WorldWideScience

Sample records for aao tubular membranes

  1. Magnetoresistive multilayers deposited on the AAO membranes

    Malkinski, Leszek M. [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States)]. E-mail: lmalkins@uno.edu; Chalastaras, Athanasios [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States); Vovk, Andriy [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States); Jung, Jin-Seung [Department of Chemistry, Kangnung National University, Kangnung 210702 (Korea, Republic of) ; Kim, Eun-Mee [Department of Chemistry, Kangnung National University, Kangnung 210702 (Korea, Republic of) ; Jun, Jong-Ho [Department of Applied Chemistry, Kunkuk University, Chungju 151747 (Korea, Republic of) ; Ventrice, Carl A. [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States)

    2005-02-01

    Silicon and GaAs wafers are the most commonly used substrates for deposition of giant magnetoresistive (GMR) multilayers. We explored a new type of a substrate, prepared electrochemically by anodization of aluminum sheets, for deposition of GMR multilayers. The surface of this AAO substrate consists of nanosized hemispheres organized in a regular hexagonal array. The current applied along the substrate surface intersects many magnetic layers in the multilayered structure, which results in enhancement of giant magnetoresistance effect. The GMR effect in uncoupled Co/Cu multilayers was significantly larger than the magnetoresistance of similar structures deposited on Si.

  2. Fabrication and characterization of nanostructured Mg-doped CdS/AAO nanoporous membrane for sensing applications

    Shaban, Mohamed; Mustafa, Mona; Hamdy, Hany

    2016-04-01

    In this study, Mg-doped CdS nanostructure was deposited onto anodic aluminum oxide (AAO) membrane substrate using sol-gel spin coating method. The AAO membrane was prepared by a two-step anodization process combined with pore widening process. The morphology, chemical composition, and structure of the spin- coated CdS nanostructure have been studied. The morphology of the fabricated AAO membrane and the deposited Mg-doped CdS nanostructure was investigated using scanning electron microscopy (SEM). The SEM of AAO illustrates a typical hexagonal and smooth nanoporous alumina membrane with interpore distance of ~ 100 nm, the pore diameter of ~ 60 nm. SEM of Mgdoped CdS shows porous nanostructured film of CdS nanoparticles. This film well adherents and covers the AAO substrate. The energy dispersive X-ray (EDX) pattern exhibits the signals of Al, O from AAO membrane and Mg, Cd, and S from the deposited CdS. This indicates the high purity of the fabricated membrane and the deposited Mg-doped CdS nanostructure. Using X-ray diffraction (XRD) pattern, Scherrer equation was used to calculate the average crystallite size. Additionally, the texture coefficients and density of dislocations were calculated. The fabricated CdS/AAO was applied to detect glucose of different concentrations. The proposed method has some advantages such as simple technology, low cost of processing, and high throughput. All of these factors facilitate the use of the prepared films in sensing applications.

  3. Tubular Membrane Plant-Growth Unit

    Dreschel, Thomas W.

    1992-01-01

    Hydroponic system controls nutrient solution for growing crops in space. Pump draws nutrient solution along inside of tubular membrane in pipe from reservoir, maintaining negative pressure in pipe. Roots of plants in slot extract nutrient through membrane within pipe. Crop plants such as wheat, rice, lettuce, tomatoes, soybeans, and beans grown successfully with system.

  4. A tunable sub-100 nm silicon nanopore array with an AAO membrane mask: reducing unwanted surface etching by introducing a PMMA interlayer

    Lim, Namsoo; Pak, Yusin; Kim, Jin Tae; Hwang, Youngkyu; Lee, Ryeri; Kumaresan, Yogeenth; Myoung, Nosoung; Ko, Heung Cho; Jung, Gun Young

    2015-08-01

    Highly ordered silicon (Si) nanopores with a tunable sub-100 nm diameter were fabricated by a CF4 plasma etching process using an anodic aluminum oxide (AAO) membrane as an etching mask. To enhance the conformal contact of the AAO membrane mask to the underlying Si substrate, poly(methyl methacrylate) (PMMA) was spin-coated on top of the Si substrate prior to the transfer of the AAO membrane. The AAO membrane mask was fabricated by two-step anodization and subsequent removal of the aluminum support and the barrier layer, which was then transferred to the PMMA-coated Si substrate. Contact printing was performed on the sample with a pressure of 50 psi and a temperature of 120 °C to make a conformal contact of the AAO membrane mask to the Si substrate. The CF4 plasma etching was conducted to transfer nanopores onto the Si substrate through the PMMA interlayer. The introduced PMMA interlayer prevented unwanted surface etching of the Si substrate by eliminating the etching ions and radicals bouncing at the gap between the mask and the substrate, resulting in a smooth Si nanopore array.Highly ordered silicon (Si) nanopores with a tunable sub-100 nm diameter were fabricated by a CF4 plasma etching process using an anodic aluminum oxide (AAO) membrane as an etching mask. To enhance the conformal contact of the AAO membrane mask to the underlying Si substrate, poly(methyl methacrylate) (PMMA) was spin-coated on top of the Si substrate prior to the transfer of the AAO membrane. The AAO membrane mask was fabricated by two-step anodization and subsequent removal of the aluminum support and the barrier layer, which was then transferred to the PMMA-coated Si substrate. Contact printing was performed on the sample with a pressure of 50 psi and a temperature of 120 °C to make a conformal contact of the AAO membrane mask to the Si substrate. The CF4 plasma etching was conducted to transfer nanopores onto the Si substrate through the PMMA interlayer. The introduced PMMA interlayer

  5. A tunable sub-100 nm silicon nanopore array with an AAO membrane mask: reducing unwanted surface etching by introducing a PMMA interlayer.

    Lim, Namsoo; Pak, Yusin; Kim, Jin Tae; Hwang, Youngkyu; Lee, Ryeri; Kumaresan, Yogeenth; Myoung, NoSoung; Ko, Heung Cho; Jung, Gun Young

    2015-08-28

    Highly ordered silicon (Si) nanopores with a tunable sub-100 nm diameter were fabricated by a CF4 plasma etching process using an anodic aluminum oxide (AAO) membrane as an etching mask. To enhance the conformal contact of the AAO membrane mask to the underlying Si substrate, poly(methyl methacrylate) (PMMA) was spin-coated on top of the Si substrate prior to the transfer of the AAO membrane. The AAO membrane mask was fabricated by two-step anodization and subsequent removal of the aluminum support and the barrier layer, which was then transferred to the PMMA-coated Si substrate. Contact printing was performed on the sample with a pressure of 50 psi and a temperature of 120 °C to make a conformal contact of the AAO membrane mask to the Si substrate. The CF4 plasma etching was conducted to transfer nanopores onto the Si substrate through the PMMA interlayer. The introduced PMMA interlayer prevented unwanted surface etching of the Si substrate by eliminating the etching ions and radicals bouncing at the gap between the mask and the substrate, resulting in a smooth Si nanopore array. PMID:26198752

  6. Manufacture and optimization of tubular ceramic membrane supports / Hertzog Bissett

    Bissett, Hertzog

    2005-01-01

    Inorganic membranes can be considered an alternative to organic membranes, due to their thermal, chemical and mechanical stability under harsh conditions. Ceramic membranes are used as support structures to increase permeability through composite inorganic membranes in separation processes. Tubular α-alumina membrane supports with smooth inner surfaces can be manufactured by means of the centrifugal casting technique. In this study, the effect of three different AKP powder size...

  7. Enhanced water vapour flow in silica microchannels and interdiffusive water vapour flow through anodic aluminium oxide (AAO) membranes

    Lei, Wenwen; McKenzie, David R.

    2015-12-01

    Enhanced liquid water flows through carbon nanotubes reinvigorated the study of moisture permeation through membranes and micro- and nano-channels. The study of water vapour through micro-and nano-channels has been neglected even though water vapour is as important as liquid water for industry, especially for encapsulation of electronic devices. Here we measure moisture flow rates in silica microchannels and interdiffusive water vapour flows in anodic aluminium oxide (AAO) membrane channels for the first time. We construct theory for the flow rates of the dominant modes of water transport through four previously defined standard configurations and benchmark it against our new measurements. The findings show that measurements of leak behaviour made using other molecules, such as helium, are not reliable. Single phase water vapour flow is overestimated by a helium measurement, while Washburn or capillary flow is underestimated or for all channels when boundary slip applies, to an extent that depends on the slip length for the liquid phase flows.

  8. Flux recovery of ceramic tubular membranes fouled with whey proteins: Some aspects of membrane cleaning

    Popović Svetlana S.; Milanović Spasenija D.; Iličić Mirela D.; Lukić Nataša Lj.; Šijački Ivana M.

    2008-01-01

    Efficiency of membrane processes is greatly affected by the flux reduction due to the deposits formation at the surface and/or in the pores of the membrane. Efficiency of membrane processes is affected by cleaning procedure applied to regenerate flux. In this work, flux recovery of ceramic tubular membranes with 50 and 200 nm pore size was investigated. The membranes were fouled with reconstituted whey solution for 1 hour. After that, the membranes were rinsed with clean water and then cleane...

