during the laying period. PMID:25121117

  9. KIR Genes and Patterns Given by the A Priori Algorithm: Immunity for Haematological Malignancies

    PubMed Central

    Rodríguez-Escobedo, J. Gilberto; García-Sepúlveda, Christian A.; Cuevas-Tello, Juan C.

    2015-01-01

    Killer-cell immunoglobulin-like receptors (KIRs) are membrane proteins expressed by cells of innate and adaptive immunity. The KIR system consists of 17 genes and 614 alleles arranged into different haplotypes. KIR genes modulate susceptibility to haematological malignancies, viral infections, and autoimmune diseases. Molecular epidemiology studies rely on traditional statistical methods to identify associations between KIR genes and disease. We have previously described our results by applying support vector machines to identify associations between KIR genes and disease. However, rules specifying which haplotypes are associated with greater susceptibility to malignancies are lacking. Here we present the results of our investigation into the rules governing haematological malignancy susceptibility. We have studied the different haplotypic combinations of 17 KIR genes in 300 healthy individuals and 43 patients with haematological malignancies (25 with leukaemia and 18 with lymphomas). We compare two machine learning algorithms against traditional statistical analysis and show that the “a priori” algorithm is capable of discovering patterns unrevealed by previous algorithms and statistical approaches. PMID:26495028

  10. Haematological and biochemical parameters during the laying period in common pheasant hens housed in enhanced cages.

    PubMed

    Hrabčáková, Petra; Voslářová, Eva; Bedáňová, Iveta; Pištěková, Vladimíra; Chloupek, Jan; Večerek, Vladimír

    2014-01-01

    The development of selected haematological and biochemical parameters during the laying period was monitored in common pheasant hens housed in an enhanced cage system. The cages were enhanced by the addition of two perches and a shelter formed by strips of cloth hanging in the corner of the cage. The results showed significant changes in the haematological and biochemical parameters monitored during egg laying. At the time when laying capacity approached a maximum, a decrease was observed (P < 0.05) in haematocrit, erythrocytes, and haemoglobin values, whereas monocytes, eosinophils, the heterophil/lymphocyte ratio, phosphorus, and calcium exhibited an increase (P < 0.05). At the end of the laying period, an increase (P < 0.05) was recorded in the count of leukocytes, heterophils, lymphocytes and basophils, the heterophil to lymphocyte ratio, and the concentrations of aspartate aminotransferase, cholesterol, phosphorus, and calcium, whereas lower values (P < 0.05) were recorded for haematocrit and plasma total protein in comparison with the values of the indicators at the beginning of the laying period. The results provide new information about dynamic changes in selected haematological and biochemical parameters in clinically healthy common pheasant hens during the laying period. PMID:25121117

  11. Fertility preservation in patients with haematological disorders: a retrospective cohort study☆

    PubMed Central

    Senapati, Suneeta; Morse, Christopher B; Sammel, Mary D; Kim, Jayeon; Mersereau, Jennifer E; Efymow, Brenda; Gracia, Clarisa R

    2014-01-01

    This study investigated the factors associated with utilization of fertility preservation and the differences in treatments and outcomes by prior chemotherapy exposure in patients with haematological diseases. This study included all 67 women with haematological diseases seen for fertility preservation consultation at two university hospitals between 2006 and 2011. Of the total, 49% had lymphoma, 33% had leukaemia, 7% had myelodysplastic syndrome and 4% had aplastic anaemia; 46% had prior chemotherapy; and 33% were planning for bone marrow transplantation, 33% pursued ovarian stimulation and 7% used ovarian tissue banking; and 48% of patients did not pursue fertility preservation treatment. All five cycle cancellations were in the post-chemotherapy group: three patients with leukaemia and two with lymphoma. Patients with prior chemotherapy had lower baseline antral follicle count (10 versus 22) and received more gonadotrophins to achieve similar peak oestradiol concentrations, with no difference in oocyte yield (10.5 versus 10) after adjustment for age. Embryo yield was similar between those who had prior chemotherapy and those who had not. Half of the patients with haematological diseases who present for fertility preservation have been exposed to chemotherapy. While ovarian reserve is likely impaired in this group, oocyte yield may be acceptable. PMID:24140311

  12. Establishment of baseline haematology and biochemistry parameters in wild adult African penguins (Spheniscus demersus).

    PubMed

    Parsons, Nola J; Schaefer, Adam M; van der Spuy, Stephen D; Gous, Tertius A

    2015-01-01

    There are few publications on the clinical haematology and biochemistry of African penguins (Spheniscus demersus) and these are based on captive populations. Baseline haematology and serum biochemistry parameters were analysed from 108 blood samples from wild, adult African penguins. Samples were collected from the breeding range of the African penguin in South Africa and the results were compared between breeding region and sex. The haematological parameters that were measured were: haematocrit, haemoglobin, red cell count and white cell count. The biochemical parameters that were measured were: sodium, potassium, chloride, calcium, inorganic phosphate, creatinine, cholesterol, serum glucose, uric acid, bile acid, total serum protein, albumin, aspartate transaminase and creatine kinase. All samples were serologically negative for selected avian diseases and no blood parasites were detected. No haemolysis was present in any of the analysed samples. Male African penguins were larger and heavier than females, with higher haematocrit, haemoglobin and red cell count values, but lower calcium and phosphate values. African penguins in the Eastern Cape were heavier than those in the Western Cape, with lower white cell count and globulin values and a higher albumin/globulin ratio, possibly indicating that birds are in a poorer condition in the Western Cape. Results were also compared between multiple penguin species and with African penguins in captivity. These values for healthy, wild, adult penguins can be used for future health and disease assessments. PMID:26016391

  13. Anisotropy and Temperature Dependence of Myoglobin Translational Diffusion in Myocardium: Implication for Oxygen Transport and Cellular Architecture

    PubMed Central

    Lin, Ping-Chang; Kreutzer, Ulrike; Jue, Thomas

    2007-01-01

    Pulsed field gradient NMR methods have determined the temperature-dependent diffusion of myoglobin (Mb) in perfused rat myocardium. Mb diffuses with an averaged translational diffusion coefficient (DMb) of 4.24–8.37 × 10−7cm2/s from 22°C to 40°C and shows no orientation preference over a root mean-square displacement of 2.5–3.5 μm. The DMb agrees with the value predicted by rotational diffusion measurements. Based on the DMb, the equipoise diffusion PO2, the PO2 in which Mb-facilitated and free O2 diffusion contribute equally to the O2 flux, varies from 2.72 to 0.15 in myocardium and from 7.27 to 4.24 mmHg in skeletal muscle. Given the basal PO2 of ∼10 mmHg, the Mb contribution to O2 transport appears insignificant in myocardium. In skeletal muscle, Mb-facilitated diffusion begins to contribute significantly only when the PO2 approaches the P50. In marine mammals, the high Mb concentration confers a predominant role for Mb in intracellular O2 transport under all physiological conditions. The Q10 of the DMb ranges from 1.3 to 1.6. The Mb diffusion data indicate that the postulated gel network in the cell must have a minimum percolation cutoff size exceeding 17.5 Å and does not impose tortuosity within the diffusion root mean-square displacement. Moreover, the similar Q10 for the DMb of solution versus cell Mb suggests that any temperature-dependent alteration of the postulated cell matrix does not significantly affect protein mobility. PMID:17218454

  14. Investigation of Transport Anomalies in LANTHANUM(1-Y) STRONTIUM(Y)CHROMIUM(1-X)MANGANESE(X)OXYGEN(3)

    NASA Astrophysics Data System (ADS)

    Raffaelle, Ryne Patrick

    1990-08-01

    This dissertation presents an investigation of several anomalies associated with electronic transport in the La_{1-y}Sr_{y}Cr_{1-x}Mn_{x} O_3 series. The specific anomaly which prompted this study was a large decrease in electrical conductivity when small amounts of Mn were substituted for Cr in LaCrO _3. This decrease was followed by a sharp rise in the conductivity as the Mn content is increased. This conductivity minimum was unexpected due to the fact that LaMnO_3 was believed to have the same conduction mechanism (small polarons) and nearly the same activation energy as LaCrO_3, but a larger conductivity. A detailed set of electrical conductivity measurements was performed on the LaCr_{1-x}Mn_{x} O_3 series. The conductivity minimum has been attributed to an energy difference between polarons located on Cr or Mn ions as a result of this study. A crossover from multiple-trapping to percolation among energetically lower Mn sites qualitatively explained the conductivity of the LaCr_{1-x}Mn _{x}O _3 series. This explanation combined aspects from traditionally separate models of disordered electronic transport. Thermopower measurements were performed on the LaCr_{1-x}Mn _{x}O _3 series and a similar series in which 10 mol% Sr was substituted for La to investigate the crossover dependence on the carrier concentration. The concentration of small polarons in the Mn end members is much larger than was expected from naturally occurring structural defects. The expected increase in carrier concentration with Sr substitution was suppressed in nearly all Mn containing samples. This work was concluded by suggesting a possible Mn ^{+2}-Mn^{+4 } electronic structure which seems to resolve these problems.

  15. Oxygen Therapy

    MedlinePlus

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  16. Influence of trypanocidal therapy on the haematology of vervet monkeys experimentally infected with Trypanosoma brucei rhodesiense.

    PubMed

    Ngotho, Maina; Kagira, John M; Kariuki, Christopher; Maina, Naomi; Thuita, John K; Mwangangi, David M; Farah, Idle O; Hau, Jann

    2011-07-01

    The aim of this study was to characterise the sequential haematological changes in vervet monkeys infected with Trypanosoma brucei rhodesiense and subsequently treated with sub-curative diminazene aceturate (DA) and curative melarsoprol (MelB) trypanocidal drugs. Fourteen vervet monkeys, on a serial timed-kill pathogenesis study, were infected intravenously with 10(4) trypanosomes of a stabilate T. b. rhodesiense KETRI 2537. They were treated with DA at 28 days post infection (dpi) and with MelB following relapse of infection at 140 dpi. Blood samples were obtained from the monkeys weekly, and haematology conducted using a haematological analyser. All the monkeys developed a disease associated with macrocytic hypochromic anaemia characterised by a reduction in erythrocytes (RBC), haemoglobin (HB), haematocrit (HCT), mean cell volume (MCV), platelet count (PLT), and an increase in the red cell distribution width (RDW) and mean platelet volume (MPV). The clinical disease was characteristic of human African trypanosomiasis (HAT) with a pre-patent period of 3 days. Treatment with DA cleared trypanosomes from both the blood and cerebrospinal fluid (CSF). The parasites relapsed first in the CSF and later in the blood. This treatment normalised the RBC, HCT, HB, PLT, MCV, and MPV achieving the pre-infection values within two weeks while RDW took up to 6 weeks to attain pre-infection levels after treatment. Most of the parameters were later characterised by fluctuations, and declined at one to two weeks before relapse of trypanosomes in the haemolymphatic circulation. Following MelB treatment at 140 dpi, most values recovered within two weeks and stabilised at pre-infection levels, during the 223 days post treatment monitoring period. It is concluded that DA and MelB treatments cause similar normalising changes in the haematological profiles of monkeys infected with T. b. rhodesiense, indicating the efficacy of the drugs. The infection related changes in haematology

  17. The Hyperaccumulator Alyssum murale uses Complexation with Nitrogen and Oxygen Donor Ligands for Ni Transport and Storage

    SciTech Connect

    McNear, Jr., D.; Chanay, R; Sparks, D

    2010-01-01

    The Kotodesh genotype of the nickel (Ni) hyperaccumulator Alyssum murale was examined to determine the compartmentalization and internal speciation of Ni, and other elements, in an effort to ascertain the mechanism used by this plant to tolerate extremely high shoot (stem and leaf) Ni concentrations. Plants were grown either hydroponically or in Ni enriched soils from an area surrounding an historic Ni refinery in Port Colborne, Ontario, Canada. Electron probe micro-analysis (EPMA) and synchrotron based micro X-ray fluorescence ({mu}-SXRF) spectroscopy were used to determine the metal distribution and co-localization and synchrotron X-ray and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopies were used to determine the Ni speciation in plant parts and extracted sap. Nickel is concentrated in the dermal leaf and stem tissues of A. murale bound primarily to malate along with other low molecular weight organic ligands and possibly counter anions (e.g., sulfate). Ni is present in the plant sap and vasculature bound to histidine, malate and other low molecular weight compounds. The data presented herein supports a model in which Ni is transported from the roots to the shoots complexed with histidine and stored within the plant leaf dermal tissues complexed with malate, and other low molecular weight organic acids or counter-ions.

  18. Effect of glutaphen on generation of active oxygen species, photosynthetic electron transport, and the functional activity of photosystem 2 in Chlorella cells

    NASA Astrophysics Data System (ADS)

    Samovich, T. V.; Pshibytko, N. L.; Averina, N. G.

    2006-11-01

    Treatment of chlorella green algae (Chlorella sp.) for 2 h in the dark with the photodynamic herbicide glutaphen (GTP), consisting of 0.3 mM 1,10-phenanthroline and 0.6 mM glutamic acid, followed by illumination leads to efficient generation of active oxygen species (AOS). After 15 min of illumination, AOS accumulation reaches 200% compared with the level in cells of the control culture, then it decreases down to 130% and 115% after 1 day and 3 days of illumination. During the first few days after treatment, we observe inhibition of synthesis of a specific precursor of chlorophyll (Chl): 5-aminolevulinic acid molecules, and then we observe stimulation of the synthesis. The effect of GTP on the photosynthetic activity of chlorella does not depend on the AOS level but rather remains uniform, in contrast to its effect on the Chl biosynthesis system. GTP does not change the efficiency of light harvesting and charge separation at the reaction centers of photosystem (PS) 2, but significantly lowers the functional efficiency of the electron transport chain: the photochemical quenching constants for Chl a fluorescence and the effective quantum yield of photochemical reactions in photosystem 2 decrease. The major mechanism of action for GTP is probably displacement of the secondary quinone acceptor QB from its binding site on the D1 protein by the 1,10-phenanthroline, consequent inhibition of electron efflux from Q{A/-} and increase in the fraction of QB-nonreducing centers of PS 2. The active oxygen species generated in the cells have a photodegradative effect on the Chl biosynthesis system, in particular on its initial steps, and do not involve already formed pigment-protein complexes of PS 2.

  19. DEVELOPMENT OF REACTION-DRIVEN IONIC TRANSPORT MEMBRANES (ITMs) TECHNOLOGY: PHASE IV/BUDGET PERIOD 6 “Development of ITM Oxygen Technology for Integration in IGCC and Other Advanced Power Generation Systems”

    SciTech Connect

    David, Studer

    2012-03-01

    Air Products and Chemicals, along with development participants and in association with the U.S. Department of Energy, has made substantial progress in developing a novel air separation technology. Unlike conventional cryogenic processes, this method uses high-temperature ceramic membranes to produce high-purity oxygen. The membranes selectively transport oxygen ions with high flux and infinite theoretical selectivity. Reaction-driven ceramic membranes are fabricated from non-porous, multi-component metallic oxides, operate at temperatures typically over 700°C, and have exceptionally high oxygen flux and selectivity. Oxygen from low-pressure air permeates as oxygen ions through the ceramic membrane and is consumed through chemical reactions, thus creating a chemical driving force that pulls oxygen ions across the membrane at high rates. The oxygen reacts with a hydrocarbon fuel in a partial oxidation process to produce a hydrogen and carbon monoxide mixture – synthesis gas. This project expands the partial-oxidation scope of ITM technology beyond natural gas feed and investigates the potential for ITM reaction-driven technology to be used in conjunction with gasification and pyrolysis technologies to provide more economical routes for producing hydrogen and synthesis gas. This report presents an overview of the ITM reaction-driven development effort, including ceramic materials development, fabrication and testing of small-scale ceramic modules, ceramic modeling, and the investigation of gasifier integration schemes

  20. Decoupling of the processes of molecular oxygen synthesis and electron transport in Ca2+-depleted PSII membranes.

    PubMed

    Semin, Boris K; Davletshina, Lira N; Ivanov, Il'ya I; Rubin, Andrei B; Seibert, Michael

    2008-01-01

    Extraction of Ca(2+) from the O(2)-evolving complex (OEC) of photosystem II (PSII) membranes with 2 M NaCl in the light (PSII(-Ca/NaCl)) results in 90% inhibition of the O(2)-evolution reaction. However, electron transfer from the donor to acceptor side of PSII, measured as the reduction of the exogenous acceptor 2,6-dichlorophenolindophenol (DCIP) under continuous light, is inhibited by only 30%. Thus, calcium extraction from the OEC inhibits the synthesis of molecular O(2) but not the oxidation of a substrate we term X, the source of electrons for DCIP reduction. The presence of electron transfer across PSII(-Ca/NaCl) membranes was demonstrated using fluorescence induction kinetics, a method that does not require an artificial acceptor. The calcium chelator, EGTA (5 mM), when added to PSII(-Ca/NaCl) membranes, does not affect the inhibition of O(2) evolution by NaCl but does inhibit DCIP reduction up to 92% (the reason why electron transport in Ca(2+)-depleted materials has not been noticed before). Another chelator, sodium citrate (citrate/low pH method of calcium extraction), also inhibits both O(2) evolution and DCIP reduction. The role of all buffer components (including bicarbonate and sucrose) as possible sources of electrons for PSII(-Ca/NaCl) membranes was investigated, but only the absence of chloride anions strongly inhibited the rate of DCIP reduction. Substitution of other anions for chloride indicates that Cl(-) serves its well-known role as an OEC cofactor, but it is not substrate X. Multiple turnover flash experiments have shown a period of four oscillations of the fluorescence yield (both the maximum level, F(max), and the fluorescence level measured 50 s after an actinic flash in the presence of DCMU) in native PSII membranes, reflecting the normal function of the OEC, but the absence of oscillations in PSII(-Ca/NaCl) samples. Thus, PSII(-Ca/NaCl) samples do not evolve O(2) but do transfer electrons from the donor to acceptor sides and exhibit a

  1. Decoupling of the Processes of Molecular Oxygen Synthesis and Electron Transport in Ca2+-Depleted PSII Membranes

    SciTech Connect

    Semin, B. K.; Davletshina, L. N.; Ivanov, I. I.; Rubin, A. B.; Seibert, M.

    2008-10-01

    Extraction of Ca{sup 2+} from the O{sub 2}-evolving complex (OEC) of photosystem II (PSII) membranes with 2 M NaCl in the light (PSII(-Ca/NaCl)) results in 90% inhibition of the O{sub 2}-evolution reaction. However, electron transfer from the donor to acceptor side of PSII, measured as the reduction of the exogenous acceptor 2,6-dichlorophenolindophenol (DCIP) under continuous light, is inhibited by only 30%. Thus, calcium extraction from the OEC inhibits the synthesis of molecular O{sub 2} but not the oxidation of a substrate we term X, the source of electrons for DCIP reduction. The presence of electron transfer across PSII(-Ca/NaCl) membranes was demonstrated using fluorescence induction kinetics, a method that does not require an artificial acceptor. The calcium chelator, EGTA (5 mM), when added to PSII(-Ca/NaCl) membranes, does not affect the inhibition of O{sub 2} evolution by NaCl but does inhibit DCIP reduction up to 92% (the reason why electron transport in Ca{sup 2+}-depleted materials has not been noticed before). Another chelator, sodium citrate (citrate/low pH method of calcium extraction), also inhibits both O{sub 2} evolution and DCIP reduction. The role of all buffer components (including bicarbonate and sucrose) as possible sources of electrons for PSII(-Ca/NaCl) membranes was investigated, but only the absence of chloride anions strongly inhibited the rate of DCIP reduction. Substitution of other anions for chloride indicates that Cl{sup -} serves its well-known role as an OEC cofactor, but it is not substrate X. Multiple turnover flash experiments have shown a period of four oscillations of the fluorescence yield (both the maximum level, F{sub max}, and the fluorescence level measured 50 s after an actinic flash in the presence of DCMU) in native PSII membranes, reflecting the normal function of the OEC, but the absence of oscillations in PSII(-Ca/NaCl) samples. Thus, PSII(-Ca/NaCl) samples do not evolve O{sub 2} but do transfer electrons from

  2. Isolated quadriceps training increases maximal exercise capacity in chronic heart failure: The role of skeletal muscle convective and diffusive oxygen transport

    PubMed Central

    Esposito, Fabio; Reese, Van; Shabetai, Ralph; Wagner, Peter D.; Richardson, Russell S.

    2011-01-01

    Objectives This study sought to elucidate the mechanisms responsible for the benefits of small muscle mass exercise training in patients with chronic heart failure (CHF). Background How central cardiorespiratory and/or peripheral skeletal muscle factors are altered with small muscle mass training in CHF is unknown. Methods We studied muscle structure and oxygen (O2) transport and metabolism at maximal cycle (whole body) and knee-extensor exercise (KE) (small muscle mass) in 6 healthy controls and 6 patients with CHF who then performed 8 weeks of KE training (both legs, separately) and repeated these assessments. Results Pre-training cycling and KE peak leg O2 uptake (VO2peak) were ~17% and ~15% lower, respectively, in the patients compared to controls. Structurally, KE training increased quadriceps muscle capillarity and mitochondrial density by ~21 and ~25%, respectively. Functionally, despite not altering maximal cardiac output, KE training increased maximal O2 delivery (~54%), arterial-venous O2 (a–v O2) difference (~10%), and muscle O2 diffusive conductance (DMO2) (~39%) (assessed during KE), thereby increasing single leg VO2peak by ~53%, to a level exceeding that of the untrained controls. Post-training, during maximal cycling, O2 delivery (~40%), a–v O2 difference (~15%), and DMO2 (~52%) all increased, yielding an increase in VO2peak of ~40%, matching the controls. Conclusions In the face of continued central limitations, clear improvements in muscle structure, peripheral convective and diffusive O2 transport, and subsequently O2 utilization support the efficacy of local skeletal muscle training as a powerful approach to combat exercise intolerance in CHF. PMID:21920265

  3. Haematological malignancies: the rationale for integrated haematopathology services, key elements of organization and wider contribution to patient care.

    PubMed

    Ireland, Robin

    2011-01-01

    The National Institute for Clinical Excellence (NICE) defined the process of care for haematological malignancies in Improving outcomes in haematological cancers. The manual in 2003. The most challenging recommendation has been the requirement to develop integrated laboratory services for accurate diagnosis. This is an aim that has not been fully achieved. The unified concept of haematological malignancy is recent and based on an understanding of the cellular pathology of the bone marrow and immune systems. Historical UK pathology practice has previously resulted in the separation of laboratory haematology from histopathology and of liquid and tissue specimens. Proposals for reintegration and centralization with specialist-led, centralized diagnostic and reporting services challenge the fragmented historical model. Accuracy and certainty of diagnosis remains problematic, particularly for lymphomas, with evidence that the accuracy of diagnosis is slowly improving but still only approaches 85%. There is a potentially significant human and financial cost of diagnostic errors. No nationwide, validated and comparable epidemiology/population-based data exist for accurate and complete ascertainment of new cases of haematological cancer, service planning or clinical outcomes monitoring. This article examines the original rationale behind the NICE guidance and outlines the key components and processes of an integrated diagnostic service. PMID:21261689

  4. Destined to die in hospital? Systematic review and meta-analysis of place of death in haematological malignancy

    PubMed Central

    2010-01-01

    Background Haematological malignancies are a common, heterogeneous and complex group of diseases that are often associated with poor outcomes despite intensive treatment. Research surrounding end-of-life issues, and particularly place of death, is therefore of paramount importance, yet place of death has not been formally reviewed in these patients. Methods A systematic literature review and meta-analysis was undertaken using PubMed to identify all studies published between 1966 and 2010. Studies examining place of death in adult haematology patients, using routinely compiled morbidity and mortality data and providing results specific to this disease were included. 21 studies were identified with descriptive and/or risk-estimate data; 17 were included in a meta-analysis. Results Compared to other cancer deaths, haematology patients were more than twice as likely to die in hospital (Odds Ratio 2.25 [95% Confidence Intervals, 2.07-2.44]). Conclusion Home is generally considered the preferred place of death but haematology patients usually die in hospital. This has implications for patients who may not be dying where they wish, and also health commissioners who may be funding costly end-of-life care in inappropriate acute hospital settings. More research is needed about preferred place of care for haematology patients, reasons for hospital deaths, and how these can be avoided if home death is preferred. PMID:20515452

  5. Oxygen in demand: How oxygen has shaped vertebrate physiology.

    PubMed

    Dzal, Yvonne A; Jenkin, Sarah E M; Lague, Sabine L; Reichert, Michelle N; York, Julia M; Pamenter, Matthew E

    2015-08-01

    In response to varying environmental and physiological challenges, vertebrates have evolved complex and often overlapping systems. These systems detect changes in environmental oxygen availability and respond by increasing oxygen supply to the tissues and/or by decreasing oxygen demand at the cellular level. This suite of responses is termed the oxygen transport cascade and is comprised of several components. These components include 1) chemosensory detectors that sense changes in oxygen, carbon dioxide, and pH in the blood, and initiate changes in 2) ventilation and 3) cardiac work, thereby altering the rate of oxygen delivery to, and carbon dioxide clearance from, the tissues. In addition, changes in 4) cellular and systemic metabolism alters tissue-level metabolic demand. Thus the need for oxygen can be managed locally when increasing oxygen supply is not sufficient or possible. Together, these mechanisms provide a spectrum of responses that facilitate the maintenance of systemic oxygen homeostasis in the face of environmental hypoxia or physiological oxygen depletion (i.e. due to exercise or disease). Bill Milsom has dedicated his career to the study of these responses across phylogenies, repeatedly demonstrating the power of applying the comparative approach to physiological questions. The focus of this review is to discuss the anatomy, signalling pathways, and mechanics of each step of the oxygen transport cascade from the perspective of a Milsomite. That is, by taking into account the developmental, physiological, and evolutionary components of questions related to oxygen transport. We also highlight examples of some of the remarkable species that have captured Bill's attention through their unique adaptations in multiple components of the oxygen transport cascade, which allow them to achieve astounding physiological feats. Bill's research examining the oxygen transport cascade has provided important insight and leadership to the study of the diverse suite

  6. The effect of oxygen content on the magnetic and transport properties of FeSr2Y1.5Ce0.5Cu2O8+x

    NASA Astrophysics Data System (ADS)

    Sambale, Sebastian; Williams, Grant V. M.; Chong, Shen V.

    2016-04-01

    The magnetic and transport properties of FeSr2Y1.5Ce0.5Cu2O8+x have been studied in the oxygen saturated (OS) and oxygen reduced (OR) states. We find that the low temperature spin-glass transition is not affected by the oxygen content in the SrFeO3-x subunit although the magnitude of the Curie-Weiss temperature is significantly larger in the OR sample. The oxygen reduced sample also has an antiferromagnetic transition at ~310 K that is likely to be due to antiferromagnetic ordering of the Cu moments in the CuO2 plane. The resistivity from the OR sample can be modeled in terms of variable range hopping and activated conduction, which indicates that it is a very disordered semiconductor. The oxygen saturated sample has additional holes in the CuO2 plane and the absence of superconductivity is likely due to pair breaking from Fe on the Cu sites in the CuO2 plane. We modeled the resistivity in the OS state in terms of inhomogeneous transport where there are metallic regions and disordered regions that have a resistivity with a 1/Tm temperature dependence at low temperatures.

