Science.gov

Sample records for haematology oxygen transport

  1. Artificial oxygen transport protein

    DOEpatents

    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. Reversible Oxygenation of Oxygen Transport Proteins.

    ERIC Educational Resources Information Center

    Drain, C. M.; Corden, Barry B.

    1987-01-01

    Describes a lecture demonstration which illustrates changes in the visible spectra of oxygen transport proteins upon reversible oxygen binding. Provides a comparison of the physical characteristics of oxygen storage and transport proteins. Reviews essentials for preparation of the materials. (ML)

  3. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2002-07-01

    In the present quarter, oxygen transport perovskite ceramic membranes 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. Red blood cell transfusion and skeletal muscle tissue oxygenation in anaemic haematologic outpatients

    PubMed Central

    Gavric, Ana Ursula; Podbregar, Eva; Mozina, Hugon; Stefanovic, Sebastian

    2016-01-01

    Abstract Background Stored red blood cells (RBCs) accumulate biochemical and biophysical changes, known as storage lesion. The aim of this study was to re-challenge current data that anaemia in chronically anaemic haematology patients is not associated with low skeletal muscle tissue oxygen (StO2), and that RBC storage age does not influence the tissue response after ischaemic provocation, using near-infrared spectroscopy. Patients and methods Twenty-four chronic anaemic haematology patients were included. Thenar skeletal muscle StO2 was measured at rest (basal StO2), with vascular occlusion testing (upslope StO2, maximum StO2) before and after transfusion. Results Basal StO2 was low (53% ± 7%). Average RBC storage time was 10.5 ± 3.9 days. Effects of RBC transfusions were as follows: basal StO2 and upslope StO2 did not change significantly; maximum StO2 increased compared to baseline (64 ± 14% vs. 59 ± 10%, p = 0.049). Change of basal StO2, upslope StO2 and maximum StO2 was negatively related to age of RBCs. The decrease of maximum StO2 was predicted (sensitivity 70%, specificity 100%), after receiving RBCs ≥ 10days old. Discussion Resting skeletal muscle StO2 in chronic anaemic patients is low. RBC storage time affects skeletal muscle StO2 in the resting period and after ischaemic provocation. PMID:27904454

  5. 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.

  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; 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.

  12. 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

    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.

  13. 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.

  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

    2005-02-01

    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. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate 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. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

  15. Transport properties of oxygen

    NASA Technical Reports Server (NTRS)

    Roder, H. M.

    1983-01-01

    Tables of viscosity, thermal conductivity, and thermal diffusivity of oxygen as a function of temperature and pressure from the triple point to 320 K and at pressures to 100 MPa are presented. Auxiliary tables in engineering units are also given. Viscosity and thermal conductivity are calculated from published correlations. Density and specific heat at constant pressure, required to calculate thermal diffusivity, are obtained from an equation of state. The Prandtl number can be obtained quite easily from the values tabulated.

  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

    Lu, Zigui; Plonczak, Pawel J.; Lane, Jonathan A.

    2016-11-08

    A method is described 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. Preferred materials are (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.7Fe.sub.0.3O.sub.3-.delta. for the porous fuel oxidation layer, (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer, and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.3Fe.sub.0.7O.sub.3-.delta. for the porous surface exchange layer. Firing the said fuel activation and separation layers in nitrogen atmosphere unexpectedly allows the separation layer to sinter into a fully densified mass.

  18. Composite oxygen transport membrane

    DOEpatents

    Christie, Gervase Maxwell; Lane, Jonathan A.

    2016-11-15

    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.

  19. Composite oxygen transport membrane

    DOEpatents

    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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Catalyst containing oxygen transport membrane

    DOEpatents

    Lane, Jonathan A.; Wilson, Jamie R.; Christie, Gervase Maxwell; Petigny, Nathalie; Sarantopoulos, Christos

    2017-02-07

    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 microstructure exhibiting substantially uniform pore size distribution as a result of using PMMA pore forming materials or a bi-modal particle size distribution of the porous support layer materials. 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.

  6. 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.

  7. Effect of 12-hour road transportation on physiological, immunological and haematological parameters in bulls housed at different space allowances.

    PubMed

    Gupta, S; Earley, B; Crowe, M A

    2007-05-01

    The effects of transporting Holstein Friesian bulls (n=72; bodyweight 403+/-3.5 kg) for 12h by road were examined. Adrenal, haematological and immune responses, body temperature and performance were recorded. The animals had been previously housed for 96 days at three space allowances (1.2, 2.7 or 4.2m(2) per bull). The bulls were allocated to one of two treatments: T (transport for 12h; n=16 per space allowance) and C (control; n=8 per space allowance). Basal cortisol plasma concentrations and interferon (IFN)-gamma production from cultured lymphocytes did not show any statistically significant difference (P>0.05) following the housing period. Removing bulls from their home pens and walking them to the pre-loading crush facility, loading onto the transporter, and unloading following the 12h road journey, significantly (P<0.001) increased plasma cortisol concentration. The bulls housed at 4.2m(2) had greater (P<0.05) plasma cortisol concentrations than bulls housed at 1.2m(2) at loading, unloading, or on return to the crush holding facility; those housed at 1.2m(2) had greater (P<0.05) plasma cortisol concentrations than bulls housed at 2.7 and 4.2m(2) in their home pens after transport. There was an increased (P<0.05) plasma cortisol response in the T than in the C bulls following adrenocorticotrophic hormone administration. Transport significantly reduced (P<0.05) IFN-gamma production, lymphocyte % and body weight and significantly increased (P<0.05) neutrophils, eosinophils, packed cell volume, red blood cell numbers and haemoglobin. In conclusion, housing bulls for 96 days in a range of space allowances did not affect basal cortisol response or immune function parameters. Whereas transport increased plasma cortisol and reduced the immune response in the short-term, the changes were transient and within normal physiological ranges, suggesting that 12h road transport had no adverse effect on welfare status over the longer term. Furthermore, transport of bulls

  8. A new oxygen transport agent.

    PubMed

    Standl, Thomas

    2005-04-01

    Modern highly purified and chemically modified hemoglobin-based oxygen carriers (HBOC) are free of significant side effects on kidneys and coagulation, and they do not possess ABO antigens, allowing transfusion without knowledge of the respective blood group. Even at room air oxygen concentrations HBOC can compensate for intravascular volume deficits in hemorrhagic shock, including restoration of colloid osmotic pressure and organ perfusion, and deliver oxygen to organs and tissues during nearly complete blood exchange. In animal experiments and clinical trials all HBOC showed a vasoconstrictive side-effect which is mainly caused by nitric oxide scavenging, and to a lesser extent by reactive vasoconstriction because of precapillary oxygen off-loading. The study by Bjorkholm in this issue of the journal (see page 505) investigates the application of a moderate dose of the newly designed HBOC, MP4, in volunteers. MP4 has a high molecular size and a very low p50 resulting in a high oxygen affinity thus avoiding significant (pre)capillary oxygen off-loading. No significant rises in blood pressure or major laboratory abnormalities were seen after MP4 infusion. This new HBOC may be applicable in patients as a red blood substitute where vasoconstriction must be avoided. In addition, poststenotic tissue oxygenation might be a further indication. However, the number of treated volunteers and the infused dose of MP4 were both are very small. Therefore, one cannot draw conclusions on the safety, tolerability and efficacy of MP4 in terms of red cell replacement when large amounts of oxygen carriers are needed.

  9. Ceramic oxygen transport membrane array reactor and reforming method

    DOEpatents

    Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-11-08

    The invention relates to a commercially viable modular ceramic oxygen transport membrane reforming reactor configured using repeating assemblies of oxygen transport membrane tubes and catalytic reforming reactors.

  10. 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.

  11. VERTEX: manganese transport through oxygen minima

    NASA Astrophysics Data System (ADS)

    Martin, John H.; Knauer, George A.

    1984-01-01

    Manganese transport through a well-developed oxygen minimum was studied off central Mexico (18°N, 108°W) in October-November 1981 as part of the VERTEX (Vertical Transport and Exchange) research program. Refractory, leachable and dissolved Mn fractions associated with particulates caught in traps set at eight depths (120-1950 m) were analyzed. Particles entering the oxygen minimum had relatively large Mn loads; however, as the particulates sank further into the minimum, total Mn fluxes steadily decreased from 190 nmol m -2 day -1 at 120 m to 36 nmol m -2 day -1 at 400 m. Manganese fluxes then steadily increased in the remaining 800-1950 m, reaching rates of up to 230 nmol m -2 day -1 at 1950 m. Manganese concentrations were also measured in the water column. Dissolved Mn levels < 3.0 nmol kg -1 were consistently observed within the 150-600 m depth interval. In contrast, suspended particulate leachable Mn amounts were especially low at those depths, and never exceeded 0.04 nmol kg -1. The combined water column and particle trap data clearly indicate that Mn is released from particles as they sink through the oxygen minimum. Rate-of-change estimates based on trap flux data yield regeneration rates of up to 0.44 nmol kg -1 yr -1 in the upper oxygen minimum (120-200 m). However, only 30% of the dissolved Mn in the oxygen minimum appears to be from sinking particulate regeneration; the other 70% probably results from continental-slope-release-horizontal-transport processes. Dissolved Mn scavenges back onto particles as oxygen levels begin to increase with depth. Scavenging rates ranging from -0.03 to -0.09 nmol kg -1 yr -1 were observed at depths from 700 to 1950 m. These scavenging rates result in Mn residence times of 16-19 years, and scavenging rate constants on the order of 0.057 yr -1. Manganese removal via scavenging on sinking particles below the oxygen minimum is balanced by Mn released along continental boundaries and transported horizontally via advective

  12. Ceramic oxygen transport membrane array reactor and reforming method

    DOEpatents

    Kelly, Sean M.; Christie, Gervase Maxwell; Rosen, Lee J.; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-09-27

    A commercially viable modular ceramic oxygen transport membrane reforming reactor for producing a synthesis gas that improves the thermal coupling of reactively-driven oxygen transport membrane tubes and catalyst reforming tubes required to efficiently and effectively produce synthesis gas.

  13. Insensitivity of cerebral oxygen transport to oxygen affinity of hemoglobin-based oxygen carriers

    PubMed Central

    Koehler, Raymond C.; Fronticelli, Clara; Bucci, Enrico

    2008-01-01

    The cerebrovascular effects of exchange transfusion of various cell-free hemoglobins that possess different oxygen affinities are reviewed. Reducing hematocrit by transfusion of a non-oxygen-carrying solution dilates pial arterioles on the brain surface and increases cerebral blood flow to maintain a constant bulk oxygen transport to the brain. In contrast, transfusion of hemoglobins with P50 of 4–34 Torr causes constriction of pial arterioles that offsets the decrease in blood viscosity to maintain cerebral blood flow and oxygen transport. The autoregulatory constriction is dependent on synthesis of 20-HETE from arachidonic acid. This oxygen-dependent reaction is apparently enhanced by facilitated oxygen diffusion from the red cell to the endothelium arising from increased plasma oxygen solubility in the presence of low or high-affinity hemoglobin. Exchange transfusion of recombinant hemoglobin polymers with P50 of 3 and 18 Torr reduces infarct volume from experimental stroke. Cell-free hemoglobins do not require a P50 as high as red blood cell hemoglobin to facilitate oxygen delivery. PMID:18230370

  14. 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.

  15. 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…

  16. Numerical study of oxygen transport in a carotid bifurcation

    NASA Astrophysics Data System (ADS)

    Tada, Shigeru

    2010-07-01

    This study investigates the oxygen mass transport in the region around the human carotid bifurcation, particularly addressing the effects of bifurcation geometry and pulsatile blood flow on the oxygen transport between the blood flow and artery wall tissue, coupled with the metabolic oxygen consumption and oxygen diffusion in the artery wall tissue. The temporal variations and spatial distributions of the oxygen tension are predicted quantitatively using a geometric model of the human carotid bifurcation and realistic blood flow waveforms. Results reveal that the flow separation at the outside wall of the sinus of the internal carotid artery (ICA) can markedly alter the flow pattern, oxygen tension and the oxygen wall flux. Results also clarify that the flow unsteadiness has a secondary effect on the oxygen tension inside the wall. The non-dimensional oxygen flux, the Sherwood number Sh, at the outside wall of the ICA sinus, takes markedly lower values of about 45 than at other sites because the rates of oxygen transport by the convective flow are reduced at the outside wall of the ICA sinus. The transverse distributions of the oxygen tension inside the artery wall show parabolic profiles having minima in the middle of the wall thickness, with the lowest value of 35 mmHg. These predicted distributions of the oxygen tension inside the wall closely resemble those obtained from experiments. The results demonstrate that hypoxic zones appear inside the artery walls at locations where atherosclerotic lesions are prone to develop.

  17. OXYGEN TRANSPORT IN THE MICROCIRCULATION AND ITS REGULATION

    PubMed Central

    Pittman, Roland N.

    2012-01-01

    Cells require energy to carry out their functions and they typically use oxidative phosphorylation to generate the needed ATP. Thus, cells have a continuous need for oxygen which they receive by diffusion from the blood through the interstitial fluid. The circulatory system pumps oxygen-rich blood through a network of increasingly minute vessels, the microcirculation. The structure of the microcirculation is such that all cells have at least one nearby capillary for diffusive exchange of oxygen and red blood cells release the oxygen bound to hemoglobin as they traverse capillaries. This review focuses first on the historical development of techniques to measure oxygen at various sites in the microcirculation, including the blood, interstitium and cells. Next, approaches are described as to how these techniques have been employed to make discoveries about different aspects of oxygen transport. Finally, ways in which oxygen might participate in the regulation of blood flow toward matching oxygen supply to oxygen demand is discussed. Overall, the transport of oxygen to the cells of the body is one of the most critical functions of the cardiovascular system and it is in the microcirculation where the final local determinants of oxygen supply, oxygen demand and their regulation are decided. PMID:23025284

  18. Significance of oxygen transport through aquaporins

    PubMed Central

    Zwiazek, Janusz J.; Xu, Hao; Tan, Xiangfeng; Navarro-Ródenas, Alfonso; Morte, Asunción

    2017-01-01

    Aquaporins are membrane integral proteins responsible for the transmembrane transport of water and other small neutral molecules. Despite their well-acknowledged importance in water transport, their significance in gas transport processes remains unclear. Growing evidence points to the involvement of plant aquaporins in CO2 delivery for photosynthesis. The role of these channel proteins in the transport of O2 and other gases may also be more important than previously envisioned. In this study, we examined O2 permeability of various human, plant, and fungal aquaporins by co-expressing heterologous aquaporin and myoglobin in yeast. Two of the most promising O2-transporters (Homo sapiens AQP1 and Nicotiana tabacum PIP1;3) were confirmed to facilitate O2 transport in the spectrophotometric assay using yeast protoplasts. The over-expression of NtPIP1;3 in yeasts significantly increased their O2 uptake rates in suspension culture. In N. tabacum roots subjected to hypoxic hydroponic conditions, the transcript levels of the O2-transporting aquaporin NtPIP1;3 significantly increased after the seven-day hypoxia treatment, which was accompanied by the increase of ATP levels in the apical root segments. Our results suggest that the functional significance of aquaporin-mediated O2 transport and the possibility of controlling the rate of transmembrane O2 transport should be further explored. PMID:28079178

  19. Significance of oxygen transport through aquaporins.

    PubMed

    Zwiazek, Janusz J; Xu, Hao; Tan, Xiangfeng; Navarro-Ródenas, Alfonso; Morte, Asunción

    2017-01-12

    Aquaporins are membrane integral proteins responsible for the transmembrane transport of water and other small neutral molecules. Despite their well-acknowledged importance in water transport, their significance in gas transport processes remains unclear. Growing evidence points to the involvement of plant aquaporins in CO2 delivery for photosynthesis. The role of these channel proteins in the transport of O2 and other gases may also be more important than previously envisioned. In this study, we examined O2 permeability of various human, plant, and fungal aquaporins by co-expressing heterologous aquaporin and myoglobin in yeast. Two of the most promising O2-transporters (Homo sapiens AQP1 and Nicotiana tabacum PIP1;3) were confirmed to facilitate O2 transport in the spectrophotometric assay using yeast protoplasts. The over-expression of NtPIP1;3 in yeasts significantly increased their O2 uptake rates in suspension culture. In N. tabacum roots subjected to hypoxic hydroponic conditions, the transcript levels of the O2-transporting aquaporin NtPIP1;3 significantly increased after the seven-day hypoxia treatment, which was accompanied by the increase of ATP levels in the apical root segments. Our results suggest that the functional significance of aquaporin-mediated O2 transport and the possibility of controlling the rate of transmembrane O2 transport should be further explored.

  20. 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.

  1. 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.

  2. 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

  3. Computational Model for Oxygen Transport and Consumption in Human Vitreous

    PubMed Central

    Filas, Benjamen A.; Shui, Ying-Bo; Beebe, David C.

    2013-01-01

    Purpose. Previous studies that measured liquefaction and oxygen content in human vitreous suggested that exposure of the lens to excess oxygen causes nuclear cataracts. Here, we developed a computational model that reproduced available experimental oxygen distributions for intact and degraded human vitreous in physiologic and environmentally perturbed conditions. After validation, the model was used to estimate how age-related changes in vitreous physiology and structure alter oxygen levels at the lens. Methods. A finite-element model for oxygen transport and consumption in the human vitreous was created. Major inputs included ascorbate-mediated oxygen consumption in the vitreous, consumption at the posterior lens surface, and inflow from the retinal vasculature. Concentration-dependent relations were determined from experimental human data or estimated from animal studies, with the impact of all assumptions explored via parameter studies. Results. The model reproduced experimental data in humans, including oxygen partial pressure (Po2) gradients (≈15 mm Hg) across the anterior-posterior extent of the vitreous body, higher oxygen levels at the pars plana relative to the vitreous core, increases in Po2 near the lens after cataract surgery, and equilibration in the vitreous chamber following vitrectomy. Loss of the antioxidative capacity of ascorbate increases oxygen levels 3-fold at the lens surface. Homogeneous vitreous degeneration (liquefaction), but not partial posterior vitreous detachment, greatly increases oxygen exposure to the lens. Conclusions. Ascorbate content and the structure of the vitreous gel are critical determinants of lens oxygen exposure. Minimally invasive surgery and restoration of vitreous structure warrant further attention as strategies for preventing nuclear cataracts. PMID:24008409

  4. [Plasmapheresis in haematology].

    PubMed

    Woźniak, Krzysztof; Urbanowska, Elżbieta; Snarski, Emilian

    2015-01-01

    Plasmapheresis also known as a therapeutic plasma exchange (TPE) is a procedure of plasma removal with it's ineligible plasma's component. Usually it is a supportive measure used simultaneously with the treatment, but in a few diseases, e.g. in trombotictrombocytopenic purpura (TTP), it is a first-choice treatment. During the plasmapheresis plasma is mostly replaced by 20% solution of albumin or combination of 20% solution of albumin and 0.9% solution of NaCl, however in some diseases fresh frozen plasma (FFP) is used. Plasmaphereses have found a wide application in different branches of medicine: hematology, neurology, nephrology, reumatology. Plasmapheresis is an invasive procedure, but when performed by qualified staff it is rather safe and serious complications are very rare.The most common complications of plasmapheresis are mild, usually caused by electrolyte disturbances (hypokalemia, hypokalcemia) or anticoagulation. More serious complication can be associated with FFP transfusion, extracorporeal circulation or presence of intravenous catheter. The latter one is usually necessary to perform the plasmapheresis. In haematology the most common indication for plasmapheresis is the supportive treatment of multiple myeloma. The procedure is performed in patients with high protein levels endangered with hyperviscosity syndrome. Less frequent indications to plasmapheresis in haematology are: Waldenström's macroblobulynaemia, idiopathic thrombocytopenic purpura (ITP), pure red cell aplasia (PRCA), polyneuropaties connected with haematological disorders. Supportive treatment of haemofagocytic syndrome (HLH--hemophagocytic lymphohistiocytosis) is one of the new indications. Plasmaphereses are used in treatment of about 150 different diseases and more and more new needs for this method are identified.

  5. 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.

  6. Effective Potential Energies and Transport Properties for Nitrogen and Oxygen

    NASA Technical Reports Server (NTRS)

    Stallcop, James R.; Partridge, Harry; Levin, Eugene; Kwak, Dochan (Technical Monitor)

    2001-01-01

    The results of recent theoretical studies for N--N2, O--O2, N2--N2 interactions are applied to the transport properties of nitrogen and oxygen gases. The theoretical results are used to select suitable oxygen interaction energies from previous work for determining the diffusion and viscosity coefficients at high temperatures. A universal formulation is applied to determine the collision integrals for O2--O2 interactions at high temperatures and to calculate certain ratios for determining higher-order collision integrals.

  7. 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

  8. Strain effects on oxygen transport in tetragonal zirconium dioxide

    SciTech Connect

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2013-11-01

    Temperature accelerated dynamics and molecular dynamics simulations are used to investigate the strain effects on oxygen interstitial and vacancy migration in tetragonal zirconium dioxide. At zero external strain, the anisotropic migration mechanisms of oxygen defects are characterized. At non-zero strains, both the crystal structure and defect migration barriers are modified by strain. Under compressive strains, the defect migration barrier increases with the increasing strain for both interstitials and vacancies. The crystal structure transforms from a tetragonal to a nearly cubic fluorite structure. Accordingly, the defect migration becomes nearly isotropic. Under dilative strains, the migration barrier first decreases then increases with increasing strain for both types of defects. The tetragonal phase transforms to a lower symmetry structure that is close to the orthorhombic phase. In turn, the defect migration becomes highly anisotropic. Under both compressive and dilative strains, interstitials respond to strain more strongly than vacancies. At small dilative strains, an oxygen interstitial has comparable diffusivity to a vacancy, suggesting that both types of defects can contribute to oxygen transport, if they are present. Although currently no previous result is available to validate oxygen interstitial diffusion behavior, the trend of strain effects on oxygen vacancy diffusion is in good agreement with available experimental and theoretical studies in the literature.

  9. Nonsteady State Oxygen Transport in Engineered Tissue: Implications for Design

    PubMed Central

    Ehsan, Seema M.

    2013-01-01

    Engineered tissue constructs are limited in size, and thus clinical relevance, when diffusion is the primary mode of oxygen transport. Understanding the extent of oxygen diffusion and cellular consumption is necessary for the design of engineered tissues, particularly those intended for implantation into hypoxic wound sites. This study presents a combined experimental and computation model to predict design constraints for cellularized fibrin tissues subjected to a step change in the oxygen concentration to simulate transplantation. Nonsteady state analysis of oxygen diffusion and consumption was used to estimate the diffusion coefficient of oxygen (mean±SD, 1.7×10−9±8.4×10−11 m2/s) in fibrin hydrogels as well as the Michaelis-Menten parameters, Vmax (1.3×10−17±9.2×10−19 mol·cell−1·s−1), and Km (8.0×10−3±3.5×0−3 mol/m3), of normal human lung fibroblasts. Nondimensionalization of the governing diffusion-reaction equation enabled the creation of a single dimensionless parameter, the Thiele modulus (φ), which encompasses the combined effects of oxygen diffusion, consumption, and tissue dimensions. Tissue thickness is the design parameter with the most pronounced influence on the distribution of oxygen within the system. Additionally, tissues designed such that φ<1 achieve a near spatially uniform and adequate oxygen concentration following the step change. Understanding and optimizing the Thiele modulus will improve the design of engineered tissue implants. PMID:23350630

  10. Reclaimed wastewater quality enhancement by oxygen injection during transportation.

    PubMed

    Rodríguez-Gómez, L E; Alvarez, M; Rodríguez-Sevilla, J; Marrero, M C; Hernández, A

    2011-01-01

    In-sewer treatments have been studied in sewer systems, but few have been carried out on reclaimed wastewater systems. A study of oxygen injection has been performed in a completely filled gravity pipe, 0.6 m in diameter and 62 km long, in cast iron with concrete inside coating, which is part of the reclaimed wastewater reuse scheme of Tenerife (Spain). A high pressure oxygen injection system was installed at 16.0 km from pipe inlet and a constant dosage of 30 mg/L O(2) has been injected during six months, under three different operational modes (low COD, 63 mg/L; high COD, 91 mg/L; and partially nitrified water). Oxygen has been consumed in nitrification and organic matter reduction. Generally, nitrification is clearly favored instead of the organic matter oxidation. Nitrification occurs, in general, with nitrite accumulation due to the presence of free ammonia above 1 mg/L. Denitrification is in all cases incomplete due to a limitation of easily biodegradable organic matter content, inhibiting the appearance of anaerobic conditions and sulfide generation. A notable reduction of organic matter parameters is achieved (TSS below 10 mg/L), which is significantly higher than that observed under the ordinary transport conditions without oxygen. This leads to a final cost reduction, and the oxygen injection system helps water reuse managers to maintain a final good water quality in the case of a treatment plant malfunction.

  11. Preanalytical phase of sport biochemistry and haematology.

    PubMed

    Banfi, G; Dolci, A

    2003-06-01

    Biochemistry and haematology are more and more important and sometimes crucial in sport medicine for diagnosing, controlling and preventing purposes. The analytical process and the global laboratory quality are heavily influenced by the preanalytical phase, including biological material collection, identification, storage and transport of the specimen, preparation for analyses of the specimen through centrifugation, freezing and thawing, aliquoting and sampling. The increasing interest of sport biochemistry should be linked to a knowledge of principal problems and pitfalls in the preanalytical phase of various parameters, commonly used in following training, diet, and performances of athletes, to avoid misinterpretation of data and to improve usefulness of biochemical investigations. We prepared a practical review of preanalytical aspects of principal analyses applied to the athletes. We include the choice of anticoagulant and its limits for haematological tests, the preparation and manipulation of specimens for hormonological investigation, especially for labile molecules, and for cardiac markers, lactate, cytokines, micronutrients, antioxidant molecules. Preanalytical phase of specimens different from blood are also showed, including urine and saliva, and some aspects of preparation of materials to be analyzed with molecular biology technology are treated. Stability of some analytes, when the parameter is fundamental for the clinical usefulness of the results, is supplied. Preparation of the subjects, however, including the possible influence of physical exercise and biological rhythms on the biochemical and haematological parameters, are not listed.

  12. The future of academic haematology.

    PubMed

    Hay, Deborah; Hatton, Christian S R; Weatherall, David J

    2017-03-01

    Recent advances in the basic medical sciences, particularly cell biology and genomics, have great promise for the future development of all aspects of haematological practice. They will also impinge on the hitherto neglected fields of haematology, including haematology involving the care of the rapidly increasing number of elderly patients and the complex problems of haematological practice in the developing countries. To obtain the maximum benefit from these new developments it will be necessary to review the patterns of training of haematologists of the future at every level. In short, it will be important to try to design and develop various career pathways for training haematologists including those who wish to work full time in basic research, combine research with clinical practice, or commit all their time to clinical work and teaching.

  13. Oxygen transport and consumption during experimental cardiopulmonary bypass using oxyfluor.

    PubMed

    Briceño, J C; Rincón, I E; Vélez, J F; Castro, I; Arcos, M I; Velásquez, C E

    1999-01-01

    To evaluate a perfluorocarbon based oxygen carrier (Oxyfluor), a porcine model of cardiopulmonary bypass (CPB) was implemented. Swine (30 kg) were subjected to 2 h of normothermic CPB using Oxyfluor (OF group, n = 8) or Ringer's lactate (RL group, n = 13) as the prime. Mean arterial pressure (MAP) was kept at 50 mm Hg, flow rate at 80 ml x min(-1) x kg(-1), and PaCO2 at 35 mm Hg. Hemodynamic, hematologic, fluid balance, and blood gasimetry variables were measured. Total body oxygen delivery (DO2), consumption (VO2), and the fractional contribution to delivery (FCD) and to consumption (FCC) of the red blood cells (RBC), PFC, and plasma phases were calculated. Mixed venous PO2 (PvO2) was significantly higher at 30 min and 1 h on CPB in the OF group than in the RL group. FCCRBC was significantly lower at 30 min, 1 h, and 90 min on CPB in the OF group than in the RL group. PvjO2, Ca-vO2, Ca-vj O2, and VO2 were slightly higher in the OF group than in the RL group. Tissue fluid accumulation was not alleviated with Oxyfluor, and tissue and brain acidosis were significantly increased in the OF group. This study presented evidence that Oxyfluor improved tissue oxygenation and total body oxygen consumption during experimental CPB. In addition, Oxyfluor reduced FCCRBC, increasing oxygen transport reserve of the RBC phase, which can be useful to reduce hypoxic events during CPB. Further research should be conducted to optimize PFC-OCs for use in CPB and to reduce secondary effects.

  14. 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.

  15. 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

  16. 78 FR 1765 - Requirements for Chemical Oxygen Generators Installed on Transport Category Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... Federal Aviation Administration 14 CFR Part 25 RIN 2120-AK14 Requirements for Chemical Oxygen Generators... requirements for chemical oxygen generators installed on transport category airplanes so the generators are... Committee COG--Chemical Oxygen Generator LOARC--Lavatory Oxygen Aviation Rulemaking Committee SaO 2...

  17. System and method for air temperature control in an oxygen transport membrane based reactor

    DOEpatents

    Kelly, Sean M

    2016-09-27

    A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  18. System and method for temperature control in an oxygen transport membrane based reactor

    DOEpatents

    Kelly, Sean M.

    2017-02-21

    A system and method for temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  19. 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.

  20. 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

  1. 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.

  2. A model of oxygen transport in Pt/ceria catalysts from isotope exchange

    SciTech Connect

    Holmgren, A.; Andersson, B.; Duprez, D.

    1999-03-10

    From isotope oxygen exchange reactions and simulations of these experiments, the important steps in oxygen transport in Pt/ceria were distinguished and their rates were estimated. A Pt/alumina sample was also experimentally investigated for comparison. Oxygen surface diffusion as well as oxygen spillover from Pt to ceria was found to be fast in comparison with adsorption/desorption of oxygen on the metal and oxygen bulk diffusion. The exchange rate was found to be higher on a very-low-Pt-dispersion sample than on a high-dispersion sample, which in the model was explained by the different adsorption properties of oxygen.

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

    DOE PAGES

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

    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. 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.

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

    PubMed

    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.

  7. 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. PMID:27630556

  8. The effect of myoglobin-facilitated oxygen transport on the basal metabolism of papillary muscle.

    PubMed Central

    Loiselle, D S

    1987-01-01

    A mathematical model of oxygen diffusion into cylindrical papillary muscles is presented. The model partitions total oxygen flux into its simple and myoglobin-facilitated components. The model includes variable sigmoidal, exponential, or hyperbolic functions relating oxygen partial pressure to both fractional myoglobin saturation and rate of oxygen consumption. The behavior of the model was explored for a variety of saturation- and consumption-concentration relations. Facilitation of oxygen transport by myoglobin was considerable as indexed both by the elevation of oxygen partial pressure on the longitudinal axis of the muscle and by the fraction of total oxygen flux at the muscle center contributed by oxymyoglobin. Despite its facilitation of oxygen flux at the muscle center, myoglobin made only a negligible contribution to the total oxygen consumption averaged over the muscle cross-section. Hence the presence of myoglobin fails to explain either the experimentally determined basal metabolism-muscle radius relation or the stretch effect observed in isolated papillary muscle. PMID:3607211

  9. Oxygen transport in an in-situ bioremediation application

    SciTech Connect

    Gupta, S.K.; Djafari, S.H.; Zhang, J.

    1995-11-01

    Contamination of groundwater and soils by toxic organic chemicals is widespread and poses serious health and environmental problems. The area under study is comprised of lagoons containing waste from former coking plant operations. The primary contaminants of concern in the waste are the polycyclic aromatic hydrocarbons (PAHs). Due to their hydrophobicity, these compounds tend to partition into hydrophobic adsorbents such as soil organic matter. In the presence of appropriate microorganisms, the biodegradation of higher molecular weight PAHs (with more than three benzene rings) is relatively slow, and generally involves cometabolism. The PAH compounds in general have been shown to be biodegradable and site-specific treatability tests have indicated that bioremediation has been effective in reducing PAH contamination levels at the study site. The subsurface permeability must be sufficient to allow for perfusion with solutions of oxygen and nutrients as required for biodegradation processes. Sources of oxygen that may e used include air (which has approximately 20% oxygen content), hydrogen peroxide (which releases oxygen through dissociation), and pure oxygen (industrially produced oxygen with greater than 90% purity). The stability of hydrogen peroxide in the presence of lagoon materials was evaluated during the predesign investigation conducted at the study site. The half-lives of hydrogen peroxide which were found to be between 20 minutes and 3 hours for the lagoon wastes, were determined to be marginal. Alternative oxygen sources considered included the use of air and pure oxygen.

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

    PubMed

    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

  11. 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...

  12. Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream

    DOEpatents

    Kromer, Brian R.; Litwin, Michael M.; Kelly, Sean M.

    2016-09-27

    A method and system for generating electrical power in which a high pressure synthesis gas stream generated in a gasifier is partially oxidized in an oxygen transport membrane based reactor, expanded and thereafter, is combusted in an oxygen transport membrane based boiler. A low pressure synthesis gas slip stream is split off downstream of the expanders and used as the source of fuel in the oxygen transport membrane based partial oxidation reactors to allow the oxygen transport membrane to operate at low fuel pressures with high fuel utilization. The combustion within the boiler generates heat to raise steam to in turn generate electricity by a generator coupled to a steam turbine. The resultant flue gas can be purified to produce a carbon dioxide product.

  13. Solute transport and oxygen consumption along the nephrons: effects of Na+ transport inhibitors.

    PubMed

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

    2016-12-01

    Sodium and its associated anions are the major determinant of extracellular fluid volume, and the reabsorption of Na(+) by the kidney plays a crucial role in long-term blood pressure control. The goal of this study was to investigate the extent to which inhibitors of transepithelial Na(+) transport (TNa) along the nephron alter urinary solute excretion and TNa efficiency and how those effects may vary along different nephron segments. To accomplish that goal, we used the multinephron model developed in the companion study (28). That model represents detailed transcellular and paracellular transport processes along the nephrons of a rat kidney. We simulated the inhibition of the Na(+)/H(+) exchanger (NHE3), the bumetanide-sensitive Na(+)-K(+)-2Cl(-) transporter (NKCC2), the Na(+)-Cl(-) cotransporter (NCC), and the amiloride-sensitive Na(+) channel (ENaC). Under baseline conditions, NHE3, NKCC2, NCC, and ENaC reabsorb 36, 22, 4, and 7%, respectively, of filtered Na(+) The model predicted that inhibition of NHE3 substantially reduced proximal tubule TNa and oxygen consumption (QO2 ). Whole-kidney TNa efficiency, as reflected by the number of moles of Na(+) reabsorbed per moles of O2 consumed (denoted by the ratio TNa/QO2 ), decreased by ∼20% with 80% inhibition of NHE3. NKCC2 inhibition simulations predicted a substantial reduction in thick ascending limb TNa and QO2 ; however, the effect on whole-kidney TNa/QO2 was minor. Tubular K(+) transport was also substantially impaired, resulting in elevated urinary K(+) excretion. The most notable effect of NCC inhibition was to increase the excretion of Na(+), K(+), and Cl(-); its impact on whole-kidney TNa and its efficiency was minor. Inhibition of ENaC was predicted to have opposite effects on the excretion of Na(+) (increased) and K(+) (decreased) and to have only a minor impact on whole-kidney TNa and TNa/QO2 Overall, model predictions agree well with measured changes in Na(+) and K(+) excretion in response to

  14. Numerical model of fluid flow and oxygen transport in a radial-flow microchannel containing hepatocytes.

    PubMed

    Ledezma, G A; Folch, A; Bhatia, S N; Balis, U J; Yarmush, M L; Toner, M

    1999-02-01

    The incorporation of monolayers of cultured hepatocytes into an extracorporeal perfusion system has become a promising approach for the development of a temporary bioartificial liver (BAL) support system. In this paper we present a numerical investigation of the oxygen tension, shear stress, and pressure drop in a bioreactor for a BAL composed of plasma-perfused chambers containing monolayers of porcine hepatocytes. The chambers consist of microfabricated parallel disks with center-to-edge radial flow. The oxygen uptake rate (OUR), measured in vitro for porcine hepatocytes, was curve-fitted using Michaelis-Menten kinetics for simulation of the oxygen concentration profile. The effect of different parameters that may influence the oxygen transport inside the chambers, such as the plasma flow rate, the chamber height, the initial oxygen tension in the perfused plasma, the OUR, and K(m) was investigated. We found that both the plasma flow rate and the initial oxygen tension may have an important effect upon oxygen transport. Increasing the flow rate and/or the inlet oxygen tension resulted in improved oxygen transport to cells in the radial-flow microchannels, and allowed significantly greater diameter reactor without oxygen limitation to the hepatocytes. In the range investigated in this paper (10 microns < H < 100 microns), and for a constant plasma flow rate, the chamber height, H, had a negligible effect on the oxygen transport to hepatocytes. On the contrary, it strongly affected the mechanical stress on the cells that is also crucial for the successful design of the BAL reactors. A twofold decrease in chamber height from 50 to 25 microns produced approximately a fivefold increase in maximal shear stress at the inlet of the reactor from 2 to 10 dyn/cm2. Further decrease in chamber height resulted in shear stress values that are physiologically unrealistic. Therefore, the channel height needs to be carefully chosen in a BAL design to avoid deleterious hydrodynamic

  15. Water flow influences oxygen transport and photosynthetic efficiency in corals

    NASA Astrophysics Data System (ADS)

    Finelli, Christopher M.; Helmuth, Brian S. T.; Pentcheff, N. Dean; Wethey, David S.

    2006-03-01

    Recent studies indicate that the incidence and persistence of damage from coral reef bleaching are often highest in areas of restricted water motion, and that resistance to and recovery from bleaching is increased by enhanced water motion. We examined the hypothesis that water motion increases the efflux of oxygen from coral tissue thereby reducing oxidative stress on the photosynthetic apparatus of endosymbiotic zooxanthellae. We experimentally exposed colonies of Montastrea annularis and Agaricia agaricites to manipulations of water flow, light intensity, and oxygen concentration in the field using a novel mini-flume. We measured photosynthetic efficiency using a pulse amplitude modulated fluorometer to test the short-term response of corals to our manipulations. Under normal oxygen concentrations, A. agaricites showed a significant 8% increase in photosynthetic efficiency from 0.238 (± 0.032) in still water to 0.256 (± 0.037) in 15 cm s-1 flow, while M. annularis exhibited no detectable change. Under high-ambient oxygen concentrations, the observed effect of flow on A. agaricites was reversed: photosynthetic efficiencies showed a significant 11% decrease from 0.236 (± 0.056) in still water to 0.211 (± 0.048) in 15 cm s-1 flow. These results support the hypothesis that water motion helps to remove oxygen from coral tissues during periods of maximal photosynthesis. Flow mitigation of oxidative stress may at least partially explain the increased incidence and severity of coral bleaching in low flow areas and observations of enhanced recovery in high-flow areas.

  16. Oxygen Transport Characterization of a Human Model of Progressive Hemorrhage

    DTIC Science & Technology

    2010-01-01

    Continuous heart rate (HR) wasmeasured from a standard elec- trocardiogram (ECG). Continuous , beat-by-beat blood pressurewas measured noninvasively...breathing room air.15 2.7. Tissue oxygenation measurements Muscle tissue SO2 was measured using a near infrared spec- troscopy (NIRS) monitor developed...Non-invasive continuous finger blood pressure measurement during ortho- static stress compared to intra-arterial pressure. Cardiovasc Res 1990;24

  17. 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.

  18. Regulation of blood oxygen transport in hibernating mammals.

    PubMed

    Revsbech, Inge G; Fago, Angela

    2017-03-21

    Along with the periodic reductions in O2 requirements of mammalian hibernators during winter, the O2 affinity of the blood of mammalian hibernators is seasonally regulated to help match O2 supply to consumption, contributing to limit tissue oxidative stress, particularly at arousals. Specifically, mammalian hibernators consistently show an overall increase in the blood-O2 affinity, which causes a decreased O2 unloading to tissues, while having similar or lower tissue O2 tensions during hibernation. This overview explores how the decreased body temperature and concentration of red blood cell 2,3-diphosphoglycerate (DPG) that occur in hibernation contribute separately or in combination to the concurrent increase in the O2 affinity of the hemoglobin, the O2 carrier protein of the blood. Most mammalian hemoglobins are responsive to changes in DPG concentrations, including that of the hibernating brown bear, although the smaller hibernators, such as golden-mantled ground squirrel, chipmunks, and dormice, have hemoglobins with low sensitivity to DPG. While the effect of DPG on oxygenation may vary, the decrease in body temperature invariably increases hemoglobin's O2 affinity in all hibernating species. However, the temperature sensitivity of hemoglobin oxygenation is low in hibernators compared to human, apparently due in part to endothermic allosteric quaternary transition in ground squirrels and dissociation of chloride ions in brown bears. A low heat of blood oxygenation in temporal heterotherms, like hibernators, may thus contribute to reduce heat loss, as found in regional heterotherms, like polar mammals, although the significance would be low in winter hibernation.

  19. 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

  20. Oxygen transport in unreduced, reduced and Rh(III)-doped CeO2 nanocrystals.

    PubMed

    Sayle, Thi X T; Parker, Stephen C; Sayle, Dean C

    2007-01-01

    Ceria, CeO2, based materials are a major (active) component of exhaust catalysts and promising candidates for solid oxide fuel cells. In this capacity, oxygen transport through the material is pivotal. Here, we explore whether oxygen transport is influenced (desirably increased) compared with transport within the bulk parent material by traversing to the nanoscale. In particular, atomistic models for ceria nanocrystals, including perfect: CeO2; reduced: CeO1.95 and doped: Rh0.1Ce0.9O1.95, have been generated. The nanocrystals were about 8 nm in diameter and each comprised about 16,000 atoms. Oxygen transport can also be influenced, sometimes profoundly, by microstructural features such as dislocations and grain-boundaries. However, these are difficult to generate within an atomistic model using, for example, symmetry operations. Accordingly, we crystallised the nanocrystals from an amorphous precursor, which facilitated the evolution of a variety of microstructures including: twin-boundaries and more general grain-boundaries and grain-junctions, dislocations and epitaxy, isolated and associated point defects. The shapes of the nanocrystals are in accord with HRTEM data and comprise octahedral morphologies with {111} surfaces, truncated by (dipolar) {100} surfaces together with a complex array of steps, edges and corners. Oxygen transport data was then calculated using these models and compared with data calculated previously for CeO1.97/ YSZ thin films and the (bulk) parent material, CeO197. Oxygen transport was calculated to increase in the order: CeO2 nanocrystal < (reduced) CeO1.95 nanocrystal approximately Rh0.1Ce0.9O1.95 nanocrystal < CeO1.97/YSZ thin film < (reduced) CeO1.97 (bulk) parent material; the mechanism was determined to be primarily vacancy driven. Our findings indicate that reducing one- (thin film) or especially three- (nanocrystal) dimensions to the nanoscale may prove deleterious to oxygen transport. Conversely, we observed dynamic evolution and

  1. 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.

  2. 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

    2007-08-03

    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.

  3. Saturation-recovery electron paramagnetic resonance discrimination by oxygen transport (DOT) method for characterizing membrane domains.

    PubMed

    Subczynski, Witold K; Widomska, Justyna; Wisniewska, Anna; Kusumi, Akihiro

    2007-01-01

    The discrimination by oxygen transport (DOT) method is a dual-probe saturation-recovery electron paramagnetic resonance approach in which the observable parameter is the spin-lattice relaxation time (T1) of lipid spin labels, and the measured value is the bimolecular collision rate between molecular oxygen and the nitroxide moiety of spin labels. This method has proven to be extremely sensitive to changes in the local oxygen diffusion-concentration product (around the nitroxide moiety) because of the long T1 of lipid spin labels (1-10 micros) and also because molecular oxygen is a unique probe molecule. Molecular oxygen is paramagnetic, small, and has the appropriate level of hydrophobicity that allows it to partition into various supramolecular structures such as different membrane domains. When located in two different membrane domains, the spin label alone most often cannot differentiate between these domains, giving very similar (indistinguishable) conventional electron paramagnetic resonance spectra and similar T1 values. However, even small differences in lipid packing in these domains will affect oxygen partitioning and oxygen diffusion, which can be easily detected by observing the different T1s from spin labels in these two locations in the presence of molecular oxygen. The DOT method allows one not only to distinguish between the different domains, but also to obtain the value of the oxygen diffusion-concentration product in these domains, which is a useful physical characteristic of the organization of lipids in domains. Profiles of the oxygen diffusion-concentration product (the oxygen transport parameter) in coexisting domains can be obtained in situ without the need for the physical separation of the two domains. Furthermore, under optimal conditions, the exchange rate of spin-labeled molecules between the two domains could be measured.