  9. Resting microglial cells exhibit tubular membrane protrusions

    Ulrike Gimsa

    2002-11-01

    Full Text Available Nano- and microtubular structures have recently become a subject of increasing interest due to their importance in biology and medicine as well as their technological potential. Such structures have been observed in anorganic (Iijima, 1991 as well as in organic (Schnur 1993; Oda et al. 1991 systems. Micro- and nanotubular protrusions of bilayer membranes have been found in cells (Kralj-Iglic et al. 1998; Kralj-Iglic et al. 2001a and phospholipid vesicles (Kralj-Iglic et al. 2002; Kralj-Iglic et al. 2001b. In this work we describe membrane protrusions in microglial cells.

  10. Resting microglial cells exhibit tubular membrane protrusions

    Ulrike Gimsa; Veronika Kralj-Iglic; Jan Gimsa; Ales Iglic

    2002-01-01

    Nano- and microtubular structures have recently become a subject of increasing interest due to their importance in biology and medicine as well as their technological potential. Such structures have been observed in anorganic (Iijima, 1991) as well as in organic (Schnur 1993; Oda et al. 1991) systems. Micro- and nanotubular protrusions of bilayer membranes have been found in cells (Kralj-Iglic et al. 1998; Kralj-Iglic et al. 2001a) and phospholipid vesicles (Kralj-Iglic et al. 2002; Kralj-Igl...

  11. Experimental extrusion of tubular multilayer materials for Oxygen Transport Membranes

    Kothanda Ramachandran, Dhavanesan

    membrane based on gadolinia doped ceria oxide, (Ce0.9Gd0.1O1.95−δ), (CGO) was developed on a tubular, porous support structure based on cost-efficient magnesium oxide (MgO). The porous support structure was prepared by thermoplastic extrusion using MgO powder, thermoplastic binders and graphite pore former......, the permeation flux of the membrane improved significantly especially at low temperatures, reaching 4 Nml min-1 cm2 at 850 °C. The improved performance is attributed to an improvement of the catalytic activity of the Ni-CGO structure after a redox-cycle. Finally, oxygen permeation tests on the...... permeate side, most likely due to carbon formation....

  12. Flux recovery of ceramic tubular membranes fouled with whey proteins: Some aspects of membrane cleaning

    Popović Svetlana S.

    2008-01-01

    Full Text Available Efficiency of membrane processes is greatly affected by the flux reduction due to the deposits formation at the surface and/or in the pores of the membrane. Efficiency of membrane processes is affected by cleaning procedure applied to regenerate flux. In this work, flux recovery of ceramic tubular membranes with 50 and 200 nm pore size was investigated. The membranes were fouled with reconstituted whey solution for 1 hour. After that, the membranes were rinsed with clean water and then cleaned with sodium hydroxide solutions or formulated detergents (combination of P3 Ultrasil 67 and P3 Ultrasil 69. Flux recovery after the rinsing step was not satisfactory although fouling resistance reduction was significant so that chemical cleaning was necessary. In the case of 50 nm membrane total flux recovery was achieved after cleaning with 1.0% (w/w sodium hydroxide solution. In the case of 200 nm membrane total flux recovery was not achieved irrespective of the cleaning agent choice and concentration. Cleaning with commercial detergent was less efficient than cleaning with the sodium hydroxide solution.

  13. Experimental Investigation of Heat and Mass Transfer in Tubular Membrane Distillation Module for Desalination

    Adnan Al-Hathal Al-Anezi; Sharif, Adel O.; Sanduk, M. I.; Khan, A. R.

    2012-01-01

    Membrane distillation is a thermally driven membrane process for seawater desalination and purification at moderate temperatures and pressures. A hydrophobic micro-porous membrane is used in this process, which separates hot and cold water, allowing water vapor to pass through; while restricting the movement of liquid water, due to its hydrophobic nature. This paper provides an experimental investigation of heat and mass transfer in tubular membrane module for water desalination. Different op...

  14. 超薄 AAO 模板法辅助生长高密度有序金纳米点阵列%Fabrication of High-Density and Ordered Au Nanodot Arrays by Ultra-Thin Anodic Aluminum Oxide (AAO) Membranes

    杨震; 张璋; 黄康荣; 周青伟; 刘利伟

    2013-01-01

    在高真空状态下采用孔径为40 nm的超薄阳极氧化铝( AAO)模板作为掩膜进行金的热蒸镀,制备了平均粒径为35.5 nm、填充密度为1.45×1010 cm-2的金纳米点阵列.探索了高密度有序纳米点阵列的制备工艺.通过扫描电子显微镜(SEM)和原子力显微镜(AFM)对金纳米点阵列进行表面形貌表征,证明超薄AAO模板法明显改善了金纳米点阵列分布的尺寸均匀度和有序度.%High-density Au nanodot arrays have attracted a lot of interests because of their potential applications in catalyst and biosensor .This article focused on the research of the manufacture of high-density and well-ordered Au nanodot arrays with size of 40 nm ultra-thin Anodic Aluminum Oxide ( AAO) membrane ( the result of our experi-mental exploration ) being the mask .Well-ordered Au nanodot arrays have fabricated by high-vacuum Au thermal e-vaporation with the help of AAO masks bonded on the desired substrates .The diameters of Au nanodots have been highly controlled with 35.5 nm, the packing-density could achieve to as high as 1.45 ×1010 cm-2 .The morphology of the Au nanodot arrays has been investigated by the SEM and AFM .The SEM images confirmed that the uniformi-ty of the size distribution and structural ordering of Au nanodot arrays had been improved by the two -step anodiza-tion of AAO.

  15. Copper recovery in a bench-scale carrier facilitated tubular supported liquid membrane system

    Makaka S.

    2010-01-01

    Full Text Available The extraction of copper ions in a tubular supported liquid membrane using LIX 984NC as a mobile carrier was studied, evaluating the effect of the feed characteristics (flowrate, density, viscosity on the feedside laminar layer of the membrane. A vertical countercurrent, double pipe perspex benchscale reactor consisting of a single hydrophobic PVDF tubular membrane mounted inside was used in all test work. The membrane was impregnated with LIX 984NC and became the support for this organic transport medium. Dilute Copper solution passed through the centre pipe and sulphuric acid as strippant passed through the shell side. Copper was successfully transported from the feedside to the stripside and from the data obtained, a relationship between Schmidt, Reynolds and Sherwood number was achieved of.

  16. PROCESSING AND CHARACTERIZATION OF TUBULAR CERAMIC SUPPORT FOR MICROFILTRATION MEMBRANE PREPARED FROM PYROPHYLLITE CLAY

    Abedallah Talidi

    2011-09-01

    Full Text Available Tubular macroporous support for ceramic microfiltration membranes were prepared by extrusion followed by sintering of the low cost pyrophyllite clay. Clay powders mixed with some organic additives can be extruded to form a porous tubular support. The average pore size of the membrane is observed to increase from 5 µm to 10.8 µm when sintering temperature increase from 900 °C to 1200 °C. However, with the increase in temperature from 900 °C to 1200 °C, the support porosity is reduced from 47% to 30% and flexural strength is increased from 4 MPa to 17 MPa. The fabricated macro-porous supports are expected to have potential applications in the pre-treatment and also can be used like support for membranes of ultra-filtration.

  17. Direct synthesis of a titania membrane on a centrifugally casted tubular ceramic support

    Patterson, V.A.; Krieg, H.M.; Kriek, R.J.; Bisset, H.

    2006-01-01

    In-house manufactured tubular ceramic supports prepared by centrifugal casting have a smooth inside surface and are ideal for thin defect-free coatings. The aim of this study was to directly coat a thin defect-free titania membrane in the anatase crystal structure on a ceramic support. The membrane preparation was successful. By means of XRD it was confirmed that the continuous and defect-free titania top-layer (thickness = 1.5–1.6 μm) was in the anatase crystal structure. According to the ga...

  18. Preparation of electrolyte membranes for micro tubular solid oxide fuel cells

    2008-01-01

    Yttria-stabilized zirconia (YSZ) micro tubular electrolyte membranes for solid oxide fuel cells (SOFCs) were prepared via the combined wet phase inversion and sintering technique. The as-derived YSZ mi- cro tubes consist of a thin dense skin layer and a thick porous layer that can serve as the electrode of fuel cells. The dense and the porous electrolyte layers have the thickness of 3-5 μm and 70-90 μm, respectively, while the inner surface porosity of the porous layer is higher than 28.1%. The two layers are perfectly integrated together to preclude the crack or flake of electrolyte film from the electrode. The presented method possesses distinct advantages such as technological simplicity, low cost and high reliability, and thus provides a new route for the preparation of micro tubular SOFCs.

