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Sample records for remnants fluid membranes

  1. CHARACTERISTICS OF EPIRETINAL MEMBRANE REMNANT EDGE BY OPTICAL COHERENCE TOMOGRAPHY AFTER PARS PLANA VITRECTOMY.

    Science.gov (United States)

    Gaber, Raouf; You, Qi Sheng; Muftuoglu, Ilkay Kilic; Alam, Mostafa; Tsai, Frank F; Mendoza, Nadia; Freeman, William R

    2017-11-01

    To evaluate the incidence, characteristics, and the progression of epiretinal membrane (ERM) remnant edge seen by optical coherence tomography after ERM peeling. A retrospective chart review was conducted for 86 eyes of 85 consecutive patients who were diagnosed with ERM and underwent pars plana vitrectomy for epiretinal membrane peeling between 2013 and 2014. Data collected and analyzed included age, gender, preoperative and postoperative visual acuity, use of indocyanine green dye to stain internal limiting membrane, tamponade used after vitrectomy, ERM edge boundaries, presence of cystoid macular edema, and central foveal thickness. An ERM remnant edge was detected in 33/86 study eyes (38.4%) at the first postoperative optical coherence tomography scan. Compared with those without an ERM remnant, patients with an ERM remnant after surgery were significantly older at baseline and had a higher incidence of ERM recurrence at their last visit. They were not significantly different in terms of gender, preoperative and postoperative visual acuity, reduction of central foveal thickness from baseline, proportion of eyes with preoperative ERM elevation on optical coherence tomography, presence of macular edema before surgery, intraoperative use of indocyanine green staining for ILM peeling, or tamponade used. Based on the edge morphology, we classified the ERM remnant into three types: Type 1 was flat and blended with the retina (14/33 eyes, 42.4%), Type 2 was flat but stepped (17/33 eyes, 51.5%), and Type 3 was elevated (2/33 eyes, 6.0%). A significantly higher risk of ERM recurrence was seen in Type 2 and Type 3 ERM remnants (75% and 100%, respectively) than Type 1 ERM remnants (10%). An ERM remnant edge was detected by optical coherence tomography after ERM peeling in 38.4% of eyes. The presence of a postoperative ERM edge was associated with a higher risk of ERM recurrence, particularly in Type 2 and Type 3 ERM remnants.

  2. Immobilized fluid membranes for gas separation

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

    2014-03-18

    Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

  3. Fuel cell membrane hydration and fluid metering

    Science.gov (United States)

    Jones, Daniel O.; Walsh, Michael M.

    1999-01-01

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  4. Hamilton's equations for a fluid membrane

    International Nuclear Information System (INIS)

    Capovilla, R; Guven, J; Rojas, E

    2005-01-01

    Consider a homogeneous fluid membrane described by the Helfrich-Canham energy, quadratic in the mean curvature of the membrane surface. The shape equation that determines equilibrium configurations is fourth order in derivatives and cubic in the mean curvature. We introduce a Hamiltonian formulation of this equation which dismantles it into a set of coupled first-order equations. This involves interpreting the Helfrich-Canham energy as an action; equilibrium surfaces are generated by the evolution of space curves. Two features complicate the implementation of a Hamiltonian framework. (i) The action involves second derivatives. This requires treating the velocity as a phase-space variable and the introduction of its conjugate momentum. The canonical Hamiltonian is constructed on this phase space. (ii) The action possesses a local symmetry-reparametrization invariance. The two labels we use to parametrize points on the surface are themselves physically irrelevant. This symmetry implies primary constraints, one for each label, that need to be implemented within the Hamiltonian. The two Lagrange multipliers associated with these constraints are identified as the components of the acceleration tangential to the surface. The conservation of the primary constraints implies two secondary constraints, fixing the tangential components of the momentum conjugate to the position. Hamilton's equations are derived and the appropriate initial conditions on the phase-space variables are identified. Finally, it is shown how the shape equation can be reconstructed from these equations

  5. Organic fluid permeation through fluoropolymer membranes

    Science.gov (United States)

    Nemser, Stuart M.; Kosaraju, Praveen; Bowser, John

    2015-07-14

    Separation of the components of liquid mixtures is achieved by contacting a liquid mixture with a nonporous membrane having a fluoropolymer selectively permeable layer and imposing a pressure gradient across the membrane from feed side to permeate side. Unusually high transmembrane flux is obtained when the membrane is subjected to one or more process conditions prior to separation. These include (a) leaving some residual amount of membrane casting solvent in the membrane, and (b) contacting the membrane with a component of the mixture to be separated for a duration effective to saturate the membrane with the component.

  6. Intrauterine Defensive Mechanism of Amniotic Fluid and Fetal Membranes

    OpenAIRE

    金山, 尚裕

    1994-01-01

    To determine the intrauterine defensive role of urinary trypsin inhibitor (UTI), we studied the effects of UTI in amniotic fluid, fetal membranes and myometrium. The level of UTI was 94±34U/ml in neonatal urine (compared to adult urine 8.0±6.0U/ml) and 88±37U/ml in amniotic fluid. This may indicate that the main source of UTI in the amniotic fluid is the fetal urine. UTI was found to be concentrated in vernix, fetal intestine, amniotic membranes and uterine myometrium. Immunostaining of term ...

  7. Remnant lipoproteins

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G.

    2017-01-01

    Purpose of review: To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. Recent findings: In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined...... of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way....

  8. Fluid transportation mechanisms by a coupled system of elastic membranes and magnetic fluids

    International Nuclear Information System (INIS)

    Ido, Y.; Tanaka, K.; Sugiura, Y.

    2002-01-01

    The basic properties of the fluid transportation mechanism that is produced by the coupled waves propagating along a thin elastic membrane covering a magnetic fluid layer in a shallow and long rectangular vessel are investigated. It is shown that the progressive magnetic field induced by the rectangular pulses generates sinusoidal vibration of the displacement of elastic membrane and makes the system work more efficiently than the magnetic field induced by the pulse-width-modulation method

  9. Mechanical collapse of confined fluid membrane vesicles.

    Science.gov (United States)

    Rim, Jee E; Purohit, Prashant K; Klug, William S

    2014-11-01

    Compact cylindrical and spherical invaginations are common structural motifs found in cellular and developmental biology. To understand the basic physical mechanisms that produce and maintain such structures, we present here a simple model of vesicles in confinement, in which mechanical equilibrium configurations are computed by energy minimization, balancing the effects of curvature elasticity, contact of the membrane with itself and the confining geometry, and adhesion. For cylindrical confinement, the shape equations are solved both analytically and numerically by finite element analysis. For spherical confinement, axisymmetric configurations are obtained numerically. We find that the geometry of invaginations is controlled by a dimensionless ratio of the adhesion strength to the bending energy of an equal area spherical vesicle. Larger adhesion produces more concentrated curvatures, which are mainly localized to the "neck" region where the invagination breaks away from its confining container. Under spherical confinement, axisymmetric invaginations are approximately spherical. For extreme confinement, multiple invaginations may form, bifurcating along multiple equilibrium branches. The results of the model are useful for understanding the physical mechanisms controlling the structure of lipid membranes of cells and their organelles, and developing tissue membranes.

  10. A numerical method for interaction problems between fluid and membranes with arbitrary permeability for fluid

    Science.gov (United States)

    Miyauchi, Suguru; Takeuchi, Shintaro; Kajishima, Takeo

    2017-09-01

    We develop a numerical method for fluid-membrane interaction accounting for permeation of the fluid using a non-conforming mesh to the membrane shape. To represent the permeation flux correctly, the proposed finite element discretization incorporates the discontinuities in the velocity gradient and pressure on the membrane surface with specially selected base functions. The discontinuities are represented with independent variables and determined to satisfy the governing equations including the interfacial condition on the permeation. The motions of the fluid, membrane and permeation flux are coupled monolithically and time-advanced fully-implicitly. The validity and effectiveness of the proposed method are demonstrated by several two-dimensional fluid-membrane interaction problems of Stokes flows by comparing with the analytical models and numerical results obtained by other methods. The reproduced sharp discontinuities are found to be essential to suppress the non-physical permeation flux. Further, combined with the numerical treatment for the solute concentration across the membrane, the proposed method is applied to a fluid-structure interaction problem including the osmotic pressure difference.

  11. Radioiodine remnant ablation of differentiated thyroid cancer does not further increase oxidative damage to membrane lipids - early effect

    Directory of Open Access Journals (Sweden)

    Makarewicz Jacek

    2010-10-01

    Full Text Available Abstract Introduction Radioiodine (131I therapy is widely accepted as an essential part of therapeutic regimens in many cases of differentiated thyroid cancer. Radiation-induced oxidative damage to macromolecules is a well known phenomenon. Frequently examined process to evaluate oxidative damage to macromolecules is lipid peroxidation (LPO, resulting from oxidative damage to membrane lipids. The aim of the study was to examine serum LPO level in hypothyroid (after total thyroidectomy cancer patients subjected to ablative activities of 131I. Materials and methods The study was carried out in 21 patients (18 females and 3 males, average age 52.4 ± 16.5 years after total thyroidectomy for papillary (17 patients or follicular (4 patients thyroid carcinoma. Hypothyroidism was confirmed by increased TSH blood concentration (BRAHMS, Germany, measured before 131I therapy. Activity of 2.8 - 6.9 GBq of 131I was administered to the patients orally as sodium iodide (OBRI, Poland. Concentrations of malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA, as an index of LPO (LPO-586 kit, Calbiochem, USA, were measured in blood serum just before 131I administration (day "0" and on the days 1-4 after 131I therapy. Sera from 23 euthyroid patients served as controls. Correlations between LPO and TSH or 131I activity were calculated. Results Expectedly, serum LPO level, when measured before 131I therapy, was several times higher (p 131I therapy. LPO did not correlate with TSH concentration. In turn, negative correlation was found between 131I activity and LPO level on the day "2" after radioiodine treatment. Conclusions Radioiodine remnant ablation of differentiated thyroid cancer does not further increase oxidative damage to membrane lipids, at least early, after therapy.

  12. Dynamics of fluid lines, sheets, filaments and membranes

    International Nuclear Information System (INIS)

    Coutris, N.

    1988-01-01

    We establish the dynamic equations of two types of fluid structures: 1) lines-filaments and 2) sheets-membranes. In the first part, we consider one-dimensional (line) and two-dimensional (sheet) fluid structures. The second part concerns the associated three- dimensional structures: filaments and membranes. In the third part, we establish the equations for thickened lines and thickened sheets. For that purpose, we introduce a thickness in the models of the first part. The fourth part concerns the thinning of the filament and the membrane. Then, by an asymptotic process, we deduce the corresponding equations from the equations of the second part in order to show the purely formal equivalence of the equations of the third and fourth parts. To obtain the equations, we make use of theorems whose proofs can be found in the appendices. The equations can be applied to many areas of interest: instabilities of liquid jets and liquid films, modelisation of interfaces between two different fluids as sheets or membranes, modelisation with the averaged equations over a cross section of single phase flows and two-phase flows in channels with a nonrectilinear axis such as bends or pump casings [fr

  13. High-flux membrane separation using fluid skimming dominated convective fluid flow

    NARCIS (Netherlands)

    Dinther, van A.M.C.; Schroën, C.G.P.H.; Boom, R.M.

    2011-01-01

    We here report on the separation of yeast cells, with micro-engineered membranes having pores that are typically five times larger than the cells. The separation is due to neither shear-induced diffusion, nor initial lift, but to an effect similar to fluid skimming. The separation performance is

  14. Raised Vaginal Fluid Fibronectin Level Indicates Premature Rupture of Membrane

    Directory of Open Access Journals (Sweden)

    Amrita Bhowmik

    2012-07-01

    Full Text Available Background: Premature rupture of membrane (PROM is one of the common complications of pregnancy that has major impact on fetal and neonatal outcome. It is the commonest clinical event where a normal pregnancy becomes suddenly a high-risk one for mother and fetus or neonate. Objective: The study was undertaken to investigate whether raised fibronectin level in vaginal fluid may indicate premature rupture of membrane. Materials and Methods: This cross sectional study was conducted in the department of Obstetrics and Gynecology in Sir Salimullah Medical College & Mitford Hospital, Dhaka during the period of January 2006 to December 2007. A total of 114 pregnant women with gestational age 28th week up to 40th week were included. Sixty were PROM (Group I and 54 were non-PROM (Group II subjects. Fibronectin in vaginal fluid was measured by an immunochemical reaction by nephelometer. Statistical analysis was done by SPSS version 10.0. Results: The PROM patients had significantly higher concentration of fibronectin (225.77 ± 115.18 ng/mL compared to that in non-PROM subjects (8.04 ± 16.17 ng/mL (p < 0.001. Conclusion: It can be concluded that in cases of unequivocal rupture or intactness of the membranes, the result of the fibronectin test corresponds well with the clinical situation. So fibronectin is a sensitive test for detection of amniotic fluid in the vagina.

  15. Remnant lipoproteins.

    Science.gov (United States)

    Varbo, Anette; Nordestgaard, Børge G

    2017-08-01

    To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined in different ways) to be involved in atherosclerosis development and cardiovascular disease risk. High concentrations of remnant cholesterol could explain some of the residual risk of cardiovascular disease seen after LDL cholesterol lowering. This will be increasingly important as populations worldwide become more obese and more have diabetes, both of which elevate remnant cholesterol concentrations. Many smaller scale studies and post hoc analyses show that remnant cholesterol can be lowered by different types of drugs; however, results from large scale studies with the primary aim of reducing cardiovascular disease risk through lowering of remnant cholesterol in individuals with elevated concentrations are still missing, although some are under way. Remnant cholesterol is a risk factor for cardiovascular disease, and can be lowered by different types of drugs; however, large scale studies of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way.

  16. Ethylene glycol as bore fluid for hollow fiber membrane preparation

    KAUST Repository

    Le, Ngoc Lieu

    2017-03-31

    We proposed the use of ethylene glycol and its mixture with water as bore fluid for the preparation of poly(ether imide) (PEI) hollow fiber membranes and compared their performance and morphology with membranes obtained with conventional coagulants (water and its mixture with the solvent N-methylpyrrolidone (NMP)). Thermodynamics and kinetics of the systems were investigated. Water and 1:1 water:EG mixtures lead to fast precipitation rates. Slow precipitation is observed for both pure EG and 9:1 NMP:water mixture, but the reasons for that are different. While low osmotic driving force leads to slow NMP and water transport when NMP:water is used, the high EG viscosity is the reason for the slow phase separation when EG is the bore fluid. The NMP:water mixture produces fibers with mixed sponge-like and finger-like structure with large pores in the inner and outer layers; and hence leading to a high water permeance and a high MWCO suitable for separation of large-sized proteins. As compared to NMP:water, using EG as bore fluid provides fibers with a finger-like bilayered structure and sponge-like layers near the surfaces, and hence contributing to the higher water permeance. It also induces small pores for better protein rejection.

  17. Ethylene glycol as bore fluid for hollow fiber membrane preparation

    KAUST Repository

    Le, Ngoc Lieu; Nunes, Suzana Pereira

    2017-01-01

    We proposed the use of ethylene glycol and its mixture with water as bore fluid for the preparation of poly(ether imide) (PEI) hollow fiber membranes and compared their performance and morphology with membranes obtained with conventional coagulants (water and its mixture with the solvent N-methylpyrrolidone (NMP)). Thermodynamics and kinetics of the systems were investigated. Water and 1:1 water:EG mixtures lead to fast precipitation rates. Slow precipitation is observed for both pure EG and 9:1 NMP:water mixture, but the reasons for that are different. While low osmotic driving force leads to slow NMP and water transport when NMP:water is used, the high EG viscosity is the reason for the slow phase separation when EG is the bore fluid. The NMP:water mixture produces fibers with mixed sponge-like and finger-like structure with large pores in the inner and outer layers; and hence leading to a high water permeance and a high MWCO suitable for separation of large-sized proteins. As compared to NMP:water, using EG as bore fluid provides fibers with a finger-like bilayered structure and sponge-like layers near the surfaces, and hence contributing to the higher water permeance. It also induces small pores for better protein rejection.

  18. Hamilton's equations for a fluid membrane: axial symmetry

    International Nuclear Information System (INIS)

    Capovilla, R; Guven, J; Rojas, E

    2005-01-01

    Consider a homogeneous fluid membrane, or vesicle, described by the Helfrich-Canham energy, quadratic in the mean curvature. When the membrane is axially symmetric, this energy can be viewed as an 'action' describing the motion of a particle; the contours of equilibrium geometries are identified with particle trajectories. A novel Hamiltonian formulation of the problem is presented which exhibits the following two features: (i) the second derivatives appearing in the action through the mean curvature are accommodated in a natural phase space and (ii) the intrinsic freedom associated with the choice of evolution parameter along the contour is preserved. As a result, the phase space involves momenta conjugate not only to the particle position but also to its velocity, and there are constraints on the phase space variables. This formulation provides the groundwork for a field theoretical generalization to arbitrary configurations, with the particle replaced by a loop in space

  19. Instabilities and diffusion in a hydrodynamic model of a fluid membrane coupled to a thin active fluid layer.

    Science.gov (United States)

    Sarkar, N; Basu, A

    2012-11-01

    We construct a coarse-grained effective two-dimensional (2d hydrodynamic theory as a theoretical model for a coupled system of a fluid membrane and a thin layer of a polar active fluid in its ordered state that is anchored to the membrane. We show that such a system is prone to generic instabilities through the interplay of nonequilibrium drive, polar order and membrane fluctuation. We use our model equations to calculate diffusion coefficients of an inclusion in the membrane and show that their values depend strongly on the system size, in contrast to their equilibrium values. Our work extends the work of S. Sankararaman and S. Ramaswamy (Phys. Rev. Lett., 102, 118107 (2009)) to a coupled system of a fluid membrane and an ordered active fluid layer. Our model is broadly inspired by and should be useful as a starting point for theoretical descriptions of the coupled dynamics of a cell membrane and a cortical actin layer anchored to it.

  20. Fluid Mechanics of the Vascular Basement Membrane in the Brain

    Science.gov (United States)

    Coloma, Mikhail; Hui, Jonathan; Chiarot, Paul; Huang, Peter; Carare, Roxana; McLeod, Kenneth; Schaffer, David

    2013-11-01

    Beta-amyloid is a normal product of brain metabolic function and is found within the interstitial fluid of the brain. Failure of the clearance of beta-amyloid from the aging brain leads to its accumulation within the walls of arteries and to Alzheimer's disease. The vascular basement membrane (VBM) within the walls of cerebral arteries surrounds the spirally arranged smooth muscle cells and represents an essential pathway for removal of beta-amyloid from the brain. This process fails with the stiffening of arterial walls associated with aging. In this study we hypothesize that the deformation of the VBM associated with arterial pulsations drives the interstitial fluid to drain in the direction opposite of the arterial blood flow. This hypothesis is theoretically investigated by modeling the VBM as a thin, coaxial, fluid-filled porous medium surrounding a periodically deforming cylindrical tube. Flow and boundary conditions required to achieve such a backward clearance are derived through a control volume analysis of mass, momentum, and energy.

  1. Hamilton's equations for a fluid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Capovilla, R [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados, Apdo. Postal 14-740, 07000 Mexico, DF (Mexico); Guven, J [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apdo. Postal 70-543, 04510 Mexico, DF (Mexico); Rojas, E [Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)

    2005-10-14

    Consider a homogeneous fluid membrane described by the Helfrich-Canham energy, quadratic in the mean curvature of the membrane surface. The shape equation that determines equilibrium configurations is fourth order in derivatives and cubic in the mean curvature. We introduce a Hamiltonian formulation of this equation which dismantles it into a set of coupled first-order equations. This involves interpreting the Helfrich-Canham energy as an action; equilibrium surfaces are generated by the evolution of space curves. Two features complicate the implementation of a Hamiltonian framework. (i) The action involves second derivatives. This requires treating the velocity as a phase-space variable and the introduction of its conjugate momentum. The canonical Hamiltonian is constructed on this phase space. (ii) The action possesses a local symmetry-reparametrization invariance. The two labels we use to parametrize points on the surface are themselves physically irrelevant. This symmetry implies primary constraints, one for each label, that need to be implemented within the Hamiltonian. The two Lagrange multipliers associated with these constraints are identified as the components of the acceleration tangential to the surface. The conservation of the primary constraints implies two secondary constraints, fixing the tangential components of the momentum conjugate to the position. Hamilton's equations are derived and the appropriate initial conditions on the phase-space variables are identified. Finally, it is shown how the shape equation can be reconstructed from these equations.

  2. Absence of first-order unbinding transitions of fluid and polymerized membranes

    Science.gov (United States)

    Grotehans, Stefan; Lipowsky, Reinhard

    1990-01-01

    Unbinding transitions of fluid and polymerized membranes are studied by renormalization-group (RG) methods. Two different RG schemes are used and found to give rather consistent results. The fixed-point structure of both RG's exhibits a complex behavior as a function of the decay exponent tau for the fluctuation-induced interaction of the membranes. For tau greater than tau(S2) interacting membranes can undergo first-order transitions even in the strong-fluctuation regime. These estimates for tau(S2) imply, however, that both fluid and polymerized membranes unbind in a continuous way in the absence of lateral tension.

  3. A general theory of non-equilibrium dynamics of lipid-protein fluid membranes

    DEFF Research Database (Denmark)

    Lomholt, Michael Andersen; Hansen, Per Lyngs; Miao, L.

    2005-01-01

    We present a general and systematic theory of non-equilibrium dynamics of multi-component fluid membranes, in general, and membranes containing transmembrane proteins, in particular. Developed based on a minimal number of principles of statistical physics and designed to be a meso...

  4. The homeodomain derived peptide Penetratin induces curvature of fluid membrane domains.

    Directory of Open Access Journals (Sweden)

    Antonin Lamazière

    Full Text Available BACKGROUND: Protein membrane transduction domains that are able to cross the plasma membrane are present in several transcription factors, such as the homeodomain proteins and the viral proteins such as Tat of HIV-1. Their discovery resulted in both new concepts on the cell communication during development, and the conception of cell penetrating peptide vectors for internalisation of active molecules into cells. A promising cell penetrating peptide is Penetratin, which crosses the cell membranes by a receptor and metabolic energy-independent mechanism. Recent works have claimed that Penetratin and similar peptides are internalized by endocytosis, but other endocytosis-independent mechanisms have been proposed. Endosomes or plasma membranes crossing mechanisms are not well understood. Previously, we have shown that basic peptides induce membrane invaginations suggesting a new mechanism for uptake, "physical endocytosis". METHODOLOGY/PRINCIPAL FINDINGS: Herein, we investigate the role of membrane lipid phases on Penetratin induced membrane deformations (liquid ordered such as in "raft" microdomains versus disordered fluid "non-raft" domains in membrane models. Experimental data show that zwitterionic lipid headgroups take part in the interaction with Penetratin suggesting that the external leaflet lipids of cells plasma membrane are competent for peptide interaction in the absence of net negative charges. NMR and X-ray diffraction data show that the membrane perturbations (tubulation and vesiculation are associated with an increase in membrane negative curvature. These effects on curvature were observed in the liquid disordered but not in the liquid ordered (raft-like membrane domains. CONCLUSIONS/SIGNIFICANCE: The better understanding of the internalisation mechanisms of protein transduction domains will help both the understanding of the mechanisms of cell communication and the development of potential therapeutic molecular vectors. Here we

  5. Fluid-membrane tethers: minimal surfaces and elastic boundary layers.

    Science.gov (United States)

    Powers, Thomas R; Huber, Greg; Goldstein, Raymond E

    2002-04-01

    Thin cylindrical tethers are common lipid bilayer membrane structures, arising in situations ranging from micromanipulation experiments on artificial vesicles to the dynamic structure of the Golgi apparatus. We study the shape and formation of a tether in terms of the classical soap-film problem, which is applied to the case of a membrane disk under tension subject to a point force. A tether forms from the elastic boundary layer near the point of application of the force, for sufficiently large displacement. Analytic results for various aspects of the membrane shape are given.

  6. Two-component fluid membranes near repulsive walls: Linearized hydrodynamics of equilibrium and nonequilibrium states.

    Science.gov (United States)

    Sankararaman, Sumithra; Menon, Gautam I; Sunil Kumar, P B

    2002-09-01

    We study the linearized hydrodynamics of a two-component fluid membrane near a repulsive wall, using a model that incorporates curvature-concentration coupling as well as hydrodynamic interactions. This model is a simplified version of a recently proposed one [J.-B. Manneville et al., Phys. Rev. E 64, 021908 (2001)] for nonequilibrium force centers embedded in fluid membranes, such as light-activated bacteriorhodopsin pumps incorporated in phospholipid egg phosphatidyl choline (EPC) bilayers. The pump-membrane system is modeled as an impermeable, two-component bilayer fluid membrane in the presence of an ambient solvent, in which one component, representing active pumps, is described in terms of force dipoles displaced with respect to the bilayer midpoint. We first discuss the case in which such pumps are rendered inactive, computing the mode structure in the bulk as well as the modification of hydrodynamic properties by the presence of a nearby wall. These results should apply, more generally, to equilibrium fluid membranes comprised of two components, in which the effects of curvature-concentration coupling are significant, above the threshold for phase separation. We then discuss the fluctuations and mode structure in the steady state of active two-component membranes near a repulsive wall. We find that proximity to the wall smoothens membrane height fluctuations in the stable regime, resulting in a logarithmic scaling of the roughness even for initially tensionless membranes. This explicitly nonequilibrium result is a consequence of the incorporation of curvature-concentration coupling in our hydrodynamic treatment. This result also indicates that earlier scaling arguments which obtained an increase in the roughness of active membranes near repulsive walls upon neglecting the role played by such couplings may need to be reevaluated.

  7. Electrochemically deposited and etched membranes with precisely sized micropores for biological fluids microfiltration

    International Nuclear Information System (INIS)

    Hamzah, A A; Zainal Abidin, H E; Yeop Majlis, B; Mohd Nor, M; Ismardi, A; Sugandi, G; Tiong, T Y; Dee, C F; Yunas, J

    2013-01-01

    This paper presents simple and economical, yet reliable techniques to fabricate a micro-fluidic filter for MEMS lab-on-chip (LoC) applications. The microporous filter is a crucial component in a MEMS LoC system. Microsized components and contaminants in biological fluids are selectively filtered using copper and silicon membranes with precisely controlled microsized pores. Two techniques were explored in microporous membrane fabrication, namely copper electroplating and electrochemical etching (ECE) of silicon. In the first technique, a copper membrane with evenly distributed micropores was fabricated by electroplating the copper layer on the silicon nitride membrane, which was later removed to leave the freestanding microporous membrane structure. The second approach involves the thinning of bulk silicon down to a few micrometers thick using KOH and etching the resulting silicon membrane in 5% HF by ECE to create micropores. Upon testing with nanoparticles of various sizes, it was observed that electroplated copper membrane passes nanoparticles up to 200 nm wide, while porous silicon membrane passes nanoparticles up to 380 nm in size. Due to process compatibility, simplicity, and low-cost fabrication, electroplated copper and porous silicon membranes enable synchronized microfilter fabrication and integration into the MEMS LoC system. (paper)

  8. Biophysical properties of membrane lipids of anammox bacteria : I. Ladderane phospholipids form highly organized fluid membranes

    NARCIS (Netherlands)

    Boumann, Henry A.; Longo, Marjorie L.; Stroeve, Pieter; Poolman, Bert; Hopmans, Ellen C.; Stuart, Marc C. A.; Damste, Jaap S. Sinninghe; Schouten, Stefan

    Anammox bacteria that are capable of anaerobically oxidizing ammonium (anammox) with nitrite to nitrogen gas produce unique membrane phospholipids that comprise hydrocarbon chains with three or five linearly condensed cyclobutane rings. To gain insight into the biophysical properties of these

  9. Drug binding and mobility relating to the thermal fluctuation in fluid lipid membranes

    Science.gov (United States)

    Okamura, Emiko; Yoshii, Noriyuki

    2008-12-01

    Drug binding and mobility in fluid lipid bilayer membranes are quantified in situ by using the multinuclear solution NMR combined with the pulsed-field-gradient technique. One-dimensional and pulsed-field-gradient F19 and H1 NMR signals of an anticancer drug, 5-fluorouracil (5FU) are analyzed at 283-313 K in the presence of large unilamellar vesicles (LUVs) of egg phosphatidylcholine (EPC) as model cell membranes. The simultaneous observation of the membrane-bound and free 5FU signals enables to quantify in what amount of 5FU is bound to the membrane and how fast 5FU is moving within the membrane in relation to the thermal fluctuation of the soft, fluid environment. It is shown that the mobility of membrane-bound 5FU is slowed down by almost two orders of magnitude and similar to the lipid movement in the membrane, the movement closely related to the intramembrane fluidity. The mobility of 5FU and EPC is, however, not similar at 313 K; the 5FU movement is enhanced in the membrane as a result of the loose binding of 5FU in the lipid matrices. The membrane-bound fraction of 5FU is ˜0.1 and almost unaltered over the temperature range examined. It is also independent of the 5FU concentration from 2 to 30 mM with respect to the 40-50 mM LUV. The free energy of the 5FU binding is estimated at -4 to -2 kJ/mol, the magnitude always close to the thermal fluctuation, 2.4-2.6 kJ/mol.

  10. Vascular basement membranes as pathways for the passage of fluid into and out of the brain.

    Science.gov (United States)

    Morris, Alan W J; Sharp, Matthew MacGregor; Albargothy, Nazira J; Fernandes, Rute; Hawkes, Cheryl A; Verma, Ajay; Weller, Roy O; Carare, Roxana O

    2016-05-01

    In the absence of conventional lymphatics, drainage of interstitial fluid and solutes from the brain parenchyma to cervical lymph nodes is along basement membranes in the walls of cerebral capillaries and tunica media of arteries. Perivascular pathways are also involved in the entry of CSF into the brain by the convective influx/glymphatic system. The objective of this study is to differentiate the cerebral vascular basement membrane pathways by which fluid passes out of the brain from the pathway by which CSF enters the brain. Experiment 1: 0.5 µl of soluble biotinylated or fluorescent Aβ, or 1 µl 15 nm gold nanoparticles was injected into the mouse hippocampus and their distributions determined at 5 min by transmission electron microscopy. Aβ was distributed within the extracellular spaces of the hippocampus and within basement membranes of capillaries and tunica media of arteries. Nanoparticles did not enter capillary basement membranes from the extracellular spaces. Experiment 2: 2 µl of 15 nm nanoparticles were injected into mouse CSF. Within 5 min, groups of nanoparticles were present in the pial-glial basement membrane on the outer aspect of cortical arteries between the investing layer of pia mater and the glia limitans. The results of this study and previous research suggest that cerebral vascular basement membranes form the pathways by which fluid passes into and out of the brain but that different basement membrane layers are involved. The significance of these findings for neuroimmunology, Alzheimer's disease, drug delivery to the brain and the concept of the Virchow-Robin space are discussed.

  11. Development of modifications to the material point method for the simulation of thin membranes, compressible fluids, and their interactions

    Energy Technology Data Exchange (ETDEWEB)

    York, A.R. II [Sandia National Labs., Albuquerque, NM (United States). Engineering and Process Dept.

    1997-07-01

    The material point method (MPM) is an evolution of the particle in cell method where Lagrangian particles or material points are used to discretize the volume of a material. The particles carry properties such as mass, velocity, stress, and strain and move through a Eulerian or spatial mesh. The momentum equation is solved on the Eulerian mesh. Modifications to the material point method are developed that allow the simulation of thin membranes, compressible fluids, and their dynamic interactions. A single layer of material points through the thickness is used to represent a membrane. The constitutive equation for the membrane is applied in the local coordinate system of each material point. Validation problems are presented and numerical convergence is demonstrated. Fluid simulation is achieved by implementing a constitutive equation for a compressible, viscous, Newtonian fluid and by solution of the energy equation. The fluid formulation is validated by simulating a traveling shock wave in a compressible fluid. Interactions of the fluid and membrane are handled naturally with the method. The fluid and membrane communicate through the Eulerian grid on which forces are calculated due to the fluid and membrane stress states. Validation problems include simulating a projectile impacting an inflated airbag. In some impact simulations with the MPM, bodies may tend to stick together when separating. Several algorithms are proposed and tested that allow bodies to separate from each other after impact. In addition, several methods are investigated to determine the local coordinate system of a membrane material point without relying upon connectivity data.

  12. Computational fluid dynamics simulations of membrane filtration process adapted for water treatment of aerated sewage lagoons.

    Science.gov (United States)

    Cano, Grégory; Mouahid, Adil; Carretier, Emilie; Guasp, Pascal; Dhaler, Didier; Castelas, Bernard; Moulin, Philippe

    2015-01-01

    The aim of this study is to apply the membrane bioreactor technology in an oxidation ditch in submerged conditions. This new wastewater filtration process will benefit rural areas (membranes developed without support are immersed in an aeration well and work in suction mode. The development of the membrane without support and more precisely the performance of spacers are approached by computational fluid dynamics in order to provide the best compromise between pressure drop/flow velocity and permeate flux. The numerical results on the layout and the membrane modules' geometry in the aeration well indicate that the optimal configuration is to install the membranes horizontally on three levels. Membranes should be connected to each other to a manifold providing a total membrane area of 18 m². Loss rate compared to the theoretical throughput is relatively low (less than 3%). Preliminary data obtained by modeling the lagoon provide access to its hydrodynamics, revealing that recirculation zones can be optimized by making changes in the operating conditions. The experimental validation of these results and taking into account the aeration in the numerical models are underway.

  13. The Balance of Fluid and Osmotic Pressures across Active Biological Membranes with Application to the Corneal Endothelium.

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    Full Text Available The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Katchalsky (KK equations is proposed to describe fluxes of water and solutes across biological membranes, and is applied to analyze the relationship between fluid and osmotic pressures, accounting for active transport mechanisms that propel substances against their concentration gradients and for fixed charges that alter ionic distributions in separated environments. The equilibrium analysis demonstrates that the proposed theory recovers the Donnan osmotic pressure and can predict the correct fluid pressure difference across membranes, a result which cannot be achieved by existing KK theories due to the neglect of fixed charges. The steady-state analysis on active membranes suggests a new pressure mechanism which balances the fluid pressure together with the osmotic pressure. The source of this pressure arises from active ionic fluxes and from interactions between solvent and solutes in membrane transport. We apply the proposed theory to study the transendothelial fluid pressure in the in vivo cornea, which is a crucial factor maintaining the hydration and transparency of the tissue. The results show the importance of the proposed pressure mechanism in mediating stromal fluid pressure and provide a new interpretation of the pressure modulation mechanism in the in vivo cornea.

  14. Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation

    Science.gov (United States)

    Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica

    2015-12-22

    Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

  15. The diagnostic value of the lactate concentration in the vaginal fluid for diagnosis of premature rupture of membranes

    Directory of Open Access Journals (Sweden)

    N Nazari

    2013-11-01

    Conclusion: Test of Lactate concentration in vaginal fluid test is a valid, quick and easy with high sensitivity and specificity for the diagnosis of premature rupture of membranes the fetus of pregnant women.

  16. Remnant lipoproteins and atherosclerosis

    NARCIS (Netherlands)

    Twickler, Th. B.; Dallinga-Thie, G. M.; Chapman, M. J.; Cohn, J. S.

    2005-01-01

    A recently developed assay for quantification of remnant-like particle cholesterol has provided considerable evidence that reinforces the concept that elevated levels of plasma remnants are associated with increased cardiovascular disease in different populations and distinct patient groups. In this

  17. Co-existence of Gel and Fluid Lipid Domains in Single-component Phospholipid Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Clare L [McMaster University; Barrett, M [McMaster University; Toppozini, L [McMaster University; Yamani, Zahra [Canadian Neutron Beam Centre, National Research Council, Chalk River Laboratorie; Kucerka, Norbert [Canadian Neutron Beam Centre and Comelius University (Slovakia); Katsaras, John [ORNL; Fragneto, Giovanna [Institut Laue-Langevin (ILL); Rheinstadter, Maikel C [McMaster University

    2012-01-01

    Lateral nanostructures in membranes, so-called rafts, are believed to strongly influence membrane properties and functions. The experimental observation of rafts has proven difficult as they are thought to be dynamic structures that likely fluctuate on nano- to microsecond time scales. Using neutron diffraction we present direct experimental evidence for the co-existence of gel and fluid lipid domains in a single-component phospholipid membrane made of DPPC as it undergoes its main phase transition. The coherence length of the neutron beam sets a lower limit for the size of structures that can be observed. Neutron coherence lengths between 30 and 242A used in this study were obtained by varying the incident neutron energy and the resolution of the neutron spectrometer. We observe Bragg peaks corresponding to co-existing nanometer sized structures, both in out-of-plane and in-plane scans, by tuning the neutron coherence length. During the main phase transition, instead of a continuous transition that shows a pseudo-critical behavior, we observe the co-existence of gel and fluid domains.

  18. A Fluid Membrane-Based Soluble Ligand Display System for Live CellAssays

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jwa-Min; Nair, Pradeep N.; Neve, Richard M.; Gray, Joe W.; Groves, Jay T.

    2005-10-14

    Cell communication modulates numerous biological processes including proliferation, apoptosis, motility, invasion and differentiation. Correspondingly, there has been significant interest in the development of surface display strategies for the presentation of signaling molecules to living cells. This effort has primarily focused on naturally surface-bound ligands, such as extracellular matrix components and cell membranes. Soluble ligands (e.g. growth factors and cytokines) play an important role in intercellular communications, and their display in a surface-bound format would be of great utility in the design of array-based live cell assays. Recently, several cell microarray systems that display cDNA, RNAi, or small molecules in a surface array format were proven to be useful in accelerating high-throughput functional genetic studies and screening therapeutic agents. These surface display methods provide a flexible platform for the systematic, combinatorial investigation of genes and small molecules affecting cellular processes and phenotypes of interest. In an analogous sense, it would be an important advance if one could display soluble signaling ligands in a surface assay format that allows for systematic, patterned presentation of soluble ligands to live cells. Such a technique would make it possible to examine cellular phenotypes of interest in a parallel format with soluble signaling ligands as one of the display parameters. Herein we report a ligand-modified fluid supported lipid bilayer (SLB) assay system that can be used to functionally display soluble ligands to cells in situ (Figure 1A). By displaying soluble ligands on a SLB surface, both solution behavior (the ability to become locally enriched by reaction-diffusion processes) and solid behavior (the ability to control the spatial location of the ligands in an open system) could be combined. The method reported herein benefits from the naturally fluid state of the supported membrane, which allows

  19. Hamilton's equations for a fluid membrane: axial symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Capovilla, R [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, Apdo Postal 14-740, 07000 Mexico, DF (Mexico); Guven, J [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apdo Postal 70-543, 04510 Mexico, DF (Mexico); Rojas, E [Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)

    2005-09-23

    Consider a homogeneous fluid membrane, or vesicle, described by the Helfrich-Canham energy, quadratic in the mean curvature. When the membrane is axially symmetric, this energy can be viewed as an 'action' describing the motion of a particle; the contours of equilibrium geometries are identified with particle trajectories. A novel Hamiltonian formulation of the problem is presented which exhibits the following two features: (i) the second derivatives appearing in the action through the mean curvature are accommodated in a natural phase space and (ii) the intrinsic freedom associated with the choice of evolution parameter along the contour is preserved. As a result, the phase space involves momenta conjugate not only to the particle position but also to its velocity, and there are constraints on the phase space variables. This formulation provides the groundwork for a field theoretical generalization to arbitrary configurations, with the particle replaced by a loop in space.

  20. Cervical Chondrocutaneous Branchial Remnants.

    Science.gov (United States)

    Klockars, Tuomas; Kajosaari, Lauri

    2017-03-01

      Cervical chondrocutaneous branchial remnants are rare malformations usually found in the lower neck. As high as 76% of patients have been reported to have associated anomalies. We review the literature and report a case series of seven patients with cervical cartilaginous remnants.   A retrospective case series of seven patients identified from the electronic hospital records.   Seven patients with cervical chondrocutaneous branchial remnants were identified (six boys and one girl). Only one of the patients had associated anomalies.   A review of the literature revealed no evidence for sinuses or cysts related to cervical chondrocutaneous branchial remnants. Operative treatment can be postponed to a suitable and safe age. There is marked variation in the reported prevalence of associated anomalies, ranging from 11% to 76%.

  1. Applications of Amniotic Membrane and Fluid in Stem Cell Biology and Regenerative Medicine

    Directory of Open Access Journals (Sweden)

    Kerry Rennie

    2012-01-01

    Full Text Available The amniotic membrane (AM and amniotic fluid (AF have a long history of use in surgical and prenatal diagnostic applications, respectively. In addition, the discovery of cell populations in AM and AF which are widely accessible, nontumorigenic and capable of differentiating into a variety of cell types has stimulated a flurry of research aimed at characterizing the cells and evaluating their potential utility in regenerative medicine. While a major focus of research has been the use of amniotic membrane and fluid in tissue engineering and cell replacement, AM- and AF-derived cells may also have capabilities in protecting and stimulating the repair of injured tissues via paracrine actions, and acting as vectors for biodelivery of exogenous factors to treat injury and diseases. Much progress has been made since the discovery of AM and AF cells with stem cell characteristics nearly a decade ago, but there remain a number of problematic issues stemming from the inherent heterogeneity of these cells as well as inconsistencies in isolation and culturing methods which must be addressed to advance the field towards the development of cell-based therapies. Here, we provide an overview of the recent progress and future perspectives in the use of AM- and AF-derived cells for therapeutic applications.

  2. RED WINE EXTRACT OBTAINED BY MEMBRANE-BASED SUPERCRITICAL FLUID EXTRACTION: PRELIMINARY CHARACTERIZATION OF CHEMICAL PROPERTIES.

    Directory of Open Access Journals (Sweden)

    W. Silva

    Full Text Available ABSTRACT This study aims to obtain an extract from red wine by using membrane-based supercritical fluid extraction. This technique involves the use of porous membranes as contactors during the dense gas extraction process from liquid matrices. In this work, a Cabernet Sauvignon wine extract was obtained from supercritical fluid extraction using pressurized carbon dioxide as solvent and a hollow fiber contactor as extraction setup. The process was continuously conducted at pressures between 12 and 18 MPa and temperatures ranged from 30 to 50ºC. Meanwhile, flow rates of feed wine and supercritical CO2 varied from 0.1 to 0.5 mL min-1 and from 60 to 80 mL min-1 (NCPT, respectively. From extraction assays, the highest extraction percentage value obtained from the total amount of phenolic compounds was 14% in only one extraction step at 18MPa and 35ºC. A summarized chemical characterization of the obtained extract is reported in this work; one of the main compounds in this extract could be a low molecular weight organic acid with aromatic structure and methyl and carboxyl groups. Finally, this preliminary characterization of this extract shows a remarkable ORAC value equal to 101737 ± 5324 µmol Trolox equivalents (TE per 100 g of extract.

  3. Comparison of Four Types of Membrane Bioreactor Systems in Terms of Shear Stress over the Membrane Surface using Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Bentzen, Thomas Ruby

    2013-01-01

    Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment to solve the perennial problem of effective solids–liquid separation. A common problem with MBR systems is clogging of the modules and fouling of the membrane, resulting in frequent cleaning and replacement...... and requires knowledge of the membrane fouling, hydrodynamics and biokinetics. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the two-phase flow in an MBR. Four cases of different MBR configurations are presented in this work, using CFD as a tool to develop...

  4. Near field fluid coupling between internal motion of the organ of Corti and the basilar membrane

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Stephen J.; Ni, Guangjian [Institute of Sound and Vibration Research, University of Southampton, Southampton (United Kingdom)

    2015-12-31

    The pressure distribution in each of the fluid chambers of the cochlea can be decomposed into a 1D, or plane wave, component and a near field component, which decays rapidly away from the excitation point. The transverse motion of the basilar membrane, BM, for example, generates both a 1D pressure field, which couples into the slow wave, and a local near field pressure, proportional to the BM acceleration, that generates an added mass on the BM due to the fluid motion. When the organ of Corti, OC, undergoes internal motion, due for example to outer hair cell activity, this motion will not itself generate any 1D pressure if the OC is incompressible and the BM is constrained not to move volumetrically, and so will not directly couple into the slow wave. This motion will, however, generate a near field pressure, proportional to the OC acceleration, which will act on the OC and thus increases its effective mass. The near field pressure due to this OC motion will also act on the BM, generating a force on the BM proportional to the acceleration of the OC, and thus create a “coupling mass” effect. By reciprocity, this coupling mass is the same as that acting on the OC due to the motion of the BM. This near field fluid coupling is initially observed in a finite element model of a slice of the cochlea. These simulations suggest a simple analytical formulation for the fluid coupling, using higher order beam modes across the width of the cochlear partition. It is well known that the added mass due to the near field pressure dominates the overall mass of the BM, and thus significantly affects the micromechanical dynamics. This work not only quantifies the added mass of the OC due its own motion in the fluid, and shows that this is important, but also demonstrates that the coupling mass effect between the BM and OC significantly affects the dynamics of simple micromechanical models.

  5. Potential antitumor therapeutic strategies of human amniotic membrane and amniotic fluid-derived stem cells.

    Science.gov (United States)

    Kang, N-H; Hwang, K-A; Kim, S U; Kim, Y-B; Hyun, S-H; Jeung, E-B; Choi, K-C

    2012-08-01

    As stem cells are capable of self-renewal and can generate differentiated progenies for organ development, they are considered as potential source for regenerative medicine and tissue replacement after injury or disease. Along with this capacity, stem cells have the therapeutic potential for treating human diseases including cancers. According to the origins, stem cells are broadly classified into two types: embryonic stem cells (ESCs) and adult stem cells. In terms of differentiation potential, ESCs are pluripotent and adult stem cells are multipotent. Amnion, which is a membranous sac that contains the fetus and amniotic fluid and functions in protecting the developing embryo during gestation, is another stem cell source. Amnion-derived stem cells are classified as human amniotic membrane-derived epithelial stem cells, human amniotic membrane-derived mesenchymal stem cells and human amniotic fluid-derived stem cells. They are in an intermediate stage between pluripotent ESCs and lineage-restricted adult stem cells, non-tumorigenic, and contribute to low immunogenicity and anti-inflammation. Furthermore, they are easily available and do not cause any controversial issues in their recovery and applications. Not only are amnion-derived stem cells applicable in regenerative medicine, they have anticancer capacity. In non-engineered stem cells transplantation strategies, amnion-derived stem cells effectively target the tumor and suppressed the tumor growth by expressing cytotoxic cytokines. Additionally, they also have a potential as novel delivery vehicles transferring therapeutic genes to the cancer formation sites in gene-directed enzyme/prodrug combination therapy. Owing to their own advantageous properties, amnion-derived stem cells are emerging as a new candidate in anticancer therapy.

  6. Amnioinfusion in term labor with low amniotic fluid due to rupture of membranes: a new indication.

    Science.gov (United States)

    Miño, M; Puertas, A; Miranda, J A; Herruzo, A J

    1999-01-01

    The null hypothesis was that the use of intrapartum amnioinfusion to induce term labor because of premature rupture of membranes when labor was complicated by low amniotic fluid volume due to vaginal loss would not improve fetal heart rate patterns, decrease the incidence of operative delivery, or improve neonatal acid-base status. 200 term pregnancies with low amniotic fluid due to vaginal loss were randomly chosen to receive intrapartum amnioinfusion or standard obstetric care without amnioinfusion. Fetal heart rate pattern, method of delivery and neonatal acid-base status were compared with Student's t test, chi-squared analysis, Mann-Whitney U- or Fisher's exact test. When amnioinfusion was used, the fetuses had lower rates of variable (74 vs. 91%, Pamnioinfusion, and babies in this group had lower rates of neonatal acidemia of arterial (22 vs. 36%, PAmnioinfusion improved fetal heart rate pattern, lowered the incidence of operative delivery, and improved neonatal acid-base status in term labor complicated by low amniotic fluid due to vaginal loss.

  7. Annexin A2 in amniotic fluid: correlation with histological chorioamnionitis, preterm premature rupture of membranes, and subsequent preterm delivery.

    Science.gov (United States)

    Namba, Fumihiko; Ina, Shihomi; Kitajima, Hiroyuki; Yoshio, Hiroyuki; Mimura, Kazuya; Saito, Shigeru; Yanagihara, Itaru

    2012-01-01

    The aim of this study was to determine whether amniotic fluid levels of annexin A2, a phospholipid-binding protein that is abundant in amnion and regulates fibrin homeostasis, are associated with histological chorioamnionitis, preterm premature rupture of the membranes, and subsequent preterm delivery. Amniotic fluid was obtained from 55 pregnant women with preterm labor and/or preterm premature rupture of the membranes before 32weeks of gestation, and amniotic fluid levels of annexin A2 were measured with a sandwich enzyme-linked immunosorbent assay. Amniotic fluid levels of annexin A2 in patients with histological chorioamnionitis was higher than that in the remainder (P=0.053), whereas amniotic fluid levels of annexin A2 in patients with preterm premature rupture of the membranes was significantly higher than that in the remainder (P=0.002). Amniotic levels of annexin A2 was a fair test (area under receiver-operator characteristic curve=0.679), and amniotic fluid levels of annexin A2>878.2ng/mL had a sensitivity of 68.8%, a specificity of 65.2%, a positive predictive value of 73.3%, and a negative predictive value of 60.0% for predicting delivery within 2weeks after amniotic fluid sampling. Furthermore, the combined use of amniotic fluid cut-off levels of 878.2ng/mL for annexin A2 and 13.3ng/mL for interleukin-8 improved the specificity (91.3%) and the positive predictive value (89.5%). We identified amniotic fluid levels of annexin A2, especially in combination with amniotic fluid levels of interleukin-8, as a novel predictive marker for preterm delivery. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.

  8. The diagnostic value of the lactate level in the vaginal fluid for determining the premature rupture of membranes

    International Nuclear Information System (INIS)

    Ahmadi, M.; Rafaei, F.; Nazari, N.

    2013-01-01

    Objectives:To determine the diagnostic value of the lactate concentration in vaginal secretions in determining the premature rupture of membranes. Subjects and Methods:One hundred 100 pregnant women with single pregnancy of gestational age 20--41 weeks were divided to two groups of 50 each. One group comprised of women with premature rupture of membranes, and the other (control group) of women with intact membranes. To verify the premature rupture of membranes in both groups, the speculum, fern, and nitrazine tests were done. Lactate Pro manual instrument was used to measure the lactate levels in vaginal fluid via enzymatic staining which was displayed on the instrument's liquid crystal display after 60 seconds. Descriptive analytic statistics and SPSS 17 software were used to analyze the data. Results The lactate concentration of 4.6 mM in the vaginal fluid was diagnostic for premature rupture of membranes. It had a sensitivity of 96%, specificity of 98.8%, accuracy of 97%, positive predictive value of 97.9%, and negative predictive value of 96%. Conclusions:Testing lactate levels in the vaginal fluid is an easy, rapid and reliable method for the diagnosis of premature rupture of membranes in pregnancy. (author)

  9. Purification and characterization of lutropin receptor from membranes of pig follicular fluid

    Energy Technology Data Exchange (ETDEWEB)

    Yarney, T.A.; Sairam, M.R.; Bhargavi, G.N.; Mohapatra, S.K. (Clinical Research Institute of Montreal, Quebec (Canada))

    1990-04-10

    Membranes derived from free floating granulosa cells in porcine ovarian follicular fluid were used as a starting material for structural characterization of both LH/hCG and FSH receptors. The receptors were highly hormone-specific and showed single classes of high-affinity binding sites. Their molecular weights as determined by affinity cross-linking with their respective {sup 125}I-ligands were similarly 70,000. The membrane-localized receptors could be solubilized with reduced Triton X-100 in the presence of 20% glycerol with good retention of hormone binding activity. The purified receptor exhibited a high specificity for hCG and hLH but not for hFSH bTSH. The purified receptor was iodinated and visualized to be composed of a major protein of M{sub r} 70,000 and other minor proteins of molecular weights ranging from 14,000 to 40,000. Except for the M{sub r} 14,000 protein, all other protein species bound to the concanavalin A-Sepharose column. The data suggest that the ovarian LH/hCG and FSH receptors are structurally similar and consist of a single polypeptide chain, as recently documented for the LH/hCG receptor.

  10. New generation of membrane efficient water-based drilling fluids: pragmatic and cost-effective solutions to borehole stability problems

    Energy Technology Data Exchange (ETDEWEB)

    Tare, U.A. [Haliburton, Calgary, AB (Canada); Mody, F.K. [Shell International E and P Inc., Calgary, AB (Canada); Tan, C.P. [CSIRO Petroleum, Kensington, WA (Australia)

    2002-06-01

    Drilling and completion operations in shales often suffer as a result of wellbore instability. Mechanical failure of the rock around a wellbore is the primary cause of shale instability. This process can be exacerbated by physico-chemical interactions between drilling fluids and shales. Water-based drilling fluids are used more and more due to environmental awareness that becomes more prevalent. Wellbore instability problems can however result from an improper application of water-based drilling fluids in those cases where drilling occurs in sensitive clay-rich formations. To meet the requirements of the petroleum industry, considerable collaborative efforts were expanded in the development of innovative environmentally acceptable water-based drilling fluids. In this paper, the authors describe the process that leads to the development of these drilling fluids. It is possible to achieve shale stability through an osmotic outflow of pore fluid and prevention/minimization of mud pressure penetration, as laboratory experiments on shale samples under realistic downhole conditions exposed to these drilling fluids prove. High membrane efficiencies, in excess of 80 per cent, were generated by this new generation of membrane efficient water-based drilling fluids. Drilling objectives resulting from an improved application of water-based drilling fluids are made possible by a fundamental understanding of the main drilling fluid-shale interaction mechanisms for shale stability and the application of experimental data to field conditions. The authors indicate that the achievement of trouble-free drilling of shales and notable reductions in non-productive time is accomplished by following the practical guidelines included in this paper for maintaining shale stability with the new generation of water-based drilling fluids. 8 refs., 2 tabs., 4 figs.

  11. The anti-apoptotic effect of fluid mechanics preconditioning by cells membrane and mitochondria in rats brain microvascular endothelial cells.

    Science.gov (United States)

    Tian, Shan; Zhu, Fengping; Hu, Ruiping; Tian, Song; Chen, Xingxing; Lou, Dan; Cao, Bing; Chen, Qiulei; Li, Bai; Li, Fang; Bai, Yulong; Wu, Yi; Zhu, Yulian

    2018-01-01

    Exercise preconditioning is a simple and effective way to prevent ischemia. This paper further provided the mechanism in hemodynamic aspects at the cellular level. To study the anti-apoptotic effects of fluid mechanics preconditioning, Cultured rats brain microvascular endothelial cells were given fluid intervention in a parallel plate flow chamber before oxygen glucose deprivation. It showed that fluid mechanics preconditioning could inhibit the apoptosis of endothelial cells, and this process might be mediated by the shear stress activation of Tie-2 on cells membrane surface and Bcl-2 on the mitochondria surface. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evolution of Supernova Remnants

    Science.gov (United States)

    Arbutina, B.

    2017-12-01

    This book, both a monograph and a graduate textbook, is based on my original research and partly on the materials prepared earlier for the 2007 and 2008 IARS Astrophysics Summer School in Istanbul, AstroMundus course 'Supernovae and Their Remnants' that was held for the first time in 2011 at the Department of Astronomy, Faculty of Mathematics, University of Belgrade, and a graduate course 'Evolution of Supernova Remnants' that I teach at the aforementioned university. The first part Supernovae (introduction, thermonuclear supernovae, core-collapse supernovae) provides introductory information and explains the classification and physics of supernova explosions, while the second part Supernova remnants (introduction, shock waves, cosmic rays and particle acceleration, magnetic fields, synchrotron radiation, hydrodynamic and radio evolution of supernova remnants), which is the field I work in, is more detailed in scope i.e. technical/mathematical. Special attention is paid to details of mathematical derivations that often cannot be found in original works or available literature. Therefore, I believe it can be useful to both, graduate students and researchers interested in the field.

  13. Ureaplasma species and Mycoplasma hominis in cervical fluid of pregnancies complicated by preterm prelabor rupture of membranes.

    Science.gov (United States)

    Musilova, Ivana; Pliskova, Lenka; Kutova, Radka; Hornychova, Helena; Jacobsson, Bo; Kacerovsky, Marian

    2016-01-01

    To evaluate Ureaplasma species and Mycoplasma hominis DNA in the cervical fluid and their association with microbial invasion of the amniotic cavity (MIAC) and/or histological chorioamnionitis (HCA) in pregnancies complicated by preterm prelabor rupture of membranes (PPROM). A prospective study of 68 women with singleton pregnancies complicated by PPROM between 24(0/7) and 36(6/7) weeks was conducted. Cervical fluid and amniotic fluid were collected from all women at the time of admission. The Ureaplasma species and Mycoplasma hominis DNA in the cervical fluid were identified using specific real-time PCR. Ureaplasma species and Mycoplasma hominis DNA were identified in 59% (40/69) of the cervical fluid samples. Women with the presence of Ureaplasma species DNA with and without Mycoplasma hominis DNA in the cervical fluid had a higher rate of MIAC alone [35% (14/40) versus 11% (3/28); p = 0.02] and a higher rate of the presence of both MIAC and HCA [30% (12/40) versus 4% (1/28); p = 0.01] than women without Ureaplasma species and Mycoplasma hominis DNA in the cervical fluid. The presence of Ureaplasma species DNA with and without Mycoplasma hominis DNA in the cervical fluid is associated with a higher risk of MIAC or MIAC and HCA together in pregnancies complicated by PPROM.

  14. Use of Extracorporeal Membrane Oxygenation in a Fulminant Course of Amniotic Fluid Embolism Syndrome Immediately after Cesarean Delivery

    Directory of Open Access Journals (Sweden)

    Jae Ha Lee

    2016-08-01

    Full Text Available Amniotic fluid embolism is rare but is one of the most catastrophic complications in the peripartum period. This syndrome is caused by a maternal anaphylactic reaction to the introduction of fetal material into the pulmonary circulation. When amniotic fluid embolism is suspected, the immediate application of extracorporeal mechanical circulatory support such as veno-arterial extracorporeal membrane oxygenation (ECMO or cardiopulmonary bypass should be considered. Without the application of extracorporeal mechanical circulatory support, medical supportive care might not be sufficient to maintain cardiopulmonary stabilization in severe cases of amniotic fluid embolism. In this report, we present the case of a 36-year-old pregnant woman who developed an amniotic fluid embolism immediately after a cesarean section. Her catastrophic event started with the sudden onset of severe hypoxia, followed by circulatory collapse within 8 minutes. The veno-arterial mode of extracorporeal membrane oxygenation was initiated immediately. She was successfully resuscitated but with impaired cognitive function. Thus, urgent ECMO should be considered when amniotic fluid embolism syndrome is suspected in patients presenting acute cardiopulmonary collapse.