  7. Absence of ocular manifestations in autosomal dominant Alport syndrome associated with haematological abnormalties.

    PubMed

    Colville, D; Wang, Y Y; Jamieson, R; Collins, F; Hood, J; Savige, J

    2000-12-01

    Most patients with Alport syndrome have X-linked or autosomal recessive disease that is characterised by renal failure, hearing loss, and, in nearly 75% of the cases, a dot-and-fleck retinopathy and anterior lenticonus. There are only case reports of individuals with the rare autosomal dominant form, who can have haematuria or renal failure, deafness, and, in addition, low platelet counts and neutrophil inclusions. The ocular features of autosomal dominant inheritance have not been described. We have examined the eyes in the members of two families where Alport syndrome was diagnosed on the basis of the clinical features and family history, and where autosomal dominant inheritance was confirmed by father-to-son disease transmission, the associated haematological abnormalities, and haplotypes that segregated with the recently described locus at chromosome 22q. In Family A, the eyes of two individuals with haematuria, hearing loss, and haematological abnormalities and of nine unaffected family members were examined. In Family B, the eyes of two individuals with renal failure, normal hearing, and haematological abnormalities were examined. None of the affected or unaffected members in either family had a dot-and-fleck retinopathy, anterior lenticonus, a history suggesting recurrent corneal erosions, or corneal dystrophy. These results indicate that the protein abnormality in autosomal dominant Alport syndrome does not produce the retinopathy and lenticonus typical of X-linked and autosomal recessive disease. This may be because the abnormal protein is not present or is less important in the ocular basement membranes than elsewhere, or because the presence of a normal allele in autosomal dominant disease compensates for the defective allele. PMID:11135492

  8. Infection by Brazilian and Dutch swine hepatitis E virus strains induces haematological changes in Macaca fascicularis

    PubMed Central

    2013-01-01

    Background Hepatitis E virus (HEV) has been described as an emerging pathogen in Brazil and seems to be widely disseminated among swine herds. An autochthonous human case of acute hepatitis E was recently reported. To obtain a better understanding of the phenotypic profiles of both human and swine HEV strains, a experimental study was conducted using the animal model, Macaca fascicularis. Methods Six cynomolgus monkeys (Macaca fascicularis) were inoculated intravenously with swine HEV genotype 3 that was isolated from naturally and experimentally infected pigs in Brazil and the Netherlands. Two other monkeys were inoculated with HEV genotype 3 that was recovered from Brazilian and Argentinean patients with locally acquired acute and fulminant hepatitis E. The haematological, biochemical, and virological parameters of all animals were monitored for 67 days. Results Subclinical hepatitis was observed in all monkeys after inoculation with HEV genotype 3 that was recovered from the infected swine and human patients. HEV RNA was detected in the serum and/or faeces of 6 out of the 8 cynomolgus monkeys between 5 and 53 days after inoculation. The mild inflammation of liver tissues and elevations of discrete liver enzymes were observed. Seroconversions to anti-HEV IgM and/or IgG were detected in 7 animals. Reactivities to anti-HEV IgA were also detected in the salivary samples of 3 animals. Interestingly, all of the infected monkeys showed severe lymphopenia and a trend toward monocytosis, which coincided with elevations in alanine aminotransferase and antibody titres. Conclusions The ability of HEV to cross the species barrier was confirmed for both the swine (Brazilian and Dutch) and human (Argentinean) strains, thus reinforcing the zoonotic risk of hepatitis E in South America. Cynomolgus monkeys that were infected with HEV genotype 3 developed subclinical hepatitis that was associated with haematological changes. Haematological approaches should be considered in

  9. Systemic mastocytosis with associated clonal haematological non-mast cell lineage diseases: a histopathological challenge

    PubMed Central

    Horny, H-P; Sotlar, K; Sperr, W R; Valent, P

    2004-01-01

    Aims: Although systemic mastocytosis (SM) with an associated clonal haematological non-mast cell lineage disease (SM-AHNMD) is a major subtype of SM, little is known about its frequency among myelogenous neoplasms, and mastocytosis in particular, or about AHNMD subtype frequencies. Methods: Approximately 19 500 routine bone marrow biopsies were evaluated. Immunostaining with antibodies against tryptase, KIT, and CD25 and molecular analysis for detection of C-KIT point mutations were performed in approximately 550/4100 myelogenous malignancies including mastocytosis, almost all subtypes of myelodysplastic syndrome (MDS), myelodysplastic/myeloproliferative syndrome (MDS/MPD), MPD, and acute myeloid leukaemia (AML). Results: SM was rare—it was diagnosed in only 64 bone marrows (0.3%) and made up 1.5% of myelogenous tumours. SM-AHNMD was the second most frequent subtype (20). SM-AHNMD was never included in the clinical differential diagnoses and was confirmed histologically in most cases only after appropriate immunostaining. The abnormal mast cell phenotype was confirmed by immunohistochemical demonstration of tryptase and CD25 coexpression. The following associated haematological neoplasms were found: MDS/MPS, AML, MPS, MDS, plasma cell myeloma, and unclassifiable myelogenous malignancy. C-KIT point mutations were detected in 16 of 20 cases. Conclusions: SM-AHNMD can be diagnosed histologically in bone marrow trephines only after immunostaining with antibodies against tryptase, KIT, and CD25. Eighteen of 20 AHNMDs were of myeloid origin. C-KIT point mutations were present in 16 of 20 cases. The prognostic relevance of detecting SM associated with another haematological neoplasm remains unclear, but mast cell resistance to most cytoreductive agents is of major importance for treatment planning. PMID:15166264

  10. Haematological response of snow barbell, Schizothorax plagiostomus Heckel, naturally infected with a new Trypanosoma species.

    PubMed

    Maqbool, Aamir; Ahmed, Imtiaz

    2016-09-01

    The present study deals with the description of a new piscine trypanosome species found infecting the fresh water fish Schizothorax plagiostomus Heckel from river Jhelum, Srinagar, J&K, India and evaluating the haematological parameters of the infected fish. Haematological examination of S. plagiostomus revealed 61.1 % infection with an intensity of 1-9 trypanosomes/100 RBC's. Small (26.9 ± 1.39 µm) and large (47.17 ± 3.50 µm) forms of the trypanosome were observed in light microscopy investigations, revealing the dimorphic nature of the species. The trypanosome species was found to be distinct from the other related dimorphic species in morphometric dimensions including cell length, cell breadth, kinetoplast index, flagellar index, and cytological peculiarities, respectively. The detailed descriptions of the two morphological forms found in the blood of S. plagiostomus are provided. Based on the geographical location, morphometrics, cytological peculiarities, host status and comparative study, the new species is named Trypanosoma kashmirensis n. sp. The parasitic infestation caused a significant decrease (p < 0.05) in red blood cell counts, haematocrit and haemoglobin concentrations while, the leucocyte (WBC) count, mean cellular volume and mean cellular haemoglobin showed a significant increase (p < 0.05) in the infected fish as compared to the non-infected. The above alterations of the haematological parameters could be used as an important tool for the indication of Trypanosoma infection in the fish. PMID:27605786

  11. Seasonal changes in haematology, lymphocyte transferrin receptors and intracellular iron in Ironman triathletes and untrained men.

    PubMed

    Broadbent, Suzanne

    2011-01-01

    We investigated whether 12 months of chronic endurance training would affect haematology, CD4(+) lymphocyte transferrin receptor (CD71) expression, CD4(+) intracellular iron and the incidence of upper respiratory tract illnesses (URTI) in Ironman triathletes compared with untrained men. Resting venous blood samples were taken from 15 Ironman triathletes (TR 30 ± 5 year) and 12 untrained men (UT 30 ± 6 year) every 4 weeks for 12 months. Erythrocyte, leukocyte and platelet concentration, haematocrit, haemoglobin (Hb) and mean corpuscular haemoglobin (MCHC) were measured with a full blood count. CD4(+) lymphocytes were analysed for changes in transferrin receptor (CD71) expression (CD4(+)CD71(+)), and intracellular iron (Fe(3+)), by flow cytometry. The TR group had significantly lower Hb, MCHC, and platelets for 10, 9 and 11 months, respectively; lower CD4(+)CD71(+) (3 months) and Fe(3+) (1 month), respectively; higher CD4(+)CD71(+) (1 month); a higher lymphocyte count for 4 months. There were no between-group differences in other variables. In both groups haematology and lymphocytes increased during spring, early summer and winter and decreased during late summer/late winter, with an inverse relationship between CD4(+)CD71(+) and Fe(3+). The TR group reported significantly fewer URTI than the UT. Low Hb and MCHC suggest an iron deficiency which may affect triathlete performance. Monthly changes in lymphocytes, CD4(+)CD71(+) and Fe(3+) suggested that spring, summer and late autumn are associated with CD4(+) proliferation. There may be seasonal relationships between haematology and lymphocyte function, independent of endurance training, possibly affecting performance but not the incidence of URTI. PMID:20821024

  12. The value of haematological screening for AIDS in an at risk population.

    PubMed Central

    Weber, J N; Walker, D; Engelkins, H; Bain, B; Harris, J R

    1985-01-01

    The haematological variables measured by automated full blood count in matched homosexual and heterosexual men attending a clinic for sexually transmitted diseases (STD) were compared with those of normal controls and patients infected with the human T lymphotropic virus type III (HTLV-III). Homosexual and heterosexual men were statistically identical for all variables, but both differed noticeably from patients with clinical diagnoses of the acquired immune deficiency syndrome (AIDS) or AIDS related disease. A full blood count as a screening test for AIDS is only interpretable in the context of clinical assessment. PMID:2995238

  13. Sex-related differences in the haematological effects of excessive alcohol consumption.

    PubMed Central

    Chalmers, D M; Chanarin, I; Macdermott, S; Levi, A J

    1980-01-01

    Mean corpuscular volume (MCV) was measured at presentation in 320 hospital patients with a history of excessive alcohol consumption. The MCV of the 94 women thought to be actively drinking more than 80 g/day of alcohol was 101.3 fl compared with 96.7 fl in their male counterparts. Alcohol consumption, age, smoking habits, prevalence of inadequate diet, or serum and red cell folate levels did not differ significantly between men and women. It is suggested that MCV is a better indicator of excessive alcohol consumption in women than in men, and that women are more susceptible to the haematological toxicity of alcohol. PMID:7358858

  14. A probable role of blood lead levels on some haematological parameters in traffic police, Lahore, Pakistan.

    PubMed

    Khan, Shafaat Yar; Arshad, Muhammad; Arshad, Najma; Shafaat, Shazia; Tahir, Hafiz Muhammad

    2016-05-01

    The impact of elevated blood lead level on some haematological parameters was studied in the field force of Lahore traffic police, in Pakistan. The blood samples were tested for total leucocytes count (TLC) and differential leucocytes count in the persons with high and low blood lead levels. The TLC and percentage of neutrophils and eosinophils were observed as being significantly elevated in the policemen. No significant change was observed in the percentage of lymphocytes, while the percentage of monocytes was observed as being significantly less in the field force of traffic police. PMID:24311624

  15. Changes of haematological indices of grass carp, Ceteopharyngodon idella exposed to monogenean parasites, Gyrodactylus spp. and Dactylogyrus spp.

    PubMed

    Restiannasab, Abulhasan; Hemmatzadeh, Mohtaram; Khara, Hossein; Saljoghi, Zoheir Shokouh

    2016-09-01

    The present was carried out to investigate the effects of monogenean infection on haematological indices of grass carp, Ceteopharyngodon idella. In this regard, some haematological indices were measured in two adult groups of grass carp including healthy and infected fish. According to our results, the values of red blood cells (RBCs), haemoglobin (Hb) decreased significantly in infected fishes (P < 0.05). In contrast, the white blood cells (WBCs) values increased significantly in infected fishes (P < 0.05). In contrast, the WBC values increased significantly in infected fishes. In conclusion, our results showed that monogenean infection by Gyrodactylus spp. and Dactylogyrus spp. can affects health condition of grass carp through alternation of haematology. PMID:27605756

  16. Studies of C-Axis Charge Transport in BISMUTH(2) STRONTIUM(2) Calcium COPPER(2) OXYGEN(8 + Delta) and Anomalous Hall Effect in (LANTHANUM(0.67) CALCIUM(0.33)) Manganese OXYGEN(3)

    NASA Astrophysics Data System (ADS)

    Yi-Feng, Yan

    In this thesis I report my studies on charge transport on two perovskite metal oxides: La_ {1-x}Ca_{x}MnO_3(LCMO) --a colossal magnetoresistance oxide and Bi_2Sr_2CaCu_2O_{8+delta } (BSCCO)--a high temperature superconducting compound. Large and high quality Bi_2Sr _2CaCu_2O_{8+delta} single crystals were grown by self-flux method. The quality of the crystals were examined by x-ray diffraction and electron diffraction. I have systematically investigated the c-axis magnetoresistance (MR) of various BSCCO single crystals with different oxygen contents. With field H parallel to c-axis and the current (H//c//J), we observed that MR is negative if rho_ {c} is semiconducting and positive if rho_{c} is pseudo-metallic. We consider that the negative MR is a normal state property. We have also measured the field dependence of rho_{c} in the flux flow state (H//c//J) at fields up to 14T. Whereas rho_{c} increases rapidly in weak fields, it saturates to the extrapolated normal-state curve when the field H_ {2D} is attained (H_ {2D} is the field at which the vortex pancakes in adjacent layers are completely decoupled). At fields above H_{2D}, rho_{c} decreases slowly. We verify that this is a continuation of the negative MR observed above Tc. We propose that the antiferromagnetic coupling along the c-axis in adjacent CuO_2 planes and spin singlet formation are the cause of negative magnetoresistance in c-axis in bilayer cuprates. We found that the c-axis resistivity in bilayer cuprates can be fitted into the following empirical formula: rho_{c}{= }a/Te^{Delta/T} + cT + d where a, c and d are temperature independent constants; Delta is called pseudogap. In Y -doped BSCCO, rho_{c} displays a logarithmic temperature dependence. The LCMO thin films used in this experiment were grown by Plasma Enhanced-MOCVD method. The Hall effect and magnetoresistance of LCMO thin films have been systematically investigated. At low temperature, the Hall effect is linear with field and positive

  17. Monitoring environmental Aspergillus spp. contamination and meteorological factors in a haematological unit.

    PubMed

    Cavallo, M; Andreoni, S; Martinotti, M G; Rinaldi, M; Fracchia, L

    2013-12-01

    The opportunistic pathogens belonging to the Aspergillus genus are present in almost all seasons of the year, and their concentration is related to meteorological conditions. The high density of Aspergillus spp. conidia in a haematological hospital ward may be a significant risk factor for developing invasive fungal diseases in immunocompromised patients. Aim of the present study was to evaluate the variability of airborne Aspergillus spp. conidia contamination in a Haematological Unit (HU) within a period of 16 months in relation with some meteorological parameters. An environmental Aspergillus surveillance was conducted in the HU in four rooms and their bathrooms, in the corridor and in three external sites using an agar impact sampler. During each sampling, temperature and relative humidity at each site were recorded and current wind speed and rainfall events were taken from the official weather service. Aspergillus spp. conidia concentration differed significantly across the sampling sites. Internal Aspergillus spp. loads were significantly dependent on temperature, internal relative humidity and rain. External conidia concentrations were significantly influenced by outdoor temperature and relative humidity. A suitable indicator was introduced to evaluate the seasonal distribution of Aspergillus spp. conidia in the sampling sites, and a significant dependence on this indicator was observed inside the HU. Seventeen different fungal species belonging to the Aspergillus genus were detected during the sampling period. Aspergillus fumigatus was the most frequently isolated species and its distribution depended significantly on the seasonal indicator both inside and outside the hospital ward. PMID:24158616

  18. An experimental meat-free diet maintained haematological characteristics in sprint-racing sled dogs.

    PubMed

    Brown, Wendy Y; Vanselow, Barbara A; Redman, Andrew J; Pluske, John R

    2009-11-01

    A dog's nutrient requirements can theoretically be met from a properly balanced meat-free diet; however, proof for this is lacking. Exercise places additional demands on the body, and dogs fed a meat-free diet may be at increased risk of developing sports anaemia. We hypothesised that exercising dogs would remain in good health and not develop anaemia when fed a nutritionally balanced meat-free diet. To this end, twelve sprint-racing Siberian huskies were fed either a commercial diet recommended for active dogs (n 6), or a meat-free diet formulated to the same nutrient specifications (n 6). The commercial diet contained 43 % poultry meal, whereas soyabean meal and maize gluten made up 43 % of the meat-free diet, as the main protein ingredients. Dogs were fed these diets as their sole nutrient intake for 16 weeks, including 10 weeks of competitive racing. Blood samples were collected at weeks 0, 3, 8 and 16, and veterinary health checks were conducted at weeks 0, 8 and 16. Haematology results for all dogs, irrespective of diet, were within normal range throughout the study and the consulting veterinarian assessed all dogs to be in excellent physical condition. No dogs in the present study developed anaemia. On the contrary, erythrocyte counts and Hb values increased significantly over time (P < 0.01) in both groups of dogs. The present study is the first to demonstrate that a carefully balanced meat-free diet can maintain normal haematological values in exercising dogs. PMID:19480731

  19. Haematology and plasma chemistry of the red top ice blue mbuna cichlid (Metriaclima greshakei).

    PubMed

    Snellgrove, Donna L; Alexander, Lucille G

    2011-10-01

    Clinical haematology and blood plasma chemistry can be used as a valuable tool to provide substantial diagnostic information for fish. A wide range of parameters can be used to assess nutritional status, digestive function, disease identification, routine metabolic levels, general physiological status and even the assessment and management of wild fish populations. However to evaluate such data accurately, baseline reference intervals for each measurable parameter must be established for the species of fish in question. Baseline data for ornamental fish species are limited, as research is more commonly conducted using commercially cultured fish. Blood samples were collected from sixteen red top ice blue cichlids (Metriaclima greshakei), an ornamental freshwater fish, to describe a range of haematology and plasma chemistry parameters. Since this cichlid is fairly large in comparison with most tropical ornamental fish, two independent blood samples were taken to assess a large range of parameters. No significant differences were noted between sample periods for any parameter. Values obtained for a large number of parameters were similar to those established for other closely related fish species such as tilapia (Oreochromis spp.). In addition to reporting the first set of blood values for M. Greshakei, to our knowledge, this study highlights the possibility of using previously established data for cultured cichlid species in studies with ornamental cichlid fish. PMID:22005416

  20. Bronchoalveolar Lavage Fluid Cellular and Haematological Changes in Different Types of Caprine Pneumonia.

    PubMed

    Jarikre, A T; Emikpe, O B; Ohore, G O; Akinremi, A T; Akpavie, O S

    2016-01-01

    Goats in the tropics are often reared under the traditional extensive and semi-intensive management systems. These and other factors influence the pattern of pneumonia complex in goats. We investigated the bronchoalveolar lavage fluid (BALf) cellular changes and haematological response in different types of caprine pneumonia in Nigeria. Haematological indices and BALf cells were analysed from 300 goats randomly selected from 700 goats comprising different breed, age and body scores. The pneumonia status was well characterised using standard pathological tools. Data is summarized as Mean ± SEM and compared using non-parametric statistics at 5% significance. There was leukocytosis in the pneumonic animals. The overall lavage recovery rate was 55.5%. The differences in Haemoglobin concentration, and Lymphocyte-Neutrophil ratio were significant (p<0.05). BALf changes in the neutrophil, macrophage and eosinophil counts were significantly different (p<0.05). The diagnostic features including increased percentage neutrophils, Macrophage-Neutrophil ratio and eosinophils observed in BAL were reliable and also correlated positively to the pathological findings. BAL should be considered a component of the diagnostic approach to caprine pneumonia complex, as it may accurately aid diagnosis and identification of the causal organisms. PMID:27574761

  1. Clostridium difficile Infections amongst Patients with Haematological Malignancies: A Data Linkage Study

    PubMed Central

    Slimings, Claudia; Joske, David J. L.; Riley, Thomas V.

    2016-01-01

    Objectives Identify risk factors for Clostridium difficile infection (CDI) and assess CDI outcomes among Australian patients with a haematological malignancy. Methods A retrospective cohort study involving all patients admitted to hospitals in Western Australia with a haematological malignancy from July 2011 to June 2012. Hospital admission data were linked with all hospital investigated CDI case data. Potential risk factors were assessed by logistic regression. The risk of death within 60 and 90 days of CDI was assessed by Cox Proportional Hazards regression. Results There were 2085 patients of whom 65 had at least one CDI. Twenty percent of CDI cases were either community-acquired, indeterminate source or had only single-day admissions in the 28 days prior to CDI. Using logistic regression, having acute lymphocytic leukaemia, neutropenia and having had bacterial pneumonia or another bacterial infection were associated with CDI. CDI was associated with an increased risk of death within 60 and 90 days post CDI, but only two deaths had CDI recorded as an antecedent factor. Ribotyping information was available for 33 of the 65 CDIs. There were 19 different ribotypes identified. Conclusions Neutropenia was strongly associated with CDI. While having CDI is a risk factor for death, in many cases it may not be a direct contributor to death but may reflect patients having higher morbidity. A wide variety of C. difficile ribotypes were found and community-acquired infection may be under-estimated in these patients. PMID:27314498

  2. Yoga in addition to standard care for patients with haematological malignancies

    PubMed Central

    Felbel, Steffen; Meerpohl, Joerg J; Monsef, Ina; Engert, Andreas; Skoetz, Nicole

    2016-01-01

    Background Haematological malignancies are malignant neoplasms of the myeloid or lymphatic cell lines including leukaemia, lymphoma and myeloma. In order to manage physical and psychological aspects of the disease and its treatment, complementary therapies like yoga are coming increasingly into focus. However, the effectiveness of yoga practice for people suffering from haematological malignancies remains unclear. Objectives To assess the effects of yoga practice in addition to standard cancer treatment for people with haematological malignancies. Search methods Our search strategy included the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1950 to 4th February 2014), databases of ongoing trials (controlled-trials.com; clinicaltrials.gov), conference proceedings of the American Society of Clinical Oncology, the American Society of Hematology, the European Haematology Association, the European Congress for Integrative Medicine, and Global Advances in Health and Medicine. We handsearched references of these studies from identified trials and relevant review articles. Two review authors independently screened the search results. Selection criteria We included randomised controlled trials (RCTs) of yoga in addition to standard care for haematological malignancies compared with standard care only. We did not restrict this to any specific style of yoga. Data collection and analysis Two review authors independently extracted data for eligible studies and assessed the risk of bias according to predefined criteria. We evaluated distress, fatigue, anxiety, depression and quality of sleep. Further outcomes we planned to assess were health-related quality of life (HRQoL), overall survival (OS) and adverse events (AE), but data on these were not available. Main results Our search strategies led to 149 potentially relevant references, but only a single small study met our inclusion criteria. The included study was published as a full text article and

  3. Functional effect of haemoglobin polymorphism on the haematological pattern of Gentile di Puglia sheep.

    PubMed

    Pieragostini, E; Rubino, G; Bramante, G; Rullo, R; Petazzi, F; Caroli, A

    2006-04-01

    The relationship between haemoglobin polymorphism and haematological pattern were studied in Gentile di Puglia, the Apulia Merino native breed. In a sample of 292 individuals, on five different farms, alpha- and beta-globin genetic polymorphism was investigated. A remarkable polymorphism was detected especially at alpha-globin gene where the variations concerned both the quality of the gene product and gene expression. Triplicated and quadruplicated alpha-globin genes were observed in 8.6% and 1.2% of the alpha-haplotypes respectively. At beta-globin (HBB) locus, predominance of HBB(B) allele was found in all flocks, while HBB(A) overall frequency was around 11.2%. Moreover, the effect of genotypes at globin systems on haematological data was evaluated on 289 animals. A significant effect was detected for HBB locus on haematocrit (HCT) and mean corpuscular volume (MCV), with decreasing HCT and MCV for decreasing number of HBB(A) alleles in the genotype. The opposite trend was observed for mean corpuscular haemoglobin concentration. The advances presented by this paper give reasons for inferring that BB genotypes can be expected to be more resilient to climatic stress and to local parasites. PMID:16533366

  4. Inside the Redbox: applications of haematology in wildlife monitoring and ecosystem health assessment.

    PubMed

    Maceda-Veiga, Alberto; Figuerola, Jordi; Martínez-Silvestre, Albert; Viscor, Ginés; Ferrari, Nicola; Pacheco, Mário

    2015-05-01

    Blood analyses have great potential in studies of ecology, ecotoxicology and veterinary science in wild vertebrates based on advances in human and domestic animal medicine. The major caveat for field researchers, however, is that the 'rules' for human or domestic animal haematology do not always apply to wildlife. The present overview shows the strengths and limitations of blood analyses in wild vertebrates, and proposes a standardisation of pre-analytical procedures plus some suggestions for a more systematic examination of blood smears to increase the diagnostic value of blood data. By discussing the common problems that field researchers face with blood variables, we also aim to highlight common ground enabling new researchers in the field to accurately collect blood samples and interpret and place their haematological findings into the overall picture of an ecological or eco-toxicological study. Besides showing the practicality and ecological relevance of simple blood variables, this study illustrates the suitability of blood samples for the application of cutting-edge analytical procedures for expanding the current repertoire of diagnostic tools in wildlife monitoring and ecosystem health assessment. PMID:25668285

  5. Differences in incidence and trends of haematological malignancies in Japan and the United States.

    PubMed

    Chihara, Dai; Ito, Hidemi; Matsuda, Tomohiro; Shibata, Akiko; Katsumi, Akira; Nakamura, Shigeo; Tomotaka, Sobue; Morton, Lindsay M; Weisenburger, Dennis D; Matsuo, Keitaro

    2014-02-01

    The incidence of a malignant disease reflects the genetic and cumulative exposure to the environment of a population. Therefore, evaluation of the incidence and trends of a disease in different populations may provide insights into its aetiology and pathogenesis. To evaluate the incidence of haematological malignancies according to specific subtypes, we used population-based registry data in Japan (N = 125 148) and the United States (US; N = 172 925) from 1993 to 2008. The age-adjusted incidence of haematological malignancies in Japan was approximately one-half that in the US but has been increasing significantly, whereas no significant change was seen in the US [annual percent change (95% C confidence interval): Japan, +2·4% (1·7, 3·1); US, +0·1% (-0·1, 0·2)]. Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) showed the largest differences in incidence, with the most remarkable differences observed for chronic lymphocytic leukaemia, HL-nodular sclerosis, mycosis fungoides and cutaneous T-cell lymphoma. HL and NHL are increasing substantially in Japan but not in the US, suggesting that environmental exposures, such as Westernization of the life style may be causing this increase. Differences in the incidence and trends for specific subtypes also showed a marked contrast across subtypes, which, in turn, may provide significant new insights into disease aetiology in the future. PMID:24245986

  6. Relationship between anthropometric and haematological parameters among third trimester pregnant women in Sokoto State, Northwest Nigeria.

    PubMed

    Bamaiyi, A J; Adelaiye, A B; Igbokwe, V U

    2013-01-01

    The pregnancy state in a woman's life is a unique state in terms of the desirable physiological changes and the exciting reversal of the changes soon after the termination of the pregnancy. It is considered essential that to guarantee a good feto-maternal outcome the attainment of optimum anthropometric and haematological parameters are key. Our study assessed the anthropometric and haematological changes and also looked at the relationship that exists between these parameters among pregnant women.We carried out a cross-sectional descriptive study which considered 160 apparently healthy, singleton, third trimester pregnant women attending ANC at the State Specialist Hospital and 58 apparently healthy non-pregnant controls sourced from the Sokoto metropolis population. Each subject or control enrolled was contacted 3 times at 2 weekly intervals. And at each occasion they are assessed for changes in the anthropometric and haematological parameters. The response rate was 93.6% (3 pregnants and 11 controls were loss to follow up). The pregnant and control subgroups mean ages were 28.02 ± 6.81 years and 26.89 ± 5.84 years respectively (p = 0.265). Weekly weight gains of 0.48kg among the pregnant sub-group against 0.13kg obtained in the control group were recorded. BMI increase of about 0.19kg/m2 per week among the pregnant sub-group and only 0.05kg per week in the controls. 95% of the distribution of pregnant sub-group has haemoglobin and haematocrit of ≥8.9g/dL and ≥26% respectively. Among the pregnant sub-group, mean weekly haemoglobin and haematocrit drop of 0.24g/dL and 0.74% were respectively recorded. A steady rise in WBC was recorded but platelets counts dropped at an average of 5.04 x 103 /μL per week. A positive correlation between BMI and haemoglobin levels was observed (r > 0 and p < 0.05). No particular regularity in the relationship between BMI and WBC was noticed. We conclude that there was optimum weight gain and good haematological indices for

  7. Ethanol reforming using Ba0.5Sr0.5Cu0.2Fe0.8O3-δ/Ag composites as oxygen transport membranes

    NASA Astrophysics Data System (ADS)

    Park, C. Y.; Lee, T. H.; Dorris, S. E.; Park, J.-H.; Balachandran, U.

    2012-09-01

    Cobalt-free oxygen transport membranes (OTMs), Ba0.5Sr0.5Cu0.2Fe0.8O3-δ (BSCF) and its composites, Ba0.5Sr0.5Cu0.2Fe0.8O3-δ/Ag (BSCF/Ag), were fabricated by conventional solid state synthesis, and their oxygen transport properties were evaluated. The metal (Ag) content in the composite was 10-40 vol.%. Based on oxygen-permeation results, BSCF/40 vol.% Ag with Rh catalyst was selected for testing its ability to supply high-purity oxygen (from air) for ethanol reforming. It was found that the composite played an important role in producing hydrogen from ethanol reforming at 600 °C. The composite with catalyst shifted ethanol conversion toward production of hydrogen and away from production of other products, i.e., using a catalyst increased the selectivity for hydrogen in the reformate. The crystal structure, thermal expansion, coke formation, and the microstructural behavior of the OTMs are discussed.

  8. Reactive Oxygen Species and Cellular Oxygen Sensing

    PubMed Central

    Cash, Timothy P; Pan, Yi; Simon, M. Celeste

    2008-01-01

    Many organisms activate adaptive transcriptional programs to help them cope with decreased oxygen levels, or hypoxia, in their environment. These responses are triggered by various oxygen sensing systems in bacteria, yeast and metazoans. In metazoans, the hypoxia inducible factors (HIFs) mediate the adaptive transcriptional response to hypoxia by upregulating genes involved in maintaining bioenergetic homeostasis. The HIFs in turn are regulated by HIF-specific prolyl hydroxlase activity, which is sensitive to cellular oxygen levels and other factors such as tricarboxylic acid cycle metabolites and reactive oxygen species (ROS). Establishing a role for ROS in cellular oxygen sensing has been challenging since ROS are intrinsically unstable and difficult to measure. However, recent advances in fluorescence energy transfer resonance (FRET)-based methods for measuring ROS are alleviating some of the previous difficulties associated with dyes and luminescent chemicals. In addition, new genetic models have demonstrated that functional mitochondrial electron transport and associated ROS production during hypoxia are required for HIF stabilization in mammalian cells. Current efforts are directed at how ROS mediate prolyl hydroxylase activity and hypoxic HIF stabilization. Progress in understanding this process has been enhanced by the development of the FRET-based ROS probe, an vivo prolyl hydroxylase reporter and various genetic models harboring mutations in components of the mitochondrial electron transport chain. PMID:17893032

  9. 49 CFR 172.530 - OXYGEN placard.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false OXYGEN placard. 172.530 Section 172.530... SECURITY PLANS Placarding § 172.530 OXYGEN placard. (a) Except for size and color, the OXYGEN placard must... background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border...