  19. Functional reconstitution of rhodopsin into tubular lipid bilayers supported by nanoporous media.

    Soubias, Olivier; Polozov, Ivan V; Teague, Walter E; Yeliseev, Alexei A; Gawrisch, Klaus

    2006-12-26

    We report on a novel reconstitution method for G-protein-coupled receptors (GPCRs) that yields detergent-free, single, tubular membranes in porous anodic aluminum oxide (AAO) filters at concentrations sufficient for structural studies by solid-state NMR. The tubular membranes line the inner surface of pores that traverse the filters, permitting easy removal of detergents during sample preparation as well as delivery of ligands for functional studies. Reconstitution of bovine rhodopsin into AAO filters did not interfere with rhodopsin function. Photoactivation of rhodopsin in AAO pores, monitored by UV-vis spectrophotometry, was indistinguishable from rhodopsin in unsupported unilamellar liposomes. The rhodopsin in AAO pores is G-protein binding competent as shown by a [35S]GTPgammaS binding assay. The lipid-rhodopsin interaction was investigated by 2H NMR on sn-1- or sn-2-chain perdeuterated 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phospholine as a matrix lipid. Rhodopsin incorporation increased mosaic spread of bilayer orientations and contributed to spectral density of motions with correlation times in the range of nano- to microseconds, detected as a significant reduction in spin-spin relaxation times. The change in lipid chain order parameters due to interaction with rhodopsin was insignificant. PMID:17176079

  20. Growth hormone activates phospholipase C in proximal tubular basolateral membranes from canine kidney

    To delineate pathways for signal transduction by growth hormone (GH) in proximal tubule, the authors incubated basolateral membranes isolated from canine kidney with human growth hormone (hGH) or human prolactin (hPrl) and measured levels of inositol trisphosphate (InsP3) in suspensions and of diacylglycerol extractable from the membranes. Incubation with hGH, but not hPrl, increased levels of InsP3 and diacylglycerol in a concentration-dependent manner. Half-maximal effects occurred between 0.1 and 1 nM hGH. Increased levels of InsP3 were measured after as little as 5 sec of incubation with 1 nM hGH, and increase was maximal after 15 sec. Increases were no longer detectable after 60 sec because of dephosphorylation of InsP3 in membrane suspensions. hGH did not affect rates of dephosphorylation. hGH-stimulated increases in InsP3 were detectable in membranes suspended in 0, 0.1, and 0.2 μM calcium but not in 0.3 or 1.0 μM calcium. 125I-labeled hGH-receptor complexes with Mr values of 66,000 and 140,000 were identified in isolated basolateral membranes. The findings establish that GH activates phospholipase C in isolated canine renal proximal tubular basolateral membranes, potentially after binding to a specific receptor. This process could mediate signal transmission by GH across the plasma membrane of the proximal tubular cell and elsewhere

  1. Quantificational Etching of AAO Template

    Guojun SONG; Dong CHEN; Zhi PENG; Xilin SHE; Jianjiang LI; Ping HAN

    2007-01-01

    Ni nanowires were prepared by electrodeposition in porous anodized aluminum oxide (AAO) template from a composite electrolyte solution. Well-ordered Ni nanowire arrays with controllable length were then made by the partial removal of AAO using a mixture of phosphoric acid and chromic acid (6 wt pct H3PO4:1.8 wt pct H3CrO4). The images of Ni nanowire arrays were studied by scanning electron microscopy (SEM) to determine the relationship between etching time and the length of Ni nanowire arrays. The results indicate that the length of nanowires exposed from the template can be accurately controlled by controlling etching time.

  2. Fracture modes in tubular LSFCO ceramic membranes under graded reducing conditions

    Highlights: ► Microstructural evolution in LSFCO membranes under graded environment is reported. ► The role of chemically induced stresses and oxygen deficiency is evaluated. ► The stress distribution is modeled by a point defect model. - Abstract: Chromium (III) oxide (Cr2O3)-doped LaSrFeO3 perovskite, La0.2Sr0.8Fe0.8Cr0.2O3−δ (LSFCO), is being considered as a potential material for applications in solid oxide fuel cells, gas separation membranes, and electrochemical reactors because of its high electro-catalytic activity. Similar to other perovskites, the performance and mechanical strength of LSFCO materials are significantly affected by environment and temperature. Here, we report a fracture gradient phenomenon in tubular C-ring-shaped LSFCO ceramic membranes under graded reducing conditions. The graded reducing condition was produced by flushing N2 on the outer side of the C-ring membranes at 1000 °C while keeping the inner side untreated. The rings were then diametrically compressed to fracture, and the resultant fracture morphology was analyzed with a scanning electron microscope (SEM). A fracture gradient with three distinct regions across the thickness of the membranes was identified on the split surfaces. In the outer region of the C-ring specimen exposed to N2, a mixed inter/transgranular fracture with a predominant intergranular pattern was observed. In the middle section of the fracture surface, a characteristic transgranular fracture of the perovskite grains was found. At the inner region of the ring, a mixed inter/transgranular fracture with a predominant transgranular pattern occurred. The mechanism of gradient fractures was attributed both to chemically induced stresses caused by oxygen diffusion and to the formation of a separate phase of oxygen-deficient perovskite in the parent perovskite. The stresses generated were modeled by a point defect model. This work provides significant information on microstructure evolutions of tubular

  3. Tubular lipid membranes pulled from vesicles: Dependence of system equilibrium on lipid bilayer curvature

    Golushko, I. Yu.; Rochal, S. B.

    2016-01-01

    Conditions of joint equilibrium and stability are derived for a spherical lipid vesicle and a tubular lipid membrane (TLM) pulled from this vesicle. The obtained equations establish relationships between the geometric and physical characteristics of the system and the external parameters, which have been found to be controllable in recent experiments. In particular, the proposed theory shows that, in addition to the pressure difference between internal and external regions of the system, the variable spontaneous average curvature of the lipid bilayer (forming the TLM) also influences the stability of the lipid tube. The conditions for stability of the cylindrical phase of TLMs after switching off the external force that initially formed the TLM from a vesicle are discussed. The loss of system stability under the action of a small axial force compressing the TLM is considered.

  4. Application of high speed imaging as a novel tool to study particle dynamics in tubular membrane systems

    Lindeboom, R.E.F.; Smith, G.; Jeison, D.A.; Temmink, B.G.; Lier, van, Pol

    2011-01-01

    Membrane bioreactors represent a promising technology for wastewater treatment, already applied to a wide variety of industrial effluents and sewage. Gas or air sparging is a commonly applied approach to generate surface shear to control fouling phenomena and cake formation causing flux reduction. In inside-out tubular membranes, gas sparging is usually applied to promote the development of a slug flow regime. Our present paper describes the development of a novel technique to study particle ...

  5. Fabrication and performance of a tubular ceria based oxygen transport membrane on a low cost MgO support

    Kothanda Ramachandran, Dhavanesan; Søgaard, Martin; Clemens, F.;

    2015-01-01

    A 30 μm thin-film tubular CGO (Ce0.9Gd0.1O1.95−δ) membrane with catalytic layers on both sides has been prepared by dip-coating on a low cost, porous magnesium oxide (MgO) support. The MgO support was fabricated through a thermoplastic extrusion process. Support, thin membrane and catalytic layers...

  6. Assessment of Mass Transfer Coefficients in Coalescing Slug Flow in Vertical Pipes and Applications to Tubular Airlift Membrane Bioreactors

    Ratkovich, Nicolas Rios; Berube, P.R.; Nopens, I.

    2011-01-01

    One of the operational challenges associated with membrane bioreactors (MBRs) is the fouling of the membranes. In tubular side-stream MBRs, fouling reduction can be achieved through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. The two-phase slug flow induces......) cannot be applied directly. As an alternative, in this work, a multidisciplinary approach was selected, by exploiting dimensionless analysis using the Sherwood number. Mass transfer coefficients were measured at various superficial velocities of gas and liquid flow in a tubular system. Due to the...... variability of the mass transfer coefficient obtained for each experimental condition, the results were compiled into, mass transfer coefficient histograms (MTH) for analysis. A bimodal MTH was observed, with one peak corresponding to the mass transfer induced by the liquid flow, and the other peak induced by...

  7. Mathematical modelling of flux recovery during chemical cleaning of tubular membrane fouled with whey proteins

    Marković Jelena Đ.

    2009-01-01

    Full Text Available Membrane process efficiency in the dairy industry is impaired by the formation of deposits during filtration processes. This work describes cleaning procedures for ceramic tubular membrane (50 nm fouled with whey proteins. Also, mathematical modelling was performed to obtain models which allow deeper insight into the mechanisms involved during cleaning procedures. The caustic solutions (0.2%w/w, 0.4%w/w and 1.0%w/w NaOH and the mixture of two commercial detergents (0.8%w/w P3-ultrasil 69+0.5% w/w P3-ultrasil 67 and 1.2% P3-ultrasil 69+0.75 P3-ultrasil 67 were used as chemical cleaning agents. The results showed that the best flux recovery was achieved with 0.4%w/w NaOH solution. After analyzing the experimental data, five parameter and six parameter kinetic models were suggested for alkali and detergent cleaning, respectively. The changes of total and specific resistances, as well as the change of the effective pore diameter and deposit thickness during cleaning are estimated by applying these models.