  15. Antioxidant Vitamin Status in the Serum and Amniotic Fluid of Women with Premature Rupture of the Fetal Membranes.

    Science.gov (United States)

    Barrett, Bridget M.

    The purpose of this study was to examine the status of antioxidant vitamins in women with premature rupture of the fetal membranes. Specimens of blood and amniotic fluid were obtained from 80 pregnant subjects included both smokers and non-smokers during the third trimester. The concentrations of ascorbic acid (ASA), beta -carotene, retinol and alpha -tocopherol in serum and amniotic fluid were determined. The experimental group consisted of those subjects with PROM while the control subjects were those with normal pregnancy. No statistical differences were found between the PROM and control groups in retinol and vitamin E concentrations in amniotic fluid and serum. Serum ASA concentrations of PROM subjects were not different from controls, but the PROM subjects had significantly lower amniotic fluid ASA concentrations. However, in a study with fewer subjects a lower serum ASA concentration in the PROM subjects was observed. The ratio of amniotic fluid ASA concentration to ASA serum concentration was significantly lower in PROM patients than in controls in both studies. This suggests that low levels of ASA in the amniotic fluid, but not in serum is better associated with PROM. A low amniotic fluid concentration of ASA may reflect an inefficient transfer and/or increased fetal utilization. Alterations in ASA concentration in the amniotic fluid may affect the integrity of the chorioamnion leading to PROM. beta -Carotene was not found in the amniotic fluid. Serum beta-carotene levels were significantly lower in the PROM group compared to the control group. Low concentrations of beta-carotene in maternal serum in smokers not only associated with poor maternal outcome (PROM) but also compromised the fetal outcome (decreased birth weight). Maintenance of adequate serum beta-carotene concentration and amniotic fluid ASA in smokers may result in better maternal and fetal outcome. This study demonstrated that nutrition is an important factor in the prevention of PROM.

  16. Survey of Pregnancy Outcome in Preterm Premature Rupture of Membranes with Amniotic Fluid Index <5 and ≥5

    Directory of Open Access Journals (Sweden)

    Fatemeh Tavassoli

    2010-04-01

    Full Text Available Objectives: Preterm premature rupture of membranes (PPROM is among the most important causes of perinatal morbidity and mortality. The aim of this study is to survey the pregnancy outcomes in preterm premature rupture of membranes with an amniotic fluid index of 5.Methods: This prospective cohort study was performed on 137 pregnant women complicated by preterm premature rupture of membranes (PPROM with a gestational age of 28-34 weeks during October 2006 to October 2008. The patients were divided in two groups according to their amniotic fluid index; AFI<5 (77cases, AFI≥5 (60cases. The Chi-squared test for qualitative variables and T-student test for quantitative variables were used to analyze the results.Results: The results showed that there was no significant difference in terms of the number of pregnancies, gestational age at rupture of membranes and birthweight between the two groups. However, the results demonstrated that the patients with AFI<5 exhibited a significantly shorter latency period (p=0.049, a higher rate of cesarean due to fetal distress (p=0.008, a lower neonatal Apgar score in the first minute (p=0.0127 and a higher rate of neonatal death during the first week (p=0.045.Conclusion: Overall, PPROM with oligohydroamnios is associated with shorter latency, higher rate of C/S, higher rate of early neonatal death and lower neonatal Apgar.

  17. Use of urea and creatinine levels in vaginal fluid for the diagnosis of preterm premature rupture of membranes and delivery interval after membrane rupture.

    Science.gov (United States)

    Gezer, Cenk; Ekin, Atalay; Golbasi, Ceren; Kocahakimoglu, Ceysu; Bozkurt, Umit; Dogan, Askin; Solmaz, Ulaş; Golbasi, Hakan; Taner, Cuneyt Eftal

    2017-04-01

    To determine whether urea and creatinine measurements in vaginal fluid could be used to diagnose preterm premature rupture of membranes (PPROM) and predict delivery interval after PPROM. A prospective study conducted with 100 pregnant women with PPROM and 100 healthy pregnant women between 24 + 0 and 36 + 6 gestational weeks. All patients underwent sampling for urea and creatinine concentrations in vaginal fluid at the time of admission. Receiver operator curve analysis was used to determine the cutoff values for the presence of PPROM and delivery within 48 h after PPROM. In multivariate logistic regression analysis, vaginal fluid urea and creatinine levels were found to be significant predictors of PPROM (p 6.7 mg/dl for urea and >0.12 mg/dl for creatinine. The optimal cutoff values for the detection of delivery within 48 h were >19.4 mg/dl for urea and >0.23 mg/dl for creatinine. Measurement of urea and creatinine levels in vaginal fluid is a rapid and reliable test for diagnosing and also for predicting delivery interval after PPROM.

  18. Fluid migration through geo-membrane seams and through the interface between geo-membrane and geo-synthetic clay liner

    International Nuclear Information System (INIS)

    Barroso, M.

    2005-03-01

    Composite liners are used to limit the contamination migration from landfills. Their successful performance is closely related with the geo-membrane as it provides the primary barrier to diffusive and advective transport of contaminants. Critical issues on the performance of the geo-membranes are the seams between geo-membrane panels and the inevitable defects resulting, for instance, from inadequate installation activities. In landfills, where high density polyethylene geo-membranes are usually used, seams are typically made by the thermal-hot dual wedge method. A literature review on quality control of the seams showed that, in situ, fluid-tightness of seams is evaluated in qualitative terms (pass/failure criteria), despite their importance to ensure appropriate performance of the geo-membranes as barriers. In addition, a synthesis of studies on geo-membrane defects indicated that defects varying in density from 0.7 to 15.3 per hectare can be found in landfills. Defects represent preferential flow paths for leachate. Various authors have developed analytical solutions and empirical equations for predicting the flow rate through composite liners due to defects in the geo-membrane. The validity of these methods for composite liners comprising a geo-membrane over a geo-synthetic clay liner (GCL) over a compacted clay liner (CCL) has never been studied from an experimental point of view. To address the problem of fluid migration through the geo-membrane seams, an attempt is made to provide a test method, herein termed as 'gas permeation pouch test', for assessing the quality of the thermal-hot dual wedge seams. This test consists of pressurizing the air channel formed by the double seam with a gas to a specific pressure and, then, measuring the decrease in pressure over time. From the pressure decrease, both the gas permeation coefficients, in steady state conditions, and the time constant, in unsteady state conditions, can be estimated. Experiments were carried out

  19. Cryo-transmission electron microscopy of a superstructure of fluid dioleoylphosphatidylcholine (DOPC) membranes

    DEFF Research Database (Denmark)

    Klösgen, B; Helfrich, W

    1997-01-01

    a porous technical membrane. Sampling and cryofixation took place at various times within 3 weeks after the preparation. From the micrographs we infer that the small fraction of vesicles enclosing one another develop passages (connections) between the bilayers. In contrast, the superstructure is basically...... a feature of disconnected membranes. Among its modifications are isolated membrane bends or folds and a grainy membrane texture with a minimal grain spacing of 4-6 nm. In the extruded dispersions the passages and the superstructure seem to be formed mostly within the first day. The fraction of smooth...

  20. PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

    2012-05-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

  1. Comparative Study of Pregnancy Outcome in Premature Rupture of Membranes With Amniotic Fluid Indices of less and more than 5

    Directory of Open Access Journals (Sweden)

    F Tavassoli

    2010-03-01

    Full Text Available Introduction: Preterm premature rupture of the membranes (PPROM is one of the most important causes of perinatal morbidity and mortality. The aim of this study was to evaluate pregnancy outcome in preterm premature rupture of the membranes with amniotic fluid index less than 5 and more than 5. Methods: This prospective study was performed on 137 pregnant women with gestational age of 28-34 weeks with PPROM from Oct 2006 to Oct 2008. The patients were divided in two groups according to amniotic fluid index: AFI<5 (77 cases, AFI≥5 (60 cases. Chi-square test was used for qualitative variables, while T-student test was used for quantitative test. Results: Both groups were similar with respect to number of pregnancies, gestational age at rupture of the membranes and birth weight. In the group with AFI<5, applied latency was significantly shorter (PV=0.049, rate of cesarean section was higher due to fetal distress (PV=0.008, neonatal Apgar score in first minute was lower during the first week (PV=0.0127 and the rate of neonatal death was higher (PV=0.045 during the first week. Conclusion: An AFI<5 cm after PPROM is associated with earlier delivery, higher rate of cesarean due to fetal distress, higher rate of neonatal death, and lower neonatal Apgar score in first minute during the first week

  2. Mass transfer, fluid flow and membrane properties in flat and corrugated plate hyperfiltration modules

    NARCIS (Netherlands)

    Racz, I.G.; Groot Wassink, J.; Klaassen, R.

    1986-01-01

    Concentration polarisation, decreasing the efficiency in membrane separation processes, can be reduced by increasing mass transfer between membrane surface and bulk of the feed stream. Analogous to techniques used in plate heat exchangers efforts have been made to enhance mass transfer in a plate

  3. Theoretical studies on membrane-based gas separation using computational fluid dynamics (CFD) of mass transfer

    International Nuclear Information System (INIS)

    Sohrabi, M.R.; Marjani, A.; Davallo, M.; Moradi, S.; Shirazian, S.

    2011-01-01

    A 2D mass transfer model was developed to study carbon dioxide removal by absorption in membrane contactors. The model predicts the steady state absorbent and carbon dioxide concentrations in the membrane by solving the conservation equations. The continuity equations for three sub domains of the membrane contactor involving the tube; membrane and shell were obtained and solved by finite element method (FEM). The model was based on 'non-wetted mode' in which the gas phase filled the membrane pores. Laminar parabolic velocity profile was used for the liquid flow in the tube side; whereas, the gas flow in the shell side was characterized by Happel's free surface model. Axial and radial diffusion transport inside the shell, through the membrane, and within the tube side of the contactor was considered in the mass transfer model. The predictions of percent CO/sub 2/ removal obtained by modeling were compared with the experimental values obtained from literature. They were the experimental results for CO/sub 2/ removal from CO/sub 2//N/sub 2/ gas mixture with amines aqueous solutions as the liquid solvent using polypropylene membrane contactor. The modeling predictions were in good agreement with the experimental values for different values of gas and liquid flow rates. (author)

  4. Prophylactic transabdominal amnioinfusion in oligohydramnios for preterm premature rupture of membranes: increase of amniotic fluid index during latency period.

    Science.gov (United States)

    Garzetti, G G; Ciavattini, A; De Cristofaro, F; La Marca, N; Arduini, D

    1997-01-01

    This study was designed to: (i) evaluate the effect of amnioinfusion on the latency period in patients with oligohydramnios for preterm premature rupture of membranes, and (ii) to investigate the relationship between changes in the amniotic fluid index and fetal heart rate short-term variability by computerized Hewlett-Packard cardiotocography, longitudinally estimated before and after prophylactic amnioinfusion. All singleton pregnancies with prolonged premature rupture of membranes after 25 weeks of gestation and seen at the Institute of Obstetrics and Gynecology, University of Ancona (Italy), between January 1994 and June 1995 were included in the study. Transabdominal amnioinfusion with 150-350 ml warmed normal saline (25-50 ml/min) was performed at weekly intervals. Amniotic fluid volume was assessed ultrasonographically by means of the four-quadrant technique on a weekly basis before and after each amnioinfusion, as well as the short-term variability by a Hewlett-Packard computerized cardiotocographic system. 18 women were enrolled and underwent prophylactic transabdominal amnioinfusion at weekly intervals until delivery. Eighteen controls, who did not undergo prophylactic amnioinfusion, were recruited from our 1992-1993 series and included in the study. The median interval between premature rupture of membranes and delivery was 3.0 weeks (range 1-8 weeks), with an average delivery age of 33.0 weeks (range 27-36 weeks). The latency period was significantly longer in patients who underwent prophylactic amnioinfusion (mean +/- SD, 4.1 +/- 1.7 weeks) than in controls(1.7 +/- 1.0 weeks; p amnioinfusion. A direct relationship was observed between the amniotic fluid index and short-term variability (linear regression analysis r = 0.54, p = 0.04). The mean values of fetal movements recorded by computerized tomography during the 20 min of observation significantly increased after amnioinfusion in comparison with those before it (2.6 +/- 0.9 and 0.9 +/- 0

  5. Remnants of Lost Geology

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] In eastern Arabia Terra, remnants of a once vast layered terrain are evident as isolated buttes, mesas, and deeply-filled craters. The origin of the presumed sediments that created the layers is unknown, but those same sediments, now eroded, may be the source of the thick mantle of dust that covers much of Arabia Terra today.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 20.5, Longitude 50 East (310 West). 19 meter/pixel resolution.

  6. Electrokinetic migration across artificial liquid membranes. New concept for rapid sample preparation of biological fluids.

    Science.gov (United States)

    Pedersen-Bjergaard, Stig; Rasmussen, Knut Einar

    2006-03-24

    Basic drug substances were transported across a thin artificial organic liquid membrane by the application of 300 V d.c. From a 300 microl aqueous donor compartment (containing 10 mM HCl), the drugs migrated through a 200 microm artificial liquid membrane of 2-nitrophenyl octyl ether immobilized in the pores of a polypropylene hollow fiber, and into a 30 microl aqueous acceptor solution of 10 mM HCl inside the lumen of the hollow fiber. The transport was forced by an electrical potential difference sustained over the liquid membrane, resulting in electrokinetic migration of drug substances from the donor compartment to the acceptor solution. Within 5 min of operation at 300 V, pethidine, nortriptyline, methadone, haloperidol, and loperamide were extracted with recoveries in the range 70-79%, which corresponded to enrichments in the range 7.0-7.9. The chemical composition of the organic liquid membrane strongly affected the permeability, and may serve as an efficient tool for controlling the transport selectivity. Water samples, human plasma, and human urine were successfully processed, and in light of the present report, electrokinetic migration across thin artificial liquid membranes may be an interesting tool for future isolation within chemical analysis.

  7. Pseudomonas aeruginosa outer membrane vesicles triggered by human mucosal fluid and lysozyme can prime host tissue surfaces for bacterial adhesion

    Directory of Open Access Journals (Sweden)

    Matteo Maria Emiliano Metruccio

    2016-06-01

    Full Text Available Pseudomonas aeruginosa is a leading cause of human morbidity and mortality that often targets epithelial surfaces. Host immunocompromise, or the presence of indwelling medical devices, including contact lenses, can predispose to infection. While medical devices are known to accumulate bacterial biofilms, it is not well understood why resistant epithelial surfaces become susceptible to P. aeruginosa. Many bacteria, including P. aeruginosa, release Outer Membrane Vesicles (OMVs in response to stress that can fuse with host cells to alter their function. Here, we tested the hypothesis that mucosal fluid can trigger OMV release to compromise an epithelial barrier. This was tested using tear fluid and corneal epithelial cells in vitro and in vivo. After 1 h both human tear fluid, and the tear component lysozyme, greatly enhanced OMV release from P. aeruginosa strain PAO1 compared to PBS controls (~100 fold. TEM and SDS-PAGE showed tear fluid and lysozyme-induced OMVs were similar in size and protein composition, but differed from biofilm-harvested OMVs, the latter smaller with fewer proteins. Lysozyme-induced OMVs were cytotoxic to human corneal epithelial cells in vitro and murine corneal epithelium in vivo. OMV exposure in vivo enhanced Ly6G/C expression at the corneal surface, suggesting myeloid cell recruitment, and primed the cornea for bacterial adhesion (~4-fold, P < 0.01. Sonication disrupted OMVs retained cytotoxic activity, but did not promote adhesion, suggesting the latter required OMV-mediated events beyond cell killing. These data suggest that mucosal fluid induced P. aeruginosa OMVs could contribute to loss of epithelial barrier function during medical device-related infections.

  8. Influence of ethanol as bore fluid component on the morphological structure and performance of PES hollow fiber membrane for oil in water separation

    Energy Technology Data Exchange (ETDEWEB)

    Otitoju, Tunmise Ayode; Ahmad, Abdul Latif; Ooi, Boon Seng [Universiti Sains Malaysia, Penang (Malaysia)

    2017-10-15

    The relationships among varying bore fluid compositions containing ethanol/water were studied. The ethanol composition was varied in the ratio of 0%, 25%, 50%, 75% and 100%. The membrane dope solutions were prepared from 17.25 wt% polyethersulfone (PES), 0.75 wt% polyethylene glycol (PEG), 3 wt% silicon dioxide sol and 78.25 wt% of 1-methyl-2-pyrrolidone (NMP) via dry-jet spinning process. The membranes’ morphology as a result of varying ethanol ratio in the bore fluid composition was characterized and their effects on crude oil/water emulsion separation were evaluated. Results show that the membrane pore size and porosity decreased with increasing ethanol content in the bore fluid mixture, whereas the inner wall thickness of fibers increased. Furthermore, an increase in ethanol concentration also resulted in a slight increase in water contact angle. The use of 100/0 of ethanol/water resulted in UF membranes with the lowest performance. On the other hand, bore fluid mixture containing 25/75 ethanol/water produced membrane with the best performance for crude oil/water separation. Overall, the use of bore fluid mixture containing 25/75 ethanol/water mixture was found to be a powerful way to tune the morphological properties and performance of HF membrane.

  9. Influence of ethanol as bore fluid component on the morphological structure and performance of PES hollow fiber membrane for oil in water separation

    International Nuclear Information System (INIS)

    Otitoju, Tunmise Ayode; Ahmad, Abdul Latif; Ooi, Boon Seng

    2017-01-01

    The relationships among varying bore fluid compositions containing ethanol/water were studied. The ethanol composition was varied in the ratio of 0%, 25%, 50%, 75% and 100%. The membrane dope solutions were prepared from 17.25 wt% polyethersulfone (PES), 0.75 wt% polyethylene glycol (PEG), 3 wt% silicon dioxide sol and 78.25 wt% of 1-methyl-2-pyrrolidone (NMP) via dry-jet spinning process. The membranes’ morphology as a result of varying ethanol ratio in the bore fluid composition was characterized and their effects on crude oil/water emulsion separation were evaluated. Results show that the membrane pore size and porosity decreased with increasing ethanol content in the bore fluid mixture, whereas the inner wall thickness of fibers increased. Furthermore, an increase in ethanol concentration also resulted in a slight increase in water contact angle. The use of 100/0 of ethanol/water resulted in UF membranes with the lowest performance. On the other hand, bore fluid mixture containing 25/75 ethanol/water produced membrane with the best performance for crude oil/water separation. Overall, the use of bore fluid mixture containing 25/75 ethanol/water mixture was found to be a powerful way to tune the morphological properties and performance of HF membrane.

  10. Amoeboid swimming: a generic self-propulsion of cells in fluids by means of membrane deformations.

    Science.gov (United States)

    Farutin, Alexander; Rafaï, Salima; Dysthe, Dag Kristian; Duperray, Alain; Peyla, Philippe; Misbah, Chaouqi

    2013-11-27

    Microorganisms, such as bacteria, algae, or spermatozoa, are able to propel themselves forward thanks to flagella or cilia activity. By contrast, other organisms employ pronounced changes of the membrane shape to achieve propulsion, a prototypical example being the Eutreptiella gymnastica. Cells of the immune system as well as dictyostelium amoebas, traditionally believed to crawl on a substratum, can also swim in a similar way. We develop a model for these organisms: the swimmer is mimicked by a closed incompressible membrane with force density distribution (with zero total force and torque). It is shown that fast propulsion can be achieved with adequate shape adaptations. This swimming is found to consist of an entangled pusher-puller state. The autopropulsion distance over one cycle is a universal linear function of a simple geometrical dimensionless quantity A/V(2/3) (V and A are the cell volume and its membrane area). This study captures the peculiar motion of Eutreptiella gymnastica with simple force distribution.

  11. Validation of computational non-Newtonian fluid model for membrane bioreactor

    DEFF Research Database (Denmark)

    Sørensen, Lasse; Bentzen, Thomas Ruby; Skov, Kristian

    2015-01-01

    Membrane bioreactor (MBR) systems are often considered as the wastewater treatment method of the future due to its high effluent quality. One of the main problems with such systems is a relative large energy consumption, which has led to research in this specific area. A powerful tool for optimiz......Membrane bioreactor (MBR) systems are often considered as the wastewater treatment method of the future due to its high effluent quality. One of the main problems with such systems is a relative large energy consumption, which has led to research in this specific area. A powerful tool...

  12. Nanowire-integrated microporous silicon membrane for continuous fluid transport in micro cooling device

    International Nuclear Information System (INIS)

    So, Hongyun; Pisano, Albert P.; Cheng, Jim C.

    2013-01-01

    We report an efficient passive micro pump system combining the physical properties of nanowires and micropores. This nanowire-integrated microporous silicon membrane was created to feed coolant continuously onto the surface of the wick in a micro cooling device to ensure it remains hydrated and in case of dryout, allow for regeneration of the system. The membrane was fabricated by photoelectrochemical etching to form micropores followed by hydrothermal growth of nanowires. This study shows a promising approach to address thermal management challenges for next generation electronic devices with absence of external power

  13. In-situ assessment of biofilm formation in submerged membrane system using optical coherence tomography and computational fluid dynamics

    KAUST Repository

    Fortunato, Luca

    2016-09-09

    This paper introduces a novel approach to study the biofouling development on gravity driven submerged membrane bioreactor (SMBR). The on-line monitoring of biofilm formation on a flat sheet membrane was conducted non-destructively using optical coherence tomography (OCT), allowing the in-situ investigation of the biofilm structure for 43 d. The OCT enabled to obtain a time-lapse of biofilm development on the membrane under the continuous operation. Acquired real-time information on the biofilm structure related to the change in the flux profile confirming the successful monitoring of the dynamic evolution of the biofouling layer. Four different phases were observed linking the permeate flux with the change of biofilm morphology. In particular, a stable flux of 2.1±0.1 L/m2 h was achieved with the achievement of steady biofilm morphology after 30 d of operation. Biofilm descriptors, such as thickness, biofilm area, macro-porosity and roughness (absolute and relative), were calculated for each OCT acquired scans. Interestingly, relative roughness was correlated with the flux decrease. Furthermore, the precise biofilm morphology obtained from the OCT scans was used in computational fluid dynamics (CFD) simulation to better understand the role of biofilm structure on the filtration mechanism. © 2016 Elsevier B.V.

  14. Amnioinfusion in labor induction of term pregnancies with premature rupture of the membranes and low amniotic fluid.

    Science.gov (United States)

    Miño, M; Puertas, A; Herruzo, A J; Miranda, J A

    1998-05-01

    To analyze the utility of prophylactic amnioinfusion in term pregnancies with PROM and a low amniotic fluid index during labor induction. Forty-two women with amnioinfusion and 42 in a control group with amniotic fluid index (AFI) below 10 cm when admitted to labor induction were studied. All patients had electronic fetal heart rate and intrauterine pressure continuous monitoring. Amnioinfusion of normal saline (37 degrees C) was realized in the study group, using a continuous perfusion pump at 600 ml/h for 1 h, after which the AFI was again recorded; if this was amnioinfusion. Both groups were similar in age, primiparity, gestational age, initial AFI, interval from rupture of membranes until delivery and length of labor. The amnioinfusion of 600 ml in 1 h significantly increased the AFI (an increase of 7.2 +/- 3.9 vs. a decrease of 1.1 +/- 1.6, P amnioinfusion group, there was a significantly lower rate of cesarean deliveries (0 vs. 6, P amnioinfusion improves neonatal metabolic state when used in labor induction of term pregnancies with PROM and a low amniotic fluid index.

  15. Computational fluid dynamics simulations of flow and concentration polarization in forward osmosis membrane systems

    DEFF Research Database (Denmark)

    Gruber, M.F.; Johnson, C.J.; Tang, C.Y.

    2011-01-01

    is inspired by previously published CFD models for pressure-driven systems and the general analytical theory for flux modeling in asymmetric membranes. Simulations reveal a non-negligible external concentration polarization on the porous support, even when accounting for high cross-flow velocity and slip...

  16. Daptomycin inhibits cell envelope synthesis by interfering with fluid membrane microdomains

    NARCIS (Netherlands)

    Müller, A.; Wenzel, M.; Strahl, H.; Grein, F.; Saaki, T.N.V.; Kohl, B.; Siersma, T.; Bandow, J.E.; Sahl, H.-G.; Schneider, T.; Hamoen, L.W.

    2016-01-01

    Daptomycin is a highly efficient last-resort antibiotic that targets the bacterial cell membrane. Despite its clinical importance, the exact mechanism by which daptomycin kills bacteria is not fully understood. Different experiments have led to different models, including (i) blockage of cell wall

  17. Hydrophobic thickness of fluid planar monooleylglycerol membran maximally thinned by inversed micellisation

    DEFF Research Database (Denmark)

    Knudsen, P. J.; Mouritsen, Ole G.

    1999-01-01

    be measured by a capacitance technique assuming the relative permittivity of the hydrophobic part of the bilayer. Introduction of an AC microvolt technique allowed manufacture of stable thick membranes by quenching the electroconstriction observed when DC electrical potentials in the millivolt range are used...

  18. Salmeterol improves fluid clearance from alveolar-capillary membrane in COPD patients: a pilot study.

    Science.gov (United States)

    Di Marco, Fabiano; Guazzi, Marco; Sferrazza Papa, Giuseppe Francesco; Vicenzi, Marco; Santus, Pierachille; Busatto, Paolo; Piffer, Federico; Blasi, Francesco; Centanni, Stefano

    2012-02-01

    The cardiovascular component associated with chronic obstructive pulmonary disease (COPD) plays a major role in disease prognosis, accounting for 25% of the deaths. Experimental and initial clinical data suggest that beta-adrenergic agonists accelerate fluid clearance from the alveolar airspace, with potentially positive effects on cardiogenic and noncardiogenic pulmonary oedema. This pilot study investigated the acute effects of the long-acting beta-2 agonist, salmeterol, on alveolar fluid clearance after rapid saline intravenous infusion by evaluating diffusive and mechanical lung properties. Ten COPD and 10 healthy subjects were treated with salmeterol or placebo 4 h before the patient's mechanical and diffusive lung properties were measured during four non consecutive days, just before and after a rapid saline infusion, or during a similar period without an infusion. In both COPD and healthy subjects, rapid saline infusion with placebo or salmeterol premedication lead to a significant decrease in diffusion capacity for carbon monoxide (DLCO) and forced expiratory volume in 1 s (FEV1). Nonetheless, salmeterol pretreatment lead to a significantly reduced gas exchange impairment caused by saline infusion (-64% of DLCO reduction compared with placebo), whereas it did not affect changes in FEV1. In the control setting with no infusion, we found no significant change in either DLCO or mechanical properties of the lung. Salmeterol appears to provide a protective effect, not related to bronchodilation, against an acute alveolar fluid clearance challenge secondary to lung fluid overload in COPD patients. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Postprandial Hyperlipidemia and Remnant Lipoproteins.

    Science.gov (United States)

    Masuda, Daisaku; Yamashita, Shizuya

    2017-02-01

    Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

  20. An articulated predictive model for fluid-free artificial basilar membrane as broadband frequency sensor

    Science.gov (United States)

    Ahmed, Riaz; Banerjee, Sourav

    2018-02-01

    In this article, an extremely versatile predictive model for a newly developed Basilar meta-Membrane (BM2) sensors is reported with variable engineering parameters that contribute to it's frequency selection capabilities. The predictive model reported herein is for advancement over existing method by incorporating versatile and nonhomogeneous (e.g. functionally graded) model parameters that could not only exploit the possibilities of creating complex combinations of broadband frequency sensors but also explain the unique unexplained physical phenomenon that prevails in BM2, e.g. tailgating waves. In recent years, few notable attempts were made to fabricate the artificial basilar membrane, mimicking the mechanics of the human cochlea within a very short range of frequencies. To explain the operation of these sensors a few models were proposed. But, we fundamentally argue the "fabrication to explanation" approach and proposed the model driven predictive design process for the design any (BM2) as broadband sensors. Inspired by the physics of basilar membrane, frequency domain predictive model is proposed where both the material and geometrical parameters can be arbitrarily varied. Broadband frequency is applicable in many fields of science, engineering and technology, such as, sensors for chemical, biological and acoustic applications. With the proposed model, which is three times faster than its FEM counterpart, it is possible to alter the attributes of the selected length of the designed sensor using complex combinations of model parameters, based on target frequency applications. Finally, the tailgating wave peaks in the artificial basilar membranes that prevails in the previously reported experimental studies are also explained using the proposed model.

  1. Soil-fluid-structure interaction applied to the Oued Taht dam (taking into account the membrane effect.

    Directory of Open Access Journals (Sweden)

    Nasreddine Krenich

    2018-01-01

    Full Text Available The objective of this work is to analyze the dynamic behavior (modal behavior of the "Oued Taht" arch dam located at MASCARA, taking into consideration the effect of soil-fluid-structure interaction. The finite element code "Ansys" was chosen for the dynamic modeling of the dam that is the subject of this study. Three hypotheses were used for soil-structure interaction modeling; model with embedded base which corresponds to the case where the phenomenon of interactions soil-structure is neglected, model with ground of foundation without mass which consists in taking into account the kinematic component of interaction soil structure and neglecting the inertial component and the model with foundation soil with mass where the two components of soil-structure interaction are taken into account. For the fluid, the model of added masses (equivalent to the westergaard approach using the SURF element available in the Ansys code library was used. A comparison between the different models of the "Oued Taht" dam was made; it has been found that the taking into account of the soil-fluid-structure interaction phenomenon modifies the period of the system and that the modeling of the dam with and without fluid gives a very important difference of the periods. The results obtained were compared with those of the "Brezina" dam, which is a gravity dam located in BAYADH. The work has shown that the periods of the "Oued Taht" dam with soil-fluid-structure interaction modeling are very out of phase with the periods without fluid modeling (taking into account only the soilstructure interaction phenomenon. which is not the case for the Brezina dam where the periods for the two models are getting closer. The periods between the two models mentioned before are close to the dam of Brézina because the latter is a dam which participates much more by its own weight than by its vault (thickness of the vault varies between 36.3 m at the base and 5m in crest which is the

  2. Vaginal Fluid hCG Levels for Detecting Premature Rupture of Membranes

    Directory of Open Access Journals (Sweden)

    T. Artimani

    2004-04-01

    Full Text Available The aim of this study was to determine whether there is any different in hCG levels of vaginal fluids from normal pregnant women, women with confirmed PROM and with suspected PROM. After irrigating the posterior vaginal fornix with 3 ml of sterile saline and procuring vaginal washing , we measured hCG levels. Samples were analyzed from 38 normal pregnant women , 31 women with confirmed PROM , 28 women with suspected PROM. The mean of vaginal fluid hCG levels of normal pregnant women were 11.2 (0.00-98.6 mIu/ml. That of women with PROM was 140.2 (0.5 , 390.1 and that of women with suspected PROM was 21.5 (0.0 , 143.9. Sensivity was 80%, specility 83% , positive predictive value 73.7% , negative predictive value 88.1% , using a cut-value 20. It was concluded that the hCG level in vaginal fluid is a marker of PROM during third trimester.

  3. Design and fabrication of PMMA-micromachined fluid lens based on electromagnetic actuation on PMMA–PDMS bonded membrane

    International Nuclear Information System (INIS)

    Lee, June Kyoo; Park, Kyung-Woo; Choi, Ju Chan; Kim, Hak-Rin; Kong, Seong Ho

    2012-01-01

    The fabrication of a poly(methyl methacrylate) (PMMA)-micromachined fluid lens with an optimally designed built-in electromagnetic actuator was demonstrated in this study. Through a finite element method, the number of winding turns and the distance between magnetic moments were estimated to design an effective and miniaturized electromagnetic actuator. The lens body composed of PMMA structures was simply and rapidly micromachined using computer numerical control micro-milling. The poly(dimethylsiloxane) (PDMS) membranes for electromagnetic actuation were bonded to the PMMA structures by using the proposed PMMA–PDMS bonding technique, which uses an SiO 2 intermediate layer. A physical repulsive force produced by the electromagnetic actuator applies a controllable fluidic pressure to a fluidic chamber that is sealed with the PDMS membrane, thus allowing dynamic focusing. The focus tunability of the fabricated lens was 67 diopters with a focus hysteresis of less than 1 mm and a response time of 2 ms. The solenoid of the built-in actuator showed negligible thermal crosstalk to the lens. (paper)

  4. Agarose gel electrophoresis of cerebrospinal fluid proteins of dogs after sample concentration using a membrane microconcentrator technique.

    Science.gov (United States)

    Gama, Fernanda Gomes Velasque; Santana, Aureo Evangelista; Filho, Eugênio de Campos; Nogueira, Cláudia Aparecida da Silva

    2007-03-01

    Cerebrospinal fluid (CSF) is produced in the cerebral ventricles through ultrafiltration of plasma and active transport mechanisms. Evaluation of proteins in CSF may provide important information about the production of immunoglobulins within the central nervous system as well as possible disturbances in the blood-brain barrier. The objective of this study was to measure the concentration and fractions of protein in CSF samples using a membrane microconcentrator technique followed by electrophoresis, and to compare the protein fractions obtained with those in serum. CSF samples from 3 healthy dogs and 3 dogs with canine distemper virus infection were concentrated using a membrane microconcentrator having a 0.5 to 30,000 d nominal molecular weight limit (Ultrafree, Millipore, Billerica, MA, USA). Protein concentration was determined before and after concentration. Agarose gel electrophoresis was done on concentrated CSF samples, serum, and serial dilutions of one of the CSF samples. Electrophoretic bands were clearly identified in densitometer tracings in CSF samples with protein concentrations as low as 1.3 g/dL. The higher CSF protein concentration in dogs with distemper was mainly the result of increased albumin concentration. The microconcentrating method used in this study enables characterization of the main protein fractions in CSF by routine electrophoresis and may be useful for interpreting the underlying cause of changes in CSF protein concentrations.

  5. The correlation between histologic placentitis and amnionitis and the amnioniotic fluid's inflammatory cytokines in case of spontaneous pre-term labor with intact membrane

    Directory of Open Access Journals (Sweden)

    Agus Abadi

    2001-12-01

    Full Text Available Pre-term labor is presumed to result from spreading of lower genital infection to upper part, subsequently to decidual and choioamniotic tissues. Host response to this injury include the expression of protein which is responsible to the inflammatory reactions. The expression of the inflammatory cytokines such as IL-1β, IL-6, IL-8 and TNF-α increase in case of infection.These cytokines may play an essential role in the pathophysiology of spontaneous pretem labor with intact membrane.An observational analytic cohort study was caried out on cases of spontaneous pre-tefln labor with intact membrane. The objectives of this study are to examine the relationship between l the histologic amnionitis and placentitis and the incidence of preterm delivery,2 the expression of amniotic fluid's IL-1β, IL-6, IL-8 and TNF-α and the incidence of preterm delivery, 3 the level of amniotic fluid's IL-1β, IL-6, IL-8 and TNF-α and the grade of histologic amnionitis and placentitis in case of pre-term labor with intact membrane. Cases of spontaneous Pre'teftn labor with intact membrane which underwent transabdominal amniocentesis at admission and managed as standard procedure for pre-term labor with intact membrane. Atl of the cases were observed until the delivery of the baby, eithir preterm or term. The membrane and the placentawere cut postnatally and then the histologic acute inflammation eyaluated based on the criteria of Salafia.The level of amniotic fluid IL-1β, IL-6, IL-8 and TNF-α were analyzed quantitatively by Elisa method. This study showed thet the degree of histologic amnionitis and placentitis, and the level of amniotic fluid's IL-1β, IL-6, IL-8 and TNF-α were significantly higher in pre-term compared to terrn deliveries (p<0.05 and lhere were a positive correlation between the grade of histoLogic inflammation and the level of amniotic fluid's cytokines (Spearmann Rank Conelation test; p<0,05 in cases of preterm labor with intact membrane. The

  6. Analysis of fluid-solid interaction in MHD natural convection in a square cavity equally partitioned by a vertical flexible membrane

    International Nuclear Information System (INIS)

    Mehryan, S.A.M.; Ghalambaz, Mohammad; Ismael, Muneer A.; Chamkha, Ali J.

    2017-01-01

    This paper investigates numerically the problem of unsteady natural convection inside a square cavity partitioned by a flexible impermeable membrane. The finite element method with the arbitrary Lagrangian-Eulerian (ALE) technique has been used to model the interaction of the fluid and the membrane. The horizontal walls of the cavity are kept adiabatic while the vertical walls are kept isothermal at different temperatures. A uniform magnetic field is applied onto the cavity with different orientations. The cavity has been provided by two eyelets to compensate volume changes due the movement of the flexible membrane. A parametric study is carried out for the pertinent parameters, which are the Rayleigh number (10"5–10"8), Hartmann number (0–200) and the orientation of the magnetic field (0–180°). The change in the Hartmann number affects the shape of the membrane and the heat transfer in the cavity. The angle of the magnetic field orientation also significantly affects the shape of the membrane and the heat transfer in the cavity. - Highlights: • Magnetohydrodynamics heat transfer in a partitioned cavity is studied. • There is a flexible membrane in the cavity. • The membrane is modeled using fluid-solid structure interaction. • A moving grid formulation based on ALE is adopted. • The effect of the magnetic field on the natural convection heat transfer is examined.

  7. Analysis of fluid-solid interaction in MHD natural convection in a square cavity equally partitioned by a vertical flexible membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mehryan, S.A.M., E-mail: a.mansuri1366@gmail.com [Department of Mechanical Engineering, Dezful Branch, Islamic Azad University, Dezful (Iran, Islamic Republic of); Ghalambaz, Mohammad, E-mail: m.ghalambaz@iaud.ac.ir [Department of Mechanical Engineering, Dezful Branch, Islamic Azad University, Dezful (Iran, Islamic Republic of); Ismael, Muneer A., E-mail: muneerismael@yahoo.com [Mechanical Engineering Department, Engineering College, University of Basrah, Basrah (Iraq); Chamkha, Ali J., E-mail: achamkha@pmu.edu.sa [Mechanical Engineering Department, Prince Mohammad Bin Fahd University, Al-Khobar 31952 (Saudi Arabia); Prince Sultan Endowment for Energy and Environment, Prince Mohammad Bin Fahd University, Al-Khobar 31952 (Saudi Arabia)

    2017-02-15

    This paper investigates numerically the problem of unsteady natural convection inside a square cavity partitioned by a flexible impermeable membrane. The finite element method with the arbitrary Lagrangian-Eulerian (ALE) technique has been used to model the interaction of the fluid and the membrane. The horizontal walls of the cavity are kept adiabatic while the vertical walls are kept isothermal at different temperatures. A uniform magnetic field is applied onto the cavity with different orientations. The cavity has been provided by two eyelets to compensate volume changes due the movement of the flexible membrane. A parametric study is carried out for the pertinent parameters, which are the Rayleigh number (10{sup 5}–10{sup 8}), Hartmann number (0–200) and the orientation of the magnetic field (0–180°). The change in the Hartmann number affects the shape of the membrane and the heat transfer in the cavity. The angle of the magnetic field orientation also significantly affects the shape of the membrane and the heat transfer in the cavity. - Highlights: • Magnetohydrodynamics heat transfer in a partitioned cavity is studied. • There is a flexible membrane in the cavity. • The membrane is modeled using fluid-solid structure interaction. • A moving grid formulation based on ALE is adopted. • The effect of the magnetic field on the natural convection heat transfer is examined.

  8. Kinetics of the lamellar gel-fluid transition in phosphatidylcholine membranes in the presence of sugars

    Energy Technology Data Exchange (ETDEWEB)

    Lenné, Thomas; Garvey, Christopher J.; Koster, Karen L.; Bryant, Gary [ANSTO; (USD); (RMIT)

    2014-09-24

    Phase diagrams are presented for dipalmitoylphosphatidylcholine (DPPC) in the presence of sugars (sucrose) over a wide range of relative humidities (RHs). The phase information presented here, determined by small angle X-ray scattering (SAXS), is shown to be consistent with previous results achieved by differential scanning calorimetry (DSC). Both techniques show a significant effect of sucrose concentration on the phase behaviour of this phospholipid bilayer. An experimental investigation into the effect of sugars on the kinetic behaviour of the gel to fluid transition is also presented showing that increasing the sugar content appears to slightly increase the rate at which the transition occurs.

  9. Kinetics of the lamellar gel-fluid transition in phosphatidylcholine membranes in the presence of sugars

    Energy Technology Data Exchange (ETDEWEB)

    Lenné, Thomas; Garvey, Christopher J; Koster, Karen L; Bryant, Gary [ANSTO; (USD); (RMIT)

    2010-08-04

    Phase diagrams are presented for dipalmitoylphosphatidylcholine (DPPC) in the presence of sugars (sucrose) over a wide range of relative humidities (RHs). The phase information presented here, determined by small angle X-ray scattering (SAXS), is shown to be consistent with previous results achieved by differential scanning calorimetry (DSC). Both techniques show a significant effect of sucrose concentration on the phase behaviour of this phospholipid bilayer. An experimental investigation into the effect of sugars on the kinetic behaviour of the gel to fluid transition is also presented showing that increasing the sugar content appears to slightly increase the rate at which the transition occurs.

  10. Modeling supernova remnants: effects of diffusive cosmic-ray acceleration on the evolution and application to observations

    NARCIS (Netherlands)

    Kosenko, D.; Blinnikov, S.; Vink, J.

    2011-01-01

    We present numerical models for supernova remnant evolution, using a new version of the hydrodynamical code SUPREMNA. We added a cosmic-ray diffusion equation to the code scheme, employing a two-fluid approximation. We investigate the dynamics of the simulated supernova remnants with different

  11. Einstein Observations of Galactic supernova remnants

    Science.gov (United States)

    Seward, Frederick D.

    1990-01-01

    This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.

  12. HI Absorption in Merger Remnants

    Science.gov (United States)

    Teng, Stacy H.; Veileux, Sylvain; Baker, Andrew J.

    2012-01-01

    It has been proposed that ultraluminous infrared galaxies (ULIRGs) pass through a luminous starburst phase, followed by a dust-enshrouded AGN phase, and finally evolve into optically bright "naked" quasars once they shed their gas/dust reservoirs through powerful wind events. We present the results of our recent 21- cm HI survey of 21 merger remnants with the Green Bank Telescope. These remnants were selected from the QUEST (Quasar/ULIRG Evolution Study) sample of ULIRGs and PG quasars; our targets are all bolometrically dominated by AGN and sample all phases of the proposed ULIRG -> IR-excess quasar -> optical quasar sequence. We explore whether there is an evolutionary connection between ULIRGs and quasars by looking for the occurrence of HI absorption tracing neutral gas outflows; our results will allow us to identify where along the sequence the majority of a merger's gas reservoir is expelled.

  13. Interface Fluid Syndrome After Laser In Situ Keratomileusis (LASIK) Because of Fuchs Endothelial Dystrophy Reversed by Descemet Membrane Endothelial Keratoplasty (DMEK).

    Science.gov (United States)

    Luceri, Salvatore; Baksoellah, Zainab; Ilyas, Abbas; Baydoun, Lamis; Melles, Gerrit R J

    2016-12-01

    To describe a case that developed "interface fluid syndrome" after previous laser in situ keratomileusis (LASIK) because of Fuchs endothelial dystrophy (FED), which was reversed by Descemet membrane endothelial keratoplasty (DMEK). A 58-year-old male patient presented with bilateral visual impairment owing to FED and visually significant cataract. Cataract surgery was carried out in both eyes followed by DMEK in his left eye. After cataract surgery, visual acuity did not improve sufficiently because corneal thickness increased and a fine cleft with interface fluid developed between the LASIK-flap and the residual stromal bed. After uneventful DMEK in his left eye, the fluid resolved within a week and visual acuity improved rapidly. This case demonstrates that "interface fluid syndrome" after LASIK caused by concomitant endothelial dysfunction may be reversed by DMEK allowing fast visual recovery.

  14. Molecular clouds near supernova remnants

    International Nuclear Information System (INIS)

    Wootten, H.A.

    1978-01-01

    The physical properties of molecular clouds near supernova remnants were investigated. Various properties of the structure and kinematics of these clouds are used to establish their physical association with well-known remmnants. An infrared survey of the most massive clouds revealed embedded objects, probably stars whose formation was induced by the supernova blast wave. In order to understand the relationship between these and other molecular clouds, a control group of clouds was also observed. Excitation models for dense regions of all the clouds are constructed to evaluate molecular abundances in these regions. Those clouds that have embedded stars have lower molecular abundances than the clouds that do not. A cloud near the W28 supernova remnant also has low abundances. Molecular abundances are used to measure an important parameter, the electron density, which is not directly observable. In some clouds extensive deuterium fractionation is observed which confirms electron density measurements in those clouds. Where large deuterium fractionation is observed, the ionization rate in the cloud interior can also be measured. The electron density and ionization rate in the cloud near W28 are higher than in most clouds. The molecular abundances and electron densities are functions of the chemical and dynamical state of evolution of the cloud. Those clouds with lowest abundances are probably the youngest clouds. As low-abundance clouds, some clouds near supernova remnants may have been recently swept from the local interstellar material. Supernova remnants provide sites for star formation in ambient clouds by compressing them, and they sweep new clouds from more diffuse local matter

  15. Women's expectations and experiences of rupture of membranes and views of the potential use of reagent pads for detecting amniotic fluid.

    Science.gov (United States)

    Spiby, Helen; Borrelli, Sara; Hughes, Anita J

    2017-12-01

    To explore first-time mothers' expectations and experiences regarding rupture of membranes at term and their views on the potential use of reagent pads that detect amniotic fluid. There is little information available on women's experiences of spontaneous rupture of membranes, or interest in using methods to confirm rupture of membranes (e.g. reagent pads). Descriptive qualitative study, using focus groups and telephone interviews with women during pregnancy and after the birth of their first baby. Thematic analysis was undertaken to analyse women's responses. Ethics committee approval was obtained. Twenty-five women participated in the study of whom 13 contributed both during pregnancy and postpartum between October 2015-March 2016. Three overarching themes were identified from the data from women's expectations and experiences: uncertainty in how, when and where membranes may rupture; information which was felt to be limited and confirmation of rupture of membranes. The potential use of reagent pads met with varied responses. Women were interested in having facts and figures regarding rupture of membranes, such as characteristics of liquor; volume and probability of membranes rupturing spontaneously at term. Use of a pad as a means of confirmation was viewed as helpful, although the potential for increasing anxiety was raised. © 2017 John Wiley & Sons Ltd.

  16. Value of amniotic fluid IL-8 and Annexin A2 in prediction of preterm delivery in preterm labor and preterm premature rupture of membranes.

    Science.gov (United States)

    Jia, Xiaohui

    2014-01-01

    To investigate the clinical significance and value in the prediction of preterm delivery of combined amniotic fluid IL-8 and Annexin A2 levels in preterm premature rupture of membranes (PPROM) and preterm labor (PTL). Sixty pregnant women at < 32 gestational weeks who developed PTL were divided into a PPROM group and a non-PPROM group. Ten normal pregnant women served as a control group. IL-8 and Annexin A2 levels were measured in amniotic fluid samples from each patient. Amniotic fluid IL-8 and Annexin-A2 levels in PTL (PPROM and non-PPROM groups) were significantly higher than those of the controls (p < 0.05). The PPROM group displayed higher amniotic fluid Annexin-A2 levels than did the non-PPROM group, with a statistically significant difference (p < 0.05). The PPROM group showed higher amniotic fluid IL-8 levels than did the non-PPROM group; however, this was statistically insignificant (p = 0.56). Combined detection of amniotic fluid IL-8 and Annexin-A2 in the prediction of preterm delivery within 2 weeks of measurement showed sensitivity of 81.25%, specificity of 88.89% and PPV of 92.86%. Amniotic fluid IL-8 and Annexin-A2 levels are associated with the occurrence of PPROM and PTL. Combined detection of IL-8 and Annexin-A2 levels in identifying preterm delivery within 2 weeks in PTL and PPROM is of possible clinical and predictive value.

  17. Clinical significance of histologic chorioamnionitis with a negative amniotic fluid culture in patients with preterm labor and premature membrane rupture.

    Directory of Open Access Journals (Sweden)

    Jeong Woo Park

    Full Text Available To evaluate the effect of histological chorioamnionitis (HCA with a negative amniotic fluid (AF culture on adverse pregnancy and neonatal outcomes and inflammatory status in the AF compartment in women with preterm labor or preterm premature rupture of membranes (PPROM.This is a retrospective cohort study of 153 women diagnosed as having a preterm labor or PPROM (20-34 weeks who delivered singleton gestations within 48 hours of amniocentesis. AF obtained through amniocentesis was cultured, and interleukin (IL-6, IL-8, and metalloproteinase-9 (MMP-9 levels were determined. The placentas were examined histologically.The prevalence of HCA with negative AF culture was 23.5% (36/153. The women with HCA but with a negative AF culture (group 2 and those with a positive AF culture (group 3 had a significantly lower mean gestational age at amniocentesis and delivery than those with a negative AF culture and without HCA (group 1. Women in group 3 had the highest levels of AF IL-6, IL-8, and MMP-9, followed by those in group 2, and those in group 1. Composite neonatal morbidity was significantly higher in groups 2 and 3 than in group 1, but this was no longer significant after adjusting for confounders caused mainly by the impact of gestational age.In the women who delivered preterm neonates, HCA with a negative AF culture was associated with increased risks of preterm birth, intense intra-amniotic inflammatory response, and prematurity-associated composite neonatal morbidity, and its risks are similar to the risk posed by positive AF culture.

  18. Transvaginal cervical length and amniotic fluid index: can it predict delivery latency following preterm premature rupture of membranes?

    Science.gov (United States)

    Mehra, Suwan; Amon, Erol; Hopkins, Sarah; Gavard, Jeffrey A; Shyken, Jaye

    2015-03-01

    We sought to determine whether transvaginal cervical length (TVCL), amniotic fluid index (AFI), or a combination of both can predict delivery latency within 7 days in women presenting with preterm premature rupture of membranes (PPROM). This was a prospective observational study of TVCL measurements in 106 singleton pregnancies with PPROM between 23-33 weeks. Delivery latency was defined as the period (in days) from the initial TVCL after PPROM to delivery of the infant, with our primary outcome being delivery within 7 days of TVCL. The independent predictability of significant characteristics for delivery within 7 days was determined using multiple logistic regression. Sensitivity, specificity, and predictive values were used to examine whether the presence of a short TVCL, AFI, or a combination of both affected the risk of delivery within 7 days. Delivery within 7 days occurred in 51/106 (48%) of pregnancies. Median duration (interquartile range) from PPROM to delivery and TVCL to delivery was 8 days (4.0-16.0) and 8 days (3.0-15.0), respectively. Using multiple regression TVCL as a continuous variable (odds ratio, 0.65; 95% confidence interval, 0.44-0.97; P 7 days for TVCL >2 cm alone was 61%. This predictive value changed when analyzed in conjunction with an AFI ≤5 cm and >5 cm at 42% and 89%, respectively. A shorter TVCL and an AFI ≤5 cm independently predict delivery within 7 days in women presenting with PPROM. The combination of an AFI >5 cm and TVCL >2 cm greatly improved the potential to remain undelivered at 7 days following cervical length assessment. These findings may be helpful for counseling and optimizing maternal and neonatal care in women with PPROM. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Remnant cholesterol and ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G

    2014-01-01

    PURPOSE OF REVIEW: To review recent advances in the field of remnant cholesterol as a contributor to the development of ischemic heart disease (IHD). RECENT FINDINGS: Epidemiologic, mechanistic, and genetic studies all support a role for elevated remnant cholesterol (=cholesterol in triglyceride......-rich lipoproteins) as a contributor to the development of atherosclerosis and IHD. Observational studies show association between elevated remnant cholesterol and IHD, and mechanistic studies show remnant cholesterol accumulation in the arterial wall like LDL-cholesterol (LDL-C) accumulation. Furthermore, large...... genetic studies show evidence of remnant cholesterol as a causal risk factor for IHD independent of HDL-cholesterol levels. Genetic studies also show that elevated remnant cholesterol is associated with low-grade inflammation, whereas elevated LDL-C is not. There are several pharmacologic ways of lowering...

  20. Neutron Stars in Supernova Remnants and Beyond

    Science.gov (United States)

    Gvaramadze, V. V.

    We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

  1. Neutron Stars in Supernova Remnants and Beyond

    OpenAIRE

    Gvaramadze, V. V.

    2002-01-01

    We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

  2. Is the fluid mosaic (and the accompanying raft hypothesis a suitable model to describe fundamental features of biological membranes? What may be missing?

    Directory of Open Access Journals (Sweden)

    Luis Alberto Bagatolli

    2013-11-01

    Full Text Available The structure, dynamics, and stability of lipid bilayers are controlled by thermodynamic forces, leading to overall tensionless membranes with a distinct lateral organization and a conspicuous lateral pressure profile. Bilayers are also subject to built-in curvature-stress instabilities that may be released locally or globally in terms of morphological changes leading to the formation of non-lamellar and curved structures. A key controller of the bilayer’s propensity to form curved structures is the average molecular shape of the different lipid molecules. Via the curvature stress, molecular shape mediates a coupling to membrane-protein function and provides a set of physical mechanisms for formation of lipid domains and laterally differentiated regions in the plane of the membrane. Unfortunately, these relevant physical features of membranes are often ignored in the most popular models for biological membranes. Results from a number of experimental and theoretical studies emphasize the significance of these fundamental physical properties and call for a refinement of the fluid mosaic model (and the accompanying raft hypothesis.

  3. Controlling the Release of Indomethacin from Glass Solutions Layered with a Rate Controlling Membrane Using Fluid-Bed Processing. Part 1: Surface and Cross-Sectional Chemical Analysis.

    Science.gov (United States)

    Dereymaker, Aswin; Scurr, David J; Steer, Elisabeth D; Roberts, Clive J; Van den Mooter, Guy

    2017-04-03

    Fluid bed coating has been shown to be a suitable manufacturing technique to formulate poorly soluble drugs in glass solutions. Layering inert carriers with a drug-polymer mixture enables these beads to be immediately filled into capsules, thus avoiding additional, potentially destabilizing, downstream processing. In this study, fluid bed coating is proposed for the production of controlled release dosage forms of glass solutions by applying a second, rate controlling membrane on top of the glass solution. Adding a second coating layer adds to the physical and chemical complexity of the drug delivery system, so a thorough understanding of the physical structure and phase behavior of the different coating layers is needed. This study aimed to investigate the surface and cross-sectional characteristics (employing scanning electron microscopy (SEM) and time of flight secondary ion mass spectrometry (ToF-SIMS)) of an indomethacin-polyvinylpyrrolidone (PVP) glass solution, top-coated with a release rate controlling membrane consisting of either ethyl cellulose or Eudragit RL. The implications of the addition of a pore former (PVP) and the coating medium (ethanol or water) were also considered. In addition, polymer miscibility and the phase analysis of the underlying glass solution were investigated. Significant differences in surface and cross-sectional topography of the different rate controlling membranes or the way they are applied (solution vs dispersion) were observed. These observations can be linked to the polymer miscibility differences. The presence of PVP was observed in all rate controlling membranes, even if it is not part of the coating solution. This could be attributed to residual powder presence in the coating chamber. The distribution of PVP among the sample surfaces depends on the concentration and the rate controlling polymer used. Differences can again be linked to polymer miscibility. Finally, it was shown that the underlying glass solution layer

  4. Dynamical study of merger remnants

    International Nuclear Information System (INIS)

    Lake, G.; Dressler, A.; ATandT Bell Labs., Murray Hill, NJ; Mount Wilson and Las Campanas Observatories, Pasadena, CA; Carnegie Institution of Washington, Washington, DC)

    1986-01-01

    The velocity dispersion of objects from the Arp and the Arp-Madore atlases that have characteristics of recently merged galaxies is measured. These data are used to test the hypothesis that the remnants become normal elliptical galaxies after the fireworks of recent star formation subside. Accurate velocity dispersions of objects dominated by Balmer lines in the blue were measured using the uncontaminated Ca triplet feature in the extreme red (8400-8700 A). No deviation from the velocity dispersion expected for elliptical galaxies of comparable luminosity, is found, e.g., these systems follow the usual L-sigma relation with no zero-point shift. For a few galaxies without Balmer contamination, stellar rotation velocities are determined. One slow, one moderate, and one fast rotator are found. 54 references

  5. Progenitor's Signatures in Type Ia Supernova Remnants

    NARCIS (Netherlands)

    Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.

    2013-01-01

    The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that

  6. Mass Spectrometric Determination of the Effect of Surface Deactivation on Membranes Used for In-Situ Sampling of Cerebrospinal Fluid (CSF

    Directory of Open Access Journals (Sweden)

    Torgny Undin

    2018-05-01

    Full Text Available In this paper, a strategy for structured monitoring of surface modifications to control protein adsorption to membrane structures is presented. The already established on-surface enzymatic digestion (oSED method combined with nano-liquid chromatography and tandem mass spectrometry (LC-MS/MS analysis was employed for the analysis of proteins in ventricular cerebrospinal fluid (vCSF from neurointensive care patients. Protein adsorption was studied by in-situ sampling in a temporally resolved manner on both immobilized native and Pluronic-deactivated membranes. Deactivation was significantly reducing the protein adsorption but it also induced novel selective properties of the surface. The proposed versatile strategy will facilitate protein-biomaterial, protein-polymer, protein-protein interaction studies in the future.

  7. [ARTHROSCOPIC STUDY OF REMNANT-PRESERVED RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT].