  10. 49 CFR 172.530 - OXYGEN placard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false OXYGEN placard. 172.530 Section 172.530... SECURITY PLANS Placarding § 172.530 OXYGEN placard. (a) Except for size and color, the OXYGEN placard must... background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border...

  11. 49 CFR 172.530 - OXYGEN placard.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false OXYGEN placard. 172.530 Section 172.530... SECURITY PLANS Placarding § 172.530 OXYGEN placard. (a) Except for size and color, the OXYGEN placard must... background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border...

  12. 49 CFR 172.530 - OXYGEN placard.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false OXYGEN placard. 172.530 Section 172.530... SECURITY PLANS Placarding § 172.530 OXYGEN placard. (a) Except for size and color, the OXYGEN placard must... background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border...

  13. 49 CFR 172.530 - OXYGEN placard.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false OXYGEN placard. 172.530 Section 172.530... SECURITY PLANS Placarding § 172.530 OXYGEN placard. (a) Except for size and color, the OXYGEN placard must... background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border...

  14. Rockets using Liquid Oxygen

    NASA Technical Reports Server (NTRS)

    Busemann, Adolf

    1947-01-01

    It is my task to discuss rocket propulsion using liquid oxygen and my treatment must be highly condensed for the ideas and experiments pertaining to this classic type of rocket are so numerous that one could occupy a whole morning with a detailed presentation. First, with regard to oxygen itself as compared with competing oxygen carriers, it is known that the liquid state of oxygen, in spite of the low boiling point, is more advantageous than the gaseous form of oxygen in pressure tanks, therefore only liquid oxygen need be compared with the oxygen carriers. The advantages of liquid oxygen are absolute purity and unlimited availability at relatively small cost in energy. The disadvantages are those arising from the impossibility of absolute isolation from heat; consequently, allowance must always be made for a certain degree of vaporization and only vented vessels can be used for storage and transportation. This necessity alone eliminates many fields of application, for example, at the front lines. In addition, liquid oxygen has a lower specific weight than other oxygen carriers, therefore many accessories become relatively larger and heavier in the case of an oxygen rocket, for example, the supply tanks and the pumps. The advantages thus become effective only in those cases where definitely scheduled operation and a large ground organization are possible and when the flight requires a great concentration of energy relative to weight. With the aim of brevity, a diagram of an oxygen rocket will be presented and the problem of various component parts that receive particularly thorough investigation in this classic case but which are also often applicable to other rocket types will be referred to.

  15. The effects of oxygen pressure on disordering and magneto-transport properties of Ba2FeMoO6 thin films grown via pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Kim, Kyeong-Won; Ghosh, Siddhartha; Buvaev, Sanal; Mhin, Sungwook; Jones, Jacob L.; Hebard, Arthur F.; Norton, David P.

    2015-07-01

    Epitaxial Ba2FeMoO6 thin films were grown via pulsed laser deposition under low oxygen pressure and their structural, chemical, and magnetic properties were examined, focusing on the effects of oxygen pressure. The chemical disorder, off-stoichiometry in B site cations (Fe and Mo) increased with increasing oxygen pressure and thus magnetic properties were degraded. Interestingly, in contrast, negative magneto-resistance, which is the characteristics of this double perovskite material, was enhanced with increasing oxygen pressure. It is believed that phase segregation of highly disordered thin films is responsible for the increased magneto-resistance of thin films grown at high oxygen pressure. The anomalous Hall effect, which behaves hole-like, was also observed due to spin-polarized itinerant electrons under low magnetic field below 1 T and the ordinary electron-like Hall effect was dominant at higher magnetic fields.

  16. Different doses of prophylactic platelet transfusion for preventing bleeding in patients with haematological disorders after chemotherapy or stem cell transplantation

    PubMed Central

    Estcourt, Lise J; Stanworth, Simon; Doree, Carolyn; Trivella, Marialena; Hopewell, Sally; Murphy, Michael F; Tinmouth, Alan

    2014-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether different doses of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect their efficacy and safety in preventing bleeding in patients with haematological disorders after chemotherapy with or without stem cell transplantation. PMID:25722652

  17. The impact of dietary protein intake on serum biochemical and haematological profiles in vervet monkeys.

    PubMed

    Johnson, Q; Veith, W J; Mouton, T

    2001-02-01

    This study evaluated the influence of Westernised and traditional African diets on biochemical and haematological profiles in vervet monkeys (Cercopithecus aethiops). Twelve adult male vervet monkeys bred at the Medical Research Council, all over 4 years of age and weighing more than 5 kg each, were divided into two groups of six individuals. These monkeys were raised on a standard in-house diet post-weaning, before they were fed for 8 weeks on diets containing milk solids (17.2%) or maize + legume (17.4%), as sources of high crude protein (+/- 3.5 g/kg). High protein diets had no significant effect on serum biochemical indices such as aspartate aminotransferase (AST) and gamma glutamyl transferase (GGT) concentrations (P > 0.10). However, alanine aminotransferase (ALT) concentrations were significantly higher during week 8 (P < 0.05) for the maize + legume protein group. Alkaline phosphatase (ALP; P < 0.07), total protein (P < 0.0001), albumin (P < 0.02), and bilirubin (P < 0.003) were elevated in the milk solids group, while glucose levels were also significantly higher for the milk solids group (P < 0.05) between weeks 2 and 6. Elevated protein intake had no significant effect on haematological parameters such as red blood cells (RBC), platelet and white blood cell (WBC) counts, haemoglobin levels and monocyte and neutrophil concentrations (P > 0.10). In contrast, serum lymphocyte levels were significantly raised in the maize + legume protein group (P = 0.03), whereas values for the haematocrit (P < 0.002), mean cell volume (MCV; P < 0.03) and mean corpuscular haemoglobin concentration (MCHC; P < 0.0001) were higher in the monkeys that were fed the milk solids. This investigation showed that the type of dietary protein that is consumed may well affect certain biochemical and haematological indices in vervet monkeys. Compared to the group that were given the traditional African food regime, the animals on the Western-type milk solids diet showed significant

  18. Effect of Probiotic Dietary Intervention on Calcium and Haematological Parameters in Geriatrics

    PubMed Central

    Prajapati, Jashbhai B.; Mudgal, Sreeja V.; Pandya, Himanshu V.; Singh, Uday Shankar; Trivedi, Sunil S.; Phatak, Ajay G.; Patel, Rupal M.

    2016-01-01

    Introduction Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Sufficient calcium intake has been reported to support bone growth and prevent bone loss during the ageing process. Aim To determine the effect of Lactobacillus helveticus MTCC 5463 probiotic dietary intervention on serum calcium & haematological parameters in geriatric population. Materials and Methods Healthy volunteers with age ranging from 64-74 years were recruited from the nearby residential areas in and around Anand, Gujarat. Study duration was from 2012 to 2015. Of the 112 subjects initially enrolled in the trial, 36 withdrew before the intervention because of not matching with criterias. Of the 76 participants, 5 subjects (4%) under test group and 12 subjects (11%) under placebo left the study. We had 59 subjects who successfully completed a double blind cross over trial. Probiotic fermented milk products (in form of “Lassi”) was prepared by supplementing toned milk with honey and fermenting with probiotic Lactobacillus helveticus MTCC 5463 and Streptococcus thermophilus MTCC 5460. The final product had at least 108 CFU/ml of viable Lactobacillus helveticus MTCC 5463 at the time of feeding. During feeding period, 200 ml of fermented product containing the test strain to one group and a similar product but without the test strain as placebo were fed regularly at the time of breakfast in morning for 4 weeks. Subjects of each group were given a washout period of 4 weeks before they were crossed over and included to the other group. The study was approved by institutional ethics committee. Results The socio-demographic and clinical profiles were similar at baseline. The mean (SD) calcium level improved significantly in test {9.36 (0.45) vs 8.45 (0.61), p<0.001}. No significant effect was observed with respect to haemoglobin & haematological parameters. Conclusion The well-documented probiotic Lactobacillus helveticus MTCC 5463

  19. Audit of clinical-laboratory practices in haematology and blood transfusion at Muhimbili National Hospital in Tanzania.

    PubMed

    Makubi, Abel N; Meda, Collins; Magesa, Alex; Minja, Peter; Mlalasi, Juliana; Salum, Zubeda; Kweka, Rumisha E; Rwehabura, James; Quaresh, Amrana; Magesa, Pius M; Robert, David; Makani, Julie; Kaaya, Ephata

    2012-10-01

    In Tanzania, there is paucity of data for monitoring laboratory medicine including haematology. This therefore calls for audits of practices in haematology and blood transfusion in order to provide appraise practice and devise strategies that would result in improved quality of health care services. This descriptive cross-sectional study which audited laboratory practice in haematology and blood transfusion at Muhimbili National Hospital (MNH) aimed at assessing the pre-analytical stage of laboratory investigations including laboratory request forms and handling specimen processing in the haematology laboratory and assessing the chain from donor selection, blood component processing to administration of blood during transfusion. A national standard checklist was used to audit the laboratory request forms (LRF), phlebotomists' practices on handling and assessing the from donor selection to administration 6f blood during transfusion. Both interview and observations were used. A total of 195 LRF were audited and 100% of had incomplete information such as patients' identification numbers, time sample ordered, reason for request, summary of clinical assessment and differential diagnoses. The labelling of specimens was poorly done by phlebotomists/clinicians in 82% of the specimens. Also 65% (132/202) of the blood samples delivered in the haematology laboratory did not contain the recommended volume of blood. There was no laboratory request form specific for ordering blood and there were no guidelines for indication of blood transfusion in the wards/ clinics. The blood transfusion laboratory section was not participating in external quality assessment and the hospital transfusion committee was not in operation. It is recommended that a referral hospital like MNH should have a transfusion committee to provide an active forum to facilitate communication between those involved with transfusion, monitor, coordinate and audit blood transfusion practices as per national

  20. Infrared and transport properties of the layered perovskite related oxide Ba 5Nb 4O 15 and its oxygen deficient phases

    NASA Astrophysics Data System (ADS)

    Pagola, S.; Massa, N. E.; Polla, G.; Leyva, G.; Carbonio, R. E.

    1994-12-01

    Ba 5Nb 4O 15-x oxides were studied by infrared, electrical resistivity and thermogravimmetric analysis (TGA). FIR reflectivity measurementsreveal a strong ionic compound that has well defined features in groups that we assign to oxygen stretching, bending and lattice phonons splitted by the lower symmetry of this layered compound. For the sample with x = 0.56, oxygen vacancies do not affect phonon band profiles, indicating that carriers are not free enough to interact with longitudinal modes. Electrical resistivity vs. temperature measurements show that the oxygen deficient compounds, for low values of x, are small band gap semiconductors.

  1. Oxygen Therapy

    MedlinePlus

    ... 85-95% pure oxygen. The concentrator runs on electricity or a battery. A concentrator for home usually ... systems deliver 100% oxygen, and do not require electricity. A small canister can be filled from the ...

  2. Oxygen analyzer

    DOEpatents

    Benner, William H.

    1986-01-01

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  3. Studies on the alterations in haematological indices, micronuclei induction and pathological marker enzyme activities in Channa punctatus (spotted snakehead) perciformes, channidae exposed to thermal power plant effluent.

    PubMed

    Javed, Mehjbeen; Ahmad, Irshad; Ahmad, Ajaz; Usmani, Nazura; Ahmad, Masood

    2016-01-01

    The present study was conducted to assess the toxicity of thermal power plant effluent containing heavy metals (Fe > Cu > Zn > Mn > Ni > Co > Cr) on haematological indices, micronuclei, lobed nuclei and activity of pathological marker enzymes [alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT) and creatine kinase (CK)] in Channa punctatus. Total erythrocyte count (-54.52 %), hemoglobin (-36.98 %), packed cell volume (-36.25 %), mean corpuscular hemoglobin concentration (-1.41 %) and oxygen (O2) carrying capacity (-37.04 %) declined significantly over reference fish, however total leukocyte count (+25.43 %), mean corpuscular hemoglobin (+33.52 %) and mean corpuscular volume (+35.49 %) showed elevation. High frequency of micronuclei (1133.3 %) and lobed nuclei (150 %) were observed in exposed fish which may indicate mutagenesis. Activities of pathological marker enzymes ALP, AST, ALT and CK increased significantly in serum of exposed fish. The ratio of ALT: AST in exposed fish was beyond 1 which indicates manifestation of pathological processes. These biomarkers show that fish have macrocytic hypochromic anemia. Leukocytosis showed general defence response against heavy metal toxicity and marker enzymes showed tissue degeneration. In conclusion, thermal power plant effluent has strong potential to induce micronuclei, tissue pathology, making the fish anemic, weak, stressed and vulnerable to diseases. PMID:27386247

  4. Haematological profile in leprosy. Part II--Relationship to severity of disease and treament status.

    PubMed

    Karat, A B; Rao, P S

    1978-01-01

    321 adult male lepromatous leprosy patients were studied for relationship between haematological findings, severity of disease and duration of treatment. Significant changes were noticed in relation in haemoglobin concentration, serum vitamin B12 and serum folate levels, serum albumin and globulin. No significant changes were observed in serum iron levels in relation to disease and treatment status. With rising bacterial load, there was a trend towards lower haemoglobin concentration, higher vitamin B12 level and lowered serum folate levels. Serum albumin showed a significant decline, while serum globulin showed a significant rise. The findings are discussed in relation to replacement of bone marrow by lepromatous tissue as well as possible interference in the metabolism of haematinics by M. leprae. The exact mechanism of neurlogical deficit in leprosy in relation to deficiency of vitamin B12 and folic acid need to be further elucidated. PMID:651316

  5. Cellular therapy to treat haematological and other malignancies: progress and pitfalls.

    PubMed

    Fromm, Phillip D; Gottlieb, David; Bradstock, Kenneth F; Hart, Derek N J

    2011-10-01

    The recent Food and Drug Administration (FDA) approval of a cellular therapy to treat castration resistant prostate cancer has reinforced the potential of cellular therapy to consolidate current pharmacological approaches to treating cancer. The emergence of the cell manufacturing facility to facilitate clinical translation of these new methodologies allows greater access to these novel therapies. Here we review different strategies currently being explored to treat haematological malignancies with a focus on adoptive allogeneic or autologous transfer of antigen specific T cells, NK cells or dendritic cells. These approaches all aim to generate immunological responses against overexpressed tissue antigens, mismatched minor histocompatability antigens or tumour associated antigens. Current successes and limitations of these different approaches will be discussed with an emphasis on challenges encountered in generating long term engraftment, antigen selection and implementation as well as therapeutic immune monitoring of clinical responses, with examples from recent clinical trials. PMID:21897329

  6. Tales from the Jazz ASH: highlights from the 2013 American Society of Haematology meeting.

    PubMed

    Mazzarella, Luca

    2014-01-01

    The 55th annual ASH meeting was held in pleasant New Orleans and was the largest in its history, with 22,495 participants coming from 113 nations. A 'bench-to-bedside and back' attitude characterises haematology probably more than any other discipline in medicine and, as usual, this was reflected in the extremely wide breadth of the topics covered, including the last results from clinical trials and cutting-edge advancements in basic science. This year, the balance was arguably skewed: few truly clinical practice-changing results were presented. On the other hand, a great number of basic and translational studies significantly increased our understanding of the biology of numerous malignancies and heralded the coming of age of disruptive technologies. Namely, above all, next generation sequencing and T cell engineering-based cell therapy. PMID:24678345

  7. First report of blood parasites in fishes from Kashmir and their effect on the haematological profile

    PubMed Central

    Shahi, N.; Yousuf, A.R.; Rather, M.I.; Ahmad, F.; Yaseen, T.

    2013-01-01

    Cyprinus carpio communis Linnaeus, Carassius carassius Linnaeus, Schizothorax curvifrons Heckel and Triplophysa marmorata species of fishes were captured from Anchar Lake and river Jhelum of Kashmir Himalaya for hematological and parasitological analysis. During the investigation haemoflagellates from the genus Babesiosoma and Trypanosoma were recorded in the blood smears. Trypanosomes were present in all the species except C. carpio, whereas Babesiosoma were only found in T. marmorata. Haematological analysis revealed a significant (p<0.01) reduction in red blood cell count in the fishes infected with Babesiosoma and Trypanosoma. A significant decrease (p<0.05) was recorded in haemoglobin value and packed cell volume in the infected fishes in comparison to the non-infected fishes. PMID:26623319

  8. Intensify, resuscitate or palliate: decision making in the critically ill patient with haematological malignancy.

    PubMed

    Hill, Quentin A

    2010-01-01

    The survival prospects of critically ill patients with haematological malignancy (HM) are reviewed, as are the variables which might influence decisions about the limitation of life sustaining therapies (LLST). Approximately 40% of patients with HM admitted to ICU survive to hospital discharge and a broad admission policy is warranted. Short term survival is predicted by the severity of the underlying physiological disturbance rather than cancer specific characteristics, although the prognostic importance of neutropenia and prior stem cell transplantation remains to be clarified. Survival to hospital discharge in cancer patients following cardio-pulmonary resuscitation (CPR) is only 6-8%. Poor performance status and progressive deterioration despite ICU support appear to predict worse outcome. Patients should be provided with realistic information in order to make an informed decision about CPR. Decisions about LLST must be individualised. Consideration should be given to the patient's wishes and prognosis, the immediate clinical circumstances and their potential reversibility. PMID:19913962

  9. Effect of acute exercise on some haematological parameters and neutrophil functions in active and inactive subjects.

    PubMed

    Benoni, G; Bellavite, P; Adami, A; Chirumbolo, S; Lippi, G; Brocco, G; Cuzzolin, L

    1995-01-01

    In this work we studied the possible effects of acute exercise on some haematological parameters and on some functions of neutrophils in seven active and six inactive subjects. Physical exercise (10 min on a cycle ergometer at a heart rate of 150 beats.min-1) induced a significant increase in total leucocyte, lymphocyte and neutrophil concentrations in active subjects; serum iron and ferritin concentrations were lower in active compared to inactive subjects. Cellular adhesion, bactericidal activity and superoxide anion production did not change after exercise, while we also observed some differences between active and inactive subjects before exercise. In particular, the neutrophils from active subjects showed a significantly higher percentage of adhesion, higher bactericidal activity and lower superoxide anion production. In conclusion, the training induced changes in some neutrophil functions, while acute exercise influenced, overall, leucocyte concentrations. PMID:7768243

  10. Role of Haematological Changes in Predicting Occurrence of Leishmaniasis- A Study in Kumaon Region of Uttarakhand

    PubMed Central

    Pant, Prabhat; Chachra, Upasna; Singh, Paramjeet; Thapliyal, Naveen; Rawat, Vinita

    2016-01-01

    Introduction A number of cases of Leishmaniasis have been reported from non-endemic sub-himalayan regions of India. Due to low clinical suspicion and atypical presentation, cases may go undetected or there may be a delay in diagnosis. Aim The aim of the study was to evaluate clinico-haematological parameters and bone marrow findings so that a high degree of suspicion could be made in unsuspected cases of Visceral Leishmaniasis (VL) and Leishman Donovan (LD) body negative bone marrow smears. Materials and Methods A retrospective study was conducted at a tertiary care centre serving the kumaon region of Uttarakhand from 2010 to 2014. Forty bone marrow aspirates were included, which were sent on clinical suspicion of VL. Twenty cases were positive for LD bodies. Their clinico-haematological features including bone marrow findings were studied in detail and compared with rest of the 20 LD negative cases. Five LD negative cases were also positive for rk39. Results Twenty LD positive cases were evaluated. Splenomegaly was the most common sign present in 17 cases (85%). Anaemia, leucopenia and lymphocytosis were present in all the cases (100%). Pancytopenia was seen in 17 cases (85%). Microcytic hypochromic blood picture was the most common finding in 11 cases (55%). Bone marrow was normocellular in 7 cases (35%), hypercellular in 7 cases (35%). Erythropoesis was micro-normoblastic in 11 cases (55%). Overall, there were 25 cases of VL (20 LD positive, 5 LD negative). Increased plasma cells, lymphocytes and histiocytes were seen in 17 cases (68%) of VL. Conclusion In non-endemic region where clinical suspicion is low, bone marrow findings can be a strong indicator for VL even though marrow is negative for LD bodies. If required other ancillary investigations can also be ordered. This study also emphasizes the need for epidemiological work up in this region.

  11. Effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus).

    PubMed

    Jia, Rui; Han, Cen; Lei, Ji-Lin; Liu, Bao-Liang; Huang, Bin; Huo, Huan-Huan; Yin, Shu-Ting

    2015-12-01

    Nitrite (NO2(-)) is commonly present as contaminant in aquatic environment and toxic to aquatic organisms. In the present study, we investigated the effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus). Fish were exposed to various concentrations of nitrite (0, 0.02, 0.08, 0.4 and 0.8mM) for 96 h. Fish blood and gills were collected to assay haematological parameters, oxidative stress and expression of genes after 0, 24, 48 and 96 h of exposure. In blood, the data showed that the levels of methemoglobin (MetHb), triglyceride (TG), potassium (K(+)), cortisol, heat shock protein 70 (HSP70) and glucose significantly increased in treatments with higher concentrations of nitrite (0.4 and/or 0.8mM) after 48 and 96 h, while the levels of haemoglobin (Hb) and sodium (Na(+)) significantly decreased in these treatments. In gills, nitrite (0.4 and/or 0.8mM) apparently reduced the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH), increased the formation of malondialdehyde (MDA), up-regulated the mRNA levels of c-jun amino-terminal kinase (JUK1), p53, caspase-3, caspase-7 and caspase-9 after 48 and 96 h of exposure. The results suggested caspase-dependent and JUK signaling pathways played important roles in nitrite-induced apoptosis in fish. Further, this study provides new insights into how nitrite affects the physiological responses and apoptosis in a marine fish. PMID:26476021

  12. Haematological effects of multimicronutrient supplementation in non-pregnant Gambian women

    PubMed Central

    Gulati, Ruchi; Bailey, Robin; Prentice, Andrew M.; Brabin, Bernard J.; Owens, Stephen

    2009-01-01

    Background/Objectives: The use of multimicronutrient (MMN) supplementation to reduce the burden of anaemia in non-pregnant women of reproductive age has been little studied, particularly in Africa. The objective of the study was to evaluate haematological outcomes in non-pregnant, rural Gambian women of reproductive age, receiving daily MMN supplements for one-year. Subjects/Methods: The study in 293 women aged from 17 to 45 years old was nested within a double-blind, randomised placebo-controlled trial of periconceptional MMN supplementation [ISRCTN 13687662], using the United Nations International Multiple Micronutrient Preparation (UNIMMAP), received daily for one year or until conception. Red cell parameters and free erythrocyte protoporphyrin concentration were measured at baseline and after 12-months in those women who did not conceive. Results: Anaemic women (haemoglobin concentration <12g/dL) were more likely to be older and in economic deficit at baseline. Mean change in haemoglobin concentration was +0.6±1.4g/dL in the intervention arm and −0.2±1.2g/dL in the placebo arm (p<0.001). After supplementation with MMN the relative risk of anaemia (<12g/dL) was 0.59 (0.46, 0.76) compared to placebo. Anaemic subjects at baseline showed an increase in mean haemoglobin from 10.6g/dL to 11.8g/L (p<0.001) after MMN supplementation. Conclusion: MMN supplementation should be considered as a strategy for improving the micronutrient and haematological status of non-pregnant women of reproductive age. PMID:19259112

  13. Blood gases, biochemistry and haematology of Galápagos marine iguanas (Amblyrhynchus cristatus).

    PubMed

    Lewbart, Gregory A; Hirschfeld, Maximilian; Brothers, J Roger; Muñoz-Pérez, Juan Pablo; Denkinger, Judith; Vinueza, Luis; García, Juan; Lohmann, Kenneth J

    2015-01-01

    The marine iguana, Amblyrhynchus cristatus, is an iconic lizard endemic to the Galápagos Islands of Ecuador, but surprisingly little information exists on baseline health parameters for this species. We analysed blood samples drawn from 35 marine iguanas captured at three locations on San Cristóbal Island. A portable blood analyser (iSTAT) was used to obtain near-immediate field results for pH, lactate, partial pressure of O2, partial pressure of CO2, bicarbonate (HCO3 (-)), percentage O2 saturation, haematocrit, haemoglobin, sodium, potassium, ionized calcium and glucose. Parameter values affected by temperature were auto-corrected by the iSTAT. Standard laboratory haematology techniques were employed for differential white blood cell counts and haematocrit determination; resulting values were also compared with the haematocrit values generated by the iSTAT. Body temperature, heart rate, respiratory rate and body measurements were also recorded. Body length was positively correlated with several blood chemistry values (HCO3 (-) and glucose) and two haematology parameters (haemoglobin and manually determined haematocrit). A notable finding was the unusually high blood sodium level; the mean value of 178 mg/dl is among the highest known for any reptile. This value is likely to be a conservative estimate because some samples exceeded the maximal value the iSTAT can detect. For haematocrit determination, the iSTAT blood analyser yielded results significantly lower than those obtained with high-speed centrifugation. The values reported in this study provide baseline data that may be useful in comparisons among populations and in detecting changes in health status among marine iguanas affected by natural disturbances or anthropogenic threats. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease. PMID:27293719

  14. Correlation between the electronic and atomic structure, transport properties, and oxygen vacancies on La{sub 0.7}Ca{sub 0.3}MnO{sub 3} thin films

    SciTech Connect

    Rubio-Zuazo, J. Onandia, L.; Castro, G. R.

    2014-01-13

    We present a study of the role of oxygen vacancies on the atomic and electronic structure and transport properties on a 20 nm thick La{sub 0.7}Ca{sub 0.3}MnO{sub 3} film grown by the pulsed laser deposition method on a SrTiO{sub 3} (001) substrate. The results show that oxygen vacancies induce an atomic structure modification characterized by the movement of the La/Ca cations to the perovskite regular position, by the reduction of the MnO{sub 6} basal plane rotation, and by a cooperative tilting of the octahedra along the out-of-plane direction. The out-of-plane lattice parameter increases due to the reduction of the Mn valence upon oxygen vacancies creation. As a consequence, a shift of the Metal-to-Insulator transition to lower temperatures is found to occur. We discuss the influence of the competitive phenomena of manganese valence and Mn-O-Mn bond distortion on the transport properties of manganite thin films.

  15. Oxygen analyzer

    DOEpatents

    Benner, W.H.

    1984-05-08

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N/sub 2/), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable obtained by decomposing the sample at 1135/sup 0/C, or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135/sup 0/C as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N/sub 2/, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  16. 49 CFR 173.168 - Chemical oxygen generators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Chemical oxygen generators. 173.168 Section 173... Class 7 § 173.168 Chemical oxygen generators. An oxygen generator, chemical (defined in § 171.8 of this subchapter) may be transported only under the following conditions: (a) Approval. A chemical oxygen...

  17. 49 CFR 173.168 - Chemical oxygen generators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Chemical oxygen generators. 173.168 Section 173... Class 7 § 173.168 Chemical oxygen generators. An oxygen generator, chemical (defined in § 171.8 of this subchapter) may be transported only under the following conditions: (a) Approval. A chemical oxygen...

  18. 49 CFR 173.168 - Chemical oxygen generators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Chemical oxygen generators. 173.168 Section 173... Class 7 § 173.168 Chemical oxygen generators. An oxygen generator, chemical (defined in § 171.8 of this subchapter) may be transported only under the following conditions: (a) Approval. A chemical oxygen...

  19. 49 CFR 173.168 - Chemical oxygen generators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Chemical oxygen generators. 173.168 Section 173... Class 7 § 173.168 Chemical oxygen generators. An oxygen generator, chemical (defined in § 171.8 of this subchapter) may be transported only under the following conditions: (a) Approval. A chemical oxygen...

  20. 49 CFR 173.168 - Chemical oxygen generators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Chemical oxygen generators. 173.168 Section 173... Class 7 § 173.168 Chemical oxygen generators. An oxygen generator, chemical (defined in § 171.8 of this subchapter) may be transported only under the following conditions: (a) Approval. A chemical oxygen...

  1. The effect of Ta ``oxygen scavenger layer'' on HfO2-based resistive switching behavior: termodynamic stability, electronic structure, and low-bias transport

    NASA Astrophysics Data System (ADS)

    Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; Nakamura, Hisao; Asai, Yoshihiro; Heinonen, Olle

    Metal-oxide-metal heterostructures are promising candidates for next-generation random access memories, which exhibit reversible resistive switching between high- and low-conductance states. Recent experimental work showed that inserting a metallic `oxygen scavenger layer' between TiN electrode and HfO2 significantly improves device switching performance. We show, using atomistic modeling within the GGA +U scheme of Density Functional Theory, that a Ta oxygen scavenger layer significantly enhances the thermodynamic stability of depleting oxygen from the oxide. Furthermore, the presence of a Ta layer reduces the dependence of the Schottky barrier heights on the location of the oxygen removed from the oxide matrix. Finally, the Schottky barrier height has a very small effect on the on-state low-bias conductance; this is more sensitive to the location of the depleted oxygen. We gratefully acknowledge the computing resources provided on Blues, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Work at Argonne was supported by U. S. DOE, Office of Science under Contract No. DE-AC02-06CH11357.

  2. Safety of anticoagulation in the treatment of venous thromboembolism in patients with haematological malignancies and thrombocytopenia: Report of 5 cases and literature review.