  8. AAO Observer - February 2011 Edition

    Brough, Sarah

    2011-01-01

    This edition of the Australian Astronomical Observatory Observer contains articles on the detection of the baryonic acoustic oscillation signal over a wide range of redshifts by the WiggleZ dark energy survey; results and future plans for the Galaxy And Mass Assembly survey; an update on the HERMES instrument; a report on the use of the AAT as a testbed for experiments using a laser frequency comb to achieve ultra-precise calibration of spectrographs; an innovative project combining professional astronomers and highly professional 'amateurs' to discover and characterise planets orbiting binary stars and finding out what it's like to be present when the comet you discovered encounters a spacecraft! The AAO's Distinguished Visitors for 2011 are introduced and an announcement is made for the upcoming Southern Cross Conference on 'Supernovae and their Host Galaxies' to be held in Sydney in June 2011.

  9. Efektivitas Membran Amnion Liofilisasi (Handmade Tubular sebagai Nerve Conduit pada Perbaikan Cedera Saraf Perifer Tikus dengan Gap 5 mm

    R. Dadan G. Gandadikusumah

    2013-09-01

    Full Text Available Peripheral nerve injury with 5–30 mm gap which is caused by direct injury cases (87% or iatrogenic (12% become a special concern because it could cause a serious disability in the future. Therefore, we need many kinds of nerve repair methods without adding morbidity to the patient. One of the methods is entubulation method, by using natural or synthetic material. This was an animal experimental research by using simple random design in Departement Pharmachology Laboratory, Faculty of Medicine, Universitas Padjadjaran Bandung in May 2012. The samples were used 14 Wistar rats, divided into 2 groups. After creating gap on sciatic nerve, nerve conduit was installed on case group by using handmade tubular lyophilized amnion membrane. Nerve conduit was not installed in control group. After 21 days observation, conduction test and histopathology examination were done. Data were analyzed by using non-parametric statistical analysis sign test. All animals survived without any serious surgical complication. Result showed a significant difference between groups; the conduction test=0.016 (p<0.05, nerve growth to distal gap=0.063 (p<0.05, no radier direction of nerve growth=0.031 (p<0.05. Reaction of inflammation was minimum and there was no difference between two groups. In conclusion, handmade tubular lyophilized amnion membrane is effective as nerve conduit in repair of peripheral nerve injury with 5 mm gap.

  10. A colorimetric sensor based on anodized aluminum oxide (AAO) substrate for the detection of nitroaromatics.

    Liu, Y.; Wang, H. H.; Indacochea, J. E.; Wang, M. L. (Materials Science Division); (Northeastern Univ.); (Univ. of Illinois at Chicago)

    2011-12-15

    Simple and low cost colorimetric sensors for explosives detection were explored and developed. Anodized aluminum oxide (AAO) with large surface area through its porous structure and light background color was utilized as the substrate for colorimetric sensors. Fabricated thin AAO films with thickness less than {approx} 500 nm allowed us to observe interference colors which were used as the background color for colorimetric detection. AAO thin films with various thickness and pore-to-pore distance were prepared through anodizing aluminum foils at different voltages and times in dilute sulfuric acid. Various interference colors were observed on these samples due to their difference in structures. Accordingly, suitable anodization conditions that produce AAO samples with desired light background colors for optical applications were obtained. Thin film interference model was applied to analyze the UV-vis reflectance spectra and to estimate the thickness of the AAO membranes. We found that the thickness of produced AAO films increased linearly with anodization time in sulfuric acid. In addition, the growth rate was higher for AAO anodized using higher voltages. The thin film interference formulism was further validated with a well established layer by layer deposition technique. Coating poly(styrene sulfonate) sodium salt (PSS) and poly(allylamine hydrochloride) (PAH) layer by layer on AAO thin film consistently shifted its surface color toward red due to the increase in thickness. The red shift of UV-vis reflectance was correlated quantitatively to the number of layers been assembled. This sensitive red shift due to molecular attachment (increase in thickness) on AAO substrate was applied toward nitroaromatics detection. Aminopropyltrimethoxysilane (APTS) which can be attached onto AAO nanowells covalently through silanization and attract TNT molecules was coated and applied for TNT detection. UV-vis spectra of AAO with APTS shifted to the longer wavelength side due to

  11. The heterostructured AAO/CeO2 nanosystem fabricated by electrodeposition for charge storage and hydrophobicity

    Highlights: • Tilted cathode was adopted to fabricate PAAM during the second anodization. • AAO/CeO2 nanosystem was prepared from PAAM by electrochemical deposition. • The larger the cathode intersection angle, the more the charges are stored in the system. • The system's hydrophobicity was improved by an increase in tilted cathode angle. • The optimum angle of the tilted cathode is 40° for charge storage and hydrophobicity. -- Abstract: Tilted cathode was adopted to prepare porous anodic alumina membrane (PAAM) during the second aluminum anodic oxidation (AAO). A heterostructured AAO/CeO2 nanosystem was fabricated by filling CeO2 into the PAAM by electrochemical deposition. The larger the intersection angle of the cathode, the more the charge storage of the fabricated system. A lower potential scan rate is beneficial to the electrochemical charge storage of the system. With the cathode intersection angle increasing, the hydrophobicity of the AAO/CeO2 system is greatly improved. As the 40° is the optimum angle, the charge storage and hydrophobicity of the system increase with the increasing cathode intersection angle up to 40°. The AAO/CeO2 system could be utilized in both charge storage and self-cleaning

  12. Stress analysis and fail-safe design of bilayered tubular supported ceramic membranes

    Kwok, Kawai; Frandsen, Henrik Lund; Søgaard, Martin; Hendriksen, Peter Vang

    2014-01-01

    Supported ceramic membranes based on mixed ionic and electronic conductors are a promising technology for oxygen separation applications. In addition to chemically induced stress under oxygen activity gradients in the materials, strain mismatch between membrane and support gives rise to considera......Supported ceramic membranes based on mixed ionic and electronic conductors are a promising technology for oxygen separation applications. In addition to chemically induced stress under oxygen activity gradients in the materials, strain mismatch between membrane and support gives rise to....... Stress distributions in two membrane systems have been analyzed and routes to minimize stress are proposed. For a Ba0.5Sr0.5Co0.8Fe0.2O3−δBa0.5Sr0.5Co0.8Fe0.2O3−δ membrane supported on a porous substrate of the same material under pressure-vacuum operation, the optimal configuration in terms of...

  13. ARSENIC DETERMINATION IN SALINE WATERS UTILIZING A TUBULAR MEMBRANE AS A GAS-LIQUID SEPATRATOR FOR HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    A tubular silicone rubber membrane is evaluated as a gas-liquid separator for the determination of arsenic in saline waters via HG-ICP-MS. The system was optimized in terms of NaBH and HCI concentrations. The intermediate gas and carrier gas were optimized in terms of sensitiity ...

  14. Heat-And-Mass Transfer Relationship to Determine Shear Stress in Tubular Membrane Systems

    Ratkovich, Nicolas Rios; Nopens, Ingmar

    2012-01-01

    The main drawback of Membrane Bioreactors (MBRs) is the fouling of the membrane. One way to reduce this fouling is through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. It has been proven in literature that the slug flow pattern has a higher scouring effect to remove particulates due to the high shear rates and high mass transfer between the membrane surface and the bulk region. However, to calculate the mass transfer coefficient in an efficient and accur...

  15. Evaluation of a new on-stream supercritical fluid deposition process for sol-gel preparation of silica-based membranes on tubular supports

    A novel 'On-Stream Supercritical Fluid Deposition' (OS-SFD) process has been investigated in this work coupling the sol-gel chemistry and a filtration/compression operation in supercritical CO2 (sc-CO2), for the production of uniform membranes on/in porous ceramic tubular supports. The versatility of this process allows both the direct formation of thin coatings on porous tubular membrane supports but also their internal modification. An attractive on-line control of the deposition process was operated by recording the transmembrane pressure evolution during membrane formation. Silica membranes were directly deposited on macroporous supports (155 mm long -Al2O3, with 200 nm pore sizes) from TEOS derived sols dissolved in sc-CO2 and transported to the tubular support where the condensation/gelation and deposition occurred. The deposition mechanism has been correlated with the sol-gel transition in sc-CO2 conditions and the impact of the deposition temperature, sol formulation and sc-CO2 flow rate on the membrane characteristics (morphology, weight increase and single gas permeance) have been discussed. Supersaturation and precipitation of transported clusters followed by their condensation and gelation were found as key parameters controlling the silica-based membrane design and microstructure/compacity of the silica network. (authors)

  16. Three-Dimensional Visualization of the Tubular-Lamellar Transformation of the Internal Plastid Membrane Network during Runner Bean Chloroplast Biogenesis.