  4. Oxygen consumption rates in subseafloor basaltic crust derived from a reaction transport model.

    PubMed

    Orcutt, Beth N; Wheat, C Geoffrey; Rouxel, Olivier; Hulme, Samuel; Edwards, Katrina J; Bach, Wolfgang

    2013-01-01

    Oceanic crust is the largest potential habitat for life on Earth and may contain a significant fraction of Earth's total microbial biomass; yet, empirical analysis of reaction rates in basaltic crust is lacking. Here we report the first assessment of oxygen consumption in young (~8 Ma) and cool (<25 °C) basaltic crust, which we calculate from modelling dissolved oxygen and strontium pore water gradients in basal sediments collected during Integrated Ocean Drilling Program Expedition 336 to 'North Pond' on the western flank of the Mid-Atlantic Ridge. Dissolved oxygen is completely consumed within the upper to middle section of the sediment column, with an increase in concentration towards the sediment-basement interface, indicating an upward supply from oxic fluids circulating within the crust. A parametric reaction transport model of oxygen behaviour in upper basement suggests oxygen consumption rates of 1 nmol  cm(-3)ROCK d(-1) or less in young and cool basaltic crust.

  5. Hemoglobin-based oxygen carrier and convection enhanced oxygen transport in a hollow fiber bioreactor.

    PubMed

    Chen, Guo; Palmer, Andre F

    2009-04-15

    A mathematical model was developed to study O(2) transport in a convection enhanced hepatic hollow fiber (HF) bioreactor, with hemoglobin-based O(2) carriers (HBOCs) present in the flowing cell culture media stream of the HF lumen. In this study, four HBOCs were evaluated: PEG-conjugated human hemoglobin (MP4), human hemoglobin (hHb), bovine hemoglobin (BvHb) and polymerized bovine hemoglobin (PolyBvHb). In addition, two types of convective flow in the HF extra capillary space (ECS) were considered in this study. Starling flow naturally occurs when both of the ECS ports are closed. If one of the ECS ports is open, forced convective flow through the ECS will occur due to the imposed pressure difference between the lumen and ECS. This type of flow is referred to as cross-flow in this work, since some of the fluid entering the HF lumen will pass across the HF membrane and exit via the open ECS port. In this work, we can predict the dissolved O(2) concentration profile as well as the O(2) transport flux in an individual HF of the bioreactor by solving the coupled momentum and mass transport equations. Our results show that supplementation of the cell culture media with HBOCs can dramatically enhance O(2) transport to the ECS (containing hepatocytes) and lead to the formation of an in vivo-like O(2) spectrum for the optimal culture of hepatocytes. However, both Starling flow and cross-flow have a very limited effect on O(2) transport in the ECS. Taken together, this work represents a novel predictive tool that can be used to design or analyze HF bioreactors that expose cultured cells to defined overall concentrations and gradients of O(2).

  6. 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.

  7. Oxygen transport and intracellular bioenergetics on stimulated cat skeletal muscle.

    PubMed

    Nioka, S; McCully, K; McClellan, G; Park, Jane; Chance, B

    2003-01-01

    A unique multiparameter recording of skeletal muscle bioenergetics, biochemistry and biomechanics has permitted determination of novel relationships among hemodynamics, cellular high-energy metabolites and mitochondrial bioenergetics in feline skeletal muscle. The study utilizes 31P NMR, NIR, and NADH fluorescence spectrophotometry, biochemical assays and muscle performance. Seven cats were anesthetized and mechanically ventilated. Calf muscles were stimulated through sciatic nerve electrical stimulation and tension was monitored by a strain gauge connected to the Achilles tendon. We stimulated the muscle to produce several workloads up to Vmax. We also changed FiO2 from normoxia to hypoxia for each %Vmax. From these results, the most sensitive indicators of cellular hypoxia leading to a reduction in muscle performance can be determined. Hemoglobin deoxygenation generally does not correlate with cellular hypoxia, although when the HbO2 drops below 30% saturation there is an increased incidence of cellular hypoxia. The [ADP], which is known to regulate mitochondrial function, has a close relation to the work, not to the hypoxia. On the other hand, the mitochondrial NADH does respond to cellular PO2. The degree of oxidation (NADH decrease) due to the ATP flux shifts with oxygen availability in mild to moderate hypoxia (at FiO2 down to 9%). As cellular hypoxia causes decreases in muscle performance (moderate to severe hypoxia), NADH is being reduced rather than oxidized with increasing workloads.

  8. Interhospital Transport System for Critically Ill Patients: Mobile Extracorporeal Membrane Oxygenation without a Ventilator

    PubMed Central

    Yeo, Hye Ju; Cho, Woo Hyun; Park, Jong Myung; Kim, Dohyung

    2017-01-01

    Background Extracorporeal membrane oxygenation (ECMO) has been successfully used as a method for the interhospital transportation of critically ill patients. In South Korea, a well-established ECMO interhospital transport system is lacking due to limited resources. We developed a simplified ECMO transport system without mechanical ventilation for use by public emergency medical services. Methods Eighteen patients utilized our ECMO transport system from December 2011 to September 2015. We retrospectively analyzed the indications for ECMO, the patient status during transport, and the patient outcomes. Results All transport was conducted on the ground by ambulance. The distances covered ranged from 26 to 408 km (mean, 65.9±88.1 km) and the average transport time was 56.1±57.3 minutes (range, 30 to 280 minutes). All patients were transported without adverse events. After transport, 4 patients (22.2%) underwent lung transplantation because of interstitial lung disease. Eight patients who had severe acute respiratory distress syndrome showed recovery of heart and lung function after ECMO therapy. A total of 13 patients (70.6%) were successfully taken off ECMO, and 11 patients (61.1%) survived. Conclusion Our ECMO transport system without mechanical ventilation can be considered a safe and useful method for interhospital transport and could be a good alternative option for ECMO transport in Korean hospitals with limited resources. PMID:28180097

  9. Oxygen transport in conscious newborn dogs during hypoxic hypometabolism.

    PubMed

    Rohlicek, C V; Saiki, C; Matsuoka, T; Mortola, J P

    1998-03-01

    We questioned whether the decrease in O2 consumption (VO2) during hypoxia in newborns is a regulated response or reflects a limitation in O2 availability. Experiments were conducted on previously instrumented conscious newborn dogs. VO2 was measured at a warm ambient temperature (30 degrees C, n = 7) or in the cold (20 degrees C, n = 6), while the animals breathed air or were sequentially exposed to 15 min of fractional inspired O2 (FIO2): 21, 18, 15, 12, 10, 8, and 6%. In normoxia, VO2 averaged 15 +/- 1 (SE) and 25 +/- 1 ml . kg-1 . min-1 in warm and cold conditions, respectively. In the warm condition, hypometabolism (i.e., hypoxic VO2 < normoxic VO2) occurred at FIO2 oxygenation. The results do not support the possibility that the hypoxic drop in VO2 in the newborn reflects a limitation in O2 availability. The results are compatible with the idea that the phenomenon is one of "regulated conformism" to hypoxia.

  10. Oxygen Transport Kinetics in Infiltrated SOFCs Cathode by Electrical Conductivity Relaxation Technique

    SciTech Connect

    Li, Yihong; Gerdes, Kirk; Liu, Xingbo

    2013-07-01

    Infiltration has attracted increasing attention as an effective technique to modify SOFC cathodes to improve cell electrochemical performance while maintaining material compatibility and long-term stability. However, the infiltrated material's effect on oxygen transport is still not clear and detailed knowledge of the oxygen reduction reaction in infiltrated cathodes is lacking. In this work, the technique of electrical conductivity relaxation (ECR) is used to evaluate oxygen exchange in two common infiltrated materials, Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9} and La{sub 0.6}Sr{sub 0.4}CoO{sub 3-δ}. The ECR technique is also used to examine the transport processes in a composite material formed with a backbone of La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-δ} and possessing a thin, dense surface layer composed of the representative infiltrate material. Both the surface oxygen exchange process and the oxygen exchange coefficient at infiltrate/LSCF interface are reported. ECR testing results indicate that the application of infiltrate under certain oxygen partial pressure conditions produces a measureable increase in the fitted oxygen exchange parameter. It is presently only possible to generate hypotheses to explain the observation. However the correlation between improved electrochemical performance and increased oxygen transport measured by ECR is reliably demonstrated. The simple and inexpensive ECR technique is utilized as a direct method to optimize the selection of specific infiltrate/backbone material systems for superior performance.

  11. Is the mammalian cell plasma membrane a barrier to oxygen transport?

    PubMed Central

    1992-01-01

    Oxygen transport in the Chinese hamster ovary (CHO) plasma membrane has been studied by observing the collision of molecular oxygen with nitroxide radical spin labels placed in the lipid bilayer portion of the membrane at various distances from the membrane surface using the long-pulse saturation-recovery electron spin resonance (ESR) technique. The collision rate was estimated for 5-, 12-, and 16-doxylstearic acids from spin-lattice relaxation times (T1) measured in the presence and absence of molecular oxygen. Profiles of the local oxygen transport parameters across the membrane were obtained showing that the oxygen diffusion-concentration product is lower than in water for all locations at 37 degrees C. From oxygen transport parameter profiles, the membrane oxygen permeability coefficients were estimated according to the procedure developed earlier by Subczynski et al. (Subczynski, W. K., J. S. Hyde, and A. Kusumi. 1989. Proceedings of the National Academy of Sciences, USA. 86:4474-4478). At 37 degrees C, the oxygen permeability coefficient for the plasma membrane was found to be 42 cm/s, about two times lower than for a water layer of the same thickness as the membrane. The oxygen concentration difference across the CHO plasma membrane at physiological conditions is in the nanomolar range. It is concluded that oxygen permeation across the cell plasma membrane cannot be a rate-limiting step for cellular respiration. Correlations of the form PM = cKs between membrane permeabilities PM of small nonelectrolyte solutes of mol wt less than 50, including oxygen, and their partition coefficients K into hexadecane and olive oil are reported. Hexadecane: c = 26 cm/s, s = 0.95; olive oil: c = 23 cm/s, s = 1.56. These values of c and s differ from those reported in the literature for solutes of 50 less than mol wt less than 300 (Walter, A., and J. Gutknecht. 1986. Journal of Membrane Biology. 90:207-217). It is concluded that oxygen permeability through membranes can be

  12. Thermophysical properties and oxygen transport in (Thx,Pu1‑x)O2

    NASA Astrophysics Data System (ADS)

    Galvin, C. O. T.; Cooper, M. W. D.; Rushton, M. J. D.; Grimes, R. W.

    2016-10-01

    Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1‑x)O2 (0 ≤ x ≤ 1) between 300–3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Thx,Pu1‑x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen diffusivity for (Thx,Pu1‑x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1‑x)O2 than PuO2 and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder.

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

    PubMed Central

    Elliott, S

    2008-01-01

    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

  14. Thermophysical properties and oxygen transport in (Thx,Pu1-x)O2

    DOE PAGES

    Galvin, C. O. T.; Cooper, M. W. D.; Rushton, M. J. D.; ...

    2016-10-31

    Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1–x)O2 (0 ≤ x ≤ 1) between 300–3500 K. Specifically, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Thx,Pu1–x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increasemore » in oxygen diffusivity for (Thx,Pu1–x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1–x)O2 than PuO2 and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder.« less

  15. Thermophysical properties and oxygen transport in (Thx,Pu1−x)O2

    PubMed Central

    Galvin, C. O. T.; Cooper, M. W. D.; Rushton, M. J. D.; Grimes, R. W.

    2016-01-01

    Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1−x)O2 (0 ≤ x ≤ 1) between 300–3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Thx,Pu1−x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen diffusivity for (Thx,Pu1−x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1−x)O2 than PuO2 and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder. PMID:27796314

  16. Vasculature based model for characterizing the oxygen transport in skin tissues - analogy to the Weinbaum-Jiji bioheat equation

    NASA Astrophysics Data System (ADS)

    Ji, Yan; Liu, Jing

    Based on the conceptual three-layer microvascular structure of skin tissues proposed by Weinbaum et al. [20-25] and in analogy to the well known Weinbaum-Jiji (W-J) bioheat equation, a new oxygen transport model was established in this paper, which collectively included the contributions of the vascular geometry and the blood flow condition. The new one-dimensional three-layer oxygen transport model was then applied to predict the average oxygen concentration distribution in skin tissues and numerical solutions for the boundary value problem coupling the three layers were obtained. A simple expression for the tensor diffusivity (Deff) of oxygen transport over the deep tissue layer was presented, which was orders of magnitude higher than the intrinsic diffusivity (Dt) in tissue without blood flow. Effects of blood flow velocity and vascular geometry to the oxygen transport were investigated. Calculations indicated that the vascular geometry had significant effects on oxygen transport. The oxygen exchange between the arteries and veins was relatively small for the deep tissue layer. Further, the average oxygen concentration gradient appears low in intermediate layer due to large capillary perfusion. The theoretical results were implemented to interpret some previous experimental results and a better understanding on the oxygen transport across the vascularized living tissues was obtained. The strategy proposed in this paper may provide a feasible way to comprehensively characterize the oxygen transport behaviors in living tissues with real and complex vasculature.

  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 dissection of oxygen transport resistance in the components of a polymer electrolyte membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Oh, Hwanyeong; Lee, Yoo il; Lee, Guesang; Min, Kyoungdoug; Yi, Jung S.

    2017-03-01

    Oxygen transport resistance is a major obstacle for obtaining high performance in a polymer electrolyte membrane fuel cell (PEMFC). To distinguish the major components that inhibit oxygen transport, an experimental method is established to dissect the oxygen transport resistance of the components of the PEMFC, such as the substrate, micro-porous layer (MPL), catalyst layer, and ionomer film. The Knudsen numbers are calculated to determine the types of diffusion mechanisms at each layer by measuring the pore sizes with either mercury porosimetry or BET analysis. At the under-saturated condition where condensation is mostly absent, the molecular diffusion resistance is dissected by changing the type of inert gas, and ionomer film permeation is separated by varying the inlet gas humidity. Moreover, the presence of the MPL and the variability of the substrate thickness allow the oxygen transport resistance at each component of a PEMFC to be dissected. At a low relative humidity of 50% and lower, an ionomer film had the largest resistance, while the contribution of the MPL was largest for the other humidification conditions.

  19. Transcription of hexose transporters of Saccharomyces cerevisiae is affected by change in oxygen provision

    PubMed Central

    Rintala, Eija; Wiebe, Marilyn G; Tamminen, Anu; Ruohonen, Laura; Penttilä, Merja

    2008-01-01

    Background The gene family of hexose transporters in Saccharomyces cerevisiae consists of 20 members; 18 genes encoding transporters (HXT1-HXT17, GAL2) and two genes encoding sensors (SNF3, RGT2). The effect of oxygen provision on the expression of these genes was studied in glucose-limited chemostat cultivations (D = 0.10 h-1, pH 5, 30°C). Transcript levels were measured from cells grown in five steady state oxygen levels (0, 0.5, 1, 2.8 and 20.9% O2), and from cells under conditions in which oxygen was introduced to anaerobic cultures or removed from cultures receiving oxygen. Results The expression pattern of the HXT gene family was distinct in cells grown under aerobic, hypoxic and anaerobic conditions. The transcription of HXT2, HXT4 and HXT5 was low when the oxygen concentration in the cultures was low, both under steady state and non-steady state conditions, whereas the expression of HXT6, HXT13 and HXT15/16 was higher in hypoxic than in fully aerobic or anaerobic conditions. None of the HXT genes showed higher transcript levels in strictly anaerobic conditions. Expression of HXT9, HXT14 and GAL2 was not detected under the culture conditions studied. Conclusion When oxygen becomes limiting in a glucose-limited chemostat cultivation, the glucose uptake rate per cell increases. However, the expression of none of the hexose transporter encoding genes was increased in anaerobic conditions. It thus seems that the decrease in the moderately low affinity uptake and consequently the relative increase of high affinity uptake may itself allow the higher specific glucose consumption rate to occur in anaerobic compared to aerobic conditions. PMID:18373847

  20. 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.

  1. Blood Flow and Oxygen Transport Past an Elliptical Fiber in an Artificial Lung

    NASA Astrophysics Data System (ADS)

    Zierenberg, Jennifer; Fujioka, Hideki; Hirschl, Ronald; Bartlett, Robert; Grotberg, James

    2007-11-01

    Artificial lungs are currently being developed to serve as bridges to lung transplantation with circular fibers, which are permeable to oxygen, used as the transport surface. Blood flows across the fibers while oxygen flows through the fiber lumen. The present work investigates the novel approach of using elliptical fibers as the transport medium. Steady blood flow, modeled as a Casson fluid, and oxygen transport over a single fiber are investigated for varying elliptic aspect ratios (Ar=minor radius/major radius) and orientations to flow (φ). The parameters investigated are Re = 1, 5, 10; Ar = 0.25, 0.5, 0.75, 1; φ= 0^o, 15^o, 30^o, 45^o, 60^o, 75^o, 90^o; and Sc = 1000. The Casson properties of blood decrease the size and strength of recirculation(s) which when present are attached to the downstream side of the fiber. A maximum decrease of 24% in drag and an increase of 10% in transport are observed for Re = 5, Ar = 0.25 and φ= 0^o as compared to the circular fiber. The elliptic properties can thus aid in the design of artificial lungs.

  2. 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.

  3. 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

  4. Oxygen reduction and transportation mechanisms in solid oxide fuel cell cathodes

    NASA Astrophysics Data System (ADS)

    Li, Yihong; Gemmen, Randall; Liu, Xingbo

    In recent years, various models have been developed for describing the reaction mechanisms in solid oxide fuel cell (SOFC) especially for the cathode electrode. However, many fundamental issues regarding the transport of oxygen and electrode kinetics have not been fully understood. This review tried to summarize the present status of the SOFC cathode modeling efforts, and associated experimental approaches on this topic. In addition, unsolved problems and possible future research directions for SOFC cathode kinetics had been discussed.

  5. Oxygen reduction and transportation mechanisms in solid oxide fuel cell cathodes

    SciTech Connect

    Li YH, Gemmen R, Liu XB

    2010-06-01

    In recent years, various models have been developed for describing the reaction mechanisms in solid oxide fuel cell (SOFC) especially for the cathode electrode. However, many fundamental issues regarding the transport of oxygen and electrode kinetics have not been fully understood. This review tried to summarize the present status of the SOFC cathode modeling efforts, and associated experimental approaches on this topic. In addition, unsolved problems and possible future research directions for SOFC cathode kinetics had been discussed

  6. Emerging technologies for non-invasive quantification of physiological oxygen transport in plants.

    PubMed

    Chaturvedi, P; Taguchi, M; Burrs, S L; Hauser, B A; Salim, W W A W; Claussen, J C; McLamore, E S

    2013-09-01

    Oxygen plays a critical role in plant metabolism, stress response/signaling, and adaptation to environmental changes (Lambers and Colmer, Plant Soil 274:7-15, 2005; Pitzschke et al., Antioxid Redox Signal 8:1757-1764, 2006; Van Breusegem et al., Plant Sci 161:405-414, 2001). Reactive oxygen species (ROS), by-products of various metabolic pathways in which oxygen is a key molecule, are produced during adaptation responses to environmental stress. While much is known about plant adaptation to stress (e.g., detoxifying enzymes, antioxidant production), the link between ROS metabolism, O2 transport, and stress response mechanisms is unknown. Thus, non-invasive technologies for measuring O2 are critical for understanding the link between physiological O2 transport and ROS signaling. New non-invasive technologies allow real-time measurement of O2 at the single cell and even organelle levels. This review briefly summarizes currently available (i.e., mainstream) technologies for measuring O2 and then introduces emerging technologies for measuring O2. Advanced techniques that provide the ability to non-invasively (i.e., non-destructively) measure O2 are highlighted. In the near future, these non-invasive sensors will facilitate novel experimentation that will allow plant physiologists to ask new hypothesis-driven research questions aimed at improving our understanding of physiological O2 transport.

  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. Remote cannulation and extracorporeal membrane oxygenation transport is safe in a newly established program

    PubMed Central

    Grenda, David S.; Moll, Vanessa; Kalin, Craig M.

    2017-01-01

    Extracorporeal membrane oxygenation (ECMO) has become an increasingly utilized modality for the support of patients with severe cardiac or pulmonary dysfunction. Unfortunately, the costs and expertise required to maintain a formal ECMO program preclude the vast majority of hospitals from employing such technology routinely. These barriers to implementation of an effective ECMO program highlight the importance of the safe transport of patients in need of extracorporeal support. While many centers with extensive expertise in the management of patients on extracorporeal support have demonstrated their ability to transport those same patients, the ability of new ECMO programs to provide such transportation remains poorly studied. We established an ECMO program at our institution and immediately provided equipment and personnel to transport patients in need of or receiving extracorporeal support to our institution. Overall, we found that 13 out of 28 patients transported to our institution on ECMO or for consideration of ECMO support during the first 15 months of the program survived to hospital discharge. During that period, four incidents associated with patient transport occurred but none were related to ECMO support or adversely affected patient outcome. These observations demonstrate that new ECMO programs can safely and reliably transport patients on or in need of extracorporeal support. PMID:28275616

  9. 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.

  10. Development of a new interfacility extracorporeal membrane oxygenation transport program for pediatric lung transplantation evaluation

    PubMed Central

    Shepherd, Edward G.; Gee, Samantha W.

    2017-01-01

    Pediatric lung transplantation is a life-saving intervention for children with irreversible end-stage lung disease. Access to transplant can be limited by geographic isolation from a center or the presence of comorbidities affecting transplant eligibility. Extracorporeal membrane oxygenation (ECMO)-supported patients are an uncommon but historically high-risk cohort of patients considered for lung transplant. We report the development of a service at our center to provide transport services to our hospital for patients unable to wean from ECMO support at their local institution for the purpose of evaluation for lung transplantation by our program. We developed a process for pre-transport consultation by the lung transplant physician team, standardized hand-off tools and equipment lists, and procedures for transitioning patients to transport ECMO machinery. Four patients have been transported to date including fixed wing (FW) and helicopter transports. All patients were successfully transported with either none or minor complications. Transport of ECMO-supported patients is a feasible method to increase access of patients with irreversible lung injured patients to evaluation for lung transplant. PMID:28275613

  11. Development of a new interfacility extracorporeal membrane oxygenation transport program for pediatric lung transplantation evaluation.

    PubMed

    Frazier, W Joshua; Shepherd, Edward G; Gee, Samantha W

    2017-02-01

    Pediatric lung transplantation is a life-saving intervention for children with irreversible end-stage lung disease. Access to transplant can be limited by geographic isolation from a center or the presence of comorbidities affecting transplant eligibility. Extracorporeal membrane oxygenation (ECMO)-supported patients are an uncommon but historically high-risk cohort of patients considered for lung transplant. We report the development of a service at our center to provide transport services to our hospital for patients unable to wean from ECMO support at their local institution for the purpose of evaluation for lung transplantation by our program. We developed a process for pre-transport consultation by the lung transplant physician team, standardized hand-off tools and equipment lists, and procedures for transitioning patients to transport ECMO machinery. Four patients have been transported to date including fixed wing (FW) and helicopter transports. All patients were successfully transported with either none or minor complications. Transport of ECMO-supported patients is a feasible method to increase access of patients with irreversible lung injured patients to evaluation for lung transplant.

  12. Remote cannulation and extracorporeal membrane oxygenation transport is safe in a newly established program.

    PubMed

    Grenda, David S; Moll, Vanessa; Kalin, Craig M; Blum, James M

    2017-02-01

    Extracorporeal membrane oxygenation (ECMO) has become an increasingly utilized modality for the support of patients with severe cardiac or pulmonary dysfunction. Unfortunately, the costs and expertise required to maintain a formal ECMO program preclude the vast majority of hospitals from employing such technology routinely. These barriers to implementation of an effective ECMO program highlight the importance of the safe transport of patients in need of extracorporeal support. While many centers with extensive expertise in the management of patients on extracorporeal support have demonstrated their ability to transport those same patients, the ability of new ECMO programs to provide such transportation remains poorly studied. We established an ECMO program at our institution and immediately provided equipment and personnel to transport patients in need of or receiving extracorporeal support to our institution. Overall, we found that 13 out of 28 patients transported to our institution on ECMO or for consideration of ECMO support during the first 15 months of the program survived to hospital discharge. During that period, four incidents associated with patient transport occurred but none were related to ECMO support or adversely affected patient outcome. These observations demonstrate that new ECMO programs can safely and reliably transport patients on or in need of extracorporeal support.

  13. [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.

  14. 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.

  15. Oxygen Depletion and Formation of Toxic Gases following Sea Transportation of Logs and Wood Chips

    PubMed Central

    Svedberg, Urban; Petrini, Caroline; Johanson, Gunnar

    2009-01-01

    Several recent accidents with fatal outcomes occurring during discharge of logs and wood chips from ships in Swedish ports indicate the need to better understand the atmospheric conditions in holds and connecting stairways. The principal aim of the present study was to assess the air levels of oxygen and toxic gases in confined spaces following sea transportation of logs and wood chips. The focus of the study was the conditions in the stairways, as this was the location of the reported accidents. Forty-one shipments of logs (pulpwood) and wood chips carried by 10 different ships were investigated before discharge in ports in northern Sweden. A full year was covered to accommodate variations due to seasonal temperature changes. The time from completion of loading to discharge was estimated to be 37–66 h (mean 46 h). Air samples were collected in the undisturbed air of altogether 76 stairways before the hatch covers were removed. The oxygen level was measured on-site by handheld direct-reading multi-gas monitors. On 16 of the shipments, air samples were additionally collected in Tedlar® bags for later analysis for carbon dioxide, carbon monoxide, and hydrocarbons by fourier transform infrared spectroscopy. The mean oxygen level was 10% (n = 76) but in 17% of the samples the oxygen level was 0%. The oxygen depletion was less pronounced during the cold season. The mean CO2 and CO levels were 7.5% (n = 26) and 46 p.p.m. (n = 28), respectively. More than 90% of the hydrocarbons were explained by monoterpenes, mainly α-pinene (mean 41 p.p.m., (n = 26). In conclusion, the measurements show that transport of logs and wood chips in confined spaces may result in rapid and severe oxygen depletion and CO2 formation. Thus, apparently harmless cargoes may create potentially life-threatening conditions. The oxygen depletion and CO2 formation are seemingly primarily caused by microbiological activity, in contrast to the oxidative processes with higher CO formation that

  16. Oxygen depletion and formation of toxic gases following sea transportation of logs and wood chips.

    PubMed

    Svedberg, Urban; Petrini, Caroline; Johanson, Gunnar

    2009-11-01

    Several recent accidents with fatal outcomes occurring during discharge of logs and wood chips from ships in Swedish ports indicate the need to better understand the atmospheric conditions in holds and connecting stairways. The principal aim of the present study was to assess the air levels of oxygen and toxic gases in confined spaces following sea transportation of logs and wood chips. The focus of the study was the conditions in the stairways, as this was the location of the reported accidents. Forty-one shipments of logs (pulpwood) and wood chips carried by 10 different ships were investigated before discharge in ports in northern Sweden. A full year was covered to accommodate variations due to seasonal temperature changes. The time from completion of loading to discharge was estimated to be 37-66 h (mean 46 h). Air samples were collected in the undisturbed air of altogether 76 stairways before the hatch covers were removed. The oxygen level was measured on-site by handheld direct-reading multi-gas monitors. On 16 of the shipments, air samples were additionally collected in Tedlar bags for later analysis for carbon dioxide, carbon monoxide, and hydrocarbons by fourier transform infrared spectroscopy. The mean oxygen level was 10% (n = 76) but in 17% of the samples the oxygen level was 0%. The oxygen depletion was less pronounced during the cold season. The mean CO2 and CO levels were 7.5% (n = 26) and 46 p.p.m. (n = 28), respectively. More than 90% of the hydrocarbons were explained by monoterpenes, mainly alpha-pinene (mean 41 p.p.m., (n = 26). In conclusion, the measurements show that transport of logs and wood chips in confined spaces may result in rapid and severe oxygen depletion and CO(2) formation. Thus, apparently harmless cargoes may create potentially life-threatening conditions. The oxygen depletion and CO(2) formation are seemingly primarily caused by microbiological activity, in contrast to the oxidative processes with higher CO formation that

  17. 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.

    2016-11-01

    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.

  18. Hazardous off-gassing of carbon monoxide and oxygen depletion during ocean transportation of wood pellets.

    PubMed

    Svedberg, Urban; Samuelsson, Jerker; Melin, Staffan

    2008-06-01

    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.

  19. Effects of myocardial infarction on the distribution and transport of nutrients and oxygen in porcine myocardium.

    PubMed

    Davis, Bryce H; Morimoto, Yoshihisa; Sample, Chris; Olbrich, Kevin; Leddy, Holly A; Guilak, Farshid; Taylor, Doris A

    2012-10-01

    One of the primary limitations of cell therapy for myocardial infarction is the low survival of transplanted cells, with a loss of up to 80% of cells within 3 days of delivery. The aims of this study were to investigate the distribution of nutrients and oxygen in infarcted myocardium and to quantify how macromolecular transport properties might affect cell survival. Transmural myocardial infarction was created by controlled cryoablation in pigs. At 30 days post-infarction, oxygen and metabolite levels were measured in the peripheral skeletal muscle, normal myocardium, the infarct border zone, and the infarct interior. The diffusion coefficients of fluorescein or FITC-labeled dextran (0.3-70 kD) were measured in these tissues using fluorescence recovery after photobleaching. The vascular density was measured via endogenous alkaline phosphatase staining. To examine the influence of these infarct conditions on cells therapeutically used in vivo, skeletal myoblast survival and differentiation were studied in vitro under the oxygen and glucose concentrations measured in the infarct tissue. Glucose and oxygen concentrations, along with vascular density were significantly reduced in infarct when compared to the uninjured myocardium and infarct border zone, although the degree of decrease differed. The diffusivity of molecules smaller than 40 kD was significantly higher in infarct center and border zone as compared to uninjured heart. Skeletal myoblast differentiation and survival were decreased stepwise from control to hypoxia, starvation, and ischemia conditions. Although oxygen, glucose, and vascular density were significantly reduced in infarcted myocardium, the rate of macromolecular diffusion was significantly increased, suggesting that diffusive transport may not be inhibited in infarct tissue, and thus the supply of nutrients to transplanted cells may be possible. in vitro studies mimicking infarct conditions suggest that increasing nutrients available to

  20. Finite Element Model of Oxygen Transport for the Design of Geometrically Complex Microfluidic Devices Used in Biological Studies

    PubMed Central

    Fraser, Graham M.; Goldman, Daniel; Ellis, Christopher G.

    2016-01-01

    Red blood cells play a crucial role in the local regulation of oxygen supply in the microcirculation through the oxygen dependent release of ATP. Since red blood cells serve as an oxygen sensor for the circulatory system, the dynamics of ATP release determine the effectiveness of red blood cells to relate the oxygen levels to the vessels. Previous work has focused on the feasibility of developing a microfluidic system to measure the dynamics of ATP release. The objective was to determine if a steep oxygen gradient could be developed in the channel to cause a rapid decrease in hemoglobin oxygen saturation in order to measure the corresponding levels of ATP released from the red blood cells. In the present study, oxygen transport simulations were used to optimize the geometric design parameters for a similar system which is easier to fabricate. The system is composed of a microfluidic device stacked on top of a large, gas impermeable flow channel with a hole to allow gas exchange. The microfluidic device is fabricated using soft lithography in polydimethyl-siloxane, an oxygen permeable material. Our objective is twofold: (1) optimize the parameters of our system and (2) develop a method to assess the oxygen distribution in complex 3D microfluidic device geometries. 3D simulations of oxygen transport were performed to simulate oxygen distribution throughout the device. The simulations demonstrate that microfluidic device geometry plays a critical role in molecule exchange, for instance, changing the orientation of the short wide microfluidic channel results in a 97.17% increase in oxygen exchange. Since microfluidic devices have become a more prominent tool in biological studies, understanding the transport of oxygen and other biological molecules in microfluidic devices is critical for maintaining a physiologically relevant environment. We have also demonstrated a method to assess oxygen levels in geometrically complex microfluidic devices. PMID:27829071

  1. Large-eddy simulation of oxygen transport and depletion in waterbodies

    NASA Astrophysics Data System (ADS)

    Scalo, Carlo; Piomelli, Ugo; Boegman, Leon

    2010-11-01

    Dissolved oxygen (DO) in water plays an important role in lake and marine ecosystems. Agricultural runoff may spur excessive plant growth on the water surface; when the plants die they sink to the bottom of the water bodies and decompose, consuming oxygen. Significant environmental (and economic) damage may result from the loss of aquatic life caused by the oxygen depletion. The study of DO transport and depletion dynamics in water bodies has, therefore, become increasingly important. We study this phenomenon by large-eddy simulations performed at laboratory scale. The equations governing the transport of momentum and of a scalar (the DO) in the fluid are coupled to a biochemical model for DO depletion in the permeable sediment bed [Higashino et al., Water Res. (38) 1, 2004)], and to an equation for the fluid transpiration in the porous medium. The simulations are in good agreement with previous calculations and experiments. We show that the results are sensitive to the biochemical and fluid dynamical properties of the sediment, which are very difficult to determine experimentally.

  2. The oxygen transport system of red blood cells during diabetic ketoacidosis and recovery.

    PubMed

    Ditzel, J; Standl, E

    1975-08-01

    Daily evaluations of 8 newly detected ketoacidotic diabetics showed the Bohr-effect of haemoglobin to be decreased by 50% while erythrocyte 2,3-DPG was decreased below 10 mumoles/g Hb. 2,3-DPG correlated strongly with pH during acidosis and with plasma inorganic phosphate (Pi) subsequently to the first insulin administration. Oxygen affinity of haemoglobin, measured as P50 act pH, was unchanged in ketoacidosis compared to the time, however, P50 act pH fell striking (p less than 0.001) and remained decreased up to 7 days depending upon the resynthesis of 2,3-DPG in relation to Pi. The Hill-coefeficient in reflecting the slope of the oxygen dissociation curve was diminished in ketoacidosis (p less than 0.005), and decreased further after pH-normalization (p less than 0.005). There was a close association of n with 2,3-DPG (p less than 0.001) and additionally with Pi at 2,3-DPG-levels below 10 mumoles/g Hb. Based on these findings a decreased erythrocyte oxygen release of one fifth during acidosis and more than one third after pH-correction can be hypothesised. In view of the intimate relation of Pi to the oxygen transport system it is suggesed that treatment of ketoacidosis should include Pi-sugstitution.

  3. Calculations of oxygen transport by red blood cells and hemoglobin solutions in capillaries.

    PubMed

    Vadapalli, Arjun; Goldman, Daniel; Popel, Aleksander S

    2002-05-01

    A theoretical model is developed to investigate the influence of hemoglobin-based oxygen carriers (HBOCs) on oxygen transport in capillary-size vessels. A discrete cell model is presented with red blood cells (RBCs) represented in their realistic parachute shape flowing in a single file through a capillary. The model includes the free and Hb-facilitated transport of O2 and Hb-O2 kinetics in the RBC and plasma, diffusion of free O2 in the suspending phase, capillary wall, interstitium and tissue. A constant tissue consumption rate is specified that drives the simultaneous release of O2 from RBC and plasma as the cells traverse the capillary. The model mainly focuses on low capillary hematocrits and studies the effect of free hemoglobin affinity, cooperativity and concentration. The results are expressed in the form of cell and capillary mass transfer coefficients, or inverse transport resistances, that relate the spatially averaged flux of O2 coming out of the RBC and capillary to a driving force for O2 diffusion. The results show that HBOCs at a concentration of 7 g/dl reduce the intracapillary transport resistance by as much as 60% when capillary hematocrit is 0.2. HBOCs with high O2 affinity unload most O2 at the venular end, while those with low affinity supply O2 at the arteriolar end. A higher cooperativity did not favor O2 delivery due to the large variation in the mass transfer coefficient values during O2 unloading. The mass transfer coefficients obtained will be used in simulations of O2 transport in complex capillary networks.

  4. Conditions for economic benefit by using lunar oxygen for earth-moon transportation systems

    NASA Astrophysics Data System (ADS)

    Reichert, M.; Lingner, S.; Seboldt, W.

    1992-08-01

    The paper considers the use of MOONLOX, lunar oxygen, for an earth-moon transportation system consisting of an aeroassisted orbital transfer vehicle and a lunar bus for lunar descent/ascent. Conditions for economic benefit are discussed, and the processing concept of a lunar oxygen plant based on fluorination is presented. It is contended that the necessary supply rate from earth from MOONLOX production must be smaller than a critical number for each considered MOONLOX-utilization scenario to yield a saving of mass launched into LEO (compared to a 'reference scenario' with an earth-derived propellant. The MOONLOX production costs must fall below the calculated upper limits (parametrically dependent of launch costs). It is inferred that for the MOONLOX production process by fluorination, fluorine recycling is highly desirable.

  5. 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.

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

    DOE PAGES

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

    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

  7. 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

  8. Different working mechanisms for a graphene resistive memory based on oxygen-ion transport

    NASA Astrophysics Data System (ADS)

    Lee, Seunghyun

    2017-01-01

    A graphene sheet was used as one of the electrodes of a HfO2 metal-oxide-based resistive random access memory. We find dramatic differences in the device characteristics as voltages with opposite polarities are used to form the resistive memory devices. Using experimental measurements of the switching characteristics and the corresponding low and high resistance state, we compare the two different operating modes of a graphene-electrode-based resistive memory. Using a Raman raster scanning map, we verify that the transport direction of oxygen ions contributes to such dramatic differences in the device's switching characteristics.

  9. [Oxygen-transporting function of the blood circulation system in sevoflurane anesthesia during myocardial revascularization under extracorporeal circulation].

    PubMed

    Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V

    2009-01-01

    The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.

  10. Role of Membrane Lipids in the Regulation of Erythrocytic Oxygen-Transport Function in Cardiovascular Diseases

    PubMed Central

    Revin, Victor V.; Revina, Elvira S.; Martynova, Maria I.; Seikina, Angelina I.; Revina, Nadezhda V.; Imarova, Oksana G.; Solomadin, Ilia N.; Tychkov, Alexander Yu.; Zhelev, Nikolai

    2016-01-01

    The composition and condition of membrane lipids, the morphology of erythrocytes, and hemoglobin distribution were explored with the help of laser interference microscopy (LIM) and Raman spectroscopy. It is shown that patients with cardiovascular diseases (CVD) have significant changes in the composition of their phospholipids and the fatty acids of membrane lipids. Furthermore, the microviscosity of the membranes and morphology of the erythrocytes are altered causing disordered oxygen transport by hemoglobin. Basic therapy carried out with the use of antiaggregants, statins, antianginals, beta-blockers, and calcium antagonists does not help to recover the morphofunctional properties of erythrocytes. Based on the results the authors assume that, for the relief of the ischemic crisis and further therapeutic treatment, it is necessary to include, in addition to cardiovascular disease medicines, medication that increases the ability of erythrocytes' hemoglobin to transport oxygen to the tissues. We assume that the use of LIM and Raman spectroscopy is advisable for early diagnosis of changes in the structure and functional state of erythrocytes when cardiovascular diseases develop. PMID:27872848

  11. Oxygen transport membrane reactor based method and system for generating electric power

    DOEpatents

    Kelly, Sean M.; Chakravarti, Shrikar; Li, Juan

    2017-02-07

    A carbon capture enabled system and method for generating electric power and/or fuel from methane containing sources using oxygen transport membranes by first converting the methane containing feed gas into a high pressure synthesis gas. Then, in one configuration the synthesis gas is combusted in oxy-combustion mode in oxygen transport membranes based boiler reactor operating at a pressure at least twice that of ambient pressure and the heat generated heats steam in thermally coupled steam generation tubes within the boiler reactor; the steam is expanded in steam turbine to generate power; and the carbon dioxide rich effluent leaving the boiler reactor is processed to isolate carbon. In another configuration the synthesis gas is further treated in a gas conditioning system configured for carbon capture in a pre-combustion mode using water gas shift reactors and acid gas removal units to produce hydrogen or hydrogen-rich fuel gas that fuels an integrated gas turbine and steam turbine system to generate power. The disclosed method and system can also be adapted to integrate with coal gasification systems to produce power from both coal and methane containing sources with greater than 90% carbon isolation.

  12. 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.

  13. Effects of autoregulation and CO2 reactivity on cerebral oxygen transport.

    PubMed

    Payne, S J; Selb, J; Boas, D A

    2009-11-01

    Both autoregulation and CO(2) reactivity are known to have significant effects on cerebral blood flow and thus on the transport of oxygen through the vasculature. In this paper, a previous model of the autoregulation of blood flow in the cerebral vasculature is expanded to include the dynamic behavior of oxygen transport through binding with hemoglobin. The model is used to predict the transfer functions for both oxyhemoglobin and deoxyhemoglobin in response to fluctuations in arterial blood pressure and arterial CO(2) concentration. It is shown that only six additional nondimensional groups are required in addition to the five that were previously found to characterize the cerebral blood flow response. A resonant frequency in the pressure-oxyhemoglobin transfer function is found to occur in the region of 0.1 Hz, which is a frequency of considerable physiological interest. The model predictions are compared with results from the published literature of phase angle at this frequency, showing that the effects of changes in breathing rate can significantly alter the inferred phase dynamics between blood pressure and hemoglobin. The question of whether dynamic cerebral autoregulation is affected under conditions of stenosis or stroke is then examined.

  14. 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.

  15. 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.

  16. 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.

  17. [Positive results with haematology webcasting for junior doctors].

    PubMed

    Raaschou-Jensen, Klas; Thomsen, Rasmus Heje; Gang, Anne Ortved; Do, Thrung; Aagaard, Thomas; Niemann, Carsten; Bjerrum, Ole Weis

    2016-01-11

    Webcasting is an educational activity where the teacher and the participants are separated in space and time when using modern information technology. It is widely used for all learning levels and in all educational forms of haematology training in Europe. A working group in the Education Council of internal medicine, haematology in the eastern part of Denmark initiated a project with webcasting from local haematological departments. The aim of the education project was to contribute to spreading knowledge and support the training of specialist in haematology. Our experience is hereby reported.

  18. 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

  19. The liquid-ordered phase in sphingomyelincholesterol membranes as detected by the discrimination by oxygen transport (DOT) method.

    PubMed

    Wisniewska, Anna; Subczynski, Witold K

    2008-01-01

    Membranes made from binary mixtures of egg sphingomyelin (ESM) and cholesterol were investigated using conventional and saturation-recovery EPR observations of the 5-doxylstearic acid spin label (5-SASL). The effects of cholesterol on membrane order and the oxygen transport parameter (bimolecular collision rate of molecular oxygen with the nitroxide spin label) were monitored at the depth of the fifth carbon in fluid- and gel-phase ESM membranes. The saturation-recovery EPR discrimination by oxygen transport (DOT) method allowed the discrimination of the liquid-ordered (l(o)), liquid-disordered (l(d)), and solid-ordered (s(o)) phases because the bimolecular collision rates of the molecular oxygen with the nitroxide spin label differ in these phases. Additionally, oxygen collision rates (the oxygen transport parameter) were obtained in coexisting phases without the need for their separation, which provides information about the internal dynamics of each phase. The addition of cholesterol causes a dramatic decrease in the oxygen transport parameter around the nitroxide moiety of 5-SASL in the l(o) phase, which at 50 mol% cholesterol becomes approximately 5 times smaller than in the pure ESM membrane in the l(d) phase, and approximately 2 times smaller than in the pure ESM membrane in the s(o) phase. The overall change in the oxygen transport parameter is as large as approximately 20-fold. Conventional EPR spectra show that 5-SASL is maximally immobilized at the phase boundary between regions with coexisting l(d) and l(o) phases or s(o) and l(o) phases and the region with a single l(o) phase. The obtained results allowed for the construction of a phase diagram for the ESM-cholesterol membrane.

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

    DOE PAGES

    Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui; ...

    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

  1. 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.

  2. 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.

  3. 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.