    Science.gov (United States)

    Lu, Daifeng; Xiao, Mochao; Zhang, Yunpeng; Yan, Shi; Dong, Feng; Lian, Yongyun

    2015-08-01

    To investigate the value of ligament remnant preservation during anterior cruciate ligament (ACL) reconstruction by observing the integrity, the tension, the synovial membrane covering, and the color of the reconstructed ligament under arthroscopy. Between January 2011 and December 2013, 122 patients who underwent ACL reconstruction and arthroscopic internal fixation removal at 1 year after reconstruction were included in this study. Of these cases, 61 cases underwent ACL reconstruction using the remnant-preserved technique (preservation group); the other 61 cases underwent ACL reconstruction using non remnant-preserved technique (non preservation group). There was no significant difference in gender, age, injury side, body mass index, type of injury, the time from injury to reconstruction, and the result of KT-2000 examination between 2 groups (P > 0.05). The reconstructed ACL were observed under arthroscopy when internal fixation was removed, and the effectiveness was evaluated according to the criteria of AO Yingfang. In preservation group, the results were excellent in 34 cases, good in 22 cases, fair in 4 cases, and poor in 1 case; and in non preservation group, the results were excellent in 29 cases, good in 20 cases, fair in 10 cases, and poor in 2 cases; and there was no significant difference between 2 groups (Z= -1.320, P=0.187). In ACL reconstruction, the remnant-preserved technique is not obviously better than non remnant-preserved technique in the integrity, tension, membrane covering, and color.

  8. Hydrodynamic evolution of neutron star merger remnants

    Science.gov (United States)

    Liu, Men-Quan; Zhang, Jie

    2017-11-01

    Based on the special relativistic hydrodynamic equations and updated cooling function, we investigate the long-term evolution of neutron stars merger (NSM) remnants by a one-dimensional hydrodynamic code. Three NSM models from one soft equation of state, SFHo, and two stiff equations of state, DD2 and TM1, are used to compare their influences on the hydrodynamic evolution of remnants. We present the luminosity, mass and radius of remnants, as well as the velocity, temperature and density of shocks. For a typical interstellar medium (ISM) density with solar metallicity, we find that the NSM remnant from the SFHo model makes much more changes to ISM in terms of velocity, density and temperature distributions, compared with the case of DD2 and TM1 models. The maximal luminosity of the NSM remnant from the SFHo model is 3.4 × 1038 erg s-1, which is several times larger than that from DD2 and TM1 models. The NSM remnant from the SFHo model can maintain high luminosity (>1038 erg s-1) for 2.29 × 104 yr. Furthermore, the density and temperature of remnants at the maximal luminosity are not sensitive to the power of the original remnant. For the ISM with the solar metallicity and nH = 1 cm- 3, the density of the first shock ∼10-23 g cm-3 and the temperature ∼3 × 105 K in the maximal luminosity phase; The temperature of the first shock decreases and there is a thin 'dense' shell with density ∼10-21 g cm-3 after the maximal luminosity. These characteristics may be helpful for future observations of NSM remnants.

  9. Density and energy of supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Canto, J [Manchester Univ. (UK). Dept. of Astronomy

    1977-12-01

    The effects of an interstellar magnetic field on the gas flow behind a strong shock front are considered. The ambient density and energy of supernova remnants are estimated from the intensity ratio of sulphur lines I(6717)/I(6731). It is found that, on average, the ambient density around galactic supernova remnants is 4 cm/sup -3/. The total energy appears to be the same for all supernova remnants (to within a factor = approximately 5). A mean value of 4 10/sup 51/ erg is found.

  10. Remnants of strong tidal interactions

    International Nuclear Information System (INIS)

    Mcglynn, T.A.

    1990-01-01

    This paper examines the properties of stellar systems that have recently undergone a strong tidal shock, i.e., a shock which removes a significant fraction of the particles in the system, and where the shocked system has a much smaller mass than the producer of the tidal field. N-body calculations of King models shocked in a variety of ways are performed, and the consequences of the shocks are investigated. The results confirm the prediction of Jaffe for shocked systems. Several models are also run where the tidal forces on the system are constant, simulating a circular orbit around a primary, and the development of tidal radii under these static conditions appears to be a mild process which does not dramatically affect material that is not stripped. The tidal radii are about twice as large as classical formulas would predict. Remnant density profiles are compared with a sample of elliptical galaxies, and the implications of the results for the development of stellar populations and galaxies are considered. 38 refs

  11. Effect of intra-membrane C60 fullerenes on the modulus of elasticity and the mechanical resistance of gel and fluid lipid bilayers

    Science.gov (United States)

    Zhou, Jihan; Liang, Dehai; Contera, Sonia

    2015-10-01

    Penetration and partition of C60 to the lipid bilayer core are both relevant to C60 toxicity, and useful to realise C60 biomedical potential. A key aspect is the effect of C60 on bilayer mechanical properties. Here, we present an experimental study on the mechanical effect of the incorporation of C60 into the hydrophobic core of fluid and gel phase zwitterionic phosphatidylcholine (PC) lipid bilayers. We demonstrate its incorporation inside the hydrophobic lipid core and the effect on the packing of the lipids and the vesicle size using a combination of infrared (IR) spectroscopy, atomic force microscopy (AFM) and laser light scattering. Using AFM we measured the Young's modulus of elasticity (E) of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) in the absence (presence) of intra-membranous C60 at 24.5 °C. E of fluid phase supported bilayers is not altered by C60, but E increases with incorporation of C60 in gel phase bilayers. The increase is higher for longer hydrocarbon chains: 1.6 times for DPPC and 2 times for DSPC. However the mechanical resistance of gel phase bilayers of curved bilayered structures decreases with the incorporation of C60. Our combined results indicate that C60 causes a decrease in gel phase lipid mobility, i.e. an increase in membrane viscosity.

  12. Process to remove turbidity-causing components from a fluid by micro-filtration - passes the fluid across an asymmetric membrane with inlet pores larger than those of nominal size, and cleans the membrane by backwashing

    DEFF Research Database (Denmark)

    1995-01-01

    turbidity-causing components from beer, wine, fruit juice, milk and blood, and from bacterial and enzyme suspensions. ADVANTAGE-The process greatly reduces the lost production time associated with earlier filtration methods, and beneficial components can pass through the membrane, thereby improving...

  13. A Model of the Vela Supernova Remnant

    Science.gov (United States)

    Gvaramadze, Vasilii

    2000-10-01

    A model of the Vela supernova remnant (SNR) based on a cavity explosion of a supernova (SN) star is proposed. It is suggested that the general structure of the remnant is determined by the interaction of the SN blast wave with a massive shell created by the SN progenitor (15-20 M_solar) star. A possible origin of the nebula of hard X-ray emission detected around the Vela pulsar is discussed.

  14. Evolution of supernova remnants. III. Thermal waves

    International Nuclear Information System (INIS)

    Chevalier, R.A.

    1975-01-01

    The effect of heat conduction on the evolution of supernova remnants is investigated. A thermal wave, or electron conduction front, can travel more rapidly than a shock wave during the first thousand years of the remnant's evolution. A self-similar solution describing this phase has been found by Barenblatt. Numerical computations verify the solution and give the evolution past the thermal wave phase. While shell formation is not impeded, the interior density and temperature profiles are smoothed by the action of conduction

  15. Supernova Remnant in 3-D

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Click on the image for the movie For the first time, a multiwavelength three-dimensional reconstruction of a supernova remnant has been created. This stunning visualization of Cassiopeia A, or Cas A, the result of an explosion approximately 330 years ago, uses data from several telescopes: X-ray data from NASA's Chandra X-ray Observatory, infrared data from NASA's Spitzer Space Telescope and optical data from the National Optical Astronomy Observatory 4-meter telescope at Kitt Peak, Ariz., and the Michigan-Dartmouth-MIT 2.4-meter telescope, also at Kitt Peak. In this visualization, the green region is mostly iron observed in X-rays. The yellow region is a combination of argon and silicon seen in X-rays, optical, and infrared including jets of silicon plus outer debris seen in the optical. The red region is cold debris seen in the infrared. Finally, the blue reveals the outer blast wave, most prominently detected in X-rays. Most of the material shown in this visualization is debris from the explosion that has been heated by a shock moving inwards. The red material interior to the yellow/orange ring has not yet encountered the inward moving shock and so has not yet been heated. These unshocked debris were known to exist because they absorb background radio light, but they were only recently discovered in infrared emission with Spitzer. The blue region is composed of gas surrounding the explosion that was heated when it was struck by the outgoing blast wave, as clearly seen in Chandra images. To create this visualization, scientists took advantage of both a previously known phenomenon the Doppler effect and a new technology that bridges astronomy and medicine. When elements created inside a supernova, such as iron, silicon and argon, are heated they emit light at certain wavelengths. Material moving towards the observer will have shorter wavelengths and material moving away will have longer wavelengths. Since the amount

  16. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium.

    Science.gov (United States)

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-05-01

    Electromembrane extraction was used for simultaneous sample cleanup and preconcentration of lithium from untreated human body fluids. The sample of a body fluid was diluted 100 times with 0.5 mM Tris solution and lithium was extracted by electromigration through a supported liquid membrane composed of 1-octanol into 100 mM acetic acid acceptor solution. Matrix compounds, such as proteins, red blood cells, and other high-molecular-weight compounds were efficiently retained on the supported liquid membrane. The liquid membrane was anchored in pores of a short segment of a polypropylene hollow fiber, which represented a low cost, single use, disposable extraction unit and was discarded after each use. Acceptor solutions were analyzed using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4) D) and baseline separation of lithium was achieved in a background electrolyte solution consisting of 18 mM L-histidine and 40 mM acetic acid at pH 4.6. Repeatability of the electromembrane extraction-CE-C(4) D method was evaluated for the determination of lithium in standard solutions and real samples and was better than 0.6 and 8.2% for migration times and peak areas, respectively. The concentration limit of detection of 9 nM was achieved. The developed method was applied to the determination of lithium in urine, blood serum, blood plasma, and whole blood at both endogenous and therapeutic concentration levels. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Modulation of amniotic fluid activin-a and inhibin-a in women with preterm premature rupture of the membranes and infection-induced preterm birth.

    Science.gov (United States)

    Rosenberg, Victor A; Buhimschi, Irina A; Dulay, Antonette T; Abdel-Razeq, Sonya S; Oliver, Emily A; Duzyj, Christina M; Lipkind, Heather; Pettker, Christian M; Buhimschi, Catalin S

    2012-02-01

    Activins and inhibins are important modulators of inflammatory processes. We explored activation of amniotic fluid (AF) activin-A and inhibin-A system in women with intra-amniotic infection and preterm premature rupture of the membranes (PPROM). We analyzed 78 AF samples: '2nd trimester-control' (n=12), '3rd trimester-control' (n=14), preterm labor with intact membranes [positive-AF-cultures (n=13), negative-AF-cultures (n=13)], and PPROM [positive-AF-cultures (n=13), negative-AF-cultures (n=13)]. Activin-A levels were evaluated ex-vivo following incubation of amniochorion and placental villous explants with Gram-negative lipopolysaccharide (LPS) or Gram-positive (Pam3Cys) bacterial mimics. Ability of recombinant activin-A and inhibin-A to modulate inflammatory reactions in fetal membranes was explored through explants' IL-8 release. Activin-A and inhibin-A were present in human AF and were gestational age-regulated. Activin-A was significantly upregulated by infection. Lower inhibin-A levels were seen in PPROM. LPS elicited release of activin-A from amniochorion, but not from villous explants. Recombinant activin-A stimulated IL-8 release from amniochorion, an effect that was not reversed by inhibin-A. Human AF activin-A and inhibin-A are involved in biological processes linked to intra-amniotic infection/inflammation-induced preterm birth. © 2011 John Wiley & Sons A/S.

  18. Non-invasively collected amniotic fluid as a source of possible biomarkers for premature rupture of membranes investigated by proteomic approach.

    Science.gov (United States)

    Consonni, Sara; Mainini, Veronica; Pizzardi, Agnese; Gianazza, Erica; Chinello, Clizia; Locatelli, Anna; Magni, Fulvio

    2014-02-01

    Preterm delivery is one of the main causes of perinatal morbidity and mortality and it accounts for 75 % of perinatal mortality and more than half of the long-term morbidity. We applied a proteomic approach based on mass spectrometry (MS) for biomarkers discovery of preterm premature rupture of membranes (pPROM) by investigating amniotic fluid (AF) invasively and non-invasively collected. Amniotic fluid was obtained from vagina of women with pPROM (group 1), PROM at term (group 2) and by genetic amniocentesis (group 3). Pre-fractionated AF proteome was analyzed through matrix assisted laser desorption ionization-time of flight (MALDI-TOF) MS. The characterization of proteins/peptides of interest was obtained by high performance liquid chromatography-electrospray tandem MS. Three peptides overexpressed in pPROM and able to discriminate the groups 1 and 2 were detected. One peptide was identified as the fragment Gly452LAVPDGPLGLPPKPro466 of the protein KIAA1522, expressed by fetal brain and liver. This peptide was overexpressed in a patient of the group 3, completely asymptomatic at the time of the amniocentesis, who later developed pPROM. Amniotic fluid invasively and non-invasively collected can be analyzed by MALDI-TOF MS to obtain proteomic profiles. Proteomic analysis identified a peptide with promising diagnostic capability for pPROM.

  19. Cholesterol rules: direct observation of the coexistence of two fluid phases in native pulmonary surfactant membranes at physiological temperatures

    DEFF Research Database (Denmark)

    Bernardino de la Serna, Jorge; Perez-Gil, Jesus; Simonsen, Adam C

    2004-01-01

    part in the surfactant structures could be organized heterogeneously in the form of inplane domains, originating from particular distributions of specific proteins and lipids. Here we report novel results concerning the lateral organization of bilayer membranes made of native pulmonary surfactant where...

  20. In-situ assessment of biofilm formation in submerged membrane system using optical coherence tomography and computational fluid dynamics

    KAUST Repository

    Fortunato, Luca; Qamar, Adnan; Wang, Yiran; Jeong, Sanghyun; Leiknes, TorOve

    2016-01-01

    coherence tomography (OCT), allowing the in-situ investigation of the biofilm structure for 43 d. The OCT enabled to obtain a time-lapse of biofilm development on the membrane under the continuous operation. Acquired real-time information on the biofilm

  1. Radioiodine Remnant Ablation: A Critical Review

    International Nuclear Information System (INIS)

    Bal, Chandra Sekhar; Padhy, Ajit Kumar

    2015-01-01

    Radioiodine remnant ablation (RRA) is considered a safe and effective method for eliminating residual thyroid tissue, as well as microscopic disease if at all present in thyroid bed following thyroidectomy. The rationale of RRA is that in the absence of thyroid tissue, serum thyroglobulin (Tg) measurement can be used as an excellent tumor marker. Other considerations are like the presence of significant remnant thyroid tissue makes detection and treatment of nodal or distant metastases difficult. Rarely, microscopic disease in the thyroid bed if not ablated, in the future, could be a source of anaplastic transformation. On the other hand, microscopic tumor emboli in distant sites could be the cause of distant metastasis too. The ablation of remnant tissue would in all probability eliminate these theoretical risks. It may be noted that all these are unproven contentious issues except postablation serum Tg estimation that could be a good tumor marker for detecting early biochemical recurrence in long-term follow-up strategy. Radioactive iodine is administered as a form of “adjuvant therapy” for remnant ablation. There have been several reports with regard to the administered dose for remnant ablation. The first report of a prospective randomized clinical trial was published from India by a prospective randomized study conducted at the All India Institute of Medical Sciences, New Delhi in the year 1996. The study reported that increasing the empirical 131 I initial dose to more than 50 mCi results in plateauing of the dose-response curve and thus, conventional high-dose remnant ablation needs critical evaluation. Recently, two important studies were published: One from French group and the other from UK on a similar line. Interestingly, all three studies conducted in three different geographical regions of the world showed exactly similar conclusion. The new era of low-dose remnant ablation has taken a firm scientific footing across the continents

  2. Premature rupture of membranes

    Science.gov (United States)

    ... gov/ency/patientinstructions/000512.htm Premature rupture of membranes To use the sharing features on this page, ... water that surrounds your baby in the womb. Membranes or layers of tissue hold in this fluid. ...

  3. Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

    NARCIS (Netherlands)

    Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.; Kaastra, J.S.

    2013-01-01

    The well-established Type Ia remnant of Tycho's supernova (SN 1572) reveals discrepant ambient medium-density estimates based on either the measured dynamics or the X-ray emission properties. This discrepancy can potentially be solved by assuming that the supernova remnant (SNR) shock initially

  4. A COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF AIR FLOW THROUGH A TELECOM BACK-UP UNIT POWERED BY AN AIR-COOLED PROTON EXCHANGE MEMBRANE FUEL CELL

    DEFF Research Database (Denmark)

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    2016-01-01

    Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and heat....... This product heat has to be effectively removed from the fuel cell, and while automotive fuel cells are usually liquid-cooled using a secondary coolant loop similar to the internal combustion engines, stationary fuel cell systems as they are used for telecom back-up applications often rely on excessive air fed...... to the fuel cell cathode to remove the heat. Thereby, the fuel cell system is much simpler and cheaper while the fuel cell performance is substantially lower compared to automotive fuel cells. This work presents a computational fluid dynamics analysis on the heat management of an air-cooled fuel cell powered...

  5. Autopsy of the Supernova Remnant Cassiopeia A

    Science.gov (United States)

    Milisavljevic, Dan; Fesen, Robert A.

    2014-01-01

    Three-dimensional kinematic reconstructions of optically emitting ejecta in the young Galactic supernova remnant Cassiopeia A (Cas A) are discussed. The reconstructions encompass the remnant's faint outlying ejecta knots, including the exceptionally high-velocity NE and SW streams of debris often referred to as `jets'. The bulk of Cas A's ejecta are arranged in several circular rings with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). We suggest that similar large-scale ejecta rings may be a common phenomenon of young core-collapse remnants and may explain lumpy emission line profile substructure sometimes observed in spectra of extragalactic core-collapse supernovae years after explosion. A likely origin for these large ejecta rings is post-explosion input of energy from plumes of radioactive 56Ni-rich ejecta that rise, expand, and compress non-radioactive material to form bubble-like structures.

  6. Cosmic Ray Acceleration in Supernova Remnants

    International Nuclear Information System (INIS)

    O'C Drury, Luke

    2005-01-01

    This paper describes some recent developments in our understanding of cosmic ray acceleration in supernova remnant shocks. It is pointed out that while good agreement now exists as to steady nonlinear modifications to the shock structure, there is also growing evidence that the mesoscopic scales may not in fact be steady and that significant instabilities associated with magnetic field amplification may be a feature of strong collisionless plasma shocks. There is strong observational evidence for such magnetic field amplification, and it appears to solve a number of long-standing issues concerned with acceleration of cosmic rays in supernova remnants

  7. X-ray haloes around supernova remnants

    International Nuclear Information System (INIS)

    Morfill, G.E.; Aschenbach, B.

    1984-01-01

    Recent observations of the Cas-A supernova remnant have shown X-ray emissions not only from the interior, but also from a fainter 'halo' extending beyond what is normally regarded as the outer boundary, or shock front. The authors suggest that this may be due to the diffusion of energetic, charged particles out of the remnant giving rise to precursor structure of the type predicted by the theory of diffusive shock acceleration. If this is the case we are seeing thermal emission from ambient gas heated by compression and wave dissipation. (author)

  8. X-ray haloes around supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Morfill, G.E.; Aschenbach, B. (Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik); Drury, L.O' C. (Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.))

    1984-09-27

    Recent observations of the Cas-A supernova remnant have shown X-ray emissions not only from the interior, but also from a fainter 'halo' extending beyond what is normally regarded as the outer boundary, or shock front. The authors suggest that this may be due to the diffusion of energetic charged particles out of the remnant giving rise to precursor structure of the type predicted by the theory of diffusive shock acceleration. If this is the case we are seeing thermal emission from ambient gas heated by compression and wave dissipation.

  9. Comparison of the membrane-filtration fluorescent antibody test, the enzyme-linked immunosorbent assay, and the polymerase chain reaction to detect Renibacterium salmoninarum in salmon ovarian fluid

    Science.gov (United States)

    Pascho, Ronald J.; Chase, Dorothy M.; McKibben, Constance L.

    1998-01-01

    Ovarian fluid samples from naturally infected chinook salmon (Oncorhynchus tshawytscha) were examined for the presence of Renibacterium salmoninarum by the membrane-filtration fluorescent antibody test (MF-FAT), an antigen capture enzyme-linked immunosorbent assay (ELISA), and a nested polymerase chain reaction (PCR). On the basis of the MF-FAT, 64% (66/103) samples contained detectable levels of R. salmoninarum cells. Among the positive fish, the R. salmoninarum concentrations ranged from 25 cells/ml to 4.3 × 109cells/ml. A soluble antigenic fraction of R. salmoninarum was detected in 39% of the fish (40/103) by the ELISA. The ELISA is considered one of the most sensitive detection methods for bacterial kidney disease in tissues, yet it did not detect R. salmoninarum antigen consistently at bacterial cell concentrations below about 1.3 × 104cells/ml according to the MF-FAT counts. When total DNA was extracted and tested in a nested PCR designed to amplify a 320-base-pair region of the gene encoding a soluble 57-kD protein of R. salmoninarum, 100% of the 100 samples tested were positive. The results provided strong evidence that R. salmoninarum may be present in ovarian fluids thought to be free of the bacterium on the basis of standard diagnostic methods.

  10. Particle acceleration and nonthermal radiation in supernova remnants

    International Nuclear Information System (INIS)

    Zirakashvili, Vladimir

    2013-01-01

    Cosmic ray acceleration and magnetic amplification in shell-type supernova remnants is shortly reviewed. The results on the modeling of broadband electromagnetic emission from supernova remnants are presented and compared with observations.

  11. GALACTIC AND EXTRAGALACTIC SUPERNOVA REMNANTS AS SITES OF PARTICLE ACCELERATION

    Directory of Open Access Journals (Sweden)

    Manami Sasaki

    2013-12-01

    Full Text Available Supernova remnants, owing to their strong shock waves, are likely sources of Galactic cosmic rays. Studies of supernova remnants in X-rays and gamma rays provide us with new insights into the acceleration of particles to high energies. This paper reviews the basic physics of supernova remnant shocks and associated particle acceleration and radiation processes. In addition, the study of supernova remnant populations in nearby galaxies and the implications for Galactic cosmic ray distribution are discussed.

  12. Plasma membrane Ca2+-ATPase 4 in murine epididymis: secretion of splice variants in the luminal fluid and a role in sperm maturation.

    Science.gov (United States)

    Patel, Ramkrishna; Al-Dossary, Amal A; Stabley, Deborah L; Barone, Carol; Galileo, Deni S; Strehler, Emanuel E; Martin-DeLeon, Patricia A

    2013-07-01

    Plasma membrane Ca(2+)-ATPase isoform 4 (PMCA4) is the primary Ca(2+) efflux pump in murine sperm, where it regulates motility. In Pmca4 null sperm, motility loss results in infertility. We have shown that murine sperm PMCA4b interacts with Ca(2+)/CaM-dependent serine kinase (CASK) in regulating Ca(2+) homeostasis and motility. However, recent work indicated that the bovine PMCA4a splice variant (missing in testis) is epididymally expressed, along with 4b, and may be transferred to sperm. Here we show, via conventional and in situ RT-PCR, that both the splice variants of Pmca4 mRNA are expressed in murine testis and throughout the epididymis. Immunofluorescence localized PMCA4a to the apical membrane of the epididymal epithelium, and Western analysis not only confirmed its presence but showed for the first time that PMCA4a and PMCA4b are secreted in the epididymal luminal fluid (ELF), from which epididymosomes containing PMCA4a were isolated. Flow cytometry indicated the presence of PMCA4a on mature caudal sperm where it was increased ~5-fold compared to caput sperm (detected by Western blotting) and ~2-fold after incubation in ELF, revealing in vitro uptake and implicating PMCA4a in epididymal sperm maturation. Coimmunoprecipitation using pan-PMCA4 antibodies, revealed that both variants associate with CASK, suggesting their presence in a complex. Because they have different kinetic properties for Ca(2+) transport and different abilities to bind to CASK, our study suggests a mechanism for combining the functional attributes of both PMCA4 variants, leading to heightened efficiency of the pump in the maintenance of Ca(2+) homeostasis, which is crucial for normal motility and male fertility.

  13. Neutron Star/supernova Remnant Associations

    Science.gov (United States)

    Gvaramadze, V. V.

    We propose a new approach for studying the neutron star/supernova remnant associations, based on the idea that the (diffuse) supernova remnants (SNRs) can be products of an off-centred supernova (SN) explosion in a preexisting bubble created by the wind of a moving massive star. A cavity SN explosion of a moving star results in a considerable offset of the neutron star (NS) birth-place from the geometrical centre of the SNR. Therefore: a) the high transverse velocities inferred for a number of NSs (e.g. PSR B 1610-50, PSR B 1757-24, SGR 0525-66) through their association with SNRs can be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR. Taking into account of these two facts allow us to enlarge the circle of possible NS/SNR associations, and could significantly affect the results of previous studies of NS/SNR associations. The possibilities of our approach are illustrated with the example of the association between PSR B 1706-44 and SNR G 343.1-2.3. We show that this association could be real if both objects are the remnants of a SN exploded within a mushroom-like cavity (created by the SN progenitor wind breaking out of the parent molecular cloud and expanding into an intercloud medium of a much less density). We also show that the SN explosion sites in some middle-aged (shell-like) SNRs could be marked by (compact) nebulae of thermal X-ray emission. The possible detection of such nebulae within middle-aged SNRs could be used for the re-estimation of implied transverse velocities of known NSs or for the search of new stellar remnants possibly associated with these SNRs.

  14. Mesenchymal Stem/Progenitor Cells Derived from Articular Cartilage, Synovial Membrane and Synovial Fluid for Cartilage Regeneration: Current Status and Future Perspectives.

    Science.gov (United States)

    Huang, Yi-Zhou; Xie, Hui-Qi; Silini, Antonietta; Parolini, Ornella; Zhang, Yi; Deng, Li; Huang, Yong-Can

    2017-10-01

    Large articular cartilage defects remain an immense challenge in the field of regenerative medicine because of their poor intrinsic repair capacity. Currently, the available medical interventions can relieve clinical symptoms to some extent, but fail to repair the cartilaginous injuries with authentic hyaline cartilage. There has been a surge of interest in developing cell-based therapies, focused particularly on the use of mesenchymal stem/progenitor cells with or without scaffolds. Mesenchymal stem/progenitor cells are promising graft cells for tissue regeneration, but the most suitable source of cells for cartilage repair remains controversial. The tissue origin of mesenchymal stem/progenitor cells notably influences the biological properties and therapeutic potential. It is well known that mesenchymal stem/progenitor cells derived from synovial joint tissues exhibit superior chondrogenic ability compared with those derived from non-joint tissues; thus, these cell populations are considered ideal sources for cartilage regeneration. In addition to the progress in research and promising preclinical results, many important research questions must be answered before widespread success in cartilage regeneration is achieved. This review outlines the biology of stem/progenitor cells derived from the articular cartilage, the synovial membrane, and the synovial fluid, including their tissue distribution, function and biological characteristics. Furthermore, preclinical and clinical trials focusing on their applications for cartilage regeneration are summarized, and future research perspectives are discussed.

  15. Supernova remnants in the GC region

    Science.gov (United States)

    Asvarov, Abdul

    2016-07-01

    Along with the central Black hole the processes of active star formation play very important role in the energetics of the Galactic center region. The SNe and their remnants (SNRs) are the main ingredients of the processes of star formation. SNRs are also the sources of electromagnetic radiation of all wavelengths from the optical to hard gamma rays. In the presented work we consider the physics of supernova remnants evolving in extreme environmental conditions which are typical for the region of the Galactic center. Because of the high density and strong inhomogeneity of the surrounding medium these objects remain practically invisible at almost all wavelengths. We model evolution of SNR taking into account the pressure of the surrounding medium and the gravitational field of the matter (stars, compact clouds, dark matter) inside the remnant. As it is well established, considerable portion of the kinetic energy of the SNR can be converted into the cosmic ray particles by diffusive shock acceleration mechanism. Therefore the effect of particle acceleration is also included in the model (with the effectiveness of acceleration as a free parameter). Using the observed radiation fluxes at different wavelengths we attempt to obtain limits on the parameters of the model of the Galactic Center, namely, the frequency of star birth, the average density of the matter and radiation field, etc.

  16. THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Acero, F.; Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d’Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Ackermann, M.; Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Blandford, R. D.; Bloom, E. D.; Bottacini, E.; Caliandro, G. A.; Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Bonino, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bregeon, J. [Laboratoire Univers et Particules de Montpellier, Université Montpellier, CNRS/IN2P3, Montpellier (France); Bruel, P., E-mail: francesco.depalma@ba.infn.it, E-mail: t.j.brandt@nasa.gov, E-mail: john.w.hewitt@unf.edu [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France); and others

    2016-05-01

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.

  17. Radio evolution of young supernova remnants

    International Nuclear Information System (INIS)

    Shirkey, R.C. Jr.

    1976-01-01

    A one dimensional spherically symmetric magnetohydrodynamic code was developed to describe the evolution of the dynamical and radio properties of young supernova remnants. The code contains subroutines which treat the development of Rayleigh-Taylor instabilities wherever they arise in the remnant. Under the assumption of quasi-stationary equilibrium (dynamical changes considered slow in comparison to the time it takes the instability to achieve equilibrium) determined that the velocity of the instability is W approximately (a lambda)/sup 1 / 2 /, where a is the Rayleigh-Taylor acceleration and lambda is the wavelength of the instability. Subsequent processing of the kinetic energy of expansion, through turbulence, resulted in an increase in temperature and magnetic field strength. The model was used to analyze instability effects of density inhomogeneities in the interstellar medium on magnetic field amplification. A model was constructed for Cassiopeia A which gave good agreement with the measured dynamics, radio structure, and secular flux density decrease for the remnant. In order to compare observation with theory a computer routine was written that convolves the surface brightness at the source. The resultant convolved surface brightness graph is in good agreement with Rosenberg's observed ''model profile;'' differences between the graphs can be attributed to the asymmetric expansion of Cassiopeia A

  18. Peritoneal Fluid Analysis

    Science.gov (United States)

    ... Get Tested? To help diagnose the cause of peritonitis, an inflammation of the membrane lining the abdomen, ... fever and your healthcare practitioner suspects you have peritonitis or ascites Sample Required? A peritoneal fluid sample ...

  19. Supernova Remnants with Fermi Large Area Telescope

    Directory of Open Access Journals (Sweden)

    Caragiulo M.

    2017-01-01

    Full Text Available The Large Area Telescope (LAT, on-board the Fermi satellite, proved to be, after 8 years of data taking, an excellent instrument to detect and observe Supernova Remnants (SNRs in a range of energies running from few hundred MeV up to few hundred GeV. It provides essential information on physical processes that occur at the source, involving both accelerated leptons and hadrons, in order to understand the mechanisms responsible for the primary Cosmic Ray (CR acceleration. We show the latest results in the observation of Galactic SNRs by Fermi-LAT.

  20. Runaway companions of supernova remnants with Gaia

    Science.gov (United States)

    Boubert, Douglas; Fraser, Morgan; Evans, N. Wyn

    2018-04-01

    It is expected that most massive stars have companions and thus that some core-collapse supernovae should have a runaway companion. The precise astrometry and photometry provided by Gaia allows for the systematic discovery of these runaway companions. We combine a prior on the properties of runaway stars from binary evolution with data from TGAS and APASS to search for runaway stars within ten nearby supernova remnants. We strongly confirm the existing candidate HD 37424 in S147, propose the Be star BD+50 3188 to be associated with HB 21, and suggest tentative candidates for the Cygnus and Monoceros Loops.

  1. VHE Gamma-ray Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Funk, Stefan; /KIPAC, Menlo Park

    2007-01-22

    Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

  2. On neutron star/supernova remnant associations

    OpenAIRE

    Gvaramadze, V. V.

    2000-01-01

    It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1757-24, SGR0525-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possibl...

  3. Remnant cholesterol as a cause of ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Nordestgaard, Børge G

    2014-01-01

    This review focuses on remnant cholesterol as a causal risk factor for ischemic heart disease (IHD), on its definition, measurement, atherogenicity, and levels in high risk patient groups; in addition, present and future pharmacological approaches to lowering remnant cholesterol levels...... are considered. Observational studies show association between elevated levels of remnant cholesterol and increased risk of cardiovascular disease, even when remnant cholesterol levels are defined, measured, or calculated in different ways. In-vitro and animal studies also support the contention that elevated...... levels of remnant cholesterol may cause atherosclerosis same way as elevated levels of low-density lipoprotein (LDL) cholesterol, by cholesterol accumulation in the arterial wall. Genetic studies of variants associated with elevated remnant cholesterol levels show that an increment of 1mmol/L (39mg...

  4. Are crab-type supernova remnants (plerions) short-lived

    International Nuclear Information System (INIS)

    Weiler, K.W.; Panagia, N.

    1978-01-01

    Arguments are given for a possible picture of the origin, maintenance, and lifetimes of the so-called Crab-like supernova remnants. It is suggested that these objects imply the existence of at least two distinct types of supernova events. A possible connection of the remnant types with the optically defined supernovae of Type I and Type II is discussed. Accepting that a pulsar is formed in at least some supernova events, the proposal is made that a rapidly rotating, rapidly slowing pulsar is necessary to create and maintain a Crab-like supernova remnant. Finally, arguments are presented that such a supernova remnant will be relatively short lived with respect to the more common shell-type of supernova remnant, perhaps surviving only 10000-20000 yr before fading into the Galactic background. The name of plerion is proposed for these filled-center supernova remnants and observational possiblities for confirming their nature are suggested. (orig.) [de

  5. PVC membrane, coated-wire, and carbon-paste ion-selective electrodes for potentiometric determination of galantamine hydrobromide in physiological fluids.

    Science.gov (United States)

    Abdel-Haleem, Fatehy M; Saad, Mohamed; Barhoum, Ahmed; Bechelany, Mikhael; Rizk, Mahmoud S

    2018-08-01

    We report on highly-sensitive ion-selective electrodes (ISEs) for potentiometric determining of galantamine hydrobromide (GB) in physiological fluids. Galantamine hydrobromide (GB) was selected for this study due to its previous medical importance for treating Alzheimer's disease. Three different types of ISEs were investigated: PVC membrane electrode (PVCE), carbon-paste electrode (CPE), and coated-wire electrode (CWE). In the construction of these electrodes, galantaminium-reineckate (GR) ion-pair was used as a sensing species for GB in solutions. The modified carbon-paste electrode (MCPE) was prepared using graphene oxide (MCPE-GO) and sodium tetrakis (trifluoromethyl) phenyl borate (MCPE-STFPB) as ion-exchanger. The potentiometric modified CPEs (MCPE-GO and MCPE-STFPB) show an improved performance in term of Nernstian slope, selectivity, response time, and response stability compared to the unmodified CPE. The prepared electrodes PVCE, CWE, CPE, MCPE-GO and MCPE-STFPB show Nernstian slopes of 59.9, 59.5, 58.1, 58.3 and 57.0 mV/conc. decade, and detection limits of 5.0 × 10 -6 , 6.3 × 10 -6 , 8.0 × 10 -6 , 6.0 × 10 -6 and 8.0 × 10 -6  mol L -1 , respectively. The prepared ISEs also show high selectivity against cations (i.e. Na + , K + , NH 4 + , Ca 2+ , Al 3+ , Fe 3+ ), amino acids (i.e. glycine, L-alanine alanine), and sugars (i.e. fructose, glucose, maltose, lactose). The prepared ISEs are applicable for determining GB in spiked serums, urines, and pharmaceutical preparations, using a standard addition and a direct potentiometric method. The fast response time (<10 s), long lifetime (1-5 weeks), reversibility and stability of the measured signals facilitate the application of these sensors for routine analysis of the real samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Urachal remnant carcinoma - a rare entity

    Directory of Open Access Journals (Sweden)

    Vanesha Naidu

    2013-06-01

    Full Text Available Primary malignancy of the urachal remnant is a rare neoplasm that accounts for less than 0.01% of all adult cancers, with an estimated annual incidence of 1:5 million. The tumour carries a grave prognosis that attests to its highly aggressive nature. Owing to its extra-peritoneal location, the tumour runs a relatively silent clinical course until late presentation, when most patients display extensive local invasion and metastatic spread. In this report, we highlight a case of primary malignancy of the urachus that on initial clinical evaluation masqueraded as a Sister Mary Joseph’s nodule. Characteristic imaging features, however, proved decisive in establishing the diagnosis of a urachal carcinoma.

  7. A Python Calculator for Supernova Remnant Evolution

    Science.gov (United States)

    Leahy, D. A.; Williams, J. E.

    2017-05-01

    A freely available Python code for modeling supernova remnant (SNR) evolution has been created. This software is intended for two purposes: to understand SNR evolution and to use in modeling observations of SNR for obtaining good estimates of SNR properties. It includes all phases for the standard path of evolution for spherically symmetric SNRs. In addition, alternate evolutionary models are available, including evolution in a cloudy ISM, the fractional energy-loss model, and evolution in a hot low-density ISM. The graphical interface takes in various parameters and produces outputs such as shock radius and velocity versus time, as well as SNR surface brightness profile and spectrum. Some interesting properties of SNR evolution are demonstrated using the program.

  8. THE DRESSMAKER, REMNANTS OF A LIFE

    DEFF Research Database (Denmark)

    Carpe Pérez, Inmaculada Concepción

    2015-01-01

    The Dressmaker, remnants of a life, is a visual representation of our research in animation ,at the Animated Learning Lab, as a means of reflection on the construction of the self and memories. Through the artistic production of motion pictures, an introspection is done in the author’s personal...... knowledge, which help us to reflect upon thoughts, feelings and actions (personal or external). Such experiences shape our personalities and whose emotional balance our happiness depends on. Memories are the left over product out of experiences, constituents of a reality. This is seen and created...... the psychology of the self. Animation, for it’s metaphorical power and playfulness: mix of reality and fantasy, results a very attractive and effective tool to explore different points of view and work the neuroplasticity, facilitator of the physical changes of our brain and our behavior, area of study...

  9. Exosat observations of the Kepler supernova remnant

    International Nuclear Information System (INIS)

    Smith, A.; Peacock, A.; Arnaud, M.; Ballet, J.; Rothenflug, R.

    1989-01-01

    The medium-energy experiment on board Exosat was used to measure the X-ray spectrum of the Kepler supernova remnant over the range 1.5-10 keV. An Fe emission line was clearly resolved with an energy of about 6.5 keV and equivalent width of about 1.8 keV. This was superposed on a continuum with a temperature of 5.0(+3.8, -1.9) keV. The medium-energy spectrum is shown to be consistent with a model in which the Kepler SNR is presently in a Sedov phase of evolution, the 5 keV continuum arises from the shocked interstellar/circumstellar medium, and thermal (but not ionization) equilibrium exists between electrons and ions behind the primary shock front. However, in this case, an overabundance of iron by more than 6 times cosmic is required. 28 refs

  10. On Neutron Star/Supernova Remnant Association

    Science.gov (United States)

    Gvaramadze, V. V.

    It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1706-44, PSR B1757-24, SGR 0526-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possible NS/SNR associations could be enlarged. An observational test is discussed, which could provide a determination of the true birth-places of NSs associated with middle-aged SNRs, and thereby provide more reliable estimates of their transverse velocities.

  11. An adaptive meshfree method for phase-field models of biomembranes. Part II: A Lagrangian approach for membranes in viscous fluids

    OpenAIRE

    Peco, C.; Rosolen, A.; Arroyo, M.

    2013-01-01

    We present a Lagrangian phase-field method to study the low Reynolds number dynamics of vesicles embedded in a viscous fluid. In contrast to previous approaches, where the field variables are the phase-field and the fluid velocity, here we exploit the fact that the phasefield tracks a material interface to reformulate the problem in terms of the Lagrangian motion of a background medium, containing both the biomembrane and the fluid. We discretize the equations in space with maximum-entr...

  12. Remnants of occipital vertebrae: proatlas segmentation abnormalities.

    Science.gov (United States)

    Menezes, Arnold H; Fenoy, Kathleen A

    2009-05-01

    Developmental remnants around the foramen magnum, or proatlas segmentation abnormalities, have been recorded in postmortem studies but very rarely in a clinical setting. Because of their rarity, the pathological anatomy has been misunderstood, and treatment has been fraught with failures. The objectives of this prospective study were to understand the correlative anatomy, pathology, and embryology and to recognize the clinical presentation and gain insights on the treatment and management. Our craniovertebral junction (CVJ) database started in 1977 and comprises 5200 cases. This prospective study has retrieval capabilities. Neurodiagnostic studies changed with the evolution of imaging. Seventy-two patients were recognized as having symptomatic proatlas segmentation abnormalities. Ventral bony masses from the clivus or medial occipital condyle occurred in 66% (44/72), lateral or anterolateral compressive masses in 37% (27 of 72 patients), and dorsal bony compression in 17% (12 of 72 patients). Hindbrain herniation was associated in 33%. The age at presentation was 3 to 23 years. Motor symptoms occurred in 72% (52 of 72 patients); palsies in Cranial Nerves IX, X, and XII in 33% (24 of 72 patients); and vertebrobasilar symptoms in 25% (18 of 72 patients). Trauma precipitated symptoms in 55% (40 of 72 patients). The best definition of the abnormality was demonstrated by 3-dimensional computed tomography combined with magnetic resonance imaging. Treatment was aimed at decompression of the pathology and stabilization. Remnants of the occipital vertebrae around the foramen magnum were recognized in 72 of 5200 CVJ cases (7.2%). Magnetic resonance imaging with 3-dimensional computed tomography of the CVJ provides the best definition and understanding of the lesions. Brainstem myelopathy and lower cranial nerve deficits are common clinical presentations in the first and second decades of life. Treatment is aimed at decompression of the pathology and CVJ stabilization.

  13. Benner's remnants: culture, tradition and everyday understanding.

    Science.gov (United States)

    Paley, John

    2002-06-01

    Benner's account of meaning and embodiment in nursing depends on a theory which she has never fully articulated, although she makes numerous allusions to it. Behind the background of shared meanings hovers something called 'culture', which provides each individual with meaning, determines what counts as real for her, and actively hands down interpretation-laden practices. This view is based, Benner claims, on the Heideggerian assumption that the meaning and organization of a culture precedes individual meaning-giving activity. I explore Benner's implicit view of culture, drawing on her published work over 15 years, and offer an appraisal of it. In doing so, I attempt to make sense of some rather strange remarks Benner has recently made about 'remnants' of Cartesian and Kantian thinking being found in the everyday understandings of people with asthma. The concept of culture is developed with reference to both Benner's own work and that of the anthropologist, Clifford Geertz, whose work she frequently cites. Having identified the principal tenets of what we might conveniently call the Benner-Geertz theory, I proceed to interrogate the theory, using the recent anthropological literature -- and, in particular, materialist attacks on the idea of culture as a system of meanings -- in order to cast doubt on it. I also review, very briefly, an alternative way of understanding 'culture', which is not vulnerable to the same criticisms. Benner's implicit theory of culture is revealed, somewhat ironically, as an inverted form of Cartesian dualism. Its intellectual provenance is not Heidegger, who appears to reject it, but the sort of American sociology associated with Talcott Parsons. As a corollary, it is suggested that Benner's 'remnants' analogy cannot be justified, and that the idea of Cartesian and Kantian concepts permeating Western culture, infecting both the providers and receivers of health care, is a myth.

  14. Supernova remnants and the origin of cosmic rays

    NARCIS (Netherlands)

    Vink, J.

    2014-01-01

    Supernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the

  15. Supernova Remnants as the Sources of Galactic Cosmic Rays

    NARCIS (Netherlands)

    Vink, J.

    2013-01-01

    The origin of cosmic rays holds still manymysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate

  16. Relating Eye Activity Measures to Human Controller Remnant Characteristics

    NARCIS (Netherlands)

    Popovici, A; Zaal, P.M.T.; Pool, D.M.; Mulder, M.; Sawaragi, T

    2016-01-01

    This study attempts to partially explain the characteristics of the human perceptual remnant, following Levison’s representation of the remnant as an equivalent observation noise. Eye activity parameters are recorded using an eye tracker in two compensatory tracking tasks in which the visual

  17. Acoustic concentration of particles in fluid flow

    Science.gov (United States)

    Ward, Michael D.; Kaduchak, Gregory

    2010-11-23

    An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

  18. Acoustic concentration of particles in fluid flow

    Science.gov (United States)

    Ward, Michael W.; Kaduchak, Gregory

    2017-08-15

    Disclosed herein is a acoustic concentration of particles in a fluid flow that includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

  19. [Recurrent neck abscess due to a branchial cleft remnant].

    Science.gov (United States)

    Kruijff, Schelto; Mastboom, Walter J; Vriens, Menno R; Sidhu, Stan B; Delbridge, Leigh W

    2013-01-01

    Abscesses arising from a third or fourth branchial cleft remnant are uncommon clinical entities and are often not recognised in a timely manner. In a 33-year-old female patient with a recurrent abscess in the left side of her neck, the cause turned out to be a fistula in the third branchial cleft remnant. She was treated initially with antibiotics and prednisone without adequate results. When the abscess was finally surgically drained, she became very ill and was admitted to the ICU with sepsis and multiple organ failure. She was discharged from hospital after six weeks. Four months later, a third-branchial cleft remnant was found during pharyngoscopy, immediately after which the cleft remnant fistula was excised and an ipsilateral hemi-thyroidectomy was performed. In young patients with recurring peri-thyroidal abscesses, a branchial cleft remnant should be considered a causative factor; this could avoid high morbidity and a delay in the appropriate treatment.

  20. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans

    NARCIS (Netherlands)

    Bernelot Moens, Sophie J.; Verweij, Simone L.; Schnitzler, Johan G.; Stiekema, Lotte C. A.; Bos, Merijn; Langsted, Anne; Kuijk, Carlijn; Bekkering, Siroon; Voermans, Carlijn; Verberne, Hein J.; Nordestgaard, Børge G.; Stroes, Erik S. G.; Kroon, Jeffrey

    2017-01-01

    Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation,

  1. Generation of Cosmic rays in Historical Supernova Remnants

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.Y.

    2013-06-01

    Full Text Available We present the results of observations of two types of Galactic supernova remnants with the SHALON mirror Cherenkov telescope of Tien-Shan high-mountain Observatory: the shell-type supernova remnants Tycho, Cas A and IC 443; plerions Crab Nebula, 3c58(SN1181 and Geminga (probably plerion. The experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy (800 GeV - 100 TeV gamma-rays in Tycho's supernova remnant. The data obtainedsuggest that the very high energy gamma-ray emission in the objects being discussedis different in origin.

  2. Revised Distances to 21 Supernova Remnants

    Science.gov (United States)

    Ranasinghe, S.; Leahy, D. A.

    2018-05-01

    We carry out a comprehensive study of H I 21 cm line observations and 13CO line observations of 21 supernova remnants (SNRs). The aim of the study is to search for H I absorption features to obtain kinematic distances in a consistent manner. The 21 SNRs are in the region of sky covered by the Very Large Array Galactic Plane Survey (H I 21 cm observations) and Galactic Ring Survey (13CO line observations). We obtain revised distances for 10 SNRs based on new evidence in the H I and 13CO observations. We revise distances for the other 11 SNRs based on an updated rotation curve and new error analysis. The mean change in distance for the 21 SNRs is ≃25%, i.e., a change of 1.5 kpc compared to a mean distance for the sample of 6.4 kpc. This has a significant impact on interpretation of the physical state of these SNRs. For example, using a Sedov model, age and explosion energy scale as the square of distance, and inferred ISM density scales as distance.

  3. Quantum remnants in the classical limit

    International Nuclear Information System (INIS)

    Kowalski, A.M.; Plastino, A.

    2016-01-01

    We analyze here the common features of two dynamical regimes: a quantum and a classical one. We deal with a well known semi-classic system in its route towards the classical limit, together with its purely classic counterpart. We wish to ascertain i) whether some quantum remnants can be found in the classical limit and ii) the details of the quantum-classic transition. The so-called mutual information is the appropriate quantifier for this task. Additionally, we study the Bandt–Pompe's symbolic patterns that characterize dynamical time series (representative of the semi-classical system under scrutiny) in their evolution towards the classical limit. - Highlights: • We investigate the classical limit (CL) of a well known semi classical model. • The study is made by reference to the Bandt Pompe symbolic approach. • The number and type of associated symbols changes as one proceeds towards the CL. • We ascertain which symbols pertaining to the quantum zone remain in the CL.

  4. Nonthermal Radiation from Supernova Remnant Shocks

    Directory of Open Access Journals (Sweden)

    Hyesung Kang

    2013-09-01

    Full Text Available Most of high energy cosmic rays (CRs are thought to be produced by diffusive shock acceleration (DSA at supernova remnants (SNRs within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the timedependent evolution of the self-amplified magnetic fields, Alfvénic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and γ-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

  5. Radio emission from embryonic superluminous supernova remnants

    Science.gov (United States)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  6. Quantum remnants in the classical limit

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, A.M., E-mail: kowalski@fisica.unlp.edu.ar [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Comision de Investigaciones Científicas (CIC) (Argentina); Plastino, A., E-mail: plastino@fisica.unlp.edu.ar [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Argentina' s National Research Council (CONICET) (Argentina); SThAR, EPFL Innovation Park, Lausanne (Switzerland)

    2016-09-16

    We analyze here the common features of two dynamical regimes: a quantum and a classical one. We deal with a well known semi-classic system in its route towards the classical limit, together with its purely classic counterpart. We wish to ascertain i) whether some quantum remnants can be found in the classical limit and ii) the details of the quantum-classic transition. The so-called mutual information is the appropriate quantifier for this task. Additionally, we study the Bandt–Pompe's symbolic patterns that characterize dynamical time series (representative of the semi-classical system under scrutiny) in their evolution towards the classical limit. - Highlights: • We investigate the classical limit (CL) of a well known semi classical model. • The study is made by reference to the Bandt Pompe symbolic approach. • The number and type of associated symbols changes as one proceeds towards the CL. • We ascertain which symbols pertaining to the quantum zone remain in the CL.

  7. Predicting gravitational lensing by stellar remnants

    Science.gov (United States)

    Harding, Alexander J.; Stefano, R. Di; Lépine, S.; Urama, J.; Pham, D.; Baker, C.

    2018-03-01

    Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper, we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, five black holes, and ≈35 000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here, we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With Hubble Space Telescope, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets.

  8. Timing of Histologic Progression from Chorio-Deciduitis to Chorio-Deciduo-Amnionitis in the Setting of Preterm Labor and Preterm Premature Rupture of Membranes with Sterile Amniotic Fluid.

    Science.gov (United States)

    Park, Chan-Wook; Park, Joong Shin; Norwitz, Errol R; Moon, Kyung Chul; Jun, Jong Kwan; Yoon, Bo Hyun

    2015-01-01

    Histologic chorio-deciduitis and chorio-deciduo-amnionitis (amnionitis) in extra-placental membranes are known to represent the early and advanced stages of ascending intra-uterine infection. However, there are no data in humans about the time required for chorio-deciduitis to develop and for chorio-deciduitis without amnionitis to progress to chorio-deciduitis with amnionitis, and the effect of prolongation of pregnancy on the development of chorio-deciduitis and amnionitis in patients with preterm labor and intact membranes (PTL) and preterm premature rupture of membranes (preterm-PROM). We examined these issues in this study. The study population consisted of 289 women who delivered preterm (133 cases with PTL, and 156 cases with preterm-PROM) and who had sterile amniotic fluid (AF) defined as a negative AF culture and the absence of inflammation as evidenced by a matrix metalloproteinase-8 (MMP-8) level membranes (i.e., inflammation-free extra-placental membranes, choroi-deciduitis only, and chorio-deciduitis with amnionitis) in patients with PTL and preterm-PROM. Amniocentesis-to-delivery interval was longer in cases of chorio-deciduitis with amnionitis than in cases of chorio-deciduitis only in both PTL (median [interquartile-range (IQR)]; 645.4 [319.5] vs. 113.9 [526.9] hours; P = 0.005) and preterm-PROM (131.3 [135.4] vs. 95.2 [140.5] hours; Pmembranes. Moreover, prolongation of pregnancy is an independent predictor of the development of both chorio-deciduitis and amnionitis in cases of PTL with sterile AF.

  9. Fluid Shifts

    Science.gov (United States)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; hide

    2017-01-01

    pulsatility); (5) ocular measures (optical coherence tomography; intraocular pressure; 2-dimensional ultrasound including optic nerve sheath diameter, globe flattening, and retina-choroid thickness; Doppler ultrasound of ophthalmic and retinal arteries and veins); (6) cardiac variables by ultrasound (inferior vena cava, tricuspid flow and tissue Doppler, pulmonic valve, stroke volume, right heart dimensions and function, four-chamber views); and (7) ICP measures (tympanic membrane displacement, otoacoustic emissions). Pre- and post-flight, acute head-down tilt will induce cephalad fluid shifts, whereas lower body negative pressure will oppose these shifts. Controlled Mueller maneuvers will manipulate cardiovascular variables. Through interventions applied before, during, and after flight, we intend to fully evaluate the relationship between fluid shifts and the VIIP syndrome. Discussion. Ten subjects have consented to participate in this experiment, including the recent One-Year Mission crewmembers, who have recently completed R plus180 testing; all other subjects have completed pre-flight testing. Preliminary results from the One-Year Mission crewmembers will be presented, including measures of ocular structure and function, vascular dimensions, fluid distribution, and non-invasive estimates of intracranial pressure.

  10. Cystic duct remnant mucocele in a liver transplant recipient

    Energy Technology Data Exchange (ETDEWEB)

    Ahlawat, Sushil K. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ (United States); Fishbien, Thomas M. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); Haddad, Nadim G. [Georgetown University Hospital, Department of Surgery, Division of Transplant Surgery, Washington, DC (United States)

    2008-08-15

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  11. Cystic duct remnant mucocele in a liver transplant recipient

    International Nuclear Information System (INIS)

    Ahlawat, Sushil K.; Fishbien, Thomas M.; Haddad, Nadim G.

    2008-01-01

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  12. Hydrodynamic Simulations of Kepler's Supernova Remnant

    Science.gov (United States)

    Sullivan, Jessica; Blondin, John; Borkowski, Kazik; Reynolds, Stephen

    2018-01-01

    Kepler’s supernova remnant contains unusual features that strongly suggest an origin in a single-degenerate Type Ia explosion, including anisotropic circumstellar medium (CSM), a strong brightness gradient, and spatially varying expansion proper motions. We present 3Dhydrodynamic simulations to test a picture in which Kepler's progenitor binary emitted a strong asymmetric wind, densest in the orbital plane, while the system moved at high velocity through the ISM. We simulate the creation of the presupernova environment as well as the supernova blast wave, using the VH-1 grid-based hydrodynamics code. We first modeled an anisotropic wind to create an asymmetric bowshock around the progenitor, then the blast wave from thesupernova. The final simulation places both previous model pieces onto a single grid and allows the blast wave to expand into the bowshock. Models were completed on a Yin-Yang grids with matching angular resolutions. By manipulating parameters that control the asymmetry of the system, we attempted to find conditions that recreated the current state of Kepler. We analyzed these models by comparing images of Kepler from the Chandra X-ray Observatory to line-of-sight projections from the model results. We also present comparisons of simulated expansion velocities with recent observations of X-ray proper motions from Chandra images. We were able to produce models that contained similar features to those seen in Kepler. We find the greatest resemblance to Kepler images with a presupernova wind with an equator-to-pole density contrast of 3 and a moderately disk-like CSM at a 5° angle between equatorial plane and system motion.

  13. Supernova Remnant Observations with Micro-X

    Science.gov (United States)

    Figueroa, Enectali

    Micro-X is a sounding rocket payload that combines an X-ray microcalorimeter with an imaging mirror to offer breakthrough science from high spectral resolution observations of extended X-ray sources. This payload has been in design and development for the last five years and is now completely built and undergoing integration; its first flight will be in November, 2012, as part of our current NASA award. This four-year follow-on proposal seeks funding for: (1) analysis of the first flight data, (2) the second flight and its data analysis, (3) development of payload upgrades and launch of the third flight, and (4) third flight data analysis. The scientific payload consists of a Transition Edge Sensor (TES) microcalorimeter array at the focus of a flight-proven conical imaging mirror. Micro-X capitalizes on three decades of NASA investment in the development of microcalorimeters and X-ray imaging optics. Micro-X offers a unique combination of bandpass, collecting area, and spectral and angular resolution. The spectral resolution goal across the 0.2 - 3.0 keV band is 2 - 4 eV Full-Width at Half Maximum (FWHM). The measured angular resolution of the mirror is 2.4 arcminute Half-Power Diameter (HPD). The effective area of the mirror, 300 square centimeters at 1 keV, is sufficient to provide observations of unprecedented quality of several astrophysical X-ray sources, even in a brief sounding rocket exposure of 300 sec. Our scientific program for this proposal will focus on supernova remnants (SNRs), whose spatial extent has made high-energy resolution observations with grating instruments extremely challenging. X-ray observations of SNRs with microcalorimeters will enable the study of the detailed atomic physics of the plasma; the determination of temperature, turbulence, and elemental abundances; and in conjunction with historical data, full three dimensional mapping of the kinematics of the remnant. These capabilities will open new avenues towards understanding the

  14. SUPERNOVA REMNANT PROGENITOR MASSES IN M31

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R. [Department of Astronomy, University of Washington Seattle, Box 351580, WA 98195 (United States); Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolphin, Andrew E., E-mail: zachjenn@uw.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States)

    2012-12-10

    Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a

  15. Complex structure of the supernova remnant HB 3

    Science.gov (United States)

    Leahy, D. A.; Venkatesan, D.; Long, K. S.; Naranan, S.