    PubMed

    Lim, Ming Sheng; Enjeti, Anoop K

    2016-09-01

    Venous thromboembolism (VTE) is relatively common among patients with haematological malignancies. Management is challenging because many of these patients are also thrombocytopenic and at increased risk of bleeding. Current recommendations regarding the treatment of VTE in thrombocytopenic patients with haematological malignancies are limited as there only few studies evaluating the safety and efficacy of anticoagulation in this population of patient. A literature review on the safety of antithrombotic therapy for treatment or prophylaxis of VTE in patients with haematological malignancies was undertaken. This includes a report on 5 patients with haematological malignancies at our institute who received enoxaparin for treatment of VTE while thrombocytopenic. Unlike previous case series which showed that the use of LMWH (low molecular weight heparin) is safe in this group of patients, major bleeding occurred in 2 patients, and was fatal in one case. More studies are required to evaluate the risk factors and safety of anticoagulation in these patients. PMID:27397486

  3. Oxygen and hydrogen isotopes of rainfall and dripwater at DeSoto Caverns (Alabama, USA): Key to understanding past variability of moisture transport from the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Lambert, W. Joe; Aharon, Paul

    The Southeast and the US Gulf Coast in particular are notably lacking isotope data in the water cycle despite the fact that moisture transport from the Gulf of Mexico (GOM) has a considerable influence on both regional and continental rainfall patterns. This study reports time-series of oxygen and hydrogen isotopes acquired over a 3-year period (2005-2008) from GOM-derived rainfall, cave dripwater and shallow groundwaters, and offers valuable insights on the links between factors controlling regional rainfall and the ubiquitous karst hydrology. Amount-weighted mean monthly rainwater δ18O and δD values in Tuscaloosa, Alabama range from -1.5 to -8.3‰ and -1.2 to -49.5‰, respectively, and show mean seasonal amplitudes of ˜4‰ ( δ18O) and ˜25‰ ( δD). In comparison d-excess values display large seasonal amplitudes of 10-20‰ resulting from differences in the degree of evaporation from falling raindrops between summer and winter months, and correlate well with the coeval air temperature ( r2 = 0.59; p < 0.05). Deviations of the Gulf Coast Meteoric Water Line (GCMWL) slope and d-excess from the global meteoric water line (GMWL) are attributed to different rates of evaporation after condensation, and to humidity contrast between the cloud boundary layer and the surrounding atmosphere in the vapor source region, respectively. Rainfall amounts declined during the study interval from an excessive "wet" year, ascribed to six tropical storms incursions during an unusually active hurricane season in 2005, to an onset of a regional drought during 2007-2008 with monthly rainfall amounts substantially below normal values (30-year monthly means). An interannual trend of 18O and 2H enrichments is discerned from 2005 to 2008 (1.4‰ and 11.6‰, respectively) coeval with the decline in rainfall amounts. Dripwater samples from nearby DeSoto Caverns show weak δ18O and δD seasonal variations and record only 20% and 51% of the 18O and 2H enrichments, respectively

  4. Guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen. Working Party of the British Committee for Standards in Haematology Clinical Haematology Task Force.

    PubMed Central

    1996-01-01

    Overwhelming postsplenectomy infection should be preventable if simple precautions are taken. An ad hoc working party of the British Committee for Standards in Haematology has reviewed recommendations for patients without a spleen and drawn up a consensus. Members of the working party were selected for their personal expertise and to represent relevant professional bodies. The guidelines, which are set out below, include and extend the chief medical officer's 1994 update. PMID:8601117

  5. EMQN Best Practice Guidelines for molecular and haematology methods for carrier identification and prenatal diagnosis of the haemoglobinopathies

    PubMed Central

    Traeger-Synodinos, Joanne; Harteveld, Cornelis L; Old, John M; Petrou, Mary; Galanello, Renzo; Giordano, Piero; Angastioniotis, Michael; De la Salle, Barbara; Henderson, Shirley; May, Alison

    2015-01-01

    Haemoglobinopathies constitute the commonest recessive monogenic disorders worldwide, and the treatment of affected individuals presents a substantial global disease burden. Carrier identification and prenatal diagnosis represent valuable procedures that identify couples at risk for having affected children, so that they can be offered options to have healthy offspring. Molecular diagnosis facilitates prenatal diagnosis and definitive diagnosis of carriers and patients (especially ‘atypical' cases who often have complex genotype interactions). However, the haemoglobin disorders are unique among all genetic diseases in that identification of carriers is preferable by haematological (biochemical) tests rather than DNA analysis. These Best Practice guidelines offer an overview of recommended strategies and methods for carrier identification and prenatal diagnosis of haemoglobinopathies, and emphasize the importance of appropriately applying and interpreting haematological tests in supporting the optimum application and evaluation of globin gene DNA analysis. PMID:25052315

  6. The Effect of Cement Dust Exposure on Haematological Parameters of Cement Factory workers in Nalagonda, Andhra Pradesh.

    NASA Astrophysics Data System (ADS)

    Guguloth, Mohan Rao.; Sambanaik, A.; srinivasnaik, L.; Mude, Jagadishnaik.

    2012-10-01

    This study was measured on haematological parameters in workers exposed to cement dust in order to test the the hypothesis and to identify a simple, readily available, cost effective screening test that could help in identifying the presence of disease, its severity, that Cement dust exposure may perturb these functions related to their workplace.Assesment of haematological parameters were performed in 100exposed workers occupationally exposed to cement dust and 50 matched unexposed controls with ages ranging from 20-35, 35-50, 50-65 years. The blood samples were taken from them and percentage of hemoglobin, Lymphocytes / monocytes count were analysed.The hemoglobin percentage of exposed workers were significantly lower(P<0.05).Lymphocytes/Monocytes counts of exposed workers was insignificant (P<0.05).These results suggest that long term occupational exposure to cement dust may perturb haemopoietic function.

  7. Can exome scans be expected to be part of real-time decision-making in patients with haematological cancers?

    PubMed

    Hokland, Peter; Cotter, Finbarr E; Hansen, Marcus C

    2016-08-01

    The laboratory aspects of diagnosis of patients with haematological malignancies are forever changing. Microscopic examination of blood and bone marrow smears, cytogenetics, flow cytometry and single-assay molecular diagnostics have been and are still essential tools in cancer diagnostics. Flow cytometry has brought the unprecedented possibility of rapid multiplexing and characterization of complex immunophenotypic patterns. However, the advent of next generation sequencing in the haematology laboratory brings a whole new perspective on multiplexing and potentially lowers the cost per analysis effectively. These informative methods still require skilled technicians and bioinformaticians, evolve at a rapid pace, and call for clinical guidelines and best practice. Here, we discuss the potential and caveats of whole exome sequencing as it moves closer to routine laboratory practice. The question is: Will exome sequencing be performed, real-time, in the standard haemodiagnostic laboratory? PMID:27351467

  8. EMQN Best Practice Guidelines for molecular and haematology methods for carrier identification and prenatal diagnosis of the haemoglobinopathies.

    PubMed

    Traeger-Synodinos, Joanne; Harteveld, Cornelis L; Old, John M; Petrou, Mary; Galanello, Renzo; Giordano, Piero; Angastioniotis, Michael; De la Salle, Barbara; Henderson, Shirley; May, Alison

    2015-04-01

    Haemoglobinopathies constitute the commonest recessive monogenic disorders worldwide, and the treatment of affected individuals presents a substantial global disease burden. Carrier identification and prenatal diagnosis represent valuable procedures that identify couples at risk for having affected children, so that they can be offered options to have healthy offspring. Molecular diagnosis facilitates prenatal diagnosis and definitive diagnosis of carriers and patients (especially 'atypical' cases who often have complex genotype interactions). However, the haemoglobin disorders are unique among all genetic diseases in that identification of carriers is preferable by haematological (biochemical) tests rather than DNA analysis. These Best Practice guidelines offer an overview of recommended strategies and methods for carrier identification and prenatal diagnosis of haemoglobinopathies, and emphasize the importance of appropriately applying and interpreting haematological tests in supporting the optimum application and evaluation of globin gene DNA analysis. PMID:25052315

  9. Functional and Biological Role of Endothelial Precursor Cells in Tumour Progression: A New Potential Therapeutic Target in Haematological Malignancies.

    PubMed

    Reale, Antonia; Melaccio, Assunta; Lamanuzzi, Aurelia; Saltarella, Ilaria; Dammacco, Franco; Vacca, Angelo; Ria, Roberto

    2016-01-01

    It was believed that vasculogenesis occurred only during embryo life and that postnatal formation of vessels arose from angiogenesis. Recent findings demonstrate the existence of Endothelial Precursor Cells (EPCs), which take partin postnatal vasculogenesis. EPCs are recruited from the bone marrow under the stimulation of growth factors and cytokines and reach the sites of neovascularization in both physiological and pathological conditions such as malignancies where they contribute to the "angiogenic switch" and tumor progression. An implementation of circulating EPCs in the bloodstream of patients with haematological malignancies has been demonstrated. This increase is strictly related to the bone marrow microvessel density and correlated with a poor prognosis. The EPCs characterization is a very complex process and still under investigation. This literature review aims to provide an overview of the functional and biological role of EPCs in haematological malignancies and to investigate their potential as a new cancer therapeutic target. PMID:26788072

  10. Structure and Electronic Transport of Oxygen-Deficient SrTiO3 Thin Films Buffered with DyScO3

    NASA Astrophysics Data System (ADS)

    Balakrishnan, Purnima; Alaan, Urusa; Gray, Matthew; Suzuki, Yuri

    Oxygen deficiency in SrTiO3 (STO) induces metallic behavior in bulk and thin film form. Thus far, reports of STO thin film metallicity have been limited to homoepitaxial growth on bulk STO substrates. Growth on other substrates has suppressed metallicity, suggesting the important role of lattice distortions. In this presentation, we report on the metallicity and corresponding structure of oxygen-deficient STO films deposited on DyScO3 (DSO) buffered STO substrates and compare to STO films deposited directly on STO substrates. These films are epitaxial, atomically flat, expanded out-of-plane by ~0.6 %, and coherently strained to the STO substrate. Oxygen-deficient STO thin films grown on STO and DSO-buffered STO substrates are metallic, while films deposited on LaAlO3, (LaAlO3)(SrTaO3), and DSO substrates are insulating. The resistivities of metallic films follow a T3 dependence near room temperature, transitioning to a T2 dependence below ~100 K, and are increased by the addition of a DSO buffer. Comparison of sheet resistance across films of various thicknesses indicates the presence of an insulating layer around 7 unit cells thick. These properties indicate the importance of both oxygen deficiency and lattice structure in obtaining metallicity.

  11. Health assessment of free-ranging endangered Australian sea lion (Neophoca cinerea) pups: effect of haematophagous parasites on haematological parameters.

    PubMed

    Marcus, Alan D; Higgins, Damien P; Gray, Rachael

    2015-06-01

    Evaluation of the health status of free-ranging populations is important for understanding the impact of disease on individuals and on population demography and viability. In this study, haematological reference intervals were developed for free-ranging endangered Australian sea lion (Neophoca cinerea) pups within the context of endemic hookworm (Uncinaria sanguinis) infection and the effects of pathogen, host, and environment factors on the variability of haematological parameters were investigated. Uncinaria sanguinis was identified as an important agent of disease, with infection causing regenerative anaemia, hypoproteinaemia, and a predominantly lymphocytic-eosinophilic systemic inflammatory response. Conversely, the effects of sucking lice (Antarctophthirus microchir) were less apparent and infestation in pups appears unlikely to cause clinical impact. Overall, the effects of U. sanguinis, A. microchir, host factors (standard length, body condition, pup sex, moult status, and presence of lesions), and environment factors (capture-type and year of sampling) accounted for 26-65% of the total variance observed in haematological parameters. Importantly, this study demonstrated that anaemia in neonatal Australian sea lion pups is not solely a benign physiological response to host-environment changes, but largely reflects a significant pathological process. This impact of hookworm infection on pup health has potential implications for the development of foraging and diving behaviour, which would subsequently influence the independent survival of juveniles following weaning. The haematological reference intervals developed in this study can facilitate long-term health surveillance, which is critical for the early recognition of changes in disease impact and to inform conservation management. PMID:25724096

  12. Hyperthermal atomic oxygen generator

    NASA Technical Reports Server (NTRS)

    Khandelwal, Govind S.; Wu, Dongchuan

    1990-01-01

    Characterization of the transport properties of oxygen through silver was continued. Specifically, experiments measuring the transport through Ag(111), Ag(110), Ag(100) single crystals and through Ag0.05 Zr alloy were completed. In addition, experiments using glow discharge excitation of oxygen to assist in the transport were completed. It was found that the permeability through the different orientations of single crystal Ag was the same, but significant differences existed in the diffusivity. The experimental ratio of diffusivities, however, was in reasonable agreement with theoretical estimates. Since the solubilities of orientations must be the same, this suggests some problems with the assumption K = DS. The glow discharge experiments show that there is a substantial increase in transport (factor of six) when the upstream pressure is dissociated to some fraction of atoms (which have a much higher sticking coefficient). These results indicate that there is a significant surface limitation because of dissociative adsorption of the molecules. Experiments with the Ag0.05 Zr alloy and its high-grain boundary and defect density show a permeability of greater than a factor of two over ordinary polycrystalline Ag, but it is unclear as to whether this is because of enhanced transport through these defects or whether the Zr and defects on the surface increased the sticking coefficient and therefore the transport.

  13. Iron requirements based upon iron absorption tests are poorly predicted by haematological indices in patients with inactive inflammatory bowel disease.

    PubMed

    Lomer, Miranda C E; Cook, William B; Jan-Mohamed, Hamid Jan B; Hutchinson, Carol; Liu, Ding Yong; Hider, Robert C; Powell, Jonathan J

    2012-06-01

    Fe deficiency and Fe-deficiency anaemia are common in patients with inflammatory bowel disease (IBD). Traditional clinical markers of Fe status can be skewed in the presence of inflammation, meaning that a patient's Fe status can be misinterpreted. Additionally, Fe absorption is known to be down-regulated in patients with active IBD. However, whether this is the case for quiescent or mildly active disease has not been formally assessed. The present study aimed to investigate the relationship between Fe absorption, Fe requirements and standard haematological indices in IBD patients without active disease. A group of twenty-nine patients with quiescent or mildly active IBD and twenty-eight control subjects undertook an Fe absorption test that measured sequential rises in serum Fe over 4 h following ingestion of 200 mg ferrous sulphate. At baseline, serum Fe, transferrin saturation, non-transferrin-bound Fe (NTBI), ferritin and soluble transferrin receptor were all measured. Thereafter (30-240 min), only serum Fe and NTBI were measured. Fe absorption did not differ between the two groups (P = 0·9; repeated-measures ANOVA). In control subjects, baseline haematological parameters predicted Fe absorption (i.e. Fe requirements), but this was not the case for patients with IBD. Fe absorption is normal in quiescent or mildly active IBD patients but standard haematological parameters do not accurately predict Fe requirements. PMID:22152498

  14. A cluster of Geotrichum clavatum (Saprochaete clavata) infection in haematological patients: a first Italian report and review of literature.

    PubMed

    Del Principe, Maria Ilaria; Sarmati, Loredana; Cefalo, Mariagiovanna; Fontana, Carla; De Santis, Giovanna; Buccisano, Francesco; Maurillo, Luca; De Bellis, Eleonora; Postorino, Massimiliano; Sconocchia, Giuseppe; Del Poeta, Giovanni; Sanguinetti, Maurizio; Amadori, Sergio; Pagano, Livio; Venditti, Adriano

    2016-09-01

    Invasive fungal infections, usually Aspergillus and Candida, represent a major cause of morbidity and mortality in patients with malignant haematological diseases, but in the last years rare fungal infections have more frequently been reported. Here, we report the clinical history of three patients affected with haematological malignancies who developed an infection caused by Geotrichum (G.) clavatum. Two out of three patients were affected by acute myeloid leukaemia (AML), and one by mantle cell lymphoma (MCL). All patients received cytarabine-based chemotherapeutic regimens and developed G. clavatum infection within 3 weeks from therapy initiation. In all cases, G. clavatum was isolated from central venous catheter and peripheral blood cultures. In vitro susceptibility test confirmed an intrinsic resistance to echinocandins and, in all cases, visceral localisations (spleen, liver and lung) were documented by total body computed tomography (CT) scan. A prolonged antifungal therapy with high doses liposomal amphotericin-B was necessary to obtain fever resolution. Only the patient with MCL died while the other two AML recovered, and one of them after received an allogeneic stem cell transplantation. We consecutively reviewed all published cases of infection caused by G. clavatum. Our experience and literature review indicate that G. clavatum can cause invasive infection in haematological patients, mainly in those with acute leukaemia. PMID:27061932

  15. Severity of Acute Respiratory Distress Syndrome in haematology patients: long-term impact and early predictive factors.

    PubMed

    Lagier, D; Platon, L; Chow-Chine, L; Sannini, A; Bisbal, M; Brun, J-P; Blache, J-L; Faucher, M; Mokart, D

    2016-09-01

    Severe forms of acute respiratory distress syndrome in patients with haematological diseases expose clinicians to specific medical and ethical considerations. We prospectively followed 143 patients with haematological malignancies, and whose lungs were mechanically ventilated for more than 24 h, over a 5-y period. We sought to identify prognostic factors of long-term outcome, and in particular to evaluate the impact of the severity of acute respiratory distress syndrome in these patients. A secondary objective was to identify the early (first 48 h from ICU admission) predictive factors for acute respiratory distress syndrome severity. An evolutive haematological disease (HR 1.71; 95% CI 1.13-2.58), moderate to severe acute respiratory distress syndrome (HR 1.81; 95% CI 1.13-2.69) and need for renal replacement therapy (HR 2.24; 95% CI 1.52-3.31) were associated with long-term mortality. Resolution of neutropaenia during ICU stay (HR 0.63; 95% CI 0.42-0.94) and early microbiological documentation (HR 0.62; 95% CI 0.42-0.91) were associated with survival. The extent of pulmonary infiltration observed on the first chest X-ray and the diagnosis of invasive fungal infection were the most relevant early predictive factors of the severity of acute respiratory distress syndrome. PMID:27418297

  16. Effect of Aqueous Extract of Telfairia occidentalis Leaf on the Performance and Haematological Indices of Starter Broilers

    PubMed Central

    P. N., Onu

    2012-01-01

    This experiment was conducted to determine the effect of aqueous extract of Telfairia occidentalis (Fluted Pumpkin) leaf on the performance and haematological indices of starter broilers. A total of 200, 8-day-old broiler chicks were randomly allotted to five (5) treatments, each with 4 replicate groups containing 10 chicks and fed with standard starter broiler diets. Telfaria occidentalis leaves extract (FPLE) was added at 0, 40, 80, 120, and 160 mL/litre of drinking water. Growth performance and haematological indices were evaluated. Results showed that there was significant (P < 0.05) difference in weight gain, feed conversion, and protein efficiency ratios of the birds among the treatments. Birds fed 80 ml FPLE/litre of water had significantly the highest weight gain and the best feed conversion and protein efficiency ratios. There was no significant (P > 0.05) variations in the feed and water intakes of the birds. Results also show no significant (P > 0.05) difference in haematological indices of birds among the treatments. The results of this study indicate that, for enhanced weight gain and feed conversion efficiency, birds should be fed 80 mL FPLE/litre of water. PMID:23738128

  17. Appreciating Oxygen

    ERIC Educational Resources Information Center

    Weiss, Hilton M.

    2008-01-01

    Photosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that…

  18. Oxygen safety

    MedlinePlus

    ... Watch out for splattering grease. It can catch fire. Keep children with oxygen away from the stove top and oven. Cooking ... under the bed. Keep liquids that may catch fire away from your oxygen. This includes cleaning products that contain oil, grease, ...

  19. Histone deacetylase inhibitor givinostat: the small-molecule with promising activity against therapeutically challenging haematological malignancies.

    PubMed

    Ganai, Shabir Ahmad

    2016-08-01

    Histone acetyl transferases and histone deacetylases (HDACs) are counteracting epigenetic enzymes regulating the turnover of histone acetylation thereby regulating transcriptional events in a precise manner. Deregulation of histone acetylation caused by aberrant expression of HDACs plays a key role in tumour onset and progression making these enzymes as candidate targets for anticancer drugs and therapy. Small-molecules namely histone deacetylase inhibitors (HDACi) modulating the biological function of HDACs have shown multiple biological effects including differentiation, cell cycle arrest and apoptosis in tumour models. HDACi in general have been described in plethora of reviews with respect to various cancers. However, no review article is available describing thoroughly the role of inhibitor givinostat (ITF2357 or [6-(diethylaminomethyl) naphthalen-2-yl] methyl N-[4-(hydroxycarbamoyl) phenyl] carbamate) in haematological malignancies. Thus, the present review explores the intricate role of novel inhibitor givinostat in the defined malignancies including multiple myeloma, acute myelogenous leukaemia, Hodgkin's and non-Hodgkin's lymphoma apart from myeloproliferative neoplasms. The distinct molecular mechanisms triggered by this small-molecule inhibitor in these cancers to exert cytotoxic effect have also been dealt with. The article also highlights the combination strategy that can be used for enhancing the therapeutic efficiency of this inhibitor in the upcoming future. PMID:27121910

  20. Analysis of the effects of malaria chemoprophylaxis in children on haematological responses, morbidity and mortality.

    PubMed Central

    Geerligs, Paul D. Prinsen; Brabin, Bernard J.; Eggelte, Teunis A.

    2003-01-01

    This paper reviews the evidence for beneficial effects of malaria chemoprophylaxis on haematological responses, morbidity, mortality, health service utilization and rebound immunity in children. As anaemia may play an important role in childhood mortality, it is important to assess evidence from controlled trials of the potential of chemoprophylaxis to reduce childhood anaemia. An analysis of trials found good evidence that malaria chemoprophylaxis improves mean haemoglobin levels and reduces severe anaemia, clinical malaria attacks, parasite and spleen rates. Significant reductions in outpatient attendance and hospital admissions have been achieved, and substantial evidence from Gambian studies shows reductions in mortality. Chemoprophylaxis in children does not seem to produce any sustained impairment of immunity to malaria, although rebound effects may be greater in children who receive prophylaxis during infancy. Short periods of targeted prophylaxis are likely to be preferable to continuous drug administration. Evidence of the protective efficacy of malaria chemoprophylaxis in children shows that this strategy could be considered within integrated health programmes for specific time periods. Intermittent routine combination therapy early in childhood may be appropriate for those living under holoendemic conditions. Large-scale studies over a number of years are needed to address this issue and the impact of this approach on health service utilization, mortality, and the emergence of drug-resistant parasites. PMID:12764517

  1. Minimal residual disease monitoring: the new standard for treatment evaluation of haematological malignancies?

    PubMed

    Hauwel, Mathieu; Matthes, Thomas

    2014-01-01

    Minimal residual disease (MRD) refers to the small number of malignant cells that remain after therapy when the patient is in remission and shows no symptoms or overt signs of disease. Current treatment protocols for haematological malignancies allow most patients to obtain some form of MRD state, but cure seldom follows and in most cases fatal relapses occur sooner or later, leaving a bitter impression of having won a battle yet lost the war. MRD detection and quantification are used for evaluation of treatment efficiency, patient risk stratification and long-term outcome prediction. Whereas multicolour flow cytometry (MCFC) and polymerase chain reaction (PCR) based methods constitute the two most commonly used techniques for MRD detection, next generation sequencing will certainly be widely employed in the future. As MRD reflects the nature of the malignant disease itself, including its sensitivity to the drug regimens applied, it constitutes the ideal method for surveillance and patient follow-up. The morphological examination of peripheral blood or bone marrow smears, although still an indispensable part of routine laboratory testing, is clearly insufficient for patient management, and clinicians should not ask themselves whether to look for MRD or not, but how and when. PMID:24452390

  2. Atlas of genetics and cytogenetics in oncology and haematology in 2013.

    PubMed

    Huret, Jean-Loup; Ahmad, Mohammad; Arsaban, Mélanie; Bernheim, Alain; Cigna, Jérémy; Desangles, François; Guignard, Jean-Christophe; Jacquemot-Perbal, Marie-Christine; Labarussias, Maureen; Leberre, Vanessa; Malo, Anne; Morel-Pair, Catherine; Mossafa, Hossein; Potier, Jean-Claude; Texier, Guillaume; Viguié, Franck; Yau Chun Wan-Senon, Sylvie; Zasadzinski, Alain; Dessen, Philippe

    2013-01-01

    The Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://AtlasGeneticsOncology.org) is a peer-reviewed internet journal/encyclopaedia/database focused on genes implicated in cancer, cytogenetics and clinical entities in cancer and cancer-prone hereditary diseases. The main goal of the Atlas is to provide review articles that describe complementary topics, namely, genes, genetic abnormalities, histopathology, clinical diagnoses and a large iconography. This description, which was historically based on karyotypic abnormalities and in situ hybridization (fluorescence in situ hybridization) techniques, now benefits from comparative genomic hybridization and massive sequencing, uncovering a tremendous amount of genetic rearrangements. As the Atlas combines different types of information (genes, genetic abnormalities, histopathology, clinical diagnoses and external links), its content is currently unique. The Atlas is a cognitive tool for fundamental and clinical research and has developed into an encyclopaedic work. In clinical practice, it contributes to the cytogenetic diagnosis and may guide treatment decision making, particularly regarding rare diseases (because they are numerous and are frequently encountered). Readers as well as the authors of the Atlas are researchers and/or clinicians. PMID:23161685

  3. Haematological, biochemical and histopathological alterations induced by abamectin and Bacillus thuringiensis in male albino rats.

    PubMed

    Eissa, F I; Zidan, N A

    2010-03-01

    The renal- and hepato-toxicity induced by abamectin pesticide (Vertimec) and a commercial form of a bio-insecticide Bacillus thuringiensis (Agerin) in male albino rats were evaluated. Blood picture and blood glucose level were investigated. Male albino rats were administered dietary doses each equivalent to 1/10 or 1/100 of the LD50 values of each toxicant for 30 consecutive days. Abamectin was found to pose risks of renal- and hepato-toxicity in rats, since the biochemical parameters of liver function (i.e. aspartate aminotransferase activity, alanine aminotransferase activity, acid phosphatase activity, albumin, and total protein levels) and kidney function (uric acid and creatinine concentration) were severely affected. These effects were verified by histopathological examination of liver and kidney tissues. Likewise, some haematological indices (i.e. erythrocyte count, leukocyte count and haemoglobin concentration) were also influenced; in addition abamectin might cause hypoglycaemia. On the other hand, the above-mentioned lesions were less pronounced in the case of Bacillus thuringiensis -treated rats. PMID:20194097

  4. Chronic Lymphocytic Leukaemia: Census of Patients Treated in Italian Haematology Units

    PubMed Central

    Salvi, Gianfranco; Innocenti, Idanna; Autore, Francesco; Laurenti, Luca

    2015-01-01

    This study was conducted by contacting the population of the Italian haematology units and collecting from 68% of them data concerning the number of patients with chronic lymphocytic leukaemia visited over the previous 12 months, with the aim of obtaining an overview of the treatment of this disease and comparing the results with the prevalence estimates found in literature. The projection obtained (about 17,000 patients visited in the previous 12 months) is probably overestimated because of double-counting of patients who may have been treated at two different facilities during the year, although it is also underestimated since the internal medicine units were not involved. The balance of these two opposite factors is not known. It is important to bear in mind the approximation with which the count was performed in facilities for which no official data were available. Albeit with these limits, the results obtained are in line with some existing prevalence data and make it possible to determine the portion of patients at different Binet stages and in the various age ranges, identifying the corresponding therapeutic treatments. Use of the CIRS scale to classify patients as FIT and UNFIT was seen to be still somewhat limited. PMID:26543525

  5. The use of hirudin as universal anticoagulant in haematology, clinical chemistry and blood grouping.

    PubMed

    Menssen, H D; Melber, K; Brandt, N; Thiel, E

    2001-12-01

    Undesirable interactions between anticoagulants and diagnostic test kit procedures so far have prevented the development of a single uniform blood sampling tube. Contrary to K2-EDTA, heparin and other anticoagulants, hirudin only minimally alters blood cells and dissolved blood constituents, thus qualifying as a universal anticoagulant for diagnostic purposes. Automated complete blood counts, automated analyses of clinical chemistry analytes and immunohaematology were performed from hirudinised and routinely processed blood obtained from healthy volunteers (n=35) and hospitalised patients (n=45). Hirudin (400 ATU/ml blood) sufficiently anticoagulated blood for diagnostic purposes. The measurements of automated complete blood counts obtained from K2-EDTA-anticoagulated and hirudinised blood correlated significantly as did the measurements of 24 clinical chemistry analytes from hirudinised plasma and serum. Regression analysis revealed that the results of complete blood counts and clinical chemistry tests were predictable from the respective measurements from hirudinised blood (p=0.001). Immunohaematological tests and cross-matching from hirudinised and native blood of the same donors gave identical results. Single clotting factors, but not global coagulation analytes, could be measured from hirudinised blood. Therefore, a universal hirudin-containing blood sampling tube could be designed for automated analysis of haematological, serological and clinical chemistry analytes. PMID:11798089

  6. Prenatal ultrasound heating impacts on fluctuations in haematological analysis of Oryctolagus cuniculus

    PubMed Central

    Md. Dom, Sulaiman; Abdul Razak, Hairil Rashmizal; Hassan, Hamzah Fansuri

    2013-01-01

    Prenatal Ultrasound (US) is commonly used as a routine procedure on pregnant women. It is generally perceived as a safe procedure due to the use of non-ionizing radiation. However, the neurotoxicity of diagnostic prenatal US was detected to have a correlation with high susceptibility to early developing fetus. This research involved in vivo experimental model by using 3rd trimester pregnant Oryctolagus cuniculus and exposing them to US exposures for 30, 60, and 90 minutes at their gestational day (GD) 28-29. The output power and intensities, spatial peak temporal average intensity (ISPTA) of US were varied from 0.4 to 0.7 W and 0.13 to 0.19 W/cm2 respectively were tested initially in free-field, water. Haematological analysis was carried out to detect any changes in blood constituents. Statistically significant differences were detected in red blood cell (RBC) count (P<0.001), haemoglobin (Hb) concentration (P<0.001) and also platelet (PLT) count (P<0.001) in newborn of Oryctolagus cuniculus. These findings indicate the possibility of US heating in causing defects on studied animal. PMID:24273744

  7. The psychosocial experience of adolescents with haematological malignancies in Jordan: an interpretive phenomenological analysis study.