  4. Cutaneous aspergillosis in patients with haematological malignancies.

    PubMed

    D'Antonio, D; Pagano, L; Girmenia, C; Parruti, G; Mele, L; Candoni, A; Ricci, P; Martino, P

    2000-05-01

    The aim of the present study was to evaluate skin infections caused by Aspergillus in patients with haematological malignancies. Fifteen cases of cutaneous aspergillosis are reported, 12 of which occurred among 4448 consecutive patients with acute leukaemia. Cutaneous involvement occurred in 4% of patients with documented Aspergillus infection. Primary cutaneous aspergillosis was diagnosed in five cases. Infection was fatal in 11 of 15 cases; the absence of additional sites of infection other than cutis at presentation appeared to be the only factor related to a favourable outcome.

  5. Multimodality imaging of osseous involvement In haematological malignancies

    PubMed Central

    Krajewski, Katherine M; Jagannathan, Jyothi P; Shinagare, Atul B; Braschi-Amirfarzan, Marta; Tirumani, Sree H; Ramaiya, Nikhil H

    2016-01-01

    The purpose of this article is to provide a comprehensive review of the imaging features of osseous involvement in haematological malignancies. Osseous involvement can be seen in various haematological malignancies including lymphomas, plasma cell neoplasms, leukaemias and myeloproliferative neoplasms. Imaging plays a crucial role in initial diagnosis, staging and in the assessment of treatment response in these patients. PMID:26781757

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Effects of Reactive Oxygen Species on Tubular Transport along the Nephron.

    PubMed

    Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

    2017-03-23

    Reactive oxygen species (ROS) are oxygen-containing molecules naturally occurring in both inorganic and biological chemical systems. Due to their high reactivity and potentially damaging effects to biomolecules, cells express a battery of enzymes to rapidly metabolize them to innocuous intermediaries. Initially, ROS were considered by biologists as dangerous byproducts of respiration capable of causing oxidative stress, a condition in which overproduction of ROS leads to a reduction in protective molecules and enzymes and consequent damage to lipids, proteins, and DNA. In fact, ROS are used by immune systems to kill virus and bacteria, causing inflammation and local tissue damage. Today, we know that the functions of ROS are not so limited, and that they also act as signaling molecules mediating processes as diverse as gene expression, mechanosensation, and epithelial transport. In the kidney, ROS such as nitric oxide (NO), superoxide (O₂(-)), and their derivative molecules hydrogen peroxide (H₂O₂) and peroxynitrite (ONO₂(-)) regulate solute and water reabsorption, which is vital to maintain electrolyte homeostasis and extracellular fluid volume. This article reviews the effects of NO, O₂(-), ONO₂(-), and H₂O₂ on water and electrolyte reabsorption in proximal tubules, thick ascending limbs, and collecting ducts, and the effects of NO and O₂(-) in the macula densa on tubuloglomerular feedback.

  11. Biogenic oxygen from Earth transported to the Moon by a wind of magnetospheric ions

    NASA Astrophysics Data System (ADS)

    Terada, Kentaro; Yokota, Shoichiro; Saito, Yoshifumi; Kitamura, Naritoshi; Asamura, Kazushi; Nishino, Masaki N.

    2017-01-01

    For five days of each lunar orbit, the Moon is shielded from solar wind bombardment by the Earth's magnetosphere, which is filled with terrestrial ions. Although the possibility of the presence of terrestrial nitrogen and noble gases in lunar soil has been discussed based on their isotopic composition 1 , complicated oxygen isotope fractionation in lunar metal 2,3 (particularly the provenance of a 16O-poor component) re­mains an enigma 4,5 . Here, we report observations from the Japanese spacecraft Kaguya of significant numbers of 1-10 keV O+ ions, seen only when the Moon was in the Earth's plasma sheet. Considering the penetration depth into metal of O+ ions with such energy, and the 16O-poor mass-independent fractionation of the Earth's upper atmosphere 6 , we conclude that biogenic terrestrial oxygen has been transported to the Moon by the Earth wind (at least 2.6 × 104 ions cm‑2 s‑1) and implanted into the surface of the lunar regolith, at around tens of nanometres in depth 3,4 . We suggest the possibility that the Earth's atmosphere of billions of years ago may be preserved on the present-day lunar surface.

  12. 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.

  13. A survey of Australian haematology reference intervals.

    PubMed

    Sinclair, Leanne; Hall, Sara; Badrick, Tony

    2014-10-01

    This study was designed to create a snapshot of Australian haematology reference intervals (RIs) in use, in particular red cell parameters. We present an analysis of survey results conducted across Australian laboratories between November 2012 and January 2013.All Australian laboratories enrolled in the Royal College of Pathologists of Australasia Quality Assurance Program (RCPA QAP) were invited to participate in the December 2012 Survey Monkey survey, with a response from 85 laboratories (17%) received. The scope included laboratory demographics (location, size/throughput, and network), RIs in use for the full blood count and selected derived parameters, their frequency of revision, source and statistical approach for derivation. Further questions related to uncertainty of measurement, pregnancy values, paediatric/adult cut-off, haematology profiles reported and the use of extended parameters.There is more consistency with some upper and lower limits than others, and wide ranges for reported uncertainty of measurement (UM). There is no apparent consistency with RIs used for particular instruments and technologies. When laboratories change their RIs, most obtain them from a text book, paper or another laboratory and have difficulty in determining the source. If they do determine their own, most don't have a standard operating procedure and calculations are not consistent in terms of sample size and statistical methods used.We have presented evidence of the wide variations in RIs used in Australian laboratories and that arguably these do not differ significantly from each other. The paediatric age cut-off requires standardisation.

  14. 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.

  15. Proliferative kidney disease in rainbow trout (Oncorhynchus mykiss) under intensive breeding conditions: Pathogenesis and haematological and immune parameters.

    PubMed

    Palikova, Miroslava; Papezikova, Ivana; Markova, Zdenka; Navratil, Stanislav; Mares, Jan; Mares, Lukas; Vojtek, Libor; Hyrsl, Pavel; Jelinkova, Eva; Schmidt-Posthaus, Heike

    2017-03-06

    Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematological findings and immune functions. Diseased and reference fish were sampled monthly and time course of natural infection was followed up from the onset of clinical signs (September 2014) to full recovery (January 2015). PKD- associated cumulative mortality was 30% with a peak value in October, while immunohistochemical testing indicated a continuous significant decrease in T. bryosalmonae numbers from September to December; with no parasites detected in January. During peak clinical infection, a significant decrease in red blood cell counts, haematocrit values, haemoglobin concentration, along with a reduction in lymphocytes and a significant phagocyte elevation corresponding with an increase in phagocyte oxidative burst were measured in comparison to control animals. Complement activity and total immunoglobulin plasma concentrations were also elevated, though only during the initial monitoring period (September). Individuals surviving PKD, recovered and were able to fully regenerate both renal structure and haematopoietic parameters to normal levels. Changes in the red blood cell parameters indicate anaemia and a decreased oxygen transportation capacity during the clinical disease phase. Together with an increased oxygen demand at higher temperatures and decreased oxygen solubility this could lead to decompensation and elevated mortality. The stimulation of immune parameters, and especially oxidative phagocytic burst, is likely to have had a strong effect on both, regeneration and elimination of the pathogenic agent.

  16. The importance of conceptual models in the reactive transport simulation of oxygen ingress in sparsely fractured crystalline rock.

    PubMed

    Macquarrie, K T B; Mayer, K U; Jin, B; Spiessl, S M

    2010-03-01

    Redox evolution in sparsely fractured crystalline rocks is a key, and largely unresolved, issue when assessing the geochemical suitability of deep geological repositories for nuclear waste. Redox zonation created by the influx of oxygenated waters has previously been simulated using reactive transport models that have incorporated a variety of processes, resulting in predictions for the depth of oxygen penetration that may vary greatly. An assessment and direct comparison of the various underlying conceptual models are therefore needed. In this work a reactive transport model that considers multiple processes in an integrated manner is used to investigate the ingress of oxygen for both single fracture and fracture zone scenarios. It is shown that the depth of dissolved oxygen migration is greatly influenced by the a priori assumptions that are made in the conceptual models. For example, the ability of oxygen to access and react with minerals in the rock matrix may be of paramount importance for single fracture conceptual models. For fracture zone systems, the abundance and reactivity of minerals within the fractures and thin matrix slabs between the fractures appear to provide key controls on O(2) attenuation. The findings point to the need for improved understanding of the coupling between the key transport-reaction feedbacks to determine which conceptual models are most suitable and to provide guidance for which parameters should be targeted in field and laboratory investigations.

  17. Peromyscus leucopus mice: a potential animal model for haematological studies.

    PubMed

    Sun, Yu; Desierto, Marie J; Ueda, Yasutaka; Kajigaya, Sachiko; Chen, Jichun; Young, Neal S

    2014-10-01

    Peromyscus leucopus mice share physical similarities with laboratory mice Mus musculus (MM) but have higher agility and longer lifespan. We compared domesticated P. leucopus linville (PLL) and M. musculus C57BL/6 (MMB6) mice for cellular composition of peripheral blood (PB), bone marrow (BM) and spleen. PLL mice had significantly fewer platelets and significantly more monocytes in the blood, and notably fewer megakaryocytes in the BM. Spleens of PLL mice were significantly smaller, with 50% fewer cells and reduced 'red pulp'. There was no obvious haematological change in PLL mice between 2-8 and 16-26 months of age, except for a significant increase in blood monocytes. Cellular reactive oxygen species (ROS) content showed no change with age but differed significantly between different cell types. Treating two to eight month-old PLL mice with antioxidant N-acetylcysteine in drinking water for three months did not affect cellular ROS content, but increased blood leucocytes especially the concentration of monocytes. The low platelets, low megakaryocytes, high monocytes and low splenic erythropoiesis in PLL mice resemble human measurements better than the values seen in MMB6.

  18. Peromyscus leucopus mice: a potential animal model for haematological studies

    PubMed Central

    Sun, Yu; Desierto, Marie J; Ueda, Yasutaka; Kajigaya, Sachiko; Chen, Jichun; Young, Neal S

    2014-01-01

    Peromyscus leucopus mice share physical similarities with laboratory mice Mus musculus (MM) but have higher agility and longer lifespan. We compared domesticated P. leucopus linville (PLL) and M. musculus C57BL/6 (MMB6) mice for cellular composition of peripheral blood (PB), bone marrow (BM) and spleen. PLL mice had significantly fewer platelets and significantly more monocytes in the blood, and notably fewer megakaryocytes in the BM. Spleens of PLL mice were significantly smaller, with 50% fewer cells and reduced ‘red pulp’. There was no obvious haematological change in PLL mice between 2–8 and 16–26 months of age, except for a significant increase in blood monocytes. Cellular reactive oxygen species (ROS) content showed no change with age but differed significantly between different cell types. Treating two to eight month-old PLL mice with antioxidant N-acetylcysteine in drinking water for three months did not affect cellular ROS content, but increased blood leucocytes especially the concentration of monocytes. The low platelets, low megakaryocytes, high monocytes and low splenic erythropoiesis in PLL mice resemble human measurements better than the values seen in MMB6. PMID:25116892

  19. Haematological analysis conducted at the departure of the Tour de France 2001.

    PubMed

    Robinson, N; Schattenberg, L; Zorzoli, M; Mangin, P; Saugy, M

    2005-04-01

    Since the introduction of blood analysis performed before major cycling events in 1997, there have been discussions concerning the quality of the results. The aim of our study therefore was to measure blood samples and compare the results obtained on the field with those obtained in the laboratory. For this it was necessary to have blood samples analysed with different instruments to determine the exactness of the results and evaluate the performances of these instruments in order to validate the haematological testing used to reveal athletes abusing recombinant erythropoietin. We report on the haematological analysis of 177 professional cyclists who took part in the Tour de France 2001. All the blood samples were withdrawn in the morning between 7 and 9 am in Dunkerque (France) and were analysed immediately with a transportable analyser. Then the samples were flown to Lausanne (Switzerland) and were reanalysed in two independent ISO 17 025 accredited laboratories with three different analysers. The results confirmed that the most effective haematological follow-up should be performed under standardized pre-analytical conditions and with identical analysers of the same manufacturer to avoid too many variations notably on the haematocrit level and the reticulocyte count. Furthermore, this study suggests that analyses performed on the site are good and could enable the federations to perform a urinary test to detect rhEPO abuse right after the blood analysis. This time saving is essential to fight efficiently recombinant erythropoietin doping, because the half life of the hormone is very short.

  20. Severe malaria in immigrant haematological patient

    PubMed Central

    Vázquez-Sánchez, R.; Martínez-Núñez, M.E.; Molina-García, T.

    2015-01-01

    Severe malaria is a life-threatening condition caused by Plasmodium falciparum. Rupture of red blood cells when merozoites release to the bloodstream is responsible for the clinical manifestations, febrile fever reaching 39 °C, and other unspecific symptoms. P. falciparum is considered as the worst form of malaria. Moreover, this species has cytoadherence to red blood cells. This can lead to an organic dysfunction. People coming from hyper endemic areas have developed a partial immunity, but immunodepressed people are a group with a greater risk. Due to the high mortality rate associated to this disease, early diagnosis and a prompt treatment implementation are essential. However, the missed or delayed diagnosis is one of the major reasons of reaching a severe malaria disease. This case reflects the complexity of the diagnosis in an immigrant and immunodepressed patient with a haematological neoplasm with a severe infection by P. falciparum due to the unspecified symptoms and the overlapping of the same. PMID:26793463

  1. Normal State Transport in Superconducting Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) and Semiconducting Praseodymium BARIUM(2) COPPER(3) OXYGEN(7-DELTA)

    NASA Astrophysics Data System (ADS)

    Browning, Valerie Michelle

    1995-01-01

    The discovery, in 1986, of materials with superconducting transition temperatures well above 77 K has generated a renewed interest in potential applications for superconductors. Unfortunately, the widespread use of high temperature superconductors (HTS) has not been realized due to their poor performance in terms of electrical and physical properties. Although the mechanism of high temperature superconductivity remains a mystery, it is hoped that an understanding of the HTS will result in the ability to engineer better quality materials. The normal state of the HTS exhibits several features which are considered unusual. Among these features are a linear temperature dependence of the resistivity and a temperature dependent Hall effect. It is believed that knowledge of the normal state transport properties of the HTS is crucial to understanding superconductivity in these materials. In an effort to better understand the normal state of the these materials, the transport properties of single crystal samples of two members of the superconducting RBa_2Cu_3O _{7-delta} ("123") family were studied (R = yttrium and many of the rare earth elements). Resistivity, Hall effect, and magnetoresistance measurements were performed on a detwinned single crystal sample of YBa_2Cu_3 _{7-delta} (Y 123). Measurements were repeated after various oxygen anneals to study the effects of oxygen inhomogeneities on the sample's transport properties. These results indicate that oxygen inhomogeneities strongly influence the transport properties of this system. A model is presented which takes into account oxygen defects in calculating the resistivity and Hall coefficient. Of the rare earth elements that will form the 123 structure, only PrBa_2Cu _3O_{7-delta} (Pr 123) does not superconduct. Pr 123 exhibits a non-metallic temperature dependent resistivity as opposed to the metallic resistivity exhibited by the superconducting 123 family members. Magnetotransport and magnetization measurements

  2. Reactive transport modeling of dissolved oxygen migration and consumption in a sedimentary basins affected by a deglaciation event

    NASA Astrophysics Data System (ADS)

    Bea, S. A.; Mayer, K. U.; MacQuarrie, K. T.

    2012-12-01

    In intracratonic sedimentary basins, geochemical conditions are currently reducing at depth. Deep groundwater flow systems are driven primarily by salinity differences, topographic gradients and recharge derived from precipitation; these systems are also influenced by the hydrostratigraphy of the basin. However, during periods of glacial melt water production (i.e., deglaciation events), the melting of ice sheets may alter the patterns of freshwater infiltration, potentially resulting in enhanced recharge of glacial melt water containing relatively high concentrations of dissolved oxygen. Reactive transport modeling can be used to understand the evolution of geochemical conditions and redox-buffering capacity of these formations. Dissolved oxygen will interact with reduced mineral phases that are present in the sedimentary units (e.g., chlorite) or with solid organic matter causing oxygen consumption. Processes included in the model are density-driven flow and transport, vertical mechanical deformation, as well as chemical reactions (aqueous complexation, mineral dissolution and precipitation including evaporites, sulfates and carbonates, cation-exchange, redox processes involving the decomposition of organic matter, dissolution of Fe-bearing minerals, biotite and chlorite, and the oxidation of ferrous iron and sulfide). Transient boundary conditions are imposed in the upper part of the model to mimic ice sheet advance and retreat. Simulation results indicate that the presence of dense brines at depth results in low groundwater velocities during glacial meltwater infiltration, restricting the ingress of oxygenated waters in the basin. In addition, due to the abundance of reduced mineral phases and solid organic matter in these formations, geochemical processes causing oxygen consumption are restricted to shallow aquifers, further limiting the ingress of oxygenated waters to the first 100 m in the main aquifers (i.e., sandstones) and 50 m in the carbonates aquifers

  3. The Mechanisms of Oxygen Reduction in the Terminal Reducing Segment of the Chloroplast Photosynthetic Electron Transport Chain.

    PubMed

    Kozuleva, Marina A; Ivanov, Boris N

    2016-07-01

    The review is dedicated to ascertainment of the roles of the electron transfer cofactors of the pigment-protein complex of PSI, ferredoxin (Fd) and ferredoxin-NADP reductase in oxygen reduction in the photosynthetic electron transport chain (PETC) in the light. The data regarding oxygen reduction in other segments of the PETC are briefly analyzed, and it is concluded that their participation in the overall process in the PETC under unstressful conditions should be insignificant. Data concerning the contribution of Fd to the oxygen reduction in the PETC are examined. A set of collateral evidence as well as results of direct measurements of the involvement of Fd in this process in the presence of isolated thylakoids led to the inference that this contribution in vivo is negligible. The increase in oxygen reduction rate in the isolated thylakoids in the presence of either Fd or Fd plus NADP(+) under increasing light intensity was attributed to the increase in oxygen reduction executed by the membrane-bound oxygen reductants. Data are presented which imply that a main reductant of the O2 molecule in the terminal reducing segment of the PETC is the electron transfer cofactor of PSI, phylloquinone. The physiological significance of characteristic properties of oxygen reductants in this segment of the PETC is discussed.

  4. The effect of sustained compression on oxygen metabolic transport in the intervertebral disc decreases with degenerative changes.

    PubMed

    Malandrino, Andrea; Noailly, Jérôme; Lacroix, Damien

    2011-08-01

    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

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... 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 the lavatory. This AD was prompted by reports that the current design of these oxygen generators presents...

  6. Pulsatile flow and oxygen transport past cylindrical fiber arrays for an artificial lung: computational and experimental studies.

    PubMed

    Zierenberg, Jennifer R; Fujioka, Hideki; Cook, Keith E; Grotberg, James B

    2008-06-01

    The influence of time-dependent flows on oxygen transport from hollow fibers was computationally and experimentally investigated. The fluid average pressure drop, a measure of resistance, and the work required by the heart to drive fluid past the hollow fibers were also computationally explored. This study has particular relevance to the development of an artificial lung, which is perfused by blood leaving the right ventricle and in some cases passing through a compliance chamber before entering the device. Computational studies modeled the fiber bundle using cylindrical fiber arrays arranged in in-line and staggered rectangular configurations. The flow leaving the compliance chamber was modeled as dampened pulsatile and consisted of a sinusoidal perturbation superimposed on a steady flow. The right ventricular flow was modeled to depict the period of rapid flow acceleration and then deceleration during systole followed by zero flow during diastole. Experimental studies examined oxygen transfer across a fiber bundle with either steady, dampened pulsatile, or right ventricular flow. It was observed that the dampened pulsatile flow yielded similar oxygen transport efficiency to the steady flow, while the right ventricular flow resulted in smaller oxygen transport efficiency, with the decrease increasing with Re. Both computations and experiments yielded qualitatively similar results. In the computational modeling, the average pressure drop was similar for steady and dampened pulsatile flows and larger for right ventricular flow while the pump work required of the heart was greatest for right ventricular flow followed by dampened pulsatile flow and then steady flow. In conclusion, dampening the artificial lung inlet flow would be expected to maximize oxygen transport, minimize work, and thus improve performance.

  7. Trial of Haploidentical Stem Cell Transplantation for Haematological Cancers

    ClinicalTrials.gov

    2016-11-11

    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

  8. Genetic reference materials and their application to haematology.

    PubMed

    Hawkins, J R; Hawkins, M; Boyle, J; Gray, E; Matejtschuk, P; Metcalfe, P

    2010-07-01

    Genetic investigations are becoming increasingly useful and widespread in many areas of human health. However, there is a worldwide lack of certified reference materials for use in genetic testing, meaning that tests are being run without well validated controls and new assays are more difficult to develop and validate. We have responded to this challenge by starting a programme of developing genetic reference materials (GRMs) for international accreditation and worldwide distribution. Our approach has been to make materials for disorders where testing is commonplace and genotyping errors have been demonstrated. To ensure a continuing supply of DNA, cell lines are established from consenting, phenotypically well-characterised patients and are then grown up in bulk for genomic DNA extraction to yield up to 100 milligrams of DNA. In most cases the DNA is then formulated, freeze-dried and sealed in glass ampoules to ensure greater stability over time and obviate the need for chilled transportation. In this paper we explore the options and routes available to the production of DNA reference materials and describe the establishment of the first internationally recognised reference materials for human genomic DNA, with particular reference to some genetic tests carried out frequently within haematological and cardiovascular laboratories.

  9. 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.

  10. 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

  11. Myoglobin translational diffusion in rat myocardium and its implication on intracellular oxygen transport

    PubMed Central

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

    2007-01-01

    Current theory of respiratory control invokes a role of myoglobin (Mb)-facilitated O2 diffusion in regulating the intracellular O2 flux, provided Mb diffusion can compete effectively with free O2 diffusion. Pulsed-field gradient NMR methods have now followed gradient-dependent changes in the distinct 1H NMR γ CH3 Val E11 signal of MbO2 in perfused rat myocardium to obtain the endogenous Mb translational diffusion coefficient (DMb) of 4.24 × 10−7 cm2 s−1 at 22°C. The DMb matches precisely the value predicted by in vivo NMR rotational diffusion measurements of Mb and shows no orientation preference. Given values in the literature for the Krogh's free O2 diffusion coefficient (K0), myocardial Mb concentration and a partial pressure of O2 that half saturates Mb (P50), the analysis yields an equipoise diffusion PO2 of 1.77 mmHg, where Mb and free O2 contribute equally to the O2 flux. In the myocardium, Mb-facilitated O2 diffusion contributes increasingly more than free O2 diffusion when the PO2 falls below 1.77 mmHg. In skeletal muscle, the PO2 must fall below 5.72 mmHg. Altering the Mb P50 induces modest change. Mb-facilitated diffusion has a higher poise in skeletal muscle than in myocardium. Because the basal PO2 hovers around 10 mmHg, Mb does not have a predominant role in facilitating O2 transport in myocardium but contributes significantly only when cellular oxygen falls below the equipoise diffusion PO2. PMID:17038435

  12. 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.

  13. Indirect Liquefaction of Biomass to Transportation Fuels Via Mixed Oxygenated Intermediates

    SciTech Connect

    Tan, Eric C.D.

    2016-11-14

    This paper presents a comparative techno-economic analysis of four emerging conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The processing steps include: biomass-to-syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation.

  14. Sources and transport of sediment, nutrients, and oxygen-demanding substances in the Minnesota River basin, 1989-92

    USGS Publications Warehouse

    Payne, G.A.

    1994-01-01

    The Minnesota River, 10 major tributaries, and 21 springs were sampled to determine the sources and transport of sediment, nutrients, and oxygen- demanding substances. The study was part of a four-year assessment of non-point source pollution in the Minnesota River Basin. Runoff from tributary watersheds was identified as the primary source of suspended sediment and nutrients in the Minnesota River mainstem. Suspended-sediment, phosphorus, and nitrate concentrations were elevated in all major tributaries during runoff, but tributaries in the south-central and eastern part of the basin produce the highest annual loading to the mainstem because of higher annual precipitation and runoff in that part of the basin. Particle-size analyses showed that most of the suspended sediment in transport consisted of silt- and clay-size material. Phosphorus enrichment was indicated throughout the mainstem by total phosphorus concentrations that ranged from 0.04 to 0.48 mg/L with a median value of 0.22 mg/L, and an interquartile range of 0.15 to 0.29 mg/L. Nitrate concentrations periodically exceeded drinking water standards in tributaries draining the south-central and eastern part of the basin. Oxygen demand was most elevated during periods of summer low flow. Correlations between levels of biochemical oxygen demand and levels of algal productivity suggest that algal biomass comprises much of the oxygen-demanding material in the mainstem. Transport of sediment, nutrients, and organic carbon within the mainstem was found to be conservative, with nearly all tributary inputs being transported downstream. Uptake and utilization of nitrate and orthophosphorus was indicated during low flow, but at normal and high flow, inputs of these constituents greatly exceeded biological utilization.

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

    PubMed

    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.

  16. Haematology in dengue and dengue haemorrhagic fever.

    PubMed

    Srichaikul, T; Nimmannitya, S

    2000-06-01

    Dengue fever (DF) and dengue haemorrhagic fever (DHF) are caused by the dengue virus. The major pathophysiological hallmark that distinguishes DHF from DF is plasma leakage as a result of increased vascular permeability. Following this leakage, hypovolaemic shock occurs as a consequence of a critical plasma volume loss. Constant haematological abnormalities occurring in DHF and frequently include bone marrow suppression, leucopenia and thrombocytopenia. An enhanced immune response of the host to a secondary DV infection is a feature of DHF and leads to many consequences. These are immune complex formation, complement activation, increased histamine release and a massive release of many cytokines into the circulation, leading to shock, vasculopathy, thrombopathy and disseminated intravascular coagulation (DIC). The mechanisms underlying the bleeding in DHF are multiple. These are vasculopathy, thrombopathy and DIC. Thrombopathy consists of thrombocytopenia and platelet dysfunction. DIC is prominent in patients with shock. The most severe DIC and massive bleeding are the result of prolonged shock and cause a fatal outcome. The mechanisms of thrombopathy and DIC and the proper management of DHF are reviewed and discussed.

  17. Oxygen transport and mixing dynamics in thin films of aerotactic bacteria

    NASA Astrophysics Data System (ADS)

    Alizadeh Pahlavan, Amir; Saintillan, David

    2010-11-01

    We investigate the dynamics in suspensions of aerotactic bacteria using two different kinetic models: a gradient-detecting model, in which the bacteria detect the local oxygen gradients instantaneously, and a run-and-tumble model, in which the bacteria change their run-and-tumble frequency based on the recent temporal changes in the oxygen field. Using three-dimensional numerical simulations, we study the behavior of such suspensions in thin liquid films surrounded by oxygen baths on both sides. As the bacteria consume the dissolved oxygen, gradients form causing them to swim towards the free surfaces where the oxygen concentration is higher. In very thin films, a high oxygen concentration is observed in the liquid as a result of diffusion from the surfaces, but as the film thickness increases, a depletion layer forms in the center. The formation of this low-oxygen region is associated with the emergence of large-scale instabilities in the suspensions that enhance oxygen mixing into the liquid. These instabilities are accompanied by the formation of large plumes of high bacterial density. The bacterial migration towards the free surfaces is found to be slower in the run-and-tumble model.

  18. 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.

  19. Oxygen Transport in a Three-Dimensional Microvascular Network Incorporated with Early Tumour Growth and Preexisting Vessel Cooption: Numerical Simulation Study

    PubMed Central

    Cai, Yan; Zhang, Jie; Wu, Jie; Li, Zhi-yong

    2015-01-01

    We propose a dynamic mathematical model of tissue oxygen transport by a preexisting three-dimensional microvascular network which provides nutrients for an in situ cancer at the very early stage of primary microtumour growth. The expanding tumour consumes oxygen during its invasion to the surrounding tissues and cooption of host vessels. The preexisting vessel cooption, remodelling and collapse are modelled by the changes of haemodynamic conditions due to the growing tumour. A detailed computational model of oxygen transport in tumour tissue is developed by considering (a) the time-varying oxygen advection diffusion equation within the microvessel segments, (b) the oxygen flux across the vessel walls, and (c) the oxygen diffusion and consumption within the tumour and surrounding healthy tissue. The results show the oxygen concentration distribution at different time points of early tumour growth. In addition, the influence of preexisting vessel density on the oxygen transport has been discussed. The proposed model not only provides a quantitative approach for investigating the interactions between tumour growth and oxygen delivery, but also is extendable to model other molecules or chemotherapeutic drug transport in the future study. PMID:25695084

  20. Role of blood-oxygen transport in thermal tolerance of the cuttlefish, Sepia officinalis.

    PubMed

    Melzner, Frank; Mark, Felix C; Pörtner, Hans-Otto

    2007-10-01

    Mechanisms that affect thermal tolerance of ectothermic organisms have recently received much interest, mainly due to global warming and climate-change debates in both the public and in the scientific community. In physiological terms, thermal tolerance of several marine ectothermic taxa can be linked to oxygen availability, with capacity limitations in ventilatory and circulatory systems contributing to oxygen limitation at extreme temperatures. The present review briefly summarizes the processes that define thermal tolerance in a model cephalopod organism, the cuttlefish Sepia officinalis, with a focus on the contribution of the cephalopod oxygen-carrying blood pigment, hemocyanin. When acutely exposed to either extremely high or low temperatures, cuttlefish display a gradual transition to an anaerobic mode of energy production in key muscle tissues once critical temperatures (T(crit)) are reached. At high temperatures, stagnating metabolic rates and a developing hypoxemia can be correlated with a progressive failure of the circulatory system, well before T(crit) is reached. However, at low temperatures, declining metabolic rates cannot be related to ventilatory or circulatory failure. Rather, we propose a role for hemocyanin functional characteristics as a major limiting factor preventing proper tissue oxygenation. Using information on the oxygen binding characteristics of cephalopod hemocyanins, we argue that high oxygen affinities (= low P(50) values), as found at low temperatures, allow efficient oxygen shuttling only at very low venous oxygen partial pressures. Low venous PO(2)s limit rates of oxygen diffusion into cells, thus eventually causing the observed transition to anaerobic metabolism. On the basis of existing blood physiological, molecular, and crystallographical data, the potential to resolve the role of hemocyanin isoforms in thermal adaptation by an integrated molecular physiological approach is discussed.

  1. 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

  2. Spleen in haematological malignancies: spectrum of imaging findings

    PubMed Central

    Saboo, S S; Krajewski, K M; O'Regan, K N; Giardino, A; Brown, J R; Ramaiya, N; Jagannathan, J P

    2012-01-01

    Imaging morphology and metabolic activity of splenic lesions is of paramount importance in patients with haematological malignancies; it can alter tumour staging, treatment protocols and overall prognosis. CT, MRI and positron emission tomography (PET)/CT have been shown to be powerful tools for the non-invasive assessment of splenic involvement in various haematological malignancies. Since many haematological malignancies and non-neoplastic conditions can involve the spleen and imaging manifestations can overlap, imaging and clinical findings outside of the spleen should be looked for to narrow the differential diagnosis; confirmation can be obtained by pathological findings. Radiologists should be familiar with the cross-sectional imaging patterns of haematological malignancies involving the spleen as well as non-neoplastic splenic findings common in these patients to facilitate their care and follow-up. This pictorial review provides the common and uncommon imaging appearances and complications of various haematological malignancies involving the spleen on CT, MRI and PET/CT, and common pitfalls in diagnosis. PMID:22096219

  3. Thermophysical properties and oxygen transport in the (Ux,Pu1-x)O2 lattice

    NASA Astrophysics Data System (ADS)

    Cooper, M. W. D.; Murphy, S. T.; Rushton, M. J. D.; Grimes, R. W.

    2015-06-01

    Using molecular dynamics, the thermophysical properties of the (Ux,Pu1-x)O2 system have been investigated between 300 and 3200 K. The variation with temperature of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure, are explained in terms of defect formation and diffusivity on the oxygen sublattice. Vegard's Law is approximately observed for the thermal expansion of the solid solutions below 2000 K. Deviation from Vegard's Law above this temperature occurs due to the different superionic transition temperatures of the solid solutions (2200-2900 K). Similarly, a spike in the specific heat, associated with the superionic transition, occurs at lower temperatures in solid solutions that have a high Pu content. While oxygen diffusivity is higher in pure PuO2 than in pure UO2, lower oxygen defect enthalpies in (Ux,Pu1-x)O2 solid solutions cause higher oxygen mobility than would be expected by interpolation between the diffusivities of the end members. In comparison to UO2 and PuO2 there is considerable variety of oxygen vacancy and oxygen interstitial sites in solid solutions generating a wide range of property values. Trends in the defect enthalpies are discussed in terms of composition and the lattice parameter of (Ux,Pu1-x)O2. Comparison is made with previous work on (Ux,Th1-x)O2.

  4. Experimental Evaluation of Liquid Film Resistance in Oxygen Transport to Microbial Cells

    PubMed Central

    Borkowski, John D.; Johnson, Marvin J.

    1967-01-01

    A membrane probe was used to monitor the dissolved oxygen concentrations in continuous cultures of Candida utilis and Micrococcus roseus growing at low dissolved oxygen concentrations and various agitation levels. For the yeast fermentations, increasing the agitation level within the range of 0.1 to 0.3 w per liter lowered steady-state dissolved oxygen concentrations in the fermentor. The steady-state dissolved oxygen concentration in the fermentor was not influenced by the agitation level within the range of 0.3 to 1.8 w per liter. With M. roseus, no effect of agitation on steady-state dissolved oxygen concentrations in the fermentor was observed within the range of 0.1 to 1.8 w per liter. It was concluded that, under the conditions used, a measurable transfer barrier from the liquid to the yeast cells existed at agitation levels below 0.3 w per liter and that this barrier did not exist at agitation levels above 0.3 w per liter. The transfer barrier from the liquid to the yeast surface could be represented by a stagnant film of liquid 0.6 × 10-4 cm thick surrounding the cell at an agitation level of 0.10 w per liter. This film represented an oxygen concentration drop of 1.3 × 10-7 M from the bulk of the medium to the cells under the experimental conditions. PMID:16349771

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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.

  6. Bedside calculation of hemodynamic parameters with a hand held programmable calculator. Part II: Programs for hemodynamic and oxygen transport parameters computation.

    PubMed

    Laurent, M

    1980-01-01

    Two programs calculating oxygen transport parameters and hemodynamic values respectively are described. They may be used indifferently with HP 67 or HP 97 Hewlett Packard calculators. (Acta anaesth. belg., 1980, 31, 53-59).

  7. 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.

  8. The role of CCN family genes in haematological malignancies.

    PubMed

    Wells, J E; Howlett, M; Cheung, L C; Kees, Ursula R

    2015-09-01

    Haematological malignancies, although a broad range of specific disease types, continue to show considerable overlap in classification, and patients are treated using similar chemotherapy regimes. In this review we look at the role of the CCN family of matricellular proteins and indicate their role in nine haematological malignancies including both myeloid and lymphoid neoplasms. The potential for further haematological neoplasms with CCN family associations is argued by summarising the demonstrated role of CCN family genes in the differentiation of haematopoietic stem cells (HSC) and mesenchymal stem cells. The expanding field of knowledge encompassing CCN family genes and cancers of the HSC-lineage highlights the importance of extracellular matrix-interactions in both normal physiology and tumorigenesis of the blood, bone marrow and lymph nodes.

  9. Water, proton, and oxygen transport in high IEC, short side chain PFSA ionomer membranes: consequences of a frustrated network.

    PubMed

    Luo, Xiaoyan; Holdcroft, Steven; Mani, Ana; Zhang, Yongming; Shi, Zhiqing

    2011-10-28

    The effect of ion exchange capacity (IEC) on the water sorption properties of high IEC, short side chain (SSC) PFSA ionomer membranes, and the relationships between water content, proton conductivity, proton mobility, water permeation, oxygen diffusion, and oxygen permeation are investigated. SSC PFSA ionomer membranes possessing 1.3, 1.4, and 1.5 mmol g(-1) IEC are compared to a series of long side chain (LSC) PFSA ionomer membranes ranging in IEC from 0.9 to 1.13 mmol g(-1). At 25 °C, fully-hydrated SSC ionomer membranes are characterized as possessing higher water contents (56-75 vol%), moderate λ values (15-18), high analytical acid concentrations (2-2.8 M), and moderate conductivity (88-115 mS/cm); but lower than anticipated effective proton mobility. Complementary measurements of water permeability, oxygen diffusion, and oxygen permeability also yield lower than expected values given their much higher water contents. Potential benefits afforded by reducing the side chain length of PFSA ionomer membranes, such as increased crystallinity, higher IEC, and high hydrated acid concentration are offset by a less-developed, frustrated hydrophilic percolation network, which provides a motivation for future improvements of transport properties for this class of material.

  10. 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.

  11. Atomic oxygen between 80 and 120 km - Evidence for a latitudinal variation in vertical transport near the mesopause

    NASA Technical Reports Server (NTRS)

    Wasser, B.; Donahue, T. M.

    1979-01-01

    Analysis of the OGO 6 OI green line nightglow photometer experiment has been carried out for eight 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. The results obtained show that the vertical gradient of the emission rate between 95 and 80 km alternates between regions of very rapid variation and very slow variation spaced on a scale of 5-10 deg of latitude. Maps showing isoemissivity contours and isodensity contours for atomic oxygen concentration in vertical meridional planes are presented. The densities are computed under three assumptions concerning excitation mechanisms. Comparisons of the vertical variations of oxygen density with the results of a time dependent theory suggest the regions of strong downward transport alternate in latitude 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.

  12. 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.

  13. Haematology of the racing Thoroughbred in Australia 2: haematological values compared to performance.

    PubMed

    Revington, M

    1983-04-01

    Eight hundred and sixteen blood samples were collected from Thoroughbred racehorses at the race track, 1 to 3 h before racing, and subjected to routine haematological examination. Attempts were made to correlate the haemogram with subsequent performance. Races were classified according to age, class and distance, and performances were grouped according to distance from the winner. Intra- and interclass comparisons were made but no relationship emerged between racing performance and the haemogram. The haemograms of individual horses on different occasions were compared with subsequent performance, but no consistent or significant relationships were apparent. The extent of the rise in red and white cell parameters between horses at rest and immediately before racing were examined as indicators of performance, but no correlations found. It was concluded that under the conditions of this survey no relationship existed between the haemogram of the Thoroughbred racehorse and its racing performance.

  14. 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.

  15. 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.

  16. Normal and clinical haematology of captive cranes (Gruiformes).

    PubMed

    Hawkey, C; Samour, J H; Ashton, D G; Hart, M G; Cindery, R N; Ffinch, J M; Jones, D M

    1983-01-01

    Fall blood counts on 56 clinically normal cranes of nine different species have provided reference values for the interpretation of haematological changes in 13 cranes presenting with abnormal clinical signs. Hypochromic anaemia, heterophilia and lymphocytosis were found in birds with probable Mycobacterium avium infection and heterophilia and lymphocytosis in birds with bumblefoot, arthritis, nephrosis and cardiac myopathy. In several of the cases with heterophilia and lymphocytosis the fibrinogen level was also raised. A senile bird with thickened heart valves showed macrocytosis. The potential diagnostic value of clinical haematology in cranes is discussed.

  17. Autoimmune haematological disorders in two Italian children with Kabuki syndrome.

    PubMed

    Giordano, Paola; Lassandro, Giuseppe; Sangerardi, Maria; Faienza, Maria Felicia; Valente, Federica; Martire, Baldassarre

    2014-01-25

    Kabuki syndrome (also called Niikawa-Kuroki syndrome) is a rare genetic disease described for the first time in Japan, characterised by anomalies in multiple organ systems and often associated with autoimmune disorders and impaired immune response. We herein report the clinical history, the therapeutic approach and the outcome of two children with Kabuki syndrome who developed autoimmune haematological disorders (haemolytic anaemia and immune thrombocytopenia). Factors regarding differential diagnosis and interventions in better management of this syndrome and its complications are discussed. This is the first report of Italian children with autoimmune haematological disorders complicating Kabuki syndrome.

  18. Textured Nanoporous Mo:BiVO4 Photoanodes with High Charge Transport and Charge Transfer Quantum Efficiencies for Oxygen Evolution

    SciTech Connect

    Nair, Vineet; Perkins, Craig L.; Lin, Qiyin; Law, Matt

    2016-04-01

    We have developed a simple spin coating method to make high-quality nanoporous photoelectrodes of monoclinic BiVO4 and studied the ability of these electrodes to transport photogenerated carriers to oxidize sulfite and water. Samples containing molybdenum and featuring [001] out-of-plane crystallographic texture show a photocurrent and external quantum efficiency (EQE) for sulfite oxidation as high as 3.1 mA cm-2 and 60%, respectively, at 1.23 V versus reversible hydrogen electrode. By using an optical model of the electrode stack to accurately determine the fraction of electrode absorptance due to the BiVO4 active layer, we estimate that on average 70 +/- 5% of all photogenerated carriers escape recombination. A comparison of internal quantum efficiency as a function of film processing, illumination direction, and film thickness shows that electron transport is efficient and hole transport limits the photocurrent (hole diffusion length <40 nm). We find that Mo addition primarily improves electron transport and texturing mostly improves hole transport. Mo enhances electron transport by thinning the surface depletion layer or passivating traps and recombination centers at grain boundaries and interfaces, while improved hole transport in textured films may result from more efficient lateral hole extraction due to the texturing itself or the reduced density of deep gap states observed in photoemission measurements. Photoemission data also reveal that the films have bismuth-rich, vanadium- and oxygen-deficient surface layers, while ion scattering spectroscopy indicates a Bi-V-O surface termination. Without added catalysts, the plain BiVO4 electrodes oxidized water with an initial photocurrent and peak EQE of 1.7 mA cm-2 and 30%, respectively, which equates to a hole transfer efficiency to water of >64% at 1.23 V. The electrodes quickly photocorrode during water oxidation but show good stability during sulfite oxidation and indefinite stability in the dark. By improving

  19. 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.

  20. 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.

  1. 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…

  2. 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.

  3. Symmetry breaking in nanostructure development of carbogenic molecular sieves: Effects of morphological pattern formation on oxygen and nitrogen transport

    SciTech Connect

    Kane, M.S.; Goellner, J.F.; Foley, H.C.

    1996-08-01

    A comprehensive study has been undertaken to establish the primary factors that control transport of oxygen and nitrogen in polymer-derived carbogenic molecular sieves (CMS). Characterization of the nanostructure of CMS derived from poly(furfuryl alcohol) (PFA) indicates that significant physical and chemical reorganization occurs as a function of synthesis temperature. Spectroscopic measurements show a drastic decrease in oxygen and hydrogen functionality with increasing pyrolysis temperature. Structural reorganization and elimination of these heteroatoms lead to a measurable increase in the unpaired electron density in these materials. High-resolution transmission electron microscopy and powder neutron diffraction are used to probe the corresponding changes in the physical structural features in the CMS. These indicate that as the pyrolysis temperature is increased, the structure of the CMS transforms from one that is disordered and therefore highly symmetric to one that is more ordered on a length scale of 15 {Angstrom} and hence less symmetric. This structural transformation process, one of symmetry breaking and pattern formation, if often observed in other nonlinear dissipative systems, but not in solids. Symmetry breaking provides the driving force for these high-temperature reorganizations, but unlike most dissipative systems, these less-symmetric structures remain frozen in place when energy is no longer applied. The impact of these nanostructural reorganizations on the molecular sieving character of the CMS is studied in terms of the physical separation of oxygen and nitrogen. 40 refs., 14 figs., 3 tabs.

  4. 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

  5. Bacillus cereus bacteraemia: comparison between haematologic and nonhaematologic patients.

    PubMed

    Tusgul, S; Prod'hom, G; Senn, L; Meuli, R; Bochud, P-Y; Giulieri, S G

    2017-01-01

    Bacillus cereus bacteraemia can be severe, especially among patients with haematologic malignancy. We retrospectively reviewed first episodes of true B. cereus bacteraemia (more than one positive bottle plus signs of infection) at our institution between 1997 and 2013 with the aim to compare haematologic versus nonhaematologic patients and analyse episodes with complicated outcome. Among 56 episodes of positive-blood cultures for B. cereus, 21 were considered significant. Median age was 54 years (range 23-82 years). Ten patients (48%) had a haematologic malignancy; all were neutropenic at the time of B. cereus bacteraemia. Nonhaematologic patients were either intravenous drug users (n = 3, 14%), polytraumatized (n = 3, 14%) or had multiple chronic comorbidities (n = 5, 24%). Most episodes were hospital acquired (15, 71%). Sources of bacteraemia were intravascular catheter (n = 11, 52%), digestive tract (n = 6, 29%), drug injection (n = 3, 14%) and wound (n = 1, 5%). Adequate antibiotic therapy was provided to 18 patients (86%) during a median of 17 days (range 2-253 days). The intravascular catheter was removed in eight cases (42%). Three haematologic patients had a complicated course with neurologic complications (meningoencephalitis and cerebral abscesses). Complications appeared to be associated with catheter infection (100% of complicated cases vs. 29% of noncomplicated cases). In conclusion, B. cereus bacteraemia can have a complicated course in a subset of patients, mainly those with haematologic malignancy. Catheter infection may be associated with a worse outcome with frequent neurologic complications.