    1985-01-01

    HB 3 is an old, large (84 pc diameter) supernova remnant associated with the W3 H II region/molecular cloud complex. Observations of the imaging proportional counter (IPC) onboard the Einstein X-ray astronomy satellite have been reprocessed to yield a contour map of X-ray brightness and spectra of various regions of this remnant. The measured IPC flux is 2.4 x 10 to the -11th ergs per sq cm per s, giving a 0.2-4 keV luminosity of 1.6 x 10 to the 35th ergs/s for a column densityof 6 x 10 to the 21st per sq cm. The measured X-ray temperatures reveal a decrease from center to limb of the remnant of 1-0.3 keV. HB 3 is in the late adiabatic blast-wave phase of evolution, 30,000 to 50,000 yr old and with an initial blast energy of 3 x 10 to the 50th ergs. The X-ray map is compared with available radio and optical images. In X-rays, HB 3 has two components - a diffuse emission inside the 84 pc radio remnant and a ring of emission at the center of 30 pc in diameter. The diffuse emission is similar to that from other supernova remnants which are moderately obscured (column density, nH approximately 10 to the 22nd per sq cm). Three possibilities for the origin of the ring are explored: (1) a second supernova remnant, (2) a shocked shell in the interstellar medium surrounding HB 3, and (3) reverse-shock heated ejecta. There is no hot neutron star within the remnant.

  16. Fluid migration through geo-membrane seams and through the interface between geo-membrane and geo-synthetic clay liner; Contribution a l'etude des transferts de masse au niveau des joints de geomembrane et a l'interface entre geomembrane et geosynthetique bentonitique

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, M

    2005-03-15

    Composite liners are used to limit the contamination migration from landfills. Their successful performance is closely related with the geo-membrane as it provides the primary barrier to diffusive and advective transport of contaminants. Critical issues on the performance of the geo-membranes are the seams between geo-membrane panels and the inevitable defects resulting, for instance, from inadequate installation activities. In landfills, where high density polyethylene geo-membranes are usually used, seams are typically made by the thermal-hot dual wedge method. A literature review on quality control of the seams showed that, in situ, fluid-tightness of seams is evaluated in qualitative terms (pass/failure criteria), despite their importance to ensure appropriate performance of the geo-membranes as barriers. In addition, a synthesis of studies on geo-membrane defects indicated that defects varying in density from 0.7 to 15.3 per hectare can be found in landfills. Defects represent preferential flow paths for leachate. Various authors have developed analytical solutions and empirical equations for predicting the flow rate through composite liners due to defects in the geo-membrane. The validity of these methods for composite liners comprising a geo-membrane over a geo-synthetic clay liner (GCL) over a compacted clay liner (CCL) has never been studied from an experimental point of view. To address the problem of fluid migration through the geo-membrane seams, an attempt is made to provide a test method, herein termed as 'gas permeation pouch test', for assessing the quality of the thermal-hot dual wedge seams. This test consists of pressurizing the air channel formed by the double seam with a gas to a specific pressure and, then, measuring the decrease in pressure over time. From the pressure decrease, both the gas permeation coefficients, in steady state conditions, and the time constant, in unsteady state conditions, can be estimated. Experiments were

  17. Black hole remnants and the information loss paradox

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P., E-mail: pisinchen@phys.ntu.edu.tw [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Graduate Institute of Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, CA 94305 (United States); Ong, Y.C., E-mail: yenchin.ong@nordita.org [Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Yeom, D.-H., E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)

    2015-11-22

    Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a “remnant” has remained unpopular and is often dismissed due to some “undesired properties” of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of the information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singularity is also emphasized, after all there remains a possibility that the singularity cannot be cured even by quantum gravity. In this context a black hole remnant conveniently serves as a cosmic censor. We conclude that a remnant remains a possible end state of Hawking evaporation, and if it contains large interior geometry, may help to ameliorate the information loss paradox and the firewall controversy. We hope that this will raise some interests in the community to investigate remnants more critically but also more thoroughly.

  18. Black hole remnants and the information loss paradox

    International Nuclear Information System (INIS)

    Chen, P.; Ong, Y.C.; Yeom, D.-H.

    2015-01-01

    Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a “remnant” has remained unpopular and is often dismissed due to some “undesired properties” of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of the information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singularity is also emphasized, after all there remains a possibility that the singularity cannot be cured even by quantum gravity. In this context a black hole remnant conveniently serves as a cosmic censor. We conclude that a remnant remains a possible end state of Hawking evaporation, and if it contains large interior geometry, may help to ameliorate the information loss paradox and the firewall controversy. We hope that this will raise some interests in the community to investigate remnants more critically but also more thoroughly.

  19. Plasma Membrane Ca2+-ATPase 4 in Murine Epididymis: Secretion of Splice Variants in the Luminal Fluid and a Role in Sperm Maturation1

    OpenAIRE

    Patel, Ramkrishna; Al-Dossary, Amal A.; Stabley, Deborah L.; Barone, Carol; Galileo, Deni S.; Strehler, Emanuel E.; Martin-DeLeon, Patricia A.

    2013-01-01

    Plasma membrane Ca2+-ATPase isoform 4 (PMCA4) is the primary Ca2+ efflux pump in murine sperm, where it regulates motility. In Pmca4 null sperm, motility loss results in infertility. We have shown that murine sperm PMCA4b interacts with Ca2+/CaM-dependent serine kinase (CASK) in regulating Ca2+ homeostasis and motility. However, recent work indicated that the bovine PMCA4a splice variant (missing in testis) is epididymally expressed, along with 4b, and may be transferred to sperm. Here we sho...

  20. Planck intermediate results XXXI. Microwave survey of Galactic supernova remnants

    DEFF Research Database (Denmark)

    Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.

    2016-01-01

    The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for micr......The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism...... for microwave emission. In only one case, IC 443, is there high-frequency emission clearly from dust associated with the supernova remnant. In all cases, the low-frequency emission is from synchrotron radiation. As predicted for a population of relativistic particles with energy distribution that extends...

  1. Layered plasma polymer composite membranes

    Science.gov (United States)

    Babcock, Walter C.

    1994-01-01

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is .gtoreq.2 and is the number of selective layers.

  2. Case report of bilateral cervical chondrocutaneous branchial remnants.

    Science.gov (United States)

    Braun, Hannes; Hofmann, Thiemo; Wolfgruber, Herwig; Anderhuber, Wolfgang; Beham, Alfred; Stammberger, Heinz

    2003-01-01

    Cervical chondrocutaneous branchial remnants are rare and not well known lesions. Histologically the lesion per definition presents as a Choristoma. Choristoma is the pathohistological term for a developmental tumor-like anomaly consisting of tissues foreign to the site at which it is located. Treatment is complete surgical removal as promptly as possible in order to get an exact histopathological diagnosis. A case of a 4-month-old boy with cervical chondrocutaneous branchial remnants anterior to the sternocleidomastoid muscles on both sides is presented. According to literature search this appears to be the second case published on such a bilateral lesion.

  3. The acceleration of cosmic rays in supernova remnants

    International Nuclear Information System (INIS)

    Bhat, C.L.; Issa, M.R.

    1986-01-01

    The idea that the bulk of cosmic rays below 10 GeV are accelerated in supernova remnants suggests that cosmic rays should also exhibit intensity variations on a scale comparable with the linear size of a representative remnant. Following the general spirit of shock-wave acceleration models, here Monte Carlo simulations are carried out to predict what this scale should be and then corroborative evidence is presented from an autocorrelation analysis of the COS B and SAS II γ-ray data for the latitude range |b|=10-20 0 ('near Galaxy') and |b| 0 ('far Galaxy'). (author)

  4. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  5. Cholesteatoma behind an intact tympanic membrane: histopathologic evidence for a tympanic membrane origin.

    Science.gov (United States)

    Sudhoff, H; Linthicum, F H

    2001-07-01

    Several theories have been proposed with respect to the origin and pathogenesis of cholesteatoma behind an intact tympanic membrane. The authors describe a case of cholesteatoma behind an intact tympanic membrane in a 71-year-old man with a history of tympanic membrane retraction fixed to the incus without evidence of a perforation. The membrane eventually became detached, and remnants of keratinizing squamous epithelium were found on the incus. Mechanisms such as metaplasia, ectopic epidermis rests, or ingrowth of meatal epidermis have been proposed to explain the pathogenesis of cholesteatoma behind an intact tympanic membrane. These findings, based on temporal bone histopathology, support the role of an acquired epidermal rest. This case report provides evidence that cholesteatoma behind an intact tympanic membrane can be established from a resolved retraction of the pars tensa of the tympanic membrane.

  6. Probing lipid membrane electrostatics

    Science.gov (United States)

    Yang, Yi

    The electrostatic properties of lipid bilayer membranes play a significant role in many biological processes. Atomic force microscopy (AFM) is highly sensitive to membrane surface potential in electrolyte solutions. With fully characterized probe tips, AFM can perform quantitative electrostatic analysis of lipid membranes. Electrostatic interactions between Silicon nitride probes and supported zwitterionic dioleoylphosphatidylcholine (DOPC) bilayer with a variable fraction of anionic dioleoylphosphatidylserine (DOPS) were measured by AFM. Classical Gouy-Chapman theory was used to model the membrane electrostatics. The nonlinear Poisson-Boltzmann equation was numerically solved with finite element method to provide the potential distribution around the AFM tips. Theoretical tip-sample electrostatic interactions were calculated with the surface integral of both Maxwell and osmotic stress tensors on tip surface. The measured forces were interpreted with theoretical forces and the resulting surface charge densities of the membrane surfaces were in quantitative agreement with the Gouy-Chapman-Stern model of membrane charge regulation. It was demonstrated that the AFM can quantitatively detect membrane surface potential at a separation of several screening lengths, and that the AFM probe only perturbs the membrane surface potential by external field created by the internai membrane dipole moment. The analysis yields a dipole moment of 1.5 Debye per lipid with a dipole potential of +275 mV for supported DOPC membranes. This new ability to quantitatively measure the membrane dipole density in a noninvasive manner will be useful in identifying the biological effects of the dipole potential. Finally, heterogeneous model membranes were studied with fluid electric force microscopy (FEFM). Electrostatic mapping was demonstrated with 50 nm resolution. The capabilities of quantitative electrostatic measurement and lateral charge density mapping make AFM a unique and powerful

  7. Variations in fluid chemistry and membrane phospholipid fatty acid composition of the bacterial community in a cold storage groundwater system during clogging events

    International Nuclear Information System (INIS)

    Vetter, Alexandra; Mangelsdorf, Kai; Wolfgramm, Markus; Rauppach, Kerstin; Schettler, Georg; Vieth-Hillebrand, Andrea

    2012-01-01

    In order to monitor the operating mode of the cold storage of the German Parliament (North German Basin) the fluid chemistry and the phospholipid fatty acid (PLFA) composition of the indigenous microbial community have been monitored from August 2006 to August 2009. During this time two periods of reduced injection (clogging events) characterized by Fe precipitates and microbial biofilms in filters occurred in the injection wells impairing the operating state of the investigated cold storage. The fluid monitoring revealed the presence of sufficient amounts of potential C and energy sources (e.g. DOC and SO 4 2- ) in the process water to sustain microbial life in the cold storage. In times of reduced injection the PLFA inventory of the microbial community differs significantly from times of normal operating phases indicating compositional changes in the indigenous microbial ecosystem. The most affected fatty acids (FAs) are 16:1ω7c (increase), 16:1ω7t (decrease) and 18:1ω7c (increase), interpreted to originate mainly from Fe and S oxidizers, as well as branched FA with 15, 16 and 17 C atoms (decrease) most likely representing sulfate-reducing bacteria (SRB). Based on this variability, PLFA ratios have been created to reflect the increasing dominance of biofilm forming S and Fe oxidizers during the disturbance periods. These ratios are potential diagnostic tools to assess the microbiological contribution to the clogging events and to find appropriate counteractive measures (e.g. mechanical cleaning vs disinfection). The correlation between changes in the PLFA composition and the operational state suggests that microbially mediated processes play a significant role in the observed clogging events in the investigated cold storage.

  8. Nucleated regeneration of semiarid sclerophyllous forests close to remnant vegetation

    NARCIS (Netherlands)

    Fuentes-Castillo, T.; Miranda, A.; Rivera-Hutinel, A.; Smith-Ramirez, C.; Holmgren, M.

    2012-01-01

    Natural regeneration of mediterranean plant communities has proved difficult in all continents. In this paper we assess whether regeneration of sclerophyllous forests shows nucleated patterns indicative of a positive effect of vegetation remnants at the landscape level and compare the regeneration

  9. X-Ray Emission Properties of Supernova Remnants

    NARCIS (Netherlands)

    Vink, J.; Alsabti, A.W.; Murdin, P.

    2016-01-01

    X-ray emission from supernova remnants can be broadly divided into thermal X-ray emission from the shock-heated plasmas and in nonthermal (synchrotron) emission caused by very high-energy (10–100 TeV) electrons moving in the magnetic fields of the hot plasmas. The thermal X-ray emission of young

  10. Supernova remnants, pulsar wind nebulae and their interaction

    NARCIS (Netherlands)

    Swaluw, E. van der

    2001-01-01

    A supernova explosion marks the end of the evolution of a massive star. What remains of the exploded star is a high density neutron star or a black hole. The material which has been ejected by the supernova explosion will manifest itself as a supernova remnant: a hot bubble of gas expanding in the

  11. The origin of radio recombination lines seen toward supernova remnants

    International Nuclear Information System (INIS)

    Pankonin, V.; Downes, D.

    1976-01-01

    New observations have been made of the 166 α spectrum in the direction of the supernova remnants G-0.6 - 0.1, 3 C 391 and W 49 B. The variation of the intensity of the hydrogen recombination lines with frequency indicates that the lines arise in extended, low-density H II regions and not in cold clouds. (orig.) [de

  12. Efficacy of different I-131 doses for thyroid remnant ablation

    International Nuclear Information System (INIS)

    Nguyen, X.C.; Thiep, T.V.; Hung, N.C.

    2007-01-01

    Full text: Radioactive iodine 131 I has been widely used as a treatment modality of differentiated thyroid carcinoma. The need for high dose radioiodine ablation of thyroid remnant is still in question. The aim of this prospective study was to assess the efficacy of 131 I different single and fractionated doses in ablation of post-operative thyroid remnant. Patients and methods: One hundred-twelve patients were included in this study. Sixty-one patients with TSH≥30 μU/ml were treated 30 mCi in group 1 (36 patients) or 100 mCi in group 2 (25 patients). Fifty one patients with TSH 131 I high dose of 100 mCi and no severe adverse effect in the other groups. Conclusion: Single high dose (100 mCi) may be more efficient than single low dose (30 mCi) for post-operative remnant ablation with serum TSH≥30 μU/ml and the efficacy of low fractionated doses (30+30 mCi) was comparable with high-fractionated dose (30+100 mCi) for post-operative remnant ablation with low serum TSH in differentiated thyroid carcinoma. (author)

  13. CASE REPORT Urachal remnant carcinoma - a rare entity

    African Journals Online (AJOL)

    Magnetic resonance imaging (MRI) was not undertaken as it was thought to confer little benefit in the setting of advanced disease. Following histological confirmation of moderately differentiated invasive adenocarcinoma of the urachal remnant, and administration of chemotherapy, the patient developed cerebral metastasis ...

  14. Bat use of remnant old-growth redwood stands

    Science.gov (United States)

    William J. Zielinski; Steven T. Gellman

    1999-01-01

    Most of the old-growth redwood (Sequoia sempervirens) in Calfornia has been cut; regenerating forests will probably never resemble those that were harvested, and what old growth remains on private land occurs in small, isolated remnant patches. The landscapes in which these stands occur differ so markedly from their original condition that their...

  15. Constraining the number of compact remnants near Sgr A*

    Science.gov (United States)

    Deegan, Patrick; Nayakshin, Sergei

    2007-05-01

    Due to dynamical friction stellar mass black holes and neutron stars are expected to form high-density cusps in the inner parsec of our Galaxy. These compact remnants, expected to number around 20000, may be accreting cold dense gas present there, and give rise to potentially observable X-ray emission. Here we build a simple but detailed time-dependent model of such emission. The possibility that these accretion flows are radiatively inefficient is taken into account and brings in some uncertainty in the conclusions. Despite this uncertainty, we find that at least several X-ray sources of this nature should be detectable with Chandra at any one time. Turning this issue around, we also ask a question of what current observational constraints might be telling us about the total number of compact remnants. In our `best guess' model, a cusp of ~40000 remnants overpredicts the number of discrete sources and the total X-ray luminosity of the inner parsec, and is hence ruled out. In the most radiatively inefficient scenario that we consider, the radiative efficiency is set to be as small as ɛ = 10-5. In this rather unlikely scenario, a cusp of ~40000 black holes would be allowed by the data, but several individual sources should still be visible. Future observations of the distribution and orbits of the cold ionized gas in the inner parsec of our Galaxy will put tighter constraints on the cusp of compact remnants.

  16. On The Origin Of Two-Shell Supernova Remnants

    Science.gov (United States)

    Gvaramadze, Vasilii

    2007-07-01

    The proper motion of massive stars could cause them to explode far from the geometric centers of their wind-driven bubbles and thereby could affect the symmetry of the resulting diffuse supernova remnants (SNRs). We use this fact to explain the origin of SNRs consisting of two partially overlapping shells (e.g. Cygnus Loop, 3C 400.2, etc.).

  17. A Recurrent Nova Super-Remnant in the Andromeda Galaxy

    DEFF Research Database (Denmark)

    Darnley, M. J.; Hounsell, R.; O'Brien, T. J.

    2017-01-01

    Here we report that the most rapidly recurring nova, M31N 2008-12a, which erupts annually, is surrounded by a "nova super-remnant" which demonstrates that M31N 2008-12a has erupted with high frequency for millions of years....

  18. Tori sequences as remnants of multiple accreting periods of Kerr SMBHs

    Science.gov (United States)

    Pugliese, D.; Stuchlík, Z.

    2018-03-01

    Super-massive black holes (SMBHs) hosted in active galactic nuclei (AGNs) can be characterized by multi-accreting periods as the attractors interact with the environment during their life-time. These multi-accretion episodes should leave traces in the matter orbiting the attractor. Counterrotating and even misaligned structures orbiting around the SMBHs would be consequences of these episodes. Our task in this work is to consider situations where such accretions occur and to trace their remnants represented by several toroidal accreting fluids, corotating or counterrotating relative to the central Kerr attractor, and created in various regimes during the evolution of matter configurations around SMBHs. We focus particularly on the emergence of matter instabilities, i.e., tori collisions, accretion onto the central Kerr black hole, or creation of jet-like structures (proto-jets). Each orbiting configuration is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluid. We prove that sequences of configurations and hot points, where an instability occurs, characterize the Kerr SMBHs, depending mainly on their spin-mass ratios. The occurrence of tori accretion or collision are strongly constrained by the fluid rotation with respect to the central black hole and the relative rotation with respect to each other. Our investigation provides characteristic of attractors where traces of multi-accreting episodes can be found and observed.

  19. Decrumpling membranes by quantum effects

    Science.gov (United States)

    Borelli, M. E. S.; Kleinert, H.

    2001-02-01

    The phase diagram of an incompressible fluid membrane subject to quantum and thermal fluctuations is calculated exactly in a large number of dimensions of configuration space. At zero temperature, a crumpling transition is found at a critical bending rigidity 1/αc. For membranes of fixed lateral size, a crumpling transition occurs at nonzero temperatures in an auxiliary mean field approximation. As the lateral size L of the membrane becomes large, the flat regime shrinks with 1/ln L.

  20. Cervical chondrocutaneous branchial remnants--report of 17 cases.

    Science.gov (United States)

    Begovic, Ninoslav; Simic, Radoje; Vlahovic, Aleksandar; Kravljanac, Djordje; Djuricic, Slavisa; Mijovic, Tanja

    2014-11-01

    Cervical chondrocutaneous branchial remnants are congenital, benign and rare neck masses. These anomalies are limited in the literature, reported mostly as case reports. Cervical chondrocutaneous branchial remnant is always present at birth, and the lesion is usually unilateral. Understanding and treatment of cervical chondrocutaneous branchial remnants requires knowledge of the related embryology. From January 2005 to December 2008, 17 patients with mean age of 32 months (range from 2 months to 15 years) with CCBRs were treated at the Division of Pediatric Surgery, Department of Plastic and Reconstructive Surgery and Burns at the Institute for Mother and Child Health Care, Belgrade, Serbia. The following objections were recorded: sex, lesion side, surgical data, associated malformations and pathohistology findings. There were 7 females and 10 males, 4 with bilateral presences. Five children had associated anomalies, as follows: vesicoureteral reflux, atrial and ventricular septal defect, ventricular septal defect, branchiootorenal syndrome and preauricular sinus. There was a positive family history in one patient. Fifteen patients (88%) were treated with complete surgical excision and no connections with deep underlying structures of the neck were found. There were no complications at surgery. No recurrence was found during follow-up. Histopathology analysis revealed both, hyaline and elastic cartilage. Cervical chondrocutaneous branchial remnants are rare anomalies arising from branchial arch, probably originally from remnants of first or second arch. Surgical excision is the treatment of choice. From our experience, we suggest surgical treatment early in childhood because of esthetic reason, simplicity of the intervention and low complication rate. Also, the abdominal ultrasound and cardiac examination is recommended because of associated anomalies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Hot interstellar tunnels. I. Simulation of interacting supernova remnants

    International Nuclear Information System (INIS)

    Smith, B.W.

    1977-01-01

    Reexamining a suggestion of Cox and Smith, we find that intersecting supernova remnants can indeed generate and maintain hot interstellar regions with napproximately-less-than10 -2 cm -3 and Tapprox.10 6 K. These regions are likely to occupy at least 30% of the volume of a spiral arm near the midplane of the gaseous disk if the local supernova rate there is greater than 1.5 x 10 -7 Myr -1 pc -3 . Their presence in the interstellar medium is supported by observations of the soft X-ray background. The theory required to build a numerical simulation of interacting supernova remnants is developed. The hot cavities within a population of remnants will become connected for a variety of assumed conditions in the outer shells of old remnants. Extensive hot cavity regions or tunnels are built and enlarged by supernovae occurring in relatively dense gas which produce connections, but tunnels are kept hot primarily by supernovae occurring within the tunnels. The latter supernovae initiate fast shock waves which apparently reheat tunnels faster than they are destroyed by thermal conduction in a galactic magnetic field or by radiative cooling. However, the dispersal of these rejuvenating shocks over a wide volume is inhibited by motions of cooler interstellar gas in the interval between shocks. These motions disrupt the contiguity of the component cavities of a tunnel and may cause its death.The Monte Carlo simulations indicate that a quasi-equilibrium is reached within 10 7 years of the first supernova in a spiral arm. This equilibrium is characterized by a constant average filling fraction for cavities in the interstellar volume. Aspects of the equilibrium are discussed for a range of supernova rates. Two predictions of Cox and Smith are not confirmed within this range: critical growth of hot regions to encompass the entire medium, and the efficient quenching of a remnant's expansion by interaction with other cavities

  2. X-ray surface brightness of Kepler's supernova remnant

    International Nuclear Information System (INIS)

    White, R.L.; Long, K.S.

    1983-01-01

    We have observed Kepler's supernova remnant (SNR) with the imaging instruments on board the Einstein Observatory. The 0.15-4.5 keV flux incident on the Earth is 1.2 x 10 - 10 ergs cm - 2 s - 1 ; the flux corrected for interstellar absorption is 3.4 x 10 - 10 ergs cm - 2 s - 1 (L/sub x/ = 1.0 x 10 36 ergs s - 1 at D = 5 kpc) if the absorbing column density is N/sub H/ = 2.8 x 10 21 cm - 2 . The remnant is circular and shows a strong shell which is at least 5 times brighter in the north than in the south. The X-ray observations do not unambiguously determine whether the remnant is in the adiabatic or the free expansion phase. If the remnant is in the adiabatic phase, the density of the interstellar medium (ISM) ( 2 /sub e/>/sup 1/2/) surrounding Kepler's SNR must be about 5 cm - 3 . If the remnant is in the free expansion phase, where most of the emission arises from shock-heated ejecta, the ISM density must still be relatively high, n/sub i/> or approx. =0.1 cm - 3 . Even if the ISM is very inhomogeneous, with very many small, dense clouds, we show that the mean density of the ISM must be greater than approx.0.1 cm - 3 . In any case, the density of the x-ray emitting gas must be high ( 2 /sub e/>/sup 1/2/ > or approx. =10 cm - 3 ), and the temperature must be fairly low (T/sub e/ 7 K). The relatively high ISM density which is required is surprising in view of Kepler's distance above the galactic plane, approx.600 pc. Possibly the ISM around Kepler's SNR and around other type i SNRs is dominated by the mass lost from the presupernova star

  3. Viable Cancer Cells in the Remnant Stomach are a Potential Source of Peritoneal Metastasis after Curative Distal Gastrectomy for Gastric Cancer.

    Science.gov (United States)

    Murata, Satoshi; Yamamoto, Hiroshi; Yamaguchi, Tsuyoshi; Kaida, Sachiko; Ishida, Mitsuaki; Kodama, Hirokazu; Takebayashi, Katsushi; Shimizu, Tomoharu; Miyake, Toru; Tani, Tohru; Kushima, Ryoji; Tani, Masaji

    2016-09-01

    The mechanisms underlying peritoneal metastasis (PM) after curative gastrectomy for gastric cancer (GC) are not well elucidated. This study assessed whether viable cancer cells, including cancer stemlike cells (CSCs), were present in the remnant stomach immediately before gastrointestinal (GI) tract reconstruction because these could be a source of PM after gastrectomy. Saline fluid used for remnant stomach lumen irrigation before GI reconstruction was prospectively collected from 142 consecutive patients undergoing distal gastrectomy for GC and cytologically examined. Proliferative activity (Ki67 staining) and stemness (expression of the CSC surface markers CD44s or CD44v6) were evaluated in detected cancer cells. Viable cancer cells were detected in 33 (23.2 %) of the 142 remnant stomachs. These cells formed clusters and stained positively for Ki67, indicating proliferation. Cancer cells in remnant stomachs and surface cancer cells in primary GCs from 10 (30.3 %) of these 33 cases also stained positively for CD44s or CD44v6. In a multiple logistic regression analysis, advanced cancer (odds ratio [OR], 4.65; 95 % confidence interval [CI], 1.32-16.4; P = 0.017), tumor size of 40 mm or larger (OR, 3.78; 95 % CI, 1.12-12.8; P = 0.033), and histologic differentiation (OR, 3.10; 95 % CI, 1.30-7.40; P = 0.011) were associated independently with the presence of cancer cells in the remnant stomach. Viable, proliferative, and clustered cancer cells, including CSCs, were found in remnant gastric lumens immediately before GI reconstruction, indicating a possible cellular source of PM after curative gastrectomy for GC. Dissemination of gastric contents into the peritoneal cavity should be avoided during GI reconstruction.

  4. Changing rooster sperm membranes to facilitate cryopreservation

    Science.gov (United States)

    Cryopreservation damages rooster sperm membranes. Part of this damage is due to membrane transitioning from the fluid to the gel state as temperature is reduced. This damage may be prevented by increasing membrane fluidity at low temperatures by incorporating cholesterol or unsaturated lipids into t...

  5. Drug Clearance from Cerebrospinal Fluid Mediated by Organic Anion Transporters 1 (Slc22a6) and 3 (Slc22a8) at Arachnoid Membrane of Rats.

    Science.gov (United States)

    Zhang, Zhengyu; Tachikawa, Masanori; Uchida, Yasuo; Terasaki, Tetsuya

    2018-03-05

    Although arachnoid mater epithelial cells form the blood-arachnoid barrier (BAB), acting as a blood-CSF interface, it has been generally considered that the BAB is impermeable to water-soluble substances and plays a largely passive role. Here, we aimed to clarify the function of transporters at the BAB in regulating CSF clearance of water-soluble organic anion drugs based on quantitative targeted absolute proteomics (QTAP) and in vivo analyses. Protein expression levels of 61 molecules, including 19 ATP-binding-cassette (ABC) transporters and 32 solute-carrier (SLC) transporters, were measured in plasma membrane fraction of rat leptomeninges using QTAP. Thirty-three proteins were detected; others were under the quantification limits. Expression levels of multidrug resistance protein 1 (Mdr1a/P-gp/Abcb1a) and breast cancer resistance protein (Bcrp/Abcg2) were 16.6 and 3.27 fmol/μg protein (51.9- and 9.82-fold greater than in choroid plexus, respectively). Among those organic anion transporters detected only at leptomeninges, not choroid plexus, organic anion transporter 1 (oat1/Slc22a6) showed the greatest expression (2.73 fmol/μg protein). On the other hand, the protein expression level of oat3 at leptomeninges was 6.65 fmol/μg protein, and the difference from choroid plexus was within two-fold. To investigate oat1's role, we injected para-aminohippuric acid (PAH) with or without oat1 inhibitors into cisterna magna (to minimize the contribution of choroid plexus function) of rats. A bulk flow marker, FITC-inulin, was not taken up from CSF up to 15 min, whereas uptake clearance of PAH was 26.5 μL/min. PAH uptake was completely blocked by 3 mM cephalothin (inhibits both oat1 and oat3), while 17% of PAH uptake was inhibited by 0.2 mM cephalothin (selectively inhibits oat3). These results indicate that oat1 and oat3 at the BAB provide a distinct clearance pathway of organic anion drugs from CSF independently of choroid plexus.

  6. Insertable fluid flow passage bridgepiece and method

    Science.gov (United States)

    Jones, Daniel O.

    2000-01-01

    A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.

  7. Contribution of infrared observations to the study of supernovae remnants

    International Nuclear Information System (INIS)

    Douvion, Thomas

    2000-01-01

    This research thesis addresses the study of dust in young supernovae remnants observed in middle infrared, mainly by means of the ISOCAM instrument installed on the ISO satellite. The author first presents the supernovae physics and the studied young remnants, describes dusts and the main sites of formation and destruction, and outlines the difficulties and benefits of observations performed in the middle infrared. Then, the author reports acquired evidences related to the formation of dusts in supernovae, and the search for a millimetre emission by cold dust contained in regions which are not yet excited by the shock, in order to better assess the overall quantities created by supernovae. He reports the use of observations of dust and neon in Cassiopeia A to perform a diagnosis on the mixture of elements during the supernovae explosion [fr

  8. The population of supernova remnants in the Magellanic Clouds

    CERN Document Server

    Dennefeld, M

    1978-01-01

    The detection of SNRs in the Magellanic Clouds is reviewed with emphasis on its limits. A sample of SNRs is then used to derive the mean interval between SN explosions, tau . After the maximum constraints have been put on all the other parameters, the distribution of diameters of remnants with diameter less than 30 pc in the LMC is shown to agree well with theoretical predictions. In adopting a mean value of E/sub 0//n/sub 0/ (energy at explosion over surrounding density) of 5*10/sup 51/ ergs cm/sup 3/, the best value of tau is 300+or-100 years in good agreement with predictions from statistics of supernovae in external galaxies. The small number of remnants in the SMC prevents a similar approach being used with any statistical significance. (20 refs).

  9. Dynamics of supernova remnants in the Galactic centre.

    Science.gov (United States)

    Bortolas, E.; Mapelli, M.; Spera, M.

    The Galactic centre (GC) is a unique place to study the extreme dynamical processes occurring near a super-massive black hole (SMBH). Here we simulate a large set of binaries orbiting the SMBH while the primary member undergoes a supernova (SN) explosion, in order to study the impact of SN kicks on the orbits of stars and dark remnants in the GC. We find that SN explosions are efficient in scattering neutron stars and other light stars on new (mostly eccentric) orbits, while black holes (BHs) tend to retain memory of the orbit of their progenitor star. SN kicks are thus unable to eject BHs from the GC: a cusp of dark remnants may be lurking in the central parsec of our Galaxy.

  10. Intestinal obstruction caused by omphalomesenteric duct remnant: usefulness of laparoscopy.

    Science.gov (United States)

    Bueno Lledó, J; Serralta Serra, A; Planeéis Roig, M; Dobón Giménez, F; Ibáñez Palacín, F; Rodero Rodero, R

    2003-10-01

    The anomalies related to omphalomesenteric duct remnant constitute an uncommon cause of intestinal obstruction, of which Meckel"s diverticulum and its variants represent the most important clinical presentation. In most cases they are asymptomatic and usually affect young patients. When symptomatic, they usually present episodes of gastrointestinal bleeding or acute abdomen syndromes caused by strangulation of intestinal loops as a result of fibrous intraabdominal remnants or inflammation produced by the diverticulum. In most cases, the unexpected presence of these alterations makes intraoperative diagnosis necessary. Treatment is surgical and consists in exeresis of the diverticulum or the fibrous band causing the clinical picture. We report two cases of persistence of the vitelline duct resolved by laparoscopic approach.

  11. Confinement of the crab pulsar's wind by its supernova remnant

    International Nuclear Information System (INIS)

    Kennel, C.F.; Coroniti, F.V.

    1984-01-01

    We construct a steady state, spherically symmetric, magnetohydrodynamic model of the Crab nebual. A highly relativistic, positronic pulsar wind is terminated by a strong MHD shock that decelerates the flow and increases its pressure to match boundary conditions imposed by the recently discovered supernova remnant that surrounds the nebula. If the magnetic luminosity of the pulsar wind upsteam of the shock is about 0.3% of its particle luminosity, the pressure and velocity boundary conditions imposed by the remnant place the shock where we infer it to be; near the outer boundary of an underluminous region observed to surround the pulsar. It is necessary to include the weak magnetization of the wind to satisfy the boundary conditions and to calculate the nebular synchrotron radiation self-consistently

  12. The optical emission from the supernova remnant HB 3

    Science.gov (United States)

    Fesen, R. A.; Gull, T. R.

    1983-01-01

    The supernova remnant HB 3 was first detected as a radio source by Brown and Hazard (1953). On the basis of subsequent radio studies, it was concluded that the object was a supernova remnant (SNR). HB 3 is located at the far western edge of the H II region/molecular cloud complex W3-W4-W5 (IC 1795-1805-1848). However, a physical association of HB 3 with this complex is uncertain. In the present investigation, attention is called to the probability that HB 3 exhibits a more extensive optical emission structure than previously realized, and one which agrees well with both the position and morphology of the radio emission. It is found that narrow-passband optical images strongly suggest an almost complete optical emission shell for HB 3. Spectroscopic observations are, however, required to confirm that this emission is characteristic of a SNR.

  13. Computational fluid dynamics modeling and analysis of Pd-based membrane module for CO{sub 2} capture from H{sub 2}/CO{sub 2} binary gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong-Yoon; Park, Myung-June [Ajou University, Suwon (Korea, Republic of); Hwang, Kyung-Ran; Park, Jong-Soo [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2015-07-15

    A Pd-based membrane module for the capture of CO{sub 2} from a H{sub 2}/CO{sub 2} binary gas mixture was considered, and computational fluid dynamics modeling was used to predict the module performance. Detailed models of momentum and mass balances, including local flux as a function of local linear velocity, satisfactorily described CO{sub 2} fraction in a retentate tube when compared to the experimental data under various feed flow rates. By using the model, several cases having different geometries, including the location and diameter of feed tube and the number and location of the feed and retentate tubes, were considered. Among tested geometries, the case of two feed tubes with each offset by an angle, θ, of 45° from the center line, and a feed tube diameter of 2.45mm showed the increase of the feed flow rate up to 11.80% compared to the reference case while a CO{sub 2} fraction of 90% in the retentate, which was the criterion for effective CO{sub 2} capture in the present study, was guaranteed. This would result in a plausible reduction in capital expenditures for the CO{sub 2} capture process.

  14. Chandra Observations of Tycho's Supernova Remnant U. Hwang , R ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    runaway thermal instabilities in a white dwarf. It was observed for 50 ks with the superb 0.5 resolution mirror on the Chandra X-ray .... emission that comes from ejecta that have propagated to the forward shock. Such a spectrum, taken from a portion of the west rim of the remnant, is shown in the right panel of Fig. 2. The fitted ...

  15. Cosmic Ray and Tev Gamma Ray Generation by Quasar Remnants

    Science.gov (United States)

    Boldt, Elihu; Loewenstein, Michael; White, Nicholas E. (Technical Monitor)

    2000-01-01

    Results from new broadband (radio to X-ray) high-resolution imaging studies of the dormant quasar remnant cores of nearby giant elliptical galaxies are now shown to permit the harboring of compact dynamos capable of generating the highest energy cosmic ray particles and associated curvature radiation of TeV photons. Confirmation would imply a global inflow of interstellar gas all the way to the accretion powered supermassive black hole at the center of the host galaxy.

  16. Study of the photon remnant in resolved photoproduction at HERA

    International Nuclear Information System (INIS)

    Derrick, M.; Krakauer, D.; Magill, S.

    1995-01-01

    Photoproduction at HERA is studied in ep collisions, with the ZEUS detector, for γp centre-of-mass energies ranging from 130-270 GeV. A sample of events with two high-p T jets (p T >6 GeV, η T with respect to the beam axis is measured to be 2.1±0.2 GeV, which demonstrates substantial mean transverse momenta for the photon remnant. (orig.)

  17. Time evolution of gamma rays from supernova remnants

    Science.gov (United States)

    Gaggero, Daniele; Zandanel, Fabio; Cristofari, Pierre; Gabici, Stefano

    2018-04-01

    We present a systematic phenomenological study focused on the time evolution of the non-thermal radiation - from radio waves to gamma rays - emitted by typical supernova remnants via hadronic and leptonic mechanisms, for two classes of progenitors: thermonuclear and core-collapse. To this aim, we develop a numerical tool designed to model the evolution of the cosmic ray spectrum inside a supernova remnant, and compute the associated multi-wavelength emission. We demonstrate the potential of this tool in the context of future population studies based on large collection of high-energy gamma-ray data. We discuss and explore the relevant parameter space involved in the problem, and focus in particular on their impact on the maximum energy of accelerated particles, in order to study the effectiveness and duration of the PeVatron phase. We outline the crucial role of the ambient medium through which the shock propagates during the remnant evolution. In particular, we point out the role of dense clumps in creating a significant hardening in the hadronic gamma-ray spectrum.

  18. Search for Nonthermal X-Rays from Supernova Remnant Shells

    Science.gov (United States)

    Petre, R.; Keohane, J.; Hwang, U.; Allen, G.; Gotthelf, E.

    The demonstration by ASCA that the nonthermal X-ray emission from the rim of SN1006 is synchrotron emission from TeV electrons, produced in the same environment responsible for cosmic ray protons and nuclei (Koyama et al. 1995, Nature 378, 255), has stimulated a search for nonthermal X-rays from other remnants. Nonthermal emission has subsequently been found to arise in the shells of at least two other remnants, Cas A and IC 443. In Cas A, a hard tail is detected using ASCA, XTE, and OSSE to energies exceeding 100 keV; the shape of the spectrum rules out all mechanisms except synchrotron radiation. In IC 443, the previously known hard emission has been shown using ASCA to be isolated to a small region along the rim of the remnant, where the shock is interacting most strongly with a molecular cloud. Nonthermal X-ray emission is thought to arise here by enhanced cosmic ray production associated with the shock/cloud interaction (Keohane et al. 1997, ApJ in press). We describe the properties of the nonthermal emission in SN1006, Cas A, and IC 443, and discuss the status of our search for nonthermal emission associated with the shocks of other Galactic and LMC SNR's.

  19. CORRELATION OF SUPERNOVA REMNANT MASERS AND GAMMA-RAY SOURCES

    International Nuclear Information System (INIS)

    Hewitt, John W.; Yusef-Zadeh, Farhad; Wardle, Mark

    2009-01-01

    Supernova remnants (SNRs) interacting with molecular clouds are potentially exciting systems in which to detect evidence of cosmic ray acceleration. Prominent γ-ray emission is produced via the decay of neutral pions when cosmic rays encounter nearby dense clouds. In many of the SNRs coincident with γ-ray sources, the presence of OH (1720 MHz) masers is used to identify interaction with dense gas and to provide a kinematic distance to the system. In this Letter we use statistical tests to demonstrate that there is a correlation between these masers and a class of GeV- to TeV-energy γ-ray sources coincident with interacting remnants. For pion decay the γ-ray luminosity provides a direct estimate of the local cosmic ray density. We find the cosmic ray density is enhanced by one to two orders of magnitude over the local solar value, comparable to X-ray-induced ionization in these remnants. The inferred ionization rates are sufficient to explain non-equilibrium chemistry in the post-shock gas, where high columns of hydroxyl are observed.

  20. Current status in remnant gastric cancer after distal gastrectomy

    Science.gov (United States)

    Ohira, Masaichi; Toyokawa, Takahiro; Sakurai, Katsunobu; Kubo, Naoshi; Tanaka, Hiroaki; Muguruma, Kazuya; Yashiro, Masakazu; Onoda, Naoyoshi; Hirakawa, Kosei

    2016-01-01

    Remnant gastric cancer (RGC) and gastric stump cancer after distal gastrectomy (DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori (H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis. PMID:26937131

  1. Are young supernova remnants interacting with circumstellar gas

    International Nuclear Information System (INIS)

    Chevalier, R.A.

    1982-01-01

    The young remnants of galactic Type I supernovae (SN 1006, SN 1572, and SN 1604) appear to be interacting with moderately dense gas (n/sub O/> or =0.1 cm -3 ). If the gas in the ambient interstellar medium, the observations suggest that gas of this density is fairly pervasive. If the gas is circumstellar, there are important implications for the progenitors of Type I supernovae. A plausible density distribution for circumstellar gas is rhoinfinityr -2 . The expansion of a supernova into such a medium is examined and is compared with expansion into a uniform medium. The two cases can be distinguished on the basis of their density profiles and their rates of expansion. Currently available data factor the hypothesis of expansion in a uniform medium for all three Type I remnants; the evidence is the strongest for SN 1572 and the weakest for SN 1604. Further X-ray and radio observations of the galactic remnants and of extragalactic Type I supernovae should serve to test this hypothesis

  2. Modelling neutrino and gamma-ray fluxes in supernova remnants

    International Nuclear Information System (INIS)

    Ballet, J; Cassam-Chenai, G; Maurin, G; Naumann, C

    2008-01-01

    Supernova remnants (SNRs) are believed to accelerate charged particles by diffusive shock acceleration (DSA) and to produce the majority of galactic cosmic rays, at least up to the 'knee' at 3-10 15 electron volts. In the framework of a hydrodynamic self-similar simulation of the evolution of young supernova remnants, its interaction with the ambient matter as well as the microwave and infrared background is studied. The photon spectra resulting from synchrotron and inverse Compton emission as well as from hadronic processes are calculated, as are the accompanying neutrino fluxes. Applying this method to the particular case of the SNR RXJ-1713, 7-3946, we find that its TeV emission can in principle be explained by pion decay if the ambient density is assumed to grow with increasing distance from the centre. The neutrino flux associated with this hadronic model is of a magnitude that may be detectable by a cubic-kilometre sized deep-sea neutrino telescope in the northern hemisphere. In this poster, a description of the supernova remnant simulation is given together with the results concerning RXJ-1713.

  3. Current-Induced Membrane Discharge

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; van Soestbergen, M.; Mani, A.

    2012-01-01

    . Salt depletion leads to a large electric field resulting in a local pH shift within the membrane with the effect that the membrane discharges and loses its ion selectivity. Since salt co-ions, H+ ions, and OH- ions contribute to OLC, CIMD interferes with electrodialysis (salt counterion removal...... neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge'' (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length...

  4. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  5. Fouling resistant membrane spacers

    KAUST Repository

    Ghaffour, Noreddine

    2017-10-12

    Disclosed herein are spacers having baffle designs and perforations for efficiently and effectively separating one or more membrane layers a membrane filtration system. The spacer (504) includes a body (524) formed at least in part by baffles (520) that are interconnected, and the baffles define boundaries of openings or apertures (525) through a thickness direction of the body of the spacer. Alternatively or additionally, passages or perforations (526A, 526B) may be present in the spacer layer or baffles for fluid flow there through, with the passages and baffles having a numerous different shapes and sizes.

  6. Fluid Mechanics.

    Science.gov (United States)

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  7. Drying of supercritical carbon dioxide with membrane processes

    NARCIS (Netherlands)

    Lohaus, Theresa; Scholz, Marco; Koziara, Beata; Benes, Nieck Edwin; Wessling, Matthias

    2015-01-01

    In supercritical extraction processes regenerating the supercritical fluid represents the main cost constraint. Membrane technology has potential for cost efficient regeneration of water-loaded supercritical carbon dioxide. In this study we have designed membrane-based processes to dehydrate

  8. OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

    Science.gov (United States)

    2002-01-01

    This is a NASA Hubble Space Telescope image of the tattered debris of a star that exploded 3,000 years ago as a supernova. This supernova remnant, called N132D, lies 169,000 light-years away in the satellite galaxy, the Large Magellanic Cloud. A Hubble Wide Field Planetary Camera 2 image of the inner regions of the supernova remnant shows the complex collisions that take place as fast moving ejecta slam into cool, dense interstellar clouds. This level of detail in the expanding filaments could only be seen previously in much closer supernova remnants. Now, Hubble's capabilities extend the detailed study of supernovae out to the distance of a neighboring galaxy. Material thrown out from the interior of the exploded star at velocities of more than four million miles per hour (2,000 kilometers per second) plows into neighboring clouds to create luminescent shock fronts. The blue-green filaments in the image correspond to oxygen-rich gas ejected from the core of the star. The oxygen-rich filaments glow as they pass through a network of shock fronts reflected off dense interstellar clouds that surrounded the exploded star. These dense clouds, which appear as reddish filaments, also glow as the shock wave from the supernova crushes and heats the clouds. Supernova remnants provide a rare opportunity to observe directly the interiors of stars far more massive than our Sun. The precursor star to this remnant, which was located slightly below and left of center in the image, is estimated to have been 25 times the mass of our Sun. These stars 'cook' heavier elements through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations will be used to determine the exact

  9. Ten years of experience with third and fourth branchial remnants.

    Science.gov (United States)

    Liberman, Moishe; Kay, Saundra; Emil, Sherif; Flageole, Hélène; Nguyen, Luong T; Tewfik, Ted L; Oudjhane, Kamal; Laberge, Jean-Martin

    2002-05-01

    Third and fourth branchial remnants may result in cysts and abscesses that are in close contact with the thyroid gland. These anomalies are rare and often present diagnostic and therapeutic challenges. The charts of patients diagnosed with a branchial anomaly between July 1991 and July 2001 at the Montreal Children's Hospital were reviewed. All cases of third and fourth branchial remnants or pyriform sinus fistulae were identified. Clinical presentation, imaging, treatment, and outcome were recorded. Eight patients with a third or fourth branchial anomaly were identified and ranged in age from birth to 13 years. All anomalies were left sided. Presenting symptoms consisted of an asymptomatic cervical mass (n = 1), an infected mass (n = 5), neonatal respiratory distress (n = 1), and 1 incidental cyst found on magnetic resonance imaging. Ultrasonography was useful in suggesting the diagnosis in 7 cases. Barium swallow was performed in 3 patients with 2 positive results. Pharyngoscopy results showed the internal opening in 2 of 7 patients. A portion of the thyroid gland was resected in 6 patients. One patient has not yet undergone a definitive procedure. There was 1 recurrence in a patient whose pathology did not confirm a branchial remnant. The diagnosis and management of pyriform sinus anomalies are challenging. Ultrasound scan, computed tomography scan, barium swallow, and pharyngoscopy are all useful. The portion of thyroid involved in the fistula must be excised en bloc with the inflammatory mass, and the tract should be ligated at the level of the pharynx to minimize recurrence. Copyright 2002, Elsevier Science (USA). All rights reserved.

  10. Remarks on Remnants by Fermions’ Tunnelling from Black Strings

    Directory of Open Access Journals (Sweden)

    Deyou Chen

    2014-01-01

    Full Text Available Hawking’s calculation is unable to predict the final stage of the black hole evaporation. When effects of quantum gravity are taken into account, there is a minimal observable length. In this paper, we investigate fermions’ tunnelling from the charged and rotating black strings. With the influence of the generalized uncertainty principle, the Hawking temperatures are not only determined by the rings, but also affected by the quantum numbers of the emitted fermions. Quantum gravity corrections slow down the increases of the temperatures, which naturally leads to remnants left in the evaporation.

  11. Radio and X-ray emission from newly born remnants

    International Nuclear Information System (INIS)

    Salvati, M.

    1983-01-01

    Radio and X-ray observations of SN 1979c and SN 1980k offer a unique opportunity of monitoring the transition from supernovae to remnants. By means of the two-frequency radio light curves, the hypothesis that these objects are surrounded by circumstellar matter, originated in a presupernova wind, is tested, and the relevant parameters are derived. Then the absorption-corrected light curves are used to test the various proposed models. SN 1980k appears to be powered by a canonical shock, while SN 1979c is a good plerion candidate. An optical pulsar could still be detected at its location. (Auth.)

  12. Radio and X-ray emission from supernova remnants

    International Nuclear Information System (INIS)

    Asvarova, A.I.; Novruzova, H.I.; Ahmedova, S.I.

    2010-01-01

    In this paper it was studied the statistical correlation between radio and X-ray emissions from shell-type supernova remnants (SNR). The primary aim of this study is to test the model of radio emission of shell-type SNRs presented by one of the authors. Based on this model of radio emission, by using the Monte Carlo techniques we have simulated statistical relations radio - X-ray luminosities (not surface brightnesses) which then were compared with the observations. X-ray emission is assumed to be thermal. To have a uniform statistical material it was used observational data on the SNRs in Magellanic Clouds

  13. A 3D View of a Supernova Remnant

    Science.gov (United States)

    Kohler, Susanna

    2017-06-01

    The outlined regions mark the 57 knots in Tycho selected by the authors for velocity measurements. Magenta regions have redshifted line-of-sight velocities (moving away from us); cyan regions have blueshifted light-of-sight velocities (moving toward us). [Williams et al. 2017]The Tycho supernova remnant was first observed in the year 1572. Nearly 450 years later, astronomers have now used X-ray observations of Tycho to build the first-ever 3D map of a Type Ia supernova remnant.Signs of ExplosionsSupernova remnants are spectacular structures formed by the ejecta of stellar explosions as they expand outwards into the surrounding interstellar medium.One peculiarity of these remnants is that they often exhibit asymmetries in their appearance and motion. Is this because the ejecta are expanding into a nonuniform interstellar medium? Or was the explosion itself asymmetric? The best way we can explore this question is with detailed observations of the remnants.Histograms of the velocity in distribution of the knots in the X (green), Y (blue) and Z (red) directions (+Z is away from the observer). They show no evidence for asymmetric expansion of the knots. [Williams et al. 2017]Enter TychoTo this end, a team of scientists led by Brian Williams (Space Telescope Science Institute and NASA Goddard SFC) has worked to map out the 3D velocities of the ejecta in the Tycho supernova remnant. Tycho is a Type Ia supernova thought to be caused by the thermonuclear explosion of a white dwarf in a binary system that was destabilized by mass transfer from its companion.After 450 years of expansion, the remnant now has the morphological appearance of a roughly circular cloud of clumpy ejecta. The forward shock wave from the supernova, however, is known to have twice the velocity on one side of the shell as on the other.To better understand this asymmetry, Williams and collaborators selected a total of 57 knots in Tychos ejecta, spread out around the remnant. They then used 12 years of

  14. Composite perfluorohydrocarbon membranes, their preparation and use

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yong; Bikson, Benjamin

    2017-04-04

    Composite porous hydrophobic membranes are prepared by forming a perfluorohydrocarbon layer on the surface of a preformed porous polymeric substrate. The substrate can be formed from poly (aryl ether ketone) and a perfluorohydrocarbon layer can be chemically grafted to the surface of the substrate. The membranes can be utilized for a broad range of fluid separations, such as microfiltration, nanofiltration, ultrafiltration as membrane contactors for membrane distillation and for degassing and dewatering of fluids. The membranes can further contain a dense ultra-thin perfluorohydrocarbon layer superimposed on the porous poly (aryl ether ketone) substrate and can be utilized as membrane contactors or as gas separation. membranes for natural gas treatment and gas dehydration.

  15. Fluids engineering

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  16. Nonperturbative Renormalization Group Approach to Polymerized Membranes

    Science.gov (United States)

    Essafi, Karim; Kownacki, Jean-Philippe; Mouhanna, Dominique

    2014-03-01

    Membranes or membrane-like materials play an important role in many fields ranging from biology to physics. These systems form a very rich domain in statistical physics. The interplay between geometry and thermal fluctuations lead to exciting phases such flat, tubular and disordered flat phases. Roughly speaking, membranes can be divided into two group: fluid membranes in which the molecules are free to diffuse and thus no shear modulus. On the other hand, in polymerized membranes the connectivity is fixed which leads to elastic forces. This difference between fluid and polymerized membranes leads to a difference in their critical behaviour. For instance, fluid membranes are always crumpled, whereas polymerized membranes exhibit a phase transition between a crumpled phase and a flat phase. In this talk, I will focus only on polymerized phantom, i.e. non-self-avoiding, membranes. The critical behaviour of both isotropic and anisotropic polymerized membranes are studied using a nonperturbative renormalization group approach (NPRG). This allows for the investigation of the phase transitions and the low temperature flat phase in any internal dimension D and embedding d. Interestingly, graphene behaves just as a polymerized membrane in its flat phase.

  17. Remnant trees affect species composition but not structure of tropical second-growth forest.

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

  18. Amniotic fluid embolism

    Directory of Open Access Journals (Sweden)

    Kiranpreet Kaur

    2016-01-01

    Full Text Available Amniotic fluid embolism (AFE is one of the catastrophic complications of pregnancy in which amniotic fluid, fetal cells, hair, or other debris enters into the maternal pulmonary circulation, causing cardiovascular collapse. Etiology largely remains unknown, but may occur in healthy women during labour, during cesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post-delivery. It can also occur during abortion, after abdominal trauma, and during amnio-infusion. The pathophysiology of AFE is not completely understood. Possible historical cause is that any breach of the barrier between maternal blood and amniotic fluid forces the entry of amniotic fluid into the systemic circulation and results in a physical obstruction of the pulmonary circulation. The presenting signs and symptoms of AFE involve many organ systems. Clinical signs and symptoms are acute dyspnea, cough, hypotension, cyanosis, fetal bradycardia, encephalopathy, acute pulmonary hypertension, coagulopathy etc. Besides basic investigations lung scan, serum tryptase levels, serum levels of C3 and C4 complements, zinc coproporphyrin, serum sialyl Tn etc are helpful in establishing the diagnosis. Treatment is mainly supportive, but exchange transfusion, extracorporeal membrane oxygenation, and uterine artery embolization have been tried from time to time. The maternal prognosis after amniotic fluid embolism is very poor though infant survival rate is around 70%.

  19. A modified theoretical Σ − D relation for supernova remnants: I. The case of constant temperature within the supernova remnant

    Directory of Open Access Journals (Sweden)

    Urošević Dejan V.

    2003-01-01

    Full Text Available We present a modification of the theoretical Σ − D relation for supernova remnants (SNRs in the adiabatic expansion phase. This modification is based on the convolution of the relation first derived by Shklovsky with the Σ − D relation derived in this paper for thermal bremsstrahlung radiation from the ionized gas cloud. We adopt McKee & Ostriker’s model for the components of the interstellar medium as part of our derivation. The modified Shklovsky theory agrees well with empirical results. Kesteven’s modified theoretical relation gives the best agreement with the updated Galactic empirical Σ − D relation.

  20. Improved optical spectrophotometry of supernova remnants in M33

    Science.gov (United States)

    Blair, W. P.; Kirshner, R. P.

    1985-01-01

    Optical spectra of SNRs in M33 have been used to investigate abundance gradients and SNR evolution in this galaxy. Abundances of O, N, and S are derived from the spectra using new shock models by Dopita et al. (1984). The results for N and S show abundance gradients similar to those in NGC 300 and the Galaxy. The O abundances may be affected by possible contamination from H II regions and low-velocity shocks. Electron densities derived from the forbidden S II 6717 A/6731 A line ratio are used with a pressure equilibrium argument to estimate the initial explosion energy for each SNR. Evolutionary models for the remnants are investigated, and the distribution of the number of remnants with diameter is found to be consistent with free expansion of the SNRs to diameters of about 26 pc. The results may also be consistent with Sedov evolution if the ranges of initial supernova energies and surrounding interstellar medium densities are large enough.

  1. DESTRUCTION OF INTERSTELLAR DUST IN EVOLVING SUPERNOVA REMNANT SHOCK WAVES

    International Nuclear Information System (INIS)

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-01-01

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however, that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al., we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities ≳200 km s −1 for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of ∼2 compared to those of Jones et al., who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of ∼3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of ∼2–3 Gyr. These increases, while not able to resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step toward understanding the origin and evolution of dust in the ISM

  2. RADIO POLARIMETRY SIGNATURES OF STRONG MAGNETIC TURBULENCE IN SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Stroman, Wendy; Pohl, Martin

    2009-01-01

    We discuss the emission and transport of polarized radio-band synchrotron radiation near the forward shocks of young shell-type supernova remnants, for which X-ray data indicate a strong amplification of turbulent magnetic field. Modeling the magnetic turbulence through the superposition of waves, we calculate the degree of polarization and the magnetic polarization direction which is at 90 deg. to the conventional electric polarization direction. We find that isotropic strong turbulence will produce weakly polarized radio emission even in the absence of internal Faraday rotation. If anisotropy is imposed on the magnetic-field structure, the degree of polarization can be significantly increased, provided internal Faraday rotation is inefficient. Both for shock compression and a mixture with a homogeneous field, the increase in polarization degree goes along with a fairly precise alignment of the magnetic-polarization angle with the direction of the dominant magnetic-field component, implying tangential magnetic polarization at the rims in the case of shock compression. We compare our model with high-resolution radio polarimetry data of Tycho's remnant. Using the absence of internal Faraday rotation we find a soft limit for the amplitude of magnetic turbulence, δB ∼ 0 . An alternative viable scenario involves anisotropic turbulence with stronger amplitudes in the radial direction, as was observed in recent Magnetohydrodynamics simulations of shocks propagating through a medium with significant density fluctuations.

  3. [Management of urachal remnants in children: Is surgical excision mandatory?].