    PubMed

    Al Omari, Omar; Wynaden, Dianne

    2014-01-01

    The qualitative research method of interpretive phenomenological analysis was used to explore the lived experience of 14 Jordanian adolescents with haematological malignancies. They were admitted to two hospitals in Jordan and were interviewed for this study twice during the first six months after receiving their diagnosis. The results of this study revealed three themes: (1) Being in hospital, (2) The changing self, and (3) Fearing the unknown. When the participants were hospitalised due to their illness they were removed from their families and friends and prevented from engaging in their normal daily routine. Participants also reported receiving limited emotional and psychological support from health team members during hospitalisation. From the onset of cancer treatments, the bio-psychosocial side effects of the chemotherapy became one of the most distressing factors for participants affecting all aspects of their life and generated uncertainty about their future. The findings add to existing understanding of the lived experiences of cancer patients and in particular Jordanian adolescents. They provide a valuable insight for clinicians into improvements in service delivery to this group of patients. PMID:24550700

  8. Basic haematological values in antelopes--II. The Hippotraginae and the Tragelaphinae.

    PubMed

    Pospísil, J; Kase, F; Vahala, J; Mouchová, I

    1984-01-01

    Basic haematological values in 49 animals of five species of the subfamily Hippotraginae, namely the roan antelope Hippotragus equinus, sable antelope Hippotragus niger, adax antelope Addax nasomaculatus, gemsbok oryx Oryx gazella gazella and scimitar horned oryx Oryx damah and in 51 individuals of five species in the subfamily Tragelaphinae, including the bushbuck Tragelaphus scriptus, nyala Tragelaphus angasi, greater kudu Tragelaphus strepsiceros, cape eland Tautotragus oryx and bongo Bocercus euryceros are reported. The erythrocyte counts were in the range of 12.62 X 10(12)/l in the gemsbok oryx to 6.44 X 10(12)/l in the bongo, the haematocrit values varied from 0.488 in the nyala to 0.380 in the roan antelope and for the haemoglobin highest levels (164.0 g/l) were noted in the adax antelope, and the lowest (105.5 g/l) in the bongo. Leukocyte counts were found mostly in the normal human range and varied from 7.17 X 10(9)/l in the adax antelope to 4.05 X 10(9)/l in the nyala, only in the greater kudu decreased values of 3.02 X 10(9) were estimated. These results are compared with findings taken from the literature, and with the normal human range. PMID:6149054

  9. [Inclusion Body Disease (IBD of Boids)--a haematological, histological and electron microscopical study].

    PubMed

    Keilwerth, Melanie; Bühler, Ilina; Hoffmann, Rudolf; Soliman, Hatem; El-Matbouli, Mansour

    2012-01-01

    Our objective was to evaluate diagnostic tools for the detection of Inclusion Body Disease (IBD) in bold snakes. The aetiology of IBD is unknown, and the disease has non-specific clinical signs, hence there is a need for a clinically-applicable, specific diagnostic method. We examined blood smears and liver biopsies from 26 bold snakes (17 boas and nine pythons; some of which were suspected of having IBD) for the presence of characteristic inclusion bodies. We used haematology, histology and electron microscopy to characterise samples as IBD-positive or -negative. Our results indicate that examination of a simple blood smear is sufficient to diagnose IBD in boas. Inclusion bodies in lymphocytes, erythrocytes and thrombocytes were observed. In both, boas and pythons, we detected inclusion bodies within hepatocytes. We demonstrated also that IBD was more common in boas than in pythons: only samples from two Ball Pythons (Python regius) tested positive, whereas no other Pythonidae were positive. We consider that blood smears represents a rapid, non-invasive technique for detection of IBD. PMID:23045804

  10. Chronic diclofenac (DCF) exposure alters both enzymatic and haematological profile of African catfish, Clarias gariepinus.

    PubMed

    Ajima, Malachy N O; Ogo, Ogo A; Audu, Bala S; Ugwoegbu, Kyrian C

    2015-10-01

    Pharmaceuticals are used extensively in human and veterinary medicine to eradicate or prevent diseases. The residues of these drugs have been detected in aquatic ecosystem; nevertheless, their toxicological effects on Clarias gariepinus have not been critically investigated. In this study, the toxic effects of diclofenac (DCF), a non-steroid anti-inflammatory drug, were studied in C. gariepinus by acute and chronic static renewable bioassay. The 96 h LC50 of DCF to C. gariepinus was 25.12 mg/L. Exposure to acute toxicity resulted in abnormal behavior and mortality of some fish. Compared with the control, chronic exposure of the fish to concentration (1.57, 3.14 and 6.28 mg/L) showed significantly higher mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV) and white blood cell (WBC), with significantly lower haemoglobin (Hb), haematocrit, red blood cell (RBC) and mean corpuscular haemoglobin (MCH) with increase in the concentration of the drug. Furthermore, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and glucose values significantly increased while protein levels were reduced (p < 0.05) in serum and gills throughout the 42-day exposure period. The study reports that DCF-induced enzymatic and haematological changes in the fish and recommends that these parameters be used as potential biomarkers for assessing residual pharmaceuticals available in aquatic ecosystem. PMID:25367777

  11. Pregnancy-specific reference ranges for haematological variables in a Scottish population.

    PubMed

    Shields, R C; Caric, V; Hair, M; Jones, O; Wark, L; McColl, M D; Ramsay, J E

    2011-05-01

    Using laboratory reference ranges, B₁₂ deficiency is inappropriately diagnosed and treated in pregnancy. We aim to define reference ranges for ferritin, folate, haemoglobin and B₁₂ in a pregnant population with advancing gestation. A total of 190 women participated in a cross-sectional study, 113 in the 1st and 77 in the 3rd trimester. All variables studied except red cell folate, decreased significantly from the 1st to the 3rd trimester. A total of 34% (64/190) of women were found to have 'low' B₁₂ as defined by traditional ranges. In women with anaemia and apparent B₁₂ deficiency, co-existing ferritin deficiency was demonstrated. All women with 'low' B₁₂ levels were invited to attend postnatally for re-testing. A total of 28% (18/64) attended, in whom all B₁₂ levels spontaneously increased. The use of gestation specific reference ranges for haematological variables may reduce inappropriate diagnosis of B₁₂ deficiency. In most women with apparent low B₁₂ levels and anaemia, ferritin deficiency was demonstrated. Therefore iron should be the initial management therapy. PMID:21534746

  12. Chronic Lymphocytic Leukaemia: Census of Patients Treated in Italian Haematology Units.

    PubMed

    Salvi, Gianfranco; Innocenti, Idanna; Autore, Francesco; Laurenti, Luca

    2015-01-01

    This study was conducted by contacting the population of the Italian haematology units and collecting from 68% of them data concerning the number of patients with chronic lymphocytic leukaemia visited over the previous 12 months, with the aim of obtaining an overview of the treatment of this disease and comparing the results with the prevalence estimates found in literature. The projection obtained (about 17,000 patients visited in the previous 12 months) is probably overestimated because of double-counting of patients who may have been treated at two different facilities during the year, although it is also underestimated since the internal medicine units were not involved. The balance of these two opposite factors is not known. It is important to bear in mind the approximation with which the count was performed in facilities for which no official data were available. Albeit with these limits, the results obtained are in line with some existing prevalence data and make it possible to determine the portion of patients at different Binet stages and in the various age ranges, identifying the corresponding therapeutic treatments. Use of the CIRS scale to classify patients as FIT and UNFIT was seen to be still somewhat limited. PMID:26543525

  13. ECIL guidelines for treatment of Pneumocystis jirovecii pneumonia in non-HIV-infected haematology patients.

    PubMed

    Maschmeyer, Georg; Helweg-Larsen, Jannik; Pagano, Livio; Robin, Christine; Cordonnier, Catherine; Schellongowski, Peter

    2016-09-01

    The initiation of systemic antimicrobial treatment of Pneumocystis jirovecii pneumonia (PCP) is triggered by clinical signs and symptoms, typical radiological and occasionally laboratory findings in patients at risk of this infection. Diagnostic proof by bronchoalveolar lavage should not delay the start of treatment. Most patients with haematological malignancies present with a severe PCP; therefore, antimicrobial therapy should be started intravenously. High-dose trimethoprim/sulfamethoxazole is the treatment of choice. In patients with documented intolerance to this regimen, the preferred alternative is the combination of primaquine plus clindamycin. Treatment success should be first evaluated after 1 week, and in case of clinical non-response, pulmonary CT scan and bronchoalveolar lavage should be repeated to look for secondary or co-infections. Treatment duration typically is 3 weeks and secondary anti-PCP prophylaxis is indicated in all patients thereafter. In patients with critical respiratory failure, non-invasive ventilation is not significantly superior to intubation and mechanical ventilation. The administration of glucocorticoids must be decided on a case-by-case basis. PMID:27550993

  14. Antifibrinolytics (lysine analogues) for the prevention of bleeding in people with haematological disorders

    PubMed Central

    Estcourt, Lise J; Desborough, Michael; Brunskill, Susan J; Doree, Carolyn; Hopewell, Sally; Murphy, Michael F; Stanworth, Simon J

    2016-01-01

    Background People with haematological disorders are frequently at risk of severe or life-threatening bleeding as a result of thrombocytopenia (reduced platelet count). This is despite the routine use of prophylactic platelet transfusions to prevent bleeding once the platelet count falls below a certain threshold. Platelet transfusions are not without risk and adverse events may be life-threatening. A possible adjunct to prophylactic platelet transfusions is the use of antifibrinolytics, specifically the lysine analogues tranexamic acid (TXA) and epsilon aminocaproic acid (EACA). This is an update of a Cochrane review first published in 2013. Objectives To determine the efficacy and safety of antifibrinolytics (lysine analogues) in preventing bleeding in people with haematological disorders. Search methods We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (The Cochrane Library 2016, Issue 3), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950) and ongoing trial databases to 07 March 2016. Selection criteria We included RCTs involving participants with haematological disorders, who would routinely require prophylactic platelet transfusions to prevent bleeding. We only included trials involving the use of the lysine analogues TXA and EACA. Data collection and analysis Two review authors independently screened all electronically-derived citations and abstracts of papers, identified by the review search strategy, for relevancy. Two review authors independently assessed the full text of all potentially relevant trials for eligibility, completed the data extraction and assessed the studies for risk of bias using The Cochrane Collaboration’s ‘Risk of bias’ tool. We requested missing data from one author but the data were no longer available. The outcomes are reported narratively: we performed no meta-analyses because of the heterogeneity of the available data

  15. Effect of ceftazidime and gentamicin on the oropharyngeal and faecal flora of patients with haematological malignancies.

    PubMed

    Murdoch, D A; Gibbs, S; Price, C G; Easmon, S; Franklin, J; Lister, T A; Tabaqchali, S

    1990-09-01

    Thirty-four patients with haematological malignancies were studied to investigate the effect of empirical broad-spectrum antibiotic therapy (ceftazidime and gentamicin) on the gastro-intestinal flora. Twenty-five patients with acute myeloid leukaemia or post-autologous bone-marrow transplantation were given framycetin, nystatin and colistin (Fracon), and two patients with non-Hodgkin's Lymphoma were on co-trimoxazole, as long-term gut prophylaxis. Semi-quantitative microbiology was carried out on oropharyngeal swabs and quantitative microbiology on faecal specimens. The oropharyngeal flora consisted mainly of streptococci, coagulase-negative staphylococci and coryneforms, and was little affected by ceftazidime/gentamicin. A strain of Enterobacter cloacae resistant to ceftazidime and gentamicin colonized one patient, who later developed septicaemia. The faecal flora of patients on Fracon was dominated by enterococci; the few enterobacteria present were eliminated by ceftazidime/gentamicin. The anaerobic flora was absent in 15% of patients; in the remainder, it consisted mainly of Bacteroides spp., and was little affected by ceftazidime/gentamicin. The faecal flora of patients not on Fracon always contained anaerobes, and some strains of enterobacteria persisted throughout antibiotic treatment. None of the patients was colonized by Clostridium difficile or Pseudomonas aeruginosa. Broad-spectrum therapy with ceftazidime and gentamicin appeared to have little effect on the gastro-intestinal flora, except to encourage the overgrowth of enterococci and reduce the numbers of enterobacteria. PMID:2228830

  16. The Psychosocial Experience of Adolescents with Haematological Malignancies in Jordan: An Interpretive Phenomenological Analysis Study

    PubMed Central

    2014-01-01

    The qualitative research method of interpretive phenomenological analysis was used to explore the lived experience of 14 Jordanian adolescents with haematological malignancies. They were admitted to two hospitals in Jordan and were interviewed for this study twice during the first six months after receiving their diagnosis. The results of this study revealed three themes: (1) Being in hospital, (2) The changing self, and (3) Fearing the unknown. When the participants were hospitalised due to their illness they were removed from their families and friends and prevented from engaging in their normal daily routine. Participants also reported receiving limited emotional and psychological support from health team members during hospitalisation. From the onset of cancer treatments, the bio-psychosocial side effects of the chemotherapy became one of the most distressing factors for participants affecting all aspects of their life and generated uncertainty about their future. The findings add to existing understanding of the lived experiences of cancer patients and in particular Jordanian adolescents. They provide a valuable insight for clinicians into improvements in service delivery to this group of patients. PMID:24550700

  17. Effect of aerobic exercise on premenstrual symptoms, haematological and hormonal parameters in young women.

    PubMed

    El-Lithy, A; El-Mazny, A; Sabbour, A; El-Deeb, A

    2015-05-01

    The objective of this study was to investigate the effect of aerobic exercise on premenstrual symptoms, haematological and hormonal parameters in young women. A total of 30 participants aged 16-20 years and complaining of premenstrual syndrome (PMS) were randomly assigned into two groups: a control group received vitamin B6 and Ca supplements once daily and a study group received the same medical treatment and participated in treadmill training three times per week for 3 months. A premenstrual syndrome questionnaire (MSQ), complete blood picture and hormone assays were performed for the assessment of all participants at the start and after the end of the treatment course. The study group showed a significant decrease in all post-treatment subscale symptoms, scores and total score. Haemoglobin, haematocrit, red cell count and platelet count were significantly increased, while mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and white blood cell count showed no significant differences. There was also a significant decrease in prolactin, oestradiol and progesterone levels. In conclusion, aerobic exercise increases haemoglobin, haematocrit, red cell count and platelet count, and decreases levels of prolactin, oestradiol and progesterone, resulting in improvement of fatigue, impaired concentration, confusion and most premenstrual symptoms. PMID:25279689

  18. The effect of a Ta oxygen scavenger layer on HfO2-based resistive switching behavior: thermodynamic stability, electronic structure, and low-bias transport.

    PubMed

    Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; Nakamura, Hisao; Asai, Yoshihiro; Heinonen, Olle

    2016-03-14

    Reversible resistive switching between high-resistance and low-resistance states in metal-oxide-metal heterostructures makes them very interesting for applications in random access memories. While recent experimental work has shown that inserting a metallic "oxygen scavenger layer" between the positive electrode and oxide improves device performance, the fundamental understanding of how the scavenger layer modifies the heterostructure properties is lacking. We use density functional theory to calculate thermodynamic properties and conductance of TiN/HfO2/TiN heterostructures with and without a Ta scavenger layer. First, we show that Ta insertion lowers the formation energy of low-resistance states. Second, while the Ta scavenger layer reduces the Schottky barrier height in the high-resistance state by modifying the interface charge at the oxide-electrode interface, the heterostructure maintains a high resistance ratio between high- and low-resistance states. Finally, we show that the low-bias conductance of device on-states becomes much less sensitive to the spatial distribution of oxygen removed from the HfO2 in the presence of the Ta layer. By providing a fundamental understanding of the observed improvements with scavenger layers, we open a path to engineer interfaces with oxygen scavenger layers to control and enhance device performance. In turn, this may enable the realization of a non-volatile low-power memory technology with concomitant reduction in energy consumption by consumer electronics and offering significant benefits to society. PMID:26902598

  19. Oxygen therapy and intraocular oxygenation.

    PubMed Central

    Jampol, L M

    1987-01-01

    When delivered to the corneal surface of rabbits or monkeys, 100% oxygen can significantly increase the pO2 in the aqueous humor. Under hyperbaric conditions (two atmospheres), an observed rise in the aqueous pO2 in rabbits breathing room air can be increased further by exposing the rabbit cornea to 100% oxygen. The high oxygen levels under hyperbaric conditions are mediated by intravascular and transcorneal delivery of oxygen. The increase in the pO2 levels in the aqueous can prevent sickling of intracameral human erythrocytes containing sickle hemoglobin. Thus, oxygen therapy transcorneally or systemically could potentially be used to treat a sickle cell hyphema. The exposure of rabbit eyes to 100% oxygen at the corneal surface is followed by autoregulation (constriction) of the iris vasculature. We could demonstrate no constriction in the eyes of two normal human volunteers or of four patients with chronic stable rubeosis iridis. Preretinal vitreous pO2 levels can be significantly raised by exposing monkeys to hyperbaric 100% oxygen. This procedure may be of value in treating acute, reversible ischemic inner retinal diseases. Transcorneal or vascular delivery of oxygen to the eye under normobaric or hyperbaric conditions may be effective in treating ischemic diseases of the anterior segment, such as anterior segment necrosis or rubeosis iridis, or ischemic inner retinal diseases. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 B FIGURE 5 C FIGURE 5 A FIGURE 6 PMID:3447339

  20. Iron transport across the skin and gut epithelia of Pacific hagfish: Kinetic characterisation and effect of hypoxia.

    PubMed

    Glover, Chris N; Niyogi, Som; Blewett, Tamzin A; Wood, Chris M

    2016-09-01

    In most animals, the acquisition of the essential trace metal iron (Fe) is achieved by the gut, but in hagfishes, the skin is a nutrient absorbing epithelium, and thus may also play a role in Fe uptake. In the current study, the absorption of Fe, as Fe(II), across the intestinal and cutaneous epithelia of Pacific hagfish (Eptatretus cirrhatus) was investigated. Both epithelia absorbed Fe, with saturation at lower tested concentrations, superseded by a diffusive component at higher Fe exposure concentrations. Affinity constants (Km) of 9.4 and 137μM, and maximal Fe transport rates (Jmax) of 0.81 and 0.57nmolcm(-2)h(-1) were determined for the skin and the gut, respectively. This characterises the skin as a relatively high-affinity Fe transport epithelium. The majority of the absorbed Fe in the skin remained in the tissue, whereas in the gut, most absorbed Fe was found in the serosal fluid, suggesting distinct mechanisms of Fe handling between the two epithelia. To determine if reduced dissolved oxygen altered Fe transport, hagfish were subjected to hypoxia for 24h, before Fe transport was again assessed. Hypoxia had no effect on Fe transport across gut or skin, likely owing to the relative lack of change in haematological variables, and thus an unaltered Fe demand under such conditions. These data are the first to kinetically characterise the absorption of a nutritive trace metal across the epithelia of hagfish and add to the growing understanding of the role of the skin in nutritive transport in this group. PMID:27112517

  1. Outgassing of oxygen from polycarbonate.

    PubMed

    Moon, Sung In; Monson, L; Extrand, C W

    2009-07-01

    A manometric permeation apparatus was used to study the "outgassing" or desorption of oxygen from polycarbonate (PC). A PC film was placed in the apparatus. Both sides were exposed to oxygen until the film was saturated. To simulate inert gas purging of a closed container or "microenvironment", oxygen was pumped from one side of the apparatus to reduce the concentration on that side to nearly zero. Oxygen concentrations on the freshly purged side rose quickly at first but then slowed. Eventually, a steady state was established and oxygen concentrations increased linearly with time. Mass-transport coefficients (permeation, diffusion, and solubility coefficients) were also estimated and then used to successfully predict the postpurge rise of the oxygen concentration. PMID:20355958

  2. Oxygen gradients in the microcirculation.

    PubMed

    Pittman, R N

    2011-07-01

    Early in the last century August Krogh embarked on a series of seminal studies to understand the connection between tissue metabolism and mechanisms by which the cardiovascular system supplied oxygen to meet those needs. Krogh recognized that oxygen was supplied from blood to the tissues by passive diffusion and that the most likely site for oxygen exchange was the capillary network. Studies of tissue oxygen consumption and diffusion coefficient, coupled with anatomical studies of capillarity in various tissues, led him to formulate a model of oxygen diffusion from a single capillary. Fifty years after the publication of this work, new methods were developed which allowed the direct measurement of oxygen in and around microvessels. These direct measurements have confirmed the predictions by Krogh and have led to extensions of his ideas resulting in our current understanding of oxygenation within the microcirculation. Developments during the last 40 years are reviewed, including studies of oxygen gradients in arterioles, capillaries, venules, microvessel wall and surrounding tissue. These measurements were made possible by the development and use of new methods to investigate oxygen in the microcirculation, so mention is made of oxygen microelectrodes, microspectrophotometry of haemoglobin and phosphorescence quenching microscopy. Our understanding of oxygen transport from the perspective of the microcirculation has gone from a consideration of oxygen gradients in capillaries and tissue to the realization that oxygen has the ability to diffuse from any microvessel to another location under the conditions that there exists a large enough PO(2) gradient and that the permeability for oxygen along the intervening pathway is sufficient. PMID:21281453

  3. Providing Pressurized Gasses to the International Space Station (ISS): Developing a Composite Overwrapped Pressure Vessel (COPV) for the Safe Transport of Oxygen and Nitrogen

    NASA Technical Reports Server (NTRS)

    Kezirian, Michael; Cook, Anthony; Dick, Brandon; Phoenix, S. Leigh

    2012-01-01

    To supply oxygen and nitrogen to the International Space Station, a COPV tank is being developed to meet requirements beyond that which have been flown. In order to "Ship Full' and support compatibility with a range of launch site operations, the vessel was designed for certification to International Standards (ISO) that have a different approach than current NASA certification approaches. These requirements were in addition to existing NASA certification standards had to be met. Initial risk-reduction development tests have been successful. Qualification is in progress.

  4. Studies of Transport Properties and Critical Temperature Suppression Mechanism in Yttrium BARIUM(2) COPPER(3) Oxygen(x) Thin Films Irradiated with 20 TO 120 KEV Electrons

    NASA Astrophysics Data System (ADS)

    Lin, Jiunn-Yuan

    1995-11-01

    We present comprehensive studies of the effects of 20 to 120 keV electron irradiation on rm YBa_2Cu_3O_{x} thin films. Above 60 keV, T_{c } of irradiated samples is suppressed accompanied by a significant increase in residual resistivity, while the carrier concentration remains relatively unchanged. The plane oxygen defects produced by irradiation are found to be responsible for T_{c} suppression. The II suppression mechanism is discussed within several theoretical frameworks. Though in qualitative agreement with d-wave pairing symmetry, our results show a T_{c} suppression rate three times as slow as predicted by the theory when resistivity data are used to extract the impurity scattering rate. Alternatively, phase fluctuations theory gives a qualitative description as well. The displacement energy of plane oxygen is found to be 8.3 eV, which corresponds to a threshold electron energy 58 keV. Finally, an empirical relation is proposed to describe the temperature dependence of the Hall coefficient.

  5. Detection of invasive pulmonary aspergillosis in haematological malignancy patients by using lateral-flow technology.

    PubMed

    Thornton, Christopher; Johnson, Gemma; Agrawal, Samir

    2012-01-01

    Invasive pulmonary aspergillosis (IPA) is a leading cause of morbidity and mortality in haematological malignancy patients and hematopoietic stem cell transplant recipients(1). Detection of IPA represents a formidable diagnostic challenge and, in the absence of a 'gold standard', relies on a combination of clinical data and microbiology and histopathology where feasible. Diagnosis of IPA must conform to the European Organization for Research and Treatment of Cancer and the National Institute of Allergy and Infectious Diseases Mycology Study Group (EORTC/MSG) consensus defining "proven", "probable", and "possible" invasive fungal diseases(2). Currently, no nucleic acid-based tests have been externally validated for IPA detection and so polymerase chain reaction (PCR) is not included in current EORTC/MSG diagnostic criteria. Identification of Aspergillus in histological sections is problematic because of similarities in hyphal morphologies with other invasive fungal pathogens(3), and proven identification requires isolation of the etiologic agent in pure culture. Culture-based approaches rely on the availability of biopsy samples, but these are not always accessible in sick patients, and do not always yield viable propagules for culture when obtained. An important feature in the pathogenesis of Aspergillus is angio-invasion, a trait that provides opportunities to track the fungus immunologically using tests that detect characteristic antigenic signatures molecules in serum and bronchoalveolar lavage (BAL) fluids. This has led to the development of the Platelia enzyme immunoassay (GM-EIA) that detects Aspergillus galactomannan and a 'pan-fungal' assay (Fungitell test) that detects the conserved fungal cell wall component (1 →3)-β-D-glucan, but not in the mucorales that lack this component in their cell walls(1,4). Issues surrounding the accuracy of these tests(1,4-6) has led to the recent development of next-generation monoclonal antibody (MAb)-based assays that

  6. Detection of Invasive Pulmonary Aspergillosis in Haematological Malignancy Patients by using Lateral-flow Technology

    PubMed Central

    Thornton, Christopher; Johnson, Gemma; Agrawal, Samir

    2012-01-01

    Invasive pulmonary aspergillosis (IPA) is a leading cause of morbidity and mortality in haematological malignancy patients and hematopoietic stem cell transplant recipients1. Detection of IPA represents a formidable diagnostic challenge and, in the absence of a 'gold standard', relies on a combination of clinical data and microbiology and histopathology where feasible. Diagnosis of IPA must conform to the European Organization for Research and Treatment of Cancer and the National Institute of Allergy and Infectious Diseases Mycology Study Group (EORTC/MSG) consensus defining "proven", "probable", and "possible" invasive fungal diseases2. Currently, no nucleic acid-based tests have been externally validated for IPA detection and so polymerase chain reaction (PCR) is not included in current EORTC/MSG diagnostic criteria. Identification of Aspergillus in histological sections is problematic because of similarities in hyphal morphologies with other invasive fungal pathogens3, and proven identification requires isolation of the etiologic agent in pure culture. Culture-based approaches rely on the availability of biopsy samples, but these are not always accessible in sick patients, and do not always yield viable propagules for culture when obtained. An important feature in the pathogenesis of Aspergillus is angio-invasion, a trait that provides opportunities to track the fungus immunologically using tests that detect characteristic antigenic signatures molecules in serum and bronchoalveolar lavage (BAL) fluids. This has led to the development of the Platelia enzyme immunoassay (GM-EIA) that detects Aspergillus galactomannan and a 'pan-fungal' assay (Fungitell test) that detects the conserved fungal cell wall component (1 →3)-β-D-glucan, but not in the mucorales that lack this component in their cell walls1,4. Issues surrounding the accuracy of these tests1,4-6 has led to the recent development of next-generation monoclonal antibody (MAb)-based assays that detect

  7. Implementation of monoclonal antibody fluorescence on the Abbott CELL-DYN Sapphire haematology analyser: evaluation of lymphoid, myeloid and platelet markers.