    Kowalewska, Łucja; Mazur, Radosław; Suski, Szymon; Garstka, Maciej; Mostowska, Agnieszka

    2016-04-01

    Chloroplast biogenesis is a complex process that is integrated with plant development, leading to fully differentiated and functionally mature plastids. In this work, we used electron tomography and confocal microscopy to reconstruct the process of structural membrane transformation during the etioplast-to-chloroplast transition in runner bean (Phaseolus coccineus). During chloroplast development, the regular tubular network of paracrystalline prolamellar bodies (PLBs) and the flattened porous membranes of prothylakoids develop into the chloroplast thylakoids. Three-dimensional reconstruction is required to provide us with a more complete understanding of this transformation. We provide spatial models of the bean chloroplast biogenesis that allow such reconstruction of the internal membranes of the developing chloroplast and visualize the transformation from the tubular arrangement to the linear system of parallel lamellae. We prove that the tubular structure of the PLB transforms directly to flat slats, without dispersion to vesicles. We demonstrate that the grana/stroma thylakoid connections have a helical character starting from the early stages of appressed membrane formation. Moreover, we point out the importance of particular chlorophyll-protein complex components in the membrane stacking during the biogenesis. The main stages of chloroplast internal membrane biogenesis are presented in a movie that shows the time development of the chloroplast biogenesis as a dynamic model of this process. PMID:27002023

  17. Effects of heat treatment on optical absorption properties of Ni-P/AAO nano-array composite structure

    Liu, Yi-Fan; Wang, Feng-Hua; Guo, Dong-Lai; Huang, Sheng-You; Zou, Xian-Wu [Wuhan University, Department of Physics, Wuhan (China); Sang, Jian-Ping [Wuhan University, Department of Physics, Wuhan (China); Jianghan University, Department of Physics, Wuhan (China)

    2009-11-15

    Ni-P/AAO nano-array composite structure assemblies with Ni and P grown in the pores of anodic aluminum oxide (AAO) membranes were prepared by electroless deposition. The results of SEM, TEM and SAED show that as-deposited Ni-P nanowires have an amorphous structure and a few nanocrystallites form after annealing. The optical absorption spectra reveal that, as the annealing temperature increases, the absorption band edge of the Ni-P/AAO composite structure is obviously blue shifted, which is attributed to a decrease of the internal pressure after heat treatment. Meanwhile, the annealed Ni-P/AAO nano-array composite structure exhibits the absorption behavior of a direct band gap semiconductor. Details of this behavior are discussed together with the implications for potential device applications. (orig.)

  18. Heat-And-Mass Transfer Relationship to Determine Shear Stress in Tubular Membrane Systems

    Ratkovich, Nicolas Rios; Nopens, Ingmar

    2012-01-01

    The main drawback of Membrane Bioreactors (MBRs) is the fouling of the membrane. One way to reduce this fouling is through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. It has been proven in literature that the slug flow pattern has a higher scouring effect to...... measurements are required. Therefore, this work proposes an alternative method that uses already existing heat transfer relationships for two phase flow and links them through a dimensionless number to the mass transfer coefficient (Sherwood number) to obtain an empirical relationship which can be used to...

  19. ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice

    Jones, Frances E.; Bailey, Matthew A.; Murray, Lydia S.; Lu, Yinhui; McNeilly, Sarah; Schlötzer-Schrehardt, Ursula; Lennon, Rachel; Sado, Yoshikazu; Brownstein, David G.; Mullins, John J.; Kadler, Karl E.; Van Agtmael, Tom

    2016-01-01

    ABSTRACT Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies. PMID:26839400

  20. Analysis of Shear Stress and Energy Consumption in a Tubular Airlift Membrane System

    Ratkovich, Nicolas Rios; Chan, C.C.V.; Berube, P.R.;

    2011-01-01

    Application of a two-phase slug flow in side-stream membrane bioreactors (MBRs) has proven to increase the permeate flux and decrease fouling through a better control of the cake layer. Past literature has shown that the hydrodynamics near the membrane surface have an impact on the degree of foul...... that optimize fouling control. Furthermore, the total energy consumption of the system was estimated based on the two-phase pressure drop. It was found that low liquid and high gas flow rates (ratio of approx. 4) balanced the peaks and minimized the energy consumption....

  1. Experimental and theoretical analysis of tubular membrane aeration for Mammalian cell bioreactors.

    Qi, Hanshi N; Goudar, Chetan T; Michaels, James D; Henzler, Hans-Jugen; Jovanovic, Goran N; Konstantinov, Konstantin B

    2003-01-01

    A combination of experimental and theoretical approaches was used to characterize the dynamics of oxygen transfer in a membrane-aerated bioreactor. Pressure profiles along the length of the membrane at varying entrance and exit pressures were determined by actual experimental measurements, unlike most previous studies that have relied solely on theoretical descriptions of the pressure profile in the tubing. The mass transfer coefficient, k(L)a, was also determined under these conditions and was found to be essentially independent of tubing exit pressure. Measurement of the tubing pressure profile coupled with estimation of k(L)a allowed for computation of the oxygen transfer rate (OTR) along the length of the tubing. A mathematical model that incorporated friction pressure loss and losses due to tubing bending was developed to describe the pressure and hence OTR characteristics of membrane-aerated systems. The applicability of the model was verified by testing it on experimentally measured pressure data, and in all cases the model accurately described experimental data. When tubing properties are known, the mathematical model presented in this study allows for a priori estimation of OTR profiles along the length of the tubing. This information is vital for optimal design and scale-up of membrane-aerated bioreactors for mammalian cell culture. PMID:12892480

  2. FBAR syndapin 1 recognizes and stabilizes highly curved tubular membranes in a concentration dependent manner

    Ramesh, Pradeep; Baroji, Younes F.; Seyyed Reihani, Seyyed Nader;

    2013-01-01

    Syndapin 1 FBAR, a member of the Bin-amphiphysin-Rvs (BAR) domain protein family, is known to induce membrane curvature and is an essential component in biological processes like endocytosis and formation and growth of neurites. We quantify the curvature sensing of FBAR on reconstituted porcine...

  3. A Cluster of Thin Tubular Structures Mediates Transformation of the Endoplasmic Reticulum to Autophagic Isolation Membrane

    Uemura, Takefumi; Yamamoto, Masaya; Kametaka, Ai; Sou, Yu-shin; Yabashi, Atsuko; Yamada, Akane; Annoh, Hiromichi; Kametaka, Satoshi; Komatsu, Masaaki; Waguri, Satoshi

    2014-01-01

    Recent findings have suggested that the autophagic isolation membrane (IM) might originate from a domain of the endoplasmic reticulum (ER) called the omegasome. However, the morphological relationships between ER, omegasome, and IM remain unclear. In the present study, we found that hybrid structures composed of a double FYVE domain-containing protein 1 (DFCP1)-positive omegasome and the IM accumulated in Atg3-deficient mouse embryonic fibroblasts (MEFs). Moreover, correlative light and elect...

  4. Rejection of organic micro-pollutants from water by a tubular, hydrophilic pervaporative membrane designed for irrigation applications.

    Sule, May N; Templeton, Michael R; Bond, Tom

    2016-01-01

    The links between chemical properties, including those relating to molecular size, solubility, hydrophobicity and vapour pressure, and rejection of model aromatic micro-pollutants by a tubular, hydrophilic polymer pervaporation membrane designed for irrigation applications were investigated. Open air experiments were conducted at room temperature for individual solutions of fluorene, naphthalene, phenol, 1,2-dichlorobenzene, 1,2-diethylbenzene and 2-phenoxyethanol. Percentage rejection generally increased with increased molecular size for the model micro-pollutants (47-86%). Molecular weight and log Kow had the strongest positive relationships with rejection, as demonstrated by respective correlation coefficients of r = 0.898 and 0.824. Rejection was also strongly negatively correlated with aqueous solubility and H-bond δ. However, properties which relate to vapour phase concentrations of the micro-pollutants were not well correlated with rejection. Thus, physicochemical separation processes, rather than vapour pressure, drive removal of aromatic contaminants by the investigated pervaporation tube. This expanded knowledge could be utilized in considering practical applications of pervaporative irrigation systems for treating organic-contaminated waters such as oilfield-produced waters. PMID:26585567

  5. The Na conductance in the sarcolemma and the transverse tubular system membranes of mammalian skeletal muscle fibers.

    DiFranco, Marino; Vergara, Julio L

    2011-10-01

    Na (and Li) currents and fluorescence transients were recorded simultaneously under voltage-clamp conditions from mouse flexor digitorum brevis fibers stained with the potentiometric dye di-8-ANEPPS to investigate the distribution of Na channels between the surface and transverse tubular system (TTS) membranes. In fibers rendered electrically passive, voltage pulses resulted in step-like fluorescence changes that were used to calibrate the dye response. The effects of Na channel activation on the TTS voltage were investigated using Li, instead of Na, because di-8-ANEPPS transients show anomalies in the presence of the latter. Na and Li inward currents (I(Na), I(Li); using half of the physiological ion concentration) showed very steep voltage dependences, with no reversal for depolarizations beyond the calculated equilibrium potential, suggesting that most of the current originates from a noncontrolled membrane compartment. Maximum peak I(Li) was ∼ 30% smaller than for I(Na), suggesting a Li-blocking effect. I(Li) activation resulted in the appearance of overshoots in otherwise step-like di-8-ANEPPS transients. Overshoots had comparable durations and voltage dependence as those of I(Li). Simultaneously measured maximal overshoot and peak I(Li) were 54 ± 5% and 773 ± 53 µA/cm(2), respectively. Radial cable model simulations predicted the properties of I(Li) and di-8-ANEPPS transients when TTS access resistances of 10-20 Ω cm(2), and TTS-to-surface Na permeability density ratios in the range of 40:60 to 70:30, were used. Formamide-based osmotic shock resulted in incomplete detubulation. However, results from a subpopulation of treated fibers (low capacitance) provide confirmatory evidence that a significant proportion of I(Li), and the overshoot in the optical signals, arises from the TTS in normal fibers. The quantitative evaluation of the distribution of Na channels between the sarcolemma and the TTS membranes, as provided here, is crucial for the