    Science.gov (United States)

    Heuga, B; Mouttalib, S; Bouali, O; Juricic, M; Galinier, P; Abbo, O

    2015-09-01

    The classical management of urachal remants consists in surgical resection, in order to prevent infections and long term malignancies. However, some reports have recently spread a wait and see management. The aim of our study was to report the results of the surgical management in our center. We conducted a retrospective, monocentric review of all patients managed for urachal remnants from January 2005 to December 2014. Thirty-five patients have been operated during the study period (18 girls and 17 boys). Mean age at surgery was 4,9±4,4 years old. Twenty-seven patients were referred due to symptoms whereas 8 were discovered incidentally (4 by ultrasound scan and 4 during laparoscopy). Among them, 10 were urachal cysts, 15 were urachus sinusa and 10 were patent urachus. Thirty were operated using an open approach and 5 using a laparoscopic approach. Mean length of stay was 3,8±1,7days (1-10) with a mean duration of bladder drainage of 2,5±1 days. No major complications occurred. No abnormal tissue was discovered at the histological analysis. Presentation of urachal remnants is variable but surgical outcomes remain excellent in our experience. When symptoms occur, the surgical decision is easy, but when the diagnosis is incidental, the decision is much more complicated. Official guidelines could ease the decision process and the management of urachal anomalies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. FERMI LARGE AREA TELESCOPE OBSERVATION OF SUPERNOVA REMNANT S147

    Energy Technology Data Exchange (ETDEWEB)

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; Tajima, H.; Bechtol, K.; Funk, S.; Lande, J. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Hanabata, Y. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Lemoine-Goumard, M. [Universite Bordeaux 1, CNRS/IN2p3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, 33175 Gradignan (France); Takahashi, T., E-mail: katsuta@slac.stanford.edu, E-mail: uchiyama@slac.stanford.edu [Institute of Space and Astronautical Science, Japanese Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2012-06-20

    We present an analysis of gamma-ray data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope in the region around supernova remnant (SNR) S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 Multiplication-Sign 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with the prominent H{alpha} filaments of SNR S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. The reacceleration of the pre-existing cosmic rays and subsequent adiabatic compression in the filaments is sufficient to provide the energy density required of high-energy protons.

  5. Population III Stars and Remnants in High-redshift Galaxies

    Science.gov (United States)

    Xu, Hao; Wise, John H.; Norman, Michael L.

    2013-08-01

    Recent simulations of Population III star formation have suggested that some fraction form in binary systems, in addition to having a characteristic mass of tens of solar masses. The deaths of metal-free stars result in the initial chemical enrichment of the universe and the production of the first stellar-mass black holes. Here we present a cosmological adaptive mesh refinement simulation of an overdense region that forms a few 109 M ⊙ dark matter halos and over 13,000 Population III stars by redshift 15. We find that most halos do not form Population III stars until they reach M vir ~ 107 M ⊙ because this biased region is quickly enriched from both Population III and galaxies, which also produce high levels of ultraviolet radiation that suppress H2 formation. Nevertheless, Population III stars continue to form, albeit in more massive halos, at a rate of ~10-4 M ⊙ yr-1 Mpc-3 at redshift 15. The most massive starless halo has a mass of 7 × 107 M ⊙, which could host massive black hole formation through the direct gaseous collapse scenario. We show that the multiplicity of the Population III remnants grows with halo mass above 108 M ⊙, culminating in 50 remnants located in 109 M ⊙ halos on average. This has implications that high-mass X-ray binaries and intermediate-mass black holes that originate from metal-free stars may be abundant in high-redshift galaxies.

  6. Dust in Supernovae and Supernova Remnants II: Processing and Survival

    Science.gov (United States)

    Micelotta, E. R.; Matsuura, M.; Sarangi, A.

    2018-03-01

    Observations have recently shown that supernovae are efficient dust factories, as predicted for a long time by theoretical models. The rapid evolution of their stellar progenitors combined with their efficiency in precipitating refractory elements from the gas phase into dust grains make supernovae the major potential suppliers of dust in the early Universe, where more conventional sources like Asymptotic Giant Branch (AGB) stars did not have time to evolve. However, dust yields inferred from observations of young supernovae or derived from models do not reflect the net amount of supernova-condensed dust able to be expelled from the remnants and reach the interstellar medium. The cavity where the dust is formed and initially resides is crossed by the high velocity reverse shock which is generated by the pressure of the circumstellar material shocked by the expanding supernova blast wave. Depending on grain composition and initial size, processing by the reverse shock may lead to substantial dust erosion and even complete destruction. The goal of this review is to present the state of the art about processing and survival of dust inside supernova remnants, in terms of theoretical modelling and comparison to observations.

  7. A blowout numerical model for the supernova remnant G352.7-0.1

    OpenAIRE

    Toledo Roy, J. C.; Velazquez, P. F.; Esquivel, A.; Giacani, Elsa Beatriz

    2017-01-01

    We present 3D hydrodynamical simulations of the Galactic supernova remnant G352.7−0.1. This remnant is peculiar for having a shell-like inner ring structure and an outer arc in radio observations. In our model, the supernova explosion producing the remnant occurs inside and near the border of a spherical cloud with a density higher than that of the surrounding interstellar medium. A blowout is produced when the remnant reaches the border of the cloud. We have then used the results of our hydr...

  8. Pancreatic Cancer Arising From the Remnant Pancreas: Is It a Local Recurrence or New Primary Lesion?

    Science.gov (United States)

    Hashimoto, Daisuke; Chikamoto, Akira; Masuda, Toshiro; Nakagawa, Shigeki; Imai, Katsunori; Yamashita, Yo-Ichi; Reber, Howard A; Baba, Hideo

    2017-10-01

    Local recurrence of pancreatic cancer (PC) can occur in the pancreatic remnant. In addition, new primary PC can develop in the remnant. There are limited data available regarding this so-called remnant PC. The aim of this review was to describe the characteristics and therapeutic strategy regarding remnant PC. A literature search was performed using Medline published in English according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The incidence of remnant PC has been reported to be 3% to 5%. It is difficult to distinguish local recurrence from new primary PC. Genetic diagnosis such as Kirsten rat sarcoma viral oncogene homolog mutation may resolve this problem. For patients with remnant PC, repeated pancreatectomy can be performed. Residual total pancreatectomy is the most common procedure. Recent studies have described the safety of the operation because of recent surgical progress and perioperative care. The patients with remnant PC without distant metastasis have shown good long-term outcomes, especially those who underwent repeated pancreatectomy. Adjuvant chemotherapy may contribute to longer survival. In conclusion, this review found that both local recurrence and new primary PC can develop in the pancreatic remnant. Repeated pancreatectomy for the remnant PC is a feasible procedure and can prolong patient survival.

  9. Buffer fluid

    Energy Technology Data Exchange (ETDEWEB)

    Mirzadzhanzade, A Kh; Dedusanko, G Ya; Dinaburg, L S; Markov, Yu M; Rasizade, Ya N; Rozov, V N; Sherstnev, N M

    1979-08-30

    A drilling fluid is suggested for separating the drilling and plugging fluids which contains as the base increased solution of polyacrylamide and additive. In order to increase the viscoelastic properties of the liquid with simultaneous decrease in the periods of its fabrication, the solution contains as an additive dry bentonite clay. In cases of the use of a buffer fluid under conditions of negative temperatures, it is necessary to add to it table salt or ethylene glycol.

  10. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  11. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    OpenAIRE

    Maria URSACHI (BOLOTA); Emil ANTON; Sorana Caterina ANTON

    2016-01-01

    The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amn...

  12. Schroedinger fluid

    International Nuclear Information System (INIS)

    Kan, K.K.

    1983-01-01

    The relationship of nuclear internal flow and collective inertia, the difference of this flow from that of a classical fluid, and the approach of this flow to rigid flow in independent-particle model rotation are elucidated by reviewing the theory of Schroedinger fluid and its implications for collective vibration and rotation. (author)

  13. NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C.

    2012-01-01

    The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, γ, and three distinct values are taken for the cavity (γ 1 ), the shell (γ 2 ), and the ISM (γ 3 ) with the condition γ 2 1 , γ 3 . This low value of γ 2 accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a

  14. Physics of biological membranes

    Science.gov (United States)

    Mouritsen, Ole G.

    The biological membrane is a complex system consisting of an aqueous biomolecular planar aggregate of predominantly lipid and protein molecules. At physiological temperatures, the membrane may be considered a thin (˜50Å) slab of anisotropic fluid characterized by a high lateral mobility of the various molecular components. A substantial fraction of biological activity takes place in association with membranes. As a very lively piece of condensed matter, the biological membrane is a challenging research topic for both the experimental and theoretical physicists who are facing a number of fundamental physical problems including molecular self-organization, macromolecular structure and dynamics, inter-macromolecular interactions, structure-function relationships, transport of energy and matter, and interfacial forces. This paper will present a brief review of recent theoretical and experimental progress on such problems, with special emphasis on lipid bilayer structure and dynamics, lipid phase transitions, lipid-protein and lipid-cholesterol interactions, intermembrane forces, and the physical constraints imposed on biomembrane function and evolution. The paper advocates the dual point of view that there are a number of interesting physics problems in membranology and, at the same time, that the physical properties of biomembranes are important regulators of membrane function.

  15. Fluid control structures in microfluidic devices

    Science.gov (United States)

    Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

    2017-05-09

    Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

  16. Detection of explosive remnants of war by neutron thermalisation

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, F.D., E-mail: frank.brooks@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa); Drosg, M. [Faculty of Physics, University of Vienna, Wien A-1090 (Austria); Smit, F.D.; Wikner, C. [iThemba Laboratory for Accelerator-Based Sciences, Somerset West 7129 (South Africa)

    2012-01-15

    The HYDAD-D landmine detector () has been modified and field-tested for 17 months in a variety of soil conditions. Test objects containing about the same mass of hydrogen (20 g) as small explosive remnants of war, such as antipersonnel landmines, were detected with efficiency 100% when buried at cover depths up to 10 cm. The false alarm rate under the same conditions was 9%. Plots of detection efficiency versus false alarm rate are presented. - Highlights: Black-Right-Pointing-Pointer A new version of the HYDAD-D antipersonnel landmine detector is described. Black-Right-Pointing-Pointer Field tests were carried out for 17 months under different conditions. Black-Right-Pointing-Pointer Dummy antipersonnel mines were detected with 100% efficiency at cover depths up to 10 cm. Black-Right-Pointing-Pointer Results are presented as plots of landmine detection efficiency versus false alarm rate.

  17. Compact binary merger and kilonova: outflows from remnant disc

    Science.gov (United States)

    Yi, Tuan; Gu, Wei-Min; Liu, Tong; Kumar, Rajiv; Mu, Hui-Jun; Song, Cui-Ying

    2018-05-01

    Outflows launched from a remnant disc of compact binary merger may have essential contribution to the kilonova emission. Numerical calculations are conducted in this work to study the structure of accretion flows and outflows. By the incorporation of limited-energy advection in the hyper-accretion discs, outflows occur naturally from accretion flows due to imbalance between the viscous heating and the sum of the advective and radiative cooling. Following this spirit, we revisit the properties of the merger outflow ejecta. Our results show that around 10-3 ˜ 10-1 M⊙ of the disc mass can be launched as powerful outflows. The amount of unbound mass varies with the disc mass and the viscosity. The outflow-contributed peak luminosity is around 1040 ˜ 1041 erg s-1. Such a scenario can account for the observed kilonovae associated with short gamma-ray bursts, including the recent event AT2017gfo (GW170817).

  18. Shocked molecular hydrogen in the supernova remnant IC 443

    International Nuclear Information System (INIS)

    Burton, M.G.; Brand, P.W.J.L.; Webster, A.S.

    1988-01-01

    Emission from the υ = 1-0 S(1) line of molecular hydrogen has been mapped over a section of the supernova remnant IC 443. The emission originates in a sinuous ridge where the expanding shell of the SNR is interacting with a molecular cloud. The relative intensities of the 1-0 S(1), 1-0 S(0) and 2-1 S(1) lines at 2.1-2.2 μm were measured and found to be characteristic of shock-excitation of the gas. The ridge shows bright spots which are possibly density enhancements in the molecular cloud. The total luminosity of the molecular hydrogen lines in the mapped region is estimated to be about 1000 times the solar luminosity, making IC 443 one of the most luminous galactic molecular hydrogen sources yet detected. (author)

  19. New selection effect of statistical investigations of supernova remnants

    International Nuclear Information System (INIS)

    Allakhverdiev, A.O.; Gusejnov, O.Kh.; Kasumov, F.K.

    1986-01-01

    The influence of H2 regions on the parameters of Supernova remnants (SNR) is investigated. It has been shown that the projection of such regions on the SNRs leads to local changes of morphological structure of young shell-type SNRs and considerable distortions of integral parameters of evolved shell-type SNRs (with D > 10 pc) and plerions, up to their complete undetectability on the background of classical and gigantic H2 regions. A new selection effect, in fact, arises from these factors connected with additional limitations made by the real structure of the interstellar medium on the statistical investigations of SNRs. The influence of this effect on the statistical completeness of objects has been estimated

  20. New selection effect in statistical investigations of supernova remnants

    Science.gov (United States)

    Allakhverdiev, A. O.; Guseinov, O. Kh.; Kasumov, F. K.

    1986-01-01

    The influence of H II regions on the parameters of supernova remnants (SNR) is investigated. It has been shown that the projection of such regions on the SNRs leads to: a) local changes of morphological structure of young shell-type SNRs and b) considerable distortions of integral parameters of evolved shell-type SNRs (with D > 10 pc) and plerions, up to their complete undetectability on the background of classical and gigantic H II regions. A new selection effect, in fact, arises from these factors connected with additional limitations made by the real structure of the interstellar medium on the statistical investigations of SNRs. The influence of this effect on the statistical completeness of objects has been estimated.

  1. Grain Destruction in a Supernova Remnant Shock Wave

    Science.gov (United States)

    Raymond, John C.; Ghavamian, Parviz; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Gaetz, Terrance J.; Sankrit, Ravi

    2014-01-01

    Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants, gradually enriching the gas phase with refractory elements. We have measured emission in C IV (lambda)1550 from C atoms sputtered from dust in the gas behind a non-radiative shock wave in the northern Cygnus Loop. Overall, the intensity observed behind the shock agrees approximately with predictions from model calculations that match the Spitzer 24 micron and the X-ray intensity profiles. Thus these observations confirm the overall picture of dust destruction in SNR shocks and the sputtering rates used in models. However, there is a discrepancy in that the CIV intensity 10'' behind the shock is too high compared to the intensities at the shock and 25'' behind it. Variations in the density, hydrogen neutral fraction and the dust properties over parsec scales in the pre- shock medium limit our ability to test dust destruction models in detail.

  2. Approximate supernova remnant dynamics with cosmic ray production

    International Nuclear Information System (INIS)

    Voelk, H.J.; Drury, L.O.; Dorfi, E.A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probable sources of cosmic rays. Recent shock acceleration models treating the cosmic rays (CR's) as test particles nb a prescribed supernova remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the interstellar medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation

  3. Approximate supernova remnant dynamics with cosmic ray production

    Science.gov (United States)

    Voelk, H. J.; Drury, L. O.; Dorfi, E. A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probably sources of Cosmic Rays. Recent shock acceleration models treating the Cosmic Rays (CR's) as test particles nb a prescribed Supernova Remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the Interstellar Medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation.

  4. Diffuse remnants of supernova explosions of moving massive stars

    Science.gov (United States)

    Gvaramadze, V. V.

    The modification of the ambient interstellar medium by the wind of massive stars (the progenitors of most of supernovae) results in that the structure and evolution of diffuse supernova remnants (SNRs) significantly deviate from those derived from standard models of SNRs based of the Sedov-Taylor solution. The stellar proper motion and the regular interstellar magnetic field affect the symmetry of the processed medium and cause the SNR to be non-spherically-symmetric. We show that taking into account these effects allows us to explain the diverse morphologies of the known SNRs (the particular attention is paid to the elongated axisymmetric SNRs and the SNRs consisting of two partially overlapping shells) and to infer the ``true" supernova explosion sites in some peculiar SNRs (therefore to search for new neutron stars associated with them).

  5. Remnants of black rings from gravity’s rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag [Center for Fundamental Physics, Zewail City of Science and Technology,6th of October City, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University,Benha 13518 (Egypt); Faizal, Mir [Department of Physics and Astronomy, University of Waterloo,Waterloo, Ontario, N2L 3G1 (Canada); Khalil, Mohammed M. [Department of Electrical Engineering, Alexandria University,El-Horreya Rd., Alexandria 12544 (Egypt)

    2014-12-29

    In this paper, we investigate a spinning black ring and a charged black ring in the context of gravity’s rainbow. By incorporating rainbow functions proposed by Amelino-Camelia, et al. in http://dx.doi.org/10.1142/S0217751X97000566 http://dx.doi.org/10.12942/lrr-2013-5 in the metric of the black rings, a considerable modification happens to their thermodynamical properties. We calculate corrections to the temperature, entropy and heat capacity of the black rings. These calculations demonstrate that the behavior of Hawking radiation changes considerably near the Planck scale in gravity’s rainbow, where it is shown that black rings do not evaporate completely and a remnant is left as the black rings evaporate down to Planck scale.

  6. Differentiation between healthy thyroid remnants and tumor tissue after radioiodine therapy in patients with differentiated thyroid carcinoma using in-vitro phosphorus-31 magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Moka, D.; Dietlein, M.; Schicha, H.; Raffelt, K.; Hahn, J.

    2002-01-01

    Full text: In many tumors, tumor growth and spread is triggered by changes in cell membrane metabolism, which can lead to systemic alterations in levels of phospholipids. The aim of this study was to differentiate between healthy remnants of thyroid tissue and residual/recurrent tumor tissue or metastases in patients with thyroid carcinoma by measurement of plasma levels of various phospholipids. Phospholipid concentrations was measured by in-vitro phosphorus-31-magnetic resonance spectroscopy ( 31 P-MRS) in blood samples from 30 patients with thyroid cancer, who had been rendered hypothyroid in preparation for diagnostic/therapeutic administration of iodine-131. All patients were already thyroidectomized. 131 I-whole-body scintigraphy and measurements of thyroglobulin values in a 2-year-follow-up were used to distinguish between patients in remission, patients with only healthy thyroid remnants and patients with cancerous thyroid tissue and/or metastases. Significantly lower blood plasma levels of systemic sphingomyelin (0.33±0.06 vs. 0.46±0.03 (controls) mmol/l; p 31 P-MRS can be used to differentiate between the presence of tumor tissue, healthy remnants of thyroid tissue not requiring further treatment and remission in patients with thyroid cancer. In future, therefore, plasma 31 P-MRS could be developed as an additional diagnostic tool for the follow-up of differentiated thyroid cancer. (author)

  7. Supernova models with slow energy pumping and galactic supernova remnants

    International Nuclear Information System (INIS)

    Utrobin, V.P.

    1978-01-01

    The study of supernova (SN) models with slow energy pumping is continued. At maximum luminosity the main characteristics of a SN are shown to be independent of the initial structure of the model. However, they depend on the mass Msub(e) of the envelope, and on the intensity of energy pumping Lsub(epsilon), with an increase of Msub(e) leading qualitatively to the same changes in the SN parameters as a decrease in Lsub(epsilon). A simple relationship connecting the important SN parameters is obtained. From the inflection of the color index B-V curve, the possibility of deriving the characteristic time of energy pumping with intensity Lsub(epsilon) approximately 10 44 erg s -1 is pointed out. The comparison of the extragalactic type I SN observations with the results of calculations leads to the estimate of Msub(e) approximately 0.3-0.7 solar masses. An investigation of the galactic type I SN remnants is carried out. The estimate of Msub(e) approximately 0.2-0.3 solar masses is obtained for the remnants of supernovae SN 1006, SN 1572, and SN 1604. It completely fits the results for the extragalactic type I SNs. The total initial mass of SN 1604 presupernova was shown to be at least about 7 solar masses. It was established that the Crab nebula resulted from the outburst of a peculiar SN. The unique properties of such SNs, including SN 1054, are due to the low intensity of energy pumping (Lsub(epsilon) approximately 10 42 erg s -1 ). The mass of the envelope of the Crab nebula is evaluated to be Msub(e) approximately 0.7 solar masses. (Auth.)

  8. Supernova remnant W49B and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.; Tian, W. W.; Zuo, P., E-mail: zhuhui@bao.ac.cn, E-mail: tww@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-10-01

    We study gamma-ray supernova remnant (SNR) W49B and its environment using recent radio and infrared data. Spitzer Infrared Spectrograph low resolution data of W49B shows shocked excitation lines of H{sub 2} (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H{sub 2} gas is composed of two components with temperatures of ∼260 K and ∼1060 K, respectively. Various spectral lines from atomic and ionic particles are detected toward W49B. We suggest that the ionic phase has an electron density of ∼500 cm{sup –3} and a temperature of ∼10{sup 4} K by the spectral line diagnoses. The mid- and far-infrared data from MSX, Spitzer, and Herschel reveal a 151 ± 20 K hot dust component with a mass of 7.5 ± 6.6 × 10{sup –4} M {sub ☉} and a 45 ± 4 K warm dust component with a mass of 6.4 ± 3.2 M {sub ☉}. The hot dust is likely from materials swept up by the shock of W49B. The warm dust may possibly originate from the evaporation of clouds interacting with W49B. We build the H I absorption spectra of W49B and four nearby H II regions (W49A, G42.90+0.58, G42.43-0.26, and G43.19-0.53) and study the relation between W49B and the surrounding molecular clouds by employing the 2.12 μm infrared and CO data. We therefore obtain a kinematic distance of ∼10 kpc for W49B and suggest that the remnant is likely associated with the CO cloud at about 40 km s{sup –1}.

  9. Functional and morphological changes in pancreatic remnant after pancreaticoduodenectomy.

    Science.gov (United States)

    Fang, Wen-Liang; Su, Cheng-Hsi; Shyr, Yi-Ming; Chen, Tien-Hua; Lee, Rheun-Chuan; Tai, Ling-Chen; Wu, Chew-Wun; Lui, Wing-Yiu

    2007-11-01

    Pancreatic exocrine insufficiency has been reported to be more common in pancreaticogastrostomy (PG) than in pancreaticojejunostomy (PJ) after pancreaticoduodenectomy (PD). This study aimed to evaluate the long-term outcome after PD between these 2 groups. We evaluated the long-term functional status of 42 surviving patients diagnosed with periampullary lesions who underwent PJ or PG after PD and followed up for more than 1 year. Among these, 23 patients underwent PJ and 19 patients underwent PG. To compare the 2 groups, we analyzed the (1) pancreatic exocrine insufficiency by questioning the presence or absence of steatorrhea, (2) pancreatic endocrine function by measuring glycohemoglobin A1c, fasting blood glucose, and history of new-onset diabetes, (3) nutritional status by measuring serum total protein, albumin, cholesterol, and triglyceride, (4) gastric emptying time, (5) panendoscopic findings, (6) changes of pancreatic duct diameter by computed tomography, and (7) relaparotomy rate. The mean follow-up time for PG and PJ were 37 +/- 23 and 103 +/- 52 months, respectively (P pancreatic exocrine insufficiency, and 11.9% had new-onset diabetes. There was no significant difference between PJ and PG groups. A significantly improved postoperative nutritional state regarding serum total protein and albumin were noticed in both groups. There was no significant difference in terms of gastric emptying time, positive panendoscopic findings, and changes in pancreatic duct diameter. The pancreatic remnant-related relaparotomy rate was higher in the PJ group as compared with the PG group (17.4% vs 0%; P = 0.056). There is no significant difference in pancreatic exocrine or endocrine insufficiency, gastric emptying time, and positive panendoscopic findings between PJ and PG. Pancreaticojejunostomy was associated with a higher pancreatic remnant-related relaparotomy rate; however, because of a shorter follow-up in the PG group, a continuous long-term follow-up is still

  10. Hubble Space Telescope Image, Supernova Remnant Cassiopeia A

    Science.gov (United States)

    2000-01-01

    The colorful streamers that float across the sky in this photo taken by NASA's Hubble Space Telescope (HST) were created by the universe's biggest firecracker, the titanic supernova explosion of a massive star. The light from the exploding star reached Earth 320 years ago, nearly a century before the United States celebrated its birth with a bang. The dead star's shredded remains are called Cassiopeia A, or 'Cas A' for short. Cas A is the youngest known supernova remnant in our Milky Way Galaxy and resides 10,000 light-years away in the constellation Cassiopeia, so the star actually blew up 10,000 years before the light reached Earth in the late 1600s. This HST image of Cas A shows for the first time that the debris is arranged into thousands of small, cooling knots of gas. This material eventually will be recycled into building new generations of stars and planets. Our own Sun and planets are constructed from the debris of supernovae that exploded billions of years ago. This photo shows the upper rim of the super nova remnant's expanding shell. Near the top of the image are dozens of tiny clumps of matter. Each small clump, originally just a small fragment of the star, is tens of times larger than the diameter of our solar system. The colors highlight parts of the debris where chemical elements are glowing. The dark blue fragments, for example, are richest in oxygen; the red material is rich in sulfur. The images were taken with the Wide Field and Planetary Camera 2 in January 2000 and January 2002. Image Credit: NASA and HST team (Stoics/AURA). Acknowledgment: R. Fesen (Darmouth) and J. Morse ( Univ. of Colorado).

  11. POPULATION III STARS AND REMNANTS IN HIGH-REDSHIFT GALAXIES

    International Nuclear Information System (INIS)

    Xu Hao; Norman, Michael L.; Wise, John H.

    2013-01-01

    Recent simulations of Population III star formation have suggested that some fraction form in binary systems, in addition to having a characteristic mass of tens of solar masses. The deaths of metal-free stars result in the initial chemical enrichment of the universe and the production of the first stellar-mass black holes. Here we present a cosmological adaptive mesh refinement simulation of an overdense region that forms a few 10 9 M ☉ dark matter halos and over 13,000 Population III stars by redshift 15. We find that most halos do not form Population III stars until they reach M vir ∼ 10 7 M ☉ because this biased region is quickly enriched from both Population III and galaxies, which also produce high levels of ultraviolet radiation that suppress H 2 formation. Nevertheless, Population III stars continue to form, albeit in more massive halos, at a rate of ∼10 –4 M ☉ yr –1 Mpc –3 at redshift 15. The most massive starless halo has a mass of 7 × 10 7 M ☉ , which could host massive black hole formation through the direct gaseous collapse scenario. We show that the multiplicity of the Population III remnants grows with halo mass above 10 8 M ☉ , culminating in 50 remnants located in 10 9 M ☉ halos on average. This has implications that high-mass X-ray binaries and intermediate-mass black holes that originate from metal-free stars may be abundant in high-redshift galaxies

  12. Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field

    NARCIS (Netherlands)

    Brienza, M.; Godfrey, L.; Morganti, R.; Prandoni, I.; Harwood, J.; Mahony, E. K.; Hardcastle, M. J.; Murgia, M.; Röttgering, H. J. A.; Shimwell, T. W.; Shulevski, A.

    2017-01-01

    Context. The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. Aims: In this work we present an extensive search for remnant radio galaxies in the Lockman Hole, a well-studied

  13. Effect of Hashimoto thyroiditis on low-dose radioactive-iodine remnant ablation.

    Science.gov (United States)

    Kwon, Hyungju; Choi, June Young; Moon, Jae Hoon; Park, Hyo Jin; Lee, Won Woo; Lee, Kyu Eun

    2016-04-01

    Radioactive-iodine remnant ablation is an integral part of the papillary thyroid carcinoma (PTC) treatment. Although a minimum dose is usually recommended, there is controversy as to whether the low-dose (1100 MBq) radioactive-iodine remnant ablation is adequate for selected patients. A retrospective cohort study was conducted on 691 patients. Patients with no remnant thyroid on the follow-up whole body scan and low stimulated thyroglobulin (sTg) level (Hashimoto thyroiditis based on histopathology diagnosis (odds ratio [OR] = 3.23; p Hashimoto thyroiditis and elevated sTg are negative predictive factors for successful low-dose radioactive-iodine remnant ablation treatment. An appropriate risk-adjusted approach may improve the efficacy of radioactive-iodine remnant ablation treatment. © 2015 Wiley Periodicals, Inc. Head Neck 38: E730-E735, 2016. © 2015 Wiley Periodicals, Inc.

  14. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans

    DEFF Research Database (Denmark)

    Bernelot Moens, Sophie J; Verweij, Simone L; Schnitzler, Johan G

    2017-01-01

    cholesterol accumulates in human hematopoietic stem and progenitor cells coinciding with myeloid skewing. CONCLUSIONS: Patients with FD have increased arterial wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing......OBJECTIVE: Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall...... inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD). APPROACH AND RESULTS: Arterial wall inflammation and bone marrow activity were measured using 18F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels...

  15. Fluid dynamics

    CERN Document Server

    Bernard, Peter S

    2015-01-01

    This book presents a focused, readable account of the principal physical and mathematical ideas at the heart of fluid dynamics. Graduate students in engineering, applied math, and physics who are taking their first graduate course in fluids will find this book invaluable in providing the background in physics and mathematics necessary to pursue advanced study. The book includes a detailed derivation of the Navier-Stokes and energy equations, followed by many examples of their use in studying the dynamics of fluid flows. Modern tensor analysis is used to simplify the mathematical derivations, thus allowing a clearer view of the physics. Peter Bernard also covers the motivation behind many fundamental concepts such as Bernoulli's equation and the stream function. Many exercises are designed with a view toward using MATLAB or its equivalent to simplify and extend the analysis of fluid motion including developing flow simulations based on techniques described in the book.

  16. Membrane paradigm

    International Nuclear Information System (INIS)

    Price, R.H.; Thorne, K.S.

    1986-01-01

    The membrane paradigm is a modified frozen star approach to modeling black holes, with particles and fields assuming a complex, static, boundary-layer type structure (membrane) near the event horizon. The membrane has no effects on the present or future evolution of particles and fields above itself. The mathematical representation is a combination of a formalism containing terms for the shear and bulk viscosity, surface pressure, momentum, temperature, entropy, etc., of the horizon and the 3+1 formalism. The latter model considers a family of three-dimensional spacelike hypersurfaces in one-dimensional time. The membrane model considers a magnetic field threading the hole and undergoing torque from the hole rotation. The field is cleaned by the horizon and distributed over the horizon so that ohmic dissipation is minimized. The membrane paradigm is invalid inside the horizon, but is useful for theoretically probing the properties of slowly evolving black holes

  17. Membrane processes

    Science.gov (United States)

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

  18. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    Science.gov (United States)

    Friesen, Dwayne T.; Babcock, Walter C.

    1989-01-01

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.

  19. Activation of Alkaline Irrigation Fluids in Endodontics

    Directory of Open Access Journals (Sweden)

    Laurence J. Walsh

    2017-10-01

    Full Text Available In conventional endodontic treatment, alkaline solutions of sodium hypochlorite (NaOCl and ethylenediaminetetraacetic acid (EDTA are used in combination to disinfect the root canal system and to eliminate debris and smear layers. An important concept that has emerged over recent years is the use of active physical methods for agitating these fluids to improve their penetration within areas that are not reached by endodontic instruments and to accelerate the chemical actions of these alkaline fluids against planktonic microorganisms, biofilms, soft tissue remnants and smear layers. Ultrasonic agitation and more recently pulsed lasers have emerged as two promising methods for activating endodontic irrigation fluids. Ultrasonic agitation with piezoelectric devices employs a moving tip, while laser agitation uses a stationary tip. Both methods cause cavitation, followed by implosions and shear forces which assist with debridement. Fluid streaming further enhances the activity of the fluids. While agitation enhances performance of irrigants, extrusion of fluids from the root canal during activation is a hazard that must be controlled.

  20. Importance of riparian remnants for frog species diversity in a highly fragmented rainforest.

    Science.gov (United States)

    Rodríguez-Mendoza, Clara; Pineda, Eduardo

    2010-12-23

    Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest.

  1. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans.

    Science.gov (United States)

    Bernelot Moens, Sophie J; Verweij, Simone L; Schnitzler, Johan G; Stiekema, Lotte C A; Bos, Merijn; Langsted, Anne; Kuijk, Carlijn; Bekkering, Siroon; Voermans, Carlijn; Verberne, Hein J; Nordestgaard, Børge G; Stroes, Erik S G; Kroon, Jeffrey

    2017-05-01

    Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD). Arterial wall inflammation and bone marrow activity were measured using 18 F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels and hematopoietic activity was validated in the CGPS (Copenhagen General Population Study). We found a 1.2-fold increase of 18 F-FDG uptake in the arterial wall in patients with FD (n=17, age 60±8 years, remnant cholesterol: 3.26 [2.07-5.71]) compared with controls (n=17, age 61±8 years, remnant cholesterol 0.29 [0.27-0.40]; P wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing to the increased cardiovascular disease risk in patients with FD. © 2017 American Heart Association, Inc.

  2. Cholesterol remnants and triglycerides are associated with decreased myocardial function in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Jørgensen, Peter Godsk; Jensen, Magnus Thorsten; Biering-Sørensen, Tor

    2016-01-01

    BACKGROUND: Recently, genetic studies have suggested a causal relationship between cholesterol remnants and ischemic heart disease. We aimed to determine whether cholesterol remnants and its marker, triglyceride levels, are associated with cardiac function as determined by sensitive echocardiogra......BACKGROUND: Recently, genetic studies have suggested a causal relationship between cholesterol remnants and ischemic heart disease. We aimed to determine whether cholesterol remnants and its marker, triglyceride levels, are associated with cardiac function as determined by sensitive...... secondary care centers. RESULTS: In multivariable analyses, triglycerides and cholesterol remnants were not associated with left ventricular ejection fraction, but with subtle measures of systolic function, including global longitudinal strain by speckle tracking and longitudinal displacement by tissue...... Doppler echocardiography: global longitudinal strain [0.33 % (0.14), p = 0.02 per doubling in cholesterol remnants and 0.28 % (0.13), p = 0.03 per doubling in triglyceride levels] and with longitudinal displacement [-0.25 mm (0.10), p = 0.01 per doubling in cholesterol remnants and -0.25 mm (0.09), p = 0...

  3. Influence of the Roof Movement Control Method on the Stability of Remnant

    Science.gov (United States)

    Adach-Pawelus, Karolina

    2017-12-01

    In the underground mines, there are geological and mining situations that necessitate leaving behind remnants in the mining field. Remnants, in the form of small, irregular parcels, are usually separated in the case of: significant problems with maintaining roof stability, high rockburst hazard, the occurrence of complex geological conditions and for random reasons (ore remnants), as well as for economic reasons (undisturbed rock remnants). Remnants left in the mining field become sites of high stress values concentration and may affect the rock in their vicinity. The values of stress inside the remnant and its vicinity, as well as the stability of the remnant, largely depend on the roof movement control method used in the mining field. The article presents the results of the numerical analysis of the influence of roof movement control method on remnant stability and the geomechanical situation in the mining field. The numerical analysis was conducted for the geological and mining conditions characteristic of Polish underground copper mines owned by KGHM Polska Miedz S.A. Numerical simulations were performed in a plane strain state by means of Phase 2 v. 8.0 software, based on the finite element method. The behaviour of remnant and rock mass in its vicinity was simulated in the subsequent steps of the room and pillar mining system for three types of roof movement control method: roof deflection, dry backfill and hydraulic backfill. The parameters of the rock mass accepted for numerical modelling were calculated by means of RocLab software on the basis of the Hoek-Brown classification. The Mohr-Coulomb strength criterion was applied.

  4. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...

  5. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

    International Nuclear Information System (INIS)

    Seward, F. D.; Charles, P. A.; Foster, D. L.; Dickel, J. R.; Romero, P. S.; Edwards, Z. I.; Perry, M.; Williams, R. M.

    2012-01-01

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M ☉

  6. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Seward, F. D. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Charles, P. A. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Foster, D. L. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Dickel, J. R.; Romero, P. S. [Department of Physics and Astronomy, University of New Mexico, 1919 Lomas Boulevard NE, Albuquerque, NM 87131 (United States); Edwards, Z. I.; Perry, M.; Williams, R. M. [Department of Earth and Space Sciences, Columbus State University, Coca Cola Space Science Center, 701 Front Avenue, Columbus, GA 31901 (United States)

    2012-11-10

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M {sub Sun}.

  7. Mucocele of the cystic duct remnant after orthotopic liver transplant: a problem revisited.

    Science.gov (United States)

    Chatterjee, Suvadip; Das, Debasish; Hudson, Mark; Bassendine, Margaret Fiona; Scott, John; Oppong, Kofi Ernest; Sen, Gourab; French, Jeremy J

    2011-06-01

    Mucocele of the cystic duct remnant is an uncommon hepatobiliary complication of a liver transplant. Current practice usually involves either excising the cystic duct, or incorporating the distal end of the transected cystic duct into the suture line of the biliary anastomosis to ensure drainage. We report a patient who developed cystic duct remnant mucocele after the latter approach was adopted. We believe that this is likely related to delayed anastomotic stricturing, which prevented draining from the remnant cystic duct. We also discuss the incidence, pathology, investigations, and treatment of this condition.

  8. Numerical code for fitting radial emission profile of a shell supernova remnant: Application

    Directory of Open Access Journals (Sweden)

    Opsenica Slobodan

    2011-01-01

    Full Text Available We present IDL (Interactive Data Language codes for fitting a theoretical emission profile of a shell supernova remnant (SNR to the mean profile of an SNR obtained from radio observations. Two considered theoretical models are: 1 a shell with constant emissivity and 2 a synchrotron shell with radially aligned magnetic field. The codes were applied to several observed supernova remnants. Good results are obtained in five considered cases, which justify the use of our code for remnants that are bright (so that observational errors are not large and spherically symmetric enough.

  9. Supernova remnant S147 and its associated neutron star(s)

    OpenAIRE

    Gvaramadze, V. V.

    2005-01-01

    The supernova remnant S147 harbors the pulsar PSR J0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic...

  10. Pervasive Defaunation of Forest Remnants in a Tropical Biodiversity Hotspot

    Science.gov (United States)

    Canale, Gustavo R.; Peres, Carlos A.; Guidorizzi, Carlos E.; Gatto, Cassiano A. Ferreira; Kierulff, Maria Cecília M.

    2012-01-01

    Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km2 study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0–14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ∼9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone. PMID:22905103

  11. Pervasive defaunation of forest remnants in a tropical biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Gustavo R Canale

    Full Text Available Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km(2 study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0-14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ~9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone.

  12. Cold H I clouds near the supernova remnant W44

    International Nuclear Information System (INIS)

    Sato, F.

    1986-01-01

    The cold H I clouds near the supernova remnant W44 are investigated by the use of the Maryland-Green Bank Survey (Westerhout 1973). Several clouds with a mean diameter of about 20 pc are distributed in the region. They do not seem to make a shell around W44, contrary to the suggestion by Knapp and Kerr (1974) based on the low-resolution data at coarse grids. Some of them form a chain, about 100 pc in length, extending approximately along the galactic equator. It resembles the cold H I cloud near W3 and W4. The major constituent of the clouds is probably the hydrogen molecule, and the total mass of the entire complex amounts to 25,000 81,000 solar masses. The estimated Jeans mass indicates that they will contract to dense molecular clouds. Therefore, it may safely be concluded that the cold H1 cloud complex near W44 is a giant molecular cloud at an early evolutionary stage. 14 references

  13. Comparing Neutron Star Kicks to Supernova Remnant Asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Holland-Ashford, Tyler; Lopez, Laura A. [The Ohio State University Department of Astronomy, 140 W 18th Avenue, Columbus, OH 43201 (United States); Auchettl, Katie [The Ohio State University Center for Cosmology and Astro-particle Physics, 191 West Woodruff Avenue, Columbus, OH 43210 (United States); Temim, Tea [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ramirez-Ruiz, Enrico, E-mail: holland-ashford.1@osu.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2017-07-20

    Supernova explosions are inherently asymmetric and can accelerate new-born neutron stars (NSs) to hundreds of km s{sup −1}. Two prevailing theories to explain NS kicks are ejecta asymmetries (e.g., conservation of momentum between NS and ejecta) and anisotropic neutrino emission. Observations of supernova remnants (SNRs) can give us insights into the mechanism that generates these NS kicks. In this paper, we investigate the relationship between NS kick velocities and the X-ray morphologies of 18 SNRs observed with the Chandra X-ray Observatory and the Röntgen Satellite ( ROSAT ). We measure SNR asymmetries using the power-ratio method (a multipole expansion technique), focusing on the dipole, quadrupole, and octupole power ratios. Our results show no correlation between the magnitude of the power ratios and NS kick velocities, but we find that for Cas A and G292.0+1.8, whose emission traces the ejecta distribution, their NSs are preferentially moving opposite to the bulk of the X-ray emission. In addition, we find a similar result for PKS 1209–51, CTB 109, and Puppis A; however, their emission is dominated by circumstellar/interstellar material, so their asymmetries may not reflect their ejecta distributions. Our results are consistent with the theory that NS kicks are a consequence of ejecta asymmetries as opposed to anisotropic neutrino emission. In the future, additional observations to measure NS proper motions within ejecta-dominated SNRs are necessary to robustly constrain the NS kick mechanism.

  14. Search for surviving companions in type Ia supernova remnants

    International Nuclear Information System (INIS)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E.

    2014-01-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  15. Fermi-LAT Observation of Supernova Remnant S147

    Energy Technology Data Exchange (ETDEWEB)

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; /SLAC /KIPAC, Menlo Park; Tajima, H.; /SLAC /KIPAC, Menlo Park /Nagoya U., Solar-Terrestrial Environ. Lab.; Bechtol, K.; Funk, S.; Lande, J.; /SLAC /KIPAC, Menlo Park; Ballet, J.; /AIM, Saclay; Hanabata, Y.; /Hiroshima U.; Lemoine-Goumard, M.; /CENBG, Gradignan; Takahashi, T.; /JAXA, Sagamihara

    2012-08-17

    We present an analysis of gamma-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region around SNR S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) x 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 x 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with prominent H{alpha} filaments of S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. Reacceleration of pre-existing CRs and subsequent adiabatic compression in the filaments is sufficient to provide the required energy density of high-energy protons.

  16. Evolution of Supernova Remnants Near the Galactic Center

    Energy Technology Data Exchange (ETDEWEB)

    Yalinewich, A.; Piran, T.; Sari, R. [Racah Institute of Physics, the Hebrew University, 91904, Jerusalem (Israel)

    2017-03-20

    Supernovae near the Galactic center (GC) evolve differently from regular Galactic supernovae. This is mainly due to the environment into which the supernova remnants (SNRs) propagate. SNRs near the GC propagate into a wind swept environment with a velocity directed away from the GC, and a graded density profile. This causes these SNRs to be non-spherical, and to evolve faster than their Galactic counterparts. We develop an analytic theory for the evolution of explosions within a stellar wind, and verify it using a hydrodynamic code. We show that such explosions can evolve in one of three possible morphologies. Using these results we discuss the association between the two SNRs (SGR East and SGR A’s bipolar radio/X-ray lobes) and the two neutron stars (the Cannonball and SGR J1745-2900) near the GC. We show that, given the morphologies of the SNR and positions of the neutron stars, the only possible association is between SGR A’s bipolar radio/X-ray lobes and SGR J1745-2900. If a compact object was created in the explosion of SGR East, it remains undetected, and the SNR of the supernova that created the Cannonball has already disappeared.

  17. Superdiffusion of relativistic electrons at supernova remnant shocks

    Science.gov (United States)

    Perri, Silvia

    2018-01-01

    Anomalous transport has been observed in various systems as nonlinear systems, numerical simulations of plasma turbulence, in laboratory plasmas, and recently in the propagation of energetic particles in the interplanetary space. Thanks to in situ observations it has been possible to deduce transport properties directly from spacecraft data. This technique has further found applicability to remote observations of relativistic electrons accelerated at supernova remnants (SNRs) shocks, pointing out that far upstream of the blast waves, the x-ray synchrotron emission, as captured by the Chandra spacecraft, is consistent with models of superdiffusive transport (i.e., transport faster than normal diffusive). Here we present and summarize evidences of superdiffusion both in the interplanetary space and upstream of SNRs shock fronts, in particular by analyzing, for the first time in the framework of superdiffusion, the transport properties of electrons accelerated at the young G1.9+0.3 SNR. We also briefly describe how this new model can be used to interpret radio emissions from electrons accelerated at shocks forming during galaxy cluster mergers.

  18. EXPECTATION ON OBSERVATION OF SUPERNOVA REMNANTS WITH THE LHAASO PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Huang, Xingtao [School of Physics and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China); Cao, Zhen; Chen, Songzhan; He, Huihai; Ma, Xinhua [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, Yang; Zhang, Xiao [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Cui, Shuwang [The College of Physics Science and Information Engineering, Hebei Normal University, Shijiazhuang, 050016 (China); Yuan, Qiang, E-mail: huangxt@sdu.edu.cn, E-mail: maxh@ihep.ac.cn [Department of Astronomy, University of Massachusetts, 710 North Pleasant St., Amherst, MA 01003 (United States); Collaboration: On behalf of the LHAASO Collaboration

    2016-07-20

    Supernova remnants (SNRs) are believed to be the most important acceleration sites for cosmic rays (CRs) below ∼10{sup 15} eV in the Galaxy. High-energy photons, either directly from the shocks of the SNRs or indirectly from the interaction between SNRs and the nearby clouds, are crucial probes for the CR acceleration. Big progresses on observations of SNRs have been achieved by space- and ground-based γ -ray facilities. However, whether γ -rays come from accelerated hadrons or not, as well as their connection with the CRs observed at Earth, remains in debate. Large High Altitude Air Shower Observatory (LHAASO), a next-generation experiment, is designed to survey the northern part of the very high energy γ -ray sky from ∼0.3 TeV to PeV with the sensitivity of ≲1% of the Crab Nebula flux. In this paper, we indicate that LHAASO will be dedicated to enlarging the γ -ray SNR samples and improving the spectral and morphological measurements. These measurements, especially at energies above 30 TeV, will be important for us to finally understand the CR acceleration in SNRs.

  19. THE FATE OF THE COMPACT REMNANT IN NEUTRON STAR MERGERS

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, Chris L. [Department of Physics, The University of Arizona, Tucson, AZ 85721 (United States); Belczynski, Krzysztoff [Astronomical Observatory, University of Warsaw, Al Ujazdowskie 4, 00-478 Warsaw (Poland); Ramirez-Ruiz, Enrico [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Rosswog, Stephan [The Oskar klein Center, Department of Astronomy, AlbaNova, Stockholm University, SE-106 91 Stockholm (Sweden); Shen, Gang [Institute for Nuclear Theory, University of Washington, Seattle, WA 98195 (United States); Steiner, Andrew W. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)

    2015-10-10

    Neutron star (binary neutron star and neutron star–black hole) mergers are believed to produce short-duration gamma-ray bursts (GRBs). They are also believed to be the dominant source of gravitational waves to be detected by the advanced LIGO and advanced VIRGO and the dominant source of the heavy r-process elements in the universe. Whether or not these mergers produce short-duration GRBs depends sensitively on the fate of the core of the remnant (whether, and how quickly, it forms a black hole). In this paper, we combine the results of Newtonian merger calculations and equation of state studies to determine the fate of the cores of neutron star mergers. Using population studies, we can determine the distribution of these fates to compare to observations. We find that black hole cores form quickly only for equations of state that predict maximum non-rotating neutron star masses below 2.3–2.4 solar masses. If quick black hole formation is essential in producing GRBs, LIGO/Virgo observed rates compared to GRB rates could be used to constrain the equation of state for dense nuclear matter.

  20. The Population of Supernova Remnants in M51

    Science.gov (United States)

    Long, Knox S.; Blair, William P.; Kuntz, K. D.; Winkler, P. Frank

    2017-08-01

    The nearby, actively star-forming, nearly face-on spiral galaxy, M51 (NGC 5194/5), has been the site of four supernovae since 1941. As a result it should have a rich population of young supernova remnants (SNRs). Here we describe a search for optical SNRs in M51 among the 298 X-ray sources discovered inside the D25 contour in deep Chandra observations. The search uses interference filter images obtained with the WFC3 on Hubble Space Telescope and more recent images from GMOS on Gemini North. Of 80 emission nebulae identified in the HST images as SNR candidates based on elevated [SII]: Ha ratios compared to HII regions, 40 have X-ray counterparts. The diameters of the SNRs and SNR candidates detected with HST are systematically smaller than seen in SNR populations of other galaxies at comparable distances. However, this is most likely an instrumental effect, which our ongoing analysis of the new GMOS images will correct. At that point, we will be able to make of fair multi-wavelength comparison of the SNR population in M51 with other nearby, actively star-forming spiral galaxies, such as M83 and NGC6946.

  1. Acceleration of cosmic rays in supernova-remnants

    Science.gov (United States)

    Dorfi, E. A.; Drury, L. O.

    1985-01-01

    It is commonly accepted that supernova-explosions are the dominant source of cosmic rays up to an energy of 10 to the 14th power eV/nucleon. Moreover, these high energy particles provide a major contribution to the energy density of the interstellar medium (ISM) and should therefore be included in calculations of interstellar dynamic phenomena. For the following the first order Fermi mechanism in shock waves are considered to be the main acceleration mechanism. The influence of this process is twofold; first, if the process is efficient (and in fact this is the cas) it will modify the dynamics and evolution of a supernova-remnant (SNR), and secondly, the existence of a significant high energy component changes the overall picture of the ISM. The complexity of the underlying physics prevented detailed investigations of the full non-linear selfconsistent problem. For example, in the context of the energy balance of the ISM it has not been investigated how much energy of a SN-explosion can be transfered to cosmic rays in a time-dependent selfconsistent model. Nevertheless, a lot of progress was made on many aspects of the acceleration mechanism.

  2. Acceleration of cosmic rays in supernova-remnants

    International Nuclear Information System (INIS)

    Dorfi, E.A.; Drury, L.O.

    1985-01-01

    It is commonly accepted that supernova-explosions are the dominant source of cosmic rays up to an energy of 10 to the 14th power eV/nucleon. Moreover, these high energy particles provide a major contribution to the energy density of the interstellar medium (ISM) and should therefore be included in calcuations of interstellar dynamic phenomena. For the following the first order Fermi mechanism in shock waves are considered to be the main acceleration mechanism. The influence of this process is twofold; first, if the process is efficient (and in fact this is the case) it will modify the dynamics and evolution of a supernova-remnant (SNR), and secondly, the existence of a significant high energy component changes the overall picture of the ISM. The complexity of the underlying physics prevented detailed investigations of the full non-linear selfconsistent problem. For example, in the context of the energy balance of the ISM it has not been investigated how much energy of a SN-explosion can be transfered to cosmic rays in a time-dependent selfconsistent model. Nevertheless, a lot of progress was made on many aspects of the acceleration mechnism

  3. The high energy X-ray spectra of supernova remnants

    Science.gov (United States)

    Pravdo, S. H.; Nugent, J. J.

    The results of fitting an ionization-nonequilibrium (INE) model to the high-energy (above 5-keV) X-ray spectra of the young supernova remnants Cas A and Tycho are presented. As an additional constraint, the models must simultaneously fit lower-energy, higher-resolution data. For Cas A, a single INE component cannot adequately reproduce the features for the entire X-ray spectrum because the ionization structure of iron ions responsible for the K emission is inconsistent with that of the ions responsible for the lower-energy lines, and the flux of the highest-energy X-rays is underestimated. The iron K line and the high-energy continuum could arise from the same INE component, but the identification of this component with either the blast wave or the ejecta in the standard model is difficult. In Tycho, the high-energy data rule out a class of models for the lower-energy data which have too large a continuum contribution.

  4. Effective tension and fluctuations in active membranes.

    Science.gov (United States)

    Loubet, Bastien; Seifert, Udo; Lomholt, Michael Andersen

    2012-03-01

    We calculate the fluctuation spectrum of the shape of a lipid vesicle or cell exposed to a nonthermal source of noise. In particular, we take constraints on the membrane area and the volume of fluid that it encapsulates into account when obtaining expressions for the dependency of the membrane tension on the noise. We then investigate three possible origins of the nonthermal noise taken from the literature: A direct force, which models an external medium pushing on the membrane, a curvature force, which models a fluctuating spontaneous curvature, and a permeation force coming from an active transport of fluid through the membrane. For the direct force and curvature force cases, we compare our results to existing experiments on active membranes.

  5. Membranous nephropathy

    Science.gov (United States)

    ... skin-lightening creams Systemic lupus erythematosus , rheumatoid arthritis, Graves disease, and other autoimmune disorders The disorder occurs at ... diagnosis. The following tests can help determine the cause of membranous nephropathy: Antinuclear antibodies test Anti-double- ...

  6. A multifrequency study of the radio structure of 3C10, the remnant of Tycho's supernova

    International Nuclear Information System (INIS)

    Duin, R.M.; Strom, R.G.

    1975-01-01

    Synthesis observations of 3C10 have been made at 6 cm and 50 cm using the Westerbork telescope. Combining these results with earlier 21 cm Westerbork maps, we have made detailed comparisons between the three wavelengths. The total intensity maps are remarkably similar: we find no evidence for changes in the spectral index of small scale features around the rim of the shell-like remnant. On the large scale, however, there appears to be a significant steepening of the spectrum near the center of 3C10. We believe this to be related to the fact that the integrated radio spectrum steepens at low frequencies, and suggest that particles presently near the outer boundary may be accelerated with a relatively flat energy spectrum. Although no linear polarization exceeding about 1% of the total intensity could be detected at 50 cm, at 6 cm the polarized emission is quite smooth, being typically 10% of the total intensity. The position angle distribution of the linear polarization is also smooth, confirming our earlier conclusion that 3C10 is surrounded by an irregular Faraday screen. By comparing our 6 cm map with 2.8 cm and 10.4 cm results we are able to construct a rotation measure map, and confirm that the intrinsic position angles are tangentially aligned, with an average rotation measure of -249 rad m -2 . We conclude that the ordered component of the magnetic field is radially directed, and suggest that the mechanism for producing such a configuration can be found in the Sedov solution for shock waves in a fluid medium. (orig.) [de

  7. Chylomicron remnant-vitamin A metabolism by the human hepatoma cell line HepG2

    International Nuclear Information System (INIS)

    Lenich, C.M.

    1985-01-01

    The binding and metabolism of [ 3 H] vitamin A-containing chylomicron remnants (CMR) by the human hepatoma cell line Hep G2 was studied. Mesenteric lymph chylomicrons (CM) were collected from [ 3 H] retinol-fed rats and incubated with lipoprotein-lipase to obtain CMR. At 4 0 C, specific CMR binding was inhibited by excess unlabeled CMR. Specific binding predominated at low concentrations and approached saturation while total binding continued to increase over an extensive concentration range (0.45-32 μg triglyceride/ml). CMR uptake at 37 0 C was greater than that of CM and at least 100 times more efficient than the fluid-phase pinocytosis of sucrose. CMR binding increased as the extent of lipolysis obtained by incubation with lipoprotein-lipase increased. Addition of human apolipoprotein E enhanced both CMR and CM binding. After internalization, Hep G2 cells hydrolyzed CMR-[ 3 H]retinyl esters and radiolabeled metabolites accumulated as a function of time and temperature. As a function of the concentration of [ 3 H] VA initially cell-bound, retinol and retinyl esters accumulated as the major cell-associated metabolites. By contrast, retinol was the major metabolite in the medium only at low VA concentrations as other more polar metabolites accumulated at higher concentrations (> 110 pmol VA/mg cell protein). The accumulation of CMR-VA metabolites in the medium was reduced when cells were preincubated in retinol-supplemented media. Also, the specific activity of retinol in the medium closely resembled that in the cell indicating that CMR-VA mixed with the cellular store prior to its secretion

  8. Molecular organization in bacterial cell membranes

    International Nuclear Information System (INIS)

    Larraga, V.; Munoz, E.

    1975-01-01

    The paper reports about an investigation into the question of the specific labelling and topological distribution of glycoproteins and proteins in Streptomyces albus membranes. The method of sample preparation is described: Tritium labelling of glycoproteins in protoplasts and membranes, iodination of proteins, trypsin treatment and polyacrylamide gel electrophoresis. The findings suggest an asymmetrical distribution of the glycoproteins in membranes and a weak accessibility to iodine label. A structural model of the plasma membranes of Streptomyces albus is proposed similar to the general 'fluid mosaic' model of Singer and Nicholson. (BSC) [de

  9. Fluid mechanics

    International Nuclear Information System (INIS)

    Granger, R.A.

    1985-01-01

    This text offers the most comprehensive approach available to fluid mechanics. The author takes great care to insure a physical understanding of concepts grounded in applied mathematics. The presentation of theory is followed by engineering applications, helping students develop problem-solving skills from the perspective of a professional engineer. Extensive use of detailed examples reinforces the understanding of theoretical concepts

  10. Evolution and development of model membranes for physicochemical and functional studies of the membrane lateral heterogeneity.

    Science.gov (United States)

    Morigaki, Kenichi; Tanimoto, Yasushi

    2018-03-14

    One of the main questions in the membrane biology is the functional roles of membrane heterogeneity and molecular localization. Although segregation and local enrichment of protein/lipid components (rafts) have been extensively studied, the presence and functions of such membrane domains still remain elusive. Along with biochemical, cell observation, and simulation studies, model membranes are emerging as an important tool for understanding the biological membrane, providing quantitative information on the physicochemical properties of membrane proteins and lipids. Segregation of fluid lipid bilayer into liquid-ordered (Lo) and liquid-disordered (Ld) phases has been studied as a simplified model of raft in model membranes, including giant unilamellar vesicles (GUVs), giant plasma membrane vesicles (GPMVs), and supported lipid bilayers (SLB). Partition coefficients of membrane proteins between Lo and Ld phases were measured to gauze their affinities to lipid rafts (raftophilicity). One important development in model membrane is patterned SLB based on the microfabrication technology. Patterned Lo/Ld phases have been applied to study the partition and function of membrane-bound molecules. Quantitative information of individual molecular species attained by model membranes is critical for elucidating the molecular functions in the complex web of molecular interactions. The present review gives a short account of the model membranes developed for studying the lateral heterogeneity, especially focusing on patterned model membranes on solid substrates. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. The majority of lipoprotein lipase in plasma is bound to remnant lipoproteins: A new definition of remnant lipoproteins.