    PubMed

    Johannessen, B; Roemer, B; Flatmoen, L; Just, T; Aarsand, A K; Scott, C S

    2006-04-01

    Apart from qualitative flags, that are typically inefficient and uninformative, haematology instruments provide little meaningful information about lymphocyte populations or the lineage of atypical or immature elements, The CELL-DYN Sapphire haematology analyser uses integrated optical and fluorescence (488 nm) measurements, with FL1 (FITC) and FL2 (PE) detectors being configured for fluorescent analysis. As monoclonal antibodies (Mab) are widely used as cellular probes, and are likely to constitute the future basis for immunodifferentials, we explored the feasibility of implementing immunofluorescence on this routine haematology analyser. An extensive series of Mab (CD2, CD3, CD4, CD8, CD11b, CD13, CD14, CD16, CD19, CD22, CD33, CD34, CD41, CD42b, CD45, CD56, CD61, CD64, CD235a and HLA-DR) were tested singly or in FITC/PE combinations. Analyser processing and data acquisition was achieved using CD-Sapphire automated CD61 immunoplatelet or CD3/4/8 assay procedures and, apart from mixing EDTA-blood and antibody, no further sample manipulation was required. Downloaded raw files were processed with cytometry software, and all evaluated reagents showed population discrimination analogous to flow cytometry. Practical procedures were straightforward and required minimal operator training. Extended information that can be obtained from monoclonal antibodies with a routine haematology analyser has the potential to extend haematology laboratory practices and positively impact laboratory and clinical efficiency. PMID:16630212

  8. Haematological malignancies and acute kidney injury requiring nephrology consultation: challenging the worst of the worst

    PubMed Central

    Chuva, Teresa; Maximino, José; Barbosa, Joselina; Silva, Sandra; Paiva, Ana; Baldaia, Jorge; Loureiro, Alfredo

    2016-01-01

    Background Acute kidney injury (AKI) often complicates the course of haematological malignancies (HMs) and confers a worse prognosis. The majority of these patients are managed by the attending physician, yet, a small group, mostly coincident with the worst presentation and outcomes, requires nephrology consultation, challenging the clinician with ethical issues regarding the decision to initiate or forgo renal support therapy. The purpose of this work is to identify the prognostic determinants for in-hospital mortality in this population. Methods A retrospective, observational chart review was undertaken at a single tertiary referral oncological centre. We reviewed the medical records of in-hospital patients with AKI and HM between 1 January 1995 and 31 December 2014 who met the criteria for RIFLE (Risk, Injury, and Failure; and Loss; and End-stage kidney disease) classification of I or higher and were followed by a nephrologist. Results Three hundred and forty-five patients were included in the study. Predictors of in-hospital death in patients with HM and AKI were septic shock [odds ratio (OR) 4.290 (95% CI 2.058–8.943)], invasive mechanical ventilation (IMV) [OR 4.305 (95% CI 2.075–8.928)] and allogeneic stem cell transplantation (SCT) [OR 2.232 (95% CI 1.260–3.953)]. The combination of each risk factor was used to estimate the probability of dying. Patients with all three risk factors had a risk of death of 86%. Conclusions Septic shock, IMV and allogeneic SCT were identified as independent predictors of death in patients with HM and AKI, with only a small chance of survival if all three were present. Depending on the combination of risk factors, the indication for aggressive life support therapies, such as RST, might be questionable. PMID:27274827

  9. Relevance of Haematologic Parameters in Obese Women with or without Metabolic Syndrome

    PubMed Central

    Raghavan, Vijayashree; Gunasekar, Damini

    2016-01-01

    Introduction Obesity is rapidly growing problem worldwide. It predisposes to a variety of serious ailments including heart disease, diabetes mellitus, degenerative joint disease, atherosclerosis, etc. This is probably related to proinflammatory state associated with obesity due to release of several inflammatory mediators by the adipose tissue. The mediators are also probably responsible for metabolic syndrome associated with obesity. Besides, they may also induce significant changes in haematological parameters associated with inflammation. Aim Present study was undertaken to ascertain the relationship between obesity and leucocyte counts (particularly TLC and ANC) and find out if the changes induced in them are significant enough to be used as predictors of metabolic syndrome. Materials and Methods This case-control study was carried out on 243 female subjects allocated to four groups based on WHO and IDF criteria: Control, Overweight, Obese and Obese with Metabolic Syndrome. From all the subjects, data pertaining to obesity related anthropometric measurements, lipid profile, fasting plasma glucose levels and complete blood counts were collected. These were analysed statistically. Results There was a strong positive correlation between obesity related anthropometric measurements (BMI, BF, WC) and leucocyte counts – TLC and ANC – which were statistically highly significant; TNC and ANC also showed strong positive correlation with FPG. Mean values for TLC and ANC showed statistically significant difference between each and every group. The difference in the mean values of these parameters between obese and metabolic syndrome was highly significant. Both elevated FPG and BMI were independently associated with relative leucocytosis; when both of them were elevated simultaneously, the effect appeared to be potentiating. Conclusion Increase in obesity associated anthropometric measurements (BMI, WC, BF) is associated with relative leucocytosis within the

  10. Comparison of respiratory virus shedding by conventional and molecular testing methods in patients with haematological malignancy

    PubMed Central

    Richardson, L.; Brite, J.; Del Castillo, M.; Childers, T.; Sheahan, A.; Huang, Y-T.; Dougherty, E.; Babady, NE.; Sepkowitz, K.; Kamboj, M.

    2016-01-01

    Respiratory viruses (RV) are a leading cause of infection-related morbidity and mortality for patients undergoing treatment for cancer. This analysis compared duration of RV shedding as detected by culture and PCR among patients in a high-risk oncology setting (adult patients with haematological malignancy and/or stem cell transplant and all paediatric oncology patients) and determined risk factors for extended shedding. RV infections due to influenza virus, parainfluenza virus (PIV), human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) from two study periods—January 2009–September 2011 (culture-based testing) and September 2011–April 2013 (PCR-based testing)—were reviewed retrospectively. Data were collected from patients in whom re-testing for viral clearance was carried out within 5–30 days after the most recent test. During the study period 456 patients were diagnosed with RV infection, 265 by PCR and 191 by culture. The median range for duration of shedding (days) by culture and PCR, respectively, were as follows—influenza virus: 13 days (5–38 days) versus 14 days (5–58 days), p 0.5; RSV: 11 days (5–35 days) versus 16 days (5–50 days), p 0.001; PIV: 9 days (5–41 days) versus 17 days (5–45 days), p ≤0.0001; HMPV 10.5 days (5–29 days) versus 14 days (5–42 days), p 0.2. In multivariable analysis, age and underlying disease or transplant were not independently associated with extended shedding regardless of testing method. In high-risk oncology settings for respiratory illness due to RSV and PIV, the virus is detectable by PCR for a longer period of time than by culture and extended shedding is observed. PMID:26711433

  11. Haematological validation of a computer-based bone marrow reporting system.

    PubMed Central

    Nguyen, D T; Diamond, L W; Cavenagh, J D; Parameswaran, R; Amess, J A

    1997-01-01

    AIMS: To prove the safety and effectiveness of "Professor Belmonte", a knowledge-based system for bone marrow reporting, a formal evaluation of the reports generated by the system was performed. METHODS: Three haematologists (a consultant, a senior registrar, and a junior registrar), none of whom were involved in the development of the software, compared the unedited reports generated by Professor Belmonte with the original bone marrow reports in 785 unselected cases. Each haematologist independently graded the quality of Belmonte's reports using one of four categories: (a) better than the original report (more informative, containing useful information missing in the original report); (b) equivalent to the original report; (c) satisfactory, but missing information that should have been included; and (d) unsatisfactory. RESULTS: The consultant graded 64 reports as more informative than the original, 687 as equivalent to the original, 32 as satisfactory, and two as unsatisfactory. The senior registrar considered 29 reports to be better than the original, 739 to be equivalent to the original, 15 to be satisfactory, and two to be unsatisfactory. The junior registrar found that 88 reports were better than the original, 681 were equivalent to the original, 14 were satisfactory, and two were unsatisfactory. Each judge found two different reports to be unsatisfactory according to their criteria. All 785 reports generated by the computer system received at least two scores of satisfactory or better. CONCLUSIONS: In this representative study, Professor Belmonte generated bone marrow reports that proved to be as accurate as the original reports in a large university hospital. The haematology knowledge contained within the system, the reasoning process, and the function of the software are safe and effective for assisting haematologists in generating high quality bone marrow reports. PMID:9215118

  12. Haematological and ion regulatory effects of nitrite in the air-breathing snakehead fish Channa striata.

    PubMed

    Lefevre, Sjannie; Jensen, Frank B; Huong, Do T T; Wang, Tobias; Phuong, Nguyen T; Bayley, Mark

    2012-08-15

    The tolerance and effects of nitrite on ion balance and haematology were investigated in the striped snakehead, Channa striata Bloch 1793, which is an air-breathing fish with reduced gills of importance for aquaculture in South East Asia. C. striata was nitrite tolerant with a 96 h LC50 of 4.7 mM. Effects of sub-lethal exposures to nitrite (0mM, 1.4mM, and 3.0mM) were determined during a 7-day exposure period. Plasma nitrite increased, but the internal concentration remained well below ambient levels. Extracellular nitrate rose by several mM, indicating that a large proportion of the nitrite taken up was converted to nitrate. Nitrite reacted with erythrocyte haemoglobin (Hb) causing methaemoglobin (metHb) to increase to 30% and nitrosylhaemoglobin (HbNO) to increase to 10% of total Hb. Both metHb and HbNO stabilised after 4 days, and functional Hb levels accordingly never fell below 60% of total Hb. Haematocrit and total Hb were unaffected by nitrite. Although the effects of nitrite exposure seemed minor in terms of plasma nitrite and metHb increases, ion balance was strongly affected. In the high exposure group, total osmolality decreased from 320 mOsm to 260 mOsm, and plasma sodium from 150 mM to 120 mM, while plasma chloride fell from 105 mM to 60mM and plasma bicarbonate rose from 12 mM in controls to 20mM in exposed fish. The extreme changes in ion balance in C. striata are different from the response reported in other fish, and further studies are needed to investigate the mechanism behind the observed changes in regulation. PMID:22516674

  13. Changes in interfacial potentials induced by carbonylcyanide phenylhydrazone uncouplers: possible role in inhibition of mitochondrial oxygen consumption and other transport processes.

    PubMed

    Reyes, J; Benos, D J

    1984-01-01

    The charged and uncharged forms of carbonylcyanide phenylhydrazone uncouplers bind to phosphatidylcholine monolayers in a dose-dependent fashion, inducing changes in the interfacial potential of these model membranes. The interfacial potential change produced by the charged uncoupler is composed of a double-layer potential and an internal electrostatic potential (boundary and/or dipole). Changes in double-layer potential induced by the uncouplers in mitochondrial membranes can explain both the inhibition of oxygen consumption (QO2) caused by the uncouplers and the competition shown by succinate when mitochondria are respiring in the presence of rotenone. From these results and from dose-response curves of QO2 versus uncoupler concentrations, we conclude that 1 microM is an upper limit for free uncoupler concentration in the medium to avoid unwanted side effects during cell physiology studies that require total mitochondrial uncoupling. PMID:6748952

  14. Monoclonal antibody fluorescence for routine lymphocyte subpopulation analysis with the Abbott CELL-DYN Sapphire haematology analyser.

    PubMed

    Molero, T; Lemes, A; DE LA Iglesia, S; Scott, C S

    2007-12-01

    Using previously described procedures, this study quantified T-cell, T-cell subset, B-cell and NK-cell populations with the CD-Sapphire haematology analyser in a series of patients with mild to moderate lymphocytosis. Lymphocyte counts ranged from 6.0 to 14.9 x 10(9)/l, with 86/97 being <10.0 x 10(9)/l. Immunophenotyping (CD3/CD19/HLA-DR, CD4/CD8 and CD16/CD56 combinations) was performed using EDTA-anticoagulated blood, automated CD-Sapphire analysis and subsequent software processing. Of 35 samples from younger (<12 years) patients, 22 (63%) had nonspecific lymphocyte changes, 4 (11%) showed specific increases in nonreactive T-Helper or T-Suppressor cells, and five showed a reactive T-cell lymphocytosis. The remaining four were classified as 'Transient/Persistent NK-associated (NKa) Expansion' (n = 3) and specific B-cell lymphocytosis (n = 1). For older patients (n = 59), 15 (25%) had an increase (>1.5 x 10(9)/l) in B-cells, and seven investigated for surface immunoglobulin expression were all found to be clonal. The remaining samples were categorized as 'Transient/Persistent NK-associated (NKa) Expansion' (13/59), Reactive Lymphocytosis (5/59), 'Reactive Lymphocytosis or Transient/Persistent NKa Expansion' (8/59), specific T-Helper cell (n = 8) or T-Suppressor cell (n = 3) lymphocytosis, and 'Lymphocytosis of Undetermined Significance' (n = 7). This study has demonstrated the feasibility of applying limited immunophenotyping protocols to the investigation of patients with abnormal lymphocyte counts in routine haematology. By using commercially purchased liquid monoclonal reagents to determine lymphocyte subpopulation profiles, haematology laboratories can provide more definitive information of potential clinical importance. PMID:17988300

  15. Haematological parameters of alloxan-induced diabetic rats treated with leaf essential oil of Hoslundia opposita (Vahl)

    PubMed Central

    Muhammad, N.O.; Akolade, J.O.; Usman, L.A.; Oloyede, O.B.

    2012-01-01

    The effect of leaf essential oil of Hoslundia opposita (Vahl) on the haematological parameters of alloxan-induced diabetic rats was investigated. Forty-eight albino rats (Rattus norvegicus), of average weight 132.5 g, were randomly selected into normal and diabetic groups, each with four sub-groups. The rats were treated with 110 and 220 mg/kg body weight (b. wt.) of the essential oil. 14.2 mg/kg body weight of metformin (Glucophage) was used as a reference drug. All treatments were administered, intraperitoneally, once a day for four days. Haematological parameters like haemoglobin (HGB), red blood cell (RBC) count, white blood cell (WBC) count, percentage lymphocytes (LYM) and neutrophils (NEU) were analysed. There were no significant differences (p > 0.05) in the erythrocyte indices of all the normal (non-diabetic) rats, both treated and untreated. However, there was a significant increase (p < 0.05) in the WBC count and a significant reduction (p < 0.05) in the lymphocyte (LYM) percentages of the normal (non-diabetic) rats administered with higher dose of the essential oil. The results also revealed a significant reduction (p < 0.05) and a significant increase (p < 0.05) in the RBC counts of untreated diabetic rats and diabetic rats administered 110 mg/kg b. wt. of the oil respectively. A significant increase (p < 0.05) in the LYM of diabetic untreated rats was also observed, while administration of metformin and 110 mg/kg b. wt. Hoslundia opposita leaf essential oil (HOLEO) to diabetic rats significantly (p < 0.05) reduced the LYM percentages to values within range of the normal control animals. Overall, administration of the oil has significant ameliorative effect on alloxan-induced anaemia in diabetic state and this may be of immense benefits in the management of type 2 diabetes and its associated haematological complications.

  16. Alternative agents versus prophylactic platelet transfusion for preventing bleeding in patients with haematological disorders after chemotherapy or stem cell transplantation

    PubMed Central

    Estcourt, Lise J; Gregg, Richard; Stanworth, Simon; Doree, Carolyn; Trivella, Marialena; Murphy, Michael F; Tinmouth, Alan

    2014-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether alternative agents (e.g. artificial platelet substitutes, platelet-poor plasma, fibrinogen, rFVIIa, thrombopoietin mimetics) are as effective and safe as the use of platelet transfusions for the prevention of bleeding (prophylactic platelet transfusion) in patients with haematological disorders who are undergoing myelosuppressive chemotherapy or stem cell transplantation. Antifibrinolytics (lysine analogues) will not be included in this review because they have been the focus of another Cochrane review (Wardrop 2013). PMID:25722650

  17. Plasma Spray Physical Vapor Deposition of La1- x Sr x Co y Fe1- y O3-δ Thin-Film Oxygen Transport Membrane on Porous Metallic Supports

    NASA Astrophysics Data System (ADS)

    Jarligo, Maria Ophelia; Mauer, Georg; Bram, Martin; Baumann, Stefan; Vaßen, Robert

    2014-01-01

    Plasma spray physical vapor deposition (PS-PVD) is a very promising route to manufacture ceramic coatings, combining the efficiency of thermal spray processes and characteristic features of thin PVD coatings. Recently, this technique has been investigated to effectively deposit dense thin films of perovskites particularly with the composition of La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) for application in gas separation membranes. Furthermore, asymmetric type of membranes with porous metallic supports has also attracted research attention due to the advantage of good mechanical properties suitable for use at high temperatures and high permeation rates. In this work, both approaches are combined to manufacture oxygen transport membranes made of gastight LSCF thin film by PS-PVD on porous NiCoCrAlY metallic supports. The deposition of homogenous dense thin film is challenged by the tendency of LSCF to decompose during thermal spray processes, irregular surface profile of the porous metallic substrate and crack and pore-formation in typical ceramic thermal spray coatings. Microstructure formation and coating build-up during PS-PVD as well as the annealing behavior at different temperatures of LSCF thin films were investigated. Finally, measurements of leak rates and oxygen permeation rates at elevated temperatures show promising results for the optimized membranes.

  18. GASP: A computer code for calculating the thermodynamic and transport properties for ten fluids: Parahydrogen, helium, neon, methane, nitrogen, carbon monoxide, oxygen, fluorine, argon, and carbon dioxide. [enthalpy, entropy, thermal conductivity, and specific heat

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Baron, A. K.; Peller, I. C.

    1975-01-01

    A FORTRAN IV subprogram called GASP is discussed which calculates the thermodynamic and transport properties for 10 pure fluids: parahydrogen, helium, neon, methane, nitrogen, carbon monoxide, oxygen, fluorine, argon, and carbon dioxide. The pressure range is generally from 0.1 to 400 atmospheres (to 100 atm for helium and to 1000 atm for hydrogen). The temperature ranges are from the triple point to 300 K for neon; to 500 K for carbon monoxide, oxygen, and fluorine; to 600 K for methane and nitrogen; to 1000 K for argon and carbon dioxide; to 2000 K for hydrogen; and from 6 to 500 K for helium. GASP accepts any two of pressure, temperature and density as input conditions along with pressure, and either entropy or enthalpy. The properties available in any combination as output include temperature, density, pressure, entropy, enthalpy, specific heats, sonic velocity, viscosity, thermal conductivity, and surface tension. The subprogram design is modular so that the user can choose only those subroutines necessary to the calculations.

  19. Identifying Reactive Sites and Transport Limitations of Oxygen Reactions in Aprotic Lithium-O2 Batteries at the Stage of Sudden Death.

    PubMed

    Wang, Jiawei; Zhang, Yelong; Guo, Limin; Wang, Erkang; Peng, Zhangquan

    2016-04-18

    Discharging of the aprotic Li-O2 battery relies on the O2 reduction reaction (ORR) forming solid Li2 O2 in the positive electrode, which is often characterized by a sharp voltage drop (that is, sudden death) at the end of discharge, delivering a capacity far below its theoretical promise. Toward unlocking the energy capabilities of Li-O2 batteries, it is crucial to have a fundamental understanding of the origin of sudden death in terms of reactive sites and transport limitations. Herein, a mechanistic study is presented on a model system of Au|Li2 O2 |Li(+) electrolyte, in which the Au electrode was passivated with a thin Li2 O2 film by discharging to the state of sudden death. Direct conductivity measurement of the Li2 O2 film and in situ spectroscopic study of ORR using (18) O2 for passivation and (16) O2 for further discharging provide compelling evidence that ORR (and O2 evolution reaction as well) occurs at the buried interface of Au|Li2 O2 and is limited by electron instead of Li(+) and O2 transport. PMID:26970228

  20. Oxygen-Concentrating Cell

    NASA Technical Reports Server (NTRS)

    Buehler, K.

    1986-01-01

    High-purity oxygen produced from breathing air or from propellantgrade oxygen in oxygen-concentrating cell. Operating economics of concentrator attractive: Energy consumption about 4 Wh per liter of oxygen, slightly lower than conventional electrochemical oxygen extractors.

  1. Using oxygen at home

    MedlinePlus

    ... DO NOT use oil-based products, such as petroleum jelly (Vaseline). Ask your oxygen equipment provider about ... oxygen; Hypoxia - home oxygen; Hospice - home oxygen References American Thoracic Society. Why do I need oxygen therapy? ...

  2. Baseline plasma corticosterone, haematological and biochemical results in nesting and rehabilitating loggerhead sea turtles (Caretta caretta)

    PubMed Central

    Flower, Jennifer E.; Norton, Terry M.; Andrews, Kimberly M.; Nelson, Steven E.; Parker, Clare E.; Romero, L. Michael; Mitchell, Mark A.

    2015-01-01

    The evaluation of hormonal responses to stress in reptiles relies on acquisition of baseline corticosterone concentrations; however, the stress associated with the restraint needed to collect the blood samples can affect the results. The purpose of this study was to determine a time limit for the collection of blood samples to evaluate baseline corticosterone, haematological and biochemical results in nesting (n = 11) and rehabilitating (n = 16) loggerhead sea turtles (Caretta caretta). Blood samples were collected from the dorsal cervical sinus of each turtle immediately after touching the animal (t0; 0–3 min) and 3 (t3; 3–6 min), 6 (t6; 6–9 min; nesting turtles only), 10 (t10; 10–13 min) and 30 min (t30; rehabilitating turtles only) after the initial hands-on time. Consistent between the rehabilitating and nesting turtles, there was a subtle yet significant increase in white blood cell counts over time. Despite the fact that white blood cell counts increased during the sampling period, there was no direct correlation between white blood cell count and corticosterone in the sampled turtles. In the nesting turtles, significant elevations in corticosterone were noted between t0 and t3 (P = 0.014) and between t0 and t6 (P = 0.022). Values at t10 were not significantly different from those at t0 (P = 0.102); however, there was a trend for the corticosterone values to continue to increase. These results suggest that sampling of nesting loggerhead sea turtles within 3 min of handling will provide baseline corticosterone concentrations in their natural environment. Significant elevations in corticosterone were also noted in the rehabilitating loggerhead sea turtles between t0 and t10 (P = 0.02) and between t0 and t30 of sampling (P = 0.0001). These results suggest that sampling of loggerhead sea turtles within 6 min of handling should provide baseline corticosterone concentrations in a rehabilitation setting. The delay in

  3. Effect of recombinant human erythropoietin treatment on blood pressure and some haematological parameters in healthy men.

    PubMed

    Berglund, B; Ekblom, B

    1991-02-01

    The aim of this study was to evaluate the effect of treatment with subcutaneous injections of recombinant human erythropoietin (rhEpo), 20-40 IU kg-1 body weight, 3 times a week, on resting blood pressure, blood pressure response during submaximal exercise, some haematological parameters, and subjective side-effects in 15 healthy male subjects. RhEpo increased both haemoglobin (Hb) concentration and haematocrit (Hct) significantly, the values for Hb being 152 +/- 4.2 g l-1 before treatment and 169 +/- 9.3 g l-1 (mean values +/- SD) after 6 weeks of rhEpo treatment (P less than 0.001). The corresponding values for Hct were 44.5 +/- 1.5% and 49.7 +/- 1.9% (P less than 0.001), respectively. The systolic and diastolic blood pressure values at rest were unchanged after rhEpo treatment. A marked increase in systolic blood pressure was observed during submaximal exercise at 200 W, the initial and final values being 177 +/- 14.2 mmHg and 191 +/- 19.5 mmHg (P less than 0.01), respectively. Heart rate during exercise at 200 W was significantly lower after rhEpo treatment than before it: 144 +/- 15 beats min-1 compared to 136 +/- 8 beats min-1 (P less than 0.001). The leucocyte count remained unchanged after rhEpo treatment, but there was a significant decrease (P less than 0.05) in the number of lymphocytes. Reticulocyte and platelet counts were unchanged. Serum (S) ferritin decreased from 87.3 +/- 41.8 mmol l-1 to 59.3 +/- 27.8 mmol l-1 after rhEpo treatment (P less than 0.001). Serum-Na, S-K, S-Ca, S-creatinine, S-bilirubin, S-aspartate aminotransferase (ASAT), S-alanine aminotransferase (ALAT), and S-lactate dehydrogenase (LD) were unchanged after rhEpo treatment. No subjective side-effects were reported. In conclusion, low doses of rhEpo increased Hb levels and Hct by more than 10% after 6 weeks. Blood pressure at rest was unchanged, but rhEpo induced a markedly accentuated blood pressure reaction during exercise. A minor decrease in the lymphocyte count was observed

  4. Comparison of respiratory virus shedding by conventional and molecular testing methods in patients with haematological malignancy.

    PubMed

    Richardson, L; Brite, J; Del Castillo, M; Childers, T; Sheahan, A; Huang, Y-T; Dougherty, E; Babady, N E; Sepkowitz, K; Kamboj, M

    2016-04-01

    Respiratory viruses (RV) are a leading cause of infection-related morbidity and mortality for patients undergoing treatment for cancer. This analysis compared duration of RV shedding as detected by culture and PCR among patients in a high-risk oncology setting (adult patients with haematological malignancy and/or stem cell transplant and all paediatric oncology patients) and determined risk factors for extended shedding. RV infections due to influenza virus, parainfluenza virus (PIV), human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) from two study periods-January 2009-September 2011 (culture-based testing) and September 2011-April 2013 (PCR-based testing)-were reviewed retrospectively. Data were collected from patients in whom re-testing for viral clearance was carried out within 5-30 days after the most recent test. During the study period 456 patients were diagnosed with RV infection, 265 by PCR and 191 by culture. The median range for duration of shedding (days) by culture and PCR, respectively, were as follows-influenza virus: 13 days (5-38 days) versus 14 days (5-58 days), p 0.5; RSV: 11 days (5-35 days) versus 16 days (5-50 days), p 0.001; PIV: 9 days (5-41 days) versus 17 days (5-45 days), p ≤0.0001; HMPV 10.5 days (5-29 days) versus 14 days (5-42 days), p 0.2. In multivariable analysis, age and underlying disease or transplant were not independently associated with extended shedding regardless of testing method. In high-risk oncology settings for respiratory illness due to RSV and PIV, the virus is detectable by PCR for a longer period of time than by culture and extended shedding is observed. PMID:26711433

  5. Towards optimal clinical and epidemiological registration of haematological malignancies: Guidelines for recording progressions, transformations and multiple diagnoses.

    PubMed

    Gavin, Anna; Rous, Brian; Marcos-Gragera, Rafael; Middleton, Richard; Steliarova-Foucher, Eva; Maynadie, Marc; Zanetti, Roberto; Visser, Otto

    2015-06-01

    Haematological malignancies (HM) represent over 6% of the total cancer incidence in Europe and affect all ages, ranging between 45% of all cancers in children and 7% in the elderly. Thirty per cent of childhood cancer deaths are due to HM, 8% in the elderly. Their registration presents specific challenges, mainly because HM may transform or progress in the course of the disease into other types of HM. In the context of cancer registration decisions have to be made about classifying subsequent notifications on the same patient as the same tumour (progression), a transformation or a new tumour registration. Allocation of incidence date and method of diagnosis must also be standardised. We developed European Network of Cancer Registries (ENCR) recommendations providing specific advice for cancer registries to use haematology and molecular laboratories as data sources, conserve the original date of incidence in case of change of diagnosis, make provision for recording both the original as well as transformed tumour and to apply precise rules for recording and counting multiple diagnoses. A reference table advising on codes which reflect a potential transformation or a new tumour is included. This work will help to improve comparability of data produced by population-based cancer registries, which are indispensable for aetiological research, health care planning and clinical research, an increasing important area with the application of targeted therapies. PMID:24630945

  6. Indications for allo- and auto-SCT for haematological diseases, solid tumours and immune disorders: current practice in Europe, 2015.

    PubMed

    Sureda, A; Bader, P; Cesaro, S; Dreger, P; Duarte, R F; Dufour, C; Falkenburg, J H F; Farge-Bancel, D; Gennery, A; Kröger, N; Lanza, F; Marsh, J C; Nagler, A; Peters, C; Velardi, A; Mohty, M; Madrigal, A

    2015-08-01

    This is the sixth special report that the European Society for Blood and Marrow Transplantation regularly publishes on the current practice and indications for haematopoietic SCT for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred in the field of haematopoietic SCT over the last years. Cord blood units as well as haploidentical donors have been increasingly used as stem cell sources for allo-SCT, thus, augmenting the possibility of finding a suitable donor for a patient. Continuous refinement of conditioning strategies has also expanded not only the number of potential indications but also has permitted consideration of older patients or those with co-morbidity for a transplant. There is accumulating evidence of the role of haematopoietic SCT in non-haematological disorders such as autoimmune diseases. On the other hand, the advent of new drugs and very effective targeted therapy has challenged the role of SCT in some instances or at least, modified its position in the treatment armamentarium of a given patient. An updated report with revised tables and operating definitions is presented. PMID:25798672

  7. Research and development in haematology. A report on international congresses and visit to academic centres in Europe.

    PubMed

    Wood, L

    1990-01-01

    Haematology is one of the most rapidly expanding disciplines in medicine and nursing. As occurs in other highly specialised areas, optimum care is now largely of a multidisciplinary nature. In this context there are literally unlimited opportunities for the involvement of professional nurses and, as I have attempted to illustrate in this report, integration in all aspects of research and development and active participation in presentation of research data and discussion at international meetings is one direction in which fulfillment of academic aspirations can be achieved. It is my viewpoint, based on more than a decade of direct involvement in all the activities of our department in Cape Town that these are entirely attainable goals. There is currently, in our country, a concerted move afoot to develop an improved career structure for the professional nurse along the lines of the American clinical nurse specialist. Much of this experience overseas would strongly support that commitment. It was my privilege to enjoy the confidence of the department, university and medical school sufficient for me to present research data at international meetings and to be a welcome visitor at some of the world's premier academic and research institutions. That this was possible reflects the uncompromising commitment in Haematology to the position of the professional nurse as an integral and equal part of the multidisciplinary health care team. PMID:1977529

  8. Molecular epidemiology of vancomycin-resistant Enterococcus faecium strains isolated from haematological malignancy patients in a research hospital in Turkey.

    PubMed

    Kirdar, S; Sener, A G; Arslan, U; Yurtsever, S G

    2010-06-01

    Infections and outbreaks of vancomycin-resistant enterococci (VRE) still appear to be rare in Turkey. In the present study, VRE strains isolated during an outbreak in a haematology unit of a training and research hospital in Turkey were typed and their antimicrobial-resistance patterns were characterized by molecular methods. Twelve vancomycin-resistant Enterococcus faecium strains isolated from patients with haematological malignancies were investigated by PCR for the presence of genes encoding resistance to vancomycin, tetracycline, chloramphenicol, gentamicin and erythromycin. Their clonal relationship was evaluated by PFGE and multilocus sequence typing. All strains were resistant to vancomycin and erythromycin, and had the vanA and ermB genes, respectively. PFGE was used to determine the presence of two pulsotypes and determine their subtypes. Pulsotype A belonged to sequence type (ST) 17 and pulsotype B belonged to ST 78. All strains with the vanA gene were not the same clone, indicating multiple acquisitions of resistant isolates, even over such a short time period. PMID:20223901

  9. Perceived need for information among patients with a haematological malignancy: associations with information satisfaction and treatment decision-making preferences.