  6. Flow injection analysis with tubular membrane ion-selective electrode and coated wires for buspirone hydrochloride.

    Abdel-Ghani, Nour; Issa, Yousry; Shoukry, Adel; Ahmed, Howayda

    2007-01-01

    New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tetraphenylborate was prepared. The electrode exhibited mean slope of calibration graph of 58.4 mV per decade of BusCl concentration at 25 degrees C. The electrode can be used within the concentration range 6.3 x 10(-5) - 10(-2) M BusCl at a pH range of 2.5-7.0. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode, amounting to 0.00056 V degrees C(-1). The electrode showed a very good selectivity for BusCl with respect to a number of inorganic cations, sugars and amino acids. The electrode was applied to the potentiometric determination of the buspirone ion and its pharmaceutical preparation under batch and flow injection conditions. Also, buspirone was determined by conductimetric titrations. Graphite rod, copper and silver coated wire electrodes were prepared and characterized as sensors for the drug under investigation. PMID:17822267

  7. Micellar nanotubes and AAO nanopores decorated with nanoparticles

    We demonstrated that anodized aluminum oxide (AAO) enables the fabrication of micellar nanotubes and nanopores decorated with nanoparticles. Block copolymer micelles containing precursors of nanoparticles were coated on the nanopores of AAO, from which we were able to select nanotubes containing nanoparticles or nanopores decorated with nanoparticles by removing the AAO template or the copolymer. Upon removal of the AAO, the micellar nanotubes with nanoparticles were produced, whereas the nanopores of AAO were decorated with nanoparticles by eliminating the copolymer. Since a variety of nanoparticles can be synthesized in addition to full control over the size and spacing of nanoparticles by the copolymer micellar approach, the methodology demonstrated here can allow fabricating functional nanotubes or nanopores with a selection of the type and size of nanoparticles.

  8. A Rare Case of Type I RenalTubular Acidosis with Membranous Nephropathy Presenting as Hypokalemic Paralysis

    Sunder, Sham; Sathi, Satyanand; K Venkataramanan; Verma, Himanshu; Bhardwaj, Minakshi; Rajesh, J.; Mahapatra, Himanshu

    2013-01-01

    Type 1 renal tubular acidosis (RTA), or distal RTA (dRTA), is a disorder of renal tubular acidification, which is generally asymptomatic but may rarely present as hypokalemic paralysis. Here, we report the case of a young male who presented with sudden onset weakness of all 4 limbs and a 2-month history of swelling of the legs. An investigation revealed hypokalemia, metabolic acidosis, and nephrotic syndrome. Additional analyses revealed normal anion gap metabolic acidosis with a positive uri...

  9. Surface heat shock protein 90 serves as a potential receptor for calcium oxalate crystal on apical membrane of renal tubular epithelial cells.

    Fong-Ngern, Kedsarin; Sueksakit, Kanyarat; Thongboonkerd, Visith

    2016-07-01

    Adhesion of calcium oxalate monohydrate (COM) crystals on renal tubular epithelial cells is a crucial step in kidney stone formation. Finding potential crystal receptors on the apical membrane of the cells may lead to a novel approach to prevent kidney stone disease. Our previous study identified a large number of crystal-binding proteins on the apical membrane of MDCK cells. However, their functional role as potential crystal receptors had not been validated. The present study aimed to address the potential role of heat shock protein 90 (HSP90) as a COM crystal receptor. The apical membrane was isolated from polarized MDCK cells by the peeling method and recovered proteins were incubated with COM crystals. Western blot analysis confirmed the presence of HSP90 in the apical membrane and the crystal-bound fraction. Immunofluorescence staining without permeabilization and laser-scanning confocal microscopy confirmed the surface HSP90 expression on the apical membrane of the intact cells. Crystal adhesion assay showed that blocking surface HSP90 by specific anti-HSP90 antibody and knockdown of HSP90 by small interfering RNA (siRNA) dramatically reduced crystal binding on the apical surface of MDCK cells (by approximately 1/2 and 2/3, respectively). Additionally, crystal internalization assay revealed the presence of HSP90 on the membrane of endocytic vesicle containing the internalized COM crystal. Moreover, pretreatment of MDCK cells with anti-HSP90 antibody significantly reduced crystal internalization (by approximately 1/3). Taken together, our data indicate that HSP90 serves as a potential receptor for COM crystals on the apical membrane of renal tubular epithelial cells and is involved in endocytosis/internalization of the crystals into the cells. PMID:27115409

  10. The heterostructured AAO/CeO{sub 2} nanosystem fabricated by electrodeposition for charge storage and hydrophobicity

    He, Geping, E-mail: hqfan3@163.com [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); College of Materials and Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Fan, Huiqing [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Wang, Kaige [Institute of Photonics and Photonic Technology, Northwest University, Xi’an 710069 (China); Yin, Hongfeng [College of Materials and Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Wu, Junjun [Institute of Photonics and Photonic Technology, Northwest University, Xi’an 710069 (China)

    2013-10-01

    Highlights: • Tilted cathode was adopted to fabricate PAAM during the second anodization. • AAO/CeO{sub 2} nanosystem was prepared from PAAM by electrochemical deposition. • The larger the cathode intersection angle, the more the charges are stored in the system. • The system's hydrophobicity was improved by an increase in tilted cathode angle. • The optimum angle of the tilted cathode is 40° for charge storage and hydrophobicity. -- Abstract: Tilted cathode was adopted to prepare porous anodic alumina membrane (PAAM) during the second aluminum anodic oxidation (AAO). A heterostructured AAO/CeO{sub 2} nanosystem was fabricated by filling CeO{sub 2} into the PAAM by electrochemical deposition. The larger the intersection angle of the cathode, the more the charge storage of the fabricated system. A lower potential scan rate is beneficial to the electrochemical charge storage of the system. With the cathode intersection angle increasing, the hydrophobicity of the AAO/CeO{sub 2} system is greatly improved. As the 40° is the optimum angle, the charge storage and hydrophobicity of the system increase with the increasing cathode intersection angle up to 40°. The AAO/CeO{sub 2} system could be utilized in both charge storage and self-cleaning.

  11. Niobium and hafnium grown on porous membranes

    In this work we report on a method for fabricating highly ordered nanostructures of niobium and hafnium metals by physical vapour deposition using two different templates: anodized aluminum oxide membranes (AAO) and zirconium onto AAO membranes (Zr/AAO). The growth mechanism of these metal nanostructures is clearly different depending on the material used as a template. A different morphology was obtained by using AAO or Zr/AAO templates: when the metal is deposited onto AAO membranes, nanospheres with ordered hexagonal regularity are obtained; however, when the metal is deposited onto a Zr/AAO template, highly ordered nanocones are formed. The experimental approach described in this work is simple and suitable for synthesizing nanospheres or nanoholes of niobium and hafnium metals in a highly ordered structure.

  12. Performance and mechanisms for the removal of phthalates and pharmaceuticals from aqueous solution by graphene-containing ceramic composite tubular membrane coupled with the simultaneous electrocoagulation and electrofiltration process.

    Yang, Gordon C C; Chen, Ying-Chun; Yang, Hao-Xuan; Yen, Chia-Heng

    2016-07-01

    In this study, commonly detected emerging contaminants (ECs) in water, including di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), cephalexin (CLX), sulfamethoxazole (SMX) and caffeine (CAF), were selected as the target contaminants. A lab-prepared graphene-containing ceramic composite tubular membrane (TGCCM) coupled with the simultaneous electrocoagulation and electrofiltration process (EC/EF) in crossflow filtration mode was used to remove target contaminants in model solution. Meanwhile, a comparison of the removal efficiency was made among various tubular composite membranes reported, including carbon fibers/carbon/alumina composite tubular membrane (TCCACM), titania/alumina composite tubular membrane (TTACM) and alumina tubular membrane (TAM). The results of this study showed that the removal efficiencies for DnBP and DEHP were 99%, whereas 32-97% for cephalexin (CLX), sulfamethoxazole (SMX) and caffeine (CAF). In this work the mechanisms involved in removing target ECs were proposed and their roles in removing various ECs were also discussed. Further, two actual municipal wastewaters were treated to evaluate the applicability of the aforementioned treatment technology (i.e., TGCCM coupled with EC/EF) to various aqueous solutions in the real world. PMID:27131034

  13. The Software System for the AAO's HERMES Spectrograph

    Shortridge, K.; Farrell, T.; Vuong, M.; Birchall, M.; Heald, R.