  6. Gas-liquid slug-flow oxygen transport and non-invasive biomass estimation in hollow-fiber reactors

    SciTech Connect

    Smith, W.J.

    1989-01-01

    Maintenance of non-limiting concentrations of dissolved gases at the surface of a particulate biocatalyst is a formidable barrier to the development of ultra-compact bioreactors. The method proposed here for supplying dissolved gases resembles the microcirculation of vertebrates. In the microcirculation, two phases, oxygen-rich hemoglobin-packed erythrocytes and nutrient-rich plasma, pass alternately through the capillaries. In slug-flow membrane bioreactors, two phases, oxygen-rich gas bubbles and slugs of aqueous nutrient medium, flow alternately on one side of a semipermeable membrane while cells grow on the opposite side. Protein synthesis rates were measured for Bacillus licheniformis 749C cultures immobilized in slug-flow hollow-fiber membrane reactors. The cultures required oxygen for growth and protein synthesis. A mathematical model of slug-flow identified the operating conditions corresponding to either continuous or periodic oxygen supply within the reactors. Synthesis rates within the slug-flow reactors were higher than those predicted by the model; the model apparently underestimated concentrations of soluble nutrients in the biomass. Non-invasive estimates of the total immobilized biomass are needed to monitor and control the biomass density, and hence the transport properties of the biomass phase. Investigators have used two non-invasive methods: in situ monitoring of an aggregate property, such as electrical conductivity; and inferential estimates based on substrate consumption and metabolic models. Techniques were developed to estimate immobilized biomass concentrations and growth rates from sulfur mass balances. Additionally, global mass balances showed that time-averaged biomass specific growth rates can be estimated from effluent concentrations of any substrate with a finite yield coefficient.

  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.

  8. Oxygen, water, and sodium chloride transport in soft contact lenses materials.

    PubMed

    Gavara, Rafael; Compañ, Vicente

    2016-07-21

    Oxygen permeability, diffusion coefficient of the sodium ions and water flux and permeability in different conventional hydrogel (Hy) and silicone-hydrogel (Si-Hy) contact lenses have been measured experimentally. The results showed that oxygen permeability and transmissibility requirements of the lens have been addressed through the use of siloxane containing hydrogels. In general, oxygen and sodium chloride permeability values increased with the water content of the lens but there was a percolation phenomenon from a given value of water uptake mainly in the Si-Hy lenses which appeared to be related with the differences between free water and bound water contents. The increase of ion permeability with water content did not follow a unique trend indicating a possible dependence of the chemical structure of the polymer and character ionic and non-ionic of the lens. Indeed, the salt permeability values for silicone hydrogel contact lenses were one order of magnitude below those of conventional hydrogel contact lenses, which can be explained by a diffusion of sodium ions occurring only through the hydrophilic channels. The increase of the ionic permeability in Si-Hy materials may be due to the confinement of ions in nanoscale water channels involving possible decreased degrees of freedom for diffusion of both water and ions. In general, ionic lenses presented values of ionic permeability and diffusivity higher than most non-ionic lenses. The tortuosity of the ionic lenses is lower than the non-ionic Si-Hy lenses. Frequency 55 and PureVision exhibited the highest water permeability and flux values and, these parameters were greater for ionic Si-Hy lenses than for ionic conventional hydrogel lenses. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  9. Visualizing dissolved oxygen transport for liquid ventilation in an in vitro model of the human airways

    NASA Astrophysics Data System (ADS)

    Janke, T.; Bauer, K.

    2017-04-01

    Up until to now, the measurement of dissolved oxygen concentrations during liquid ventilation is limited to the determination of averaged concentrations of the liquid entering or leaving the body. The work presented in this paper aims to extend the possible measurement techniques in the research of liquid ventilation. Therefore optical measurements of the dissolved oxygen concentration, using a luminescent sensor dye, are performed. The preparation of a suitable sensor liquid, based on the metal complex Dichlorotris(1,10)–(phenanthroline)ruthenium(II), is presented. A transparent simplified human lung geometry is used for conducting the experiments. Inspiratory as well as expiratory flow at three different constant flow rates is investigated, covering the flow regimes \\text{Re}=83 –333 and \\text{Pe}=33 300 –133 000. The applied measurement technique is capable to reveal distinctive concentration patterns during inspiration and expiration caused by the laminar flow characteristics. Allowing a sufficiently long flow duration, local concentration inhomogeneities disappear and an exponential rise and decay of the mean values can be observed for inspiration and expiration.

  10. Gene cooption and convergent evolution of oxygen transport hemoglobins in jawed and jawless vertebrates

    PubMed Central

    Hoffmann, Federico G.; Opazo, Juan C.; Storz, Jay F.

    2010-01-01

    Natural selection often promotes evolutionary innovation by coopting preexisting genes for new functions, and this process may be greatly facilitated by gene duplication. Here we report an example of cooptive convergence where paralogous members of the globin gene superfamily independently evolved a specialized O2 transport function in the two deepest branches of the vertebrate family tree. Specifically, phylogenetic evidence demonstrates that erythroid-specific O2 transport hemoglobins evolved independently from different ancestral precursor proteins in jawed vertebrates (gnathostomes) and jawless fish (cyclostomes, represented by lamprey and hagfish). A comprehensive phylogenetic analysis of the vertebrate globin gene superfamily revealed that the erythroid hemoglobins of cyclostomes are orthologous to the cytoglobin protein of gnathostome vertebrates, a hexacoordinate globin that has no O2 transport function and that is predominantly expressed in fibroblasts and related cell types. The phylogeny reconstruction also revealed that vertebrate-specific globins are grouped into four main clades: (i) cyclostome hemoglobin + cytoglobin, (ii) myoglobin + globin E, (iii) globin Y, and (iv) the α- and β-chain hemoglobins of gnathostomes. In the hemoglobins of gnathostomes and cyclostomes, multisubunit quaternary structures provide the basis for cooperative O2 binding and allosteric regulation by coupling the effects of ligand binding at individual subunits with interactions between subunits. However, differences in numerous structural details belie their independent origins. This example of convergent evolution of protein function provides an impressive demonstration of the ability of natural selection to cobble together complex design solutions by tinkering with different variations of the same basic protein scaffold. PMID:20660759

  11. 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

  12. Integrated device for the measurement of systemic and local oxygen transport during physical exercise.

    PubMed

    Pollonini, Luca; Re, Rebecca; Simpson, Richard J; Dacso, Clifford C

    2012-01-01

    Current methods for monitoring exercise exertion rely upon heart rate monitors, which represent a crude and lagging indicator of conditioning. The rationale for the present study is that both systemic and local metabolic mechanisms are responsible for physical performance, and therefore they should be simultaneously quantified to achieve an objective assessment of human conditioning. We propose a compact, wearable near-infrared spectroscopy (NIRS) device integrated with electrocardiography (ECG) and photoplethysmography (PPG) to simultaneously assess the cardiovascular and local response to exercise. The system was tested on subjects performing a graded maximal exercise by comparing our readings with metabolic variables measured with respiratory gas analysis. We found strong correlations between local deoxyhemoglobin concentration [HHb], heart rate and oxygen uptake, as well as between oxyhemoglobin concentration [HbO(2)] and stroke volume. This study shows that combined NIRS, ECG and PPG measurements yield useful information to understand the interplay between systemic and local muscular responses to exercise.

  13. Decreases in Maximal Oxygen Uptake Following Long-duration Spaceflight: Role of Convective and Diffusive O2 Transport Mechanisms.

    PubMed

    Ade, Carl J; Broxterman, Ryan M; Moore, Alan; Barstow, Thomas J

    2017-02-02

    We have previously predicted that the decrease in maximal oxygen uptake (VO2max) that accompanies time in microgravity reflects decrements in both convective and diffusive O2 transport to the mitochondria of the contracting myocytes. The aim of this investigation was therefore to quantify the relative changes in convective O2 transport (QO2) and O2 diffusing capacity (DO2) following long duration spaceflight. In 9 astronauts, resting hemoglobin concentration ([Hb]), VO2max, maximal cardiac output (QTmax), and differences in arterial and venous O2 contents (CaO2-CvO2) were obtained retrospectively for International Space Station Increments 19 through 33 (April 2009-November 2012). QO2 and DO2 were calculated from these variables via integration of Fick's Principle of Mass Conservation and Fick's Law of Diffusion. VO2max significantly decreased from pre- to post-flight (-53.9 ± 45.5%, P =0.008). The significant decrease in Q ̇_Tmax (-7.8±9.1%, P =0.05), despite an unchanged [Hb] resulted in a significantly decreased QO2 (-11.4±10.5%, P = 0.02). DO2 significantly decreased from pre- to post-flight by -27.5±24.5% (P =0.04), as did the peak CaO2-CvO2 (-9.2±7.5%, P =0.007). Using linear regression analysis, changes in VO2max were significantly correlated with changes in DO2 (R2=0.47; P = 0.04). These data suggest that space flight decreases both convective and diffusive O2 transport. These results have practical implications for future long-duration space missions and highlight the need to resolve the specific mechanisms underlying these spaceflight-induced changes along the O2 transport pathway.

  14. 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.

  15. Enhanced Nitrogen Loss by Eddy-Induced Vertical Transport in the Offshore Peruvian Oxygen Minimum Zone.

    PubMed

    Callbeck, Cameron M; Lavik, Gaute; Stramma, Lothar; Kuypers, Marcel M M; Bristow, Laura A

    2017-01-01

    The eastern tropical South Pacific (ETSP) upwelling region is one of the ocean's largest sinks of fixed nitrogen, which is lost as N2 via the anaerobic processes of anammox and denitrification. One-third of nitrogen loss occurs in productive shelf waters stimulated by organic matter export as a result of eastern boundary upwelling. Offshore, nitrogen loss rates are lower, but due to its sheer size this area accounts for ~70% of ETSP nitrogen loss. How nitrogen loss and primary production are regulated in the offshore ETSP region where coastal upwelling is less influential remains unclear. Mesoscale eddies, ubiquitous in the ETSP region, have been suggested to enhance vertical nutrient transport and thereby regulate primary productivity and hence organic matter export. Here, we investigated the impact of mesoscale eddies on anammox and denitrification activity using 15N-labelled in situ incubation experiments. Anammox was shown to be the dominant nitrogen loss process, but varied across the eddy, whereas denitrification was below detection at all stations. Anammox rates at the eddy periphery were greater than at the center. Similarly, depth-integrated chlorophyll paralleled anammox activity, increasing at the periphery relative to the eddy center; suggestive of enhanced organic matter export along the periphery supporting nitrogen loss. This can be attributed to enhanced vertical nutrient transport caused by an eddy-driven submesoscale mechanism operating at the eddy periphery. In the ETSP region, the widespread distribution of eddies and the large heterogeneity observed in anammox rates from a compilation of stations suggests that eddy-driven vertical nutrient transport may regulate offshore primary production and thereby nitrogen loss.

  16. Enhanced Nitrogen Loss by Eddy-Induced Vertical Transport in the Offshore Peruvian Oxygen Minimum Zone

    PubMed Central

    Callbeck, Cameron M.; Lavik, Gaute; Stramma, Lothar; Kuypers, Marcel M. M.; Bristow, Laura A.

    2017-01-01

    The eastern tropical South Pacific (ETSP) upwelling region is one of the ocean’s largest sinks of fixed nitrogen, which is lost as N2 via the anaerobic processes of anammox and denitrification. One-third of nitrogen loss occurs in productive shelf waters stimulated by organic matter export as a result of eastern boundary upwelling. Offshore, nitrogen loss rates are lower, but due to its sheer size this area accounts for ~70% of ETSP nitrogen loss. How nitrogen loss and primary production are regulated in the offshore ETSP region where coastal upwelling is less influential remains unclear. Mesoscale eddies, ubiquitous in the ETSP region, have been suggested to enhance vertical nutrient transport and thereby regulate primary productivity and hence organic matter export. Here, we investigated the impact of mesoscale eddies on anammox and denitrification activity using 15N-labelled in situ incubation experiments. Anammox was shown to be the dominant nitrogen loss process, but varied across the eddy, whereas denitrification was below detection at all stations. Anammox rates at the eddy periphery were greater than at the center. Similarly, depth-integrated chlorophyll paralleled anammox activity, increasing at the periphery relative to the eddy center; suggestive of enhanced organic matter export along the periphery supporting nitrogen loss. This can be attributed to enhanced vertical nutrient transport caused by an eddy-driven submesoscale mechanism operating at the eddy periphery. In the ETSP region, the widespread distribution of eddies and the large heterogeneity observed in anammox rates from a compilation of stations suggests that eddy-driven vertical nutrient transport may regulate offshore primary production and thereby nitrogen loss. PMID:28122044

  17. Mechanisms of photodoping in oxygen-deficient YBa2Cu3Ox films studied by in situ transport measurements

    NASA Astrophysics Data System (ADS)

    Stockinger, C.; Markowitsch, W.; Lang, W.; Kula, W.; Sobolewski, Roman

    1998-04-01

    In situ studies of the superconducting and normal-state transport properties in partially oxygen-depleted, metallic YBa2Cu3Ox (Tc,mid~52 K) thin films exposed to long-term white-light illumination (photodoping) are reported. We observed that the effects of photoexcitation strongly depended on the temperature at which the photodoping was performed. The Hall number increased during the illumination in the entire tested temperature range from 70 to 290 K, with the strongest increase near room temperature, whereas, the Hall mobility increased steadily only upon low-temperature illumination. At temperatures above 250 K, it showed an abrupt initial increase followed by a long-term decrease. At high temperatures, the Hall quantities react on the impact of light excitation independently from each other, which strongly suggests that both the photoassisted oxygen ordering and charge-transfer mechanisms contribute to photodoping, the former acting mainly on the mobility, while the latter on the density of charge carriers. The photoinduced enhancement of the superconducting transition temperature Tc exhibited essentially the same temperature dependence as the enhancement of the Hall number, being largest (ΔTc~2.6 K) for the illumination performed at high temperatures. Thus, the Tc enhancement results from the change of the density more likely than of the mobility of the charge carriers.

  18. Structure of the Zymomonas mobilis respiratory chain: oxygen affinity of electron transport and the role of cytochrome c peroxidase.

    PubMed

    Balodite, Elina; Strazdina, Inese; Galinina, Nina; McLean, Samantha; Rutkis, Reinis; Poole, Robert K; Kalnenieks, Uldis

    2014-09-01

    The genome of the ethanol-producing bacterium Zymomonas mobilis encodes a bd-type terminal oxidase, cytochrome bc1 complex and several c-type cytochromes, yet lacks sequences homologous to any of the known bacterial cytochrome c oxidase genes. Recently, it was suggested that a putative respiratory cytochrome c peroxidase, receiving electrons from the cytochrome bc1 complex via cytochrome c552, might function as a peroxidase and/or an alternative oxidase. The present study was designed to test this hypothesis, by construction of a cytochrome c peroxidase mutant (Zm6-perC), and comparison of its properties with those of a mutant defective in the cytochrome b subunit of the bc1 complex (Zm6-cytB). Disruption of the cytochrome c peroxidase gene (ZZ60192) caused a decrease of the membrane NADH peroxidase activity, impaired the resistance of growing culture to exogenous hydrogen peroxide and hampered aerobic growth. However, this mutation did not affect the activity or oxygen affinity of the respiratory chain, or the kinetics of cytochrome d reduction. Furthermore, the peroxide resistance and membrane NADH peroxidase activity of strain Zm6-cytB had not decreased, but both the oxygen affinity of electron transport and the kinetics of cytochrome d reduction were affected. It is therefore concluded that the cytochrome c peroxidase does not terminate the cytochrome bc1 branch of Z. mobilis, and that it is functioning as a quinol peroxidase.

  19. Moral distress in nurses in oncology and haematology units.

    PubMed

    Lazzarin, Michela; Biondi, Andrea; Di Mauro, Stefania

    2012-03-01

    One of the difficulties nurses experience in clinical practice in relation to ethical issues in connection with young oncology patients is moral distress. In this descriptive correlational study, the Moral Distress Scale-Paediatric Version (MDS-PV) was translated from the original language and tested on a conventional sample of nurses working in paediatric oncology and haematology wards, in six north paediatric hospitals of Italy. 13.7% of the total respondents claimed that they had changed unit or hospital due to moral distress. The items with the highest mean intensity in the sample were almost all connected with medical and nursing competence and have considerably higher values than frequency. The instrument was found to be reliable. The results confirmed the validity of the MDS-PV (Cronbach's alpha = 0.959). This study represents the first small-scale attempt to validate MDS-PV for use in paediatric oncology-haematology nurses in Italy.

  20. Next-generation sequencing - feasibility and practicality in haematology.

    PubMed

    Kohlmann, Alexander; Grossmann, Vera; Nadarajah, Niroshan; Haferlach, Torsten

    2013-03-01

    Next-generation sequencing platforms have evolved to provide an accurate and comprehensive means for the detection of molecular mutations in heterogeneous tumour specimens. Here, we review the feasibility and practicality of this novel laboratory technology. In particular, we focus on the utility of next-generation sequencing technology in characterizing haematological neoplasms and the landmark findings in key haematological malignancies. We also discuss deep-sequencing strategies to analyse the constantly increasing number of molecular markers applied for disease classification, patient stratification and individualized monitoring of minimal residual disease. Although many facets of this assay need to be taken into account, amplicon deep-sequencing has already demonstrated a promising technical performance and is being continuously developed towards routine application in diagnostic laboratories so that an impact on clinical practice can be achieved.

  1. 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.

  2. 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.

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

    DOE PAGES

    Yang, Sangmo; Lee, Shinbuhm; Jian, Jie; ...

    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

  4. 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

    2015-10-08

    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.

  5. 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

  6. 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

  7. 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.

  8. Oxygen consumption and active sodium and chloride transport in bovine tracheal epithelium.

    PubMed Central

    Durand, J; Durand-Arczynska, W; Schoenenweid, F

    1986-01-01

    The O2 consumption (Jr) and the short-circuit current (Ji) were measured simultaneously in bovine tracheal epithelium in vitro. In this tissue, Ji is the sum of two active transport processes, Cl- secretion and Na+ absorption. Jr was determined from the decrease of PO2 in the incubation solution, at 37 +/- 0.05 degrees C and at a PO2 around 600 torr. Microbial contamination and leaks of dissolved O2 from the solution never exceeded 4% of the rate of PO2 decrease due to the O2 consumption of the tissue. Ji and Jr were stable over 5 h of incubation under standard conditions. Ji was 106 +/- 4 nequiv min-1 cm-2 and Jr was 39.8 +/- 1.1 nmol O2 min-1 cm-2 (mean +/- S.E., n = 46). Ji was varied with several agents known to affect ion transport across the tracheal epithelium. Na+ absorption was inhibited partly with amiloride or completely following Na+ substitution with choline. Cl- secretion was selectively suppressed by furosemide. Ji was also reduced to a very low level, using ouabain or K+ suppression to inhibit the Na+-K+-ATPase. All these manoeuvres resulted in significant reductions of both Ji and Jr. Basal Jr was not affected when Ji was modified. A plot of the relative change in suprabasal Jr versus the relative change of Ji gave a straight line (r = 0.98, n = 60). A plot using absolute values yielded a stoichiometric ratio of 13.9 ions per O2 molecule, for Na+ as well as for Cl-. The stoichiometric ratio was also calculated for each experiment. Its mean value was 14.9 ions per O2 molecule. The population of the ratios was widely dispersed, but this was explained as a predictable statistical phenomenon. PMID:3723416

  9. External quality assessment scheme for haematology in Germany.

    PubMed

    Heller, S

    1995-01-01

    Quality control in haematology is performed in Germany for 20 years. Both cell count, haemoglobin measurement and differential count on smear with morphology exercise and probably diagnosis will be demanded by the participants. Until now this quality control is not mandatory, even efforts are done to change this circumstance, given by the main input of diagnostic value due to haematology results. So this regulation will be changed very soon, in order to submit haematological laboratories to governmental control, effected by the BAK (Bundesärztekammer), as already is done in clinical chemistry. For this EQA the participants cannot expected any financial support by any organization, nor public health, nor private assurance. The role of referee laboratories and reference values as well as difficulties for the adequate reference material are discussed. For the differential count other limits have to be established: recognition of pathological blood films is one of the most important point (in sense of morphological exercise) to ensure broad knowledge of "flag interpretation". Since the last year quality control for reticulocyte count and flow cytometry for immune status and leukemia-differentiation has been established.

  10. Iron-induced reactive oxygen species mediate transporter DMT1 endocytosis and iron uptake in intestinal epithelial cells.

    PubMed

    Esparza, Andrés; Gerdtzen, Ziomara P; Olivera-Nappa, Alvaro; Salgado, J Cristian; Núñez, Marco T

    2015-10-15

    Recent evidence shows that iron induces the endocytosis of the iron transporter dimetal transporter 1 (DMT1) during intestinal absorption. We, and others, have proposed that iron-induced DMT1 internalization underlies the mucosal block phenomena, a regulatory response that downregulates intestinal iron uptake after a large oral dose of iron. In this work, we investigated the participation of reactive oxygen species (ROS) in the establishment of this response. By means of selective surface protein biotinylation of polarized Caco-2 cells, we determined the kinetics of DMT1 internalization from the apical membrane after an iron challenge. The initial decrease in DMT1 levels in the apical membrane induced by iron was followed at later times by increased levels of DMT1. Addition of Fe(2+), but not of Cd(2+), Zn(2+), Cu(2+), or Cu(1+), induced the production of intracellular ROS, as detected by 2',7'-dichlorofluorescein (DCF) fluorescence. Preincubation with the antioxidant N-acetyl-l-cysteine (NAC) resulted in increased DMT1 at the apical membrane before and after addition of iron. Similarly, preincubation with the hydroxyl radical scavenger dimethyl sulfoxide (DMSO) resulted in the enhanced presence of DMT1 at the apical membrane. The decrease of DMT1 levels at the apical membrane induced by iron was associated with decreased iron uptake rates. A kinetic mathematical model based on operational rate constants of DMT1 endocytosis and exocytosis is proposed. The model qualitatively captures the experimental observations and accurately describes the effect of iron, NAC, and DMSO on the apical distribution of DMT1. Taken together, our data suggest that iron uptake induces the production of ROS, which modify DMT1 endocytic cycling, thus changing the iron transport activity at the apical membrane.

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

    PubMed Central

    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

  12. 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

  13. Thermophysical properties and oxygen transport in (Thx,Pu1-x)O2

    SciTech Connect

    Galvin, C. O. T.; Cooper, M. W. D.; Rushton, M. J. D.; Grimes, R. W.

    2016-10-31

    Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1–x)O2 (0 ≤ x ≤ 1) between 300–3500 K. Specifically, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Thx,Pu1–x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen diffusivity for (Thx,Pu1–x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1–x)O2 than PuO2 and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder.

  14. A compartment model of alveolar-capillary oxygen diffusion with ventilation-perfusion gradient and dynamics of air transport through the respiratory tract.

    PubMed

    Jaworski, Jacek; Redlarski, Grzegorz

    2014-08-01

    This paper presents a model of alveolar-capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differential equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models, as well as the influence of ventilation-perfusion mismatch on the oxygen diffusion. The model is verified based on simulation results of varying exercise intensities and statistical calculations of the results obtained during various clinical trials. The benefit of the approach proposed is its application in simulation-based research aimed to generate quantitative data of normal and pathological conditions. Based on the model presented, taking into account many essential physiological processes and air transport dynamics, comprehensive and combined studies of the respiratory efficiency can be performed. The impact of physical exercise, precise changes in respiratory tract mechanics and alterations in breathing pattern can be analyzed together with the impact of various changes in alveolar-capillary oxygen diffusion. This may be useful in simulation of effects of many severe medical conditions and increased activity level.

  15. 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.

  16. Lon-Mediated Proteolysis of the FeoC Protein Prevents Salmonella enterica from Accumulating the Fe(II) Transporter FeoB under High-Oxygen Conditions

    PubMed Central

    Kim, Hyunkeun; Lee, Hwiseop

    2014-01-01

    The Salmonella Feo system consists of the FeoA, FeoB, and FeoC proteins and mediates ferrous iron [Fe(II)] import. FeoB is an inner membrane protein that, along with contributions from two small hydrophilic proteins, FeoA and FeoC, transports Fe(II). We previously reported that FeoC binds to and protects the FeoB transporter from FtsH-mediated proteolysis. In the present study, we report proteolytic regulation of FeoC that occurs in an oxygen-dependent fashion. While relatively stable under low-oxygen conditions, FeoC was rapidly degraded by the Lon protease under high-oxygen conditions. The putative Fe-S cluster of FeoC seemed to function as an oxygen sensor to control FeoC stability, as evidenced by the finding that mutation of the putative Fe-S cluster-binding site greatly increased FeoC stability under high-oxygen conditions. Salmonella ectopically expressing the feoB and feoC genes was able to accumulate FeoB and FeoC only under low-oxygen conditions, suggesting that FeoC proteolysis prevents Salmonella from accumulating the FeoB transporter under high-oxygen conditions. Finally, we propose that Lon-mediated FeoC proteolysis followed by FtsH-mediated FeoB proteolysis helps Salmonella to avoid uncontrolled Fe(II) uptake during the radical environmental changes encountered when shifting from low-iron anaerobic conditions to high-iron aerobic conditions. PMID:25313398

  17. 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.

  18. Anisotropy of the Transport Properties in Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) (110) Thin Films

    NASA Astrophysics Data System (ADS)

    Wu, Judy Zhihong

    The anisotropy of the transport properties was studied systematically on high-quality epitaxial YBCO (110) thin-films obtained by both dc magnetron-sputtering and pulsed laser-ablation on single crystal (110) SrTiO _3 substrates. These films have in-plane alignment of the c-axis of YBCO, which is essential to the transport study of the anisotropy between the ab-plane and the c-axis. Along the c-axis, rho shows a semiconductor-like upturn as T decreases and a metallic T-linear behavior along the Cu-O plane. This confirms the correlation between the semiconductor-like rho along the c-axis and slight oxygen -deficiency in YBCO. As point-defects are introduced into the thin-film by the 200 keV proton-irradiation, the rho-anisotropy dramatically changes. Along the Cu-O planes, these defects contribute only a residual rho as in normal metals. Along the c-axis, rho is significantly reduced. A "phase transition" from semiconductor-like to metal-like is completed at a low proton dose of 6times10 ^{14} ions/cm^2 , where little effect is observed on T_ {c} and rho_{ab }. This suggests that the unusual normal-state transport properties are irrelevant to the mechanism of HTS. In the superconducting state, the J_ {c,trans} has been measured as functions of T, H, and the direction of H. The T-dependence along the Cu-O plane fits the vortex-glass model while along the c-axis, it fits the Josephson tunnel-junction model. This observation implies that the extrinsic weak-link effect determines J_{c,trans} along the Cu-O plane while the intrinsic tunnelling of the charge carriers limits J_{c,trans } along the c-axis. Similar measurements have also been conducted on YBCO a-, c-, and (113)-oriented thin films. Intrinsic pinning is the strongest pinning effect in YBCO despite the orientation of the film. J _{c}-anisotropy in different field directions is due to the anisotropy of the pinning-effect. The surface pinning-effect is observed (for the first time) on YBCO. It becomes visible

  19. Haematological complications in otherwise healthy children hospitalized for varicella.

    PubMed

    Elena, Bozzola; Anna, Quondamcarlo; Andrzej, Krzysztofiak; Elisabetta, Pandolfi; Laura, Lancella; Alberto, Tozzi

    2011-02-11

    Although varicella is commonly regarded as a mild childhood disease, complications may occur and frequently require hospitalization. The aim of this study was to establish the type and frequency of varicella complications among hospitalized paediatric patients over a 4.5-year period. This analysis included the medical charts of 306 patients admitted to the Infectious Disease Unit, Children Hospital Bambino Gesù, Roma, Italy from 2006 to 2010 for varicella disease. The most common complications were haematological disorders (41.5%) followed by neurological ones (23.5%). Varicella vaccination in childhood immunization program must be increased.

  20. Pitfalls in the use of multicolour flow cytometry in haematology.

    PubMed

    Johansson, Ulrika; Macey, Marion

    2011-07-01

    Multicolour flow cytometry in haematology has developed considerably in recent years. The ability to analyse eight or more colours of fluorescence on millions of cells in a matter of minutes has enabled the provision of rapid and reliable measures of minimal residual disease for clinicians. The use of multicolour analysis has also enabled more specific characterisation of presenting leukaemias and lymphomas. However, there has not been a concomitant increase in the knowledge and experience of the flow cytometrists to deal with certain problems associated with this more complex analysis.

  1. Haematological abnormalities in acute pancreatitis. A prospective study.

    PubMed Central

    Murphy, D.; Imrie, C. W.; Davidson, J. F.

    1977-01-01

    Twenty-five patients with acute pancreatitis were studied prospectively in the first week of their admission using haematological and coagulation tests. Platelet counts initially fell and later returned to admission levels. Rising levels of plasma fibrinogen were recorded. The kaolin cephalin clotting time was shorter than its control in twenty-one patients. Eighteen patients had elevated fibrinogen degradation products and fourteen had a positive ethanol gelation test. It is suggested that by taking into account the results in series of individual patients a degree of intravascular coagulation may be a common feature of acute pancreatitis. In one patient (presented in detail) strong evidence for disseminated intravascular coagulation was found PMID:887529

  2. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2001-02-01

    This is the fifth quarterly report on a new study to develop a ceramic membrane/metal joint. Results of wetting experiments on commercially available Nickel based brazing alloys on perovskite surfaces are described. Additionally, experimental and numerical investigations on the strength of concentric ceramic/metal joints are presented.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Follow up study of haematological effects in workers exposed to 2-methoxyethanol

    PubMed Central

    Shih, T; Hsieh, A; Chen, Y; Liao, G; Chen, C; Chou, J; Liou, S

    2003-01-01

    Aims: To examine the association between 2-methoxyethanol (2-ME) exposure and haematological effects, as well as the recovery from these haematological effects with continuous reduction in exposure to 2-ME. Methods: Twenty nine exposed and 90 non-exposed workers were recruited. Haematological parameters, eight hour full shift personal exposure to 2-ME, and urinary 2-methoxyacetic acid (MAA) were repeatedly measured in three consecutive surveys within six months. Results: Results of haematological examination in the first exposure survey showed that haemoglobin, packed cell volume, and red blood cell count in the male exposed workers were significantly lower than those in the comparison workers. The frequency of anaemia in the exposed group (42%) was significantly higher than that in the comparison group (3%). The haematological effects were significantly associated with the urinary MAA of exposed workers. The haematological effects had returned to normal in the first follow up survey 2.5 months later, when a reduction in 2-ME exposure was noted. Haematological results of the second follow up examination six months later remained normal. The mean airborne exposure of 2-ME in the three surveys dropped from 35.7 to 2.65, then to 0.55 ppm. The mean urinary MAA of exposed workers in the three surveys was reduced from 57.7 to 24.6, then to 13.5 mg/g creatinine (n = 29). The reduction in exposure through both inhalation and potential dermal contact with 2-ME might account for the haematological recovery. Conclusion: 2-ME is a haematological toxin which leads to anaemia in exposed workers. However, the toxic haematological effects of 2-ME persist for only a short period of time after cessation or reduction of exposure. PMID:12554841

  9. Screening haematology patients for carbapenem-resistant Klebsiella pneumoniae

    PubMed Central

    Kilgour, Elizabeth; Dunn, Caroline; Thomas, Linda; Fox, Richard; Mitchell, Lindsay; Paterson, Pamela

    2013-01-01

    Following a cluster of haematology patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) septicaemia, we initiated screening for rectal carriage of CRKP and multidrug-resistant K. pneumoniae (MDRKP) in this patient group. Haematology inpatients submit a rectal swab once weekly. When plated onto chromogenic Brilliance™ UTI Agar (Oxoid), and incubated overnight with a 10 µg ertapenem disc (Oxoid), K. pneumoniae is identified and semi-automated antibiotic susceptibility testing is performed using the Vitek 2 analyser (Biomerieux). When no zone of inhibition occurs, immediate intervention through patient isolation and enhanced environmental cleaning can be instigated to control further spread while empirical antibiotic prescribing is adapted to take account of identified resistances. Over 2 years, six patients with CRKP and 20 patients with MDRKP were identified. These isolates were resistant to first-line empirical treatment choices for neutropenic sepsis and presented a clinical risk of treatment failure for sepsis post cytotoxic chemotherapy. We describe how this rectal screening methodology was developed and how the results influenced appropriate antibiotic prescribing, patient placement in single rooms and the cleaning of the ward environment to prevent person-to-person transmission of MDRKP and CRKP.

  10. 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.

  11. 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.

  12. 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.

  13. Development of a Minimal-Bulk Oxygen Delivery Product to Enhance Survival During Hemorrhagic Shock/Studies Regarding the Use of Perfluorocarbon- Derived Intravascular Microbubbles from Oxygen Transport

    DTIC Science & Technology

    2009-07-01

    TREATED PIGS A few minu tes after th e Hextend infusion was initiated, th e arterial pr essures started to incr ease gradually as demonstrated in Figure...Until the end of treatment both panels displays SAP (systolic arterial pressure) and DAP (diastolic arterial pr essure ) as mean ± SE, after...toxicity, high pressu re nervous syndrome, work to lerance at pr essure , hyperbaric oxygen treatment for decompression sickness and clinical use

  14. 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.

  15. Amelioration of hypoxia-induced striatal 5-HT(2A) receptor, 5-HT transporter and HIF1 alterations by glucose, oxygen and epinephrine in neonatal rats.

    PubMed

    Anju, T R; Paulose, C S

    2011-09-20

    Alterations in neurotransmitters and its receptors expression induce brain injury during neonatal hypoxic insult. Molecular processes regulating the serotonergic receptors play an important role in the control of respiration under hypoxic insult. The present study focused on the serotonergic regulation of neonatal hypoxia and its resuscitation methods. Receptor binding assays and gene expression studies were done to evaluate the changes in 5HT(2A) receptors and its transporter in the corpus striatum of hypoxic neonatal rats and hypoxic rats resuscitated with glucose, oxygen and epinephrine. Total 5HT and 5HT(2A) receptor number was increased in hypoxic neonates along with an up regulation of 5HT(2A) receptor and 5HT transporter gene. The enhanced striatal 5HT(2A) receptors modulate the ventilatory response to hypoxia. Immediate glucose resuscitation was found to ameliorate the receptor and transporter alterations. Hypoxia induced ATP depletion mediated reduction in blood glucose levels can be encountered by glucose administration and oxygenation helps in overcoming the anaerobic condition. The adverse effect of immediate oxygenation and epinephrine supplementation was also reported. This has immense clinical significance in establishing a proper resuscitation for the management of neonatal hypoxia.

  16. ReaxFF reactive force field for solid oxide fuel cell systems with application to oxygen ion transport in yttria-stabilized zirconia.

    PubMed

    van Duin, Adri C T; Merinov, Boris V; Jang, Seung Soon; Goddard, William A

    2008-04-10

    We present the ReaxFF reactive force field developed to provide a first-principles-based description of oxygen ion transport through yttria-stabilized zirconia (YSZ) solid oxide fuel cell (SOFC) membranes. All parameters for ReaxFF were optimized to reproduce quantum mechanical (QM) calculations on relevant condensed phase and cluster systems. We validated the use of ReaxFF for fuel cell applications by using it in molecular dynamics (MD) simulations to predict the oxygen ion diffusion coefficient in yttria-stabilized zirconia as a function of temperature. These values are in excellent agreement with experimental results, setting the stage for the use of ReaxFF to model the transport of oxygen ions through the YSZ electrolyte for SOFC. Because ReaxFF descriptions are already available for some catalysts (e.g., Ni and Pt) and under development for other high-temperature catalysts, we can now consider fully first-principles-based simulations of the critical functions in SOFC, enabling the possibility of in silico optimization of these materials. That is, we can now consider using theory and simulation to examine the effect of materials modifications on both the catalysts and transport processes in SOFC.

  17. Ionotropic glutamate receptors and glutamate transporters are involved in necrotic neuronal cell death induced by oxygen-glucose deprivation of hippocampal slice cultures.

    PubMed

    Bonde, C; Noraberg, J; Noer, H; Zimmer, J

    2005-01-01

    Organotypic hippocampal slice cultures represent a feasible model for studies of cerebral ischemia and the role of ionotropic glutamate receptors in oxygen-glucose deprivation-induced neurodegeneration. New results and a review of existing data are presented in the first part of this paper. The role of glutamate transporters, with special reference to recent results on inhibition of glutamate transporters under normal and energy-failure (ischemia-like) conditions is reviewed in the last part of the paper. The experimental work is based on hippocampal slice cultures derived from 7 day old rats and grown for about 3 weeks. In such cultures we investigated the subfield neuronal susceptibility to oxygen-glucose deprivation, the type of induced cell death and the involvement of ionotropic glutamate receptors. Hippocampal slice cultures were also used in our studies on glutamate transporters reviewed in the last part of this paper. Neurodegeneration was monitored and/or shown by cellular uptake of propidium iodide, loss of immunocytochemical staining for microtubule-associated protein 2 and staining with Fluoro-Jade B. To distinguish between necrotic vs. apoptotic neuronal cell death we used immunocytochemical staining for active caspase-3 (apoptosis indicator) and Hoechst 33342 staining of nuclear chromatin. Our experimental studies on oxygen-glucose deprivation confirmed that CA1 pyramidal cells were the most susceptible to this ischemia-like condition. Judged by propidium iodide uptake, a selective CA1 lesion, with only minor affection on CA3, occurred in cultures exposed to oxygen-glucose deprivation for 30 min. Nuclear chromatin staining by Hoechst 33342 and staining for active caspase-3 showed that oxygen-glucose deprivation induced necrotic cell death only. Addition of 10 microM of the N-methyl-D-aspartate glutamate receptor antagonist MK-801, and 20 microM of the non-N-methyl-D-aspartate glutamate receptor antagonist 2,3-dihyroxy-6-nitro-7-sulfamoyl

  18. Acclimatory responses of the Daphnia pulex proteome to environmental changes. I. Chronic exposure to hypoxia affects the oxygen transport system and carbohydrate metabolism

    PubMed Central

    Zeis, Bettina; Lamkemeyer, Tobias; Paul, Rüdiger J; Nunes, Frank; Schwerin, Susanne; Koch, Marita; Schütz, Wolfgang; Madlung, Johannes; Fladerer, Claudia; Pirow, Ralph

    2009-01-01

    Background Freshwater planktonic crustaceans of the genus Daphnia show a remarkable plasticity to cope with environmental changes in oxygen concentration and temperature. One of the key proteins of adaptive gene control in Daphnia pulex under hypoxia is hemoglobin (Hb), which increases in hemolymph concentration by an order of magnitude and shows an enhanced oxygen affinity due to changes in subunit composition. To explore the full spectrum of adaptive protein expression in response to low-oxygen conditions, two-dimensional gel electrophoresis and mass spectrometry were used to analyze the proteome composition of animals acclimated to normoxia (oxygen partial pressure [Po2]: 20 kPa) and hypoxia (Po2: 3 kPa), respectively. Results The comparative proteome analysis showed an up-regulation of more than 50 protein spots under hypoxia. Identification of a major share of these spots revealed acclimatory changes for Hb, glycolytic enzymes (enolase), and enzymes involved in the degradation of storage and structural carbohydrates (e.g. cellubiohydrolase). Proteolytic enzymes remained constitutively expressed on a high level. Conclusion Acclimatory adjustments of the D. pulex proteome to hypoxia included a strong induction of Hb and carbohydrate-degrading enzymes. The scenario of adaptive protein expression under environmental hypoxia can be interpreted as a process to improve oxygen transport and carbohydrate provision for the maintenance of ATP production, even during short episodes of tissue hypoxia requiring support from anaerobic metabolism. PMID:19383146

  19. TRANSPORT

    EPA Science Inventory

    Presentation outline: transport principles, effective solubility; gasoline composition; and field examples (plume diving).
    Presentation conclusions: MTBE transport follows from - phyiscal and chemical properties and hydrology. Field examples show: MTBE plumes > benzene plu...

  20. 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.

  1. [Managing of platelet transfusion refractoriness of haematological malignancies. Experience IPC-EFSAM].

    PubMed

    Dettori, I; Ladaique, P

    2014-11-01

    The platelet refractoriness is a complication of transfusion treatments potentially dramatic in onco-haematology. Chemo-treatment of haematological malignancies or packs of allogeneic bone marrow transplants require iterative platelet transfusion requirements. The discovery of a platelet refractoriness along with its support should be the most reactive as possible but also adapted to the cause. In the case of allo-immunization, it may be expected. The purpose of this presentation is to recall the different etiologies and perform a feedback on the support transfusion platelet of onco-haematology adult patients at Institut Paoli-Calmettes (IPC) in partnership with the EFSAM.

  2. Recent advances in T-cell immunotherapy for haematological malignancies.

    PubMed

    Rouce, Rayne H; Sharma, Sandhya; Huynh, Mai; Heslop, Helen E

    2017-03-01

    In vitro discoveries have paved the way for bench-to-bedside translation in adoptive T cell immunotherapy, resulting in remarkable clinical responses in a variety of haematological malignancies. Adoptively transferred T cells genetically modified to express CD19 CARs have shown great promise, although many unanswered questions regarding how to optimize T-cell therapies for both safety and efficacy remain. Similarly, T cells that recognize viral or tumour antigens though their native receptors have produced encouraging clinical responses. Honing manufacturing processes will increase the availability of T-cell products, while combining T-cell therapies has the ability to increase complete response rates. Lastly, innovative mechanisms to control these therapies may improve safety profiles while genome editing offers the prospect of modulating T-cell function. This review will focus on recent advances in T-cell immunotherapy, highlighting both clinical and pre-clinical advances, as well as exploring what the future holds.

  3. Pathogenetic determinants in Kawasaki disease: the haematological point of view.

    PubMed

    Del Principe, Domenico; Pietraforte, Donatella; Gambardella, Lucrezia; Marchesi, Alessandra; Tarissi de Jacobis, Isabella; Villani, Alberto; Malorni, Walter; Straface, Elisabetta

    2017-04-01

    Kawasaki disease is a multisystemic vasculitis that can result in coronary artery lesions. It predominantly affects young children and is characterized by prolonged fever, diffuse mucosal inflammation, indurative oedema of the hands and feet, a polymorphous skin rash and non-suppurative lymphadenopathy. Coronary artery involvement is the most important complication of Kawasaki disease and may cause significant coronary stenosis resulting in ischemic heart disease. The introduction of intravenous immunoglobulin decreases the incidence of coronary artery lesions to less than 5%. The etiopathogenesis of this disease remains unclear. Several lines of evidence suggest that an interplay between a microbial infection and a genetic predisposition could take place in the development of the disease. In this review, we summarize the state of the art of pathogenetic mechanisms of Kawasaki disease underscoring the relevance of haematological features as a novel field of investigation.

  4. Evaluation of haematological, biochemical and histopathological parameters of transgenic rabbits.

    PubMed

    Jurcik, R; Suvegova, K; Hanusova, E; Massanyi, P; Ryban, L; Chrenek, P

    2007-11-01

    The aim of our study was to compare the hFVIII mRNA expression in different organs, pathological changes and selected haematological and biochemical blood parameters between transgenic and non-transgenic rabbits from F3 generation. Selected physiological parameters of 3- to 4-month-old transgenic rabbits from F3 generation carrying human factor VIII gene (hFVIII) were analysed and compared with those of non-transgenic ones. Before slaughtering, the blood for haematological and biochemical analysis was taken from the central ear artery. Pathological and histological examination of vital organs and RT-PCR analysis of several tissue organs of transgenic and non-transgenic animals were performed after slaughtering. Except for the mammary gland tissue, slight hfVIII mRNA expression in the spleen, lung and brain and none expression in the liver, kidney, skeletal muscle and heart of rabbits were recorded. pathological examination of vital organs showed some pathological changes in both transgenic and non-transgenic rabbits which were confirmed by histological qualitative evaluations. Statistically significant lower values of blood haemoglobin in blood of transgenic (11.86+/-0.86) animals compared with non-transgenic (12.41+/-1.02, P<0.05) ones and lower parameters of HCT (39.22+/-2.44 versus 40.89+/-2.26, P<0.01) in blood of transgenic rabbits were observed. Parameters of WBC, RBC and PLT showed no significant differences between the analysed groups. All biochemical serum parameters of transgenic rabbits were higher in comparison with non-transgenic ones. Significant differences were found in the concentration of the urea, AST and GMT between transgenic and non-transgenic animals (P<0.001) and in the total protein content, the difference was significant at P<0.05. In conclusion, our results showed that no considerable impact on the general health was found in transgenic rabbits.