    PubMed

    Rood, Janneke A J; van Zuuren, Florence J; Stam, Frank; van der Ploeg, Tjeerd; Eeltink, Corien; Verdonck-de Leeuw, Irma M; Huijgens, Peter C

    2015-06-01

    For patients with haematological malignancies, information on disease, prognosis, treatment and impact on quality of life is of the utmost importance. To gain insight into the perceived need for information in relation to sociodemographic and clinical parameters, comorbidity, quality of life (QoL) and information satisfaction, we compiled a questionnaire based on existing validated questionnaires. A total of 458 patients diagnosed with a haematological malignancy participated. The perceived need for information was moderate to high (40-70%). Multivariate regression analyses showed that a higher need for information was related to younger age, worse QoL, being member of a patient society and moderate comorbidity. The need for disease and treatment-related information was higher than the need for psychosocial information. A higher need for disease and treatment-related information was associated to being diagnosed with multiple myeloma. A higher need for psychosocial information was related to a lower educational level. The information provision could be improved according to 41% of the patients. Higher satisfaction with provided information was associated with better QoL. Most patients (62%) reported that they wanted to be fully informed about their illness and actively involved in treatment decision-making. The results contribute to improving patient-tailored information provision and shared decision-making in clinical practice. PMID:24811073

  10. Effects of probiotic supplementation over 5 months on routine haematology and clinical chemistry measures in healthy active adults.

    PubMed

    Cox, A J; West, N P; Horn, P L; Lehtinen, M J; Koerbin, G; Pyne, D B; Lahtinen, S J; Fricker, P A; Cripps, A W

    2014-11-01

    Use of probiotic-containing foods and probiotic supplements is increasing; however, few studies document safety and tolerability in conjunction with defined clinical end points. This paper reports the effects of 150 days of supplementation with either a single- (Bifidobacterium animalis subsp. lactis Bl-04) or a double-strain (Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07) probiotic on routine haematology and clinical chemistry measures in healthy active adults. Pre- to post-intervention changes in laboratory measures were determined and compared between supplement and placebo groups. Overall there were few differences in routine haematology and clinical chemistry measures between supplement and placebo groups post-intervention. Exceptions included plasma calcium (P=0.03) and urea (P=0.015); however, observed changes were small and within assay-specific laboratory reference ranges. These data provide evidence supporting the use of these probiotic supplements over a period of 5 months in healthy active adults without obvious safety or tolerability issues. PMID:25052229

  11. Clinical trial designs to obtain marketing authorization of drugs for haematological malignancy in Japan, the EU and the US.

    PubMed

    Nagai, Sumimasa; Ozawa, Keiya

    2016-07-01

    Differences in regulatory actions between Japan, the European Union (EU) and the United States (US) regarding the approval date and primary endpoints of pivotal trials have never been analysed comprehensively. This study aimed to examine such differences in haematological malignancy indications not only in applications for new molecular entity agents but also in supplemental applications for additional indications. A total of 101 haematological malignancy indications were examined for 58 drugs. Only 30 indications were approved by the regulatory agencies of all three regions with 25, 9 and 67 indications being first approved in Japan, the EU and the US, respectively. Regarding the 18 indications approved only in the US, 13 were approved based on results of single-arm trials. The approval of all nine indications approved first in the EU was based on results of comparative trials. The primary endpoints were different between the EU and the US in 4 of 49 indications approved by both regulatory agencies, all of which were approved earlier in the US than in the EU. This analysis shows that the US Food and Drug Administration has taken the most active attitude to acceptance of surrogate endpoints in single-arm trials. Therefore, not only shorter review time but also this attitude may lead to earlier approval in US. PMID:27018163

  12. Preliminary study of the fungal ecology at the haematology and medical-oncology ward in Bamako, Mali.

    PubMed

    Niaré-Doumbo, Safiatou; Normand, Anne Cécile; Diallo, Yacouba Lazarre; Dembelé, Abdoul Karim; Thera, Mahamadou A; Diallo, Dapa; Piarroux, Renaud; Doumbo, Ogobara; Ranque, Stéphane

    2014-08-01

    Data on fungal epidemiology in sub-Saharan African countries are scarce. This exploratory study aimed to characterize the fungal flora at the Onco-Haematology ward of the National Teaching Hospital of Point G in Bamako, Mali. A cross-sectional survey was conducted in the dry and in the rainy seasons. Nasal swab and sputum samples were collected from the hospitalized patients while airborne fungal spores were collected using electrostatic dust-fall collectors. Fungi were identified by their morphological characteristics and MALDI-TOF mass spectrometry. Candida albicans was the most frequent yeast species colonizing patients; Aspergillus species were isolated in 86 % of the patients and were the main airborne environmental contaminants. Overall, airborne fungal contamination rates increased from 33.8 % in the dry to 66.2 % in the rainy season (p < 0.001). The most frequent Aspergillus species were Aspergillus niger (36.6 %) and Aspergillus flavus (32.92 %). In contrast, Aspergillus fumigatus (5.43 %) was relatively rare. This high level of fungal exposure raises concern regarding the management of at-risk patients in this Onco-Haematology ward and stresses the need for strengthening the mycological diagnostic capacities to accompany the implementation of adapted fungal infection prevention and management policies. PMID:24889723

  13. Experiential relationship between malaria parasite density and some haematological parameters in malaria infected male subjects in Port Harcourt, Nigeria.

    PubMed

    M, Eze Evelyn; Ezeiruaku, F C; Ukaji, D C

    2012-07-01

    This study examined the experiential relationship between the parasite density and haematological parameters in male patients with Plasmodium falciparum infection in Port Harcourt, Nigeria reporting to malaria clinics. A total of one hundred and thirty-six (136) male patients were recruited. QBC haematological analysis, QBC malaria parasite specie identification and quantification and thin blood film for differential leucocytes count was used. The mean values of the haematological parameters in each quartile of parasite densities were determined using Microsoft Excel statistical package. Regression analysis was employed to model the experiential relationship between parasite density and haematological parameters. All regression relationships were tested and the relationship with the highest coefficient of determination (R2) was accepted as the valid relationship. The relationships tested included linear, polynomial, exponential, logarithmic and power relationships. The X- axis of the regression graphs stand for the parasite density while Y-axis stands for the respective haematological parameters  Neutrophil count had a negative  exponential relationship with the parasite density and is related to the parasite density by a polynomial equation model: ynm = -7E-07x2 - 0.0003x + 56.685.The coefficient of determination (R2) was 0.6140. This means that the rate of change of the parasitemia will depend on the initial value of the neutrophil. As the neutrophil increases, the parasitemia will tend to decrease in a double, triple and quadruple manner. The relationship between lymphocyte count, monocyte count and eosinophil count and parasite density was logarithmic and expressed by the following linear equation models: ylm = -2.371ln(x) + 37.296, ymm = 0.6965ln(x) + 5.7692 and yem = 0.9334ln(x) + 4.1718 in the same order. Their respective high coefficients of determination (R2) were 0.8027, 0.8867 and 0.9553. This logarithmic relationship means that each doubling of

  14. Assessment of haematological parameters in HIV-infected and uninfected Rwandan women: a cross-sectional study

    PubMed Central

    Munyazesa, Elisaphane; Emile, Ivan; Mutimura, Eugene; Hoover, Donald R; Shi, Qiuhu; McGinn, Aileen P; Musiime, Stephenson; Muhairwe, Fred; Rutagengwa, Alfred; Dusingize, Jean Claude; Anastos, Kathryn

    2012-01-01

    Objectives Although haematological abnormalities are common manifestations of HIV infection, few studies on haematological parameters in HIV-infected persons have been undertaken in sub-Saharan Africa. The authors assessed factors associated with haematological parameters in HIV-infected antiretroviral-naïve and HIV-uninfected Rwandan women. Study design Cross-sectional analysis of a longitudinal cohort. Setting Community-based women's associations. Participants 710 HIV-infected (HIV+) antiretroviral-naïve and 226 HIV-uninfected (HIV−) women from the Rwanda Women's Interassociation Study Assessment. Haematological parameters categorised as (abnormal vs normal) were compared by HIV status and among HIV+ women by CD4 count category using proportions. Multivariate logistic regression models using forward selection were fit. Results Prevalence of anaemia (haemoglobin (Hb) <12.0 g/dl) was higher in the HIV+ group (20.5% vs 6.3%; p<0.001), and increased with lower CD4 counts: ≥350 (7.6%), 200–349 (16%) and <200 cells/mm3 (32.2%). Marked anaemia (Hb <10.0 g/dl) was found in 4.2% of HIV+ and none of the HIV− women (p<0.001), and was highest in HIV+ women with CD4 <200 cells/mm3 (8.4%). The HIV+ were more likely than HIV− women (4.2 vs 0.5%, respectively, p=0.002) to have moderate neutropenia with white blood cells <2.0×103 cells/mm3 and 8.4% of HIV+ women with CD4 <200 cells/mm3 had moderate neutropenia. In multivariate logistic regression analysis, BMI (OR 0.87/kg/m2, 95% CI 0.82 to 0.93; p<0.001), CD4 200–350 vs HIV− (OR 3.59, 95% CI 1.89 to 6.83; p<0.001) and CD4 <200 cells/mm3 vs HIV− (OR 8.09, 95% CI 4.37 to 14.97; <0.001) had large independent associations with anaemia. There were large independent associations of CD4 <200 cells/mm3 vs HIV− (OR 7.18, 95% CI 0.78 to 65.82; p=0.081) and co-trimoxazole and/or dapsone use (OR 5.69, 95% CI 0.63 to 51.45; p=0.122) with moderate neutropenia. Conclusions Anaemia was more common than neutropenia or

  15. Nod Factor Effects on Root Hair-Specific Transcriptome of Medicago truncatula: Focus on Plasma Membrane Transport Systems and Reactive Oxygen Species Networks.

    PubMed

    Damiani, Isabelle; Drain, Alice; Guichard, Marjorie; Balzergue, Sandrine; Boscari, Alexandre; Boyer, Jean-Christophe; Brunaud, Véronique; Cottaz, Sylvain; Rancurel, Corinne; Da Rocha, Martine; Fizames, Cécile; Fort, Sébastien; Gaillard, Isabelle; Maillol, Vincent; Danchin, Etienne G J; Rouached, Hatem; Samain, Eric; Su, Yan-Hua; Thouin, Julien; Touraine, Bruno; Puppo, Alain; Frachisse, Jean-Marie; Pauly, Nicolas; Sentenac, Hervé

    2016-01-01

    Root hairs are involved in water and nutrient uptake, and thereby in plant autotrophy. In legumes, they also play a crucial role in establishment of rhizobial symbiosis. To obtain a holistic view of Medicago truncatula genes expressed in root hairs and of their regulation during the first hours of the engagement in rhizobial symbiotic interaction, a high throughput RNA sequencing on isolated root hairs from roots challenged or not with lipochitooligosaccharides Nod factors (NF) for 4 or 20 h was carried out. This provided a repertoire of genes displaying expression in root hairs, responding or not to NF, and specific or not to legumes. In analyzing the transcriptome dataset, special attention was paid to pumps, transporters, or channels active at the plasma membrane, to other proteins likely to play a role in nutrient ion uptake, NF electrical and calcium signaling, control of the redox status or the dynamic reprogramming of root hair transcriptome induced by NF treatment, and to the identification of papilionoid legume-specific genes expressed in root hairs. About 10% of the root hair expressed genes were significantly up- or down-regulated by NF treatment, suggesting their involvement in remodeling plant functions to allow establishment of the symbiotic relationship. For instance, NF-induced changes in expression of genes encoding plasma membrane transport systems or disease response proteins indicate that root hairs reduce their involvement in nutrient ion absorption and adapt their immune system in order to engage in the symbiotic interaction. It also appears that the redox status of root hair cells is tuned in response to NF perception. In addition, 1176 genes that could be considered as "papilionoid legume-specific" were identified in the M. truncatula root hair transcriptome, from which 141 were found to possess an ortholog in every of the six legume genomes that we considered, suggesting their involvement in essential functions specific to legumes. This

  16. Nod Factor Effects on Root Hair-Specific Transcriptome of Medicago truncatula: Focus on Plasma Membrane Transport Systems and Reactive Oxygen Species Networks

    PubMed Central

    Damiani, Isabelle; Drain, Alice; Guichard, Marjorie; Balzergue, Sandrine; Boscari, Alexandre; Boyer, Jean-Christophe; Brunaud, Véronique; Cottaz, Sylvain; Rancurel, Corinne; Da Rocha, Martine; Fizames, Cécile; Fort, Sébastien; Gaillard, Isabelle; Maillol, Vincent; Danchin, Etienne G. J.; Rouached, Hatem; Samain, Eric; Su, Yan-Hua; Thouin, Julien; Touraine, Bruno; Puppo, Alain; Frachisse, Jean-Marie; Pauly, Nicolas; Sentenac, Hervé

    2016-01-01

    Root hairs are involved in water and nutrient uptake, and thereby in plant autotrophy. In legumes, they also play a crucial role in establishment of rhizobial symbiosis. To obtain a holistic view of Medicago truncatula genes expressed in root hairs and of their regulation during the first hours of the engagement in rhizobial symbiotic interaction, a high throughput RNA sequencing on isolated root hairs from roots challenged or not with lipochitooligosaccharides Nod factors (NF) for 4 or 20 h was carried out. This provided a repertoire of genes displaying expression in root hairs, responding or not to NF, and specific or not to legumes. In analyzing the transcriptome dataset, special attention was paid to pumps, transporters, or channels active at the plasma membrane, to other proteins likely to play a role in nutrient ion uptake, NF electrical and calcium signaling, control of the redox status or the dynamic reprogramming of root hair transcriptome induced by NF treatment, and to the identification of papilionoid legume-specific genes expressed in root hairs. About 10% of the root hair expressed genes were significantly up- or down-regulated by NF treatment, suggesting their involvement in remodeling plant functions to allow establishment of the symbiotic relationship. For instance, NF-induced changes in expression of genes encoding plasma membrane transport systems or disease response proteins indicate that root hairs reduce their involvement in nutrient ion absorption and adapt their immune system in order to engage in the symbiotic interaction. It also appears that the redox status of root hair cells is tuned in response to NF perception. In addition, 1176 genes that could be considered as “papilionoid legume-specific” were identified in the M. truncatula root hair transcriptome, from which 141 were found to possess an ortholog in every of the six legume genomes that we considered, suggesting their involvement in essential functions specific to legumes. This

  17. Insight into the Nanoscale Mechanism of Rapid H2O Transport within a Graphene Oxide Membrane: Impact of Oxygen Functional Group Clustering.

    PubMed

    Ban, Shuai; Xie, Jing; Wang, Yajun; Jing, Bo; Liu, Bei; Zhou, Hongjun

    2016-01-13

    Realistic models of graphene oxide membranes were developed and validated to interpret the exceptional water permeation in association with X-ray photoelectron spectroscopy, thermogravimetric and differential scanning calorimetry analysis, and dynamic vapor sorption measurements. With respect to the GO oxidization level, surface distributions of functionalized domains were analyzed in line with TEM observations, and 3 types of interlayer domains in slit pores of GO membranes were identified. The hydrophilicity degrees of as-defined domains strongly influence their H2O uptake capacities. Calculated sorption enthalpies and isotherms are in good agreement with experimental data, and the results indicate the dominant role of dipole interactions. GO expansion shows a transition from the interstratification of an H2O monolayer to the accumulation of H2O multilayers at an interlayer distance of 0.8 nm. The evolution of both hydrogen bonds and H2O diffusivities suggests the existence of three types of H2O species with different binding states and molecular mobilities. The computed H2O permeability on the basis of sorption-diffusion theory supports the exceptional H2O transport capacity in GO membranes. PMID:26653332

  18. Crystallographic Studies of Xe And Kr Binding Within the Large Internal Cavity of Cytochrome Ba(3) From Thermus Thermophilus: Structural Analysis And Role of Oxygen Transport Channels in the Heme-Cu Oxidases

    SciTech Connect

    Luna, V.M.; Chen, Y.; Fee, J.A.; Stout, C.D.

    2009-05-26

    Cytochrome ba{sub 3} is a cytochrome c oxidase from the plasma membrane of Thermus thermophilus and is the preferred terminal enzyme of cellular respiration at low dioxygen tensions. Using cytochrome ba{sub 3} crystals pressurized at varying conditions under Xe or Kr gas, and X-ray data for six crystals, we identify the relative affinities of Xe and Kr atoms for as many as seven distinct binding sites. These sites track a continuous, Y-shaped channel, 18--20 {angstrom} in length, lined by hydrophobic residues, which leads from the surface of the protein where two entrance holes, representing the top of the Y, connect the bilayer to the {alpha}{sub 3}-Cu{sub B} center at the base of the Y. Considering the increased affinity of O{sub 2} for hydrophobic environments, the hydrophobic nature of the channel, its orientation within the bilayer, its connection to the active site, its uniform diameter, its virtually complete occupation by Xe, and its isomorphous presence in the native enzyme, we infer that the channel is a diffusion pathway for O{sub 2} into the dinuclear center of cytochrome ba{sub 3}. These observations provide a basis for analyzing similar channels in other oxidases of known structure, and these structures are discussed in terms of mechanisms of O{sub 2} transport in biological systems, details of CO binding to and egress from the dinuclear center, the bifurcation of the oxygen-in and water-out pathways, and the possible role of the oxygen channel in aerobic thermophily.

  19. Prolonged haematological toxicity from the hyper-CVAD regimen: manifestations, frequency, and natural history in a cohort of 125 consecutive patients.

    PubMed

    Gill, Saar; Lane, Steven W; Crawford, Julie; Cull, Gavin; Joske, David; Marlton, Paula; Mollee, Peter N; Prince, H Miles; Seymour, John F

    2008-09-01

    The hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone (hyper-CVAD) regimen has impressive efficacy in several haematological malignancies but is associated with considerable short-term haematological toxicity. Secondary myelodysplasia (MDS) or acute myeloid leukaemia (AML) also occurs. In this retrospective study, we also describe other prolonged haematological sequelae of this regimen. One hundred and twenty-five patients were treated with a median of six hyper-CVAD cycles and followed for a median of 28 months. Follow-up for cytopenias was censored at the next cytotoxic therapy. At 3 months post-therapy, 77 patients were evaluable. Cytopenias persisted in 59% of patients. Requirement for dose attenuation was the only factor significantly associated with persisting cytopenias (p<0.05). The median time to normalisation of counts for those with post-treatment cytopenias in the respective lineages was 9 months (range, 6-12) for anaemia, 6 months (range, 6-30) for neutropenia and 9 months (range, 6-30) for thrombocytopenia. MDS/AML was diagnosed in four patients at 4, 21, 24 and 37 months after therapy with a cumulative incidence rate of 4.43% at 4 years. These results indicate a considerable rate of prolonged haematological toxicity after hyper-CVAD and a modest rate of MDS at this limited follow-up. These findings likely reflect cumulative damage to haematopoietic stem cells. PMID:18401583

  20. Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for preventing bleeding in patients with haematological disorders after chemotherapy or stem cell transplantation

    PubMed Central

    Estcourt, Lise J; Stanworth, Simon; Doree, Carolyn; Trivella, Marialena; Hopewell, Sally; Murphy, Michael F; Tinmouth, Alan

    2014-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether different platelet transfusion thresholds for administration of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect the efficacy and safety of prophylactic platelet transfusions in preventing bleeding in patients with haematological disorders after chemotherapy with or without stem cell transplantation. PMID:25722651

  1. A lunar transportation system

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Due to large amounts of oxygen required for space travel, a method of mining, transporting, and storing this oxygen in space would facilitate further space exploration. The following project deals specifically with the methods for transporting liquid oxygen from the lunar surface to the Lunar Orbit (LO) space station, and then to the Lower Earth Orbit (LEO) space station. Two vehicles were designed for operation between the LEO and LO space stations. The first of these vehicles is an aerobraked design vehicle. The Aerobrake Orbital Transfer Vehicle (OTV) is capable of transporting 5000 lbm of payload to LO while returning to LEO with 60,000 lbm of liquid oxygen, and thus meet mission requirements. The second vehicle can deliver 18,000 lbm of payload to LO and is capable of bringing 60,000 lbm of liquid oxygen back to LEO. A lunar landing vehicle was also designed for operation between LO and the established moon base. The use of an electromagnetic railgun as a method for launching the lunar lander was also investigated. The feasibility of the railgun is doubtful at this time. A system of spheres was also designed for proper storing and transporting of the liquid oxygen. The system assumes a safe means for transferring the liquid oxygen from tank to tank is operational. A sophisticated life support system was developed for both the OTV and the lunar lander. This system focuses on such factors as the vehicle environment, waste management, water requirements, food requirements, and oxygen requirements.

  2. Haematological characteristics predicting susceptibility for ascites. 1. High carbon dioxide tensions in juvenile chickens.

    PubMed

    Scheele, C W; van Der Klis, J D; Kwakernaak, C; Buys, N; Decuypere, E

    2003-07-01

    1. Male broilers of two different genetic stocks, a pure broiler sire line (A) and commercially available Ross broilers (B), were used to study the effect of haematological characteristics in juvenile chickens on the development of clinical ascitic signs. Production performance (body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR)) from 448 birds per stock was measured from 2 to 5 weeks of age. Mortality was recorded from 2 to 6 weeks of age. The birds were housed at a low ambient temperature to stimulate the incidence of ascites. 2. From each stock, 32 birds with the highest (high risk: HRc) and 32 birds with the lowest (low risk: LRc) carbon dioxide tensions (pCO2) in venous blood were selected at 11 d of age. These birds were marked for future blood sampling to determine changes in pCO2 with age to relate these values to ascites susceptibility. 3. At 2 weeks of age all birds (including HRc and LRc birds) were allotted to 32 floor pens (one HRc and one LRc in each pen) per stock. Venous blood samples were collected weekly from HRc and LRc birds for blood gas analysis and haematocrit, and at week 5 also for thyroid hormone (T3, T4) concentrations in plasma. At 5 weeks of age all HRc and LRc birds were examined post-mortem, relative heart, lung, and liver weights and arterial pressure index (API) values were recorded. 4. Birds from stock A showed a lower BWG and FCR and notably higher ascites mortality compared with stock B. An effect of pCO2 tensions at d 11 was found on the incidence of ascitic signs in selected birds of both stocks up to week 5. From the HRc groups 30% of the birds showed ascitic signs, whereas this was only 8% in the LRc group. LRc birds of stock B in particular showed constant low API values (20 +/- 3%) and none of these birds showed signs of ascites. 5. Our results suggest that the ascites problem in Ross birds can be eliminated by selection for low pCO2 tensions in venous blood. Stock effects on API, liver weight, lung

  3. Haematological and serum biochemical parameters of West African Dwarf goats fed dried cassava leaves-based concentrate diets.

    PubMed

    Oni, Adebayo Olusoji; Arigbede, Oluwasanmi Moses; Sowande, Olusiji Sunday; Anele, Uchenna Young; Oni, Oluwakemi Oluremilekun; Onwuka, Chryss Friday Ijeoma; Onifade, Olufemi Sunday; Yusuf, Kafayat Omowumi; Dele, Peter Aniwe; Aderinboye, Ronke Yemisi

    2012-03-01

    The study was conducted to investigate the effects of feeding different levels of dried cassava leaves at 0%, 20%, 40% and 60%, respectively, using guinea grass as basal feed, on the haematological and serum biochemical parameters of West African Dwarf (WAD) goats. The study lasted for 116 days during which haematological and serum biochemical parameters were monitored in 40 male goats before and after, using a completely randomized design. At the start of the experiment, packed cell volume (PCV) ranged from 21.5% to 25.5% while haemoglobin concentration (Hb) and RBC significantly (P < 0.01) ranged from 7.3 to 8.6 g/dl and 10.4 to 13.2 × 10(12)/l, respectively. White blood cells reduced significantly (P < 0.05)) from 16.4 to 11.7 × 10(9)/l) as dried cassava leaves increased in the diets. At the end of the trial, there was a slight increase in the values of PCV and Hb in the diets (P > 0.05). Lymphocyte reduced significantly (P < 0.05) from 50.0% to 63.5% in the diets. Neutrophils, however, increased (P > 0.05) at the 0% to 40% levels and reduced at the 60% level of dried cassava leaves inclusion. At the start of the experiment, values for glucose significantly (P < 0.05) ranged from 40.1 to 56.0 mg/dl. Total protein and albumin values ranged significantly (P < 0.05) from 56.0 to 68.5 g/dl and 30.6 to 38.4 g/dl, respectively. At the end of the experiment, serum creatinine increased significantly (P < 0.05) as the level of dried cassava leaves increased from 0% to 60% in the diets. The study revealed that inclusion of dried cassava leaves in the diets of West African Dwarf goats had no deleterious effects on the haematological and serum biochemical parameters of WAD goats and could therefore be included in ruminant diets up to 60%. PMID:21744028

  4. Monitoring oxygenation.

    PubMed

    Severinghaus, John W

    2011-06-01

    Cyanosis was used for a century after dentists began pulling teeth under 100% N(2)O in 1844 because brief (2 min) severe hypoxia is harmless. Deaths came with curare and potent anesthetic respiratory arrest. Leland Clark's invention of a polarographic blood oxygen tension electrode (1954) was introduced for transcutaneous PO2 monitoring to adjust PEEP and CPAP PO2 to prevent premature infant blindness from excess O2 (1972). Oximetry for warning military aviators was tried after WW II but not used for routine monitoring until Takuo Aoyagi (1973) discovered an equation to measure SaO2 by the ratio of ratios of red and IR light transmitted through tissue as it changed with arterial pulses. Pulse oximetry (1982) depended on simultaneous technology improvements of light emitting red and IR diodes, tiny cheap solid state sensors and micro-chip computers. Continuous monitoring of airway anesthetic concentration and oxygen also became very common after 1980. Death from anesthesia fell 10 fold between 1985 and 2000 as pulse oximetry became universally used, but no proof of a causative relationship to pulse oximetry exists. It is now assumed that all anesthesiologist became much more aware of the dangers of prolonged hypoxia, perhaps by using the pulse oximeters. PMID:21717228

  5. The effects of short term dietary restriction on haematological responses and leukocyte gene expression of anovulatory and ovulatory beef heifers.

    PubMed

    Matthews, Daragh; Waters, Sinéad M; Diskin, Michael G; Kenny, David A; Morris, Dermot G; Earley, Bernadette

    2015-02-01

    The study objective was to characterise the impact of negative energy balance (NEB) on immune-stress responsiveness in beef heifers. A short term (18-day) dietary restriction model was used. Dietary restriction (0.4 maintenance (Mn) energy requirements) induced abrupt onset of anoestrus in nine heifers (Restricted Anovulatory; RA) while nineteen heifers maintained oestrous cyclicity (Restricted Ovulatory; RO). In addition a control (C) group of 12 heifers received a higher level of feeding (1.2 Mn). Haematological related biomarkers of husbandry stress, leukocyte gene expression of seven cytokine genes and five immunological biomarkers were investigated. After 18 days of differential feeding of the heifers alterations in eosinophil and monocyte numbers and altered expression of CXCL8, IL2 and TNFα could be attributed to diet restriction. More specifically, changes in these five variables were found in heifers that became anovulatory (RA) and are therefore considered to be more sensitive biomarkers to an energy deficit. PMID:25496833

  6. Evaluation of the platelet counting by Abbott CELL-DYN SAPPHIRE haematology analyser compared with flow cytometry.

    PubMed

    Grimaldi, E; Del Vecchio, L; Scopacasa, F; Lo Pardo, C; Capone, F; Pariante, S; Scalia, G; De Caterina, M

    2009-04-01

    The Abbot Cell-Dyn Sapphire is a new generation haematology analyser. The system uses optical/fluorescence flow cytometry in combination with electronic impedance to produce a full blood count. Optical and impedance are the default methods for platelet counting while automated CD61-immunoplatelet analysis can be run as selectable test. The aim of this study was to determine the platelet count performance of the three counting methods available on the instrument and to compare the results with those provided by Becton Dickinson FACSCalibur flow cytometer used as reference method. A lipid interference experiment was also performed. Linearity, carryover and precision were good, and satisfactory agreement with reference method was found for the impedance, optical and CD61-immunoplatelet analysis, although this latter provided the closest results in comparison with flow cytometry. In the lipid interference experiment, a moderate inaccuracy of optical and immunoplatelet counts was observed starting from a very high lipid value. PMID:18177435

  7. Brand of dipotassium EDTA vacuum tube as a new source of pre-analytical variability in routine haematology testing.

    PubMed

    Lima-Oliveira, G; Lippi, G; Salvagno, G L; Montagnana, M; Poli, G; Solero, G P; Picheth, G; Guidi, G C

    2013-01-01

    This study assesses the use of different dry K2 (dipotassium) EDTA vacuum tubes and whether or not they might represent a bias in haematological testing. Blood was collected in three dipotassium EDTA vacuum tubes from different manufacturers: Venosafe, Vacuette and Vacutainer. Samples were analysed on an Advia 2120i analyser. Significant differences among results and biases were compared with current quality specifications. Significant differences were found for haematocrit (HCT), mean corpuscular volume (MCV), white blood cell count (WBC) and platelet distribution width (PDW) when comparing Venosafe vs. Vacuette; for MCV, WBC and PDW when comparing Venosafe vs. Vacutainer; and for HCT and MCV when comparing Vacuette vs. Vacutainer. Clinically significant variations were observed for HCT and PDW in Venosafe vs. Vacuette; PDW in Venosafe vs. Vacutainer; and HCT and MCV in Vacuette vs. Vacutainer. The use of dipotassium EDTA vacuum tubes from different manufacturers represent a clinically relevant source of variation for HCT, MCV and PDW. PMID:23617091

  8. The concentrations of methaemoglogin, carboxyhaemoglobin and some haematological parameters in tobacco snuff addicts in Igbo of Nigeria.