    Science.gov (United States)

    Sato, Koichi; Okajima, Fumikazu; Miyashita, Kazuya; Imamura, Shigeyuki; Kobayashi, Junji; Stanhope, Kimber L; Havel, Peter J; Machida, Tetsuo; Sumino, Hiroyuki; Murakami, Masami; Schaefer, Ernst; Nakajima, Katsuyuki

    2016-10-01

    Lipoprotein lipase (LPL) is a multifunctional protein and a key enzyme involved in the regulation of lipoprotein metabolism. We determined the lipoproteins to which LPL is bound in the pre-heparin and post-heparin plasma. Tetrahydrolipstatin (THL), a potent inhibitor of serine lipases, was used to block the lipolytic activity of LPL, thereby preventing changes in the plasma lipoproteins due to ex vivo lipolysis. Gel filtration was performed to obtain the LPL elution profiles in plasma and the isolated remnant lipoproteins (RLP). When ex vivo lipolytic activity was inhibited by THL in the post-heparin plasma, majority of the LPL was found in the VLDL elution range, specifically in the RLP as inactive dimers. However, in the absence of THL, most of the LPL was found in the HDL elution range as active dimers. Furthermore, majority of the LPL in the pre-heparin plasma was found in the RLP as inactive form, with broadly diffused lipoprotein profiles in the presence and absence of THL. It is suggested that during lipolysis in vivo, the endothelial bound LPL dimers generates RLP, forming circulating RLP-LPL complexes in an inactive form that subsequently binds and initiates receptor-mediated catabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Analyzing Data Remnant Remains on User Devices to Determine Probative Artifacts in Cloud Environment.

    Science.gov (United States)

    Ahmed, Abdulghani Ali; Xue Li, Chua

    2018-01-01

    Cloud storage service allows users to store their data online, so that they can remotely access, maintain, manage, and back up data from anywhere via the Internet. Although helpful, this storage creates a challenge to digital forensic investigators and practitioners in collecting, identifying, acquiring, and preserving evidential data. This study proposes an investigation scheme for analyzing data remnants and determining probative artifacts in a cloud environment. Using pCloud as a case study, this research collected the data remnants available on end-user device storage following the storing, uploading, and accessing of data in the cloud storage. Data remnants are collected from several sources, including client software files, directory listing, prefetch, registry, network PCAP, browser, and memory and link files. Results demonstrate that the collected remnants data are beneficial in determining a sufficient number of artifacts about the investigated cybercrime. © 2017 American Academy of Forensic Sciences.

  13. Remnant pancreatic parenchymal volume predicts postoperative pancreatic exocrine insufficiency after pancreatectomy.

    Science.gov (United States)

    Okano, Keisuke; Murakami, Yoshiaki; Nakagawa, Naoya; Uemura, Kenichiro; Sudo, Takeshi; Hashimoto, Yasushi; Kondo, Naru; Takahashi, Shinya; Sueda, Taijiro

    2016-03-01

    Pancreatectomy, including pancreatoduodenectomy and distal pancreatectomy, often causes postoperative pancreatic exocrine insufficiency (PEI). Our aim was to clarify a relationship between remnant pancreatic volume and postoperative PEI. A total of 227 patients who underwent pancreatoduodenectomy or distal pancreatectomy were enrolled in this study. All patients underwent a (13)C-labeled mixed triglyceride breath test to assess pancreatic exocrine function and abdominal dynamic computed tomography for assessing remnant pancreatic volume after pancreatectomy at a median of 7 months postoperatively. The percent (13)CO2 cumulative dose at 7 hours (% dose (13)C cum 7 h) pancreatectomy were performed in 174 (76.7%) and 53 (23.3%) patients, respectively. Of the 227 patients, 128 (56.3%) developed postoperative PEI. Postoperative % dose (13)C cum 7 h was strongly correlated with remnant pancreatic volume (r = .509, P pancreatectomy (P pancreatectomy. Remnant pancreatic volume may predict postoperative PEI in patients who undergo pancreatectomy. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Remnant for all black objects due to gravity's rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag, E-mail: afarag@zewailcity.edu.eg [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Center for Fundamental Physics, Zewail City of Science and Technology, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University, Benha 13518 (Egypt); Faizal, Mir, E-mail: f2mir@uwaterloo.ca [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Khalil, Mohammed M., E-mail: moh.m.khalil@gmail.com [Department of Electrical Engineering, Alexandria University, Alexandria 12544 (Egypt)

    2015-05-15

    We argue that a remnant is formed for all black objects in gravity's rainbow. This will be based on the observation that a remnant depends critically on the structure of the rainbow functions, and this dependence is a model independent phenomena. We thus propose general relations for the modified temperature and entropy of all black objects in gravity's rainbow. We explicitly check this to be the case for Kerr, Kerr–Newman-dS, charged-AdS, and higher dimensional Kerr–AdS black holes. We also try to argue that a remnant should form for black saturn in gravity's rainbow. This work extends our previous results on remnants of Schwarzschild black holes and black rings.

  15. Collection of apoplastic fluids from Arabidopsis thaliana leaves

    DEFF Research Database (Denmark)

    Madsen, Svend Roesen; Nour-Eldin, Hussam Hassan; Halkier, Barbara Ann

    2016-01-01

    The leaf apoplast comprises the extracellular continuum outside cell membranes. A broad range of processes take place in the apoplast, including intercellular signaling, metabolite transport, and plant-microbe interactions. To study these processes, it is essential to analyze the metabolite conte...... in apoplastic fluids. Due to the fragile nature of leaf tissues, it is a challenge to obtain apoplastic fluids from leaves. Here, methods to collect apoplastic washing fluid and guttation fluid from Arabidopsis thaliana leaves are described....

  16. Remnant cholesterol as a causal risk factor for ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Tybjærg-Hansen, Anne

    2013-01-01

    The aim of this study was to test the hypothesis that elevated nonfasting remnant cholesterol is a causal risk factor for ischemic heart disease independent of reduced high-density lipoprotein (HDL) cholesterol.......The aim of this study was to test the hypothesis that elevated nonfasting remnant cholesterol is a causal risk factor for ischemic heart disease independent of reduced high-density lipoprotein (HDL) cholesterol....

  17. STAR FORMATION ASSOCIATED WITH THE SUPERNOVA REMNANT IC443

    International Nuclear Information System (INIS)

    Xu Jinlong; Wang Junjie; Miller, Martin

    2011-01-01

    We have performed submillimeter and millimeter observations in CO lines toward supernova remnant (SNR) IC443. The CO molecular shell coincides well with the partial shell of the SNR detected in radio continuum observations. Broad emission lines and three 1720 MHz OH masers were detected in the CO molecular shell. The present observations have provided further evidence in support of the interaction between the SNR and the adjoining molecular clouds (MCs). The total mass of the MCs is 9.26 x 10 3 M sun . The integrated CO line intensity ratio (R I CO(3-2) /I CO(2-1) ) for the whole MC is between 0.79 and 3.40. The average value is 1.58, which is much higher than previous measurements of individual Galactic MCs. Higher line ratios imply that shocks have driven into the MCs. We conclude that high R I CO(3-2) /I CO(2-1) is identified as a good signature of the SNR-MC interacting system. Based on the IRAS Point Source Catalog and the Two Micron All Sky Survey near-infrared database, 12 protostellar object and 1666 young stellar object (YSO) candidates (including 154 classical T Tauri stars and 419 Herbig Ae/Be stars) are selected. In the interacting regions, the significant enhancement of the number of protostellar objects and YSOs indicates the presence of some recently formed stars. After comparing the characteristic timescales of star formation with the age of IC443, we conclude that the protostellar objects and YSO candidates are not triggered by IC443. For the age of the stellar winds shell, we have performed our calculation on the basis of a stellar wind shell expansion model. The results and analysis suggest that the formation of these stars may be triggered by the stellar winds of the IC443 progenitor.

  18. Interstellar and ejecta dust in the cas a supernova remnant

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, Richard G. [CRESST, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Dwek, Eli; Kober, Gladys [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Rho, Jeonghee [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Hwang, Una, E-mail: Richard.G.Arendt@nasa.gov [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2014-05-01

    Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant (SNR). Using low-resolution Spitzer IRS spectra (5-35 μm), and broad-band Herschel PACS imaging (70, 100, and 160 μm), we identify characteristic dust spectra, associated with ejecta layers that underwent distinct nuclear burning histories. The most luminous spectrum exhibits strong emission features at ∼9 and 21 μm and is closely associated with ejecta knots with strong Ar emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low Mg to Si ratios. Another dust spectrum is associated with ejecta having strong Ne emission lines. It has no indication of any silicate features and is best fit by Al{sub 2}O{sub 3} dust. A third characteristic dust spectrum shows features that are best matched by magnesium silicates with a relatively high Mg to Si ratio. This dust is primarily associated with the X-ray-emitting shocked ejecta, but it is also evident in regions where shocked interstellar or circumstellar material is expected. However, the identification of dust composition is not unique, and each spectrum includes an additional featureless dust component of unknown composition. Colder dust of indeterminate composition is associated with emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. Most of the dust mass in Cas A is associated with this unidentified cold component, which is ≲ 0.1 M {sub ☉}. The mass of warmer dust is only ∼0.04 M {sub ☉}.

  19. Putative nanobacteria represent physiological remnants and culture by-products of normal calcium homeostasis.

    Directory of Open Access Journals (Sweden)

    John D Young

    Full Text Available Putative living entities called nanobacteria (NB are unusual for their small sizes (50-500 nm, pleomorphic nature, and accumulation of hydroxyapatite (HAP, and have been implicated in numerous diseases involving extraskeletal calcification. By adding precipitating ions to cell culture medium containing serum, mineral nanoparticles are generated that are morphologically and chemically identical to the so-called NB. These nanoparticles are shown here to be formed of amorphous mineral complexes containing calcium as well as other ions like carbonate, which then rapidly acquire phosphate, forming HAP. The main constituent proteins of serum-derived NB are albumin, fetuin-A, and apolipoprotein A1, but their involvement appears circumstantial since so-called NB from different body fluids harbor other proteins. Accordingly, by passage through various culture media, the protein composition of these particles can be modulated. Immunoblotting experiments reveal that antibodies deemed specific for NB react in fact with either albumin, fetuin-A, or both, indicating that previous studies using these reagents may have detected these serum proteins from the same as well as different species, with human tissue nanoparticles presumably absorbing bovine serum antigens from the culture medium. Both fetal bovine serum and human serum, used earlier by other investigators as sources of NB, paradoxically inhibit the formation of these entities, and this inhibition is trypsin-sensitive, indicating a role for proteins in this inhibitory process. Fetuin-A, and to a lesser degree albumin, inhibit nanoparticle formation, an inhibition that is overcome with time, ending with formation of the so-called NB. Together, these data demonstrate that NB are most likely formed by calcium or apatite crystallization inhibitors that are somehow overwhelmed by excess calcium or calcium phosphate found in culture medium or in body fluids, thereby becoming seeds for calcification. The

  20. Remnant radio-loud AGN in the Herschel-ATLAS field

    Science.gov (United States)

    Mahatma, V. H.; Hardcastle, M. J.; Williams, W. L.; Brienza, M.; Brüggen, M.; Croston, J. H.; Gurkan, G.; Harwood, J. J.; Kunert-Bajraszewska, M.; Morganti, R.; Röttgering, H. J. A.; Shimwell, T. W.; Tasse, C.

    2018-04-01

    Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting `remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of Low-Frequency Array (LOFAR) and the Very Large Array, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indices (-1.5≤slant α ^{1400}_{150}≤slant -0.5), confirming that the lobes of some remnants may possess flat spectra at low frequencies just as active sources do. We suggest that, even with the unprecedented sensitivity of LOFAR, our sample may still only contain the youngest of the remnant population.

  1. Fluid dynamics of dilatant fluid

    DEFF Research Database (Denmark)

    Nakanishi, Hiizu; Nagahiro, Shin-ichiro; Mitarai, Namiko

    2012-01-01

    of the state variable, we demonstrate that the model can describe basic features of the dilatant fluid such as the stress-shear rate curve that represents discontinuous severe shear thickening, hysteresis upon changing shear rate, and instantaneous hardening upon external impact. An analysis of the model...

  2. Fluid dynamics

    CERN Document Server

    Ruban, Anatoly I

    This is the first book in a four-part series designed to give a comprehensive and coherent description of Fluid Dynamics, starting with chapters on classical theory suitable for an introductory undergraduate lecture course, and then progressing through more advanced material up to the level of modern research in the field. The present Part 1 consists of four chapters. Chapter 1 begins with a discussion of Continuum Hypothesis, which is followed by an introduction to macroscopic functions, the velocity vector, pressure, density, and enthalpy. We then analyse the forces acting inside a fluid, and deduce the Navier-Stokes equations for incompressible and compressible fluids in Cartesian and curvilinear coordinates. In Chapter 2 we study the properties of a number of flows that are presented by the so-called exact solutions of the Navier-Stokes equations, including the Couette flow between two parallel plates, Hagen-Poiseuille flow through a pipe, and Karman flow above an infinite rotating disk. Chapter 3 is d...

  3. Axionic membranes

    International Nuclear Information System (INIS)

    Aurilia, A.; Spallucci, E.

    1992-01-01

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramand gauge potential B μν (x) and the ring by a closed string. The interaction between the B μν field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the HJ theory of electromagnetic strings. (orig.)

  4. Metamaterial membranes

    International Nuclear Information System (INIS)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2017-01-01

    We introduce a new class of metamaterial device to achieve separation of compounds by using coordinate transformations and metamaterial theory. By rationally designing the spatial anisotropy for mass diffusion, we simultaneously concentrate different compounds in different spatial locations, leading to separation of mixtures across a metamaterial membrane. The separation of mixtures into their constituent compounds is critically important in biophysics, biomedical, and chemical applications. We present a practical case where a mixture of oxygen and nitrogen diffusing through a polymeric planar matrix is separated. This work opens doors to new paradigms in membrane separations via coordinate transformations and metamaterials by introducing novel properties and unconventional mass diffusion phenomena. (paper)

  5. Hydrogen concentration control utilizing a hydrogen permeable membrane

    International Nuclear Information System (INIS)

    Keating, S.J. Jr.

    1976-01-01

    The concentration of hydrogen in a fluid mixture is controlled to a desired concentration by flowing the fluid through one chamber of a diffusion cell separated into two chambers by a hydrogen permeable membrane. A gradient of hydrogen partial pressure is maintained across the membrane to cause diffusion of hydrogen through the membrane to maintain the concentration of hydrogen in the fluid mixture at the predetermined level. The invention has particular utility for the purpose of injecting into and/or separating hydrogen from the reactor coolant of a nuclear reactor system

  6. [3H]acetylcholine synthesis in cultured ciliary ganglion neurons: effects of myotube membranes

    International Nuclear Information System (INIS)

    Gray, D.B.; Tuttle, J.B.

    1987-01-01

    Avian ciliary ganglion neurons in cell culture were examined for the capacity to synthesize acetylcholine (ACh) from the exogenously supplied precursor, choline. Relevant kinetic parameters of the ACh synthetic system in cultured neurons were found to be virtually the same as those of the ganglionic terminals in the intact iris. Neurons were cultured in the presence of and allowed to innervate pectoral muscle; this results in an capacity for ACh synthesis. In particular, the ability to increase ACh synthesis upon demand after stimulation is affected by interaction with the target. This effect is shown to be an acceleration of the maturation of the cultured neurons. Lysed and washed membrane remnants of the muscle target were able to duplicate, in part, this effect of live target tissue on neuronal transmitter metabolism. Culture medium conditioned by muscle, and by the membrane remnants of muscle, was without significant effect. Thus, substances secreted into the medium do not play a major role in this interaction. Neurons cultured with either muscle or muscle membrane remnants formed large, elongate structures on the target membrane surface. These were not seen in the absence of the target at the times examined. This morphological difference in terminal-like structures may parallel the developmental increases in size and vesicular content of ciliary ganglion nerve terminals in the chick iris, and may relate to the increased ACh synthetic activity. The results suggest that direct contact with an appropriate target membrane has a profound, retrograde influence upon neuronal metabolic and morphological maturation

  7. SUPERNOVA 1987A: A TEMPLATE TO LINK SUPERNOVAE TO THEIR REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F., E-mail: orlando@astropa.inaf.it [INAF—Osservatorio Astronomico di Palermo “G.S. Vaiana”, Piazza del Parlamento 1, I-90134 Palermo (Italy)

    2015-09-10

    The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2–1.4 × 10{sup 51} erg and the envelope mass in the range 15–17 M{sub ⊙}. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = −8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

  8. Examining hemodialyzer membrane performance using proteomic technologies.

    Science.gov (United States)

    Bonomini, Mario; Pieroni, Luisa; Di Liberato, Lorenzo; Sirolli, Vittorio; Urbani, Andrea

    2018-01-01

    The success and the quality of hemodialysis therapy are mainly related to both clearance and biocompatibility properties of the artificial membrane packed in the hemodialyzer. Performance of a membrane is strongly influenced by its interaction with the plasma protein repertoire during the extracorporeal procedure. Recognition that a number of medium-high molecular weight solutes, including proteins and protein-bound molecules, are potentially toxic has prompted the development of more permeable membranes. Such membrane engineering, however, may cause loss of vital proteins, with membrane removal being nonspecific. In addition, plasma proteins can be adsorbed onto the membrane surface upon blood contact during dialysis. Adsorption can contribute to the removal of toxic compounds and governs the biocompatibility of a membrane, since surface-adsorbed proteins may trigger a variety of biologic blood pathways with pathophysiologic consequences. Over the last years, use of proteomic approaches has allowed polypeptide spectrum involved in the process of hemodialysis, a key issue previously hampered by lack of suitable technology, to be assessed in an unbiased manner and in its full complexity. Proteomics has been successfully applied to identify and quantify proteins in complex mixtures such as dialysis outflow fluid and fluid desorbed from dialysis membrane containing adsorbed proteins. The identified proteins can also be characterized by their involvement in metabolic and signaling pathways, molecular networks, and biologic processes through application of bioinformatics tools. Proteomics may thus provide an actual functional definition as to the effect of a membrane material on plasma proteins during hemodialysis. Here, we review the results of proteomic studies on the performance of hemodialysis membranes, as evaluated in terms of solute removal efficiency and blood-membrane interactions. The evidence collected indicates that the information provided by proteomic

  9. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor; Villalobos Vazquez de la Parra, Luis Francisco; Hilke, Roland

    2015-01-01

    microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  10. Fluid mechanics

    International Nuclear Information System (INIS)

    Paraschivoiu, I.; Prud'homme, M.; Robillard, L.; Vasseur, P.

    2003-01-01

    This book constitutes at the same time theoretical and practical base relating to the phenomena associated with fluid mechanics. The concept of continuum is at the base of the approach developed in this work. The general advance proceeds of simple balances of forces as into hydrostatic to more complex situations or inertias, the internal stresses and the constraints of Reynolds are taken into account. This advance is not only theoretical but contains many applications in the form of solved problems, each chapter ending in a series of suggested problems. The major part of the applications relates to the incompressible flows

  11. BMS invariance and the membrane paradigm

    International Nuclear Information System (INIS)

    Penna, Robert F.

    2016-01-01

    The Bondi-van der Burg-Metzner-Sachs (BMS) group is the asymptotic symmetry group of asymptotically flat spacetime. It is infinite dimensional and entails an infinite number of conservation laws. According to the black hole membrane paradigm, null infinity (in asymptotically flat spacetime) and black hole event horizons behave like fluid membranes. The fluid dynamics of the membrane is governed by an infinite set of symmetries and conservation laws. Our main result is to point out that the infinite set of symmetries and conserved charges of the BMS group and the membrane paradigm are the same. This relationship has several consequences. First, it sheds light on the physical interpretation of BMS conservation laws. Second, it generalizes the BMS conservation laws to arbitrary subregions of arbitrary null surfaces. Third, it clarifies the identification of the superrotation subgroup of the BMS group. We briefly comment on the black hole information problem.

  12. Principles of fluid mechanics

    International Nuclear Information System (INIS)

    Kreider, J.F.

    1985-01-01

    This book is an introduction on fluid mechanics incorporating computer applications. Topics covered are as follows: brief history; what is a fluid; two classes of fluids: liquids and gases; the continuum model of a fluid; methods of analyzing fluid flows; important characteristics of fluids; fundamentals and equations of motion; fluid statics; dimensional analysis and the similarity principle; laminar internal flows; ideal flow; external laminar and channel flows; turbulent flow; compressible flow; fluid flow measurements

  13. The presence of dysplastic nevus remnants in malignant melanomas. A population-based study of 551 malignant melanomas.

    Science.gov (United States)

    Hastrup, N; Osterlind, A; Drzewiecki, K T; Hou-Jensen, K

    1991-08-01

    We examined 512 malignant melanomas, representing all newly diagnosed cutaneous malignant melanomas, excluding lentigo maligna melanomas, from the period October 1, 1982 to March 31, 1985 occurring in the region of eastern Denmark in patients aged 20-79 years for the presence of dysplastic nevus remnants. Criteria for the diagnosis of a dysplastic nevus remnant include all the following changes (a) lentiginous or epithelioid melanocyte hyperplasia, (b) cytologic melanocyte atypia, (c) eosinophilic fibroplasia, (d) lamellar fibroplasia, and (e) lymphocytic infiltration in the dermis. Dysplastic nevus remnants were found in association with 34 (7%) of the evaluable 512 malignant melanomas. Fourteen (41%) of the remnants were of compound nevus type. In nine (27%) of the remnants, atypia was pronounced. Most (62%) dysplastic nevus remnants were contiguous to thin superficial spreading melanomas. We conclude from this population-based study that about 7% of malignant melanomas arise in prior dysplastic nevi.

  14. Disappearing fluid?

    International Nuclear Information System (INIS)

    Graney, K.; Chu, J.; Lin, P.C.

    2002-01-01

    Full text: A 78-year old male in end stage renal failure (ESRF) with a background of NIDDM retinopathy, nephropathy, and undergoing continuous ambulatory peritoneal dialysis (CAPD) presented with anorexia, clinically unwell, decreased mobility and right scrotal swelling. There was no difficulty during CAPD exchange except there was a positive fluid balance Peritoneal dialysates remained clear A CAPD peritoneal study was requested. 100Mbq 99mTc Sulphur Colloid was injected into a standard dialysate bag containing dialysate. Anterior dynamic images were acquired over the abdomen pelvis while the dialysate was infused Static images with anatomical markers were performed 20 mins post infusion, before and after patient ambulation and then after drainage. The study demonstrated communication between the peritoneal cavity and the right scrotal sac. Patient underwent right inguinal herniaplasty with a marlex mesh. A repeat CAPD flow study was performed as follow up and no abnormal connection between the peritoneal cavity and the right scrotal sac was demonstrated post operatively. This case study shows that CAPD flow studies can be undertaken as a simple, minimally invasive method to evaluate abnormal peritoneal fluid flow dynamics in patients undergoing CAPD, and have an impact on dialysis management. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  15. Auxillary Fluid Flowmeter

    DEFF Research Database (Denmark)

    RezaNejad Gatabi, Javad; Forouzbakhsh, Farshid; Ebrahimi Darkhaneh, Hadi

    2010-01-01

    The Auxiliary Fluid Flow meter is proposed to measure the fluid flow of any kind in both pipes and open channels. In this kind of flow measurement, the flow of an auxiliary fluid is measured Instead of direct measurement of the main fluid flow. The auxiliary fluid is injected into the main fluid ...

  16. THE ABSENCE OF EX-COMPANIONS IN TYPE Ia SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Di Stefano, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kilic, Mukremin, E-mail: rd@cfa.harvard.edu, E-mail: kilic@ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States)

    2012-11-01

    Type Ia supernovae (SNe Ia) play important roles in our study of the expansion and acceleration of the universe, but because we do not know the exact nature or natures of the progenitors, there is a systematic uncertainty that must be resolved if SNe Ia are to become more precise cosmic probes. No progenitor system has ever been identified either in the pre- or post-explosion images of a Ia event. There have been recent claims for and against the detection of ex-companion stars in several SNe Ia remnants. These studies, however, usually ignore the angular momentum gain of the progenitor white dwarf (WD), which leads to a spin-up phase and a subsequent spin-down phase before explosion. For spin-down timescales greater than 10{sup 5} years, the donor star could be too dim to detect by the time of explosion. Here we revisit the current limits on ex-companion stars to SNR 0509-67.5, a 400-year-old remnant in the Large Magellanic Cloud. If the effects of possible angular momentum gain on the WD are included, a wide range of single-degenerate progenitor models are allowed for this remnant. We demonstrate that the current absence of evidence for ex-companion stars in this remnant, as well as other SNe Ia remnants, does not necessarily provide the evidence of absence for ex-companions. We discuss potential ways to identify such ex-companion stars through deep imaging observations.

  17. THE ABSENCE OF EX-COMPANIONS IN TYPE Ia SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Di Stefano, R.; Kilic, Mukremin

    2012-01-01

    Type Ia supernovae (SNe Ia) play important roles in our study of the expansion and acceleration of the universe, but because we do not know the exact nature or natures of the progenitors, there is a systematic uncertainty that must be resolved if SNe Ia are to become more precise cosmic probes. No progenitor system has ever been identified either in the pre- or post-explosion images of a Ia event. There have been recent claims for and against the detection of ex-companion stars in several SNe Ia remnants. These studies, however, usually ignore the angular momentum gain of the progenitor white dwarf (WD), which leads to a spin-up phase and a subsequent spin-down phase before explosion. For spin-down timescales greater than 10 5 years, the donor star could be too dim to detect by the time of explosion. Here we revisit the current limits on ex-companion stars to SNR 0509-67.5, a 400-year-old remnant in the Large Magellanic Cloud. If the effects of possible angular momentum gain on the WD are included, a wide range of single-degenerate progenitor models are allowed for this remnant. We demonstrate that the current absence of evidence for ex-companion stars in this remnant, as well as other SNe Ia remnants, does not necessarily provide the evidence of absence for ex-companions. We discuss potential ways to identify such ex-companion stars through deep imaging observations.

  18. Hot gas in the interstellar medium, from supernova remnants to the diffuse coronal phase

    International Nuclear Information System (INIS)

    Ballet, Jean

    1988-01-01

    This research thesis addresses the study of the hot interstellar medium and of its main component, supernovae remnants. The author studied the hypothesis according to which ions observed in the interstellar medium are produced during the evaporation of cold clouds in the coronal phase. He shows that effects of ionisation delay are important and modify by a factor 10 the total quantity of ions predicted by the model. The study of the influence on ionisation of hot electrons penetrating cold layers revealed that this effect is rather weak. Then, based on the observation of the Kepler supernovae remnants by means of EXOSAT, and on the use of a hydrodynamics code coupled with a step-by-step calculation of ionisation of elements, the author studied the evolution of young supernovae remnants: propagation of the main shock in the interstellar medium, and of the backlash in the matter ejected by the star. The author also studied the X emission of an older supernovae remnant (the Cygnus Loop) by analysing three EXOSAT observations of this remnant. Results of Fabry-Perot spectrophotometry have been used to study optic lines [fr

  19. The role of small woodland remnants on ground dwelling insect conservation in Chaco Serrano, Central Argentina.

    Science.gov (United States)

    Moreno, María Laura; Fernández, María Guadalupe; Molina, Silvia Itati; Valladares, Graciela

    2013-01-01

    Many terrestrial ecosystems are changing due to extensive land use and habitat fragmentation, posing a major threat to biodiversity. In this study, the effects of patch size, isolation, and edge/interior localization on the ground dwelling insect communities in the Chaco Serrano woodland remnants in central Argentina were examined. Sampling was carried out in December 2003 and March 2004 in nine remnants (0.57 to 1000 hectares) using pitfall traps. In total, 7071 individuals representing 12 orders and 79 families were recorded. The taxonomic composition of these communities was linked to remnant size. Insect abundance increased (as did their richness, albeit marginally) as remnant area decreased, with no significant effects of isolation or edge/interior localization on abundance, richness, or diversity. No differential area effects were observed when abundance and richness of predators, scavengers, and herbivores were compared. Thus, ground insect communities in fragmented Chaco Serrano seem to respond mainly to patch level, rather than to within-patch (edge effects) or landscape (isolation) level variables. These results suggest that small Chaco Serrano remnants, by supporting larger ground-dwelling insect assemblages, may play an important role from a conservation viewpoint.

  20. Entirely Laparoscopic Gastrectomy and Colectomy for Remnant Gastric Cancer with Gastric Outlet Obstruction and Transverse Colon Invasion

    OpenAIRE

    Kim, Hyun Il; Kim, Min Gyu

    2015-01-01

    It is well known that gastrectomy with curative intent is the best way to improve outcomes of patients with remnant gastric cancer. Recently,several investigators reported their experiences with laparoscopic gastrectomy of remnant gastric cancer. We report the case of an 83-year-old female patient who was diagnosed with remnant gastric cancer with obstruction. She underwent an entirely laparoscopic distal gastrectomy with colectomy because of direct invasion of the transverse colon. The opera...

  1. Smart membranes for nitrate removal, water purification, and selective ion transportation

    Science.gov (United States)

    Wilson, William D [Pleasanton, CA; Schaldach, Charlene M [Pleasanton, CA; Bourcier, William L [Livermore, CA; Paul, Phillip H [Livermore, CA

    2009-12-15

    A computer designed nanoengineered membrane for separation of dissolved species. One embodiment provides an apparatus for treatment of a fluid that includes ions comprising a microengineered porous membrane, a system for producing an electrical charge across the membrane, and a series of nanopores extending through the membrane. The nanopores have a pore size such that when the fluid contacts the membrane, the nanopores will be in a condition of double layer overlap and allow passage only of ions opposite to the electrical charge across the membrane.

  2. Gyroelastic fluids

    Energy Technology Data Exchange (ETDEWEB)

    Kerbel, G.D.

    1981-01-20

    A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch.

  3. Gyroelastic fluids

    International Nuclear Information System (INIS)

    Kerbel, G.D.

    1981-01-01

    A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch

  4. Olive oil increases the magnitude of postprandial chylomicron remnants compared to milk fat and safflower oil.

    Science.gov (United States)

    Higashi, K; Ishikawa, T; Shige, H; Tomiyasu, K; Yoshida, H; Ito, T; Nakajima, K; Yonemura, A; Sawada, S; Nakamura, H

    1997-10-01

    The acute effects of olive oil, milk fat and safflower oil on postprandial lipemia and remnant lipoprotein metabolism were investigated. Eight Healthy male volunteers randomly underwent three types of oral fat-vitamin A loading tests. The test drink was a mixture of retinyl palmitate (RP)(50,000 IU of aqueous vitamin A/m2 body surface area) and one of the three types of oils (40 g of fat/m2 body surface area): olive oil (70.7% oleic acid of total fatty acids); milk fat (69.3% saturated fatty acid); safflower oil (74.2% linoleic acid). Olive oil significantly increased plasma triacylglycerol and RP concentrations 4 hours after fat loading, as compared to other fats. Increases of remnant like particle concentrations were higher after olive oil than after the other two fats. These results show that olive oil increases the magnitude of postprandial chylomicrons and chylomicron remnants compared to milk fat and safflower oil.

  5. Three cases of laparoscopic total gastrectomy with intracorporeal esophagojejunostomy for gastric cancer in remnant stomach.

    Science.gov (United States)

    Pan, Yu; Mou, Yi-Ping; Chen, Ke; Xu, Xiao-Wu; Cai, Jia-Qin; Wu, Di; Zhou, Yu-Cheng

    2014-11-13

    Gastric cancer in remnant stomach is a rare tumor but with poor prognosis. Compared with conventional open surgery, laparoscopic gastrectomy has potential benefits for these patients due to advantages resulting from its minimally invasive approach. Herein, we report on three patients with gastric cancer in remnant stomach who underwent laparoscopic total gastrectomy with intracorporeal esophagojejunostomy successfully. The operative time was 280, 250 and 225 minutes, the estimated blood loss was 100, 80 and 50 ml and the length of postoperative hospital stay was seven, eight and nine days respectively. Our experience has suggested that laparoscopic total gastrectomy with intracorporeal esophagojejunostomy can be a safe, feasible and promising option for patients with gastric cancer in remnant stomach.

  6. Optical pulsations in the Large Magellanic Cloud remnant 0540-69.3

    International Nuclear Information System (INIS)

    Middleditch, J.; Pennypacker, C.

    1985-01-01

    The X-ray pulsar PSR0540-693 was discovered in the Large Magellanic Cloud (LMC) supernova remnant, 0540-69.3, as a pulse, with repetition period approx. 50 ms, in Einstein Observatory data. Previous workers had noted that this remnant resembles the Crab Nebula because of the X-ray power law spectrum and suggested that the nebular emission was synchrotron radiation powered by a central pulsar. After the announcement of X-ray pulsed emission, other workers measured the broad optical band properties of the nebula and found evidence for synchrotron emission; and reported that the 4.5-arc s continuum emission remnant has only a tenth of the luminosity of the Crab Nebula. The authors have now detected pulsed optical emission for the X-ray pulsar, having a time-averaged magnitude of approx. 22.7. (author)

  7. Gravitational waves from remnant massive neutron stars of binary neutron star merger: Viscous hydrodynamics effects

    Science.gov (United States)

    Shibata, Masaru; Kiuchi, Kenta

    2017-06-01

    Employing a simplified version of the Israel-Stewart formalism of general-relativistic shear-viscous hydrodynamics, we explore the evolution of a remnant massive neutron star of binary neutron star merger and pay special attention to the resulting gravitational waveforms. We find that for the plausible values of the so-called viscous alpha parameter of the order 10-2 the degree of the differential rotation in the remnant massive neutron star is significantly reduced in the viscous time scale, ≲5 ms . Associated with this, the degree of nonaxisymmetric deformation is also reduced quickly, and as a consequence, the amplitude of quasiperiodic gravitational waves emitted also decays in the viscous time scale. Our results indicate that for modeling the evolution of the merger remnants of binary neutron stars we would have to take into account magnetohydrodynamics effects, which in nature could provide the viscous effects.

  8. Soft X-ray observations of the supernova remnants HB 3 and 3C 58

    Science.gov (United States)

    Galas, C. M. F.; Tuohy, I. R.; Garmire, G. P.

    1980-01-01

    The HEAO 1 A-2 low energy detectors have discovered soft X-ray emission from a source positionally coincident with the supernova remnant HB 3. The flux in the energy range 0.3-2.2 keV is about 6 x 10 to the -11th ergs per sq cm s. The spectral data are fitted to a hydrogen thermal bremsstrahlung model, and the physical parameters of the supernova remnant are estimated. The age derived is about 21,000 years, and the initial blast energy is about 3.1 x 10 to the 50th ergs. Upper limits to the soft X-ray flux and the luminosity of the supernova remnant 3 C 58 are also derived.

  9. Protocol for thyroid remnant ablation after recombinant TSH in thyroid carcinoma

    International Nuclear Information System (INIS)

    Pitoia, F.; Salvai, M.E.; Niepomniszcze, H.; Tamer, E. El

    2009-01-01

    In some countries, in order to perform rhTSH-aided thyroid remnant ablation (TRA) after surgery, it is generally necessary to confirm that thyroidectomy has been almost complete. Otherwise, the nuclear medicine specialist will not administer a high radioiodine dose because it might be hazardous due to the possibility of thyroid remnant actinic thyroiditis. Considering this, it would be necessary to use two rhTSH kits (one for diagnostic purposes and the other one to administer the 131 I dose). In this study, we used an alternative protocol for TRA with the use of one kit of rhTSH in twenty patients diagnosed with low risk papillary thyroid carcinoma. All patients had negative titers of anti-thyroglobulin antibodies. Successful thyroid remnant ablation was confirmed with an undetectable rhTSH stimulated thyroglobulin level ( [es

  10. Agricultural intensification exacerbates spillover effects on soil biogeochemistry in adjacent forest remnants.

    Directory of Open Access Journals (Sweden)

    Raphael K Didham

    Full Text Available Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could 'spare' further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only natural habitats that can be spared are fragments within landscapes dominated by agriculture. Therefore, land-sparing arguments hinge on land-use intensification having low spillover effects into adjacent protected areas, otherwise net conservation gains will diminish with increasing intensification. We test, for the first time, whether the degree of spillover from farmland into adjacent natural habitats scales in magnitude with increasing land-use intensity. We identified a continuous land-use intensity gradient across pastoral farming systems in New Zealand (based on 13 components of farmer input and soil biogeochemistry variables, and measured cumulative off-site spillover effects of fertilisers and livestock on soil biogeochemistry in 21 adjacent forest remnants. Ten of 11 measured soil properties differed significantly between remnants and intact-forest reference sites, for both fenced and unfenced remnants, at both edge and interior. For seven variables, the magnitude of effects scaled significantly with magnitude of surrounding land-use intensity, through complex interactions with fencing and edge effects. In particular, total C, total N, δ15N, total P and heavy-metal contaminants of phosphate fertilizers (Cd and U increased significantly within remnants in response to increasing land-use intensity, and these effects were exacerbated in unfenced relative to fenced remnants. This suggests movement of livestock into surrounding natural habitats is a significant component of agricultural spillover, but pervasive changes in soil biogeochemistry still occur through nutrient spillover channels alone

  11. The influence of massive black hole binaries on the morphology of merger remnants

    Science.gov (United States)

    Bortolas, E.; Gualandris, A.; Dotti, M.; Read, J. I.

    2018-06-01

    Massive black hole (MBH) binaries, formed as a result of galaxy mergers, are expected to harden by dynamical friction and three-body stellar scatterings, until emission of gravitational waves (GWs) leads to their final coalescence. According to recent simulations, MBH binaries can efficiently harden via stellar encounters only when the host geometry is triaxial, even if only modestly, as angular momentum diffusion allows an efficient repopulation of the binary loss cone. In this paper, we carry out a suite of N-body simulations of equal-mass galaxy collisions, varying the initial orbits and density profiles for the merging galaxies and running simulations both with and without central MBHs. We find that the presence of an MBH binary in the remnant makes the system nearly oblate, aligned with the galaxy merger plane, within a radius enclosing 100 MBH masses. We never find binary hosts to be prolate on any scale. The decaying MBHs slightly enhance the tangential anisotropy in the centre of the remnant due to angular momentum injection and the slingshot ejection of stars on nearly radial orbits. This latter effect results in about 1 per cent of the remnant stars being expelled from the galactic nucleus. Finally, we do not find any strong connection between the remnant morphology and the binary hardening rate, which depends only on the inner density slope of the remnant galaxy. Our results suggest that MBH binaries are able to coalesce within a few Gyr, even if the binary is found to partially erase the merger-induced triaxiality from the remnant.

  12. Mergers in galaxy groups. I. Structure and properties of elliptical remnants

    International Nuclear Information System (INIS)

    Taranu, Dan S.; Dubinski, John; Yee, H. K. C.

    2013-01-01

    We present collisionless simulations of dry mergers in groups of 3 to 25 galaxies to test the hypothesis that elliptical galaxies form at the centers of such groups. Mock observations of the central remnants confirm their similarity to ellipticals, despite having no dissipational component. We vary the profile of the original spiral's bulge and find that ellipticals formed from spirals with exponential bulges have too low Sersic indices. Mergers of spirals with de Vaucouleurs (classical) bulges produce remnants with larger Sersic indices correlated with luminosity, as with Sloan Digital Sky Survey ellipticals. Exponential bulge mergers are better fits to faint ellipticals, whereas classical bulge mergers better match luminous ellipticals. Similarly, luminous ellipticals are better reproduced by remnants undergoing many (>5) mergers, and fainter ellipticals by those with fewer mergers. The remnants follow tight size-luminosity and velocity dispersion-luminosity (Faber-Jackson) relations (<0.12 dex scatter), demonstrating that stochastic merging can produce tight scaling relations if the merging galaxies also follow tight scaling relations. The slopes of the size-luminosity and Faber-Jackson relations are close to observations but slightly shallower in the former case. Both relations' intercepts are offset—remnants are too large but have too low dispersions at fixed luminosity. Some remnants show substantial (v/σ > 0.1) rotational support, although most are slow rotators and few are very fast rotators (v/σ > 0.5). These findings contrast with previous studies concluding that dissipation is necessary to produce ellipticals from binary mergers of spirals. Multiple, mostly minor and dry mergers can produce bright ellipticals, whereas significant dissipation could be required to produce faint, rapidly rotating ellipticals.

  13. X-ray emission of the hot gas and of accelerated particles in supernova remnants

    International Nuclear Information System (INIS)

    Acero, F.

    2008-09-01

    The current observations seem to support the theory that the shock wave of supernova remnants accelerate electrons (representing about 1% of cosmic rays) of the interstellar medium up to energies of about 10 15 eV. However there is still no solid evidence that supernova remnants also accelerate protons (major component of cosmic rays). The X-ray observations of those supernova remnants with the satellite XMM-Newton can provide crucial information on the acceleration mechanisms and on this population of accelerated particles. This thesis presents the X-ray analysis of the supernova remnants RX J1713.7-3946 and SN 1006 for which it has been shown that they accelerate electrons efficiently. As a result, these objects are very good targets to compare the theoretical models of acceleration to the observation. For the first object, I constructed through new XMM-Newton observations, the first high-angular resolution mosaic of the entire supernova remnant. I then compared the X- and gamma-ray emission of this object in order to understand the nature of the gamma-ray emission. This spectral and morphological comparison allowed me to discuss the two possible origins of the gamma-ray radiation (issued by electrons or by protons). For SN 1006, I studied the density of the ambient medium in which the shock wave propagates. This density is a key parameter for the hydrodynamical evolution of the remnant and for studying a future gamma-ray emission. The study of X-ray emission of the gas heated by the shock wave allowed me to better estimate of the value of the density so far poorly constrained for this object. (author)

  14. Simplified Aeroelastic Model for Fluid Structure Interaction between Microcantilever Sensors and Fluid Surroundings.

    Directory of Open Access Journals (Sweden)

    Fei Wang

    Full Text Available Fluid-structural coupling occurs when microcantilever sensors vibrate in a fluid. Due to the complexity of the mechanical characteristics of microcantilevers and lack of high-precision microscopic mechanical testing instruments, effective methods for studying the fluid-structural coupling of microcantilevers are lacking, especially for non-rectangular microcantilevers. Here, we report fluid-structure interactions (FSI of the cable-membrane structure via a macroscopic study. The simplified aeroelastic model was introduced into the microscopic field to establish a fluid-structure coupling vibration model for microcantilever sensors. We used the finite element method to solve the coupled FSI system. Based on the simplified aeroelastic model, simulation analysis of the effects of the air environment on the vibration of the commonly used rectangular microcantilever was also performed. The obtained results are consistent with the literature. The proposed model can also be applied to the auxiliary design of rectangular and non-rectangular sensors used in fluid environments.

  15. Effective tension and fluctuations in active membranes

    OpenAIRE

    Loubet, Bastien; Seifert, Udo; Lomholt, Michael Andersen

    2011-01-01

    We calculate the fluctuation spectrum of the shape of a lipid vesicle or cell exposed to a nonthermal source of noise. In particular we take into account constraints on the membrane area and the volume of fluid that it encapsulates when obtaining expressions for the dependency of the membrane tension on the noise. We then investigate three possible origins of the non-thermal noise taken from the literature: A direct force, which models an external medium pushing on the membrane. A curvature f...

  16. Microbiological quality of some brands of intravenous fluids ...

    African Journals Online (AJOL)

    Microbiological quality of some brands of intravenous fluids produced by some pharmaceutical companies in Nigeria was investigated. Membrane filtration method was used for concentration of contaminating organisms in the intravenous fluids. Thioglycollate medium, Tryptone Soya broth, Brilliant Green Agar ...

  17. Geonic black holes and remnants in Eddington-inspired Born-Infeld gravity.

    Science.gov (United States)

    Olmo, Gonzalo J; Rubiera-Garcia, D; Sanchis-Alepuz, Helios

    We show that electrically charged solutions within the Eddington-inspired Born-Infeld theory of gravity replace the central singularity by a wormhole supported by the electric field. As a result, the total energy associated with the electric field is finite and similar to that found in the Born-Infeld electromagnetic theory. When a certain charge-to-mass ratio is satisfied, in the lowest part of the mass and charge spectrum the event horizon disappears, yielding stable remnants. We argue that quantum effects in the matter sector can lower the mass of these remnants from the Planck scale down to the TeV scale.

  18. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

    International Nuclear Information System (INIS)

    Beck, R.; Drury, L.O.; Voelk, H.J.; Bogdan, T.J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium

  19. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

    Science.gov (United States)

    Beck, R.; Drury, L. O.; Voelk, H. J.; Bogdan, T. J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium.

  20. Nano- and microparticles at fluid and biological interfaces

    Science.gov (United States)

    Dasgupta, S.; Auth, T.; Gompper, G.

    2017-09-01

    Systems with interfaces are abundant in both technological applications and biology. While a fluid interface separates two fluids, membranes separate the inside of vesicles from the outside, the interior of biological cells from the environment, and compartmentalize cells into organelles. The physical properties of interfaces are characterized by interface tension, those of membranes are characterized by bending and stretching elasticity. Amphiphilic molecules like surfactants that are added to a system with two immiscible fluids decrease the interface tension and induce a bending rigidity. Lipid bilayer membranes of vesicles can be stretched or compressed by osmotic pressure; in biological cells, also the presence of a cytoskeleton can induce membrane tension. If the thickness of the interface or the membrane is small compared with its lateral extension, both can be described using two-dimensional mathematical surfaces embedded in three-dimensional space. We review recent work on the interaction of particles with interfaces and membranes. This can be micrometer-sized particles at interfaces that stabilise emulsions or form colloidosomes, as well as typically nanometer-sized particles at membranes, such as viruses, parasites, and engineered drug delivery systems. In both cases, we first discuss the interaction of single particles with interfaces and membranes, e.g. particles in external fields, non-spherical particles, and particles at curved interfaces, followed by interface-mediated interaction between two particles, many-particle interactions, interface and membrane curvature-induced phenomena, and applications.

  1. Peripheral Protein Unfolding Drives Membrane Bending.

    Science.gov (United States)

    Siaw, Hew Ming Helen; Raghunath, Gokul; Dyer, R Brian

    2018-06-20

    Dynamic modulation of lipid membrane curvature can be achieved by a number of peripheral protein binding mechanisms such as hy-drophobic insertion of amphipathic helices and membrane scaffolding. Recently, an alternative mechanism was proposed in which crowding of peripherally bound proteins induces membrane curvature through steric pressure generated by lateral collisions. This effect was enhanced using intrinsically disordered proteins that possess high hydrodynamic radii, prompting us to explore whether membrane bending can be triggered by the folding-unfolding transition of surface-bound proteins. We utilized histidine-tagged human serum albumin bound to Ni-NTA-DGS containing liposomes as our model system to test this hypothesis. We found that reduction of the disulfide bonds in the protein resulted in unfolding of HSA, which subsequently led to membrane tubule formation. The frequency of tubule formation was found to be significantly higher when the proteins were unfolded while being localized to a phase-separated domain as opposed to randomly distributed in fluid phase liposomes, indicating that the steric pressure generated from protein unfolding is directly responsible for membrane deformation. Our results are critical for the design of peripheral membrane protein-immobilization strategies and open new avenues for exploring mechanisms of membrane bending driven by conformational changes of peripheral membrane proteins.

  2. Microfluidic device and methods for focusing fluid streams using electroosmotically induced pressures

    Science.gov (United States)

    Jacobson, Stephen C.; Ramsey, J. Michael

    2010-06-01

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either electric current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to electrokinetically inducing fluid flow to confine a selected material in a region of a microchannel that is not influenced by an electric field. Other structures for inducing fluid flow in accordance with this invention include nanochannel bridging membranes and alternating current fluid pumping devices. Applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  3. Membranes for nanometer-scale mass fast transport

    Science.gov (United States)

    Bakajin, Olgica [San Leandro, CA; Holt, Jason [Berkeley, CA; Noy, Aleksandr [Belmont, CA; Park, Hyung Gyu [Oakland, CA

    2011-10-18

    Nanoporous membranes comprising single walled, double walled, and multiwalled carbon nanotubes embedded in a matrix material were fabricated for fluid mechanics and mass transfer studies on the nanometer scale and commercial applications. Average pore size can be 2 nm to 20 nm, or seven nm or less, or two nanometers or less. The membrane can be free of large voids spanning the membrane such that transport of material such as gas or liquid occurs exclusively through the tubes. Fast fluid, vapor, and liquid transport are observed. Versatile micromachining methods can be used for membrane fabrication. A single chip can comprise multiple membranes. These membranes are a robust platform for the study of confined molecular transport, with applications in liquid and gas separations and chemical sensing including desalination, dialysis, and fabric formation.

  4. Dynamics of Biomembranes: Effect of the Bulk Fluid

    KAUST Repository

    Bonito, A.

    2011-01-01

    We derive a biomembrane model consisting of a fluid enclosed by a lipid membrane. The membrane is characterized by its Canham-Helfrich energy (Willmore energy with area constraint) and acts as a boundary force on the Navier-Stokes system modeling an incompressible fluid. We give a concise description of the model and of the associated numerical scheme. We provide numerical simulations with emphasis on the comparisons between different types of flow: the geometric model which does not take into account the bulk fluid and the biomembrane model for two different regimes of parameters. © EDP Sciences, 2011.

  5. EXOTIC PLANTS IN THE CIBODAS BOTANIC GARDENS REMNANT FOREST: INVENTORY AND CLUSTER ANALYSIS OF SEVERAL ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    Decky Indrawan Junaedi

    2014-01-01

    Full Text Available Due to potential impact of invasive alien (exotic species to the natural ecosystems, inventory of exotic species in the Cibodas Botanic Gardens (CBG remnant forest area is an urgent need for CBG. Inventory of exotic species can assist gardens manager to set priorities and plan better responses for possible or existed invasive plants in the CBG remnants forest. The objectives of this study are to do inventory of the exotic species in the CBG remnant forest and to determine whether several environmental variables play role to the existence of exotic species in the CBG remnant forests. There are 26 exotic plant species (23 genera, 14 families found and recorded from all four remnant forests in CBG. Cluster analysis of four environmental variables shows that clustering of environmental factors of exotic species correlates with the abundances of those exotic species. The relation between environmental factor clusters and the abundance of those exotics signify the role of environmental variables on the existence of exotic plant species. The information of exotic plant species in the remnants forest is the base information for gardens manager to manage exotic species in CBG remnants forest. The relation of several environmental factors with exotic species abundance could assist gardens manager to understand better the supportive and or suppressor factors of exotics in the CBG remnants forest. Further study on these species is needed to set priorities to decide which species should be treated first in order to minimize the impact of exotic plant species to native ecosystem of CBG.

  6. EXOTIC PLANTS IN THE CIBODAS BOTANIC GARDENS REMNANT FOREST: INVENTORY AND CLUSTER ANALYSIS OF SEVERAL ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    Decky Indrawan Junaedi

    2014-01-01

    Full Text Available Due to potential impact of invasive alien (exotic species to the natural ecosystems, inventory of exotic species in the Cibodas Botanic Gardens (CBG remnant forest area is an urgent need for CBG. Inventory of exotic species can assist gardens manager to set priorities and plan better responses for possible or existed invasive plants in the CBG remnants forest. The objectives of this study are to do inventory of the exotic species in the CBG remnant forest and to determine whether several environmental variables play role to the existence of exotic species in the CBG remnant forests. There are 26 exotic plant species  (23 genera, 14 families found and recorded from all four remnant forests in CBG. Cluster analysis of four environmental variables shows that clustering of environmental factors of exotic species correlates with the abundances of those exotic species. The relation between environmental factor clusters and the abundance of those exotics signify the role of environmental variables on the existence of exotic plant species. The information of exotic plant species in the remnants forest is the base information for gardens manager to manage exotic species in CBG remnants forest. The relation of several environmental factors with exotic species abundance could assist gardens manager to understand better the supportive and or suppressor factors of exotics in the CBG remnants forest. Further study on these species is needed to set priorities to decide which species should be treated first in order to minimize the impact of exotic plant species to native ecosystem of CBG.

  7. Diagnosis of foetal membrane ruptures: Placental alpha ...

    African Journals Online (AJOL)

    Context: Pre‑labour rupture of membranes (PROM) is a common obstetric complication which presents a diagnostic challenge, especially in equivocal ... problematic with the need to balance the risk of prematurity with that of prolonged ... array of rapid, minimally invasive tests based on biochemical markers in amniotic fluid ...

  8. Ceramic oxygen transport membrane array reactor and reforming method

    Science.gov (United States)

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

    2017-10-03

    The invention relates to a commercially viable modular ceramic oxygen transport membrane system for utilizing heat generated in reactively-driven oxygen transport membrane tubes to generate steam, heat process fluid and/or provide energy to carry out endothermic chemical reactions. The system provides for improved thermal coupling of oxygen transport membrane tubes to steam generation tubes or process heater tubes or reactor tubes for efficient and effective radiant heat transfer.

  9. Mechanics of nonplanar membranes with force-dipole activity

    DEFF Research Database (Denmark)

    Lomholt, Michael Andersen

    2006-01-01

    A study is made of how active membrane proteins can modify the long wavelength mechanics of fluid membranes. The activity of the proteins is modelled as disturbing the protein surroundings through nonlocal force distributions of which a force-dipole distribution is the simplest example. An analytic...... contributions to mechanical properties such as tension and bending moments become apparent. It is also explained how the activity can induce a hydrodynamic attraction between the active proteins in the membrane....

  10. Clinical relevance of non-fasting and postprandial hypertriglyceridemia and remnant cholesterol

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G; Freiberg, Jacob J

    2011-01-01

    Non-fasting triglycerides are measured at any time within up to 8 h (14 h) after any normal meal, while postprandial triglycerides are measured at a fixed time point within up to 8 h (14 h) of a standardised fat tolerance test. The simplest possible way of evaluating remnant cholesterol is non......-fasting/postprandial total cholesterol minus low-density lipoprotein (LDL) cholesterol minus high-density lipoprotein (HDL) cholesterol. Elevated levels of non-fasting/postprandial triglycerides directly correlate with elevated remnant cholesterol. In the general population, 38% of men have non......-fasting/postprandial triglycerides > 2mmol/L (>176 mg/dL) while 45% of men have non-fasting/postprandial triglyceride levels of 1-2 mmol/L (89-176 mg/dL); corresponding fractions in women are 20% and 47%. Also, 31% of men have remnant cholesterol levels > 1mmol/L (>39 mg/dL) while 46% of men have remnant cholesterol levels of 0...

  11. AN X-RAY INVESTIGATION OF THREE SUPERNOVA REMNANTS IN THE LARGE MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Klimek, Matthew D.; Points, S. D.; Smith, R. C.; Shelton, R. L.; Williams, R.

    2010-01-01

    We have investigated three supernova remnants (SNRs) in the LMC using multi-wavelength data. These SNRs are generally fainter than the known sample (see Section 4) and may represent a previously missed population. One of our SNRs is the second LMC remnant analyzed which is larger than any Galactic remnant for which a definite size has been established. The analysis of such a large remnant contributes to the understanding of the population of highly evolved SNRs. We have obtained X-ray images and spectra of three of these recently identified SNRs using the XMM-Newton observatory. These data, in conjunction with pre-existing optical emission-line images and spectra, were used to determine the physical conditions of the optical- and X-ray-emitting gas in the SNRs. We have compared the morphologies of the SNRs in the different wavebands. The physical properties of the warm ionized shell were determined from the Hα surface brightness and the SNR expansion velocity. The X-ray spectra were fit with a thermal plasma model and the physical conditions of the hot gas were derived from the model fits. Finally, we have compared our observations with simulations of SNR evolution.

  12. Vocal cord paralysis following I-131 ablation of a postthyroidectomy remnant

    International Nuclear Information System (INIS)

    Lee, T.C.; Harbert, J.C.; Dejter, S.W.; Mariner, D.R.; VanDam, J.

    1985-01-01

    Vocal cord paralysis has been reported following I-131 therapy of thyrotoxicosis and following ablation of the whole thryoid. However, this rare complication has not previously been described following I-131 ablation of a postthyroidectomy remnant. The authors report a patient who required tracheostomy for bilateral vocal cord paralysis following I-131 ablation after near-total thyroidectomy for papillary thyroid carcinoma

  13. Case Report: CT diagnosis of thymic remnant cyst/thymopharyngeal duct cyst

    International Nuclear Information System (INIS)

    Daga, Bipin V; Chaudhary, VA; Dhamangaokar, VB

    2009-01-01

    A 4-year-old boy presented with history of left anterolateral neck swelling since birth. He was clinically diagnosed to have a branchial cleft cyst. A CT scan revealed findings suggestive of a thymic remnant cyst. The lesion was excised and the diagnosis was confirmed by histopathology

  14. Gamma-ray bursts from stellar remnants - Probing the universe at high redshift

    NARCIS (Netherlands)

    Wijers, R.A.M.J.; Bloom, J.S.; Bagla, J.S.; Natarajan, P.

    1998-01-01

    A gamma-ray burst (GRB) releases an amount of energy similar to that of a supernova explosion, which combined with its rapid variability suggests an origin related to neutron stars or black holes. Since these compact stellar remnants form from the most massive stars not long after their birth, GRBs

  15. HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

    International Nuclear Information System (INIS)

    Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

    2009-01-01

    The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 ± 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is α = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

  16. Numerical Simulations of Supernova Remnant Evolution in a Cloudy Interstellar Medium

    Energy Technology Data Exchange (ETDEWEB)

    Slavin, Jonathan D.; Smith, Randall K.; Foster, Adam; Winter, Henry D.; Raymond, John C.; Slane, Patrick O. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yamaguchi, Hiroya, E-mail: jslavin@cfa.harvard.edu [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2017-09-01

    The mixed morphology class of supernova remnants has centrally peaked X-ray emission along with a shell-like morphology in radio emission. White and Long proposed that these remnants are evolving in a cloudy medium wherein the clouds are evaporated via thermal conduction once being overrun by the expanding shock. Their analytical model made detailed predictions regarding temperature, density, and emission profiles as well as shock evolution. We present numerical hydrodynamical models in 2D and 3D including thermal conduction, testing the White and Long model and presenting results for the evolution and emission from remnants evolving in a cloudy medium. We find that, while certain general results of the White and Long model hold, such as the way the remnants expand and the flattening of the X-ray surface brightness distribution, in detail there are substantial differences. In particular we find that the X-ray luminosity is dominated by emission from shocked cloud gas early on, leading to a bright peak, which then declines and flattens as evaporation becomes more important. In addition, the effects of thermal conduction on the intercloud gas, which is not included in the White and Long model, are important and lead to further flattening of the X-ray brightness profile as well as lower X-ray emission temperatures.