  5. Haematological cancers: improving outcomes. A summary of updated NICE service guidance in relation to Specialist Integrated Haematological Malignancy Diagnostic Services (SIHMDS).

    PubMed

    Snowden, John A; O'Connell, Susan; Hawkins, James; Dalley, Chris; Jack, Andrew; Mannari, Deepak; McNamara, Chris; Scott, Mike; Shenton, Geoff; Soilleux, Elizabeth; Macbeth, Fergus

    2017-04-07

    Haematological malignancies are a diverse group of cancers that affect the blood, bone marrow and lymphatic systems. Laboratory diagnosis of haematological malignancies is dependent on combining several technologies, including morphology, immunophenotyping, cytogenetics and molecular genetics correlated clinical details and classification according to the current WHO guidelines. The concept of the Specialised Integrated Haematological Malignancy Diagnostic Services (SIHMDS) has evolved since the UK National Institute for Health and Care Excellence (NICE) Improving Outcomes Guidance (IOG) in 2003 and subsequently various models of delivery have been established. As part of the 2016 update to the NICE IOG, these models were systematically evaluated and recommendations produced to form the basis for quality standards for future development of SIHMDS. We provide a summary of the systematic review and recommendations. Although the recommendations pertain to the UK National Health Service (NHS), they have relevance to the modern delivery of diagnostic services internationally.

  6. Oxidation of sitosterol and transport of its 7-oxygenated products from different tissues in humans and ApoE knockout mice.

    PubMed

    Schött, Hans-Frieder; Baumgartner, Sabine; Husche, Constanze; Luister, Alexandra; Friedrichs, Silvia; Miller, Charlotte M; McCarthy, Florence O; Plat, Jogchum; Laufs, Ulrich; Weingärtner, Oliver; Lütjohann, Dieter

    2016-04-27

    The most common phytosterols in the human diet are sitosterol and campesterol, which originate exclusively from plant derived food. These phytosterols are taken up by NPC1L1 transport from the intestine into the enterocytes together with cholesterol and other xenosterols. Phytosterols are selectively pumped back from the enterocytes into the intestinal lumen and on the liver site from hepatocytes into bile by heterodimeric ABCG5/G8 transporters. Like cholesterol, both phytosterols are prone to ring and side chain oxidation. It could be shown that oxyphytosterols, found in atherosclerotic tissue, are most likely of in situ oxidation (Schött et al.; Biochem. Biophys. Res. Commun. 2014 Apr 11;446(3):805-10). However, up to now, the entire mechanism of phytosterol oxidation is not clearly understood. Here, we provide further information about the oxidation of sitosterol and the transport of its oxidation products out of tissue. Our survey includes data of 104 severe aortic stenosis patients that underwent an elective aortic valve cusp replacement. We studied their phytosterol concentrations, as well as absolute and substrate corrected oxyphytosterol levels in plasma and valve cusp tissue. In addition, we also examined phytosterol and oxyphytosterol concentrations in plasma and tissues (from brain and liver) of 10 male ApoE knockout mice. The ratio of 7-oxygenated-sitosterol-to-sitosterol exceeds the ratio for 7-oxygenated-campesterol-to-campesterol in plasma and tissue of both humans and mice. This finding indicates that sitosterol is oxidized to a higher amount than campesterol and that a selective oxidative mechanism might exist which can differentiate between certain phytosterols. Secondly, the concentrations of oxyphytosterols found in plasma and tissue support the idea that oxysitosterols are preferably transported out of individual tissues. Selective oxidation of sitosterol and preferred transport of sitosterol oxidation products out of tissue seem to be a

  7. Haematology in the Republic of Macedonia: present situation and brief history.

    PubMed

    Panovska-Stavridis, I; Cevreska, L

    2013-01-01

    The development of clinical haematology in Macedonia has taken place over the past nine decades. The greatest expansion of its development took place in the second half of the 20th century. The oficial start of clinical haematology dates from 1956, when the Department of Haematology was founded within the framework of the Internal Medicine Clinic in Skopje. In the beginning, haematology represented a form of virtual sub-specialty, but its expansion was so progressive and rapid that it reached the highest peaks of Yugoslav haematology in those times. The period from 1968 to 1979 was a period of integral development of haematology and blood-transfusion science in Macedonia. Nowadays, the autonomous Public Health Institution, the University Hematology Clinic, is a unique healthcare, educational and scientific establishment in the Republic of Macedonia in its field of work. The diagnostics algorithm comprises cyto-morphologic and cyto-chemical analysis, through immunologic characterization with the assistance of a flow cytometer, to sophisticated molecular analysis for detecting genetic abnormalities. The therapeutic approach is based upon modern poly-haemotherapeutic protocols, application of monoclonal antibodies, immuno-modulatory agents, molecular target therapy and the use of alogeneic and autologous transplantation of fresh bone-marrow and frozen haemopoietic stem-cells. The current motto of the Haematology Clinic is: always help those who seek help, provide precise and early diagnostics, and apply all up-to-date therapeutic strategies, scientific research, continual education and day-to-day implementation of the latest achievements in the field of haematology in daily practice.

  8. Normal and clinical haematology of greater and lesser flamingos (Phoenicopterus roseus and Phoeniconaias minor).

    PubMed

    Hawkey, C M; Hart, M G; Samour, H J

    1985-10-01

    Normal haematological reference values were obtained for Greater and Lesser flamingos (Phoenicopterus roseus, Phoeniconaias minor). Statistically significant differences in the total white cell count and the absolute heterophil count were found in the two species. The reference values were used to identify abnormalities in the blood of five sick birds. Three of these were anaemic, all showed red cell hypochromia and four had heterophilia. The findings suggested that haematological testing is of potential diagnostic value in the species.

  9. 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

  10. 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.

  11. Increased blood oxygen affinity during digestion in the snake Python molurus.

    PubMed

    Overgaard, Johannes; Wang, Tobias

    2002-11-01

    Many snakes exhibit large increases in metabolic rate during digestion that place extensive demands on efficient oxygen transport. In the present study, we describe blood oxygen affinity following three weeks of fasting and 48 h after feeding in the Burmese python (Python molurus). We also report simultaneous measurements of arterial blood gases and haematological parameters. Arterial blood was obtained from chronically implanted catheters, and blood oxygen-dissociation curves were constructed from oxygen content measurements at known oxygen partial pressure (P(O(2))) values at 2% and 5% CO(2). Arterial pH remained constant at approximately 7.6 after feeding, but digestion was associated with an approximately 6 mmol l(-1) increase in [HCO(3)(-)], while CO(2) partial pressure (P(CO(2))) increased from 2.21+/-0.13 kPa in fasted animals to 2.89+/-0.17 kPa at 48 h after feeding. Blood oxygen affinity in vivo was predicted on the basis of pH in vivo and the blood oxygen-dissociation curves obtained in vitro. The blood oxygen affinity in vivo increased during digestion, with P(50) values decreasing from 4.58+/-0.11 kPa to 3.53+/-0.24 kPa. This increase was associated with a significant decrease in the red blood cell [NTP]/[Hb(4)] ratio (relationship between the concentrations of organic phosphates and total haemoglobin) and a significant decrease in mean cellular haemoglobin content, which is indicative of swelling of the red blood cells. Our data for blood oxygen affinity and arterial oxygen levels, together with previously published values of oxygen uptake and blood flows, allow for a quantitative evaluation of oxygen transport during digestion. This analysis shows that a large part of the increased metabolism during digestion is supported by an increased venous extraction, while arterial P(O(2)) (Pa(O(2))) and haemoglobin saturation do not vary with digestive status. Thus, we predict that venous P(O(2)) (Pv(O(2))) is reduced from a fasting value of 5.2 kPa to 1.6 k

  12. Electrical Transport Properties of Epitaxial and Granular Oriented Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) Thin Films

    NASA Astrophysics Data System (ADS)

    Jones, Edwin Clay

    1992-01-01

    Strong correlations between the Hall coefficient R_{H}, the transition temperature T_{c}, and the critical current density J_{c} were established in a series of epitaxial YBa_2Cu_3O_ {7-delta} thin films as a function of oxygen deficiency delta. Steady increases in R_{H} with delta suggests that dexoygenation reduces the density of states which, according to BCS theory, should lead to corresponding decreases in T_ {c}. In contrast, two well known plateaus occurring at 90K and 60K were observed in T _{c} vs. delta . Others have ascribed these plateaus to either electronic phenomena or oxygen clustering. We find that in the 90K plateau, the critical current density J _{c}(delta ,H = 0) decreased with delta and extrapolates toward zero at the edge of the plateau, while the relative field dependence of J_ {c}(delta,H) is independent of delta. Furthermore, a fluctuation analysis of the resistive transitions indicates a constant upper critical field B_{ c2}(0) = 110T across this plateau. These observations suggest that the oxygen clustering/percolation scenario occurs on the 90K plateau. Moreover, computer simulations showed this oxygen clustering/percolation picture to be a plausible explanation for the occasional observation of a sign reversal of R _{H} near T _{c}. For large oxygen deficiencies (delta > 0.5) and for the granular oriented YBa_2Cu_3O _{7-delta} thin films, rapid decreases in J_{c} with applied field were observed which is reminiscent of the conventional granular alloys. In addition, the self -field critical current densities J_{c} behaved as SNS weak link systems in a Josephson mixed state. In sum, due to the short coherence length xi in these materials, many properties formerly believed to be "intrinsic" in nature are apparently "extrinsic" in nature.

  13. Characteristics of invasive aspergillosis in neutropenic haematology patients (Sousse, Tunisia).

    PubMed

    Gheith, Soukeina; Saghrouni, Fatma; Bannour, Wadiaa; Ben Youssef, Yosra; Khelif, Abderrahim; Normand, Anne-Cécile; Ben Said, Moncef; Piarroux, Renaud; Njah, Mansour; Ranque, Stéphane

    2014-06-01

    Although scarce, available data suggest that the epidemiology of invasive aspergillosis (IA) in North Africa differs from northern countries, where more than 80 % is caused by Aspergillus fumigatus. This study aimed at describing the epidemiology of IA in the region of Sousse, Tunisia, and at assessing the usefulness of the available diagnostic tools. For 2 years, clinical and mycological data were prospectively collected from 175 neutropenia episodes of 91 patients hospitalised in the haematology department at the Farhat Hached hospital in Sousse (Tunisia). Screening for galactomannan antigen was positive in 40 % of neutropenia episodes; Aspergillus PCR was positive in 42 % of the tested sera. Nine patients were classified as probable and two as possible IA according to the EORTC/MSG criteria. Twelve patients who prematurely died, had no CT scan and could not be classified. Fifty-six Aspergillus spp. were isolated in 53 (6.5 %) sputa collected from 35 (20 %) patients. The following species were identified with MALDI-TOF mass spectrometry and DNA sequencing: A. niger, 35 %; A. flavus, 38 %; A. tubingensis, 19 %; A. fumigatus, 4 %; A. westerdijkiae, 2 % and A. ochraceus, 2 %. Our findings highlight the epidemiological features of IA in Tunisia, which is characterised by the predominance of Aspergillus spp. from sections Nigri and Flavi.

  14. Guidelines for point-of-care testing: haematology.

    PubMed

    Briggs, Carol; Guthrie, David; Hyde, Keith; Mackie, Ian; Parker, Norman; Popek, Mary; Porter, Neil; Stephens, Clare

    2008-09-01

    This guideline provides a framework for the arrangement of point-of-care testing (POCT) services, previously known as near patient testing (patient self-testing not covered). POCT is defined as any analytical test performed outside the laboratory. Primary users are often non-laboratory healthcare workers. The guidance applies to units within hospitals as well as general practioner surgeries, community clinics and pharmacies. The head of the haematology laboratory or a point of care coordinator must take responsibility for all aspects of the POCT service, including quality and training. Depending on the size and nature of the POCT practice, a local POCT manager may also be required. Equipment selected should have received a successful independent performance evaluation. If an independent evaluation has not been performed the purchaser should assess the device according to the protocol in this document. POCT devices should generate results that are comparable to those of the local laboratory. An accredited external quality assessment programme and internal quality control system must be established. Manufacturers promoting POCT devices designed for non-laboratory sites, e.g. pharmacies, should undertake training and annual competency assessment, perhaps using a web-based system. A diagram to illustrate the stages for the implementation of a POCT service is illustrated.

  15. 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 %).

  16. Guidelines on Vaccinations in Paediatric Haematology and Oncology Patients

    PubMed Central

    Cesaro, Simone; Giacchino, Mareva; Fioredda, Francesca; Barone, Angelica; Battisti, Laura; Bezzio, Stefania; Frenos, Stefano; De Santis, Raffaella; Livadiotti, Susanna; Marinello, Serena; Zanazzo, Andrea Giulio; Caselli, Désirée

    2014-01-01

    Objective. Vaccinations are the most important tool to prevent infectious diseases. Chemotherapy-induced immune depression may impact the efficacy of vaccinations in children. Patients and Methods. A panel of experts of the supportive care working group of the Italian Association Paediatric Haematology Oncology (AIEOP) addressed this issue by guidelines on vaccinations in paediatric cancer patients. The literature published between 1980 and 2013 was reviewed. Results and Conclusion. During intensive chemotherapy, vaccination turned out to be effective for hepatitis A and B, whilst vaccinations with toxoid, protein subunits, or bacterial antigens should be postponed to the less intensive phases, to achieve an adequate immune response. Apart from varicella, the administration of live-attenuated-virus vaccines is not recommended during this phase. Family members should remain on recommended vaccination schedules, including toxoid, inactivated vaccine (also poliomyelitis), and live-attenuated vaccines (varicella, measles, mumps, and rubella). By the time of completion of chemotherapy, insufficient serum antibody levels for vaccine-preventable diseases have been reported, while immunological memory appears to be preserved. Once immunological recovery is completed, usually after 6 months, response to booster or vaccination is generally good and allows patients to be protected and also to contribute to herd immunity. PMID:24868544

  17. Guide-lines for near patient testing: haematology.

    PubMed

    1995-12-01

    These guide-lines provide a framework for the local arrangement of near patient testing (NPT) services for haematology tests. The guidance may be applied to medical and surgical units within hospitals (e.g. ITU, renal dialysis units, casualty) as well as general practitioners' surgeries, for blood counts and coagulation testing. The professional head of the central laboratory must take responsibility for all aspects of the NPT service, although there should be full discussion with the clinical departments involved and joint ownership of the results. NPT operators must be trained and accredited by the central laboratory. Equipment selected should normally have received a satisfactory evaluation report from the Medical Devices Agency (MDA), and should generate results that are comparable with those of the central laboratory. If a full MDA operation evaluation has not been performed, the purchaser should perform a local assessment according to the protocol in this document. The suitability of the equipment, imprecision, and comparability must be studied. The NPT equipment must be properly maintained and calibrated, and a record of patient identity, date and time of testing, reagent lot numbers, and operator must be kept. The central laboratory must participate in a suitable external quality assessment programme (EQA), and provide systems for EQA and internal quality control (IQC) of the NPT site.

  18. Clinical haematology of the great bustard (Otis tarda).

    PubMed

    Jimenez, A; Barrera, R; Sanchez, J; Cuenca, R; Rodriguez, J; Andres, S; Mane, M C

    1991-12-01

    The haematological parameters of healthy great bustards (Otis tarda L.) have been determined. The values obtained were red cell count (3.0 x 10(12) +/- 0.2 x 10(12/)1), white cell count (33.0 x 10(9) +/- 2.6 x 10(9)/1), haematocrit value (0.51 +/- 0.01 1/1), haemoglobin (13.0 +/- 0.3 g/dl), mean corpuscular volume (178.7 +/- 12.5 fl), mean cell haemoglobin concentration (25.0 +/- 0.6 g/dl), mean corpuscular haemoglobin (42.5 +/- 3.2 pg), differential white cell count: heterophils (22.5 x 10(9) +/- 0.7 x 10(9)/1), lymphocytes (6.0 x 10(9)+/-0.7 x 10(9)/1), eosinophils (2.7 x 10(9) +/- 0.3 x 10(9)/1) and monocytes (1.8 x 10(9)+/-0.2 x 10(9)/1).

  19. GDNF pre-treatment aggravates neuronal cell loss in oxygen-glucose deprived hippocampal slice cultures: a possible effect of glutamate transporter up-regulation.

    PubMed

    Bonde, C; Sarup, A; Schousboe, A; Gegelashvili, G; Noraberg, J; Zimmer, J

    2003-01-01

    Besides its neurotrophic and neuroprotective effects on dopaminergic neurons and spinal motoneurons, glial cell line-derived neurotrophic factor (GDNF) has potent neuroprotective effects in cerebral ischemia. The protective effect has so far been related to reduced activation of N-methyl-D-aspartate receptors (NMDAr). This study tested the effects of GDNF on glutamate transporter expression, with the hypothesis that modulation of glutamate transporter activity would affect the outcome of cerebral ischemia. Organotypic hippocampal slice cultures, derived from 1-week-old rats, were treated with 100 ng/ml GDNF for either 2 or 5 days, followed by Western blot analysis of NMDAr subunit 1 (NR1) and two glutamate transporter subtypes, GLAST and GLT-1. After 5-day exposure to GDNF, expression of GLAST and GLT-1 was up-regulated to 169 and 181% of control values, respectively, whereas NR1 was down-regulated to 64% of control. However, despite these changes that potentially would support neuronal resistance to excitotoxicity, the long-term treatment with GDNF was found to aggravate the neuronal damage induced by oxygen-glucose deprivation (OGD). The increased cell death, assessed by propidium iodide (PI) uptake, occurred not only among the most susceptible CA1 pyramidal cells, but also in CA3 and fascia dentata. Given that glutamate transporters are able to release glutamate by reversed action during energy failure, it is suggested that the observed increase in OGD-induced cell death in the GDNF-pretreated cultures was caused by the build-up of excitotoxic concentrations of extracellular glutamate released through the glutamate transporters, which were up-regulated by GDNF. Although the extent and consequences of glutamate release via reversal of GLAST and GLT-1 transporters seem to vary in different energy failure models, the present findings should be taken into account in clinical trials of GDNF.

  20. 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.

  1. 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.

  2. Oxygen sensing and signaling.

    PubMed

    van Dongen, Joost T; Licausi, Francesco

    2015-01-01

    Oxygen is an indispensable substrate for many biochemical reactions in plants, including energy metabolism (respiration). Despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, steep oxygen gradients occur within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability. Plants possess various responses to cope with spatial and temporal variations in oxygen availability, many of which involve metabolic adaptations to deal with energy crises induced by low oxygen. Responses are induced gradually when oxygen concentrations decrease and are rapidly reversed upon reoxygenation. A direct effect of the oxygen level can be observed in the stability, and thus activity, of various transcription factors that control the expression of hypoxia-induced genes. Additional signaling pathways are activated by the impact of oxygen deficiency on mitochondrial and chloroplast functioning. Here, we describe the molecular components of the oxygen-sensing pathway.

  3. [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.

  4. Seasonal changes in blood oxygen transport and acid-base status in the tegu lizard, Tupinambis merianae.

    PubMed

    Andrade, Denis V; Brito, Simone P; Toledo, Luís Felipe; Abe, Augusto S

    2004-05-20

    Oxygen-binding properties, blood gases, and acid-base parameters were studied in tegu lizards, Tupinambis merianae, at different seasons and temperatures. Independent of temperature and pH, blood oxygen affinity was higher in dormant lizards than in those active during the summer. Haematocrit (Hct) and hemoglobin content ([Hb]) were greater in active lizards resulting in a higher oxygen-carrying capacity. Nucleoside triphosphate content ([NTP]) was reduced during dormancy, but the ratio between [NTP] and [Hb] remained unchanged. Dormancy was accompanied by an increase in plasma bicarbonate ([HCO-(3)]pl) and an elevation of arterial CO2 partial pressure (PaCO2) and CO2 content in the plasma (CplCO2). These changes in acid-base parameters persist over a broad range of body temperatures. In vivo, arterial O2 partial pressure (PaO2) and O2 content (CaO2) were not affected by season and tended to increase with temperature. Arterial pH (pHa) of dormant animals is reduced compared to active lizards at body temperatures below 15 degrees C, while no significant difference was noticed at higher temperatures.

  5. Guideline: the laboratory diagnosis of malaria. General Haematology Task Force of the British Committee for Standards in Haematology.

    PubMed

    Bailey, J Wendi; Williams, John; Bain, Barbara J; Parker-Williams, John; Chiodini, Peter L

    2013-12-01

    UK National External Quality Assessment Service surveys indicate continuing problems in malaria diagnosis: inaccurate calculation of parasitaemia or failure to estimate it altogether, difficulty distinguishing Plasmodium vivax from P. ovale, reporting malaria parasites when none were present and misidentification of P. falciparum as another species still occur. Therefore, the British Committee for Standards in Haematology Guidelines for the Laboratory Diagnosis of Malaria have been revised. They are intended for use in the UK but may also prove useful in other non-endemic areas. Routine use of thick and thin films is advised for malaria diagnosis. Thick films should be stained using Giemsa or Field stain. Thin films should be stained with Giemsa stain or Leishman stain. Thick films should be examined by two observers, each viewing a minimum of 200 high power fields. If thick films are positive, the species should be determined by examination of a thin film. In the case of P. falciparum or P. knowlesi infection, the percentage of parasitized cells or the number of parasites per microlitre (/μl) should be estimated and reported. Rapid diagnostic tests (RDTs) for malarial antigen cannot replace microscopy but are indicated as a supplementary test when malaria diagnosis is performed by relatively inexperienced staff. Malaria RDTs are negative in babesiosis.

  6. First experience with the deltastream® DP3 in venovenous extracorporeal membrane oxygenation and air-supported inter-hospital transport

    PubMed Central

    Lunz, Dirk; Philipp, Alois; Judemann, Katrin; Amann, Matthias; Foltan, Maik; Schmid, Christof; Graf, Bernhard; Zausig, York A.

    2013-01-01

    OBJECTIVES Based on continuous technical innovations and recent research, extracorporeal membrane oxygenation (ECMO) has become a promising tool in the treatment of patients with acute (cardio)pulmonary failure. Nevertheless, any extracorporeal technique requires a high degree of experience and knowledge, so that a restriction to specialized centres seems to be reasonable. As a consequence of this demand, the need for inter-hospital transfer of patients with severely impaired (cardio)pulmonary function is rising. Unfortunately, most of the ECMO devices used in the clinical setting are not suitable for inter-hospital transport because of their size, weight or complexity. In this article, we describe our first experiences with the airborne transport of 6 patients on a new portable, miniaturized and lightweight extracorporeal circulation system, the Medos deltastream® DP3. METHODS Six patients suffering acute respiratory failure were taken on venovenous ECMO (DP3) out-of-centre and transferred to the University Medical Center Regensburg by helicopter. All cardiorespiratory-relevant parameters of the patients and the technical functioning of the device were continuously monitored and documented. RESULTS Implantation of the device and air-supported transport were performed without any technical complications. The patients were transported from a distance of 66–178 km, requiring a time of 40–120 min. With the help of the new deltastream® DP3 ECMO device, a prompt stabilization of the cardiopulmonary function could be achieved in all patients. One patient was under ongoing cardiopulmonary resuscitation by the time our ECMO team arrived at the peripheral hospital and died shortly after arrival in the central emergency ward. CONCLUSIONS Our experience shows that the deltastream® DP3 is an absolutely reliable and safe ECMO device that could gain growing importance in the field of airborne transportation of patients on ECMO due to its unsophisticated, miniaturized and

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Role of Oxygen Functionalities in Graphene Oxide Architectural Laminates (GOAL) Sub-nanometer-spacing and Water Transport.

    PubMed

    Amadei, Carlo Alberto; Montessori, Andrea; Kadow, Julian P; Succi, Sauro; Vecitis, Chad David

    2017-03-23

    Active research in nanotechnology contemplates the use of nanomaterials for environmental engineering applications. However, a primary challenge is understanding the effects of nanomaterial properties on industrial device performance and translating unique nanoscale properties to the macroscale. One emerging example is graphene oxide (GO) membranes for separation processes. Thus, here we investigate how individual GO properties, in particular the GO chemistry, can impact GO membrane characteristics and water permeability. GO chemistry and morphology were controlled with easy-to-implement photo-reduction and sonication techniques and were quantitatively correlated offering a valuable tool to speed up characterization. Chemical GO modification allows for fine control of GO oxidation state enabling control of a GO architectural laminate (GOAL) spacing and permeability. Water permeability was measured for eight GOAL characterized by different GOAL chemistry and morphology, and indicate that GOAL nanochannel height dictates water transport. The experimental outputs were corroborated with mesoscale water transport simulations of relatively large domains (>1000s nm2) and indicate a no-slip Darcy-like behavior inside the GOAL nanochannels. The experimental and simulation evidence presented in this study helps create a clearer picture of water transport in GO and can be used to rationally design more effective and efficient GO membranes.

  14. Arsenic antisite and oxygen incorporation trends in GaAs grown by water-mediated close-spaced vapor transport

    NASA Astrophysics Data System (ADS)

    Boucher, Jason; Boettcher, Shannon

    2017-03-01

    Close-spaced vapor transport (CSVT) provides a plausible path to lower the costs of GaAs deposition as it uses only solid precursors and provides precursor utilization in principle approaching 100%. However, the use of H2O as a transport agent causes O to be incorporated in CSVT films, and O has been associated with a number of electrically active defect centers in GaAs, which decrease minority carrier lifetimes. Using deep-level transient spectroscopy, we study the effect of H2O concentration and substrate temperature on electron trap concentrations in n-type GaAs. We find that the most-prominent O-related center (ELO) typically has a much higher concentration than the center usually associated with As antisites (EL2), but that overall defect concentrations can be as low as those in films deposited by common vapor phase techniques. The trends with increasing H2O concentration suggest that ELO is most likely a defect complex with two As antisites. We also consider the optimal conditions for achieving high growth rates and low defect concentrations using CSVT. The results of this study have implications for the future CSVT growth using halide transport agents, where the ELO defect would be eliminated but EL2 might have a higher concentration.

  15. Effect of electron-transport inhibitors on the generation of reactive oxygen species by pea mitochondria during succinate oxidation.

    PubMed

    Popov, V N; Ruuge, E K; Starkov, A A

    2003-07-01

    The effect of inhibitors of the cytochrome pathway and alternative oxidase on the rate of respiration and generation of reactive oxygen species by pea mitochondria was studied. Respiration of mitochondria from pea cotyledons was inhibited by 70-80% by salicylhydroxamate (SHAM). The rate of hydrogen peroxide production by pea cotyledon mitochondria during succinate oxidation was 0.15 nmol/min per mg protein. SHAM considerably accelerated the hydrogen peroxide production. The SHAM-dependent H2O2 production was stimulated by 2 micro M antimycin A and inhibited by 5 mM KCN and 1 micro M myxothiazol. The study of the rate of O2*- generation by pea mitochondria using EPR spin traps and epinephrine oxidation showed that H2O2 accumulation can be accounted for by a significant increase in the rate of O2*- production.

  16. 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.

  17. 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.

  18. 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.

  19. [Studies on evaluation of the oxygen transport system function with multistage treadmill stress testing: comparison between normal control subjects and patients with coronary heart disease].

    PubMed

    Doba, N; Kushiro, T; Tomiyama, H; Hayashida, N; Yamashina, A; Abe, H; Hinohara, S

    1989-07-01

    The oxygen transport system (OTS) function was evaluated with multistage treadmill stress testing on 171 normal control subjects and 80 patients with coronary heart disease (CHD). After Bruce's definition, OTS function was expressed with functional aerobic impairment (FAI), left ventricular impairment (LVI) or myocardial aerobic impairment (MAI), heart rate impairment (HRI) or chronotropic reserve impairment (CRI) and peripheral circulatory impairment (PCI). All subjects were monitored on heart rate, blood pressure, electrocardiogram and endtidal O2 and CO2 before and every one minute during the symptom limited maximal stress testing. Seventy three of 80 coronary patients were subjected to the coronary arteriography and were classified into four groups; 31 with single vessel disease (SVD), 20 with double vessel disease (DVD), 15 with triple vessel disease (TVD) and 7 with A-C bypass surgery. Comparison between normal control subjects and the CHD patients with regard to the relation of age and VO2max derived from the linear regression analysis disclosed the identical age-related decrease in VO2max in both groups. The age corrected VO2max in the CHD patients, however, was 2.2 METS less than that of normal control subjects. Therefore, the level of VO2max in CHD patients was determined not only by disease, but also by ageing process itself. Comparisons among three CHD groups with regard to FAI, LVI, HRI and PCI clearly demonstrated different functional impairments paralleling to the severity of the disease process. On the other hand, the patients with A-C bypass surgery revealed almost identical functional impairment to the patients with SVD. In conclusion, these simple and noninvasive evaluations of the oxygen transport system could give us valuable informations reasonably differentiating the clinical status of the patients with CHD.

  20. Oxygen "getter" effects on microstructure and carrier transport in low temperature combustion-processed a-InXZnO (X = Ga, Sc, Y, La) transistors.

    PubMed

    Hennek, Jonathan W; Smith, Jeremy; Yan, Aiming; Kim, Myung-Gil; Zhao, Wei; Dravid, Vinayak P; Facchetti, Antonio; Marks, Tobin J

    2013-07-24

    In oxide semiconductors, such as those based on indium zinc oxide (IXZO), a strong oxygen binding metal ion ("oxygen getter"), X, functions to control O vacancies and enhance lattice formation, hence tune carrier concentration and transport properties. Here we systematically study, in the IXZO series, the role of X = Ga(3+) versus the progression X = Sc(3+) → Y(3+) → La(3+), having similar chemical characteristics but increasing ionic radii. IXZO films are prepared from solution over broad composition ranges for the first time via low-temperature combustion synthesis. The films are characterized via thermal analysis of the precursor solutions, grazing incidence angle X-ray diffraction (GIAXRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM) with high angle annular dark field (HAADF) imaging. Excellent thin-film transistor (TFT) performance is achieved for all X, with optimal compositions after 300 °C processing exhibiting electron mobilities of 5.4, 2.6, 2.4, and 1.8 cm(2) V(-1) s(-1) for Ga(3+), Sc(3+), Y(3+), and La(3+), respectively, and with I(on)/I(off) = 10(7)-10(8). Analysis of the IXZO TFT positive bias stress response shows X = Ga(3+) to be superior with mobilities (μ) retaining >95% of the prestress values and threshold voltage shifts (ΔV(T)) of <1.6 V, versus <85% μ retention and ΔV(T) ≈ 20 V for the other trivalent ions. Detailed microstructural analysis indicates that Ga(3+) most effectively promotes oxide lattice formation. We conclude that the metal oxide lattice formation enthalpy (ΔH(L)) and metal ionic radius are the best predictors of IXZO oxygen getter efficacy.

  1. 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.

  2. Haematological and serum biochemical responses of chickens to hydric stress.

    PubMed

    Chikumba, N; Swatson, H; Chimonyo, M

    2013-09-01

    Dehydration can be extremely damaging to the performance and welfare of indigenous chickens. The effect of water restriction on haematological and biochemical parameters was compared in Naked Neck (NNK) and Ovambo (OVB) chickens. A total of 54 8-week-old pullets each of NNK and OVB chickens with an initial average weight of 641 ± 10 g/bird were randomly assigned to three water intake treatments with three replications, each having six birds. The water restriction treatments were ad libitum, 70% and 40% of ad libitum intake. Nine experimental pens with a floor space of 3.3 m2 per strain were used. Feed was provided ad libitum. Packed cell volume (PCV), erythrocyte count (RBC), mean corpuscular volume (MCV) and total leucocyte count (WBC), and biochemical parameters (uric acid (UA)), creatinine (CREAT), total protein (TP), albumin (ALB), globulin (GLOB), triglyceride (TGA), total cholesterol (TC), high- (HDLC) and low- (LDLC) density lipoprotein cholesterol and activity of alanine transaminase (ALT), alkaline phosphatase (ALP) and aspartate transaminase (AST) were determined from blood collected after 60 days of water restriction. PCV was higher (P < 0.05) in NNK than OVB chickens offered water ad libitum, but similar in birds offered 70% and 40% of ad libitum. There were no differences in RBC and MCV values between strains, but MCV was higher in birds on 40% than 70% of ad libitum water intake, irrespective of strain. Naked neck chickens had higher (P < 0.05) WBC values than OVB at 40% restriction level, but lower WBC than OVB at 70% water restriction level. UA, CREAT, TGA, TC, LDLC, TP and GLOB increased (P < 0.05) with each increment in water restriction, but the increase in CREAT and TC was more pronounced in OVB than NNK chickens. The opposite was observed for UA. ALT activity indicated that liver function was not affected by water restriction. It was concluded that the two strains can withstand up to 40% of ad libitum water restriction, but NNK tolerated water

  3. Molecular Dynamics Simulation of Thermal Transport in UO2 Containing Uranium, Oxygen, and Fission-product Defects

    NASA Astrophysics Data System (ADS)

    Liu, X.-Y.; Cooper, M. W. D.; McClellan, K. J.; Lashley, J. C.; Byler, D. D.; Bell, B. D. C.; Grimes, R. W.; Stanek, C. R.; Andersson, D. A.

    2016-10-01

    Uranium dioxide (UO2 ) is the most commonly used fuel in light-water nuclear reactors and thermal conductivity controls the removal of heat produced by fission, thereby governing fuel temperature during normal and accident conditions. The use of fuel performance codes by the industry to predict operational behavior is widespread. A primary source of uncertainty in these codes is thermal conductivity, and optimized fuel utilization may be possible if existing empirical models are replaced with models that incorporate explicit thermal-conductivity-degradation mechanisms during fuel burn up. This approach is able to represent the degradation of thermal conductivity due to each individual defect type, rather than the overall burn-up measure typically used, which is not an accurate representation of the chemical or microstructure state of the fuel that actually governs thermal conductivity and other properties. To generate a mechanistic thermal conductivity model, molecular dynamics (MD) simulations of UO2 thermal conductivity including representative uranium and oxygen defects and fission products are carried out. These calculations employ a standard Buckingham-type interatomic potential and a potential that combines the many-body embedded-atom-method potential with Morse-Buckingham pair potentials. Potential parameters for UO2 +x and ZrO2 are developed for the latter potential. Physical insights from the resonant phonon-spin-scattering mechanism due to spins on the magnetic uranium ions are introduced into the treatment of the MD results, with the corresponding relaxation time derived from existing experimental data. High defect scattering is predicted for Xe atoms compared to that of La and Zr ions. Uranium defects reduce the thermal conductivity more than oxygen defects. For each defect and fission product, scattering parameters are derived for application in both a Callaway model and the corresponding high-temperature model typically used in fuel-performance codes

  4. Molecular dynamics simulation of thermal transport in UO2 containing uranium, oxygen, and fission-product defects

    DOE PAGES

    Liu, Xiang -Yang; Cooper, Michael William D.; McClellan, Kenneth James; ...

    2016-10-25

    Uranium dioxide (UO2) is the most commonly used fuel in light-water nuclear reactors and thermal conductivity controls the removal of heat produced by fission, thereby governing fuel temperature during normal and accident conditions. The use of fuel performance codes by the industry to predict operational behavior is widespread. A primary source of uncertainty in these codes is thermal conductivity, and optimized fuel utilization may be possible if existing empirical models are replaced with models that incorporate explicit thermal-conductivity-degradation mechanisms during fuel burn up. This approach is able to represent the degradation of thermal conductivity due to each individual defect type,more » rather than the overall burn-up measure typically used, which is not an accurate representation of the chemical or microstructure state of the fuel that actually governs thermal conductivity and other properties. To generate a mechanistic thermal conductivity model, molecular dynamics (MD) simulations of UO2 thermal conductivity including representative uranium and oxygen defects and fission products are carried out. These calculations employ a standard Buckingham-type interatomic potential and a potential that combines the many-body embedded-atom-method potential with Morse-Buckingham pair potentials. Potential parameters for UO2+x and ZrO2 are developed for the latter potential. Physical insights from the resonant phonon-spin-scattering mechanism due to spins on the magnetic uranium ions are introduced into the treatment of the MD results, with the corresponding relaxation time derived from existing experimental data. High defect scattering is predicted for Xe atoms compared to that of La and Zr ions. Uranium defects reduce the thermal conductivity more than oxygen defects. For each defect and fission product, scattering parameters are derived for application in both a Callaway model and the corresponding high-temperature model typically used in fuel

  5. Magnetic, specific heat and electrical transport properties of oxygen-deficient nanosized rutile TiO2‑δ

    NASA Astrophysics Data System (ADS)

    Tran, Vinh Hung; Thi Quynh Hoa, Nguyen

    2017-03-01

    An oxygen-deficient nanosized {{TiO}}2-δ , δ ∼ 0.7 sample was synthesized by a solvothermal method, and was characterized to have both ∼3 nm amorphous solid and ∼36–46 nm diameter rutile nanowires. Physical properties of the sample were investigated by measuring magnetic, specific heat, electrical resistance and magnetoresitance properties. DC magnetization M(H) data confirm ferromagnetic behavior previously reported for undoped TiO2. Furthermore, M(T) dependence follows the power-law relation M{(T)\\propto (1-T/{T}C)}β in the near-critical regime, yielding Curie temperature {T}C ∼ 415 K and critical exponent β = 0.2. Moreover, our results of AC magnetic susceptibility measurements suggest an additional phase transition at {T}* ∼ 310 K, presumably due to spin orientation. The metallic-like electrical resistance exhibits a distinct drop below {T}* with a strong thermal hysteresis in the temperature range 225–275 K. Specific heat in the temperature range 20–300 K is well described by the sum of contributions from acoustic phonons with Debye temperature 605 K and optical phonons with Einstein temperature 113 K. Below 10 K the specific heat divulges a large excess, which can be interpreted as an additional contribution originating from soft potentials.

  6. Effect of silver nanoparticles' generation routes on the morphology, oxygen, and water transport properties of starch nanocomposite films

    NASA Astrophysics Data System (ADS)

    Cheviron, Perrine; Gouanvé, Fabrice; Espuche, Eliane

    2015-09-01

    A strategy involving the preparation of silver nanoparticles in a biodegradable polymer stemming from an ex situ or an in situ method using a green chemistry process is reported. The influence of the reducing agent concentration and the silver nanoparticles' generation route were investigated on the structure, the morphology, and the properties of the nanocomposite films. Two distinct silver nanoparticle populations in size were highlighted from the ex situ route (diameter around 5 nm for the first one and from 20 to 50 nm for the second one), whereas one population was highlighted from the in situ route (around 10 nm). No modification on the crystalline structure of the starch matrix was observed in presence of silver. Crystalline silver nanoparticles were obtained only from the in situ generation route. The decrease of the water sorption and the improvement of water and oxygen barrier properties were found to be not dependent on the reducing agent concentration but mainly on the crystalline structure of the silver nanoparticles associated to the presence of strong interface between the silver nanoparticles and the starch polymer matrix.

  7. Dopamine mediates striatal malonate toxicity via dopamine transporter-dependent generation of reactive oxygen species and D2 but not D1 receptor activation.

    PubMed

    Xia, X G; Schmidt, N; Teismann, P; Ferger, B; Schulz, J B

    2001-10-01

    Intrastriatal injection of the reversible succinate dehydrogenase inhibitor malonate results in both chemically induced hypoxia and striatal lesions that are similar to those seen in Huntington's disease and cerebral ischaemia. The mechanisms leading to neuronal death involve secondary excitotoxicity, the release of dopamine from nigrostriatal fibres and the generation of reactive oxygen species (ROS) including nitric oxide (NO) and hydroxyl radicals. Here, we further investigated the contribution and mechanism of dopamine on malonate-induced striatal lesions. Prior lesions of the nigrostriatal pathway with 6-OHDA or the depletion of striatal dopamine stores by pretreatment with reserpine, an inhibitor or the vesicular monoamine transporter type-2 (VMAT2), in combination with alpha-methyl-p-tyrosine resulted in a significant reduction of malonate-induced striatal lesion volumes. This was paralleled by block or reduction of the malonate-induced generation of ROS, as measured by the conversions of salicylate to 2,3-dihydroxybenzoic acid (2,3-DHBA) using microdialysis. Systemic or intrastriatal application of L-DOPA or dopamine, respectively, reconstituted malonate toxicity and the generation of ROS in 6-OHDA-lesioned rats. Block of the dopamine transporter by GBR12909 did not result in a reduction of malonate-induced dopamine release, but significantly reduced the generation of hydroxyl radicals. The D2 receptor agonist lisuride and the mixed D1 and D2 receptor agonist apomorphine, but not the D1 receptor agonist SKF38393, partially restored malonate toxicity in 6-OHDA-lesioned rats without increasing the generation of ROS. In line with these results sulpiride, an inhibitor of D2 receptors, reduced the malonate-induced lesion volume, whereas SCH23390, an inhbitor of D1 receptors, was ineffective. Our data suggest that malonate-induced dopamine toxicity to energetically impaired neurons is mediated by two independent pathways: (i) dopamine transporter uptake

  8. Hemodynamic response and oxygen transport in pigs resuscitated with maleimide-polyethylene glycol-modified hemoglobin (MP4).

    PubMed

    Drobin, Dan; Kjellstrom, B Thomas; Malm, Elisabeth; Malavalli, Ashok; Lohman, Jeff; Vandegriff, Kim D; Young, Mark A; Winslow, Robert M

    2004-05-01

    Cell-free Hb increases systemic and pulmonary pressure and resistance and reduces cardiac output and heart rate in animals and humans, effects that have limited their clinical development as "blood substitutes." The primary aim of this study was to evaluate the hemodynamic response to infusion of several formulations of a new polyethylene glycol (PEG)-modified human Hb [maleimide PEG Hb (MalPEGHb)] in swine, an animal known to be sensitive to Hb-induced vasoconstriction. Anesthetized animals underwent controlled hemorrhage (50% of blood volume), followed by resuscitation (70% of shed volume) with 10% pentastarch (PS), 4% MalPEG-Hb in lactated Ringer (MP4), 4% MalPEG-Hb in pentastarch (HS4), 2% MalPEG-Hb in pentastarch (HS2), or 4% stroma-free Hb in lactated Ringer solution (SFH). Compared with baseline, restoration of blood volume after resuscitation was similar and not significantly different for the PS (103%), HS2 (99%), HS4 (106%), and MP4 (87%) animals but significantly less for the SFH animals (66%) (P < 0.05). All solutions that contained MalPEG-Hb restored mean arterial and pulmonary pressure and cardiac output. Systemic vascular resistance was unchanged, and pulmonary arterial pressure and resistance were increased slightly. Both systemic and pulmonary vascular resistance increased significantly in animals that received SFH, despite less adequate blood volume restoration. Oxygen consumption was maintained in all animals that received MalPEG-Hb, but not PS. Base excess improved only with MalPEG-Hb and PS, but not SFH. Red blood cell O2 extraction was significantly increased in animals that received Hb, regardless of formulation. These data demonstrate resuscitation with MalPEG-human Hb without increasing systemic vascular resistance and support our previous observations in animals suggesting that the efficacy of low concentrations of PEG-Hb in the plasma results from reduced vasoconstriction.

  9. Glycosylation of fluoroquinolones through direct and oxygenated polymethylene linkages as a sugar-mediated active transport system for antimicrobials.