    2013-10-01

    The AAO's HERMES spectrograph will start operation in 2013. Its primary project will be a Galactic Archaeology survey that aims to reconstruct the early history of our Galaxy through precise measurements of the chemical abundances of one million stars. This paper describes some of the software aspects of the HERMES project: how it has evolved from the earlier AAO 2dF system, the extensive use of simulation for testing, the overall observing system, and the data reduction pipeline.

  14. Experimental, kinetic and numerical modeling of hydrogen production by catalytic reforming of crude ethanol over a commercial catalyst in packed bed tubular reactor and packed bed membrane reactor

    The demand for hydrogen energy has increased tremendously in recent years essentially because of the increase in the word energy consumption as well as recent developments in fuel cell technologies. The energy information administration has projected that world energy consumption will increase by 59% over the next two decades, from 1999 to 2020, in which the largest share is still dominated by fossil fuels (oil, natural gas and coal). Carbon dioxide (CO2) emissions resulting from the combustion of these fossil fuels currently are estimated to account for three-fourth of human-caused CO2 emissions worldwide. Greenhouse gas emission, including CO2, should be limited, as recommended at the Kyoto Conference, Japan, in December 1997. In this regard, hydrogen (H2) has a significant future potential as an alternative fuel that can solve the problems of CO2 emissions as well as the emissions of other air contaminants. One of the techniques to produce hydrogen is by reforming of hydrocarbons or biomass. Crude ethanol (a form of biomass, which essentially is fermentation broth) is easy to produce, is free of sulphur, has low toxicity, and is also safe to handle, transport and store. In addition, crude ethanol consists of oxygenated hydrocarbons, such as ethanol, lactic acid, glycerol, and maltose. These oxygenated hydrocarbons can be reformed completely to H2 and CO2, the latter of which could be separated from H2 by membrane technology. This provides for CO2 capture for eventual storage or destruction. In the case of using crude ethanol, this will result in negative CO2, emissions. In this paper, we conducted experimental work on production of hydrogen by the catalytic reforming of crude ethanol over a commercial promoted Ni-based catalyst in a packed bed tubular reactor as well as a packed bed membrane reactor. As well, a rigorous numerical model was developed to simulate this process in both the catalytic packed bed tubular reactor and packed bed membrane reactor. The

  15. Application of high speed imaging as a novel tool to study particle dynamics in tubular membrane systems

    Lindeboom, R.; Smith, G.; Jeison, D.; Temmink, H.; Van Lier, J.B.

    2010-01-01

    Membrane bioreactors represent a promising technology for wastewater treatment, already applied to a wide variety of industrial effluents and sewage. Gas or air sparging is a commonly applied approach to generate surface shear to control fouling phenomena and cake formation causing flux reduction. I

  16. Application of high speed imaging as a novel tool to study particle dynamics in tubular membrane systems

    Lindeboom, R.E.F.; Smith, G.; Jeison, D.A.; Temmink, B.G.; Lier, van J.B.

    2011-01-01

    Membrane bioreactors represent a promising technology for wastewater treatment, already applied to a wide variety of industrial effluents and sewage. Gas or air sparging is a commonly applied approach to generate surface shear to control fouling phenomena and cake formation causing flux reduction. I

  17. Fabrication of YBCO nanowires with anodic aluminum oxide (AAO) template

    Dadras, Sedigheh, E-mail: dadras@alzahra.ac.ir; Aawani, Elaheh

    2015-10-15

    We have fabricated YBCO nanowires by using anodic aluminum oxide (AAO) template and sol–gel method, to investigate the fundamental properties of the one-dimensional nanostructure YBCO high-temperature superconductor and enhance its applications. The field-emission scanning electron microscopy and X-ray diffraction pattern results have shown forming of Y-123 nanowires in the template. As an outcome, the YBCO nanowires, prepared by dipping AAO template into YBCO sol method, have average diameter of about 38 nm and length of 1 μm; this is an optimum nanowire sample with larger diameter and length. The resistance–temperature measurement indicates that the onset critical temperature of these samples occurs at 91 K, and the resistance of the optimum sample at onset transition is 10 times lower than the other sample.

  18. STUDY ON TUBULAR ULTRAFILTRATION MEMBRANE DESALINATION PRETREATMENT TECHNOLOGY OF EXTRACTING MAGNESIUM%管式超滤膜海水淡化提镁预处理工艺中试研究

    赵旭臣; 刘恩华

    2011-01-01

    In the pilot process, we studied the tubular ultrafiltration membrane desalination pretreatment technology of extracting magnesium. The relationship among flux rate, runtime and operating pressure had been investigated. Then, the effect of running time on produced water turbidity was also studied .Tested the effect of magnesium extraction of experimental apparatus, and then tubular ultrafiltration membrane of the cleaning method was proposed. The results indicated that tubular ultrafiltration membrane on magnesium in seawater had very good removal efficiency, the produced water could meet the influent water demands of the reverse osmosis. Cleaning method was simple, the recovery rate was relatively high.%对管式超滤膜海水淡化提镁预处理工艺进行了中试研究.考察了产水流量与运行时间、操作压力之间的关系,以及运行时间对产水浊度的影响.并对试验装置的提镁效果进行了测试,同时,提出了管式超滤膜的清洗方法.结果表明,管式超滤膜对海水中的镁有很好的去除效果,产水中的镁含量符合反渗透原水的标准;清洗方法简便,通量恢复率高.

  19. Luminal nucleotides are tonic inhibitors of renal tubular transport

    Leipziger, Jens Georg

    2011-01-01

    in all renal tubular segments and their stimulation generally leads to transport inhibition. Recent evidence has identified the tubular lumen as a restricted space for purinergic signaling. The concentrations of ATP in the luminal fluids are sufficiently high to inflict a tonic inhibition of renal...... necessary for flow-stimulated luminal ATP release. Tubular ATP secretion may occur via nonjunctional connexin-hemichannels (connexin 30), which are strategically placed in the apical membrane of distal tubular intercalated cells and can be activated by tubular flow. SUMMARY: The tubular lumen has been...

  20. The Use of Fibrous, Supramolecular Membranes and Human Tubular Cells for Renal Epithelial Tissue Engineering : Towards a Suitable Membrane for a Bioartificial Kidney

    Dankers, Patricia Y. W.; Boomker, Jasper M.; Huizinga-van der Vlag, Ali; Smedts, Frank M. M.; Harmsen, Martin C.; van Luyn, Marja J. A.

    2010-01-01

    A bioartificial kidney, which is composed of a membrane cartridge with renal epithelial cells, can substitute important kidney functions in patients with renal failure. A particular challenge is the maintenance of monolayer integrity and specialized renal epithelial cell functions ex vivo. We hypoth

  1. Tubular Coupling

    Rosenbaum, Bernard J. (Inventor)

    2000-01-01

    A system for coupling a vascular overflow graft or cannula to a heart pump. A pump pipe outlet is provided with an external tapered surface which receives the end of a compressible connula. An annular compression ring with a tapered internal bore surface is arranged about the cannula with the tapered internal surface in a facing relationship to the external tapered surface. The angle of inclination of the tapered surfaces is converging such that the spacing between the tapered surfaces decreases from one end of the external tapered surface to the other end thereby providing a clamping action of the tapered surface on a cannula which increases as a function of the length of cannula segment between the tapered surfaces. The annular compression ring is disposed within a tubular locking nut which threadedly couples to the pump and provides a compression force for urging the annular ring onto the cannula between the tapered surfaces. The nut has a threaded connection to the pump body. The threaded coupling to the pump body provides a compression force for the annular ring. The annular ring has an annular enclosure space in which excess cannula material from the compression between the tapered surfaces to "bunch up" in the space and serve as an enlarged annular ring segment to assist holding the cannula in place. The clamped cannula provides a seamless joint connection to the pump pipe outlet where the clamping force is uniformly applied to the cannula because of self alignment of the tapered surfaces. The nut can be easily disconnected to replace the pump if necessary.