  17. X-ray emission from reverse-shocked ejecta in supernova remnants

    Science.gov (United States)

    Cioffi, Denis F.; Mckee, Christopher F.

    1990-01-01

    A simple physical model of the dynamics of a young supernova remnant is used to derive a straightforward kinematical description of the reverse shock. With suitable approximations, formulae can then be developed to give the X-ray emission of the reverse-shocked ejecta. The results are found to agree favorably with observations of SN1006.

  18. Use of radionuclide techniques for assessment of splenic function and detection of splenic remnants

    International Nuclear Information System (INIS)

    Ganguly, S.; Sinha, S.; Sarkar, B.R.; Basu, S.; Ghosh, S.

    1998-01-01

    Full text: The spleen is often involved in hematological malignancies; it is also the site of RBC destruction in thalassemia and ITP. In latter cases, splenectomy is often performed and postoperatively, detection of functioning splenic remnants affect the prognosis adversely. In this study, we assessed the usefulness of radionuclide techniques in : a) assessment of splenic function in primarily non-splenic diseases (benign or malignant), and b) detection of splenic remnant after splenectomy. 12 patients of splenomegaly and 5 patients after splenectomy underwent splenic imaging; imaging was performed using both 99m Tc-sulphur colloid (with first pass) and 99m Tc labelled heat denatured RBCs as tracers. Thus splenic perfusion, morphology and RBC trapping functions were all assessed. The colloid images usually matched the RBC images except in 2 cases where photogenic areas (presumably infarcts) were visualized on RBC scans that were missed on colloid scans. Three of the post splenectomy cases revealed functioning splenic remnants, which was also better visualized on RBC scans. It is concluded that radionuclide imaging could be used regularly for assessing function of spleen, or detecting splenic remnants

  19. Clinical outcomes of endoscopic submucosal dissection for early gastric cancer in remnant stomach or gastric tube.

    Science.gov (United States)

    Nishide, N; Ono, H; Kakushima, N; Takizawa, K; Tanaka, M; Matsubayashi, H; Yamaguchi, Y

    2012-06-01

    Little information exists regarding the optimal treatment of early gastric cancer (EGC) in a remnant stomach or gastric tube. The aim of this study was to assess the feasibility and clinical outcomes of endoscopic submucosal dissection (ESD) for EGC in a remnant stomach and gastric tube. Between September 2002 and December 2009, ESD was performed in 62 lesions in 59 patients with EGC in a remnant stomach (48 lesions) or gastric tube (14 lesions). Clinicopathological data were retrieved retrospectively to assess the en bloc resection rate, complications, and outcomes. Treatment results were assessed according to the indications for endoscopic resection, and were compared with those of ESD performed in a whole stomach during the same study period. The en bloc resection rates for lesions within the standard and expanded indication were 100 % and 93 %, respectively. Postoperative bleeding occurred in five patients (8 %). The perforation rate was significantly higher (18 %, 11 /62) than that of ESD in a whole stomach (5 %, 69 /1479). Among the perforation cases, eight lesions involved the anastomotic site or stump line, and ulcerative changes were observed in five lesions. The 3-year overall survival rate was 85 %, with eight deaths due to other causes and no deaths from gastric cancer. A high en bloc resection rate was achieved by ESD for EGC in a remnant stomach or gastric tube; however, this procedure is still technically demanding due to the high complication rate of perforation. © Georg Thieme Verlag KG Stuttgart · New York.

  20. The influence of thermal pressure on equilibrium models of hypermassive neutron star merger remnants

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, J. D.; Ott, C. D.; Roberts, L. [TAPIR, California Institute of Technology, Mailcode 350-17, Pasadena, CA 91125 (United States); O' Connor, E. P. [CITA, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Kiuchi, K. [Yukawa Institute for Theoretical Physics, University of Kyoto, Kyoto (Japan); Duez, M., E-mail: cott@tapir.caltech.edu [Department of Physics and Astronomy, Washington State University, Pullman, WA (United States)

    2014-07-20

    The merger of two neutron stars leaves behind a rapidly spinning hypermassive object whose survival is believed to depend on the maximum mass supported by the nuclear equation of state (EOS), angular momentum redistribution by (magneto-)rotational instabilities, and spindown by gravitational waves. The high temperatures (∼5-40 MeV) prevailing in the merger remnant may provide thermal pressure support that could increase its maximum mass and, thus, its life on a neutrino-cooling timescale. We investigate the role of thermal pressure support in hypermassive merger remnants by computing sequences of spherically symmetric and axisymmetric uniformly and differentially rotating equilibrium solutions to the general-relativistic stellar structure equations. Using a set of finite-temperature nuclear EOS, we find that hot maximum-mass critically spinning configurations generally do not support larger baryonic masses than their cold counterparts. However, subcritically spinning configurations with mean density of less than a few times nuclear saturation density yield a significantly thermally enhanced mass. Even without decreasing the maximum mass, cooling and other forms of energy loss can drive the remnant to an unstable state. We infer secular instability by identifying approximate energy turning points in equilibrium sequences of constant baryonic mass parameterized by maximum density. Energy loss carries the remnant along the direction of decreasing gravitational mass and higher density until instability triggers collapse. Since configurations with more thermal pressure support are less compact and thus begin their evolution at a lower maximum density, they remain stable for longer periods after merger.

  1. The influence of thermal pressure on equilibrium models of hypermassive neutron star merger remnants

    International Nuclear Information System (INIS)

    Kaplan, J. D.; Ott, C. D.; Roberts, L.; O'Connor, E. P.; Kiuchi, K.; Duez, M.

    2014-01-01

    The merger of two neutron stars leaves behind a rapidly spinning hypermassive object whose survival is believed to depend on the maximum mass supported by the nuclear equation of state (EOS), angular momentum redistribution by (magneto-)rotational instabilities, and spindown by gravitational waves. The high temperatures (∼5-40 MeV) prevailing in the merger remnant may provide thermal pressure support that could increase its maximum mass and, thus, its life on a neutrino-cooling timescale. We investigate the role of thermal pressure support in hypermassive merger remnants by computing sequences of spherically symmetric and axisymmetric uniformly and differentially rotating equilibrium solutions to the general-relativistic stellar structure equations. Using a set of finite-temperature nuclear EOS, we find that hot maximum-mass critically spinning configurations generally do not support larger baryonic masses than their cold counterparts. However, subcritically spinning configurations with mean density of less than a few times nuclear saturation density yield a significantly thermally enhanced mass. Even without decreasing the maximum mass, cooling and other forms of energy loss can drive the remnant to an unstable state. We infer secular instability by identifying approximate energy turning points in equilibrium sequences of constant baryonic mass parameterized by maximum density. Energy loss carries the remnant along the direction of decreasing gravitational mass and higher density until instability triggers collapse. Since configurations with more thermal pressure support are less compact and thus begin their evolution at a lower maximum density, they remain stable for longer periods after merger.

  2. Effect of statin versus fibrate on postprandial endothelial dysfunction: role of remnant-like particles

    NARCIS (Netherlands)

    Wilmink, H. W.; Twickler, M. B.; Banga, J. D.; Dallinga-Thie, G. M.; Eeltink, H.; Erkelens, D. W.; Rabelink, T. J.; Stroes, E. S.

    2001-01-01

    BACKGROUND: Postprandial lipemia is associated with endothelial dysfunction. Remnant-like particles (RLP) have been suggested to contribute to these adverse vascular effects. We investigated the effect of cerivastatin and gemfibrozil upon oral fat load induced changes in endothelial function and

  3. Bat activity at remnant oak trees in California Central Coast vineyards

    Science.gov (United States)

    William D. Tietje; Ted Weller; Christopher C. Yim

    2015-01-01

    During 1990 to 2013, the area planted with wine grapes increased nearly 4.5 times in San Luis Obispo County. Much of this development occurred on open oak savanna with scattered oak (Quercus spp.) trees. Remnant trees are retained in some vineyards, but their value to biodiversity retention has not been quantified. During April to September 2014,...

  4. Effect of adhesive remnant removal on enamel topography after bracket debonding

    Directory of Open Access Journals (Sweden)

    Larissa Adrian Meira Cardoso

    2014-12-01

    Full Text Available INTRODUCTION: At orthodontic treatment completion, knowledge about the effects of adhesive remnant removal on enamel is paramount.OBJECTIVE: This study aimed at assessing the effect of different adhesive remnant removal methods on enamel topography (ESI and surface roughness (Ra after bracket debonding and polishing.METHODS: A total of 50 human premolars were selected and divided into five groups according to the method used for adhesive remnant removal: high speed tungsten carbide bur (TCB, Sof-Lex discs (SL, adhesive removing plier (PL, ultrasound (US and Fiberglass burs (FB. Metal brackets were bonded with Transbond XT, stored at 37oC for 24 hours before debonding with adhesive removing plier. Subsequently, removal methods were carried out followed by polishing with pumice paste. Qualitative and quantitative analyses were conducted with pre-bonding, post-debonding and post-polishing analyses. Results were submitted to statistical analysis with F test (ANOVA and Tukey's (Ra as well as with Kruskal-Wallis and Bonferroni tests (ESI (P < 0.05.RESULTS: US Ra and ESI were significantly greater than TCB, SL, PL and FB. Polishing minimized Ra and ESI in the SL and FB groups.CONCLUSION: Adhesive remnant removal with SL and FB associated with polishing are recommended due to causing little damage to the enamel.

  5. Energy Dependence of Synchrotron X-Ray Rims in Tycho's Supernova Remnant

    Science.gov (United States)

    Tran, Aaron; Williams, Brian J.; Petre, Robert; Ressler, Sean M.; Reynolds, Stephen P.

    2015-01-01

    Several young supernova remnants exhibit thin X-ray bright rims of synchrotron radiation at their forward shocks. Thin rims require strong magnetic field amplification beyond simple shock compression if rim widths are only limited by electron energy losses. But, magnetic field damping behind the shock could produce similarly thin rims with less extreme field amplification. Variation of rim width with energy may thus discriminate between competing influences on rim widths. We measured rim widths around Tycho's supernova remnant in 5 energy bands using an archival 750 ks Chandra observation. Rims narrow with increasing energy and are well described by either loss-limited or damped scenarios, so X-ray rim width-energy dependence does not uniquely specify a model. But, radio counterparts to thin rims are not loss-limited and better reflect magnetic field structure. Joint radio and X-ray modeling favors magnetic damping in Tycho's SNR with damping lengths approximately 1-5% of remnant radius and magnetic field strengths approximately 50-400 micron G assuming Bohm diffusion. X-ray rim widths are approximately 1% of remnant radius, somewhat smaller than inferred damping lengths. Electron energy losses are important in all models of X-ray rims, suggesting that the distinction between loss-limited and damped models is blurred in soft X-rays. All loss-limited and damping models require magnetic fields approximately greater than 20 micron G, arming the necessity of magnetic field amplification beyond simple compression.

  6. Supernova remnant S 147 and its associated neutron star(s)

    Science.gov (United States)

    Gvaramadze, V. V.

    2006-07-01

    The supernova remnant S 147 harbors the pulsar PSR J 0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J 0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic age. Our proposal implies that S 147 is the diffuse remnant of the second supernova explosion (that disrupted the binary system) and that a much younger second neutron star (not necessarily manifesting itself as a radio pulsar) should be associated with S 147. We use the existing observational data on the system to suggest that the progenitor of the supernova that formed S 147 was a Wolf-Rayet star (so that the supernova explosion occurred within a wind bubble surrounded by a massive shell) and to constrain the parameters of the binary system. We also restrict the magnitude and direction of the kick velocity received by the young neutron star at birth and find that the kick vector should not strongly deviate from the orbital plane of the binary system.

  7. The Derivation of Scandinavian Object Shift and Remnant VP-Topicalisation

    DEFF Research Database (Denmark)

    Engels, Eva; Vikner, Sten

    2013-01-01

    Based on the examination of remnant VP-topicalization constructions, this chapter argues for an order preservation analysis to Scandinavian Object Shift. Reviewing Fox and Pesetsky’s (2003, 2005) cyclic linearization approach and extending the empirical data base, we show that the phenomena are b...

  8. Lennard-Jones fluids in two-dimensional nano-pores. Multi-phase coexistence and fluid structure

    Science.gov (United States)

    Yatsyshin, Petr; Savva, Nikos; Kalliadasis, Serafim

    2014-03-01

    We present a number of fundamental findings on the wetting behaviour of nano-pores. A popular model for fluid confinement is a one-dimensional (1D) slit pore formed by two parallel planar walls and it exhibits capillary condensation (CC): a first-order phase transition from vapour to capillary-liquid (Kelvin shift). Capping such a pore at one end by a third orthogonal wall forms a prototypical two-dimensional (2D) pore. We show that 2D pores possess a wetting temperature such that below this temperature CC remains of first order, above it becomes a continuous phase transition manifested by a slab of capillary-liquid filling the pore from the capping wall. Continuous CC exhibits hysteresis and can be preceded by a first-order capillary prewetting transition. Additionally, liquid drops can form in the corners of the 2D pore (remnant of 2D wedge prewetting). The three fluid phases, vapour, capillary-liquid slab and corner drops, can coexist at the pore triple point. Our model is based on the statistical mechanics of fluids in the density functional formulation. The fluid-fluid and fluid-substrate interactions are dispersive. We analyze in detail the microscopic fluid structure, isotherms and full phase diagrams. Our findings also suggest novel ways to control wetting of nano-pores. We are grateful to the European Research Council via Advanced Grant No. 247031 for support.

  9. Synovial fluid analysis

    Science.gov (United States)

    Joint fluid analysis; Joint fluid aspiration ... El-Gabalawy HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of ...

  10. Appropriate fluid regimens to prevent bronchopulmonary dysplasia.

    Science.gov (United States)

    Tammela, O K

    1995-01-01

    Pulmonary oedema is an important problem in premature neonates with surfactant deficiency because of fluid accumulation in the lung interstitium and reduced urine output. Some retrospective reports suggest that excessive early hydration might increase the risk of bronchopulmonary dysplasia (BPD). Only three prospective studies evaluating low or conventional fluid administration regimens to very low birth weight infants have been published. According to their results no significant differences in the incidence of BPD have been shown. However, fluid restriction seems to improve the outcome of the infants because of decreased incidence of haemodynamically significant patent ductus arteriosus, necrotizing enterocolitis, pulmonary air leaks and decreased mortality. The appropriate amount of sodium in the intravenous fluids during the first days of life needs further evaluation. In tiny infants with birth weights from 500 to 800g intensive monitoring of fluid balance is essential to control the extremely high fluid losses due to evaporation. Undernutrition is a risk factor of BPD and therefore it is important to start parenteral nutrition early. The benefit of the use of colloids as volume expanders is controversial. According to some retrospective reports there might be an association with increased use of colloidal fluids during the first days of life and the development of BPD. Early excessive fluid administration might constitute a potential risk for low birth weight infants with hyaline membrane disease.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. MRI of subdural fluid collections in infants

    International Nuclear Information System (INIS)

    Fukushima, Tsuneyuki; Takagi, Takuji; Nagai, Hajime; Banno, Tatsuo

    1988-01-01

    Twenty cases of subdural fluid collectioin in infants were examined by MRI (0.5 Tesla). The findings of MRI were classified into 3 groups as follows: Group I: Blood component is observed in the entire subdural fluid (4 cases, 20 %). Group II: Blood component is observed in a part of the subdural fluid (4 cases, 20 %). Group III: Subdural fluid consists of pure CSF (12 cases, 60 %). In general, operative treatment should be considered for cases which have blood components in the subdural space and/or symptoms and signs of increased ICP. In group I, operation was performed on 2 cases (50 %). In group II, subdural fluid collections were associated with dilated subarachnoid spaces and 2 cases were operated on in this group (50 %). In group III, only one case was operated on (8.3 %) and subdural fluid collections disappeared spontaneously in 4 cases of this group. The precise anatomical location of subdural fluid collections could not be decided in several cases even by MRI. The cases which had blood components, tended to demonstrate membranes frequently on MRI. However, the existence of blood components did not affect the DQ S significantly. The prognosis of subdural fluid collection is supposedly related to the degree of preexistent brain damage. (author)

  12. 3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Shiu-Hang; Kamae, Tuneyoshi; Ellison, Donald C.

    2008-07-02

    We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or pion-decay from protons.

  13. The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers

    Science.gov (United States)

    Khazendar, Ala; Borstad, Christopher P.; Scheuchl, Bernd; Rignot, Eric; Seroussi, Helene

    2015-06-01

    Following the 2002 disintegration of the northern and central parts of the Larsen B Ice Shelf, the tributary glaciers of the southern surviving part initially appeared relatively unchanged and hence assumed to be buttressed sufficiently by the remnant ice shelf. Here, we modify this perception with observations from IceBridge altimetry and InSAR-inferred ice flow speeds. Our analyses show that the surfaces of Leppard and Flask glaciers directly upstream from their grounding lines lowered by 15 to 20 m in the period 2002-2011. The thinning appears to be dynamic as the flow of both glaciers and the remnant ice shelf accelerated in the same period. Flask Glacier started accelerating even before the 2002 disintegration, increasing its flow speed by ∼55% between 1997 and 2012. Starbuck Glacier meanwhile did not change much. We hypothesize that the different evolutions of the three glaciers are related to their dissimilar bed topographies and degrees of grounding. We apply numerical modeling and data assimilation that show these changes to be accompanied by a reduction in the buttressing afforded by the remnant ice shelf, a weakening of the shear zones between its flow units and an increase in its fracture. The fast flowing northwestern part of the remnant ice shelf exhibits increasing fragmentation, while the stagnant southeastern part seems to be prone to the formation of large rifts, some of which we show have delimited successive calving events. A large rift only 12 km downstream from the grounding line is currently traversing the stagnant part of the ice shelf, defining the likely front of the next large calving event. We propose that the flow acceleration, ice front retreat and enhanced fracture of the remnant Larsen B Ice Shelf presage its approaching demise.

  14. HIGH-RESOLUTION RADIO OBSERVATIONS OF THE REMNANT OF SN 1987A AT HIGH FREQUENCIES

    International Nuclear Information System (INIS)

    Zanardo, Giovanna; Staveley-Smith, L.; Potter, T. M.; Ng, C.-Y.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

    2013-01-01

    We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The 0.''35 × 0.''23 resolution of the diffraction-limited image is the highest achieved to date in high-dynamic range. We also present a new ATCA image at 18 GHz derived from 2011 observations, which is super-resolved to 0.''25. The flux density is 40 ± 2 mJy at 44 GHz and 81 ± 6 mJy at 18 GHz. At both frequencies, the remnant exhibits a ring-like emission with two prominent lobes, and an east-west brightness asymmetry that peaks on the eastern lobe. A central feature of fainter emission appears at 44 GHz. A comparison with previous ATCA observations at 18 and 36 GHz highlights higher expansion velocities of the remnant's eastern side. The 18-44 GHz spectral index is α = –0.80 (S ν ∝ν α ). The spectral index map suggests slightly steeper values at the brightest sites on the eastern lobe, whereas flatter values are associated with the inner regions. The remnant morphology at 44 GHz generally matches the structure seen with contemporaneous X-ray and Hα observations. Unlike the Hα emission, both the radio and X-ray emission peaks on the eastern lobe. The regions of flatter spectral index align and partially overlap with the optically visible ejecta. Simple free-free absorption models suggest that emission from a pulsar wind nebula or a compact source inside the remnant may now be detectable at high frequencies or at low frequencies if there are holes in the ionized component of the ejecta.

  15. Robotic membranes

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2008-01-01

    The relationship between digital and analogue is often constructed as one of opposition. The perception that the world is permeated with underlying patterns of data, describing events and matter alike, suggests that information can be understood apart from the substance to which it is associated......, and that its encoded logic can be constructed and reconfigured as an isolated entity. This disembodiment of information from materiality implies that an event like a thunderstorm, or a material like a body, can be described equally by data, in other words it can be read or written. The following prototypes......, Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual examination...

  16. Self lubricating fluid bearings

    International Nuclear Information System (INIS)

    Kapich, D.D.

    1980-01-01

    The invention concerns self lubricating fluid bearings, which are used in a shaft sealed system extending two regions. These regions contain fluids, which have to be isolated. A first seal is fluid tight for the first region between the carter shaft and the shaft. The second seal is fluid tight between the carter and the shaft, it communicates with the second region. The first fluid region is the environment surrounding the shaft carter. The second fluid region is a part of a nuclear reactor which contains the cooling fluid. The shaft is conceived to drive a reactor circulating and cooling fluid [fr

  17. Modern fluid dynamics

    CERN Document Server

    Kleinstreuer, Clement

    2018-01-01

    Modern Fluid Dynamics, Second Edition provides up-to-date coverage of intermediate and advanced fluids topics. The text emphasizes fundamentals and applications, supported by worked examples and case studies. Scale analysis, non-Newtonian fluid flow, surface coating, convection heat transfer, lubrication, fluid-particle dynamics, microfluidics, entropy generation, and fluid-structure interactions are among the topics covered. Part A presents fluids principles, and prepares readers for the applications of fluid dynamics covered in Part B, which includes computer simulations and project writing. A review of the engineering math needed for fluid dynamics is included in an appendix.

  18. Elevated Remnant Cholesterol Causes Both Low-Grade Inflammation and Ischemic Heart Disease, Whereas Elevated Low-Density Lipoprotein Cholesterol Causes Ischemic Heart Disease Without Inflammation

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Tybjærg-Hansen, Anne

    2013-01-01

    Elevated nonfasting remnant cholesterol and low-density lipoprotein (LDL) cholesterol are causally associated with ischemic heart disease (IHD), but whether elevated nonfasting remnant cholesterol and LDL cholesterol both cause low-grade inflammation is currently unknown....

  19. Spinal cerebrospinal fluid seeding of a clival chordoma; A case report

    International Nuclear Information System (INIS)

    Baek, Seung Hwan; Yu, In Kyu; Kim, Seong Min; Park, Ki Seok; Son, Hyun Jin

    2015-01-01

    Chordomas originate from remnants of the embryonic notochord and account for < 2% of all malignant bone tumors. Chordomas have a high rate of local recurrence. However, spinal cerebrospinal fluid (CSF) seeding of a chordoma is extremely rare. Here, we present a very rare case of clival chordoma with spinal seeding. Radiologists should consider spinal CSF seeding of a clival chordoma, particularly when accompanied by signs of dural perforation or caudal extension

  20. Spinal cerebrospinal fluid seeding of a clival chordoma; A case report

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seung Hwan; Yu, In Kyu; Kim, Seong Min; Park, Ki Seok; Son, Hyun Jin [Eulji University Hospital, Daejeon (Korea, Republic of)

    2015-07-15

    Chordomas originate from remnants of the embryonic notochord and account for < 2% of all malignant bone tumors. Chordomas have a high rate of local recurrence. However, spinal cerebrospinal fluid (CSF) seeding of a chordoma is extremely rare. Here, we present a very rare case of clival chordoma with spinal seeding. Radiologists should consider spinal CSF seeding of a clival chordoma, particularly when accompanied by signs of dural perforation or caudal extension.

  1. Free-standing biomimetic polymer membrane imaged with atomic force microscopy

    DEFF Research Database (Denmark)

    Rein, Christian; Pszon-Bartosz, Kamila Justyna; Jensen, Karin Bagger Stibius

    2011-01-01

    Fluid polymeric biomimetic membranes are probed with atomic force microscopy (AFM) using probes with both normal tetrahedrally shaped tips and nanoneedle-shaped Ag2Ga rods. When using nanoneedle probes, the collected force volume data show three distinct membrane regions which match the expected...... membrane structure when spanning an aperture in a hydrophobic scaffold. The method used provides a general method for mapping attractive fluid surfaces. In particular, the nanoneedle probing allows for characterization of free-standing biomimetic membranes with thickness on the nanometer scale suspended...... over 300-μm-wide apertures, where the membranes are stable toward hundreds of nanoindentations without breakage. © 2010 American Chemical Society....

  2. Estimation of Remnant Dentin Thickness under Proximal Caries Using Digital Bitewing Radiography: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Masoomeh Afsa

    2015-12-01

    Full Text Available Objectives: In restorative dentistry, it is essential to estimate the amount of remnant tooth structure after caries removal to make the best treatment plan. The present study was aimed to determine whether there is a correlation between the real thickness of remnant dentin under carious lesion and the radiographical measurement from photostimulable phosphor plates (PSPs. Methods: a whole number of 68 unrestored permanent human molar and premolar teeth with 82 proximal carious surfaces were mounted in an artificial arch. Digital bitewing radiographs with PSPs were taken, carious lesions were removed and radiographic imaging was repeated. Teeth were sectioned mesiodistally in two parts and thickness of remnant tooth structure to pulp was measured. Measurements of remnant dentin under caries from radiographic images and teeth structures were compared. Result: The mean measurements of remnant dentin on primary radiographs were statistically different from the measurements on teeth structures. The mean thickness of remnant dentin on tooth structure was around 30% less than what measured on radiographic image. Conclusion: The real thickness of remnant dentin under caries is about 70% of its thickness measured on digital bitewing radiographs prepared by PSPs as image receptor.

  3. AN X-RAY AND RADIO STUDY OF THE VARYING EXPANSION VELOCITIES IN TYCHO’S SUPERNOVA REMNANT

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brian J. [CRESST/USRA and X-ray Astrophysics Laboratory, NASA GSFC, 8800 Greenbelt Road, Greenbelt, MD, Code 662 (United States); Chomiuk, Laura [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Hewitt, John W. [University of North Florida, Department of Physics, 1 UNF Drive, Jacksonville, FL 32224 (United States); Blondin, John M.; Borkowski, Kazimierz J.; Reynolds, Stephen P. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Ghavamian, Parviz [Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD 21252 (United States); Petre, Robert, E-mail: brian.j.williams@nasa.gov [NASA GSFC, X-ray Astrophysics Laboratory, Greenbelt, MD 20771 (United States)

    2016-06-01

    We present newly obtained X-ray and radio observations of Tycho’s supernova remnant using Chandra and the Karl G. Jansky Very Large Array in 2015 and 2013/14, respectively. When combined with earlier epoch observations by these instruments, we now have time baselines for expansion measurements of the remnant of 12–15 years in the X-rays and 30 years in the radio. The remnant’s large angular size allows for proper motion measurements at many locations around the periphery of the blast wave. Consistent with earlier measurements, we find a clear gradient in the expansion velocity of the remnant, despite its round shape. The proper motions on the western and southwestern sides of the remnant are about a factor of two higher than those in the east and northeast. We showed in an earlier work that this is related to an offset of the explosion site from the geometric center of the remnant due to a density gradient in the ISM, and using our refined measurements reported here, we find that this offset is ∼23″ toward the northeast. An explosion center offset in such a circular remnant has implications for searches for progenitor companions in other remnants.

  4. Fluid mechanics in fluids at rest.

    Science.gov (United States)

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

  5. Sleeve Gastrectomy: Correlation of Long-Term Results with Remnant Morphology and Eating Disorders.

    Science.gov (United States)

    Tassinari, Daniele; Berta, Rossana D; Nannipieri, Monica; Giusti, Patrizia; Di Paolo, Luca; Guarino, Daniela; Anselmino, Marco

    2017-11-01

    Remnant dimension is considered one of the crucial elements determining the success of sleeve gastrectomy (SG), and dilation of the gastric fundus is often believed to be the main cause of failure. The main outcome of this study is to find correlations between remnant morphology in the immediate post-operative stage, its dilation in years, and the long-term results. The second purpose aims to correlate preoperative eating disorders, taste alteration, hunger perception, and early satiety with post-SG results. Remnant morphology was evaluated, in the immediate post-operative stage and over the years (≥2 years), through X-ray of the oesophagus-stomach-duodenum calculating the surface in anteroposterior (AP) and right anterior oblique projection (RAO). Presurgery diagnosis of eating disorders and their evaluation through "Eating Disorder Inventory-3" (EDI3) during follow-up were performed. Change in taste perception, sense of appetite, and early satiety were evaluated. Patients were divided into two groups: "failed SGs (EWL50%). There were a total of 50 patients (37 F, 13 M), with mean age 52 years, preoperative weight 131 ± 21.8 kg, and BMI 47.4 ± 6.8 kg/m 2 . Post-operative remnant mean dimensions overlapped between the two groups. On a long-term basis, an increase of 57.2 and 48.4% was documented in the AP and RAO areas respectively. In "failed" SGs, dilation was significantly superior to "efficient" SGs (AP area 70.2 vs 46.1%; RAO area 59.3 vs 39%; body width 102% vs 41.7%). Preoperative eating disorders were more present in efficient SGs than in failed SGs with the exception of sweet eating. There were no significant changes to taste perception during follow-up. Fifty-two percent of efficient SGs vs 26% of failed SGs reported a persistent lack of sense of hunger; similarly, 92.5 vs 78% declared the persistence of a sense of early satiety. The two groups did not statistically differ as far as all the variables of the EDI3 are concerned. On a long

  6. Radioiodine remnant ablation in differentiated thyroid cancer after combined endogenous and exogenous TSH stimulation.

    Science.gov (United States)

    Vrachimis, A; Schober, O; Riemann, B

    2012-01-01

    Radioiodine remnant ablation (RRA) after (near-)total thyroidectomy (TE) is a key element in patients with differentiated thyroid cancer (DTC). The use of exogenous TSH stimulation (rhTSH) prior to RRA has shown promising results as compared to conventional thyroid hormone withdrawal (THW). As yet, the efficacy of RRA after brief THW and single rhTSH administration has not been assessed. The study sample comprised 147 patients with DTC referred to our center between May 2008 and September 2010. All patients received TE with subsequent RRA. None of these 147 patients had evidence of distant metastasis. 93 patients had endogenous TSH stimulation 4-5 weeks after surgery (group I) and twenty-six received two rhTSH injections (group II). 28 patients were treated with a single rhTSH injection after a brief THW (group III). RRA-Efficacy was assessed three months after therapy by diagnostic whole-body scan and measurement of the tumour marker thyroglobulin (Tg) under TSH stimulation. Three categories of success were defined for remnant ablation. Based on the definition of successful remnant ablation no visible uptake and a Tg ≤ 2.0 ng/ml (category 1) was seen in 62/93 patients in group I, in 17/26 patients in group II (p = n.s.) and in 12/28 patients in group III (p 2.0 ng/ml (category 3) was found in 3/93 patients in group I and 1/26 patients in group II but in no patient in group III. The third strategy of remnant ablation using a single injection of rhTSH after a brief THW period resulted in a significant higher rate of patients with residual uptake in the thyroid bed and a Tg level below 2 ng/ml three months after remnant ablation in comparison to THW. However, the overall efficacy of the third protocol was not significantly different as compared to two rhTSH injections. Under the aspect of the supply shortage of rhTSH the combined endogenous and exogenous TSH stimulation may be an attractive alternative for remnant ablation in differentiated thyroid cancer.

  7. Reduced abrasion drilling fluid

    NARCIS (Netherlands)

    2010-01-01

    A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

  8. Reduced abrasion drilling fluid

    NARCIS (Netherlands)

    2012-01-01

    A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

  9. Process fluid cooling system

    International Nuclear Information System (INIS)

    Farquhar, N.G.; Schwab, J.A.

    1977-01-01

    A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

  10. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    Directory of Open Access Journals (Sweden)

    Maria URSACHI (BOLOTA

    2016-12-01

    Full Text Available The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amniotic sac (PRAS is defined as rupture of membranes before the onset of labor. Premature rupture of the fetal membrane, which occurs before 37 weeks of gestation, usually, refers to preterm premature rupture of membranes. Despite advances in the care period, premature rupture of membranes and premature rupture of membranes preterm continue to be regarded as serious obstetric complications. On the term 8% - 10% of pregnant women have premature rupture of membranes; these women are at increased risk of intrauterine infections, where the interval between membrane rupture and expulsion is rolled-over. Premature rupture of membranes preterm occurs in approximately 1% of all pregnancies and is associated with 30% -40% of preterm births. Thus, it is important to identify the cause of pre-term birth (after less than 37 completed weeks of "gestation" and its complications, including respiratory distress syndrome, neonatal infection and intraventricular hemorrhage. Objectives: the development of the protocol of the clinical trial on patients with impending preterm birth, study clinical and statistical on the socio-demographic characteristics of patients with imminent preterm birth; clinical condition of patients and selection of cases that could benefit from the application of interventional therapy; preclinical investigation (biological and imaging of patients with imminent preterm birth; the modality therapy; clinical investigation of the effectiveness of short

  11. Origins of saline fluids at convergent margins

    Science.gov (United States)

    Martin, Jonathan B.; Kastner, Miriam; Egeberg, Per Kr.

    The compositions of pore and venting fluids at convergent margins differ from seawater values, reflecting mixing and diagenesis. Most significantly, the concentration of Cl-, assumed to be a conservative ion, differs from its seawater value. Chloride concentrations could be elevated by four processes, although two, the formation of gas hydrate and ion filtration by clay membranes, are insignificant in forming saline fluids at convergent margins. During the formation of gas hydrate, the resulting Cl--rich fluids, estimated to contain an average excess of ˜140 mM Cl- over seawater value, probably would be flushed from the sediment when the pore fluids vent to seawater. Ion filtration by clay membranes requires compaction pressures typical of >2 km burial depths. Even at these depths, the efficiency of ion filtration will be negligible because (1) fluids will flow through fractures, thereby bypassing clay membranes, (2) concentrations of clay minerals are diluted by other phases, and (3) during burial, smectite converts to illite, which has little capacity for ion filtration. A third process, mixing with subaerially evaporated seawater, elevates Cl- concentrations to 1043 mM in forearc basins along the Peru margin. Evaporation of seawater, however, will be important only in limited geographic regions that are characterized by enclosed basins, arid climates, and permeable sediments. At the New Hebrides and Izu-Bonin margins, Cl- concentrations are elevated to a maximum of 1241 mM. The process responsible for this increase is the alteration of volcanic ash to hydrous clay and zeolite minerals. Mass balance calculations, based on the decrease in δ18O values to -9.5‰ (SMOW), suggest that the Cl- concentrations could increase solely from the formation of smectite in a closed system. The diagenesis of volcanic ash also alters the concentrations of most dissolved species in addition to Cl-. Depending on the volume of this altered fluid, it could influence seawater

  12. Fundamental Characteristics of the Newly Developed ATA™ Membrane Dialyzer.

    Science.gov (United States)

    Sunohara, Takashi; Masuda, Toshiaki

    2017-01-01

    Dialysis membranes are often made from synthetic polymers, such as polysulfone. However, membranes made from cellulose triacetate have superior biocompatibility and have been used since the 1980s. On-line hemodiafiltration treatment accompanied by massive fluid replacement is increasingly being used in Europe and Japan, but cellulose triacetate is not suitable for this treatment. Our newly developed asymmetric triacetate membrane, the ATA™ membrane, substantially improved the filtration properties and blood compatibility because of the asymmetric structure and smooth surface of this cellulose acetate membrane. Key Message: The ATA membrane maintains its high permeability even after massive filtration and shows less temporal variation in its permeation performance, lower protein adsorption, and superior biocompatibility compared with conventional membranes. © 2017 S. Karger AG, Basel.

  13. Nanoscale Membrane Domain Formation Driven by Cholesterol

    DEFF Research Database (Denmark)

    Javanainen, Matti; Martinez-Seara, Hector; Vattulainen, Ilpo

    2017-01-01

    Biological membranes generate specific functions through compartmentalized regions such as cholesterol-enriched membrane nanodomains that host selected proteins. Despite the biological significance of nanodomains, details on their structure remain elusive. They cannot be observed via microscopic...... dipalmitoylphosphatidylcholine and cholesterol - the "minimal standard" for nanodomain formation. The simulations reveal how cholesterol drives the formation of fluid cholesterol-rich nanodomains hosting hexagonally packed cholesterol-poor lipid nanoclusters, both of which show registration between the membrane leaflets....... The complex nanodomain substructure forms when cholesterol positions itself in the domain boundary region. Here cholesterol can also readily flip-flop across the membrane. Most importantly, replacing cholesterol with a sterol characterized by a less asymmetric ring region impairs the emergence of nanodomains...

  14. Discovery of recombining plasma from the faintest GeV supernova remnant HB 21 and a possible scenario for cosmic rays escaping from supernova remnant shocks

    Science.gov (United States)

    Suzuki, Hiromasa; Bamba, Aya; Nakazawa, Kazuhiro; Furuta, Yoshihiro; Sawada, Makoto; Yamazaki, Ryo; Koyama, Katsuji

    2018-06-01

    We present an X-ray study of the GeV gamma-ray supernova remnant (SNR) HB 21 with Suzaku. HB 21 is interacting with molecular clouds, and is the faintest in the GeV band among known GeV SNRs. We discovered strong radiative recombination continua of Si and S from the center of the remnant, which provide direct evidence of a recombining plasma (RP). The total emission can be explained with the RP and ionizing plasma components. The electron temperature and recombination timescale of the RP component were estimated as 0.17 (0.15-0.18) keV and 3.2 (2.0-4.8) × 1011 s cm-3, respectively. The estimated age of the RP (˜170 kyr) is the longest among known recombining GeV SNRs, because of a very low density of electrons (˜0.05 cm-3). We have examined the dependencies of GeV spectral indices on each of RP ages and SNR diameters for nine recombining GeV SNRs. Both showed possible positive correlations, indicating that both the parameters can be good indicators of properties of accelerated protons, for instance the degree of escape from SNR shocks. A possible scenario for a process of proton escape is introduced: interaction with molecular clouds makes weaker magnetic turbulence and cosmic-ray protons escape, simultaneously cooling down the thermal electrons and generating an RP.

  15. Limited and selective transfer of plasma membrane glycoproteins to membrane of secondary lysosomes

    International Nuclear Information System (INIS)

    Haylett, T.; Thilo, L.

    1986-01-01

    Radioactive galactose, covalently bound to cell surface glycoconjugates on mouse macrophage cells, P388D 1 , was used as a membrane marker to study the composition, and the kinetics of exchange, of plasma membrane-derived constituents in the membrane of secondary lysosomes. Secondary lysosomes were separated from endosomes and plasma membrane by self-forming Percoll density gradients. Horseradish peroxidase, taken up by fluid-phase pinocytosis, served as a vesicle contents marker to monitor transfer of endosomal contents into secondary lysosomes. Concurrently, the fraction of plasma membrane-derived label of secondary lysosomes increased by first order kinetics from 4 PAGE, labeled molecules of M/sub r/ 160-190 kD were depleted and of the M/sub r/ 100-120 kD were enriched in lysosome membrane compared with the relative composition of label on the cell surface. No corresponding selectivity was observed for the degradation of label, with all M/sub r/ classes being affected to the same relative extent. The results indicate that endocytosis-derived transfer of plasma membrane constitutents to secondary lysosomes is a limited and selective process, and that only ∼1% of internalized membrane is recycled via a membrane pool of secondary lysosomes

  16. Recent advances on polymeric membranes for membrane reactors

    KAUST Repository

    Buonomenna, M. G.; Choi, Seung Hak

    2012-01-01

    . The successful use of membranes in membrane reactors is primary the result of two developments concerning: (i) membrane materials and (ii) membrane structures. The selection of a suited material and preparation technique depends on the application the membrane

  17. Limitations of intraoperative adrenal remnant volume measurement in patients undergoing subtotal adrenalectomy.

    Science.gov (United States)

    Brauckhoff, Michael; Stock, Karsten; Stock, Susanne; Lorenz, Kerstin; Sekulla, Carsten; Brauckhoff, Katrin; Thanh, Phuong Nguyen; Gimm, Oliver; Spielmann, Rolf Peter; Dralle, Henning

    2008-05-01

    Recent studies have shown that a minimum of approximately one-third of one normal adrenal gland is required for sufficient adrenocortical stress capacity. Correlation between intraoperative measurement, determination of remnant size by computed tomography (CT), and adrenocortical stress capacity has not been examined so far. Twenty-two patients with familial pheochromocytoma (n=13), sporadic pheochromocytoma (n=3), and adrenocortical tumors (n=6) who underwent unilateral or bilateral subtotal adrenalectomy (STAE, 28 adrenal remnants) were prospectively studied. Patients were examined in a multi-slice CT to determine residual adrenal tissue and by ACTH test 4 days and 3 months postoperatively. There was a slight significant correlation between intraoperative and CT calculated volumes (r=0.77; pSTAE has limitations. CT gives larger volumes compared with intraoperative determination. For calculation of a volume-function correlation of residual adrenal tissue, in clinical practice, the determination of relative adrenal residual volume is acceptable.

  18. Probing Extreme-density Matter with Gravitational-wave Observations of Binary Neutron Star Merger Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Radice, David [Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540 (United States); Bernuzzi, Sebastiano [Department of Mathematical, Physical and Computer Sciences, University of Parma, I-43124 Parma (Italy); Pozzo, Walter Del [Dipartimento di Fisica “Enrico Fermi,” Università di Pisa, Pisa I-56127 (Italy); Roberts, Luke F. [NSCL/FRIB and Department of Physics and Astronomy, Michigan State University, 640 S Shaw Lane, East Lansing, MI 48824 (United States); Ott, Christian D. [TAPIR, Walter Burke Institute for Theoretical Physics, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)

    2017-06-20

    We present a proof-of-concept study, based on numerical-relativity simulations, of how gravitational waves (GWs) from neutron star merger remnants can probe the nature of matter at extreme densities. Phase transitions and extra degrees of freedom can emerge at densities beyond those reached during the inspiral, and typically result in a softening of the equation of state (EOS). We show that such physical effects change the qualitative dynamics of the remnant evolution, but they are not identifiable as a signature in the GW frequency, with the exception of possible black hole formation effects. The EOS softening is, instead, encoded in the GW luminosity and phase and is in principle detectable up to distances of the order of several megaparsecs with advanced detectors and up to hundreds of megaparsecs with third-generation detectors. Probing extreme-density matter will require going beyond the current paradigm and developing a more holistic strategy for modeling and analyzing postmerger GW signals.

  19. A newly-recognized galactic supernova remnant with shell-type and filled-center features

    International Nuclear Information System (INIS)

    Barnes, D.J.; Turtle, A.J.

    1988-01-01

    While the number of galactic supernova remnants (SNRs) now known is fairly large (>150), the subset among these that are known to resemble the Crab Nebula is still distressingly small, about 15 or so. Thus any object that can be unambiguously included in this exclusive club forms a valuable addition to knowledge of this class. The authors report observations of a newly recognized nonthermal galactic object, G18.94-1.06, having all the hallmarks of the classical shell-type SNRs, while also appearing to have a filled-centre component located inside the shell. Among the known Crab-like remnants, about one third show this dual nature. This diagnosis of G18.94-1.06 is supported mainly by the variations in spectral index across the source, as seen between the two observation frequencies, 408 MHz and 5.0 GHz

  20. Spectroscopic observations of the supernova remnant candidates 3 C 400.2 and S91

    International Nuclear Information System (INIS)

    Sabbadin, F.; D'Odorico, S.

    1976-01-01

    Spectra of 3 C 400.2 and S 91 have been used to measure the emission line rations Hα/N II region, Hα/ SII region and 6,717/6,731 of S II region in the two nebulae. By comparing the measured ratios with the mean values observed in supernova remnants, in planetary nebulae und in glactic H II regions, it is possible to conclude that the two nebulae are the result of supernova explosions. For S 91, previously catalogued as an H II region, we derive a linear diameter of 34 pc and a distance of 0.7 kpc using a relation between the diameter of supernova remnants and the average Hα/ N II region intensity ratio in their optical filaments. (orig.) [de

  1. FERMI LARGE AREA TELESCOPE DETECTION OF THE YOUNG SUPERNOVA REMNANT TYCHO

    International Nuclear Information System (INIS)

    Giordano, F.; Naumann-Godo, M.; Ballet, J.; Bechtol, K.; Funk, S.; Lande, J.; Tanaka, T.; Uchiyama, Y.; Mazziotta, M. N.; Rainò, S.; Tibolla, O.

    2012-01-01

    After almost three years of data taking in sky-survey mode, the Fermi Large Area Telescope has detected γ-ray emission toward Tycho's supernova remnant (SNR). The Tycho SNR is among the youngest remnants in the Galaxy, originating from a Type Ia Supernova in AD 1572. The γ-ray integral flux from 400 MeV up to 100 GeV has been measured to be (3.5 ± 1.1 stat ± 0.7 syst )× 10 –9 cm –2 s –1 with a photon index of 2.3 ± 0.2 stat ± 0.1 syst . A simple model consistent with TeV, X-ray, and radio data is sufficient to explain the observed emission as originating from π 0 decays as a result of cosmic-ray acceleration and interaction with the ambient medium.

  2. Probing Extreme-density Matter with Gravitational-wave Observations of Binary Neutron Star Merger Remnants

    International Nuclear Information System (INIS)

    Radice, David; Bernuzzi, Sebastiano; Pozzo, Walter Del; Roberts, Luke F.; Ott, Christian D.

    2017-01-01

    We present a proof-of-concept study, based on numerical-relativity simulations, of how gravitational waves (GWs) from neutron star merger remnants can probe the nature of matter at extreme densities. Phase transitions and extra degrees of freedom can emerge at densities beyond those reached during the inspiral, and typically result in a softening of the equation of state (EOS). We show that such physical effects change the qualitative dynamics of the remnant evolution, but they are not identifiable as a signature in the GW frequency, with the exception of possible black hole formation effects. The EOS softening is, instead, encoded in the GW luminosity and phase and is in principle detectable up to distances of the order of several megaparsecs with advanced detectors and up to hundreds of megaparsecs with third-generation detectors. Probing extreme-density matter will require going beyond the current paradigm and developing a more holistic strategy for modeling and analyzing postmerger GW signals.

  3. X-ray characteristics of the Lupus Loop and SN1006 supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Toor, A [California Univ., Livermore (USA). Lawrence Livermore Lab.

    1980-01-01

    The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest X-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 100 keV) from our observation and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology.

  4. X-ray characteristics of the Lupus Loop and SN1006 supernova remnants

    International Nuclear Information System (INIS)

    Toor, A.

    1980-01-01

    The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest X-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 100 keV) from our observation and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology. (orig.)

  5. A hydrodynamical model of Kepler's supernova remnant constrained by x-ray spectra

    International Nuclear Information System (INIS)

    Ballet, J.; Arnaud, M.; Rothinfluo, R.; Chieze, J.P.; Magne, B.

    1988-01-01

    The remnant of the historical supernova observed by Kepler in 1604 was recently observed in x-rays by the EXOSAT satellite up to 10 keV. A strong Fe K emission line around 6.5 keV is readily apparent in the spectrum. From an analysis of the light curve of the SN, reconstructed from historical descriptions, a previous study proposed to classify it as type I. Standard models of SN I based on carbon deflagration of white dwarf predict the synthesis of about 0.5 M circle of iron in the ejecta. Observing the iron line is a crucial check for such models. It has been argued that the light curve of Sn II-L is very similar to that of SN I and that the original observations are compatible with either type. In view of this uncertainty the authors have run a hydrodynamics-ionization code for both SN II and SN I remnants

  6. X-ray emission from supernova remnants with particular reference to the Cygnus Loop

    International Nuclear Information System (INIS)

    Gronenschild, E.H.B.M.

    1979-01-01

    Observational or theoretical results related to the study of supernova remnants (SNRs) are described. Some background information is given by reviewing the present status of our knowledge of supernovae and supernova remnants, both from theory and observations. Also the distribution of all known radio, optical, and X-ray SNRs in the Galaxy is shown and a comparison is made. The X-ray observations of the well-known X-ray SNR the Cygnus Loop are discussed in detail and the discovery of a new X-ray emitting SNR W44 is described. Other radio sources are investigated, and the observed X-ray emission of SNRs are analysed using thermal spectra like exponential or bremsstrahlung spectra. The X-ray line spectrum that emerges from SNRs is described in detail. (Auth.)

  7. Coexistence of monatomic and diatomic molecular fluid character in liquid gallium

    Energy Technology Data Exchange (ETDEWEB)

    Gong, X.G. (International Centre for Theoretical Physics (ICTP), Trieste (Italy)); Chiarotti, G.L. (International School for Advanced Studies (SISSA), Trieste (Italy) Lab. Tecnologie Avanzate Superfici e Catalisi (TASC), Consorzio Interuniv. Nazionale per la Fisica della Materia (INFM), Trieste (Italy)); Parrinello, M. (IBM Research Div., Zurich Forschungslab., Rueschlikon (Switzerland) International School for Advanced Studies (SISSA), Trieste (Italy)); Tosatti, E. (International School for Advanced Studies (SISSA), Trieste (Italy) International Centre for Theoretical Physics (ICTP), Trieste (Italy) IBM Research Div., Zurich Forschungslab., Rueschlikon (Switzerland))

    1993-02-01

    We have performed an ab initio molecular-dynamics simulation of liquid Ga at high temperature (1000 K). Our results are in good agreement with scattering data and with Knight-shift experiments. A remarkable feature of our findings is the coexistence in the liquid state of metallic and covalent characters. Covalency manifests itself in the appearance of very short-lived Ga-Ga bonds, which represent remnants in the liquid of the crystalline form [alpha]-Ga. We set up a two-fluid scheme which can be used for the analysis of fluids where metallic and covalent characters coexist. (orig.).

  8. Coexistence of monatomic and diatomic molecular fluid character in liquid gallium

    International Nuclear Information System (INIS)

    Gong, X.G.; Chiarotti, G.L.; Parrinello, M.; Tosatti, E.

    1993-01-01

    We have performed an ab initio molecular-dynamics simulation of liquid Ga at high temperature (1000 K). Our results are in good agreement with scattering data and with Knight-shift experiments. A remarkable feature of our findings is the coexistence in the liquid state of metallic and covalent characters. Covalency manifests itself in the appearance of very short-lived Ga-Ga bonds, which represent remnants in the liquid of the crystalline form α-Ga. We set up a two-fluid scheme which can be used for the analysis of fluids where metallic and covalent characters coexist. (orig.)

  9. Duty-cycle and energetics of remnant radio-loud AGN

    Science.gov (United States)

    Turner, Ross J.

    2018-05-01

    Deriving the energetics of remnant and restarted active galactic nuclei (AGNs) is much more challenging than for active sources due to the complexity in accurately determining the time since the nucleus switched-off. I resolve this problem using a new approach that combines spectral ageing and dynamical models to tightly constrain the energetics and duty-cycles of dying sources. Fitting the shape of the integrated radio spectrum yields the fraction of the source age the nucleus is active; this, in addition to the flux density, source size, axis ratio, and properties of the host environment, provides a constraint on dynamical models describing the remnant radio source. This technique is used to derive the intrinsic properties of the well-studied remnant radio source B2 0924+30. This object is found to spend 50_{-12}^{+14} Myr in the active phase and a further 28_{-5}^{+6} Myr in the quiescent phase, have a jet kinetic power of 3.6_{-1.7}^{+3.0}× 10^{37} W, and a lobe magnetic field strength below equipartition at the 8σ level. The integrated spectra of restarted and intermittent radio sources are found to yield a `steep-shallow' shape when the previous outburst occurred within 100 Myr. The duty-cycle of B2 0924+30 is hence constrained to be δ < 0.15 by fitting the shortest time to the previous comparable outburst that does not appreciably modify the remnant spectrum. The time-averaged feedback energy imparted by AGNs into their host galaxy environments can in this manner be quantified.

  10. Former food products safety: microbiological quality and computer vision evaluation of packaging remnants contamination.

    Science.gov (United States)

    Tretola, M; Di Rosa, A R; Tirloni, E; Ottoboni, M; Giromini, C; Leone, F; Bernardi, C E M; Dell'Orto, V; Chiofalo, V; Pinotti, L

    2017-08-01

    The use of alternative feed ingredients in farm animal's diets can be an interesting choice from several standpoints, including safety. In this respect, this study investigated the safety features of selected former food products (FFPs) intended for animal nutrition produced in the framework of the IZS PLV 06/14 RC project by an FFP processing plant. Six FFP samples, both mash and pelleted, were analysed for the enumeration of total viable count (TVC) (ISO 4833), Enterobacteriaceae (ISO 21528-1), Escherichia coli (ISO 16649-1), coagulase-positive Staphylococci (CPS) (ISO 6888), presumptive Bacillus cereus and its spores (ISO 7932), sulphite-reducing Clostridia (ISO 7937), yeasts and moulds (ISO 21527-1), and the presence in 25 g of Salmonella spp. (ISO 6579). On the same samples, the presence of undesired ingredients, which can be identified as remnants of packaging materials, was evaluated by two different methods: stereomicroscopy according to published methods; and stereomicroscopy coupled with a computer vision system (IRIS Visual Analyzer VA400). All FFPs analysed were safe from a microbiological point of view. TVC was limited and Salmonella was always absent. When remnants of packaging materials were considered, the contamination level was below 0.08% (w/w). Of note, packaging remnants were found mainly from the 1-mm sieve mesh fractions. Finally, the innovative computer vision system demonstrated the possibility of rapid detection for the presence of packaging remnants in FFPs when combined with a stereomicroscope. In conclusion, the FFPs analysed in the present study can be considered safe, even though some improvements in FFP processing in the feeding plant can be useful in further reducing their microbial loads and impurity.

  11. The Cherenkov Telescope Array potential for the study of young supernova remnants

    Czech Academy of Sciences Publication Activity Database

    Acharya, B.S.; Aramo, C.; Babic, A.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Hrabovský, Miroslav; Janeček, Petr; Mandát, Dušan; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr

    2015-01-01

    Roč. 62, Mar (2015), s. 152-164 ISSN 0927-6505 R&D Projects: GA MŠk(CZ) 7AMB12AR013; GA MŠk LE13012; GA MŠk LG14019 Institutional support: RVO:68378271 Keywords : acceleration of particles * gamma rays: general * ISM: supernova remnants * radiation mechanisms: non-termal Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.425, year: 2015

  12. Exploring the Diffuse X-ray Emission of Supernova Remnant Kesteven 69 with XMM-Newton

    Directory of Open Access Journals (Sweden)

    Kyoung-Ae Seo

    2013-06-01

    Full Text Available We have investigated the X-ray emission from the shock-heated plasma of the Galactic supernova remnant Kesteven 69 with XMM-Newton. Assuming the plasma is at collisional ionization equilibrium, a plasma temperature and a column absorption are found to be kT ~ 0.62 keV and NH ~ 2.85 ×1022 cm-2 respectively by imaging spectroscopy. Together with the deduced emission measure, we place constraints on its Sedov parameters.

  13. Abiotic factors drives floristic variations of fern’s metacommunity in an Atlantic Forest remnant

    OpenAIRE

    L. E. N. Costa; R. P. Farias; A. C. P. Santiago; I. A. A. Silva; I. C. L. Barros

    2018-01-01

    Abstract We analyzed floristic variations in fern’s metacommunity at the local scale and their relationship with abiotic factors in an Atlantic Forest remnant of northeastern Brazil. Floristic and environmental variations were accessed on ten plots of 10 × 20 m. We performed cluster analyses, based on Bray-Curtis dissimilarity index to establish the floristic relationship. The influence of abiotic factors: luminosity, temperature, relative air humidity and relative soil moisture was evaluated...

  14. Toward the Understanding of the Physical Origin of Recombining Plasma in the Supernova Remnant IC 443

    Science.gov (United States)

    Matsumura, Hideaki; Tanaka, Takaaki; Uchida, Hiroyuki; Okon, Hiromichi; Tsuru, Takeshi Go

    2017-12-01

    We perform a spatially resolved spectroscopic analysis of X-ray emission from the supernova remnant (SNR) IC 443 with Suzaku. All of the spectra are well reproduced by a model consisting of a collisional ionization equilibrium (CIE) and two recombining plasma (RP) components. Although previous X-ray studies found an RP in the northeastern region, this is the first report on RPs in the other parts of the remnant. The electron temperature, kT e , of the CIE component is almost uniform at ∼0.2 keV across the remnant. The CIE plasma has metal abundances consistent with solar and is concentrated toward the rim of the remnant, suggesting that it is of shocked interstellar medium origin. The two RP components have different kT e : one in the range of 0.16–0.28 keV and the other in the range of 0.48–0.67 keV. The electron temperatures of both RP components decrease toward the southeast, where the SNR shock is known to be interacting with a molecular cloud. We also find the normalization ratio of the lower-kT e RP to higher-kT e RP components increases toward the southeast. Both results suggest the X-ray emitting plasma in the southeastern region is significantly cooled by some mechanism. One of the plausible cooling mechanisms is a thermal conduction between the hot plasma and the molecular cloud. If the cooling proceeds faster than the recombination timescale of the plasma, the same mechanism can account for the recombining plasma as well.

  15. EVOLUTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: MORPHOLOGICAL CHANGES FROM DAY 7000

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Zanardo, G.; Potter, T. M.; Staveley-Smith, L. [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia); Gaensler, B. M. [Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Manchester, R. N.; Tzioumis, A. K., E-mail: ncy@bohr.physics.hku.hk [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Marsfield, NSW 1710 (Australia)

    2013-11-10

    We present radio imaging observations of supernova remnant 1987A at 9 GHz, taken with the Australia Telescope Compact Array over 21 years from 1992 to 2013. By employing a Fourier modeling technique to fit the visibility data, we show that the remnant structure has evolved significantly since day 7000 (mid-2006): the emission latitude has gradually decreased such that the overall geometry has become more similar to a ring structure. Around the same time, we find a decreasing trend in the east-west asymmetry of the surface emissivity. These results could reflect the increasing interaction of the forward shock with material around the circumstellar ring, and the relative weakening of the interaction with the lower-density material at higher latitudes. The morphological evolution caused an apparent break in the remnant expansion measured with a torus model, from a velocity of 4600{sup +150}{sub -}200 km s{sup –1} between day 4000 and 7000 to 2400{sup +100}{sub -200} km s{sup –1} after day 7000. However, we emphasize that there is no conclusive evidence for a physical slowing of the shock at any given latitude in the expanding remnant, and that a change of radio morphology alone appears to dominate the evolution. This is supported by our ring-only fits which show a constant expansion of 3890 ± 50 km s{sup –1} without deceleration between days 4000 and 9000. We suggest that once the emission latitude no longer decreases, the expansion velocity obtained from the torus model should return to the same value as that measured with the ring model.