    PubMed

    Jung, M E; Yang, E C; Vu, B T; Kiankarimi, M; Spyrou, E; Kaunitz, J

    1999-09-23

    We report herein the synthesis and biological testing of several glycosylated derivatives of some fluoroquinolone antibiotics. In particular, we have prepared several glycosylated derivatives of ciprofloxacin (2) in which the carbohydrate units are linked to the free secondary amine of the piperazine unit by: (a) no linker (e.g., a glycosylamine), (b) a beta-oxyethyl linker, and (c) a gamma-oxypropyl linker. Both glucose and galactose were used as carbohydrates so that six compounds of this type were prepared, e.g., no linker 4a,b, oxyethyl linker 5a,b, and oxypropyl linker 6a,b. In addition the aryl glycosides of glucose and galactose (7a,b) were prepared from the active 1-(4-hydroxyphenyl)fluoroquinolone (3.) The syntheses of the glycosylamines 4a,b involved the direct condensation of glucose and galactose with the hydrochloride salt of ciprofloxacin (2). For the oxyalkyl-linked compounds, we first prepared the peracetylated omega-bromoalkyl glycopyranosides 14a,b and 15a,b and then coupled them to the allyl ester of ciprofloxacin (11) to give, after saponification to remove all of the esters, the desired fluoroquinolone carbohydrates 5a,b and 6a,b. The final series was prepared from 2,4,5-trifluorobenzoyl chloride (22) which gave 3 in four precedented steps. Coupling of 3 with the peracetylated glucosyl and galactosyl halides 12a,b and 26 afforded, after saponification, the desired aryl glycosides 7a,b. Six of these derivatives of ciprofloxacin-4a,b, 5a,b, and 6a,b-were subjected to microbiological screening. Of the six, compound 6a showed the highest activity. Since 6a would give the hydroxypropyl-substituted ciprofloxacin on hydrolysis and its activity is approximately 4-8 times less than that of ciprofloxacin (2), this implies that compound 6a is probably being actively transported. Thus preliminary results suggest that some of the compounds are stable in culture conditions and may be differentially transported by multiple resistant organisms. In some cases

  10. 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.

  11. 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

  12. Where are we at with point-of-care testing in haematology?

    PubMed

    Briggs, Carol; Kimber, Simon; Green, Laura

    2012-09-01

    Point-of-care testing (POCT) in haematology has continued to grow in popularity and uptake throughout the world. The increasing demand to reduce the turnaround time of test results, coupled with rapid improvements in technology, have led to the development of several devices that are designed for use in different clinical settings, with the hope of improving patient care. The most used POCT in haematology is measurement of haemoglobin concentration. Other POCT devices (used primarily in developing countries) for malaria screening and CD4+ T-lymphocytes for quantification of human-immunodeficiency-virus are becoming the cornerstone for the diagnosis and management of these disorders. New devices are also available for red cell indices, white blood cell count and platelets. In this review clinical studies that validate the use of such devices will be discussed, as well as the advantages and disadvantages of POCT in haematology. A disadvantage of POCT is a lack of training, poor standardization in obtaining blood samples and insufficient internal/external quality assessment. As there is every reason to expect that POCT use will increase in all pathology disciplines, including haematology, it is imperative that systems are put in place to oversee these issues.

  13. CRISPR-Cas9 technology and its application in haematological disorders.

    PubMed

    Zhang, Han; McCarty, Nami

    2016-10-01

    The recent advent of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR associated protein 9 (Cas9) system for precise genome editing has revolutionized methodologies in haematology and oncology studies. CRISPR-Cas9 technology can be used to remove and correct genes or mutations, and to introduce site-specific therapeutic genes in human cells. Inherited haematological disorders represent ideal targets for CRISPR-Cas9-mediated gene therapy. Correcting disease-causing mutations could alleviate disease-related symptoms in the near future. The CRISPR-Cas9 system is also a useful tool for delineating molecular mechanisms involving haematological malignancies. Prior to the use of CRISPR-Cas9-mediated gene correction in humans, appropriate delivery systems with higher efficiency and specificity must be identified, and ethical guidelines for applying the technology with controllable safety must be established. Here, the latest applications of CRISPR-Cas9 technology in haematological disorders, current challenges and future directions are reviewed and discussed.

  14. Haematological status of wintering great tits (Parus major) along a metal pollution gradient.

    PubMed

    Geens, Ann; Dauwe, Tom; Bervoets, Lieven; Blust, Ronny; Eens, Marcel

    2010-02-01

    In the long-term biomonitoring of wild populations inhabiting polluted areas, the use of non-destructive biomarkers as markers of condition is very important. We examined the possible effects of metal pollution on the haematological status of adult great tits (Parus major) along a well-established pollution gradient near a non-ferrous smelter in Belgium. We measured blood and feather metal concentrations and assessed the haematological status (amount of red blood cells, haemoglobin concentration, haematocrit, mean corpuscular volume and mean corpuscular haemoglobin) of adult great tits during winter at four study sites. Metal concentrations in blood and feathers indicated that cadmium and lead were the most important metals in the pollution gradient under study. Measurements of haematological parameters revealed that haemoglobin concentration, haematocrit, mean corpuscular volume and mean corpuscular haemoglobin were lower in great tits from the more polluted sites. These parameters were significantly negatively correlated with blood lead concentration. The amount of red blood cells, however, did not significantly differ among study sites. Our results indicate that the haematological status of great tits is negatively affected by metal pollution and may therefore be used as a successful biomarker for monitoring the negative impact of metal exposure in the wild.

  15. Normal haematological values of European hedgehogs (Erinaceus europaeus) from an English rehabilitation centre.

    PubMed

    Lewis, J C M; Norcott, M R; Frost, L M; Cusdin, P

    2002-11-09

    Blood samples were taken from 29 male and 21 female clinically normal European hedgehogs (Erinaceus europaeus) that had been overwintered in an English rehabilitation centre, and the mean (sd) and ranges of their haematological values were determined. The mean cellular volume and lymphocyte counts of the female hedgehogs were slightly but significantly higher than those of the male hedgehogs.

  16. Evaluation of the Sysmex pocH-1001 haematology analyser in an outdoor oncology service.

    PubMed

    Van Hecke, I; Vanden Bempt, I; Malfait, R; Van Den Bossche, J

    2010-01-01

    Since rapid blood count analysis as near patient testing is expanding, we evaluated the use of a Sysmex pocH-100i compact haematology analyser in an outdoor oncology setting according to the recently published International Council for Standardization in Haematology (ICSH) guidelines. In total, 838 blood samples from oncology patients were analysed by pocH-100i and re-analysed by a high-throughput haematology analyser for comparison (Abbott CD-4000 or Sysmex XE-2100) to evaluate in use imprecision, comparability and vote-outs. Imprecision was less than 5%, except for platelet enumeration in the low range (within-run imprecision 7%). Good comparability was found even for platelet enumeration in the low range (r2 = 0.82). Vote-outs were found in 10.6% of examined samples. In conclusion, the Sysmex pocH-100i demonstrates good imprecision conform with former publications, produces reliable results in normal and in lower ranges comparable to the results of high throughput haematology analysers. In a well controlled management plan the Sysmex pocH-100i is suitable for near patient testing in oncology.

  17. 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

  18. Oxygen transport from the atmosphere to soil gas beneath a slab-on-grade foundation overlying petroleum-impacted soil.

    PubMed

    Lundegard, Paul D; Johnson, Paul C; Dahlen, Paul

    2008-08-01

    Modeling and field study results suggest that, in the case of a building overlying an aerobically biodegradable vapor source (i.e., petroleum-impacted soil), the significance of vapor intrusion into the building depends on the source vapor concentration, the relative position of the vapor source and building, and the rate of O2 transport from the atmosphere to the soil gas beneath the building. This work quantified the latter at a house having about a 250 m2 slab-on-grade foundation footprint. It was constructed on 1.5 m of clean fill overlying a petroleum hydrocarbon-impacted soil layer undergoing methanogenesis. Soil gas O2 and CH4 profiles adjacent to and beneath the foundation were measured and then the soil gas beneath the slab was rapidly displaced with N2. The natural replenishment of O2 was monitored for 90 days using in situ O2 sensors, and the responses with time were similar, independent of location. The O2 replenishment rate was about 2500 g-O2/d immediately after the N2 flood and then it declined to 200-500 g-O2/d over 30 days. Weather events affected the O2 replenishment rate; an increase occurred during a strong wind period (> 3 m/s), and a decrease occurred during a heavy rainfall event. The spatial and temporal patterns in the O2 sensor responses and quantified O2 replenishment rates could not be accounted for by simple mechanistic hypotheses involving lateral diffusion or advection through the bulk soil, and instead the data suggest rapid replenishment immediately below the foundation followed by downward diffusion.

  19. Effects of short-term normobaric hypoxia on haematology, muscle phenotypes and physical performance in highly trained athletes.

    PubMed

    Basset, Fabien A; Joanisse, Denis R; Boivin, Frédéric; St-Onge, Josée; Billaut, François; Doré, Jean; Chouinard, Richard; Falgairette, Guy; Richard, Denis; Boulay, Marcel R

    2006-03-01

    This study aimed to determine the impact of short-term normobaric hypoxia on physiology and performance in highly trained athletes. Twelve (7 male and 5 female) athletes were randomly assigned into two groups and spent 8 h per night for two consecutive nights a week over 3 weeks under either short-term normobaric hypoxia (simulating 3636 m altitude, inspired O2=13%) or in normobaric normoxia in a single-blind study. Following a 3 week washout period, athletes were then exposed to the other condition. Athletes were tested for maximal oxygen consumption and time to exhaustion on an electromagnetically braked cycle ergometer before and after each treatment in addition to being tested for anaerobic performance (Wingate test) on a modified Monark cycle ergometer. Blood samples were taken throughout the experiment and vastus lateralis muscle biopsies were taken before and after each treatment. Increases in red blood cell count, haematocrit, haemoglobin, platelet number and erythropoietin concentration were observed following short-term normobaric hypoxia. Except for a modest decrease in phosphofructokinase activity following short-term normobaric hypoxia, no changes were observed in muscle enzyme activities, buffer capacity, capillary density or morphology. No performance measures were changed following short-term normobaric hypoxia or normobaric normoxia. Although short-term normobaric hypoxia exposure increased levels of a number of haematological parameters, this was not associated with improved aerobic or anaerobic performance in highly trained athletes.

  20. Effect of Plasmodium falciparum malaria parasites on haematological parameters in Ghanaian children.

    PubMed

    Squire, D S; Asmah, R H; Brown, C A; Adjei, D N; Obeng-Nkrumah, N; Ayeh-Kumi, P F

    2016-06-01

    Malaria is hyper-endemic in Ghana. Haematological alterations in the disease pathology may offer complimentary criteria to improve clinical and microscopy diagnosis. Our primary outcome was to evaluate haematological parameters in children with Plasmodium falciparum infections and report their predictive risk and diagnostic performance for malaria infections in Ghana. Haematological data, including thin and thick blood films were examined for children less than 12 years of age in a multicenter-based active case finding approach. Haematological changes were common in P. falciparum infected children and more pronounced in severe malaria cases. More so, a unit increase in parasiteamia increased the odds for severe malaria infection by 93 % [OR, 95 % CI: 1.93 (1.28-2.91); P value = 0.02]. In multivariate regression, low haemoglobin was a significant haematological change in predicting P. falciparum infections [OR, 95 % CI: 3.20 (1.26-7.09); P value = 0.001]. Low haemoglobin levels <11 g/dl was the most reliable indicator for P. falciparum infections [with a sensitivity of (64 %), specificity (71 %), positive predictive value (83 %) and likelihood ratio (2.2)]-even when evaluated in combination with leucocytosis, lymphocytopaenia and high neutrophil counts >7,500 µL. In malaria endemic settings, low haemoglobin concentration (<11 g/dl) in children with febrile illness should prompt a more diligent search for the malarial parasite to limit the misuse and abuse of anti-malarial drugs.

  1. Evaluation of the QBC Star centrifugal three-part differential haematology system.

    PubMed

    Erhabor, O; Richardson, G; Mohammed, I; Thornton, C; Bark, J; Hurst, M; Hamer, D; Kinsella, P

    2013-01-01

    The QBC Star haematology system includes the QBC Star centrifugal analytical analyser and the QBC Star tube system. Together, they are capable of producing a haematology profile on venous or capillary whole blood. The aim of this study is to compare full blood count (FBC) including differential white cell count performance between the QBC Star analyser and a gold standard Sysmex XE-2100 haematology analyser. The FBC performance was evaluated according to the National Committee for Clinical Laboratory Standards (NCCLS) document H20-A. Imprecision, correlation and linearity studies all showed excellent results. Overall, the haemoglobin, haematocrit, white cell count (WCC) and platelet count parameters showed excellent correlation. Mean corpuscular haemoglobin concentration (MCHC) results showed poor comparability. The white cell differential parameters showed good correlation within certain clinically significant limits. Imprecision for haemoglobin, haematocrit, WCC, MCHC and platelet count was considered acceptable. The re-read function was found to be stable over the five-hour testing period under the authors' laboratory environmental conditions. The subjective assessment by biomedical scientist staff demonstrated that the system was user friendly, required little maintenance, and no user calibration was required. Staff considered the user manual to be excellent. Overall, the QBC Star appears to be an excellent point-of-care (POC) dry haematology analyser that delivers clinically significant nine-parameter complete blood count and will make a good POC analyser for use in field hospitals, research, screening programmes, GP surgeries as well as in emergency and intensive care units. It is a health and safety-friendly analyser considering the fact that it uses dry haematology reagents instead of the bulky wet reagents that are often associated with liquid biohazard waste.

  2. A nightmare for haematology clinics: extensively drug-resistant (XDR) Acinetobacter baumannnii.

    PubMed

    Metan, Gökhan; Pala, Çiğdem; Kaynar, Leylagül; Cevahir, Fatma; Alp, Emine

    2014-12-01

    The purpose of our study was to share experience on demographic characteristics and clinical outcome of the patients infected with extensively drug-resistant Acinetobacter baumannii (XDRAB) in haematology clinics, focusing on the period with a sudden increase in the number of XDRAB cases. A regular patient-based infection control programme was set up in haematology clinics and haematopoietic stem cell transplant centre starting from 2008. An infection control nurse visited all patients daily. A form including demographic data and laboratory results were recorded for all patients. The source of infections was identified according to the criteria proposed by the Centers for Disease Control and Prevention. While haematology ward-acquired XRDAB was rare before 2012, between January 2012 and July 2013, 29 A. baumannii infection episodes were detected in 28 patients. All but one isolate were MDR and 72.4% (21 out of 29) were XDR. Blood cultures revealed A. baumannii in 26 out of 29 episodes. While the haematological malignancy was relapsing or not under remission in 15 patients, four patients were under remission, and 10 patients were newly diagnosed. The mortality rate was 81.2%. All patients with a poor outcome died in the first week after the index blood culture was performed. In 16 out of 29 episodes, the patients died before the culture results became available. Colistin was initiated for the treatment in 11 out of 29 episodes. Three patients received colistin combined with sulbactam or sulbactam containing beta-lactams; the remaining eight patients who received colistin monotherapy were already under carbapenems. In conclusion, XDRAB infections can easily become nightmares for haematology clinics without any reliable treatment option.

  3. Transport properties and photo electrochemical characterization of oxygen-deficient ASnO 3- δ (A=Ca, Sr and Ba)

    NASA Astrophysics Data System (ADS)

    Zidi, N.; Omeiri, S.; Hadjarab, B.; Bouguelia, A.; Akroun, A.; Trari, M.

    2010-08-01

    The deficient stannate BaSnO 3- δ, prepared at 980 °C in sealed tube, crystallizes in an ideal perovskite structure. The oxide exhibits a blue color, the bandgap is found to be 2.65 eV and the transition is directly allowed. The non-stoichiometry could not be measured, indicating no appreciable oxygen deficiency. Nevertheless, the transport properties were found to change markedly with the heat treatment. BaSnO 3- δ behaves as degenerate SC with a conductivity σ300 K (=1.63 Ω -1 cm -1) and where the level Ef drops above mobility edge to delocalized states. The electric balance leads to a simultaneous reduction of Sn 4+ inducing n-type behavior. The thermal variation of the thermopower indicates an electron mobility μ300 K (=0.013 cm 2 V -1 s -1) thermally activated. The metal-insulating transition is considered of Anderson type due to the random potential to oxygen vacancies. A predominant variable range hopping is predicted from the non-linearity of Ln σ versus T-1 plot. The capacitance measurement ( C-2- V), measured in KOH media, shows a linear behavior from which a flat band potential Vfb (=-0.67 VSCE) and a density ND (=7.59×10 20 cm -3) are determined. The deficient stannates CaSnO 3 and SrSnO 3 are reported for a comparative purpose. The decrease of Eg is ascribed to the increase of the conduction band width when going from Ba to Ca.

  4. 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 ...

  5. Horizontal transport and seasonal distribution of nutrients, dissolved oxygen and chlorophyll -a in the Gulf of Nicoya, Costa Rica: a tropical estuary

    NASA Astrophysics Data System (ADS)

    Kress, Nurit; Coto, Sandra Leon; Brenes, Carlos L.; Brenner, Stephen; Arroyo, Guillermo

    2002-01-01

    The distributions of salinity, temperature, nutrients, dissolved oxygen and chlorophyll -a (chl -a) concentrations in the Gulf of Nicoya, Costa Rica, during the rainy and dry seasons are presented. In the rainy season, the entire Gulf is strongly stratified due to high riverine discharge; surface temperature decreases and salinity increases towards the sea and most of the Gulf is undersaturated with dissolved oxygen. In the dry season, the Gulf is still stratified although without the strong fresh water signal identified in the rainy season. The lowest surface temperatures appear in the middle of the Gulf whilst the salinity generally decreases towards the upper Gulf. Only the deep waters (below 30 m depth) are undersaturated with dissolved oxygen. In the lower Gulf, oversaturation reaches up to 134% at the surface. The concentration of Si(OH) 4 in the Gulf is much higher during the rainy season than in the dry season, whilst PO 4 is not seasonally dependent. Surficial concentrations of NO 3+NO 2 in the upper Gulf are higher in the dry season than in the rainy season; whilst in most of the lower Gulf, the concentrations are lower in the dry season. Surficial chl -a concentrations in the Gulf are higher in the rainy season, in particular, close to the Tarcoles outflow. A three-component mixing diagram describes the spatial distribution of the nutrients, during both seasons. Riverine waters from the Tempisque (high nutrients and low salinity) are mixed with surface waters from the lower Gulf (higher salinity and lower nutrients). The resulting water then mixes with oceanic water. Salinity in relation to PO 4 is seasonally dependent in the upper Gulf; the riverine end member during the dry season is higher, by a factor of 4, than during the rainy season. There is a significant correlation between NO 3+NO 2 and salinity only during the dry season in the upper Gulf; this is probably a result of phytoplankton consumption of N, in the rainy season. The calculated NO 3+NO

  6. 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

  7. Highly Durable Supportless Pt Hollow Spheres Designed for Enhanced Oxygen Transport in Cathode Catalyst Layers of Proton Exchange Membrane Fuel Cells.

    PubMed

    Dogan, Didem C; Cho, Seonghun; Hwang, Sun-Mi; Kim, Young-Min; Guim, Hwanuk; Yang, Tae-Hyun; Park, Seok-Hee; Park, Gu-Gon; Yim, Sung-Dae

    2016-10-10

    Supportless Pt catalysts have several advantages over conventional carbon-supported Pt catalysts in that they are not susceptible to carbon corrosion. However, the need for high Pt loadings in membrane electrode assemblies (MEAs) to achieve state-of-the-art fuel cell performance has limited their application in proton exchange membrane fuel cells. Herein, we report a new approach to the design of a supportless Pt catalyst in terms of catalyst layer architecture, which is crucial for fuel cell performance as it affects water management and oxygen transport in the catalyst layers. Large Pt hollow spheres (PtHSs) 100 nm in size were designed and prepared using a carbon template method. Despite their large size, the unique structure of the PtHSs, which are composed of a thin-layered shell of Pt nanoparticles (ca. 7 nm thick), exhibited a high surface area comparable to that of commercial Pt black (PtB). The PtHS structure also exhibited twice the durability of PtB after 2000 potential cycles (0-1.3 V, 50 mV/s). A MEA fabricated with PtHSs showed significant improvement in fuel cell performance compared to PtB-based MEAs at high current densities (>800 mA/cm(2)). This was mainly due to the 2.7 times lower mass transport resistance in the PtHS-based catalyst layers compared to that in PtB, owing to the formation of macropores between the PtHSs and high porosity (90%) in the PtHS catalyst layers. The present study demonstrates a successful example of catalyst design in terms of catalyst layer architecture, which may be applied to a real fuel cell system.

  8. 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

  9. Exogenous Sphingosine-1-Phosphate Boosts Acclimatization in Rats Exposed to Acute Hypobaric Hypoxia: Assessment of Haematological and Metabolic Effects

    PubMed Central

    Chawla, Sonam; Rahar, Babita; Singh, Mrinalini; Bansal, Anju; Saraswat, Deepika; Saxena, Shweta

    2014-01-01

    Background The physiological challenges posed by hypobaric hypoxia warrant exploration of pharmacological entities to improve acclimatization to hypoxia. The present study investigates the preclinical efficacy of sphingosine-1-phosphate (S1P) to improve acclimatization to simulated hypobaric hypoxia. Experimental Approach Efficacy of intravenously administered S1P in improving haematological and metabolic acclimatization was evaluated in rats exposed to simulated acute hypobaric hypoxia (7620m for 6 hours) following S1P pre-treatment for three days. Major Findings Altitude exposure of the control rats caused systemic hypoxia, hypocapnia (plausible sign of hyperventilation) and respiratory alkalosis due to suboptimal renal compensation indicated by an overt alkaline pH of the mixed venous blood. This was associated with pronounced energy deficit in the hepatic tissue along with systemic oxidative stress and inflammation. S1P pre-treatment improved blood oxygen-carrying-capacity by increasing haemoglobin, haematocrit, and RBC count, probably as an outcome of hypoxia inducible factor-1α mediated erythropoiesis and renal S1P receptor 1 mediated haemoconcentation. The improved partial pressure of oxygen in the blood could further restore aerobic respiration and increase ATP content in the hepatic tissue of S1P treated animals. S1P could also protect the animals from hypoxia mediated oxidative stress and inflammation. Conclusion The study findings highlight S1P’s merits as a preconditioning agent for improving acclimatization to acute hypobaric hypoxia exposure. The results may have long term clinical application for improving physiological acclimatization of subjects venturing into high altitude for occupational or recreational purposes. PMID:24887065

  10. Monocarboxylate transporter-dependent mechanism confers resistance to oxygen- and glucose-deprivation injury in astrocyte-neuron co-cultures.

    PubMed

    Gao, Chen; Zhou, Liya; Zhu, Wenxia; Wang, Hongyun; Wang, Ruijuan; He, Yunfei; Li, Zhiyun

    2015-05-06

    Hypoxic and low-glucose stressors contribute to neuronal death in many brain diseases. Astrocytes are anatomically well-positioned to shield neurons from hypoxic injury. During hypoxia/ischemia, lactate released from astrocytes is taken up by neurons and stored for energy. This process is mediated by monocarboxylate transporters (MCTs) in the central nervous system. In the present study, we investigated the ability of astrocytes to protect neurons from oxygen- and glucose-deprivation (OGD) injury via an MCT-dependent mechanism in vitro. Primary cultures of neurons, astrocytes, and astrocytes-neurons derived from rat hippocampus were subjected to OGD, MCT inhibition with small interfering (si)RNA. Cell survival and expression of MCT4, MCT2, glial fibrillary acidic protein, and neuronal nuclear antigen were evaluated. OGD significantly increased cell death in neuronal cultures and up-regulated MCT4 expression in astrocyte cultures, but no increased cell death was observed in neuron-astrocyte co-cultures or astrocyte cultures. However, neuronal cell death in co-cultures was increased by exposure to MCT4- or MCT2-specific siRNA, and this effect was attenuated by the addition of lactate into the extracellular medium of neuronal cultures prior to OGD. These findings demonstrate that resistance to OGD injury in astrocyte-neuron co-cultures occurs via an MCT-dependent mechanism.

  11. [Reliability of electron-transport membranes and the role of oxygen anion-radicals in aging: stochastic modulation of the genetic program].

    PubMed

    Kol'tover, V K

    2010-01-01

    All biomolecular constructions and nanorecators are designed to perform preset functions. All of them operate with limited reliability, namely, for each and every device or bionanoreactor normal operation alternates with accidental malfunctions (failures). Timely preventive maintenance replacement (prophylaxis) of functional elements in cells and tissues, the so-called turnover, is the main line of assuring high system reliability of organism as a whole. There is a finite number of special groups of genes (reliability assuring structures, RAS) that perform supervisory functions over the preventive maintenance. In a hierarchic pluricellular organism, RAS are genetic regulatory networks of a special group of cells, like hypothalamic neurons in the suprachiasmatic nucleus of mammals. Of the primary importance is limited reliability of mitochondrial nanoreactors, since the random malfunctions of electron transport chains produce reactive anion-radicals of oxygen (superoxide radical, O2*(-)). With time, O2*(-) radicals initiate accumulation of irreparable damages in RAS. When these damages accumulate up to preset threshold level, a fatal decrease in reliability of RAS occurs. Thus, aging is the stochastic consequence of programmed deficiency in reliability of biomolecular constructions and nanoreactors including the genetically preset limit of the system reliability. This reliability approach provides the realistic explanation of the data on prolongation of life of experimental animals with antioxidants as well as the explanation of similar "hormetic" effects of ionizing radiation in low doses.

  12. Oxygen control with microfluidics.

    PubMed

    Brennan, Martin D; Rexius-Hall, Megan L; Elgass, Laura Jane; Eddington, David T

    2014-11-21

    Cellular function and behavior are affected by the partial pressure of O2, or oxygen tension, in the microenvironment. The level of oxygenation is important, as it is a balance of oxygen availability and oxygen consumption that is necessary to maintain normoxia. Changes in oxygen tension, from above physiological oxygen tension (hyperoxia) to below physiological levels (hypoxia) or even complete absence of oxygen (anoxia), trigger potent biological responses. For instance, hypoxia has been shown to support the maintenance and promote proliferation of regenerative stem and progenitor cells. Paradoxically, hypoxia also contributes to the development of pathological conditions including systemic inflammatory response, tumorigenesis, and cardiovascular disease, such as ischemic heart disease and pulmonary hypertension. Current methods to study cellular behavior in low levels of oxygen tension include hypoxia workstations and hypoxia chambers. These culture systems do not provide oxygen gradients that are found in vivo or precise control at the microscale. Microfluidic platforms have been developed to overcome the inherent limits of these current methods, including lack of spatial control, slow equilibration, and unachievable or difficult coupling to live-cell microscopy. The various applications made possible by microfluidic systems are the topic of this review. In order to understand how the microscale can be leveraged for oxygen control of cells and tissues within microfluidic systems, some background understanding of diffusion, solubility, and transport at the microscale will be presented in addition to a discussion on the methods for measuring the oxygen tension in microfluidic channels. Finally the various methods for oxygen control within microfluidic platforms will be discussed including devices that rely on diffusion from liquid or gas, utilizing on-or-off-chip mixers, leveraging cellular oxygen uptake to deplete the oxygen, relying on chemical reactions in

  13. Energy Requirements for the Transport of Methylthio-β-d-Galactoside by Escherichia coli: Measurement by Microcalorimetry and by Rates of Oxygen Consumption and Carbon Dioxide Production1

    PubMed Central

    Long, Richard A.; Martin, W. G.; Schneider, Henry

    1977-01-01

    The energy cost for maintenance of gradients of methylthio-β-d-galactoside in Escherichia coli was evaluated. Information was also obtained concerning the energy flow associated with gradient establishment under some circumstances. Energy flow was evaluated from transport-induced changes in the rate of heat evolution, oxygen consumption, and carbon dioxide production in metabolically active cells. Heats were measured with an isothermal calorimeter. Energy expenditure behavior was characterized by a transition that depended on the level of accumulation. The data for steady-state maintenance could be rationalized in terms of the Mitchell hypothesis, two models for influx and efflux, and a transition between them. At low levels of uptake, steady-state proton-methylthio-β-d-galactoside (TMG) symport for influx and efflux occurred via a nonenergy-requiring exchange process. The only energy requirement was that necessary to pump back in any TMG exiting via a leakage pathway (model I). Above the transition, all influx occurred with proton symport, but all exit, leak and carrier mediated, occurred without proton symport (model II). The H+/TMG stoichiometric ratio computed for the region of model II applicability (carbon source present, high level of uptake) approached 1. This value agreed with that of other workers for downhill β-galactoside flow, suggesting that the energy cost for both downhill and uphill flow was approximately the same. For low levels of uptake, initial establishment of the gradient was followed by a burst of metabolism that was much larger than that expected on the basis of the chemiosmotic hypothesis. In the absence of carbon source, the stimulation in respiration was sufficient to produce 13 times more protons than are apparently necessary to establish the gradient. The results indicate also that the nature of the biochemical process stimulated by TMG depends on its level of uptake. Insight into several aspects of the nature of these processes was

  14. 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.

  15. Non-malignant haematology research in the UK: looking forward to new opportunities.

    PubMed

    Collins, P W; Baglin, T P; Dang, R; Evans, G; Greaves, M; Laffan, M; Pasi, K J; Rose, P; Stanworth, S; Toh, C H

    2010-09-01

    Over the last few years there has been rapid and radical change in the way clinical research in the UK is funded and supported within the NHS. This has resulted from restructuring and major new investment in research infrastructure, co-ordinated through Clinical Local Research Networks (CLRNs) and equivalent organisations in the devolved nations. CLRNs have resources to support local researchers undertake studies that have been adopted on to the national research portfolio. For example, CLRNs can help with gaining local approvals or provide research nurses to recruit patients, undertake study procedures and perform data entry. CLRNs can establish Local Speciality Groups in a number of areas of medicine, including nonmalignant haematology. These new networks offer non-malignant haematology access to significant new resources and a major opportunity to support clinical research for the benefit of our patients.

  16. Age-related changes in haematology and serum chemistry of Weiser-Maples guineapigs (Cavia porcellus).

    PubMed

    Kitagaki, M; Yamaguchi, M; Nakamura, M; Sakurada, K; Suwa, T; Sasa, H

    2005-07-01

    Age-related changes in haematology and serum chemistry values were examined in male and female Weiser-Maples guineapigs (Cavia porcellus). Haematological changes that significantly (P<0.01) correlated with ageing were increased white blood cell and neutrophil counts in both sexes, decreased lymphocyte counts in both sexes, decreased reticulocyte and platelet counts in males, and decreased basophil counts in females. For serum chemistry, increases in total protein, triglycerides, blood urea nitrogen and creatinine were seen in both sexes, along with increases in total cholesterol in males and sodium in females. Decreased alkaline phosphatase in both sexes and decreased chloride in males were significantly (P<0.01) associated with age. These age-related changes are compared with the published literature.

  17. Oxygen Transport to Human Tissues.

    DTIC Science & Technology

    1981-06-01

    Respiration and CSF Acid-Base Balance John W. Severinghaus As my part of this delightful festival honoring Ulrich Luft. I plan to summarize the role of high...Tobias, M.C. and Drasdo. H.. eds. Woodstock . N.Y.: Overlook Press. pp. 117-124. Formand, S.A., Lansdowne, M.. Follansbee, J.N., and Hansen. J.E. 1968

  18. Haematological and spermatotoxic effects of ethylene glycol monomethyl ether in copper clad laminate factories

    PubMed Central

    Shih, T.; Hsieh, A.; Liao, G.; Chen, Y.; Liou, S.

    2000-01-01

    OBJECTIVES—To investigate the effects of ethylene glycol monomethyl ether (EGME) on haematology and reproduction in exposed workers.
METHODS—53 Impregnation workers from two factories that make copper clad laminate with EGME as a solvent were recruited as the exposed group. Another group of 121 lamination workers with indirect exposure to EGME was recruited as the control group. Environmental monitoring of concentrations of EGME in air and biological monitoring of urinary methoxyacetic acid (MAA) concentrations were performed. Venous blood was collected for routine and biochemical analyses. Semen was collected from 14 workers exposed to EGME for sperm analysis and was compared with 13 control workers.
RESULTS—Results of haematological examination showed that the haemoglobin, packed cell volume, and red blood cell count in the male workers exposed to EGME were significantly lower than in the controls. The frequency of anaemia in the exposed group (26.1%) was significantly higher than in the control group (3.2%). However, no differences were found between the female workers exposed and not exposed to EGME. After adjustment for sex, body mass index, and duration of employment, red blood cell count was significantly negatively associated with air concentrations of EGME, and haemoglobin, packed cell volume, and red blood cell count were significantly negatively associated with urinary concentrations of MAA. The pH of semen in the exposed workers was significantly lower than in the control workers, but there were no significant differences in the sperm count or sperm morphology between the exposed and control groups.
CONCLUSION—It can be concluded that EGME is a haematological toxin, which leads to anaemia in the exposed workers. However, the data from this study did not support the theory of a spermatotoxic effect of EGME.


Keywords: ethylene glycol monomethyl ether; haematological disorders; spermatotoxicity PMID:10769301

  19. Effect of storage time on haematological parameters in mullet, Mugil cephalus.

    PubMed

    Faggio, C; Casella, S; Arfuso, F; Marafioti, S; Piccione, G; Fazio, F

    2013-07-01

    The aim of the present study was to assess the effect of storage time at +4 °C on red blood cell count (RBC), haematocrit (Hct), haemoglobin (Hb), white blood cell count (WBC), thrombocyte count (TC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) in mullet (Mugil cephalus) using an automatic method. After blood collection (T0 ), all samples were analyzed using both the manual and automatic method. To test the validation of the automatic method, a paired t-test was applied, and no statistical difference was observed. The samples were successively divided into four different aliquots and stored at +4 °C to assess the haematological parameters using the automatic method. The first aliquot was refrigerated for 6 h, the second one for 24 h, the third one for 48 h and the last one at for 72 h. One-way repeated-measures ANOVA showed a significant effect of storage time (P < 0.05) on Hb, WBC, TC, MCH and MCHC. These results suggest that haematological parameters can be assessed within 6 h from blood collection when samples are stored at +4 °C because long-term storage modifies the results of the analyses. Further studies on these parameters could be still needed in various fish species to validate an appropriate method for haematological analysis useful not only for the evaluation of the health status of animal living in captivity and in aquaculture but also to have reliability environmental haematological biomarkers.

  20. 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.

  1. 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

  2. Comparative techno-economic analysis and process design for indirect liquefaction pathways to distillate-range fuels via biomass-derived oxygenated intermediates upgrading: Liquid Transportation Fuel Production via Biomass-derived Oxygenated Intermediates Upgrading

    SciTech Connect

    Tan, Eric C. D.; Snowden-Swan, Lesley J.; Talmadge, Michael; Dutta, Abhijit; Jones, Susanne; Ramasamy, Karthikeyan K.; Gray, Michel; Dagle, Robert; Padmaperuma, Asanga; Gerber, Mark; Sahir, Asad H.; Tao, Ling; Zhang, Yanan

    2016-09-27

    This paper presents a comparative techno-economic analysis (TEA) of five conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The four emerging pathways of interest are compared with one conventional pathway (Fischer-Tropsch) for the production of the hydrocarbon blendstocks. The processing steps of the four emerging pathways include: biomass to syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation. Conversion of biomass-derived syngas to oxygenated intermediates occurs via three different pathways, producing: 1) mixed alcohols over a MoS2 catalyst, 2) mixed oxygenates (a mixture of C2+ oxygenated compounds, predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate) using an Rh-based catalyst, and 3) ethanol from syngas fermentation. This is followed by the conversion of oxygenates/alcohols to fuel-range olefins in two approaches: 1) mixed alcohols/ethanol to 1-butanol rich mixture via Guerbet reaction, followed by alcohol dehydration, oligomerization, and hydrogenation, and 2) mixed oxygenates/ethanol to isobutene rich mixture and followed by oligomerization and hydrogenation. The design features a processing capacity of 2,000 tonnes/day (2,205 short tons) of dry biomass. The minimum fuel selling prices (MFSPs) for the four developing pathways range from $3.40 to $5.04 per gasoline-gallon equivalent (GGE), in 2011 US dollars. Sensitivity studies show that MFSPs can be improved with co-product credits and are comparable to the commercial Fischer-Tropsch benchmark ($3.58/GGE). Overall, this comparative TEA study documents potential economics for the developmental biofuel pathways via mixed oxygenates.

  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.

  4. Internet use for health information among haematology outpatients: a cross-sectional survey.

    PubMed

    Laurent, Michaël R; Cremers, Saskia; Verhoef, Gregor; Dierickx, Daan

    2012-03-01

    Patients are increasingly seeking health information on the Internet, but to the best of our knowledge, this has not been previously studied in haematology. We aimed to characterise online health information use and associated variables among adult outpatients in our tertiary-care centre in Flanders, Belgium. During a 6-week period, we distributed 477 anonymous self-administered questionnaires and received 451 (response rate 94.5%), of which 444 (93.1% of total) contained information on Internet use for health information, the primary outcome. Two hundred and thirty-two respondents (52.3%) had ever sought any health information online, and 187 (33.1%) conducted searches pertaining to their haematological disease in the past year. The latter was independently associated with younger age and a higher level of education in multivariate analysis. Internet users ranked the Internet higher and other resources lower as health information resources. Among Internet users, 196 (89.5%) would be interested in a list of reliable websites about their disease. Patients reported positive and negative aspects of online health information-seeking; it increased anxiety in some while it stimulated coping in others. We conclude that haematological patients commonly use the Internet for health information and report both positive and negative aspects of using this medium.

  5. Methods of minimal residual disease (MRD) detection in childhood haematological malignancies.

    PubMed

    Jółkowska, Justyna; Derwich, Katarzyna; Dawidowska, Małgorzata

    2007-01-01

    The appropriate management of haematological disorders must rely on a precise and long-term monitoring of the patient's response to chemotherapy and radiotherapy. Clinical data are not sufficient and that is why in the last decade it became the most important to improve the knowledge of haematological diseases on the basis of molecular techniques and molecular markers. The presence of residual malignant cells among normal cells is termed minimal residual disease (MRD). Nowadays a great progress has been made in the treatment of malignant diseases and in the development of reliable molecular techniques, which are characterised by high sensitivity (10-3- 10-6) and ability to distinguish between normal and malignant cells at diagnosis and during follow-up. Especially, MRD data based on quantitative analysis (RQ-PCR, RT-RQ-PCR) appear to be crucial for appropriate evaluation of treatment response in many haematological malignancies. Implementation of standardized approaches for MRD assessment into routine molecular diagnostics available in all oncohaematological centres should be regarded nowadays a crucial point in further MRD study development.

  6. 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.

  7. 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

    2015-03-25

    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.

  8. Chronic toxicity of nonylphenol and ethinylestradiol: haematological and histopathological effects in juvenile Common carp (Cyprinus carpio).

    PubMed

    Schwaiger, J; Spieser, O H; Bauer, C; Ferling, H; Mallow, U; Kalbfus, W; Negele, R D

    2000-11-01

    In recent ecotoxicological research, there is an increasing concern about alkylphenolic industrial chemicals, such as nonylphenol (NP), because of their estrogenic properties. Data on the general fish toxicity of these wide spread aquatic pollutants are scarce. In order to evaluate sublethal toxic effects of environmentally relevant concentrations of NP, juvenile Common carp (Cyprinus carpio) were exposed to NP concentrations ranging from 1 to 15 microg NP/l over a 70-day period. Classical toxicological endpoints, such as various haematological parameters and histopathological alterations were investigated. In a comprehensive protocol, besides NP-induced effects also alterations due to a treatment with the synthetic estrogen ethinylestradiol (EE2) were evaluated. After both the NP-exposure as well as the EE2-treatment, the predominant haematological finding was a severe anaemia. Histopathological alterations in the kidney, the liver and the spleen occurred exclusively after treatment with EE2, whereas NP-exposed fish did not show any tissue lesions. Depending on the haematological parameter examined, a NOEC between 1 and 5 microg NP/l could be established. From the present findings, it is assumed, that under field conditions, the NP-induced, general toxic effects, might outbalance the relatively weak estrogenic effects of this compound and possibly might disturb ecologically relevant processes such as fish reproduction.

  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 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

  11. Oxygen isotopes in single micrometer-sized quartz grains: tracing the source of Saharan dust over long-distance atmospheric transport

    NASA Astrophysics Data System (ADS)

    Aléon, Jérôme; Chaussidon, Marc; Marty, Bernard; Schütz, Lothar; Jaenicke, Ruprecht

    2002-10-01

    Oxygen isotope compositions were measured by ion microprobe in individual micrometer-sized quartz grains extracted from one aerosol sample collected on the Cape Verde Islands and from four surface samples (three soils and one sediment) representing potential source regions of aerosols in Western and Central Africa (Morocco, Algeria, Niger, and Chad). A large range of δ 18O values, from +6.2‰ to +39.3‰ is present within the aerosol quartz grains. The different size fractions of the quartz grains from the surface samples overlap nearly entirely this range but show significant differences in their δ 18O distributions for the different size fractions of the grains (i.e., different modes, different proportions of grains with low or high δ 18O, ...). These differences in δ 18O distributions can be related to different geological formations (i.e., mantle-derived magmatic rocks, crustal magmatic rocks, or sedimentary rocks) outcropping in each region, thus giving a fingerprint of the source region. Quartz grains with unusually high δ 18O values between +30‰ and +40‰ were attributed to lacustrine cherts formed in evaporitic environments (Chad basin). The existence of distinct δ 18O distributions for the surface samples, which reflect regional geology but indicate some transport of the grains, enables the characterization of mixing processes during dust emission in the atmosphere. Particles are mixed at a regional scale in the dust reservoir, but injection of fine particles into the high troposphere occurs as a discrete and localized event with no mixing during the subsequent long-range transport by the easterlies. The comparison of the δ 18O distribution of the quartz from the aerosol sample with the equivalent size fractions in surface samples shows that the Niger area is the more probable source region for the aerosol although the Moroccan source cannot be excluded. This method gives a valuable tool to trace the source region of dust into the atmosphere or

  12. RNA-Seq reveals expression signatures of genes involved in oxygen transport, protein synthesis, folding, and degradation in response to heat stress in catfish.

    PubMed

    Liu, Shikai; Wang, Xiuli; Sun, Fanyue; Zhang, Jiaren; Feng, Jianbin; Liu, Hong; Rajendran, K V; Sun, Luyang; Zhang, Yu; Jiang, Yanliang; Peatman, Eric; Kaltenboeck, Ludmilla; Kucuktas, Huseyin; Liu, Zhanjiang

    2013-06-17

    Temperature is one of the most prominent abiotic factors affecting ectotherms. Most fish species, as ectotherms, have extraordinary ability to deal with a wide range of temperature changes. While the molecular mechanism underlying temperature adaptation has long been of interest, it is still largely unexplored with fish. Understanding of the fundamental mechanisms conferring tolerance to temperature fluctuations is a topic of increasing interest as temperature may continue to rise as a result of global climate change. Catfish have a wide natural habitat and possess great plasticity in dealing with environmental variations in temperature. However, no studies have been conducted at the transcriptomic level to determine heat stress-induced gene expression. In the present study, we conducted an RNA-Seq analysis to identify heat stress-induced genes in catfish at the transcriptome level. Expression analysis identified a total of 2,260 differentially expressed genes with a cutoff of twofold change. qRT-PCR validation suggested the high reliability of the RNA-Seq results. Gene ontology, enrichment, and pathway analyses were conducted to gain insight into physiological and gene pathways. Specifically, genes involved in oxygen transport, protein folding and degradation, and metabolic process were highly induced, while general protein synthesis was dramatically repressed in response to the lethal temperature stress. This is the first RNA-Seq-based expression study in catfish in response to heat stress. The candidate genes identified should be valuable for further targeted studies on heat tolerance, thereby assisting the development of heat-tolerant catfish lines for aquaculture.

  13. The Pseudomonas putida HskA hybrid sensor kinase responds to redox signals and contributes to the adaptation of the electron transport chain composition in response to oxygen availability.

    PubMed

    Sevilla, Emma; Alvarez-Ortega, Carolina; Krell, Tino; Rojo, Fernando

    2013-12-01

    Pseudomonas putida has a branched aerobic electron transport that includes five terminal oxidases, each of which has different properties. The relative expression of each oxidase is carefully regulated to assemble the most suitable electron transport chain for the prevailing conditions. The HskA hybrid sensor kinase participates in this control, but the signals to which HskA responds were unknown. Here, the influence of HskA on the mRNA abundance of genes coding for all terminal oxidases and for the bc1 complex was analysed in cells growing under controlled aerobic, semiaerobic or microaerobic conditions. The results indicate that the influence of HskA on the expression of each terminal oxidase and the bc1 complex varies depending on oxygen availability. This effect was more pronounced under aerobic or semiaerobic conditions, but decreased under microaerobic conditions. The expression of hskA was regulated by oxygen availability. We show that HskA autophosphorylation is inhibited by ubiquinone but not by ubiquinol, its reduced derivative. This suggests that HskA could sense the oxidation state of the respiratory ubiquinones, which may be a key factor in HskA activity. Inactivation of hskA reduced growth rate and oxygen consumption, stressing the importance of HskA for the assembly of an efficient electron transport chain.