    PubMed

    Ureme, S O; Ibeagha, I D; Maduka, I G; Ibeagbulam, O G

    2007-01-01

    Methaemoglobin, carboxyhaemoglobin concentrations and some haematological parameters were studied in fifty tobacco snuff addicts (40 males and 10 females) in some villages of Anambra State, Nigeria. The aim was to investigate possible adverse effects of tobacco snuff in addicts in Igbos of Anambra State. Fifty apparently healthy persons (25 males and 25 females) who do not inhale snuff were used as controls. The age range of tests and control subjects was 25-65 years. The results showed no statistically significant difference when the tests group was compared with the control group. A comparison of the results on the basis of sex, age and period of exposure, showed no significant differences. Blood picture in test and control groups was normocytic and normochromic. The results suggest that tobacco snuff may not have any adverse effect on haemoglobin metabolism and erythropoiesis. PMID:18379614

  9. Parameters of haematology, clinical chemistry and lipid metabolism in the common marmoset and alterations under stress conditions.

    PubMed

    Kuehnel, F; Grohmann, J; Buchwald, U; Koeller, G; Teupser, D; Einspanier, A

    2012-08-01

    Common marmosets are suitable non-human primate models for many human diseases. Standard values for blood parameters are required to evaluate physiological and pathological situations. Two studies were conducted: study I to determine standard values and study II to examine these under changed housing conditions. In study I, all parameters for clinical chemistry were similar in range for both genders with these specifics: male marmosets had significantly higher total and LDL cholesterol levels than females, whereas the mean corpuscular volume and the mean corpuscular haemoglobin were significantly lower than in females. In study II, glucose, lymphocytes and salivary cortisol were significantly lower, and faecal cortisol was increased during the change of housing conditions. In conclusion, standard values for haematology and clinical chemistry for the common marmoset were determined. Further on, parameters that are influenced by relocation stress and its importance for experimental results are described. PMID:22765494

  10. Haematological and biochemical measurements in healthy, adult, free-ranging golden jackals (Canis aureus syriacus) held in captivity.

    PubMed

    Aroch, I; Shpigel, N Y; Avidar, Y; Yakobson, B; King, R; Shamir, M

    2005-09-10

    Blood from 31 healthy, free-ranging golden jackals held in captivity for seven days was collected while they were anaesthetised. Haematological and serum biochemical measurements were analysed and the 95 per cent confidence interval for each variable was compared with the reference value for domestic dogs. The measurements of their red blood cells were within the reference interval for dogs, but the jackals had higher white blood cell counts and eosinophil counts than dogs. The male jackals had a higher haematocrit, red blood cell count, mean corpuscular volume and mean corpuscular haemoglobin concentration, and a lower red blood cell distribution width than the female jackals. High activities of muscle enzymes were detected in many of the jackals, in several of which the activity of creatine kinase exceeded 5000 U/l; these were considered abnormal. PMID:16155240

  11. The protective effect of hydrated sodium calcium aluminosilicate against haematological, biochemical and pathological changes induced by Zearalenone in mice.

    PubMed

    Abbès, Samir; Ouanes, Zouhour; ben Salah-Abbès, Jalila; Houas, Zohra; Oueslati, Ridha; Bacha, Hassen; Othman, Omar

    2006-04-01

    Hydrated sodium calcium aluminosilicate (HSCAS), an anticaking agent for mixed feed, was added alone or simultaneously with a toxic Zearalenone (ZEN) dose to balb/c mice and was evaluated for its ability to restore damages induced by ZEN. The latter is a mycotoxin produced by fusarium genera; it is mainly known to induce several toxic effects such as hepatotoxicity, immunotoxicity and nephrotoxicity on animals and humans. The experimental approach consisted of eight treatments of six mice each by 400 mg/kg bw or 5 g/kg bw of HSCAS. Two experimental groups have received respectively ZEN alone at 40 (8% of LD50) and at 500 mg/kg bw (LD50). Two other groups have received ZEN at 40 or 500 mg/kg bw combined respectively with HSCAS at 400 mg/kg bw and 5 g/kg bw. The control groups received water or olive oil. Forty-eight hours after treatment, blood samples were collected for haematological and serum biochemical parameters measurements. ZEN treatment significantly increased hematocrit, haemoglobin, white blood cells: lymphocytes, eosinophils, neutrophils, monocytes and the most of biochemical serum parameters; it significantly reduced platelets and induced degenerative changes in the hepatic and renal tissues; while, the mixture of HSCAS with ZEN induced a reestablishment of haematological parameters, levels of serum biochemical enzyme activities and histological pictures of both liver and kidney. It also prevented general toxicity of ZEN. This was observed by the shift of LD50 for this toxin. Thus, our data strongly suggested that deleterious effects of ZEN could be overcome or, at least, significantly were diminished by HSCAS. Moreover, this sorbent by itself did not show any toxic effects. PMID:16563452

  12. Blood haematology, serum thyroid hormones and glutathione peroxidase status in kacang goats fed inorganic iodine and selenium supplemented diets.

    PubMed

    Aghwan, Z A; Sazili, A Q; Alimon, A R; Goh, Y M; Hilmi, M

    2013-11-01

    The effects of dietary supplementation of selenium (Se), iodine (I), and a combination of both on the blood haematology, serum free thyroxine (FT4) and free triiodothyronine (FT3) hormones and glutathione peroxidase enzyme (GSH-Px) activity were examined on twenty four (7 to 8 months old, 22±1.17 kg live weight) Kacang crossbred male goats. Animals were randomly assigned to four dietary treatments (6 animals in each group). Throughout 100 d of feeding trial, the animals of control group (CON) received a basal diet, while the other three groups were offered basal diet supplemented with 0.6 mg/kg diet DM Se (SS), or 0.6 mg/kg diet DM I (PI), or a combination of both Se and I, each at 0.6 mg/kg diet DM (SSPI). The haematological attributes which are haemoglobin (Hb), red blood cell (RBC), packed cell volume (PCV), mean cell volume (MCV), white blood cells (WBC), band neutrophils (B Neut), segmented neutrophils (S Neut), lymphocytes (Lymph), monocytes (Mono), eosinophils (Eosin) and basophils (Baso) were similar among the four treatment groups, while serum levels of Se and I increased significantly (p<0.05) in the supplemented groups. The combined dietary supplementation of Se and I (SSPI) significantly increased serum FT3 in the supplemented animals. Serum GSH-Px activity increased significantly in the animals of SS and SSPI groups. It is concluded that the dietary supplementation of inorganic Se and I at a level of 0.6 mg/kg DM increased serum Se and I concentration, FT3 hormone and GSH-Px activity of Kacang crossbred male goats. PMID:25049744

  13. Effectiveness of increasing the frequency of posaconazole syrup administration to achieve optimal plasma concentrations in patients with haematological malignancy.

    PubMed

    Park, Wan Beom; Cho, Joo-Youn; Park, Sang-In; Kim, Eun Jung; Yoon, Seonghae; Yoon, Seo Hyun; Lee, Jeong-Ok; Koh, Youngil; Song, Kyoung-Ho; Choe, Pyoeng Gyun; Yu, Kyung-Sang; Kim, Eu Suk; Bang, Su Mi; Kim, Nam Joong; Kim, Inho; Oh, Myoung-Don; Kim, Hong Bin; Song, Sang Hoon

    2016-07-01

    Few data are available on whether adjusting the dose of posaconazole syrup is effective in patients receiving anti-cancer chemotherapy. The aim of this prospective study was to analyse the impact of increasing the frequency of posaconazole administration on optimal plasma concentrations in adult patients with haematological malignancy. A total of 133 adult patients receiving chemotherapy for acute myeloid leukaemia or myelodysplastic syndrome who received posaconazole syrup 200 mg three times daily for fungal prophylaxis were enrolled in this study. Drug trough levels were measured by liquid chromatography-tandem mass spectrometry. In 20.2% of patients (23/114) the steady-state concentration of posaconazole was suboptimal (<500 ng/mL) on Day 8. In these patients, the frequency of posaconazole administration was increased to 200 mg four times daily. On Day 15, the median posaconazole concentration was significantly increased from 368 ng/mL [interquartile range (IQR), 247-403 ng/mL] to 548 ng/mL (IQR, 424-887 ng/mL) (P = 0.0003). The median increase in posaconazole concentration was 251 ng/mL (IQR, 93-517 ng/mL). Among the patients with initially suboptimal levels, 79% achieved the optimal level unless the steady-state level was <200 ng/mL. This study shows that increasing the administration frequency of posaconazole syrup is effective for achieving optimal levels in patients with haematological malignancy undergoing chemotherapy. PMID:27234674

  14. Blood Haematology, Serum Thyroid Hormones and Glutathione Peroxidase Status in Kacang Goats Fed Inorganic Iodine and Selenium Supplemented Diets

    PubMed Central

    Aghwan, Z. A.; Sazili, A. Q.; Alimon, A. R.; Goh, Y. M.; Hilmi, M.

    2013-01-01

    The effects of dietary supplementation of selenium (Se), iodine (I), and a combination of both on the blood haematology, serum free thyroxine (FT4) and free triiodothyronine (FT3) hormones and glutathione peroxidase enzyme (GSH-Px) activity were examined on twenty four (7 to 8 months old, 22±1.17 kg live weight) Kacang crossbred male goats. Animals were randomly assigned to four dietary treatments (6 animals in each group). Throughout 100 d of feeding trial, the animals of control group (CON) received a basal diet, while the other three groups were offered basal diet supplemented with 0.6 mg/kg diet DM Se (SS), or 0.6 mg/kg diet DM I (PI), or a combination of both Se and I, each at 0.6 mg/kg diet DM (SSPI). The haematological attributes which are haemoglobin (Hb), red blood cell (RBC), packed cell volume (PCV), mean cell volume (MCV), white blood cells (WBC), band neutrophils (B Neut), segmented neutrophils (S Neut), lymphocytes (Lymph), monocytes (Mono), eosinophils (Eosin) and basophils (Baso) were similar among the four treatment groups, while serum levels of Se and I increased significantly (p<0.05) in the supplemented groups. The combined dietary supplementation of Se and I (SSPI) significantly increased serum FT3 in the supplemented animals. Serum GSH-Px activity increased significantly in the animals of SS and SSPI groups. It is concluded that the dietary supplementation of inorganic Se and I at a level of 0.6 mg/kg DM increased serum Se and I concentration, FT3 hormone and GSH-Px activity of Kacang crossbred male goats. PMID:25049744

  15. Modeling [15O] oxygen tracer data for estimating oxygen consumption

    PubMed Central

    Deussen, Andreas; Bassingthwaighte, James B.

    2010-01-01

    The most direct measure of oxidative tissue metabolism is the conversion rate of oxygen to water via mitochondrial respiration. To calculate oxygen consumption from the analysis of tissue residue curves or outflow dilution curves after injection of labeled oxygen one needs realistic mathematical models that account for convection, diffusion, and transformation in the tissue. A linear, three-region, axially distributed model accounts for intravascular convection, penetration of capillary and parenchymal cell barriers (with the use of appropriate binding spaces to account for oxygen binding to hemoglobin and myoglobin), the metabolism to [15O]water in parenchymal cells, and [15O]water transport into the venous effluent. Model solutions fit residue and outflow dilution data obtained in an isolated, red blood cell-perfused rabbit heart preparation and give estimates of the rate of oxygen consumption similar to those obtained experimentally from the flow times the arteriovenous differences in oxygen contents. The proposed application is for the assessment of regional oxidative metabolism in vivo from tissue 15O-residue curves obtained by positron emission tomography. PMID:8780210

  16. Oxygen Releasing Biomaterials for Tissue Engineering

    PubMed Central

    Camci-Unal, Gulden; Alemdar, Neslihan; Annabi, Nasim; Khademhosseini, Ali

    2013-01-01

    Due to the increasing demand to generate thick and vascularized tissue engineered constructs, novel strategies are currently being developed. An emerging example is the generation of oxygen-releasing biomaterials to tackle mass transport and diffusion limitations within engineered tissue-like constructs. Biomaterials containing oxygen releasing molecules can be fabricated in various forms such as, hybrid thin films, microparticles, or three dimensional (3D) scaffolds. In this perspective, we will summarize various oxygen-releasing reagents and their potential applications in regenerative engineering. Moreover, we will review the main approaches to fabricate oxygen-releasing biomaterials for a range of tissue engineering applications. PMID:23853426

  17. Oxygen tensioactivity on liquid-metal drops.

    PubMed

    Ricci, E; Arato, E; Passerone, A; Costa, P

    2005-12-14

    The influence of oxygen on the surface tension of liquid metals is a topic of undoubted interest as the formation of oxide films, or even oxygen contamination of the metal interface, represents the main source of error in determining the surface tension. The evaluation of gas-atmosphere mass exchanges under stationary conditions allows the evaluation of an effective oxygen pressure at which the oxidation of metal becomes evident. This effective oxygen pressure can be considered as a property of the system and, according to experimental evidence, can be many orders of magnitude greater than the equilibrium pressure. The measurement of the surface tension is a good way of studying interface properties, their temporal change and their connections to transport and reaction rates. This paper represents a review of a work undertaken with the aim of understanding oxygen mass transport at the liquid metal surface in relation to the study of capillary phenomena at high temperature. PMID:16098947

  18. 14 CFR 25.1450 - Chemical oxygen generators.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... device which produces oxygen by chemical reaction. (b) Each chemical oxygen generator must be designed... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Chemical oxygen generators. 25.1450 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1450...

  19. 14 CFR 25.1450 - Chemical oxygen generators.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... device which produces oxygen by chemical reaction. (b) Each chemical oxygen generator must be designed... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Chemical oxygen generators. 25.1450 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1450...

  20. 14 CFR 25.1450 - Chemical oxygen generators.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... device which produces oxygen by chemical reaction. (b) Each chemical oxygen generator must be designed... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Chemical oxygen generators. 25.1450 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1450...

  1. 14 CFR 25.1450 - Chemical oxygen generators.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... device which produces oxygen by chemical reaction. (b) Each chemical oxygen generator must be designed... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Chemical oxygen generators. 25.1450 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1450...

  2. 14 CFR 25.1450 - Chemical oxygen generators.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... device which produces oxygen by chemical reaction. (b) Each chemical oxygen generator must be designed... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Chemical oxygen generators. 25.1450 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1450...

  3. The nature of undergraduates' conceptual understanding of oxygen transport and utilization in humans: Can cardiopulmonary simulation software enhance learning of propositional knowledge and/or diagnose alternative conceptions in novices and intermediates?

    NASA Astrophysics Data System (ADS)

    Wissing, Dennis Robert

    The purpose of the this research was to explore undergraduates' conceptual development for oxygen transport and utilization, as a component of a cardiopulmonary physiology and advanced respiratory care course in the allied health program. This exploration focused on the student's development of knowledge and the presence of alternative conceptions, prior to, during, and after completing cardiopulmonary physiology and advanced respiratory care courses. Using the simulation program, SimBioSysTM (Samsel, 1994), student-participants completed a series of laboratory exercises focusing on cardiopulmonary disease states. This study examined data gathered from: (1) a novice group receiving the simulation program prior to instruction, (2) a novice group that experienced the simulation program following course completion in cardiopulmonary physiology, and (3) an intermediate group who experienced the simulation program following completion of formal education in Respiratory Care. This research was based on the theory of Human Constructivism as described by Mintzes, Wandersee, and Novak (1997). Data-gathering techniques were based on theories supported by Novak (1984), Wandersee (1997), and Chi (1997). Data were generated by exams, interviews, verbal analysis (Chi, 1997), and concept mapping. Results suggest that simulation may be an effective instructional method for assessing conceptual development and diagnosing alternative conceptions in undergraduates enrolled in a cardiopulmonary science program. Use of simulation in conjunction with clinical interview and concept mapping may assist in verifying gaps in learning and conceptual knowledge. This study found only limited evidence to support the use of computer simulation prior to lecture to augment learning. However, it was demonstrated that students' prelecture experience with the computer simulation helped the instructor assess what the learner knew so he or she could be taught accordingly. In addition, use of computer

  4. Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy, 2014.

    PubMed

    Chau, M M; Kong, D C M; van Hal, S J; Urbancic, K; Trubiano, J A; Cassumbhoy, M; Wilkes, J; Cooper, C M; Roberts, J A; Marriott, D J E; Worth, L J

    2014-12-01

    Antifungal agents may be associated with significant toxicity or drug interactions leading to sub-therapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy. These risks may be minimised by clinical assessment, laboratory monitoring, avoidance of particular drug combinations and dose modification. Specific measures, such as the optimal timing of oral drug administration in relation to meals, use of pre-hydration and electrolyte supplementation may also be required. Therapeutic drug monitoring (TDM) of antifungal agents is warranted, especially where non-compliance, non-linear pharmacokinetics, inadequate absorption, a narrow therapeutic window, suspected drug interaction or unexpected toxicity are encountered. Recommended indications for voriconazole and posaconazole TDM in the clinical management of haematology patients are provided. With emerging knowledge regarding the impact of pharmacogenomics upon metabolism of azole agents (particularly voriconazole), potential applications of pharmacogenomic evaluation to clinical practice are proposed. PMID:25482746

  5. The effect of fasting during Ramadan on parameters of the haematological and steroidal modules of the athletes biological passport - a pilot study.

    PubMed

    Alsaadi, K; Voss, S C; Kraiem, S; Alwahaibi, A; Alyazedi, S; Dbes, N; Goebel, R; Mohamed-Ali, V; Alsowaidi, S; Seyam, A M; Bashraheel, A S; Alsayrafi, M; Georgakopoulos, C

    2015-01-01

    This study investigated the effect of Ramadan on the haematological and steroid module of the Athletes Biological Passport (ABP) of the World Anti-Doping Agency (WADA). Nine healthy physically active subjects were tested in the morning and afternoon for two days before and three days during Ramadan. Sample collection and all analyses were performed according to WADA technical documents. Although there were significant changes in the haemoglobin concentration during Ramadan, especially during the first fasting week, none of the subjects in this study exceeded the individually calculated thresholds of the ABP. No significant effects on testosterone/epitestosterone (T/E) ratio were observed but only the afternoon specific gravity (SG) of the urine was elevated. Thus, when urinary steroid concentrations are required, SG corrections need to be performed. The haematological and the steroid module of the ABP can be reliably applied during Ramadan as the observed changes are only marginal. PMID:26695489

  6. Effect of high wavelengths low intensity light during dark period on physical exercise performance, biochemical and haematological parameters of swimming rats.

    PubMed

    Beck, W; Gobatto, C

    2016-03-01

    Nocturnal rodents should be assessed at an appropriate time of day, which leads to a challenge in identifying an adequate environmental light which allows animal visualisation without perturbing physiological homeostasis. Thus, we analysed the influence of high wavelength and low intensity light during dark period on physical exercise and biochemical and haematological parameters of nocturnal rats. We submitted 80 animals to an exhaustive exercise at individualised intensity under two different illuminations during dark period. Red light (> 600 nm; < 15lux) was applied constantly during dark period (EI; for experimental illumination groups) or only for handling and assessments (SI; for standard illumination groups). EI led to worse haematological and biochemical conditions, demonstrating that EI alone can influence physiological parameters and jeopardise result interpretation. SI promotes normal physiological conditions and greater aerobic tolerance than EI, showing the importance of a correct illumination pattern for all researchers that employ nocturnal rats for health/disease or sports performance experiments. PMID:27030633

  7. Living with Oxygen Therapy

    MedlinePlus

    ... page from the NHLBI on Twitter. Living With Oxygen Therapy Oxygen therapy helps many people function better and be ... chronic obstructive pulmonary disease) Although you may need oxygen therapy continuously or for long periods, it doesn' ...

  8. Hyperbaric oxygen therapy

    MedlinePlus

    Hyperbaric oxygen therapy uses a special pressure chamber to increase the amount of oxygen in the blood. ... outpatient centers. The air pressure inside a hyperbaric oxygen chamber is about two and a half times ...

  9. Induction of ovarian function by using short-term human menopausal gonadotrophin in patients with ovarian failure following cytotoxic chemotherapy for haematological malignancy.

    PubMed

    Chatterjee, R; Mills, W; Katz, M; McGarrigle, H H; Goldstone, A H

    1993-07-01

    Currently no treatment has proved successful in inducing ovarian steroidogenic and/or gametogenic recovery in patients with haematological malignancies treated by cytotoxic chemotherapy once biochemical failure becomes manifest i.e., when FSH levels exceed 40 IU/L. This paper reports two such cases with classical biochemical ovarian failure in which ovarian function was induced by brief stimulation with Human Menopausal Gonadotrophin (HMG). PMID:7693105

  10. A therapeutic-only versus prophylactic platelet transfusion strategy for preventing bleeding in patients with haematological disorders after chemotherapy or stem cell transplantation

    PubMed Central

    Estcourt, Lise J; Crighton, Gemma L; Wood, Erica M; Stanworth, Simon; Trivella, Marialena; Doree, Carolyn; Tinmouth, Alan; Murphy, Michael F

    2014-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To determine whether a therapeutic-only platelet transfusion policy (platelet transfusions given when patient bleeds) is as effective and safe as a prophylactic platelet transfusion policy (platelet transfusions given to prevent bleeding usually when the platelet count falls below a given trigger level) in patients with haematological disorders undergoing myelosuppressive chemotherapy or stem cell transplantation. PMID:25722649

  11. Effects of age and season on haematological parameters of donkeys during the rainy and cold-dry seasons

    NASA Astrophysics Data System (ADS)

    Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

    2015-12-01

    The aim of the study was to investigate the effects of age and season on haematological parameters of donkeys at rest during the rainy and cold-dry seasons. Thirty healthy donkeys divided into three groups based on their age served as the subjects. During each season, blood sample was collected from each donkey thrice, 2 weeks apart, for haematological analysis, and the dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) were obtained thrice each day during the experimental period using standard procedures. During the rainy season, the mean DBT (33.05 ± 0.49 °C), RH (73.63 ± 1.09 %) and THI (84.39 ± 0.71) were higher ( P < 0.0001) than the corresponding values of 24.00 ± 0.44 °C, 36.80 ± 0.92 % and 64.80 ± 0.62, during the cold-dry season. Packed cell volume (PCV), erythrocyte count [red blood cell (RBC)], haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), platelet count (PLT), leucocyte count [white blood cell (WBC)], lymphocyte count (LYM) and neutrophil/lymphocyte ratio (N/L) were higher ( P < 0.05) in adults than foals during the rainy season. The MCV, MCH, WBC, NEU, LYM and PLT of adult and yearling donkeys were higher ( P < 0.05) during the rainy than the cold-dry season. The PCV, RBC, Hb, MCV, MCH, and NEU of foals were higher in the rainy than the cold-dry season. The N/L of adult and foal donkeys were higher ( P < 0.05) in the rainy than in the cold-dry season. In conclusion, PCV, RBC, Hb and LYM were considerably higher in foals than yearlings or adults during the rainy season, while erythrocytic indices and platelet counts were higher in adults or yearlings than in foals in both seasons. Erythrocytic indices, PLT and N/L were higher in the rainy than the cold-dry season in adults, yearlings and foals.

  12. Age-associated and breed-associated variations in haematological and biochemical variables in young labrador retriever and miniature schnauzer dogs.

    PubMed

    Brenten, Thomas; Morris, Penelope J; Salt, Carina; Raila, Jens; Kohn, Barbara; Schweigert, Florian J; Zentek, Jürgen

    2016-01-01

    Breed, sex and age effects on haematological and biochemical variables were investigated in 24 labrador retriever and 25 miniature schnauzer dogs during the first year of life. Blood samples were taken regularly between weeks 8 and 52. White blood cell and red blood cell counts, haemoglobin concentration, haematocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, platelet count as well as total protein, albumin, calcium, phosphate, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, glutamate dehydrogenase, total cholesterol, triglycerides, creatine and urea were evaluated. For all haematological and biochemical parameters, there were significant effects of age on test results. Statistically significant effects for breed and the breed×age interaction on test results were observed for most of the parameters with the exception of haemoglobin. Variations in test results illustrate growth related alterations in body tissue and metabolism leading to dynamic and marked changes in haematological and biochemical parameters, which have to be considered for the interpretation of clinical data obtained from dogs in the first year of life. PMID:27252875

  13. Clinical experience of the use of voriconazole, caspofungin or the combination in primary and salvage therapy of invasive aspergillosis in haematological malignancies.

    PubMed

    Raad, Issam I; Zakhem, Aline El; Helou, Gilbert El; Jiang, Ying; Kontoyiannis, Dimitrios P; Hachem, Ray

    2015-03-01

    Invasive aspergillosis (IA) is a life-threatening infection in severely immunocompromised haematological malignancy patients. In this study, the efficacy and safety of caspofungin, voriconazole or the combination as primary and salvage therapy in patients with IA were compared. The study included 181 patients with haematological malignancies and IA who received primary or salvage therapy with caspofungin, voriconazole or the combination. In total, 138 patients who received treatment for ≥7 days were analysed; 86 underwent primary antifungal therapy (15 with caspofungin, 38 with voriconazole and 33 with both). Among the salvage therapy patients, 17 received caspofungin, 24 received voriconazole and 35 received both. In the primary therapy group, no difference in therapy response was found, but caspofungin was associated with higher IA mortality rates. A multivariate competing risk analysis of primary antifungal therapy revealed that voriconazole was independently associated with lower IA-associated mortality rates than caspofungin (hazard ratio=0.2, 95% confidence interval 0.06-0.96; P=0.04). In the salvage therapy group, the three treatment groups had similar responses and IA-associated mortality rates. The combination of voriconazole and caspofungin did not result in better outcomes compared with voriconazole alone, as primary or salvage therapy, in haematological malignancy patients. However, voriconazole was associated with a lower Aspergillus-associated mortality rate compared with caspofungin monotherapy. PMID:25455847

  14. The role of vitamin C as antioxidant in protection of biochemical and haematological stress induced by chlorpyrifos in freshwater fish Clarias batrachus.

    PubMed

    Narra, Madhusudan Reddy; Rajender, Kodimyala; Rudra Reddy, R; Rao, J Venkateswara; Begum, Ghousia

    2015-08-01

    The study was conducted to explore the modulatory effects of chlorpyrifos and protective role of vitamin C in tissues of Clarias batrachus. Treatments include E1 group (basal diet plus 1.65mgL(-1) CPF) and E2 group (basal diet+200mgkg body weight vitamin C and 1.65mgL(-1) CPF) along with a control group of fishes (fed on basal diet only). After 1, 7, 15, and 30d of treatment, fish tissues (brain, blood and liver) were used for the estimation of growth, biochemical and haematological parameters. The results of E1 group indicated significantly lower weight gain and survival rate. Brain AChE activity was inhibited. The RBC, Hb, respiratory burst activity, total protein and HSI were also reduced whereas WBC count, plasma glucose and haematocrit were elevated. In contrast, liver glycogen content, lactate dehydrogenase, alkaline and acid phosphatase activities were inhibited and malate dehydrogenase, aspartate, alanine amino transferase were enhanced. The E2 group of fish exhibited significant improvement in growth, survival, haematological indices, brain AChE, liver glycogen and oxidative enzyme activity. The findings support that dietary vitamin C supplementation might be helpful in abrogation of chlorpyrifos toxicity and improves growth, survival, biochemical and haematological conditions in fishes. PMID:25855010

  15. Hair Today; Scalped Tomorrow: Massive Subgaleal Haematoma Following Sudden Hair Pulling in an Adolescent in the Absence of Haematological Abnormality or Skull Fracture.

    PubMed

    Edmondson, Sarah-Jayne; Ramman, Saif; Hachach-Haram, Nadine; Bisarya, Kamal; Fu, Brian; Ong, Juling; Akhavani, Mo

    2016-07-01

    Subgaleal haematoma (SH) is a rare condition, most frequently observed in neonates as a complication of Ventouse-assisted delivery. There have been few patients reported beyond this period. Those that are present within the literature have typically resulted from significant blunt scalp trauma, with or without associated skull fracture. Those resulting secondary to relatively minor trauma, such as hair braiding or hair pulling, are rare but have been reported and are often associated with underlying haematological abnormalities or nonaccidental injury patients. Most patients resolve spontaneously and without complication. The authors report a rare patient of a delayed presentation of a massive SH in an adolescent following a seemingly innocuous episode of hair pulling whilst play-fighting, in the absence of any underlying haematological or anatomical abnormality. Due to the size of the SH and the appearance of large areas of calcification within the haematoma, early liaison with senior neuroradiologists and haematologists, to rule out underlying anatomical and haematological abnormalities, respectively, was essential to guide appropriate management. Our patient highlights the need for an awareness of the possible aetiologies of SH and the necessity of early active multidisciplinary team involvement in the management of such patients, which is critical to ensure optimum patient outcomes. PMID:27258718