  16. Method of calculation of tanks forced ventilation from the remnants of liquid products

    Directory of Open Access Journals (Sweden)

    С. О. Пузік

    2013-07-01

    Full Text Available The advantages of gasoline compared to other petroleum products in terms of feasibility of their research. Calculations of the duration of ventilation and changes in the concentration of vapors of gasoline remains in the gas space of the vertical tank with a capacity of 1000 m3 (RUS-1000. Nomogram constructed for the quantitative forecast available liquid balances petrol A-95 and the time duration ventylyaiyi RUS-1000 from the remnants of the petrol

  17. Seed shadow of Swietenia macrophylla remnant trees in a Mexican rainforest: Implications for forest management

    OpenAIRE

    Alcalá, Raúl E.; Alonso, Roxalma L.; Gutiérrez-Granados, Gabriel

    2014-01-01

    The understanding of processes affecting the regeneration and coexistence of tree species is of high concern in tropical landscapes disturbed by anthropogenic activities. In this study, we evaluated the seed shadow of eight small remnant Swietenia macrophylla trees to determine the possible consequences of selective logging on the first stages of natural regeneration. We expected to find a restricted dispersal ability and a marked loss of seeds due to biotic interactions. To test this, seed s...

  18. Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

    Energy Technology Data Exchange (ETDEWEB)

    Potter, T. M.; Staveley-Smith, L. [International center for Radio Astronomy Research (ICRAR) M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Reville, B. [Center for Plasma Physics, Queen' s University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Bicknell, G. V.; Sutherland, R. S. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 0200 (Australia); Wagner, A. Y., E-mail: tobympotter@gmail.com [Center for Computational Sciences, Tsukuba University, Tsukuba, Ibaraki, 305-8577 (Japan)

    2014-10-20

    The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove and McKee progenitor with an envelope mass of 10 M {sub ☉} and an energy of 1.5 × 10{sup 44} J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 ± 0.''01 and maximum particle number density of (7.11 ± 1.78) × 10{sup 7} m{sup –3} produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.

  19. An unusual case of cancer of the urachal remnant following repair of bladder exstrophy.

    LENUS (Irish Health Repository)

    Fanning, D M

    2012-02-01

    INTRODUCTION: We report the first case of cancer of the urachal remnant following repair of bladder exstrophy, in a renal transplant recipient. METHOD: A retrospective review of this clinical case and the associated literature were performed. CONCLUSION: This unusual case highlights two very rare entities. Bladder exstrophy has an incidence of 1 in 50,000 newborns, whereas urachal cancer accounts for less than 1% of all bladder tumours.

  20. An unusual case of cancer of the urachal remnant following repair of bladder exstrophy.

    LENUS (Irish Health Repository)

    Fanning, D M

    2009-03-18

    INTRODUCTION: We report the first case of cancer of the urachal remnant following repair of bladder exstrophy, in a renal transplant recipient. METHOD: A retrospective review of this clinical case and the associated literature were performed. CONCLUSION: This unusual case highlights two very rare entities. Bladder exstrophy has an incidence of 1 in 50,000 newborns, whereas urachal cancer accounts for less than 1% of all bladder tumours.

  1. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  2. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

    2013-01-01

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  3. Examining hemodialyzer membrane performance using proteomic technologies

    Directory of Open Access Journals (Sweden)

    Bonomini M

    2017-12-01

    Full Text Available Mario Bonomini,1 Luisa Pieroni,2 Lorenzo Di Liberato,1 Vittorio Sirolli,1 Andrea Urbani2,3 1Department of Medicine, G. d’Annunzio University, Chieti, 2Proteomic and Metabonomic Units, IRCCS S. Lucia Foundation, Rome, 3Faculty of Medicine, Biochemistry and Clinical Biochemistry Institute, Catholic University of the “Sacred Heart”, Rome, Italy Abstract: The success and the quality of hemodialysis therapy are mainly related to both clearance and biocompatibility properties of the artificial membrane packed in the hemodialyzer. Performance of a membrane is strongly influenced by its interaction with the plasma protein repertoire during the extracorporeal procedure. Recognition that a number of medium–high molecular weight solutes, including proteins and protein-bound molecules, are potentially toxic has prompted the development of more permeable membranes. Such membrane engineering, however, may cause loss of vital proteins, with membrane removal being nonspecific. In addition, plasma proteins can be adsorbed onto the membrane surface upon blood contact during dialysis. Adsorption can contribute to the removal of toxic compounds and governs the biocompatibility of a membrane, since surface-adsorbed proteins may trigger a variety of biologic blood pathways with pathophysiologic consequences. Over the last years, use of proteomic approaches has allowed polypeptide spectrum involved in the process of hemodialysis, a key issue previously hampered by lack of suitable technology, to be assessed in an unbiased manner and in its full complexity. Proteomics has been successfully applied to identify and quantify proteins in complex mixtures such as dialysis outflow fluid and fluid desorbed from dialysis membrane containing adsorbed proteins. The identified proteins can also be characterized by their involvement in metabolic and signaling pathways, molecular networks, and biologic processes through application of bioinformatics tools. Proteomics may

  4. Magnetic Resonance Evaluation of Müllerian Remnants in Mayer-Rokitansky-Küster-Hauser Syndrome

    International Nuclear Information System (INIS)

    Yoo, Roh-Eul; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup

    2013-01-01

    To analyze magnetic resonance imaging (MRI) findings of Müllerian remnants in young females clinically suspected of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome in a primary amenorrhea workup. Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Müllerian remnants, vagina, ovaries, and associated findings. All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 ± 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. Typical Müllerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome

  5. Practical Aspects of X-ray Imaging Polarimetry of Supernova Remnants and Other Extended Sources

    Directory of Open Access Journals (Sweden)

    Jacco Vink

    2018-04-01

    Full Text Available The new generation of X-ray polarisation detectors, the gas pixel detectors, which will be employed by the future space missions IXPE and eXTP, allows for spatially resolved X-ray polarisation studies. This will be of particular interest for X-ray synchrotron emission from extended sources like young supernova remnants and pulsar wind nebulae. Here we report on employing a polarisation statistic that can be used to makes maps in the Stokes I, Q, and U parameters, a method that we expand by correcting for the energy-dependent instrumental modulation factor, using optimal weighting of the signal. In order to explore the types of Stokes maps that can be obtained, we present a Monte Carlo simulation program called xpolim, with which different polarisation weighting schemes are explored. We illustrate its use with simulations of polarisation maps of young supernova remnants, after having described the general science case for polarisation studies of supernova remnants, and its connection to magnetic-field turbulence. We use xpolim simulations to show that in general deep, ~2 Ms observations are needed to recover polarisation signals, in particular for Cas A, for which in the polarisation fraction may be as low as 5%.

  6. Explaining the morphology of supernova remnant (SNR) 1987A with the jittering jets explosion mechanism

    Science.gov (United States)

    Bear, Ealeal; Soker, Noam

    2018-04-01

    We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disk or belt. The accretion disk/belt launches the jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disk/belt is comparable to the duration of a typical jet-launching episode in the jittering jets explosion mechanism, and hence the disk/belt has no time to relax. We suggest that this might explain two unequal opposite jets that later lead to unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from neutrino-driven explosion to a jet-driven explosion of CCSNe.

  7. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Cholis, Ilias [Johns Hopkins U.; Hooper, Dan [Chicago U., KICP; Linden, Tim [Ohio State U.

    2017-01-16

    The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $\\bar{p}/p$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $\\bar{p}/p$ ratio observed at rigidities above $\\sim$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.

  8. MULTI-WAVELENGTH ANALYSIS OF THE GALACTIC SUPERNOVA REMNANT MSH 11-61A

    Energy Technology Data Exchange (ETDEWEB)

    Auchettl, Katie; Slane, Patrick; Foster, Adam R.; Smith, Randall K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Castro, Daniel [MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2015-09-01

    Due to its centrally bright X-ray morphology and limb brightened radio profile, MSH 11–61A (G290.1–0.8) is classified as a mixed morphology supernova remnant (SNR). H i and CO observations determined that the SNR is interacting with molecular clouds found toward the north and southwest regions of the remnant. In this paper we report on the detection of γ-ray emission coincident with MSH 11–61A, using 70 months of data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. To investigate the origin of this emission, we perform broadband modeling of its non-thermal emission considering both leptonic and hadronic cases and concluding that the γ-ray emission is most likely hadronic in nature. Additionally we present our analysis of a 111 ks archival Suzaku observation of this remnant. Our investigation shows that the X-ray emission from MSH 11–61A arises from shock-heated ejecta with the bulk of the X-ray emission arising from a recombining plasma, while the emission toward the east arises from an ionizing plasma.

  9. Association of intima-media thickness of carotid arteries with remnant lipoproteins in men and women.

    Science.gov (United States)

    Piťha, J; Kovář, J; Škodová, Z; Cífková, R; Stávek, P; Červenka, L; Šejda, T; Lánská, V; Poledne, R

    2015-01-01

    The subclass of triglyceride-rich lipoproteins - remnant-like particles (RLP) seems to be strong and independent risk factor for cardiovascular disease. We evaluated the role of RLP and other risk factors (RF) with sonographically measured intima-media thickness of carotid arteries (IMT CCA) in a cohort of Czech population including women defined according to the time after menopause. We investigated relation of IMT CCA to age, weight, central obesity, plasma lipids including remnant-like particles cholesterol (RLP-C) and triglycerides (RLP-TG) in 136 men and 160 women. Using multiple linear regression analysis, significant association between IMT CCA and RLP-C was found in women 1-7 years after menopause. In the whole group of women, only age and fasting blood glucose were independently associated with IMT CCA. In men only age significantly correlated with IMT CCA. Significant decrease of all plasma lipids between 1988 and 1996 in men was detected, while in women significant increase in triglycerides and no change in non-HDL cholesterol was observed. RLP-C was the strongest independent RF for atherosclerosis in postmenopausal women but its association with IMT CCA was limited to several years after menopause. In conclusion, women changing reproductive status could be more sensitive to atherogenic impact of remnant lipoproteins.

  10. Magnetic Resonance Evaluation of Müllerian Remnants in Mayer-Rokitansky-Küster-Hauser Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Roh-Eul; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup [Department of Radiology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2013-07-01

    To analyze magnetic resonance imaging (MRI) findings of Müllerian remnants in young females clinically suspected of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome in a primary amenorrhea workup. Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Müllerian remnants, vagina, ovaries, and associated findings. All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 ± 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. Typical Müllerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome.

  11. Incidence of metachronous gastric cancer in the remnant stomach after synchronous multiple cancer surgery.

    Science.gov (United States)

    Nozaki, Isao; Hato, Shinji; Kobatake, Takaya; Ohta, Koji; Kubo, Yoshirou; Nishimura, Rieko; Kurita, Akira

    2014-01-01

    In the preoperative evaluation for gastric cancer, high-resolution endoscopic technologies allow us to detect small accessory lesions. However, it is not known if the gastric remnant after partial gastrectomy for synchronous multiple gastric cancers has a greater risk for metachronous cancer. The purpose of this study was to determine the incidence of metachronous cancer in this patient subset compared with that after solitary cancer surgery. Data on a consecutive series of 1,281 patients gastrectomized for early gastric cancer from 1991 to 2007 were analyzed retrospectively. The 715 gastric remnants after distal gastrectomy were periodically surveyed by endoscopic examination in Shikoku Cancer Center. Among those surveyed cases, 642 patients were pathologically diagnosed with solitary lesion (SO group) and 73 patients with synchronous multiple lesions (MU group) at the time of the initial surgery. In the follow-up period, 15 patients in the SO group and 3 patients in the MU group were diagnosed as having metachronous cancer in the gastric remnant. The cumulative 4-year incidence rate was 1.9 % in the SO group and 5.5 % in the MU group. The difference did not reach the significant level by the log-rank test. The incidence of metachronous cancer is higher after multiple cancer surgery; however, the difference is not statistically significant.

  12. Optical pulsar in the Large Magellanic Cloud remnant 0540-69.3

    International Nuclear Information System (INIS)

    Middleditch, J.; Pennypacker, C.R.

    1984-01-01

    We have detected pulsed optical emission from the Large Magellanic Cloud (LMC) X-ray pulsar PSR 0540-693 (Seward et al. 1984). The pulsed emission has a time averaged magnitude of approximately 22.7. The X-ray pulsar was discovered in the LMC remnant, 0540-69.3 as a pulse repetition period of approx. 50 milliseconds (ms) in Einstein Obsrvatory data (Seward et al. 1984). Earlier, Clark et al. (1982) had noted that this remnant resembles the Crab Nebula because of the X-ray power law spectrum, and suggested that the nebular emission was synchrotron radiation powered by a central pulsar. After the announcement of X-ray pulsed emission, Chanan et al. (1984) measured the broad optical band properties of the nebula and found evidence for synchrotron emission. They reported that the 4.5 arc second continuum emission remnant has only a tenth the luminosity of the Crab Nebula. We have recorded broad-band optical time-series data at 1 ms intervals with the 4-m and 1.5-m Cerro Tololo telescopes and have found strong pulsations, employing the usual Fourier transform methods. A summary of the observations, including magnitudes, barycentric frequencies and times of arrival is given

  13. Cygnus Loop supernova remnant: new observations and a framework for understanding its structure and evolution

    International Nuclear Information System (INIS)

    Hester, J.J.

    1985-01-01

    New observational data on the Cygnus Loop supernova remnant (SNR) include: (1) a detailed high resolution comparison of x-ray and optical emission for a field in the SE; (2) a map of the [O III] electron temperature for the field previously studied by Hester, Parker, and Dufour (1983); and (3) CCD imagery of the NE limb in the light of four emission lines. A wide range of new and existing observations of the Loop are for the first time interpreted within the context of a single physical description. The Cygnus Loop is not an evaporative SNR evolving into the McKee and Ostriker (1977) ISM, nor are tiny cloudlets necessary to explain its morphology. The data show the Cygnus Loop to be evolving into a medium consisting primarily of an intercloud phase with N 0 approx. 0.1 cm -3 containing clouds with parsec dimensions and N 0 less than or equal to 10 cm -3 . The optical emission arises from extensive sheet like radiative shock fronts driven into the clouds. These fronts locally form the outer boundary of the remnant. The appearance of x-ray emission outside the optical emission on the limbs is due solely to projection effects. The distorted and bumpy shock front is shown to give rise in projection to the filamentary morphology of the remnant

  14. A deep optical imaging study of the nebular remnants of classical novae

    Science.gov (United States)

    Slavin, A. J.; O'Brien, T. J.; Dunlop, J. S.

    1995-09-01

    An optical imaging study of old nova remnants has revealed previously unobserved features in the shells of 13 classical novae - DQ Her, FH Ser, HR Del, GK Per, V1500 Cyg, T Aur, V533 Her, NQ Vul, V476 Cyg, DK Lac, LV Vul, RW UMi and V450 Cyg. These data indicate a possible correlation between nova speed class and the ellipticity of the resulting remnants - those of faster novae tend to comprise randomly distributed clumps of ejecta superposed on spherically symmetric diffuse material, whilst slower novae produce more structured ellipsoidal remnants with at least one and sometimes several rings of enhanced emission. By measuring the extent of the resolved shells and combining this information with previously published ejection speeds, we use expansion parallax to estimate distances for the 13 novae. Whilst we are able to deduce new information about every nova, it is notable that these observations include the first detections of shells around the old novae V450 Cyg and NQ Vul, and that velocity-resolved images of FH Ser and DQ Her have enabled us to estimate their orbital inclinations. Our observations of DQ Her also show that the main ellipsoidal shell is constricted by three rings and surrounded by a faint halo; this halo contains long tails extending outwards from bright knots, perhaps indicating that during or after outburst a fast inner wind has broken through the fractured principal shell.

  15. Hepatectomy Based on Future Liver Remnant Plasma Clearance Rate of Indocyanine Green

    Directory of Open Access Journals (Sweden)

    Yuichiro Uchida

    2016-01-01

    Full Text Available Background. Hepatectomy, an important treatment modality for liver malignancies, has high perioperative morbidity and mortality rates. Safe, comprehensive criteria for selecting patients for hepatectomy are needed. Since June 2011, we have used a cut-off value of ≧ 0.05 for future liver remnant plasma clearance rate of indocyanine green as a criterion for hepatectomy. The aim of this study was to verify the validity of this criterion. Methods. From June 2011 to December 2015, 212 hepatectomies were performed in Tenri Yorozu Hospital. Of these 212 patients, 107 who underwent preoperative computed tomography imaging volumetry, indocyanine green clearance test, and hepatectomy (excluding partial resection or enucleation were retrospectively analyzed. Results. There was no postoperative mortality. Posthepatectomy liver failure occurred in 59 patients (55.1% (International Study Group of Liver Surgery Grade A: 43 cases (40.2%, Grade B: 16 cases (15.0%, and Grade C: no cases. Operative morbidity greater than Clavien-Dindo Grade 3 occurred in 23 patients (21.5%. A low future liver remnant plasma clearance rate of indocyanine green was a good predictor for Grade B cases (area under curve = 0.804; 95% confidence interval, 0.712–0.895. Conclusion. Liver remnant plasma clearance rate of indocyanine green is a valid criterion for hepatectomy.

  16. Effect of cascade remnants on freely migrating defects in Cu-1% Au alloys

    Energy Technology Data Exchange (ETDEWEB)

    Iwase, A; Rehn, L E; Baldo, P M; Funk, L [Argonne National Lab., IL (United States). Materials Science Div.

    1997-03-01

    The effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-1%Au at 400degC during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400degC, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist. (author)

  17. Influence of membrane composition on its flexibility

    International Nuclear Information System (INIS)

    Gerbelli, B.B.; Teixeira da Silva, E.R.; Oliveira, C.L.P.; Oliveira, E.A.

    2012-01-01

    Full text: Lamellar phases and vesicles composed of lipids have been used as model systems to investigate biological process related to cell membrane as well as promising carriers for drugs and gene therapy. The composition of the membrane determines its three dimensional shape and its properties such as rigidity and compressibility which play an important role on membrane fusion, protein adhesion, interactions between proteins, etc. We present systematic study of a lamellar system composed mainly of lecithin which is a biocompatible phospholipid and simusol, which is a mixture of fatty acids that acts as a cosurfactant introducing flexibility to the membrane. Using X ray scattering we determine the lamellar periodicity as a function of the hydration for different formulations of the membrane; ranging from 100 % to 50 % mass fraction of lecithin. The X-ray spectra are fitted using a 4 Gaussian model [1]that allows us to determine the lamellar periodicity and the Caille parameter [2]. The ideal swelling law relating the membrane volume fraction (φ m ) to the lamellar periodicity (D) is given by φ m =δ m /D, where δ m is the thickness membrane, however, when steric interactions are dominant with respect to electrostatic and van der Waals interactions, deviations from this behavior are expected [3]. We present experimental data illustrating the swelling behavior for the membrane compositions and the respective behavior of the hydration limit, membrane Luzzati [4], of the Caille parameter and qualitative interpretation of the interaction forces the systems studying the parameter membrane square amplitude fluctuation[5]. [1] Private communication with Prof. Dr. Cristiano Luis Pinto de Oliveira. [2] Caille A. et all, Acad. Sci. Paris B274 (1972) 891. [3] E. Kurtisovski et all, PRL 98, 258103 (2007). [4] Nagle et all, Curr Opin Struct Biol. 2000 Aug;10(4):474-80. [5] H. I. Petrache. Structure and interactions of fluid phospholipids bilayers measured by high resolution

  18. Molecular organization in bacterial cell membranes. Specific labelling and topological distribution of glycoproteins and proteins in Streptomyces albus membranes

    Energy Technology Data Exchange (ETDEWEB)

    Larraga, V; Munoz, E [Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Instituto de Biologia Celular

    1975-05-01

    The paper reports about an investigation into the question of the specific labelling and topological distribution of glycoproteins and proteins in Streptomyces albus membranes. The method of sample preparation is described: Tritium labelling of glycoproteins in protoplasts and membranes, iodination of proteins, trypsin treatment and polyacrylamide gel electrophoresis. The findings suggest an asymmetrical distribution of the glycoproteins in membranes and a weak accessibility to iodine label. A structural model of the plasma membranes of Streptomyces albus is proposed similar to the general 'fluid mosaic' model of Singer and Nicholson.

  19. Combined use of radioiodine therapy and radiofrequency ablation in treating postsurgical thyroid remnant of differentiated thyroid carcinoma

    Directory of Open Access Journals (Sweden)

    Bin Long

    2015-01-01

    Conclusion: Combined use of RAI therapy and radiofrequency ablation in treating excessive postsurgical thyroid remnant of DTC can be an effective approach and avoids re-operation. Long-term efficacy monitoring would further determine its feasibility.

  20. Variation in diel activity of ground beetles (Coleoptera: Carabidae) associated with a soybean field and coal mine remnant

    Science.gov (United States)

    Willand, J.E.; McCravy, K.W.

    2006-01-01

    Diel activities of carabids (Coleoptera: Carabidae) associated with a coal mine remnant and surrounding soybean field were studied in west-central Illinois from June through October 2002. A total of 1,402 carabids, representing 29 species and 17 genera, were collected using pitfall traps. Poecilus chalcites (Say) demonstrated roughly equal diurnal and nocturnal activity in June, but greater diurnal activity thereafter. Pterostichus permundus (Say), Cyclotrachelus seximpressus (LeConte), Amara obesa (Say), and Scarites quadriceps Chaudoir showed significant nocturnal activity. Associations between habitat and diel activity were found for three species: P. chalcites associated with the remnant and edge habitats showed greater diurnal activity than those associated with the soybean field; C. seximpressus was most active diurnally in the remnant, and Harpalus pensylvanicus (DeGeer) showed the greatest nocturnal activity in the remnant and edge habitats. We found significant temporal and habitat-related variation in diel activity among carabid species inhabiting agricultural areas in west-central Illinois.

  1. Genetically elevated non-fasting triglycerides and calculated remnant cholesterol as causal risk factors for myocardial infarction

    DEFF Research Database (Denmark)

    Jørgensen, Anders Berg; Frikke-Schmidt, Ruth; West, Anders Sode

    2012-01-01

    AimsElevated non-fasting triglycerides mark elevated levels of remnant cholesterol. Using a Mendelian randomization approach, we tested whether genetically increased remnant cholesterol in hypertriglyceridaemia due to genetic variation in the apolipoprotein A5 gene (APOA5) associates with an incr......AimsElevated non-fasting triglycerides mark elevated levels of remnant cholesterol. Using a Mendelian randomization approach, we tested whether genetically increased remnant cholesterol in hypertriglyceridaemia due to genetic variation in the apolipoprotein A5 gene (APOA5) associates...... with an increased risk of myocardial infarction (MI).Methods and resultsWe resequenced the core promoter and coding regions of APOA5 in individuals with the lowest 1% (n = 95) and highest 2% (n = 190) triglyceride levels in the Copenhagen City Heart Study (CCHS, n = 10 391). Genetic variants which differed...... in frequency between the two extreme triglyceride groups (c.-1131T > C, S19W, and c.*31C > T; P-value: 0.06 to...

  2. FOREWORD Fluid Mechanics and Fluid Power (FMFP)

    Indian Academy of Sciences (India)

    This section of the Special Issue carries selected articles from the Fluid Mechanics and Fluid. Power Conference held during 12–14 December 2013 at the National Institute of Technology,. Hamirpur (HP). The section includes three review articles and nine original research articles. These were selected on the basis of their ...

  3. Are we headed towards the defaunation of the last large Atlantic Forest remnants? Poaching activities in one of the largest remnants of the Tabuleiro forests in southeastern Brazil.

    Science.gov (United States)

    Sousa, José Adelson C; Srbek-Araujo, Ana C

    2017-03-01

    Hunting is a problem to animal conservation in different parts of the world and it has caused the local extinction of several species. The aim of this study was to characterize the poaching activities in one of the main tabuleiro forest remnants of Brazil, the Linhares-Sooretama Block (LSB). Poaching records from 2010 to 2013 were gathered from the agencies responsible for monitoring and combating environmental crimes in the LSB. A total of 693 records (mean = 173 events/year) were collected involving direct (hunted animals, firearms, handmade firearms, traps, poachers, and various hunting supplies) and indirect (tree stands, baits, and poacher signs) evidences of poaching. No differences in the monthly cumulative number of records were found among years, but the distribution of records differed according to the type of evidence. A total of 40 animal seizure events were recorded involving a total of at least 15 taxa directly affected by poaching (reptiles = 2, birds = 6, mammals = 7) and 75 individuals seized (19 individuals/year). Five of the poached species are threatened. Lowland paca (Cuniculus paca) and armadillos were the most poached mammals in the region. Most of the poachers conduct such activities for fun (entertainment) and/or professionally (commercial hunting). The collected data show an approximately 32% increase in the number of poaching events in the region compared with the historical data available for LSB. It may have resulted from a gradual decrease in protection, both in terms of the number of agents deployed and the levels of effort of the teams, which began in 2009. The data demonstrate that poaching is a significant threat to the conservation of the LSB fauna, as it is in other Atlantic Forest remnants and in other regions of the world. Protection activities must be intensified to effectively combat the impacts of poaching in the LSB region, thereby contributing to the conservation of species in one of the few Atlantic Forest

  4. The hard X-ray view of the young supernova remnant G1.9+0.3

    DEFF Research Database (Denmark)

    Zoglauer, Andreas; Reynolds, Stephen P.; An, Hongjun

    2015-01-01

    NuSTAR observed G1.9+0.3, the youngest known supernova remnant in the Milky Way, for 350 ks and detected emission up to ~30 keV. The remnant's X-ray morphology does not change significantly across the energy range from 3 to 20 keV. A combined fit between NuSTAR and Chandra shows that the spectrum...

  5. Environmental effects of the Big Rapids dam remnant removal, Big Rapids, Michigan, 2000-02

    Science.gov (United States)

    Healy, Denis F.; Rheaume, Stephen J.; Simpson, J. Alan

    2003-01-01

    The U.S. Geological Survey (USGS), in cooperation with the city of Big Rapids, investigated the environmental effects of removal of a dam-foundation remnant and downstream cofferdam from the Muskegon River in Big Rapids, Mich. The USGS applied a multidiscipline approach, which determined the water quality, sediment character, and stream habitat before and after dam removal. Continuous water-quality data and discrete water-quality samples were collected, the movement of suspended and bed sediment were measured, changes in stream habitat were assessed, and streambed elevations were surveyed. Analyses of water upstream and downstream from the dam showed that the dam-foundation remnant did not affect water quality. Dissolved-oxygen concentrations downstream from the dam remnant were depressed for a short period (days) during the beginning of the dam removal, in part because of that removal effort. Sediment transport from July 2000 through March 2002 was 13,800 cubic yards more at the downstream site than the upstream site. This increase in sediment represents the remobilized sediment upstream from the dam, bank erosion when the impoundment was lowered, and contributions from small tributaries between the sites. Five habitat reaches were monitored before and after dam-remnant removal. The reaches consisted of a reference reach (A), upstream from the effects of the impoundment; the impoundment (B); and three sites below the impoundment where habitat changes were expected (C, D, and E, in downstream order). Stream-habitat assessment reaches varied in their responses to the dam-remnant removal. Reference reach A was not affected. In impoundment reach B, Great Lakes and Environmental Assessment Section (GLEAS) Procedure 51 ratings went from fair to excellent. For the three downstream reaches, reach C underwent slight habitat degradation, but ratings remained good; reach D underwent slight habitat degradation with ratings changing from excellent to good; and, in an area

  6. Formation of carrageenan-CaCO{sub 3} bioactive membranes

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Lucas F.B.; Maniglia, Bianca C.; Pereira, Lourivaldo S.; Tapia-Blácido, Delia R.; Ramos, Ana P., E-mail: anapr@ffclrp.usp.br

    2016-01-01

    The high biocompatibility and resorbability of polymeric membranes have encouraged their use to manufacture medical devices. Here, we report on the preparation of membranes consisting of carrageenan, a naturally occurring sulfated polysaccharide that forms helical structures in the presence of calcium ions. We incorporated CaCO{sub 3} particles into the membranes to enhance their bioactivity and mechanical properties. Infrared spectroscopy and X-ray diffraction data confirmed CaCO{sub 3} incorporation into the polymeric matrix. We tested the bioactivity of the samples by immersing them in a solution that mimics the ionic composition and pH of the human body fluid. The hybrid membranes generated hydroxyapatite, as attested by X-ray diffraction data. Scanning electron and atomic force microscopies aided investigation of membrane topography before and after CaCO{sub 3} deposition. The wettability and surface free energy, evaluated by contact angle measures, increased in the presence of CaCO{sub 3} particles. These parameters are important for membrane implantation in the body. Moreover, membrane stiffness was up to 110% higher in the presence of the inorganic particles, as revealed by Young's modulus. - Highlights: • Hybrid kappa and iota carrageenan-CaCO{sub 3} membranes were formed. • The hybrid membrane's origin hydroxyapatite after exposure to simulated body fluid • The carrageenan's specificity to bind Ca{sup 2+} ions tailors the surface properties.

  7. Lectures on fluid mechanics

    CERN Document Server

    Shinbrot, Marvin

    2012-01-01

    Readable and user-friendly, this high-level introduction explores the derivation of the equations of fluid motion from statistical mechanics, classical theory, and a portion of the modern mathematical theory of viscous, incompressible fluids. 1973 edition.

  8. Synovial Fluid Analysis

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... is being tested? Synovial fluid is a thick liquid that acts as a lubricant for the body's ...

  9. Electric fluid pump

    Science.gov (United States)

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  10. Cerebrospinal fluid culture

    Science.gov (United States)

    ... Alternative Names Culture - CSF; Spinal fluid culture; CSF culture Images Pneumococci organism References Karcher DS, McPherson RA. Cerebrospinal, synovial, serous body fluids, and alternative specimens. In: McPherson RA, Pincus ...

  11. Cerebrospinal fluid leak (image)

    Science.gov (United States)

    ... brain and spinal cord by acting like a liquid cushion. The fluid allows the organs to be buoyant protecting them from blows or other trauma. Inside the skull the cerebrospinal fluid is contained by the dura which covers ...

  12. Computational Fluid Dynamics

    International Nuclear Information System (INIS)

    Myeong, Hyeon Guk

    1999-06-01

    This book deals with computational fluid dynamics with basic and history of numerical fluid dynamics, introduction of finite volume method using one-dimensional heat conduction equation, solution of two-dimensional heat conduction equation, solution of Navier-Stokes equation, fluid with heat transport, turbulent flow and turbulent model, Navier-Stokes solution by generalized coordinate system such as coordinate conversion, conversion of basic equation, program and example of calculation, application of abnormal problem and high speed solution of numerical fluid dynamics.

  13. In-vitro Degradation Behaviour of Irradiated Bacterial Cellulose Membrane

    International Nuclear Information System (INIS)

    Darwis, D.; Khusniya, T.; Hardiningsih, L.; Nurlidar, F.; Winarno, H.

    2012-01-01

    Bacterial cellulose membrane synthesized by Acetobacter xylinum in coconut water medium has potential application for Guided bone Regeneration. However, this membrane may not meet some application requirements due to its low biodegradation properties. In this paper, incorporation of gamma irradiation into the membrane is a developed strategy to increase its biodegradability properties. The in-vitro degradation study in synthetic body fluid (SBF) of the irradiated membrane has been analyzed during periods of 6 months by means of weight loss, mechanical properties and scanning electron microscopy observation compared to that the un-irradiated one. The result showed that weight loss of irradiated membrane with 25 kGy and 50 kGy and immersed in SBF solution for 6 months reached 18% and 25% respectively. While un-irradiated membrane did not give significant weight loss. Tensile strength of membranes decreases with increasing of irradiation dose and further decreases in tensile strength is observed when irradiated membrane was followed by immersion in SBF solution. Microscope electron image of cellulose membranes shows that un-irradiated bacterial cellulose membrane consists of dense ultrafine fibril network structures, while irradiation result in cleavage of fibrils network of cellulose. The fibrils network become loosely after irradiated membrane immersed in SBF solution due to released of small molecular weight carbohydrates formed during by irradiation from the structure (author)

  14. Stellar remnants

    CERN Document Server

    Kawaler, S D; Srinivasan, G

    1997-01-01

    This volume examines the internal structure, origin and evolution of white dwarfs, neutron stars and black holes, all objects at the final stage of stellar evolution. It covers topics such as: pulsation of white dwarfs; millisecond pulsars; and the dynamics around black holes.

  15. Fluid Statics and Archimedes

    Indian Academy of Sciences (India)

    librium of a vertical slice fluid (Figure Id) of height H and again using the fact .... same fluid having the same shape and same volume as the body. This fluid volume .... example, can be caused by the heating of air near the ground by the sun ...

  16. Fullerol ionic fluids

    KAUST Repository

    Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

    2010-01-01

    ®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding

  17. Does remnant gastric cancer really differ from primary gastric cancer? A systematic review of the literature by the Task Force of Japanese Gastric Cancer Association.

    Science.gov (United States)

    Shimada, Hideaki; Fukagawa, Takeo; Haga, Yoshio; Oba, Koji

    2016-04-01

    Remnant gastric cancer, most frequently defined as cancer detected in the remnant stomach after distal gastrectomy for benign disease and those cases after surgery of gastric cancer at least 5 years after the primary surgery, is often reported as a tumor with poor prognosis. The Task Force of Japanese Gastric Cancer Association for Research Promotion evaluated the clinical impact of remnant gastric cancer by systematically reviewing publications focusing on molecular carcinogenesis, lymph node status, patient survival, and surgical complications. A systematic literature search was performed using PubMed/MEDLINE with the keywords "remnant," "stomach," and "cancer," revealing 1154 relevant reports published up to the end of December 2014. The mean interval between the initial surgery and the diagnosis of remnant gastric cancer ranged from 10 to 30 years. The incidence of lymph node metastases at the splenic hilum for remnant gastric cancer is not significantly higher than that for primary proximal gastric cancer. Lymph node involvement in the jejunal mesentery is a phenomenon peculiar to remnant gastric cancer after Billroth II reconstruction. Prognosis and postoperative morbidity and mortality rates seem to be comparable to those for primary proximal gastric cancer. The crude 5-year mortality for remnant gastric cancer was 1.08 times higher than that for primary proximal gastric cancer, but this difference was not statistically significant. In conclusion, although no prospective cohort study has yet evaluated the clinical significance of remnant gastric cancer, our literature review suggests that remnant gastric cancer does not adversely affect patient prognosis and postoperative course.

  18. Fluid and particle mechanics

    CERN Document Server

    Michell, S J

    2013-01-01

    Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th

  19. Fluid inclusion geothermometry

    Science.gov (United States)

    Cunningham, C.G.

    1977-01-01

    Fluid inclusions trapped within crystals either during growth or at a later time provide many clues to the histories of rocks and ores. Estimates of fluid-inclusion homogenization temperature and density can be obtained using a petrographic microscope with thin sections, and they can be refined using heating and freezing stages. Fluid inclusion studies, used in conjunction with paragenetic studies, can provide direct data on the time and space variations of parameters such as temperature, pressure, density, and composition of fluids in geologic environments. Changes in these parameters directly affect the fugacity, composition, and pH of fluids, thus directly influencing localization of ore metals. ?? 1977 Ferdinand Enke Verlag Stuttgart.

  20. Fluid Mechanics and Fluid Power (FMFP)

    Indian Academy of Sciences (India)

    Amitabh Bhattacharya

    of renewable energy (e.g., via wind, hydrokinetic generators), creating low-cost healthcare ... multiphase flow, turbulence, bio-fluid dynamics, atmospheric flows, microfluidic flows, and ... study the challenging problem of entry of solids in water.

  1. Spectroscopic mapping of the physical properties of supernova remnant N 49

    Science.gov (United States)

    Pauletti, D.; Copetti, M. V. F.

    2016-10-01

    Context. Physical conditions inside a supernova remnant can vary significantly between different positions. However, typical observational data of supernova remnants are integrated data or contemplate specific portions of the remnant. Aims: We study the spatial variation in the physical properties of the N 49 supernova remnant based on a spectroscopic mapping of the whole nebula. Methods: Long-slit spectra were obtained with the slit (~4' × 1.03″) aligned along the east-west direction from 29 different positions spaced by 2″ in declination. A total of 3248 1D spectra were extracted from sections of 2″ of the 2D spectra. More than 60 emission lines in the range 3550 Å to 8920 Å were measured in these spectra. Maps of the fluxes and of intensity ratios of these emission lines were built with a spatial resolution of 2″ × 2″. Results: An electron density map has been obtained using the [S II] λ6716 /λ6731 line ratio. Values vary from ~500 cm-3 at the northeast region to more than 3500 cm-3 at the southeast border. We calculated the electron temperature using line ratio sensors for the ions S+, O++, O+, and N+. Values are about 3.6 × 104 K for the O++ sensor and about 1.1 × 104 K for other sensors. The Hα/Hβ ratio map presents a ring structure with higher values that may result from collisional excitation of hydrogen. We detected an area with high values of [N II] λ6583/Hα extending from the remnant center to its northeastern border, which may be indicating an overabundance of nitrogen in the area due to contamination by the progenitor star. We found a radial dependence in many line intensity ratio maps. We observed an increase toward the remnant borders of the intensity ratio of any two lines in which the numerator comes before in the sequence [O III] λ5007, [O III] λ4363, [Ar III] λ7136, [Ne III] λ3869, [O II] λ7325, [O II] λ3727, He II λ4686, Hβ λ4861, [N II] λ6583, He I λ6678, [S II] λ6731, [S II] λ6716, [O I] λ6300, [Ca II]

  2. Removal of Retained Adherent Placental Remnants Using the Hysteroscopy Endo-Operative System.

    Science.gov (United States)

    Zhu, Ke-An; Huang, Huan; Xue, Min; Subedi, Jigyasa; Jamail, Grace; Zhao, Weidong; Xu, Dabao; Xiao, Songshu

    2016-01-01

    Removal of retained adherent placental remnants (RAPRs) may be challenging using traditional 5Fr or 7Fr hysteroscopic grasping forceps because they are very small. This is particularly true when the retained placental remnant is large. This video demonstrates the advantages of using the Hysteroscopy Endo-Operative System (HEOS), a specially designed operative hysteroscope with a 13Fr working channel, to remove retained placental remnants. Step-by-step explanation of the technique using videos and pictures (educative video) (Canadian Task Force Classification III). Third Xiangya Hospital of Central South University, Hunan, China. A 32-year-old woman was diagnosed with RAPRs 5 weeks after the evacuation of retained placenta after a spontaneous abortion at 16 weeks' gestation. Gynecologic examination revealed an anterior 8-week uterus and no tenderness. Serum β-human chorionic gonadotropin was 150 mIU/L. Sonography revealed an irregular intrauterine mass, 3.5 cm × 3.5 cm × 3 cm in size. Removal of RAPRs using HEOS (Sopro-comeg Company, Bordeaux, France). The operation time was only 12 minutes. The RAPRs were removed completely and quickly in 1 procedure with no complications. The serum β-human chorionic gonadotropin titer normalized 1 week after the procedure. This study was approved by the institutional review board of the Third Xiangya Hospital of Central South University. When indicated, removal of RAPRs using HEOS is safe and simple because of its large and strong cold forceps. Additionally, it avoids electrical and thermal injury to the endometrium, which is particularly important in a population that wants to preserve fertility. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

  3. Mass Ejection from the Remnant of a Binary Neutron Star Merger: Viscous-radiation Hydrodynamics Study

    Science.gov (United States)

    Fujibayashi, Sho; Kiuchi, Kenta; Nishimura, Nobuya; Sekiguchi, Yuichiro; Shibata, Masaru

    2018-06-01

    We perform long-term general relativistic neutrino radiation hydrodynamics simulations (in axisymmetry) for a massive neutron star (MNS) surrounded by a torus, which is a canonical remnant formed after the binary neutron star merger. We take into account the effects of viscosity, which is likely to arise in the merger remnant due to magnetohydrodynamical turbulence. The viscous effect plays key roles for the mass ejection from the remnant in two phases of the evolution. In the first t ≲ 10 ms, a differential rotation state of the MNS is changed to a rigidly rotating state. A shock wave caused by the variation of its quasi-equilibrium state induces significant mass ejection of mass ∼(0.5–2.0) × {10}-2 {M}ȯ for the α-viscosity parameter of 0.01–0.04. For the longer-term evolution with ∼0.1–10 s, a significant fraction of the torus material is ejected. We find that the total mass of the viscosity-driven ejecta (≳ {10}-2 {M}ȯ ) could dominate over that of the dynamical ejecta (≲ {10}-2 {M}ȯ ). The electron fraction, Y e , of the ejecta is always high enough (Y e ≳ 0.25) that this post-merger ejecta is lanthanide-poor; hence, the opacity of the ejecta is likely to be ∼10–100 times lower than that of the dynamical ejecta. This indicates that the electromagnetic signal from the ejecta would be rapidly evolving, bright, and blue if it is observed from a small viewing angle (≲45°) for which the effect of the dynamical ejecta is minor.

  4. EVOLUTION OF HIGH-ENERGY PARTICLE DISTRIBUTION IN MATURE SHELL-TYPE SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Houdun; Xin, Yuliang; Liu, Siming; Zhang, Shuinai [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Jokipii, J. R. [University of Arizona, Tucson, Arizona, 85721 (United States); Zhang, Li, E-mail: zhd@pmo.ac.cn, E-mail: liusm@pmo.ac.cn [Key Laboratory of Astroparticle Physics of Yunnan Province, Kunming, 650091 (China)

    2017-01-10

    Multi-wavelength observations of mature supernova remnants (SNRs), especially with recent advances in γ -ray astronomy, make it possible to constrain energy distribution of energetic particles within these remnants. In consideration of the SNR origin of Galactic cosmic rays and physics related to particle acceleration and radiative processes, we use a simple one-zone model to fit the nonthermal emission spectra of three shell-type SNRs located within 2° on the sky: RX J1713.7−3946, CTB 37B, and CTB 37A. Although radio images of these three sources all show a shell (or half-shell) structure, their radio, X-ray, and γ -ray spectra are quite different, offering an ideal case to explore evolution of energetic particle distribution in SNRs. Our spectral fitting shows that (1) the particle distribution becomes harder with aging of these SNRs, implying a continuous acceleration process, and the particle distributions of CTB 37A and CTB 37B in the GeV range are harder than the hardest distribution that can be produced at a shock via the linear diffusive shock particle acceleration process, so spatial transport may play a role; (2) the energy loss timescale of electrons at the high-energy cutoff due to synchrotron radiation appears to be always a bit (within a factor of a few) shorter than the age of the corresponding remnant, which also requires continuous particle acceleration; (3) double power-law distributions are needed to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock interaction with molecular clouds.

  5. Removal of foreskin remnants in circumcised adults for treatment of premature ejaculation

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Namavar

    2011-01-01

    Full Text Available Background and Aim : Premature ejaculation (PE is the most prevalent sexual dysfunction in every country. There are many types of treatment, but the main limitation of medical treatment for premature ejaculation is recurrence after withdrawal of medicine. The prepuce is a specific erogenous zone that contains a rich and complex network of nerves. Circumcision radically desensitizes the penis, but incomplete circumcision may cause premature ejaculation. We evaluate the effect of removal of foreskin remnants in adults on PE. Materials and Methods : The sensitive area of penile skin and the remaining parts of foreskin in adult men were recognized in 47 selective patients. Under local anesthesia, the remnant parts of foreskin were incised and removed. They were asked to fill the investigating questionnaire about the changes of intravaginal latency ejaculatory time (IVELT, patients and their sexual partners′ satisfaction with sexual life, control over ejaculation, and penile sensitivity, before and after treatment. Results : There were no signs of inflammation and no serious adverse reactions in all cases after operation. IVELT significantly increased from 64.25 before surgery to 731.49 sec after surgery (P<0.001. The percentage of postoperative satisfaction in both the patient and his partner significantly increased (P<0.001. After surgery, 95.7% of men had better control over their ejaculation. This surgery significantly decreased sensitivity of penis (P<0.001, but it did not change glans penis insensitivity. Conclusions : These results indicate that removal of foreskin remnants in adults is an effective modality in selective patients of PE.

  6. GW170817 and the Prospect of Forming Supramassive Remnants in Neutron Star Mergers

    Science.gov (United States)

    Ma, Peng-Xiong; Jiang, Jin-Liang; Wang, Hao; Jin, Zhi-Ping; Fan, Yi-Zhong; Wei, Da-Ming

    2018-05-01

    The gravitational wave data of GW170817 favor the equation of state (EoS) models that predict compact neutron stars (NSs), consistent with the radius constraints from X-ray observations. Motivated by such remarkable progress, we examine the fate of the remnants formed in NS mergers and focus on the roles of the angular momentum and the mass distribution of the binary NSs. In the mass-shedding limit (for which the dimensionless angular momentum equals the Keplerian value, i.e., j = j Kep), the adopted seven EoS models, except for H4 and ALF2, yield supramassive NSs in more than half of the mergers. However, for j ≲ 0.7 j Kep, the presence or absence of a non-negligible fraction of supramassive NSs formed in the mergers depends sensitively on both the EoS and the mass distribution of the binary systems. The NS mergers with a total gravitational mass ≤ 2.6 M ⊙ are found to be able to shed valuable light on both the EoS model and the angular momentum of the remnants if supramassive NSs are still absent. We have also discussed the uncertainty on estimating the maximum gravitational mass of nonrotating NSs (M max) due to the unknown j of the precollapse remnants. With the data of GW170817 and the assumption of the mass loss of 0.03 M ⊙, we have M max < (2.19, 2.32) M ⊙ (90% confidence level) for j = (1.0, 0.8) j Kep, respectively.

  7. Paleoenvironmental analyses of an organic deposit from an erosional landscape remnant, Arctic Coastal Plain of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Eisner, W R; Bockheim, J G; Hinkel, K M; Brown, T A; Nelson, F E; Peterson, K M; Jones, B M

    2005-01-02

    The dominant landscape process on the Arctic Coastal Plain of northern Alaska is the formation and drainage of thaw lakes. Lakes and drained thaw lake basins account for approximately 75% of the modern surface expression of the Barrow Peninsula. The thaw lake cycle usually obliterates lacustrine or peat sediments from previous cycles which could otherwise be used for paleoecological reconstruction of long-term landscape and vegetation changes. Several possible erosional remnants of a former topographic surface that predates the formation of the thaw lakes have been tentatively identified. These remnants are characterized by a higher elevation, a thick organic layer with very high ground ice content in the upper permafrost, and a plant community somewhat atypical of the region. Ten soil cores were collected from one site, and one core was intensively sampled for soil organic carbon content, pollen analysis, and {sup 14}C dating. The lowest level of the organic sediments represents the earliest phase of plant growth and dates to ca. 9000 cal BP. Palynological evidence indicates the presence of mesic shrub tundra (including sedge, birch, willow, and heath vegetation); and microfossil indicators point to wetter eutrophic conditions during this period. Carbon accumulation was rapid due to high net primary productivity in a relatively nutrient-rich environment. These results are interpreted as the local response to ameliorating climate during the early Holocene. The middle Holocene portion of the record contains an unconformity, indicating that between 8200 and 4200 cal BP sediments were eroded from the site, presumably in response to wind activity during a drier period centered around 4500 cal BP. The modern vegetation community of the erosional remnant was established after 4200 cal BP, and peat growth resumed. During the late Holocene, carbon accumulation rates were greatly reduced in response to the combined effects of declining productivity associated with climatic

  8. Wind dispersal of alien plant species into remnant natural vegetation from adjacent agricultural fields

    Directory of Open Access Journals (Sweden)

    Chika Egawa

    2017-07-01

    Full Text Available Knowledge regarding the seed dispersal of alien species is crucial to manage invasion risk in fragmented natural habitats. Focusing on wind dispersal, this study assessed the spatial and quantitative extents to which a remnant natural fen receives the seeds of alien species dispersed from adjacent hay meadows in Hokkaido, northern Japan. I established a total of 80 funnel seed traps in the fen at distances of 1, 2, 5, 10, 20, 30, 50, and 100 m from the meadows. The proportion of alien species in the seed rain at each distance was quantified, and the 99th-percentile dispersal distance from the meadows was estimated for each alien species by constructing dispersal kernels. Despite the presence of a marginal ditch and an elevational difference between the fen and the meadows, five alien species, including four grasses that do not have modified seed structures for wind dispersal, dispersed their seeds into the fen. These alien species accounted for up to 65.9% of the seed rain in terms of quantity. The 99th-percentile dispersal distances of the alien species ranged from 3.8 m to 309.3 m, and these distances were longer than the values predicted on the basis of their functional traits, such as terminal velocity. The results of this study demonstrated that numerous seeds of farmland-derived alien species were transported into the remnant vegetation via wind dispersal, and that simple predictions of dispersal distance based on functional traits could underestimate the potential area that alien species can reach. Continuous management both in farmland (to reduce seed escape and in remnant vegetation (to prevent the establishment of alien species is necessary to protect native vegetation from biological invasion in agricultural landscapes.

  9. Fish remnants from the excavations of the Bronze Age barrow near Maryanskoe village (Dnepropetrovsk region, Ukraine

    Directory of Open Access Journals (Sweden)

    O. M. Kovalchuk

    2014-10-01

    Full Text Available The Bronze Age mound (2.5–2.3 kya BC is located near the Maryanskoe village (Apostolovskyi district, Dnepropetrovsk region and was excavated in 1953. The results of determination of the fish remnants, which were found during the excavation, are presented in the paper. Eleven species belonging to 9 genera, 5 families and 5 orders (Acipenseriformes, Cypriniformes, Siluriformes, Esociformes, Perciformes were identified: russian sturgeon Acipenser gueldenstaedtii Brandt et Ratzeburg, 1833, stellate sturgeon A. stellatus Pallas, 1771, common ide Idus idus (Linnaeus, 1758, common roach Rutilus rutilus (Linnaeus, 1758, pontic roach R. frisii (Nordmann, 1840, common bream Abramis brama (Linnaeus, 1758, common carp Cyprinus carpio Linnaeus, 1758, tench Tinca tinca (Linnaeus, 1758, european catfish Silurus glanis Linnaeus, 1758, northern pike Esox lucius (Linnaeus, 1758, and zander Sander lucioperca (Linnaeus, 1758. Most of them are quite common in the Dnieper river basin. It was found that carp fishes predominate in the number of species. Most of the bone remnants in the collection belong to zander, catfish and pike, while common roach, pontic roach and common bream are identified by the few bones. This may indicate a different role of these species in the diet of the local population. The ratio of skeletal elements in the collection is the evidence of the fish cutting on the site. Body length and weight was reconstructed for 64 fish specimens. It was found that they were mature and small-sized, except for catfish, pike and perch. Taking into account the characteristics of the funeral rituals of the Yamna culture population, fish bones from the mound near Maryanskoe can be remnants of the parting meal.

  10. Empagliflozin decreases remnant-like particle cholesterol in type 2 diabetes patients with insulin resistance.

    Science.gov (United States)

    Hattori, Sachiko

    2017-11-28

    Remnant lipoproteins are thought to be atherogenic. Remnant-like particle cholesterol (RLP-C), which reflects the levels of various kinds of remnant lipoproteins in the blood, has a significant correlation with insulin resistance. In the present study, we measured the effect of empagliflozin (EMPA) on the levels of RLP-C, and investigated whether EMPA-mediated change in RLP-C is associated with a change in insulin resistance in type 2 diabetes patients who have insulin resistance. Patients were allocated to receive a placebo (n = 51) or EMPA (n = 58) as an add-on treatment. Fasting blood samples were collected before and 12 weeks after this intervention. EMPA significantly decreased glycated hemoglobin, bodyweight, systolic blood pressure, plasma triglycerides, liver transaminases and estimated glomerular filtration rate, and increased high-density lipoprotein cholesterol. Furthermore, EMPA decreased RLP-C and homeostatic model assessment of insulin resistance. In the placebo group, there were no significant changes in these factors except for slight increases in liver transaminases. Multiple regression analysis showed that the change in homeostatic model assessment of insulin resistance (P = 0.0102) and the change in alanine aminotransferase (P = 0.0301) were significantly associated with the change in RLP-C in the EMPA group. The change in RLP-C significantly correlated with the change in homeostatic model assessment of insulin resistance (Pearson correlation coefficient 0.503, 95% confidence interval 0.199-0.719; P = 0.00241). EMPA decreases RLP-C levels, which is closely associated with amelioration of insulin sensitivity in diabetes patients who have insulin resistance. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  11. Cosmological horizons as new examples of the membrane paradigm

    International Nuclear Information System (INIS)

    Wang, Tower

    2015-01-01

    In this paper we aim to provide new examples of the application and the generality of the membrane paradigm. The membrane paradigm is a formalism for studying the event horizon of black holes. After analyzing it with some technical details and realizing it in the Reissner–Nordström black hole, we apply the paradigm to cosmological horizons, first to the pure de Sitter horizon, and then to the trapping horizon of the Friedmann–Lemaître–Robertson–Walker Universe. In the latter case, the cosmological stretched horizon is oblique, thus the running of the renormalization parameter is nonzero in the timelike direction and gives a correction to the membrane pressure. In this paradigm, the cosmological equations come from continuity equations of the membrane fluid and the bulk fluid respectively. (paper)

  12. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T [Huntington Beach, CA; Sahimi, Muhammad [Altadena, CA; Fayyaz-Najafi, Babak [Richmond, CA; Harale, Aadesh [Los Angeles, CA; Park, Byoung-Gi [Yeosu, KR; Liu, Paul K. T. [Lafayette Hill, PA

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  13. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  14. Membrane with integrated spacer

    NARCIS (Netherlands)

    Balster, J.H.; Stamatialis, Dimitrios; Wessling, Matthias

    2010-01-01

    Many membrane processes are severely influenced by concentration polarisation. Turbulence promoting spacers placed in between the membranes can reduce the diffusional resistance of concentration polarisation by inducing additional mixing. Electrodialysis (ED) used for desalination suffers from

  15. Temporary ovarian failure in thyroid cancer patients after thyroid remnant ablation with radioactive iodine

    International Nuclear Information System (INIS)

    Raymond, J.P.; Izembart, M.; Marliac, V.; Dagousset, F.; Merceron, R.E.; Vulpillat, M.; Vallee, G.

    1989-01-01

    We studied ovarian function retrospectively in 66 women who had regular menstrual cycles before undergoing complete thyroidectomy for differentiated thyroid cancer and subsequent thyroid remnant ablation with 131 I. Eighteen women developed temporary amenorrhea accompanied by increased serum gonadotropin concentrations during the first year after 131 I therapy. No correlation was found between the radioactive iodine dose absorbed, thyroid uptake before treatment, oral contraceptive use, or thyroid autoimmunity. Only age was a determining factor, with the older women being the most affected. We conclude that radioiodine ablation therapy is followed by transient ovarian failure, especially in older women

  16. The Atomic Physics of Fe K alpha: Toward Accurate Abundance Diagnostics for Supernova Remnants

    Science.gov (United States)

    Brickhouse, Nancy

    2009-09-01

    We propose to conduct a case study of Fe XVI K alpha emission produced during the transient ionization of a supernova remnant. This study includes critical evaluation of the existing data for electron impact inner-shell ionization and fluorescence yields, including tests conducted using a variety of theoretical atomic physics methods. Standard and newly developed atomic codes will be used. Once error estimates for the atomic data are complete, we will propagate these errors using the APEC code to simulate spectra and determine the overall accuracy of iron abundances determined from X-ray spectra.

  17. Scandinavian object shift, remnant VP-topicalisation, verb particles and causatives

    DEFF Research Database (Denmark)

    Engels, Eva; Vikner, Sten

    2013-01-01

    constructions in Danish and Swedish, namely particle verb constructions and causative constructions with Danish "lade" and Swedish "låta" ‘let’. It is shown how differences in the VP-internal object position give rise to mirror image sequences concerning Object Shift in connection with verb second (Vº......On the basis of an examination of remnant VP-topicalisation constructions, this paper argues for an order preservation analysis of Scandinavian Object Shift. Extending the empirical database, we account for the phenomena in an Optimality Theoretic framework. The paper focusses on two particular...

  18. Remnants of semiclassical bistability in the few-photon regime of cavity QED.

    Science.gov (United States)

    Kerckhoff, Joseph; Armen, Michael A; Mabuchi, Hideo

    2011-11-21

    Broadband homodyne detection of the light transmitted by a Fabry-Perot cavity containing a strongly-coupled (133)Cs atom is used to probe the dynamic optical response in a regime where semiclassical theory predicts bistability but strong quantum corrections should apply. While quantum fluctuations destabilize true equilibrium bistability, our observations confirm the existence of metastable states with finite lifetimes and a hysteretic response is apparent when the optical drive is modulated on comparable timescales. Our experiment elucidates remnant semiclassical behavior in the attojoule (~10 photon) regime of single-atom cavity QED, of potential significance for ultra-low power photonic signal processing. © 2011 Optical Society of America

  19. Soft x-ray emission from the Lupus Loop and SN 1006 supernova remnants

    International Nuclear Information System (INIS)

    Winkler, P.F. Jr.; Hearn, D.R.; Richardson, J.A.; Behnken, J.M.

    1979-01-01

    X-ray maps of the Lupus region have been obtained in a raster scan observation from SAS 3. These show the Lupus Loop to be a faint, extended source of soft x-rays with a temperature about 2.5 x 10 6 K. The most prominent feature of the region is the A.D. 1006 supernova remnant, which is unexpectedly bright at 0.2--1.0 keV. One speculative interpretation of the low-energy flux from SN 1006 is as blackbody radiation from a hot neutron star

  20. Temporary ovarian failure in thyroid cancer patients after thyroid remnant ablation with radioactive iodine

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, J.P.; Izembart, M.; Marliac, V.; Dagousset, F.; Merceron, R.E.; Vulpillat, M.; Vallee, G.

    1989-07-01

    We studied ovarian function retrospectively in 66 women who had regular menstrual cycles before undergoing complete thyroidectomy for differentiated thyroid cancer and subsequent thyroid remnant ablation with /sup 131/I. Eighteen women developed temporary amenorrhea accompanied by increased serum gonadotropin concentrations during the first year after /sup 131/I therapy. No correlation was found between the radioactive iodine dose absorbed, thyroid uptake before treatment, oral contraceptive use, or thyroid autoimmunity. Only age was a determining factor, with the older women being the most affected. We conclude that radioiodine ablation therapy is followed by transient ovarian failure, especially in older women.