  14. High-dose carboplatin, etoposide and melphalan (CEM) with peripheral blood progenitor cell support as late intensification for high-risk cancer: non-haematological, haematological toxicities and role of growth factor administration.

    PubMed Central

    Benedetti Panici, P.; Pierelli, L.; Scambia, G.; Foddai, M. L.; Salerno, M. G.; Menichella, G.; Vittori, M.; Maneschi, F.; Caracussi, U.; Serafini, R.; Leone, G.; Mancuso, S.

    1997-01-01

    The present report describes the non-haematological toxicity and the influence of growth factor administration on haematological toxicity and haematopoietic recovery observed after high-dose carboplatin (1200 mg m(-2)), etoposide (900 mg m(-2)) and melphalan (100 mg m(-2)) (CEM) followed by peripheral blood progenitor cell transplantation (PBPCT) in 40 patients with high-risk cancer during their first-line treatment. PBPCs were collected during the previous outpatient induction chemotherapy programme by leukaphereses. CEM administration with PBPCT was associated with low non-haematological toxicity and the only significant toxicity consisted of a reversible grade III/IV increase in liver enzymes in 32% of the patients. Haematopoietic recovery was very fast in all patients and the administration of granulocyte colony-stimulating factor (G-CSF) plus erythropoietin (EPO) or granulocyte-macrophage colony-stimulating factor (GM-CSF) plus EPO after PBPCT significantly reduced haematological toxicity, abrogated antibiotic administration during neutropenia and significantly reduced hospital stay and patient's hospital charge compared with patients treated with PBPCT only. None of the patients died early of CEM plus PBPCT-related complications. Low non-haematological toxicity and accelerated haematopoietic recovery renders CEM with PBPC/growth factor support an acceptable therapeutic approach in an adjuvant or neoadjuvant setting. PMID:9099971

  15. Monitoring Oxygen Status.

    PubMed

    Toffaletti, J G; Rackley, C R

    Although part of a common "blood gas" test panel with pH and pCO2, the pO2, %O2Hb, and related parameters are independently used to detect and monitor oxygen deficits from a variety of causes. Measurement of blood gases and cooximetry may be done by laboratory analyzers, point of care testing, noninvasive pulse oximetry, and transcutaneous blood gases. The specimen type and mode of monitoring oxygenation that are chosen may be based on a combination of urgency, practicality, clinical need, and therapeutic objectives. Because oxygen concentrations in blood are extremely labile, there are several highly important preanalytical practices necessary to prevent errors in oxygen and cooximetry results. Effective utilization of oxygen requires binding by hemoglobin in the lungs, transport in the blood, and release to tissues, where cellular respiration occurs. Hydrogen ion (pH), CO2, temperature, and 2,3-DPG all play important roles in these processes. Additional measurements and calculations are often used to interpret and locate the cause and source of an oxygen deficit. These include the Hb concentration, Alveolar-arterial pO2 gradient, pO2:FIO2 ratio, oxygenation index, O2 content and O2 delivery, and pulmonary dead space and intrapulmonary shunting. The causes of hypoxemia will be covered and, to illustrate how the oxygen parameters are used clinically in the diagnosis and management of patients with abnormal oxygenation, two clinical cases will be presented and described.

  16. Limitations to oxygen transport and utilization during sprint exercise in humans: evidence for a functional reserve in muscle O2 diffusing capacity.

    PubMed

    Calbet, José A L; Losa-Reyna, José; Torres-Peralta, Rafael; Rasmussen, Peter; Ponce-González, Jesús Gustavo; Sheel, A William; de la Calle-Herrero, Jaime; Guadalupe-Grau, Amelia; Morales-Alamo, David; Fuentes, Teresa; Rodríguez-García, Lorena; Siebenmann, Christoph; Boushel, Robert; Lundby, Carsten

    2015-10-15

    To determine the contribution of convective and diffusive limitations to V̇(O2peak) during exercise in humans, oxygen transport and haemodynamics were measured in 11 men (22 ± 2 years) during incremental (IE) and 30 s all-out cycling sprints (Wingate test, WgT), in normoxia (Nx, P(IO2): 143 mmHg) and hypoxia (Hyp, P(IO2): 73 mmHg). Carboxyhaemoglobin (COHb) was increased to 6-7% before both WgTs to left-shift the oxyhaemoglobin dissociation curve. Leg V̇(O2) was measured by the Fick method and leg blood flow (BF) with thermodilution, and muscle O2 diffusing capacity (D(MO2)) was calculated. In the WgT mean power output, leg BF, leg O2 delivery and leg V̇(O2) were 7, 5, 28 and 23% lower in Hyp than Nx (P < 0.05); however, peak WgT D(MO2) was higher in Hyp (51.5 ± 9.7) than Nx (20.5 ± 3.0 ml min(-1) mmHg(-1), P < 0.05). Despite a similar P(aO2) (33.3 ± 2.4 and 34.1 ± 3.3 mmHg), mean capillary P(O2) (16.7 ± 1.2 and 17.1 ± 1.6 mmHg), and peak perfusion during IE and WgT in Hyp, D(MO2) and leg V̇(O2) were 12 and 14% higher, respectively, during WgT than IE in Hyp (both P < 0.05). D(MO2) was insensitive to COHb (COHb: 0.7 vs. 7%, in IE Hyp and WgT Hyp). At exhaustion, the Y equilibration index was well above 1.0 in both conditions, reflecting greater convective than diffusive limitation to the O2 transfer in both Nx and Hyp. In conclusion, muscle V̇(O2) during sprint exercise is not limited by O2 delivery, O2 offloading from haemoglobin or structure-dependent diffusion constraints in the skeletal muscle. These findings reveal a remarkable functional reserve in muscle O2 diffusing capacity.

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. Using oxygen at home

    MedlinePlus

    Oxygen - home use; COPD - home oxygen; Chronic obstructive airways disease - home oxygen; Chronic obstructive lung disease - home oxygen; Chronic bronchitis - home oxygen; Emphysema - home oxygen; Chronic respiratory ...

  3. Changes In Arterial Hemoglobin Oxygen Saturation During Transport From the Operating Room to the Postanesthesia Care Unit In Healthy Patients Breathing Room Air

    DTIC Science & Technology

    1998-12-16

    This occurs because nitrous oxide is 31 times more soluble in blood than nitrogen. If nitrogen was more soluble in blood than nitrous oxide this would...lack of data on pat i ent oxygenation during postoperative transfer, explainable in part by the difficulty of measuring blood gases under s uch...noninvasively measure the oxygen saturation of hemoglobin in arterial blood . The two types of oximeters are transmissive pulse oximeters and

  4. Evaluation of sulfonamide detoxification pathways in haematologic malignancy patients prior to intermittent trimethoprim-sulfamethoxazole prophylaxis

    PubMed Central

    Abouraya, Mahmoud; Sacco, James C; Kahl, Brad S; Trepanier, Lauren A

    2011-01-01

    AIMS Patients with haematologic malignancies have a reportedly high incidence of sulfamethoxazole (SMX) hypersensitivity. The objective of this study was to determine whether deficiencies in sulfonamide detoxification pathways, to include glutathione (GSH) and ascorbate (AA), and cytochrome b5 (b5) and cytochrome b5 reductase (b5R), were prevalent in these patients. A secondary pilot objective was to determine whether the incidence of drug hypersensitivity following intermittent trimethoprim-SMX (TMP-SMX) prophylaxis approached that reported for high dose daily regimens. METHODS Forty adult patients with haematologic malignancies (HM) and 35 healthy adults were studied; an additional 13 HM patients taking ascorbate supplements (HM-AA) were also evaluated. Twenty-two of 40 HM patients were prescribed and were compliant with TMP-SMX 960 mg three to four times weekly. RESULTS There were no significant differences between HM and healthy groups in plasma AA (median 37.2 µmvs. 33.9 µm) or red blood cell GSH (1.9 mmvs. 1.8 mm). However, plasma AA was correlated significantly with leucocyte b5/b5R reduction (r = 0.39, P = 0.002). Deficient b5/b5R activities were not found in HM patients. In fact, patients with chronic lymphocytic leukaemia or myeloma had significantly higher median activities (80.7 µmol mg–1 min−1) than controls (18.9 µmol mg–1 min−1, P = 0.008). After 3–4 weeks of treatment, no patients developed SMX-specific T cells and only one patient developed rash. CONCLUSIONS Deficiencies of blood antioxidants and b5/b5R reduction were not found in this population with haematologic malignancies, and the development of skin rash and drug-specific T cells appeared to be uncommon with intermittent TMP-SMX prophylaxis. PMID:21204907

  5. The dynamics of health in wild field vole populations: a haematological perspective.

    PubMed

    Beldomenico, Pablo M; Telfer, Sandra; Gebert, Stephanie; Lukomski, Lukasz; Bennett, Malcolm; Begon, Michael

    2008-09-01

    1. Pathogens have been proposed as potentially important drivers of population dynamics, but while a few studies have investigated the impact of specific pathogens, the wealth of information provided by general indices of health has hardly been exploited. By evaluating haematological parameters in wild populations, our knowledge of the dynamics of health and infection may be better understood. 2. Here, haematological dynamics in natural populations of field voles are investigated to determine environmental and host factors associated with indicators of inflammatory response (counts of monocytes and neutrophils) and of condition: measures of immunological investment (lymphocyte counts) and aerobic capacity (red blood cell counts). 3. Individuals from three field vole populations were sampled monthly for 2 years. Comparisons with individuals kept under controlled conditions facilitated interpretation of field data. Mixed effects models were developed for each cell type to evaluate separately the effects of various factors on post-juvenile voles and mature breeding females. 4. There were three well-characterized 'physiological' seasons. The immunological investment appeared lowest in winter (lowest lymphocyte counts), but red blood cells were at their highest levels and indices of inflammatory response at their lowest. Spring was characterized by a fall in red blood cell counts and peaks in indicators of inflammatory response. During the course of summer-autumn, red blood cell counts recovered, the immunological investment increased and the indicators of inflammatory response decreased. 5. Poor body condition appeared to affect the inflammatory response (lower neutrophil and monocyte peaks) and the immunological investment (lower lymphocyte counts), providing evidence that the capacity to fight infection is dependent upon host condition. 6. Breeding early in the year was most likely in females in better condition (high lymphocyte and red blood cell counts). 7. All the

  6. The dynamics of health in wild field vole populations: a haematological perspective

    PubMed Central

    Beldomenico, Pablo M.; Telfer, Sandra; Gebert, Stephanie; Lukomski, Lukasz; Bennett, Malcolm; Begon, Michael

    2010-01-01

    Summary Pathogens have been proposed as potentially important drivers of population dynamics, but while a few studies have investigated the impact of specific pathogens, the wealth of information provided by general indices of health has hardly been exploited. By evaluating haematological parameters in wild populations, our knowledge of the dynamics of health and infection may be better understood. Here, haematological dynamics in natural populations of field voles are investigated to determine environmental and host factors associated with indicators of inflammatory response (counts of monocytes and neutrophils) and of condition: measures of immunological investment (lymphocyte counts) and aerobic capacity (red blood cell counts). Individuals from three field vole populations were sampled monthly for 2 years. Comparisons with individuals kept under controlled conditions facilitated interpretation of field data. Mixed effects models were developed for each cell type to evaluate separately the effects of various factors on post-juvenile voles and mature breeding females. There were three well-characterized ‘physiological’ seasons. The immunological investment appeared lowest in winter (lowest lymphocyte counts), but red blood cells were at their highest levels and indices of inflammatory response at their lowest. Spring was characterized by a fall in red blood cell counts and peaks in indicators of inflammatory response. During the course of summer—autumn, red blood cell counts recovered, the immunological investment increased and the indicators of inflammatory response decreased. Poor body condition appeared to affect the inflammatory response (lower neutrophil and monocyte peaks) and the immunological investment (lower lymphocyte counts), providing evidence that the capacity to fight infection is dependent upon host condition. Breeding early in the year was most likely in females in better condition (high lymphocyte and red blood cell counts). All the

  7. A pilot programme of external quality assessment for general haematology in Italy.

    PubMed

    Salvati, A M; Maffi, D; Caprari, P; Marsili, G

    1995-01-01

    In the years 1984-1989 the Istituto Superiore di Sanità organized an EQAS for haematology (SVEQE) in Italy. A series of trials for haemocytometry, abnormal haemoglobins, HbA2, HbF, red cell G6PD and peripheral blood films, were carried out with the participation of 126 hospital laboratories, in different regions. SVEQE was an educative programme, aiming at promotion of quality assurance (QA) in laboratory haematology. At the same time an attempt was made to survey the analytical methods and instruments and to estimate the "state of the art" by the dispersion of all results. Participant laboratories were not scored for their performances. The operative protocol was harmonized to the guidelines established by WHO and ICSH; the trial specimens were prepared from normal or pathologic blood samples provided by blood banks or hospital departments. The trials for haemocytometry demonstrated a wide use of completely automated analyzers and in a steady state of performance during about five years. CVs, mainly for WBV and PLT, were somewhat higher than in other countries, where national QA systems have been established for a long time. Such discrepancies were not surprising in a pilot programme and were likely to be caused by inadequate internal quality control. The exercises for abnormal haemoglobins, HbA2, HbF and G6PD pointed out the need of using standardized methods according to the recommendations of ICSH. A large number of participating laboratories took part in the trial for blood cell morphology, being convinced of the educative function of this exercise; it is important to continue with systematic surveys, even including rare haematological disorders amongst the selected cases.

  8. Haematological and electrophoretic characterisation of β-thalassaemia in Yunnan province of Southwestern China

    PubMed Central

    Zhang, Jie; He, Jing; Mao, Xiaoqin; Zeng, Xiaohong; Chen, Hong; Su, Jie; Zhu, Baosheng

    2017-01-01

    Objectives β-Thalassaemia is widely found in Southwestern China. Characterisation of β-thalassaemia can improve screening and prenatal diagnosis for at-risk populations. Design A retrospective study. Methods In this study, the levels of haemoglobin alpha 2 (HbA2) and haemoglobin alpha (HbA) were analysed by gender for a total of 15 067 subjects screened by capillary electrophoresis. The cut-off value with the highest accuracy was established to identify β-thalassaemia in 723 patients suspected to have this disease. Haematological and electrophoretic characterisation of eight common types of β-thalassaemia were analysed in 486 β-thalassaemia subjects. Results HbA levels were significantly higher in men than in women, but there was no significant difference on HbA2 levels. A new cut-off value for the diagnosis of β-thalassaemia (HbA2≥4.0%) with the highest accuracy was proposed for the studied populations. Haemoglobin (Hb) was significantly higher in men compared with women (p<0.05), whereas no statistically significant differences were found for mean cell volume (MCV), mean cell haemoglobin (MCH), HbA and HbA2. The haemoglobin E (HbE) group showed comparatively higher values for haematological indices (Hb, MCV and MCH) than the other genotypes in heterozygous β-thalassaemia groups (p<0.05), and −28 (A>G) (HBB (β-globin):c.−78A>C) had significantly higher HbA2 values compared with other β-thalassaemia. Conclusions Ethnic groups have diversified β-globin gene mutations and considerable haematological variations. Our study will lay the foundation for screening programmes and clinical management of thalassaemia in Southwestern China. PMID:28143837

  9. 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.

  10. Haematology and some blood chemical parameters of young carp till the age of three years.

    PubMed

    Svetina, A; Matasin, Zeljka; Tofant, Alenka; Vucemilo, Marija; Fijan, N

    2002-01-01

    Haematological and biochemical analyses of blood were performed in carp (Cyprinus carpio L.) kept in small ponds. Caught and anaesthetised carp were clinically examined and blood samples were taken at regular intervals during the three years. In the first year of examinations, the haemoglobin and haematocrit values of carp fry significantly increased (P < 0.01) from June to September. The intensive growth of carp in the summer period in the second year was accompanied by adequate erythropoiesis. During hibernation haematocrit and haemoglobin significantly decreased (P < 0.05) and mean corpuscular haemoglobin concentration (MCHC) increased (P < 0.01) in both scaly and mirror carp. MCHC increased also with the age and increasing body weight of the fish. Mirror carp had lower haematocrit and haemoglobin values than scaly carp (P < 0.01). Comparative haematological analyses between carp of normal and poor body condition showed that moderate anaemia appeared in those with poor body condition. The results indicate that there is marked seasonal and age-dependent variation in the values of haematocrit and haemoglobin. Pond water quality investigations indicated good environmental conditions. A 50% increase (P < 0.05) of glucose concentration was found from June to September in the blood plasma of carp in the third year, accompanied by an even more increased (80%; P < 0.01) concentration of total lipids. At the same time, considerable changes of cholesterol and total protein concentrations were not observed. The results suggest that the investigated haematological and biochemical variables could be successfully utilised in monitoring the metabolic balance and health status of fish in intensive culture.

  11. 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.

  12. Haematology and clinical chemistry of hairy-nosed wombats (Lasiorhinus latifrons).

    PubMed

    Gaughwin, M D; Judson, G J

    1980-04-01

    The report summarises an investigation into the health of wombats (Lasiorhinus latifrons) in the field during the breeding season of a drought year. Health was assessed by morphometry, haematology and clinical chemistry and the findings were compared with those obtained for apparently healthy captaive wombats. The erythrocyte count was lower and the erythrocyte size greater in free-ranging wombats than in captaive wombats. Plasma values for potassium, urea, lactate dehydrogenase and aspartate transaminase were greater in free-ranging wombats than captive wombats. Plasma values for creatine, total bilirubin and alkaline phosphatase were lower in the free-ranging group.

  13. Long driving time is associated with haematological markers of increased cardiovascular risk in taxi drivers

    PubMed Central

    Chen, J; Chen, Y; Chang, W; Christiani, D

    2005-01-01

    Aims: To examine the association between driving time and changes in haematological markers of increased risks for cardiovascular diseases (CVD). Methods: The authors conducted a cross sectional analysis of baseline data from the Taxi Drivers' Health Study cohort in Taipei, Taiwan. They retrieved information on comorbidity, laboratory tests, age, and anthropometric measures from medical records of 1157 subjects (mean age 44.6 (SD 8.6) years). Whole blood cell (WBC) count was used as the primary haematological marker for increased CVD risk, and platelet count and haematocrit as the secondary markers. Standardised questionnaires were implemented to collect information on demographics, lifestyle, work related physical and psychosocial factors, and driving time profiles. Multiple regression was used to estimate the adjusted effects of driving time on three haematological markers. Results: The mean measured hematological marker was 6656 (SD 1656) cells x106/l for WBC, 47.2 (SD 3.5) % for hematocrit, and 243 (SD 52) cells x109/l for platelets. The driving time was 264 (SD 76) hours/month. Compared with drivers who drove ⩽208 hours/month (1st quartile cut off), drivers who drove >208 hours/month had a higher WBC count (by 317 x106/l; 95% CI 99 to 535), haematocrit (by 0.8%; 95% CI 0.3 to 1.2), and platelets (7.9 x109/l; 95% CI 1.0 to 14.8). After adjusting for conventional CVD risk factors (age, sex, smoking, hypertension, diabetes, and hypercholesterolaemia), obesity, alcohol drinking, regular exercise, and sociodemographics (education, marital status, income, and so on), long driving time was still associated with significant increases in WBC and platelets, whereas the effect on haematocrit was diminished and became statistically non-significant. Additional controls for physical workload, self-perceived job stress, and job dissatisfaction did not alter the associations with increased WBC and platelets. Conclusions: Longitudinal studies are needed to confirm the

  14. Haematological evaluation of ethanolic extract of Allium ascalonicum in male albino rats.

    PubMed

    Owoyele, B V; Alabi, O T; Adebayo, J O; Soladoye, A O; Abioye, A I R; Jimoh, S A

    2004-06-01

    The haematological effect of ethanolic extract of Allium ascalonicum was evaluated in male albino rats during a 21 day administration at the doses of 50, 100 and 200 mg/kg b.w, orally. Parameters evaluated include the serum lipids, red and white cell indices. The results showed that the extract administered decreased most of the parameters relating to red cell and increased most of those parameters relating to white cells. It also decreased the total cholesterol (TCH), high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) with no significant effect on the triglyceride levels.

  15. Normal haematological reference values in the adult black population of the Witwatersrand.

    PubMed

    Tikly, M; Blumsohn, D; Solomons, H D; Govender, Y; Atkinson, P M

    1987-07-18

    Normal haematological reference values for healthy adult blacks residing on the Witwatersrand are given. The haemoglobin concentration was 13.95 +/- 0.8 g/dl for women and 15.82 +/- 1.05 g/dl for men. Leucocyte counts were lower than those found in whites, being 5.60 +/- 1.51 X 10(9)/l for both sexes. Platelet counts were 280 +/- 59.4 X 10(9)/l for men and 317 +/- 64.0 X 10(9)/l for women. The differential counts and other parameters are given in the text.

  16. Mucormycosis in haematological patients: case report and results of prospective study in Saint Petersburg, Russia.

    PubMed

    Klimko, Nikolay N; Khostelidi, Sofya N; Volkova, Alisya G; Popova, Marina O; Bogomolova, Tatyana S; Zuborovskaya, Ludmila S; Kolbin, Aleksey S; Medvedeva, Nadezhda V; Zuzgin, Ilya S; Simkin, Sergey M; Vasilyeva, Nataliya V; Afanasiev, Boris V

    2014-12-01

    We prospectively observed 36 haematological patients with mucormycosis from nine hospitals of St. Petersburg during 2004-2013. The most frequent underlying diseases were acute leukaemia (64%), and main risk factors were prolonged neutropenia (92%) and lymphocytopenia (86%). In 50% of the patients, mucormycosis was diagnosed 1-65 days after invasive aspergillosis. Main clinical form of mucormycosis was pulmonary (64%), while two or more organ involvement was noted in 50% of the cases. The most frequent aetiological agents of mucormycosis were Rhizopus spp. (48%). Twelve-week survival rate was 50%. Combination therapy (echinocandins + amphotericin B forms) and recovery from the underlying disease significantly improved the survival rate.

  17. Age-related haematological changes and haemopathological responses in Chilean flamingos (Phoenicopterus chiliensis).

    PubMed

    Hawkey, C; Hart, M G; Samour, H J

    1984-04-01

    Full blood counts and fibrinogen estimations were carried out on 49 clinically normal Chilean flamingos of different ages. Compared with adults, chicks aged 2-3 months showed low haemoglobin levels, red cell counts, packed cell volumes and mean cell haemoglobin concentrations. There was a rise in haemoglobin level and red cell count with increasing age but the mean cell haemoglobin concentration did not reach optimum until the birds were mature. In chicks the total white cell count was high and the number of heterophils was widely variable. Findings on four sick adult birds provided preliminary evidence that clinical haematology has a potential diagnostic value in this species.

  18. A Study on Association between Common Haematological Parameters and Disease Activity in Rheumatoid Arthritis

    PubMed Central

    Barui, Gopinath; Adhikari, Anjan; Karmakar, Rupam; Ghosh, Udas Chandra; Das, Tushar Kanti

    2017-01-01

    Introduction Rheumatoid Arthritis (RA) is a chronic systemic inflammatory disease where assessment of disease activity is essential for management of patient. Currently, many composite scoring systems are used for evaluation of disease activity but they are mainly clinical-based. As several haematological parameters are altered due to systemic inflammatory process in RA, this study was intended to evaluate role of common haematological parameters to assess disease activity in RA. Aim To find out the association of disease activity of Rheumatoid Arthritis (RA) with platelet count, Mean Platelet Volume (MPV) and Haemoglobin (Hb) level so that these cost-effective haematological parameters can be used as additional factors to assess disease activity. Materials and Methods This hospital based cross-sectional study was done on newly diagnosed patients of RA along with age and sex matched healthy control population. Patients suffering from malignancies, renal failure, diabetes mellitus or RA patients on drug therapy were excluded. Clinically, disease activity of RA was measured using DAS 28-3 Score (Modified Disease Activity Score using three variables- tender joint count, swollen joint count and ESR). Haematological parameters were measured by automated cell counter. Results Total 80 cases were selected (60 female and 20 male). 48 patients with high disease activity (DAS 28-3>5.1) were labelled as Group-A and 32 with low to moderate disease activity (DAS 28-3 ≤5.1) as Group- B. Mean platelet count of patients of group A and group B were 4.53 lac/cmm and 2.17 lac/cmm respectively (p <0.001). MPV mean in group A and B were 11.86 fl and 10.19 fl respectively (p <0.001). Mean Hb (g/dl) was 10.05 and 12.25 for group A and B respectively (p=0.001) for male patients while in females it was 10.12 and 11.91 for group A and B, respectively (p=0.003). Mean platelet count and MPV in control population were 2.07 lac/cmm and 9.4 fl, respectively while mean Hb (g/dl) was 13.31 (male

  19. Haematological and biochemical alterations caused by epidural and intramuscular administration of xylazine hydrochloride in dromedary camels (Camelus dromedarius).

    PubMed

    Azari, Omid; Molaei, Mohammad Mahdi; Emadi, Ladan; Sakhaee, Ehsanollah; Sharifi, Hamid; Mehdizadeh, Sara

    2012-01-01

    This study was conducted in 16 healthy immature dromedary camels weighing 120-150 kg to evaluate and compare the effects of epidural and intramuscular injections of xylazine administered at 0.1 mg/kg and 0.2 mg/kg. Haematological parameters included haemoglobin, packed cell volume, total erythrocyte count and total leukocyte count. Biochemical parameters included alkaline phosphates, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine and glucose. Parameters were measured at different intervals before (baseline) and after the administration of drugs. Our study showed that the effect of xylazine on haematological and biochemical parameters is dose-dependant and is also related to the route of administration. The low dose of xylazine administered using both intramuscular and epidural methods showed minimal effects, whereas high doses of the drug, especially when injected intramuscularly, caused greater changes in haematological and biochemical parameters.

  20. 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.

  1. 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.

  2. Oxygen Therapy

    MedlinePlus

    ... stored as a gas or liquid in special tanks. These tanks can be delivered to your home and contain ... they won’t run out of oxygen. Portable tanks and oxygen concentrators may make it easier for ...

  3. INFLUENCE OF D-Nil plus (A POLYHERBAL DRUG) ON HAEMATOLOGICAL AND BIOCHEMICAL CHANGES IN DIABETIC INDUCED RATS

    PubMed Central

    Vanithamani, J.; Selvi, V.; Krishnaswamy, B. G.

    2006-01-01

    Diabetes mellitus, a metabolic disorder, is characterized by hyperglycemia and altered metabolism. The administration of D-Nil plus (a polyherbal drug) showed effective treatment for alloxan induced diabetes in rats. In diabetic rats, haematological profiles namely RBC, WBC, platlet count and haemoglobin were decreased whereas ESR was increased. Similarly biochemical parameters creatinine, urea and protein were decreased but cholesterol level was increased. After the treatment with D-Nil plus, haematological parameters and biochemical parameters were reversed. The results suggest that the D-Nil plus can be used for the treatment of diabetes. PMID:22557203

  4. Genetically regulated hepatic transcripts and pathways orchestrate haematological, biochemical and body composition traits

    PubMed Central

    Ponsuksili, Siriluck; Trakooljul, Nares; Hadlich, Frieder; Haack, Fiete; Murani, Eduard; Wimmers, Klaus

    2016-01-01

    The liver is the central metabolic organ and exhibits fundamental functions in haematological traits. Hepatic expression, haematological, plasma biochemical, and body composition traits were assessed in a porcine model (n = 297) to establish tissue-specific genetic variations that influence the function of immune-metabolism-correlated expression networks. At FDR (false discovery rate) <1%, more than 3,600 transcripts were jointly correlated (r = |0.22–0.48|) with the traits. Functional enrichment analysis demonstrated common links of metabolic and immune traits. To understand how immune and metabolic traits are affected via genetic regulation of gene expression, eQTLs were assessed. 20517 significant (FDR < 5%) eQTLs for 1401 transcripts were identified, among which 443 transcripts were associated with at least one of the examined traits and had cis-eQTL (such as ACO1 (6.52 × 10−7) and SOD1 (6.41 × 10−30). The present study establishes a comprehensive view of hepatic gene activity which links together metabolic and immune traits in a porcine model for medical research. PMID:28000754

  5. Effect of dietary alternative lipid sources on haematological parameters and serum constituents of Heterobranchus longifilis fingerlings.

    PubMed

    Babalola, T O O; Adebayo, M A; Apata, D F; Omotosho, J S

    2009-03-01

    The worldwide increase in aquaculture production and the decrease of wild fish stocks has made the replacement of fish oil (FO) in aquafeed industry a priority. Therefore, the use of terrestrial animal fats and vegetable oils, which has lower cost and larger supplies, may be good as substitute for FO. This study investigate the effects of total replacement of FO by two terrestrial animal fats (pork lard and poultry fat) and three vegetable oils (palm kernel oil, sheabutter oil and sunflower oil) on haematological and serum biochemical profile of Heterobranchus longifilis over 70 days. FO-diet was used as the control. The haematological parameters were significantly affected by dietary lipid sources. Serum total protein was not influenced by the dietary lipids. However, serum cholesterol was significantly higher in fish fed diet containing sunflower oil. Glucose and activities of liver enzymes in blood serum were significantly reduced in fish fed alternative lipids when compared with the control. These results indicate that FO can be replaced completely with alternative lipids without any serious negative health impacts.

  6. Sickle cell anaemia among Eti-Turks: haematological, clinical and genetic observations.

    PubMed

    Aluoch, J R; Kilinç, Y; Aksoy, M; Yüregir, G T; Bakioglu, I; Kutlar, A; Kutlar, F; Huisman, T H

    1986-09-01

    Haematological and genetic observations have been made on 71 SS Eti-Turk patients and their relatives from Cukurova (southern Turkey) and of immigrant families in The Netherlands. Similar data were collected for 25 Black patients and their relatives from Surinam, Netherlands Antilles, and Kenya. Haematological and clinical results were the same for both groups; the haemolytic anaemia in the Turkish patients was as severe as in the others. Haplotyping, involving nine restriction sites, identified haplotype 19 (Antonarakis et al, 1984) as the major type among the Eti-Turks; this chromosome has previously primarily been observed among SS patients from West Africa. The suggestion that the beta S-chromosome among Eti-Turks originates from that area is supported by a relatively high incidence of alpha-thalassaemia-2 (the 3.7 kb deletion), also frequently present in the Black population of West Africa, and by the absence of other major haplotypes, such as types 20 and 3, characteristic for the beta S-chromosome in the population of Central Africa and Kenya, and in Senegal, respectively. The Saudi Arabian type of beta S chromosome in association with the haplotype 19 beta S chromosome was present in only one Eti-Turk patient; this 30-year-old female was mildly affected and exhibited a high level of fetal haemoglobin.

  7. Guideline on the prevention of secondary central nervous system lymphoma: British Committee for Standards in Haematology.

    PubMed

    McMillan, Andrew; Ardeshna, Kirit M; Cwynarski, Kate; Lyttelton, Matthew; McKay, Pam; Montoto, Silvia

    2013-10-01

    The guideline group was selected to be representative of UK-based medical experts. Ovid MEDLINE, EMBASE and NCBI Pubmed were searched systematically for publications in English from 1980 to 2012 using the MeSH subheading 'lymphoma, CNS', 'lymphoma, central nervous system', 'lymphoma, high grade', 'lymphoma, Burkitt's', 'lymphoma, lymphoblastic' and 'lymphoma, diffuse large B cell' as keywords, as well as all subheadings. The writing group produced the draft guideline, which was subsequently revised by consensus by members of the Haemato-oncology Task Force of the British Committee for Standards in Haematology (BCSH). The guideline was then reviewed by a sounding board of ~50 UK haematologists, the BCSH and the British Society for Haematology (BSH) Committee and comments incorporated where appropriate. The 'GRADE' system was used to quote levels and grades of evidence, details of which can be found in Appendix I. The objective of this guideline is to provide healthcare professionals with clear guidance on the optimal prevention of secondary central nervous system (CNS) lymphoma. The guidance may not be appropriate to patients of all lymphoma sub-types and in all cases individual patient circumstances may dictate an alternative approach. Acronyms are defined at time of first use.

  8. 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.

  9. 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.

  10. In utero exposure to radiation and haematological malignancies: pooled analysis of Southern Urals cohorts

    PubMed Central

    Schüz, Joachim; Deltour, Isabelle; Krestinina, Lyudmila Y; Tsareva, Yulia V; Tolstykh, Evgenia I; Sokolnikov, Mikhail E; Akleyev, Alexander V

    2017-01-01

    Background: It is scientifically uncertain whether in utero exposure to low-dose ionising radiation increases the lifetime risk of haematological malignancies. Methods: We pooled two cohorts from the Southern Urals comprising offspring of female workers of a large nuclear facility (the Mayak Production Association) and of women living in areas along the Techa River contaminated by nuclear accidents/waste from the same facility, with detailed dosimetry. Results: The combined cohort totalled 19 536 subjects with 700 504 person-years at risk over the period of incidence follow-up, and slightly more over the period of mortality follow-up, yielding 58 incident cases and 36 deaths up to age 61 years. Risk was increased in subjects who received in utero doses of ⩾80 mGy (excess relative risk (ERR): 1.27; 95% confidence interval (CI): −0.20 to 4.71), and the risk increased consistently per 100 mGy of continuous exposure in utero (ERR: 0.77; CI: 0.02 to 2.56). No association was apparent in mortality-based analyses. Results for leukaemia and lymphoma were similar. A very weak positive association was observed between incidence and postnatal exposure. Conclusions: In summary, the results suggest a positive association between in utero exposure to ionising radiation and risk of haematological malignancies, but the small number of outcomes and inconsistent incidence and mortality findings preclude firm conclusions. PMID:27855443

  11. The validity of some haematological and ELISA methods for the diagnosis of canine heartworm disease.

    PubMed

    Martini, M; Capelli, G; Poglayen, G; Bertotti, F; Turilli, C

    1996-01-01

    Examinations for heartworm (Dirofilaria immitis) were performed on 175 impounded dogs from a hyperendemic area of the Po Valley (Italy). Each blood sample was used with five haematological diagnostic methods (filtration, direct smear, modified Knott, clotted blood and capillary tube) and three commercial ELISA kits (PetChek, Diasystems, Uni-Tec). The results were compared with the true infection status obtained from post-mortem examination of the heart, pulmonary arteries, thoracic venae cavae and lungs. The prevalence of the infection by adult worms at necropsy was 63%. The sensitivity of the tests ranged from 60% (capillary tube) to 81% (Diasystems) and the specificity from 88% (filtration) to 98% (PetChek). The results of all the tests differed significantly (p < 0.01) from those obtained at necropsy. The sensitivity of the tests was also assessed with respect to the differing numbers of worms in the hosts. A positive correlation between the worm burden and the sensitivity was observed in all the tests. It is apparent that the ELISA methods were better able to detect cases with a low number of worms than the haematological tests.

  12. Phenobarbitone-induced haematological abnormalities in idiopathic epileptic dogs: prevalence, risk factors, clinical presentation and outcome.

    PubMed

    Bersan, E; Volk, H A; Ros, C; De Risio, L

    2014-09-13

    The aim of this retrospective study was to assess prevalence, risk factors, clinical presentation and outcome of phenobarbitone induced haematological abnormalities (PBIHA) in dogs. The medical records of two veterinary referral institutions were searched for dogs diagnosed with idiopathic epilepsy and treated with PB as monotherapy or polytherapy between March 2003 and September 2010. Sixteen dogs had PBIHA; the median age at diagnosis was 69.5 months. Phenobarbitone was administered at a median dose of 3 mg/kg twice a day for a median period of 100.5 days and the median serum phenobarbitone level was 19 μg/ml. Two dogs had neutropenia, three had anaemia and thrombocytopenia, two had anaemia and neutropenia; the remaining nine had pancytopenia. All dogs were referred for non-specific clinical signs. Phenobarbitone was discontinued after diagnosis, and the median time to resolution of PBIHA was 17 days. The prevalence and risk factors for PBIHA were evaluated from a questionnaire survey of referring practices to obtain more detailed follow-up on cases diagnosed with idiopathic epilepsy. The prevalence rate of PBIHA was 4.2%, and the condition occurred in dogs treated with standard therapeutic doses often within the first three months after starting treatment. Serial haematological evaluations should be therefore considered from the beginning of phenobarbitone therapy to allow early diagnosis and treatment of PBIHA.

  13. Reporting unit size and measurement uncertainty: current Australian practice in clinical chemistry and haematology.

    PubMed

    Hawkins, Robert C; Badrick, Tony

    2015-08-01

    In this study we aimed to compare the reporting unit size used by Australian laboratories for routine chemistry and haematology tests to the unit size used by learned authorities and in standard laboratory textbooks and to the justified unit size based on measurement uncertainty (MU) estimates from quality assurance program data. MU was determined from Royal College of Pathologists of Australasia (RCPA) - Australasian Association of Clinical Biochemists (AACB) and RCPA Haematology Quality Assurance Program survey reports. The reporting unit size implicitly suggested in authoritative textbooks, the RCPA Manual, and the General Serum Chemistry program itself was noted. We also used published data on Australian laboratory practices.The best performing laboratories could justify their chemistry unit size for 55% of analytes while comparable figures for the 50% and 90% laboratories were 14% and 8%, respectively. Reporting unit size was justifiable for all laboratories for red cell count, >50% for haemoglobin but only the top 10% for haematocrit. Few, if any, could justify their mean cell volume (MCV) and mean cell haemoglobin concentration (MCHC) reporting unit sizes.The reporting unit size used by many laboratories is not justified by present analytical performance. Using MU estimates to determine the reporting interval for quantitative laboratory results ensures reporting practices match local analytical performance and recognises the inherent error of the measurement process.

  14. 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

  15. 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.

  16. Anaemia and other haematological abnormalities in patients admitted to long-term care.

    PubMed

    Granérus, A K; Nilsson-Ehle, H; Westin, J

    1992-01-01

    We investigated the occurence and causes of anaemia and other haematological abnormalities in 142 elderly patients (43 men, 99 women; median age 79 and 80 years), admitted to long-term care. Healthy 81-year-old subjects (n = 220) were used as reference group. Anaemia according to the WHO definition was much more common in the studied population (41%) than in a representative sample of 81-year-old subjects (10%). Somatically fit patients were less often anaemic (30%) than those with somatic illness (68%). The main causes for anaemia were: chronic disease (14.9%), recent haemorrhage (7.8%), iron deficiency (5.7%); and often multifactorial. Secondary leuko- or thrombocytosis occurred in 14 and 23%, drug-induced thrombocytopenia in 2.8% of the patients. Anaemia and other haematological abnormalities seen in elderly patients hospitalized for long-term care are often secondary to chronic or acute disorders. However, they also occur in patients without severe somatic impairment and many of them are reversible. Such findings should therefore not be neglected, but properly investigated, and if possible treated.

  17. Prospective study of hepatic, renal, and haematological surveillance in hazardous materials firefighters

    PubMed Central

    Kales, S; Polyhronopoulos, G; Aldrich, J; Mendoza, P; Suh, J; Christiani, D

    2001-01-01

    OBJECTIVES—To evaluate possible health effects related to work with hazardous materials as measured by end organ effect markers in a large cohort over about 2 years, and in a subcohort over 5 years.
METHODS—Hepatic, renal, and haematological variables were analysed from 1996-98 in hazardous materials firefighters including 288 hazardous materials technicians (81%) and 68 support workers (19%). The same end organ effect markers in a subcohort of the technicians were also analysed (n=35) from 1993-98. Support workers were considered as controls because they are also firefighters, but had a low potential exposure to hazardous materials.
RESULTS—During the study period, no serious injuries or exposures were reported. For the end organ effect markers studied, no significant differences were found between technicians and support workers at either year 1 or year 3. After adjustment for a change in laboratory, no significant longitudinal changes were found within groups for any of the markers except for creatinine which decreased for both technicians (p<0.001) and controls (p<0.01).
CONCLUSIONS—Health effects related to work are infrequent among hazardous materials technicians. Haematological, hepatic, and renal testing is not required on an annual basis and has limited use in detecting health effects in hazardous materials technicians.


Keywords: hazardous materials; firefighters; medical surveillance PMID:11160986

  18. Performance evaluation of the Sysmex XS-1000i automated haematology analyser.

    PubMed

    Ghys, T; Malfait, R; VAN den Bossche, J

    2009-10-01

    The Sysmex XS-1000i is a compact new, fully automated haematology analyser, designed to generate complete blood counts with five-part leucocyte differential. In our study, a Sysmex XS-1000i instrument was evaluated according to Clinical Laboratory Standards Institute (CLSI) and International Council for Standardization in Haematology (ICSH) guidelines. Precision, carry-over and linearity were determined. Using a total of 700 patient samples, results from the Sysmex XS-1000i were compared with those from a Sysmex XE-2100, an Abbott Cell Dyn 4000 and the manual reference leucocyte differential. Using quality control material, total and within-run imprecision was less than 3% except for platelets. The system demonstrated good linearity over the entire reporting range and no carry-over (<0.5%). The Sysmex XS-1000i showed good correlation with XE-2100, CD-4000 and the manual reference leucocyte differential. Overall flagging sensitivity and specificity were 91% and 48%, respectively. In conclusion, the Sysmex XS-1000i demonstrated good analytical performance, is able to generate a complete blood count with five-part differential on low blood volumes and has considerable back-up capacity.

  19. Bacillus spp. among hospitalized patients with haematological malignancies: clinical features, epidemics and outcomes.

    PubMed

    Ozkocaman, V; Ozcelik, T; Ali, R; Ozkalemkas, F; Ozkan, A; Ozakin, C; Akalin, H; Ursavas, A; Coskun, F; Ener, B; Tunali, A

    2006-10-01

    Between April 2000 and May 2005, 350 bacteraemic episodes occurred among patients treated in our haematology unit. Two hundred and twenty-eight of these episodes were caused by Gram-positive pathogens, most commonly coagulase-negative staphylococci and Staphylococcus aureus. One hundred and twenty-two episodes were due to Gram-negative pathogens, with a predominance of Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa. Bacillus bacteraemias constituted 12 of these episodes occurring in 12 patients, and accounted for 3.4% of all bacteraemic episodes. Of the 12 strains evaluated, seven were Bacillus licheniformis, three were Bacillus cereus and two were Bacillus pumilus. Seven episodes presented with bloodstream infection, three with pneumonia, one with severe abdominal pain and deterioration of liver function, and one with a catheter-related bloodstream infection. B. licheniformis was isolated from five patients who had been hospitalized at the same time. This outbreak was related to non-sterile cotton wool used during skin disinfection. B. cereus and B. licheniformis isolates were susceptible to cefepime, carbapenems, aminoglycosides and vancomycin, but B. pumilus isolates were resistant to all antibiotics except for quinolones and vancomycin. Two deaths were observed. In conclusion, Bacillus spp. may cause serious infections, diagnostic and therapeutic dilemmas, and high morbidity and mortality in patients with haematological malignancies. Both B. cereus and B. licheniformis may be among the 'new' Gram-positive pathogens to cause serious infection in patients with neutropenia.

  20. 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

  1. [Apneic oxygenation].

    PubMed

    Alekseev, A V; Vyzhigina, M A; Parshin, V D; Fedorov, D S

    2013-01-01

    Recent technological advances in thoracic and tracheal surgery make the anaesthesiologist use different respiratory techniques during the operation. Apneic oxygenation is a one of alternative techniques. This method is relatively easy in use, does not require special expensive equipment and is the only possible technique in several clinical situations when other respiratory methods are undesirable or cannot be used. However there is no enough information about apneic oxygenation in Russian. This article reviews publications about apneic oxygenation. The review deals with experiments on diffusion respiration in animals, physiological changes during apneic oxygenation in man and defines clinical cases when apneic oxygenation can be used.

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. Linezolid plasma concentrations and occurrence of drug-related haematological toxicity in patients with gram-positive infections.

    PubMed

    Cattaneo, Dario; Orlando, Giovanna; Cozzi, Valeria; Cordier, Laura; Baldelli, Sara; Merli, Stefania; Fucile, Serena; Gulisano, Cecilia; Rizzardini, Giuliano; Clementi, Emilio

    2013-06-01

    Retrospective studies have documented a significant association between linezolid (LNZ) plasma concentrations and drug-related haematological toxicity. However, the safe upper threshold level for LNZ plasma trough concentrations (Cmin values) has not been defined with certainty. A prospective observational study was performed aimed at comparing LNZ Cmin values in patients developing drug-related side effects with those measured in patients not experiencing LNZ toxicity. LNZ Cmin values were measured from the first week after starting therapy and were repeated periodically up to the end of treatment. Fifty patients, for a total of 210 LNZ Cmin evaluations, were considered. All patients (n=9) who developed drug-related haematological toxicity also had significantly higher plasma LNZ Cmin values during the first week of therapy (9.0±6.4 mg/L vs. 4.9±3.7 mg/L; P<0.01) and thereafter (9.3±5.4 mg/L vs. 4.4±3.4 mg/L; P<0.01). The significant association between LNZ plasma concentrations and haematological toxicity was also confirmed by multivariate logistic regression analysis including age, serum creatinine and concomitant medications as independent variables. A causal relationship between LNZ concentrations and the risk of developing drug-related haematological toxicity was observed. Accordingly, application of therapeutic drug monitoring may improve the safety outcome of patients receiving LNZ therapy.

  9. 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.

  10. Effect of Sweet Orange Fruit Waste Diets and Acidifier on Haematology and Serum Chemistry of Weanling Rabbits

    PubMed Central

    Daudu, Oluremi Martha; Sani, Rahamatu Usman; Adedibu, Iyetunde Ifeyori; Ademu, Lawrence Anebi; Bawa, Gideon Shaibu; Olugbemi, Taiye Sunday

    2014-01-01

    A total of thirty-five mixed breed (35) rabbits of average weight of 700 g aged 5-6 weeks were allocated to seven treatments in a completely randomised design to investigate the effect of sweet orange fruit waste (SOFW) and acidomix acidifier on haematology and serum chemistry. The diets were 0% SOFW, 10% SOFW with 0.5% acidomix, 10% SOFW with 0.7 acidomix, 15% SOFW with 0.5% acidifier, 15% SOFW with 0.7% acidifier, 20% SOFW with 0.5% acidifier, and 20% SOFW with 0.7% acidifier. Blood samples were analyzed for haemoglobin (hb) concentration, white blood cells (WBC), red blood cells (RBC), differential WBC count (lymphocyte, basophil, eosinophil, monocyte, and neutrophil), alanine amino transferase (ALT), alkaline phosphatase (ALP), aspartate amino transferase (AST), total protein, albumin, and globulin. There was no interaction between SOFW and acidifier for the haematological and most of the serum chemistry parameters but significant difference was observed in ALT; however the values were within the normal range. SOFW had no significant effect on all haematological and serum chemistry parameters. Acidomix had significant effect (P < 0.05) on haemoglobin concentration; rabbits fed 0.5% acidomix diets had higher values which were within the normal range. It is therefore concluded that SOFW with acidifier up to 20% had no detrimental effect on serum chemistry and haematology. PMID:26464931

  11. Excessive fluoride consumption increases haematological alteration in subjects with iron deficiency, thalassaemia, and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.

    PubMed

    Pornprasert, Sakorn; Wanachantararak, Phenphichar; Kantawong, Fahsai; Chamnanprai, Supoj; Kongpan, Chatpat; Pienthai, Nattasit; Yanola, Jintana; Duangmano, Suwit; Prasannarong, Mujalin

    2016-06-18

    Excessive fluoride consumption leads to accelerated red blood cell death and anaemia. Whether that increases the haematological alteration in subjects with haematological disorders (iron deficiency, thalassaemia, and G-6-PD deficiency) is still unclear. The fluoride in serum and urine and haematological parameters of students at Mae Tuen School (fluoride endemic area) were analysed and compared to those of students at Baan Yang Poa and Baan Mai Schools (control areas). Iron deficiency, thalassaemia, and G-6-PD deficiency were also diagnosed in these students. The students at Mae Tuen School had significantly (P < 0.001) higher levels of mean fluoride in the serum and urine than those in control areas. In both control and fluoride endemic areas, students with haematological disorders had significantly lower levels of Hb, Hct, MCV, MCH, and MCHC than those without haematological disorders. Moreover, the lowest levels of Hb, MCH, and MCHC were observed in the students with haematological disorders who live in the fluoride endemic area. Thus, the excessive fluoride consumption increased haematological alteration in subjects with iron deficiency, thalassaemia, and G-6-PD deficiency and that may increase the risk of anaemia in these subjects.

  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. 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.

  14. 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

  15. Quality control of the total lymphocyte count parameter obtained from routine haematology analyzers, and its relevance in HIV management.

    PubMed

    Marshall, S; Sippy, N; Broome, H; Abayomi, A

    2006-06-01

    Lylmphocyte subsets/CD4 T Helper cell enumeration in HIV care and treatment in resource constrained settings can be difficult to ascertain as a result of the lack of the necessary instrumentation, capacity and infrastructure. However. it is imperative to gain such information for patient monitoring in HIV. The Total Lymphocyte Count (TLC) is useful as a surrogate marker for CD4 count as recommended by the World Health Organisation (WHO) and to calculate CD4% for pacdiatric use. This study therefore sets out to determine and compare the accuracy of the total lymphocyte counts obtained from three haematology analysers designated A. B and C. that are in regular use for routine haemnatological parameters at the main referral hospital in Barbados. West Indies. The TLC of 263 HIV treatment naive individuals attending the HIV Reference Unit in Barbados were enumnerated on the three haematology analysers. The lymphosumn (Sum of lymphocyte subsets: T-helper cell. T-cytotoxic cells. B lymphocytes and Natural killer cells) should be equal to the TLC. and is derived by immunophenotypic analysis on a 4-colour flowcytometer. Machine C had the highest positive correlation between the TLC and the lymphosumn with and R' of 0.9031 compared to machine A with an R values of 0.7119 and Machine B with R(2) values of 0.637. These results show that there can be dramatic inaccuracies when using routine haematology analysers for both routine use. as a surrogate marker of CD4 or for derivation of CD4% in HIV management. It further demonstrates that all haematology analyzers require some form of Quality control. The possible lack of accuracy of the TLC by haematology analysers should be taken into consideration when following the recommendations of the WHO in resource poor settings or using it as a denominator for calculating CD4%.

  16. 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.

  17. 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.

  18. Effects of bifenthrin on some haematological, biochemical and histopathological parameters of common carp (Cyprinus carpio L.).

    PubMed

    Velisek, J; Svobodova, Z; Machova, J

    2009-11-01

    The aim of this study was to assess the effect of bifenthrin on common carp (Cyprinus carpio L.). The 96-h LC50 value of Talstar EC 10 (active substance 100 g l(-1) bifenthrin) was found to be 57.5 microg l(-1). Examination of haematological and biochemical profiles and histological tissue examination was performed on common carp after 96 h of exposure to Talstar EC 10 (57.5 microg l(-1)). The experimental group showed significantly higher (P < 0.01) values of plasma glucose, ammonia, aspartate aminotransferase and creatine kinase as well as the relative and absolute monocyte count, compared with the control group. Histological examination revealed teleangioectasiae of secondary gill lamellae and degeneration of hepatocytes. The bifenthrin-based Talstar EC 10 pesticide preparation was classified as a substance strongly toxic for fish.

  19. 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.

  20. The British Society for Haematology: 'What have the Romans ever done for us?'.

    PubMed

    Baglin, Trevor; Carrington, Paddy; Jackson, Graham

    2015-05-01

    '….Alright, but apart from the sanitation, medicine, education, wine, public order, irrigation, the roads, fresh water and public health………………what have the Romans ever done for us?' From Monty Python's Life of Brian An organizational review of the British Society for Haematology (BSH) was started in November 2013 and completed in June 2014. Many members of the Society participated in the surveys and have given their views, including those on the Shape of Training Greenaway report. Members' views were incorporated in the review and these have informed the eight strategic aims agreed at the Board meeting on 10 June 2014. The BSH will aim to realise these strategic aims over the next three to five years.

  1. 50th Annual Scientific Meeting of the British Society for Haematology.

    PubMed

    Thomas, Angela E

    2010-08-01

    The 50th Annual Scientific Meeting of the British Society for Haematology was notable, not only for its golden anniversary, but also because it coincided with the eruption of the Icelandic volcano, Eyjafjallajökull, and the ensuing travel chaos. In total, 28 speakers from overseas were unable to reach Edinburgh, including a significant number of British speakers who were stranded. However, owing to the superb efforts of the conference organisers and Edinburgh International Conference Centre staff, teleconferencing equipment was installed and all speakers were contacted and able to give their talks on time. The program, consisting of simultaneous sessions and plenary lectures, covered not only recent advances in clinical and laboratory hematology, but also reflected on the contribution of British hematology to the international arena over the past 50 years.

  2. Evaluation of a novel haematology analyser for use with feline blood.

    PubMed

    Weissenbacher, S; Riond, B; Hofmann-Lehmann, R; Lutz, H

    2011-03-01

    A novel haematology analyser was evaluated for its use with feline samples. Complete blood cell counts, a five-part differential count, and reticulocyte numbers were determined, and the results compared with reference data. Coefficients of correlation, Passing-Bablok regression analysis and Bland-Altmann difference plots with biases and 95% limits of agreement are reported. Precision and linearity were also studied. The instrument demonstrated very low imprecision, and the tested range of linearity exceeded the reference ranges provided by the manufacturer. For all parameters except monocytes (r = 0.65), the analyser results correlated well with reference methods. Compared with the manual count of aggregated reticulocytes, the instrument showed good agreement with a positive bias. The optical platelet count correlated well with the manual chamber count. In conclusion the analyser was found to be highly reliable for the analysis of feline blood samples in a large veterinary laboratory.

  3. Tales from the Jazz ASH: highlights from the 2013 American Society of Haematology meeting

    PubMed Central

    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

  4. Clinical, haematological and therapeutic studies on tropical theileriosis in water buffaloes (Bubalus bubalis) in Egypt.

    PubMed

    Osman, Salama A; Al-Gaabary, Magdy H

    2007-05-31

    Thirty buffaloes naturally infected with Theileria annulata and 10 parasitologically free controls were used to determine the potential clinical, haematological and therapeutic impact of tropical theileriosis in Egypt. The clinical signs in the infected buffaloes were pyrexia (40.5-41.5 degrees C), enlargement of superficial lymph nodes, slight nasal and ocular discharges, salivation, anaemia and respiratory distress. Eye lesions also were recorded. There was a significant decrease in erythrocyte counts and haemoglobin content and a significant decrease in total leucocyte counts in infected buffaloes compared to controls. Early treatment with buparvaquone was 100% effective in eliminating the protozoan parasites from the blood and lymph nodes and led to an improvement in the clinical state whereas treatment in the later stages of the disease whilst eliminating the parasites failed to improve the clinical condition of the animal.

  5. Granulocytic sarcoma in a patient with chronic myeloid leukaemia in complete haematological, cytogenetic and molecular remission

    PubMed Central

    Kittai, Adam; Yu, Eun-Mi; Tabbara, Imad

    2014-01-01

    Granulocytic sarcoma, also known as myeloid sarcoma, is an extramedullary tumour composed of immature myeloid cells. Granulocytic sarcoma is typically found in patients with acute myeloid leukaemia, accelerated phase or blast crisis of chronic myeloid leukaemia, myelodysplastic syndrome, or as an isolated event without bone marrow involvement. We present a case of granulocytic sarcoma in a patient with chronic myeloid leukaemia in the setting of complete haematological, molecular and cytogenetic remission. Our patient was first treated with imatinib for chronic-phase chronic myeloid leukaemia. After maintaining remission for 42 months, he developed a granulocytic sarcoma in his spine. In this case report, we describe our case, along with the three other cases reported in the literature. In addition to being a rare diagnosis, this case demonstrates the importance of being vigilant in diagnosing the cause of back pain and atypical symptoms in patients with a history of leukaemia. PMID:25538217

  6. Haematology of the racing Thoroughbred in Australia 1: reference values and the effect of excitement.

    PubMed

    Revington, M

    1983-04-01

    Eight hundred and sixteen blood samples were collected from horses at Sydney race tracks, 1 to 3 h before racing, and subjected to haematological analysis. Haemograms were also performed on 65 blood samples taken from horses at rest in their stalls. These were used as reference values of prerace and resting haemograms, respectively. The haemograms of 29 of the resting horses were compared with the haemograms of the same 29 horses the following day at the race track. Both samples were considered to be representative of their reference populations. In general, there was a significant increase from the resting to prerace packed cell volume, haemoglobin, red cell count, white cell count and total plasma protein, although the extent of the increases varied between horses and, in a minority, levels were unchanged or decreased. The degree of variability in the prerace samples was not greater than that of the resting samples.

  7. Haematological changes caused by Trichostrongylus colubriformis in lambs fed a dystrophogenic diet.

    PubMed

    Horton, G M; Owen, N C; Horak, I G; Schröder, J

    1977-06-01

    The effect of Trichostrongylus colubriformis on lambs maintained on a ration containing a low level of selenium and on animals receiving vitamin E and Se supplementation was investigated. The pathological changes seen in control animals slaughtered at the start of the experiment and in the animals which died during the course of the investigation revealed a high level of nutritional muscular dystrophy (NMD) in the lambs. There were no marked haematological changes in the control or infested sheep. Infestation was characterized by slight hypoalbuminaemia and gamma-globulinaemia. Serum levels of the enzymes AAT and CPK, which are important indicators of muscle necrosis and NMD, were greatly increased in sheep infested with T. colubriformis and not receiving supplementary Vit. E + Se. Data from this study therefore indicates that trichostrongylosis may aggravate the degree of muscle necrosis in lambs prone to the development of NMD.

  8. Effects of Aflatoxin on Some Haematological Parameters and Protective Effectiveness of Esterified Glucomannan in Merino Rams

    PubMed Central

    Dönmez, Nurcan; Dönmez, H. H.; Keskin, E.; Kısadere, İ.

    2012-01-01

    The objective of the present study was to evaluate the toxic effects of aflatoxin on some hematological parameters and to determine the preventive effectiveness of added glucomannan. In the study, 32 Merino rams were used, and the rams were separated equally to four groups as control (C), glucomannan (G), glucomannan + aflatoxin (AG), and aflatoxin (A). Erythrocyte, leukocyte count, hemoglobin, and hematocrit levels were decreased in A group compared with the other groups, and there was a reduction in similar parameters in AG group compared to control values. On the other hand, these parameters were tended to increase in AG group compared to A group values. Aflatoxicosis caused the lymphocytopenia and monocytopenia but increased percentage of neutrophil counts. In conclusion, the results determined in the study might be important to demonstrate the effects of aflatoxicosis and glucomannan on some haematological parameters before the clinical symptoms appear. PMID:22629132

  9. Variations in milk somatic cell count and haematologic values of dairy cows during lactation.

    PubMed

    Nikodémusz, E; Bedö, S; Pickler, A; Szép, P

    1994-01-01

    Variations in milk somatic cell count (SCC) and haematologic values were studied in a dairy cow colony of the Holstein-Friesian and Hungarian Red-Spotted breeds (n = 23) from May 1992 to July 1993. Milk and blood samples were taken approximately at monthly intervals and data were assigned into ten lunar months of lactation. After a maximum in month I, SCC dropped abruptly in month II and continued to decline through the subsequent four months, then it again tended to increase through months VII-X. The SCCs varied within the physiological range throughout the lactation period parallel with red blood cells and white blood cells constituting a major segment of the somatic cell population. Positive correlations were recorded between SCC and the blood variables (packed cell volume, red blood cell count, white blood cell count). The lactation pattern of SCC was comparable to previous observations.

  10. Abnormal biochemical and haematological indices in trypanosomiasis as a threat to herd production.

    PubMed

    Ohaeri, C C; Eluwa, M C

    2011-05-11

    Blood samples were collected from 46 domestic ruminants comprising of 23 trypanosomiasis infected and 23 uninfected control groups to study some biochemical and haematological effects of trypanosomiasis under natural condition. The effect of trypanosome infection in ruminant animals showed that infected animals had significantly lower (P<0.05) packed cell volume, erythrocyte count and higher (P<0.01) mean cell volumes than uninfected animals. Leucocytosis, reticulocytosis and thrombocytopenia were also observed. The infection also produced a decrease in albumin (P<0.001), significant increase in total protein and bilirubin levels. These changes were not seen in the animals that were not infected. The outcome of the work shows that herds are severely affected by the disease, and therefore supports the prospect of routine check as an epidemiologic tool in trypanosomiasis based on its abnormal effects in blood.

  11. 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

  12. 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…

  13. Dissolved oxygen: Chapter 6

    USGS Publications Warehouse

    Senn, David; Downing-Kunz, Maureen; Novick, Emily

    2016-01-01

    Dissolved oxygen (DO) concentration serves as an important indicator of estuarine habitat condition, because all aquatic macro-organisms require some minimum DO level to survive and prosper. The instantaneous DO concentration, measured at a specific location in the water column, results from a balance between multiple processes that add or remove oxygen (Figure 6.1): primary production produces O2; aerobic respiration in the water column and sediments consumes O2; abiotic or microbially-mediated biogeochemical reactions utilize O2 as an oxidant (e.g., oxidation of ammonium, sulfide, and ferrous iron); O2 exchange occurs across the air:water interface in response to under- or oversaturated DO concentrations in the water column; and water currents and turbulent mixing transport DO into and out of zones in the water column. If the oxygen loss rate exceeds the oxygen production or input rate, DO concentration decreases. When DO losses exceed production or input over a prolonged enough period of time, hypoxia ((<2-3 mg/L) or anoxia can develop. Persistent hypoxia or anoxia causes stress or death in aquatic organism populations, or for organisms that can escape a hypoxic or anoxic area, the loss of habitat. In addition, sulfide, which is toxic to aquatic organisms and causes odor problems, escapes from sediments under low oxygen conditions. Low dissolved oxygen is a common aquatic ecosystem response to elevated organic

  14. CT-guided percutaneous lung biopsies in patients with haematologic malignancies and undiagnosed pulmonary lesions.

    PubMed

    Gupta, Sanjay; Sultenfuss, Mark; Romaguera, Jorge E; Ensor, Joe; Krishnamurthy, Savitri; Wallace, Michael J; Ahrar, Kamran; Madoff, David C; Murthy, Ravi; Hicks, Marshall E

    2010-06-01

    We searched the electronic patient database at The University of Texas M. D. Anderson Cancer Center for patients who underwent computed tomography (CT)-guided needle biopsy between January 2001 and December 2005. Inclusion criteria were a known history of haematologic malignancy and a newly detected, undiagnosed pulmonary lesion on chest CT that required tissue sampling for diagnosis; 213 met these criteria. We analysed the biopsy results for diagnostic yield, factors affecting diagnostic yield and effect on treatment. Of 213 procedures, 191 (89.7%) yielded sufficient material for pathologic analysis; 130 (60%) yielded specific diagnoses, while 61 (28.6%) yielded nonspecific benign diagnoses. Lesions larger than 1 cm, cavitary lesions and lung masses were more likely to yield a specific diagnosis than were lesions smaller than 1 cm, lung nodules and consolidations. The most common specific diagnoses were malignancy (62.8%) and infection (34.3%). The latter was more common in patients with leukaemia, cavitary lung lesions or consolidations, active underlying malignancy, neutropenia, respiratory signs and symptoms and/or fever, bone marrow transplant recipients, and in patients receiving chemotherapy. Lung lesions discovered upon follow-up imaging in patients who did not have any respiratory signs/symptoms or fever were mostly malignant. Therapeutic changes were more likely after a specific diagnosis than after a nonspecific diagnosis or a nondiagnostic biopsy (88.4% vs. 18.1%; p < 0.0001). CT-guided lung biopsy has a high diagnostic yield in patients with haematologic malignancies that present with unexplained pulmonary lesions and provides a specific diagnosis in a majority of these patients, leading to therapeutic changes.

  15. Chronic environmental warming alters cardiovascular and haematological stress responses in European perch (Perca fluviatilis).

    PubMed

    Ekström, Andreas; Jutfelt, Fredrik; Fredrik Sundström, L; Adill, Anders; Aho, Teija; Sandblom, Erik

    2016-12-01

    Environmental warming and acute stress increase cardiorespiratory activity in ectothermic animals like fish. While thermal acclimation can buffer the direct thermal effects on basal cardiorespiratory function during chronic warming, little is known about how acclimation affects stress-induced cardiorespiratory responses. We compared cardiovascular and haematological responses to chasing stress in cannulated wild European perch (Perca fluviatilis) from a reference area at natural temperature (16 °C) with perch from the 'Biotest enclosure'; an experimental system chronically warmed (22 °C) by effluents from a nuclear power plant. Routine blood pressure was similar, but Biotest perch had slightly higher resting heart rate (59.9 ± 2.8 vs 51.3 ± 2.9 beats min(-1)), although the Q 10 for heart rate was 1.3, indicating pronounced thermal compensation. Chasing stress caused hypertension and a delayed tachycardia in both groups, but the maximum heart rate increase was 2.5-fold greater in Biotest fish (43.3 ± 4.3 vs 16.9 ± 2.7 beats min(-1)). Moreover, the pulse pressure response after stress was greater in reference fish, possibly due to the less pronounced tachycardia or a greater ventricular pressure generating capacity and thermally mediated differences in aortic compliance. Baseline haematological status was also similar, but after chasing stress, the haematocrit was higher in Biotest fish due to exacerbated red blood cell swelling. This study highlights that while eurythermal fishes can greatly compensate routine cardiorespiratory functions through acclimation processes, stress-induced responses may still differ markedly. This knowledge is essential when utilising cardiorespiratory variables to quantify and compare stress responses across environmental temperatures, and to forecast energetic costs and physiological constraints in ectothermic animals under global warming.

  16. Two years of a fungal aerobiocontamination survey in a Florentine haematology ward.

    PubMed

    Pini, Gabriella; Donato, Rosa; Faggi, Elisabetta; Fanci, Rosa

    2004-01-01

    The control of microbial air contamination in hospital wards has assumed great importance particularly for those hospital infections where an airborne infection route is hypothesised, such as aspergillosis. Invasive aspergillosis represents one of the most serious complications in immunocompromised patients. For some authors there is a direct association between this pathology and the concentrations of Aspergillus conidia in the air; in addition, reports of aspergillosis concurring during building construction have been frequent. In this study, two haematology wards were monitored for about 2 years in order to make both a qualitative and quantitative evaluation of fungal burden in the air, also in relation to major construction and demolition work taking place in the same building. Air samples were taken from the hospital rooms of neutropenic patients, in the corridors of their ward and outside the building. Total fungal concentration resulted higher outside (mean 572 Colony Forming Units/m3 of air), lower in the corridors (147 CFU/m3) and even lower in the rooms (50 CFU/m3). In all the samples we found the development of at least one fungal colony. Cladosporium was the most frequently isolated genus (57%), in contrast to Aspergillus spp. (2%). The average concentration of Cladosporium spp. was 24 CFU/m3 in the rooms, 78 CFU/m3 in the corridors and 318 CFU/m3 outside. The average concentration of Aspergillus spp. was 1.2 CFU/m3 in the rooms, 3.5 CFU/m3 in the corridors, 5.6 CFU/m3 outside. Our observations show low concentrations of Aspergillus fumigatus and A. flavus in all the environments examined and particularly in the rooms (0.09 and 0.10 CFU/m3 respectively); this observation could explain the absence of cases of invasive aspergillosis during the period of air monitoring in the two haematology wards.

  17. Haematological, inflammatory, and immunological responses in elite judo athletes maintaining high training loads during Ramadan.

    PubMed

    Chaouachi, Anis; Coutts, Aaron J; Wong, Del P; Roky, Rachida; Mbazaa, Abderraouf; Amri, Mohamed; Chamari, Karim

    2009-10-01

    During Ramadan, Muslims abstain from food and fluid intake from dawn to sunset for 1 month. These behavioural changes that accompany Ramadan may impact upon Muslim athletes who continue to train intensely. The aim of the present study was to evaluate the effect of Ramadan intermittent fasting (RIF) on the haematological, inflammatory, and immunological measures in elite judo athletes maintaining their usual high training loads. Haematological markers of inflammation, hormones, and immune status were studied in 15 elite male judo athletes before, during, and after Ramadan. The RIF produced small but significant changes in inflammatory, hormonal, and immunological profiles in judo athletes. Serum C-reactive protein increased from 2.93 +/- 0.26 mg.L-1 pre-Ramadan to 4.60 +/- 0.51 mg.L-1 at the end of Ramadan. Haptoglobin and antitrypsin also significantly increased at different phases during Ramadan, whereas homocysteine and prealbumin remained relatively unchanged. Albumin decreased slightly by mid-Ramadan, then recovered. Immunoglobulin Aincreased from 1.87 +/- 0.56 g.L-1 before Ramadan to 2.49 +/- 0.75 g.L-1 at the end, and remained high 3 weeks after. There were no changes in the leucocyte cell counts throughout the study. The mean blood level of thyroid-stimulating hormone and free thyroxine increased significantly during RIF. Most of these changes were within the normal ranges. These results suggest that athletes who continue to train intensely during Ramadan are liable to experience a myriad of small fluctuations in hormones, immunoglobulins, antioxidants, and inflammatory responses.

  18. Haematological and iron-related parameters of male endurance and strength trained athletes.

    PubMed

    Spodaryk, K

    1993-01-01

    To obtain more information on the effects of long-lasting endurance and strength training on the constituents of the blood, several haematological and iron-related parameters were measured at rest in 39 male athletes from the Polish team who participated in the Olympics in Seoul in 1988. The athletes were divided into two groups: endurance-trained subjects (group E, cyclists, canoeists and rowers; n = 22) and strength-trained subjects (group S, wrestlers and judo; n = 17). The control group was composed of untrained male subjects (n = 48). Blood samples were taken from an antecubital vein with the subject at rest for determinations of haemoglobin concentration ([Hb]), packed cell volume (PCV), erythrocyte (RBC) and reticulocyte count, plasma free haemoglobin concentration, haptoglobin concentration, serum iron, transferrin concentration and ferritin concentrations ([Ferr]); red blood cells were used for estimation of glutamato-oxalate transaminase (GOT) activity and free erythrocyte protoporphyrin concentration ([FEP]). The mean [Hb], PVC, RBC measured in the E athletes were significantly lower than in the control group but were comparable to those obtained in the S atheletes. There were no significantly differences in the haematological indices [mean corpuscular volume (MCV), mean copuscular haemoglobin and mean corpuscular haemoglobin concentration] between the groups of atheletes and the control group. A significant increase in reticulocytosis and GOT activity was observed in the endurance-trained athletes. No impairment of erythropoiesis was observed as indicated by several sensitive markers of haemoglobin formation (FEP, MCV and inspection of blood smears) in the athletes.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. 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.

  20. Blood gases, biochemistry and haematology of Galápagos marine iguanas (Amblyrhynchus cristatus)

    PubMed Central

    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

  1. 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.

  2. Association between Enterococcus bacteraemia and death in neutropenic patients with haematological malignancies.

    PubMed

    Todeschini, Giuseppe; Tecchio, Cristina; Borghero, Carlo; D'Emilio, Anna; Pegoraro, Enrico; de Lalla, Fausto; Benedetti, Paolo; Spolaore, Paolo; Pellizzer, Giampietro

    2006-10-01

    Fatality rates and prognostic factors for mortality due to Enterococcus spp. bacteraemia have not yet been fully defined in the setting of neutropenic patients affected with haematological malignancies. We have performed a retrospective, multi-centre cohort study on 98 episodes of Enterococcus bacteraemia occurring in patients hospitalised from January 1984 to December 2001 at the oncohaematology units in two tertiary-care hospitals (Verona Hospital and Vicenza Hospital, in north-east Italy). E. faecalis was isolated in 52 cases (53%), E. faecium in 39 (39.8%), E. avium in four, E. durans in one, and untyped Enterococcus spp. in two other cases; vancomycin resistance was detected in 15 (15.3%) isolates. A global mortality rate of 41.8% (41/98 cases) was revealed; Enterococcus spp. bacteraemia was associated with a fatal outcome in 29/98 cases (29.5%). The following variables were independently associated with an increased risk of death by multivariate analysis of survival: age > or =50 years (OR 3.74; 95% CI 1.35-10.32), pneumonia (OR 4.70; 95% CI 1.67-13.20), and shock (OR 13.7; 95% CI 1.23-152.43), while the initial phase of haematological disease (responsive to chemotherapy) appeared to be protective (OR 0.23; 95% CI 0.008-0.64, P level 0.005); however, pneumonia alone (OR 7.2, 95% CI 2.52-20.88) was independently associated with fatal outcome by multivariate analysis for death related to enterococcal bacteraemia. In our experience, the poor outcome proper to enterococcal bacteraemia appears to be directly related to underlying disease, patient's age, presence of pneumonia and shock; in contrast, severe neutropaenia, antibiotic resistance, and species of Enterococcus do not appear to affect the fatality rate significantly.

  3. The effect of a Ta oxygen scavenger layer on HfO2-based resistive switching behavior: Thermodynamic stability, electronic structure, and low-bias transport

    DOE PAGES

    Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; ...

    2016-02-15

    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 Schottkymore » 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. Lastly, 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.« less

  4. 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.

  5. 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.

  6. Oxygen safety

    MedlinePlus

    ... with electric motors Electric baseboard or space heaters Wood stoves, fireplaces, candles Electric blankets Hairdryers, electric razors, ... Therapy.aspx . Accessed February 9, 2016. National Fire Protection Association. Medical oxygen. Updated July 2013. www.nfpa. ...

  7. 49 CFR 175.501 - Special requirements for oxidizers and compressed oxygen.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... oxygen. 175.501 Section 175.501 Transportation Other Regulations Relating to Transportation PIPELINE AND... Special requirements for oxidizers and compressed oxygen. (a) Compressed oxygen, when properly labeled Oxidizer or Oxygen, may be loaded and transported as provided in this section. Except for...

  8. 49 CFR 175.501 - Special requirements for oxidizers and compressed oxygen.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... oxygen. 175.501 Section 175.501 Transportation Other Regulations Relating to Transportation PIPELINE AND... Special requirements for oxidizers and compressed oxygen. (a) Compressed oxygen, when properly labeled Oxidizer or Oxygen, may be loaded and transported as provided in this section. Except for...

  9. 49 CFR 175.501 - Special requirements for oxidizers and compressed oxygen.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... oxygen. 175.501 Section 175.501 Transportation Other Regulations Relating to Transportation PIPELINE AND... Special requirements for oxidizers and compressed oxygen. (a) Compressed oxygen, when properly labeled Oxidizer or Oxygen, may be loaded and transported as provided in this section. Except for...

  10. 49 CFR 175.501 - Special requirements for oxidizers and compressed oxygen.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... oxygen. 175.501 Section 175.501 Transportation Other Regulations Relating to Transportation PIPELINE AND... Special requirements for oxidizers and compressed oxygen. (a) Compressed oxygen, when properly labeled Oxidizer or Oxygen, may be loaded and transported as provided in this section. Except for...

  11. 49 CFR 175.501 - Special requirements for oxidizers and compressed oxygen.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... oxygen. 175.501 Section 175.501 Transportation Other Regulations Relating to Transportation PIPELINE AND... Special requirements for oxidizers and compressed oxygen. (a) Compressed oxygen, when properly labeled Oxidizer or Oxygen, may be loaded and transported as provided in this section. Except for...

  12. Electron transport and stability of the oxygen subsystem of YBa2Cu3O7-δ single crystals upon prolonged exposure to air

    NASA Astrophysics Data System (ADS)

    Khadzhai, G. Ya.; Vovk, R. V.

    2014-12-01

    Conductivity in the basal ab-plane of optimally oxygen-doped YBa2Cu3O7-δ single crystals was investigated before and after a prolonged exposure to air. The prolonged exposure was shown to increase the number of effective scattering centers for normal carriers. The excess conductivity for the samples studied was found to be an exponential function of temperature in a wide temperature range, while near the critical temperature Tc it is satisfactorily described by the Aslamazov-Larkin model. It was found that a prolonged exposure to air results in a considerable extension of the temperature range in which the pseudogap state is realized and a narrowing of the linear part of the ρab(T) dependence.

  13. Detection of EPO doping and blood doping: the haematological module of the Athlete Biological Passport.

    PubMed

    Schumacher, Yorck Olaf; Saugy, Martial; Pottgiesser, Torben; Robinson, Neil

    2012-11-01

    The increase of the body's capacity to transport oxygen is a prime target for doping athletes in all endurance sports. For this pupose, blood transfusions or erythropoiesis stimulating agents (ESA), such as erythropoietin, NESP, and CERA are used. As direct detection of such manipulations is difficult, biomarkers that are connected to the haematopoietic system (haemoglobin concentration, reticulocytes) are monitored over time (Athlete Biological Passport (ABP)) and analyzed using mathematical models to identify patterns suspicious of doping. With this information, athletes can either be sanctioned directly based on their profile or targeted with conventional doping tests. Key issues for the appropriate use of the ABP are correct targeting and use of all available information (e.g. whereabouts, cross sectional population data) in a forensic manner. Future developments of the passport include the correction of all concentration-based variables for shifts in plasma volume, which might considerably increase sensitivity. New passport markers from the genomic, proteomic, and metabolomic level might add further information, but need to be validated before integration into the passport procedure. A first assessment of blood data of federations that have implemented the passport show encouraging signs of a decreased blood-doping prevalence in their athletes, which adds scientific credibility to this innovative concept in the fight against ESA- and blood doping.

  14. 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.

  15. 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.

  16. 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.

  17. Hemoglobin-Based Nanoarchitectonic Assemblies as Oxygen Carriers.

    PubMed

    Jia, Yi; Duan, Li; Li, Junbai

    2016-02-10

    Safe and effective artificial oxygen carriers are the subject of great interest due to the problems of traditional blood transfusion and enormous demand in clinical use. In view of its unique oxygen-transport ability and normal metabolic pathways, hemoglobin is regarded as an ideal oxygen-carrying unit. With advances in nano-biotechnology, hemoglobin assemblies as artificial oxygen carriers achieve great development. Here, recent progress on hemoglobin-based oxygen carriers is highlighted in view of two aspects: acellular hemoglobin-based oxygen carriers and cellular hemoglobin-based oxygen carriers. These novel oxygen carriers exhibit advantages over traditional carriers and will greatly promote research on reliable and feasible oxygen carriers.

  18. 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.

  19. Optimization of Positive End-Expiratory Pressure targeting the best arterial oxygen transport in the Acute Respiratory Distress Syndrome: the OPTIPEP study.

    PubMed

    Chimot, Loïc; Fedun, Yannick; Gacouin, Arnaud; Campillo, Boris; Marqué, Sophie; Gros, Antoine; Delour, Pierre; Bedon-Carte, Sandrine; Le Tulzo, Yves

    2016-12-13

    The optimal setting for positive end-expiratory pressure (PEEP) in mechanical ventilation remains controversial in the treatment of acute respiratory distress syndrome (ARDS). The aim of this study was to determine the optimum PEEP level in ARDS, which we defined as the level that allowed the best arterial oxygen delivery (DO2).We conducted a physiological multicenter prospective study on patients who suffering from ARDS according to standard definition and persistent after 6 hours of ventilation. The PEEP was set to 6 cmH2O at the beginning of the test and then was increased by 2 cmH2O after at least 15 min of being stabilized until the plateau pressure achieved 30 cmH2O. At each step, the cardiac output was measured by trans-esophageal echocardiography and gas blood was sampled.We were able to determine the optimal PEEP for twelve patients. The ratio of PaO2/FiO2 at inclusion was 131±40 with a mean FiO2 of 71±3%. The optimal PEEP level was lower than the higher PEEP despite a constant increase in SaO2. The optimal PEEP levels varied between 8 and 18 cmH2O.Our results show that in ARDS patients the optimal PEEP differs between each patient and require being determined with monitoring.

  20. Impact of intestinal parasites on haematological parameters of sickle-cell anaemia patients in Nigeria.

    PubMed

    Ahmed, S G; Uraka, J

    2011-09-01

    The majority of patients with sickle-cell anaemia live in the underdeveloped nations where endemic parasitic diseases are prevalent and this may exacerbate the severity of steady-state anaemia in infected patients. We studied the impact of intestinal parasites on haematological parameters of sickle-cell anaemia patients aged 18-35 years in Kano, Nigeria. Of 100 patients studied, 27 were found to be infected with intestinal parasites. There were no significant differences between patients with and without parasitic infections with respect to leukocyte and platelet counts. However, patients without parasitic infections had a significantly higher mean haematocrit than patients with parasitic infections [0.27 L/L (SD 0.03) versus 0.23 (SD 0.03) L/L]. Anaemia in sickle-cell anaemia patients may be exacerbated by intestinal parasites, and these patients should have regular stool examinations for detection and treatment of parasitic infections in order to improve their haematocrit and avoid the risk of blood transfusion.

  1. 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.

  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.

  3. Reductions in immunosuppression after haematological or solid organ cancer diagnosis in kidney transplant recipients.

    PubMed

    Hope, Christopher M; Krige, Alice J; Barratt, Alex; Carroll, Robert P

    2015-11-01

    Few data exist on how immunosuppression is altered in kidney transplant recipients (KTR) following a diagnosis of cancer. This study investigated how immunosuppression was altered in KTR after cancer diagnosis and its effect on patient and graft survival. All KTR diagnosed with cancer at our centre from 1990 to 2012 were assessed. Drug regime and serum creatinine levels were recorded 1 year before, at time of, and 1 year after cancer diagnosis. Of 87 KTR who developed cancer (7.3% of transplanted population, n = 1189), 30 developed haematological malignancies and 57 developed solid organ cancers (SOC). In total, 38% of KTR presented with nodal or metastatic disease and 23 of 87 (26%) KTR died within 6 months of cancer diagnosis. Fifty-five KTR had records of pre- and postcancer diagnosis drug regimes. Thirty-six KTR had a (>50%) dose reduction or cessation of 1 or more immunosuppressive agents, and 19 no reduction in immunosuppression. In total, 2 of 36 (6%) of KTR who underwent a dose reduction suffered acute rejection that was reversed with methylprednisolone. Dose reduction/cessation of immunosuppression did not impair graft function, but also did not affect cancer free survival. Further larger prospective studies are needed to determine whether dose reduction alters relapse free cancer survival in KTR.

  4. 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.

  5. 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

  6. 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

  7. Daily fluctuations of haematology and blood biochemistry in horses fed varying levels of protein.

    PubMed

    Greppi, G F; Casini, L; Gatta, D; Orlandi, M; Pasquini, M

    1996-09-01

    Changes in the plasma biochemistry of 12 stallions were studied over seven 24 h periods. Twelve healthy male horses of 4 different breeds (Thoroughbred [TB], Anglo-Arabo-Sardo [AAS], Avelignese [Av] and Maremmano [M]) were divided into 3 experimental groups and fed with an isoenergetic maintenance ration with different protein levels. The same amount of food was given daily at 0730 and 1930 h. After 20 days of pretrial, a series of 6 blood samples were collected daily from the jugular vein every 4 h for 7 days. The samples were analysed for packed cell volume (PCV), haemoglobin, plasma glucose, free fatty acids, cholesterol, total plasma protein, urea, creatinine, calcium, phosphorus and enzymatic activities: aspartate aminotransferase (AST), alanine aminotrasferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH). The data were analysed following the armonic analysis (Fourier) in order to define the pattern of biorhythm. Many parameters showed a biorhythmical pattern. Protein levels of the diet failed to influence haematology, blood biochemistry and biorhythm. Thoroughbreds showed the highest values of PCV, haemoglobin and creatinine and the lowest total protein, phosphorus and enzymatic activities.

  8. Haematological changes in fluorotic adults and children in fluoride endemic regions of Gaya district, Bihar, India.

    PubMed

    Yasmin, Shahla; Ranjan, Sumeet; D'Souza, Doris

    2014-06-01

    Groundwater used for drinking and cooking was analysed for fluoride (F), and health surveys were conducted in Bodh Gaya, Amas and Bankebazaar blocks of the Gaya district, Bihar, India. Amas and Bankebazaar blocks were F endemic areas with mean F = 2.36 ± 0.23 mg/L (N = 27). Bodh Gaya was considered as control area with mean F = 0.59 ± 0.03 mg/L (N = 11). Health survey showed that more than 50 % of adults and more than 55 % of children had complaints of gastro-intestinal (GI) disturbances in the F endemic areas, while less than 20 % of adults and less than 10 % of children complained of GI problems in the control areas. Haematological analyses were conducted on age- and sex-matched fluorotic subjects (N = 93) of F endemic areas, and non-fluorotic subjects (N = 52) of control area showed lowered haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, and mean corpuscular haemoglobin concentration in the fluorotic subjects, suggesting the occurrence of anaemia in the fluorotic subjects.

  9. 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

  10. Effect of copper deficiency on blood lipid profile and haematological parameters in broilers.

    PubMed

    Kaya, A; Altiner, A; Ozpinar, A

    2006-10-01

    The aim of the study was to observe the changes in haematological parameters and blood lipid profile through copper (Cu) deficiency. Eighty broiler chicks were used in the study. The chicks were separated into two equal groups (n = 40), feed treatment according to the groups started on day 7. The animals in the control group were fed with normal feed. Those in the Cu-deficient group were fed with feed that did not contain supplemental Cu. Blood samples were taken from all the animals on days 7, 21 and 49. Fibrinogen and prothrombin time were assayed in plasma; total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol (LDL-cholesterol), triglyceride and ceruloplasmin were assayed in sera; and haematocrit and thrombocyte levels were assayed in the blood samples. Total cholesterol, triglyceride and LDL-cholesterol levels were significantly higher in the Cu-deficient group than in the control group. Serum ceruloplasmin levels were lower in the Cu-deficient group than in the control group. Prothrombin time was higher in the Cu-deficient group than in the control group. Haematocrit levels were lower in the Cu-deficient group than in the control group. It was concluded that Cu deficiency created hypertriglyceridaemia, hypercholesterolaemia, insufficient growth and anaemia in broilers.

  11. Detection of Legionella Pneumophila in Urine and Serum Specimens of Neutropenic Febrile Patients with Haematological Malignancies

    PubMed Central

    Farzi, Nastaran; Abrehdari-Tafreshi, Zahra; Zarei, Omid; Chamani-Tabriz, Leili

    2017-01-01

    Background: Legionella pneumophila (L. pneumophila) is a gram-negative bacterium which causes ‎Legionnaires’ disease as well as Pontiac fever. The Legionella infections in patients suffering from ‎neutropenia- as a common complication of cancer chemotherapy- can distribute rapidly. We ‎aimed to detect of L. pneumophila in haematological malignancy suffering patients with ‎neutropenic fever by targeting the (macrophage infectivity potentiator) mip gene. Subjects and Methods: Serum and ‎urine specimens were obtained from 80 patients and presence of mip gene of L. pneumophila in ‎specimens was investigated by PCR. Results: The L. pneumophila infection was detected in 21 (26.2%) and 38 ‎‎(47.5%) of urine and serum specimens, respectively. Conclusion: Our findings indicated that the relative high ‎prevalence of L. pneumophila in the studied patients group which show the necessity of ‎considering this microorganism in future studies from detection and treatment point of view in ‎cancer patients. PMID:28286615

  12. [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.

  13. 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

  14. Haematological and Biochemical Morbidity of Schistosoma Haematobium in School Children in Sudan

    PubMed Central

    Mohammed, Elagba HA; Eltayeb, Mohamed; Ibrahim, Hikmat

    2006-01-01

    Objectives: To determine the prevalence and intensity of infection with schistosomiasis among school children and to evaluate the efficacy of praziquantel in normalizing the levels of some haematological and biochemical blood constituents. Methods: A total of 346 school children, aged 7–13 years, from El-Kriab primary school, near the El-Seleit irrigation scheme east of Khartoum, Sudan, were screened for schistosomiasis. All 136 children infected with Schistosoma haematobium and/or S. mansoni were clinically investigated and treated with a single oral dose of praziquantel (40 mg/kg body weight). Results: In 74% out of 97 children infected with S. haematobium the egg count exceeded 500 eggs/10 ml of urine and they had high level of eosinophilia and leukocyte counts, high globulin and calcium levels and low potassium. The serum total proteins, globulins, albumin and urea showed statistically significant differences between control and patients and between patients before and after treatment, although the levels were within the normal reference range. Praziquantel treatment was highly effective as proved by a (58%) cure rate, a (98%) reduction in egg count and normalization of the examined blood parameters six weeks post-treatment. Conclusion: Infection with S. haematobium influenced the normal levels of certain blood constituents and treatment with praziquantel normalized the physiological conditions. According to WHO guidelines, regular mass treatment with praziquantel and health education are recommended as part of the primary health care programme in areas of hight prevalence and intensity of S. haematobium infection. PMID:21748136

  15. 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.

  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. 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

  18. 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.

  19. 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.