  2. Platinum-modified SiO{sub 2} with tubular morphology as efficient membrane-type microreactors for mineralization of formic acid

    Anastasescu, Crina; Anastasescu, Mihai; Zaharescu, Maria; Balint, Ioan, E-mail: ibalint@icf.ro [Romanian Academy, Institute of Physical Chemistry (Romania)

    2012-10-15

    SiO{sub 2} amorphous tubes with the internal diameter ranging between 5 and 170 nm and having the aspect ratios typically >50, were prepared using DL-tartaric acid as inorganic template. The tubular SiO{sub 2} was impregnated with a platinum precursor (H{sub 2}PtCl{sub 6}), dried and then reduced with H{sub 2}. The TEM, XPS, FTIR characterization methods revealed that platinum species were located preferentially on the inner walls of tubes having diameter smaller than 100 nm. The walls of SiO{sub 2} nanotubes proved to be amorphous and highly porous, the diameter of pores covering a wide range of radii. The macroporosity of the SiO{sub 2} tubes originated from the open ends of the tubes with the diameter {>=}100 nm, whereas the pores located in the walls of tubes were responsible for the meso and microporosity. Finer Pt nanoparticles (0.9 nm average size) were obtained after the catalyst was dried in air in mild conditions compared to the catalytic material reduced with H{sub 2} (5.3 nm mean size) According to FTIR results, strong metal-support interaction was evidenced between platinum nanoparticles and inner walls of SiO{sub 2} nanotubes. In order to observe the effect of Pt nanoparticle morphology on catalytic behavior, the activity of platinum-modified SiO{sub 2} tubes (1 wt% Pt/SiO{sub 2}) for the oxidation of formic acid to CO{sub 2} was investigated in the 20-75 Degree-Sign C temperature range. The catalytic activity-morphology relationship of Pt/SiO{sub 2} nanotubes was studied and the results were explained in light of experimental results. The catalytic experiments revealed for the first time that SiO{sub 2} nanotubes with highly permeable walls behave as efficient membrane-type microreactors for the oxidation of formic acid to CO{sub 2}. This type of morphological-dependent catalysis may prove to be an efficient tool in near future for the abatement of pollutants in liquid phase.

  3. Fabrication of high quality anodic aluminum oxide (AAO) on low purity aluminum—A comparative study with the AAO produced on high purity aluminum

    Highlights: • Nanoporous alumina was fabricated by anodization in sulfuric acid solution with glycol. • The AAO manufacturing on low- and high-purity Al was compared. • The pores size was ranging between 30 and 50 nm. • No difference in the quality of the AAO fabricated on both Al types was observed. • The current vs. anodization time curves were recorded. -- Abstract: In this work the quality, arrangement, composition, and regularity of nanoporous AAO formed on the low-purity (AA1050) and high-purity aluminum during two-step anodization in a mixture of sulfuric acid solution (0.3 M), water and glycol (3:2, v/v), at various voltages (15, 20, 25, 30, 35 V) and at temperature of −1 °C, are investigated. The electrochemical conditions have allowed to obtain pores with the size ranging from 30 to 50 nm, which are much larger than those usually obtained by anodization in a pure sulfuric acid solution (<20 nm). The mechanism of the AAO growth is discussed. It was found that with the increase of applied anodizing voltage a number of incorporated sulfate ions in the aluminum oxide matrix increases, which was connected with the appearance of an unusual area in the current vs. time curves. On the surface of anodizing low- and high-purity aluminum, the formation of hillocks was observed, which was associated with the sulfate ions incorporation. The sulfate ions are replacing the oxygen atom/atoms in the AAO amorphous crystal structure and, consequently, the AAO template swells, the oxide cracks and uplifts causing the formation of hillocks. The same mechanism occurs for both low- and high-purity aluminum. Nanoporous AAO characterized by a very high regularity, not registered previously for low purity aluminum, was obtained. Furthermore, no significant difference in the regularity ratio between the AAO obtained on low- and high-purity aluminum, was observed. The electrochemical conditions applied in this study can be, thus, used for the fabrication of high quality

  4. Self-assembly of semicrystalline PE-b-PS diblock copolymers within AAO nanoporous templates

    Casas Becerra, María Teresa; Michell, Rose Mary; Blaszczyk-Lezak, Iwona; Puiggalí Bellalta, Jordi; Mijangos, Carmen; Lorenzo, Arnaldo T.; Müller, Alejandro

    2015-01-01

    Strongly segregated polyethylene-b-polystyrene (PE-b-PS) diblock copolymers were infiltrated within anodic aluminum oxide nanoporous templates (AAO) (with 60 nm diameter). After carefully removing the nanofibers from the nanopores, TEM revealed their morphology. This is the first time that the morphology of semi-crystalline diblock copolymers infiltrated within AAO templates is observed. Regardless of their composition, the infiltrated nanofibers are constituted by core–shell or pseudo core–s...

  5. A supramolecular tubular nanoreactor.

    Li, Zhi-Qiang; Zhang, Ying-Ming; Chen, Yong; Liu, Yu

    2014-07-01

    The extremely strong noncovalent complexation between the rigid host of phthalocyanine-bridged β-cyclodextrins and the amphiphilic guest carboxylated porphyrin is employed to construct a hollow tubular structure as a supramolecular nanoreactor. A representative coupling reaction occurs in the hydrophobic interlayers of the tubular walls in pure water at room temperature, leading to an enhancement of ten times higher reaction rate without any adverse effect on catalytic activity and conversion. PMID:24890802

  6. Study on skim milk ultrafiltration with a reciprocating rotating tubular ceramic membrane module%往复旋转管式陶瓷膜超滤脱脂奶水溶液的研究

    张晓娜; 梁志辉; 曾燕艳; 范洪波; 吕斯濠

    2013-01-01

    The reciprocating rotary tubular ceramic membrane filtration system could create high shear rate at the membrane surface repeatedly by rotating membrane module in a reciprocating motion to reduce membrane fouling. Compared with the unidirectional rotating filtration and dead-end filtration under the same conditions,the reciprocating rotary filtration system showed superiority in reducing membrane fouling. This research designed ultrafiltration skim milk solution tests to investigate the influence of operating parameters. The results revealed that feed concentration increase could lead to the decrease of membrane permeate flux,and membrane flux could be reduced once the TMP was too high. The increase of rotating speed could induce the increase of shear enhancement and the membrane permeate flux. As the reciprocating rotating cycle increased,the quasi steady membrane permeate flux firstly increases before it decreased. When the feed fluid velocity was at the membrane module velocity,the membrane module being rotated in opposite direction instantaneously generated the largest shear rate on the membrane surface and gained the largest permeate flux. The specific energy consumption per m3 permeate of the reciprocating rotary filtration system was lower than the unidirectional rotating filtration.%往复旋转管式陶瓷膜过滤系统通过膜组件往复旋转在膜表面反复产生高剪切率,达到减缓膜污染的效果。在相同操作条件下,与单向旋转过滤和死端过滤相比较,往复旋转过滤具有更好的减缓膜污染的作用。本实验利用往复旋转膜过滤装置超滤脱脂奶水溶液,考察了各种参数对该膜系统过滤特性的影响。实验结果表明,料液浓度增大,膜通量减小;过高的操作压差将会抑制膜通量增加;旋转速度增大,膜表面剪切强化作用增强,膜通量相应增大;膜稳态通量随往复旋转周期增大呈现先增大后减小的趋势。当料液速

  7. Growth Mechanism and Optimized Parameters to Synthesize Nation-115 Nanowire Arrays with Anodic Aluminium Oxide Membranes as Templates

    ZHANG Lu; PAN Cao-Feng; ZHU Jing

    2008-01-01

    @@ Nafion-115 nanowire arrays are synthesized with an extrusion method using AAO membranes as templates. It is indicated that the vacuum treating of AAO templates before surface decoration plays an important role in obtaining high filling rate of the Nafion-115 nanowires in the AAO templates, while the concentration of Nafion-115 DMSO solutions does not affect the filling rate greatly. The optimized parameters to synthesize the Nafion-115 nanowire arrays are studied. The filling rate of the Nafion-115 nanowires in the AAO templates synthesized with the optimized parameters is about 95%. The growth mechanism of Nafion-115 nanowires is discussed to qualitatively explain the experimental results.

  8. Influence of wet etching time cycles on morphology features of thin porous Anodic Aluminum oxide (AAO) template for nanostructure's synthesis

    Chahrour, Khaled M.; Ahmed, Naser M.; Hashim, M. R.; Elfadill, Nezar G.; Al-Diabat, Ahmad M.; Bououdina, M.

    2015-12-01

    This study examines the influence of chemical wet etching time cycles on the morphological features of thin porous AAO template. Pore widening via wet-etching treatment at room temperature was found to modify the pore quality of AAO template and reduces the barrier layer on the bottom of AAO pore array in order to facilitate uniform electrodeposition of nanostructures onto AAO template. High quality AAO pore arrays with different mean pore diameters (64, 70, and 87 nm) were prepared under controllable pore-widening time cycles of 10, 30 and 45 min at room temperature, respectively. The AAO templates and the produced Cu nanorods were characterized using FESEM, EDX, XRD and AFM. The results indicate that the morphology of the aligned arrays of Cu nanorods is strongly affected by the duration of etching and the removal of AAO template. This study showed that the optimum etching duration required to maintain the aligned nanorods without any fracture is approximately 5 min. In addition, the regular hemispherical concave Al surface ensuring the self-ordering of AAO pore can be established when striping is employed for 45 min. Thus, it can be inferred that the duration of wet etching treatment (striping) of Al oxide film performed after the first-step anodization plays a vital role in the final arrangement of nanopores.

  9. Método de impregnação química aplicado em tubos microporosos e membranas tubulares para a microfiltração de emulsões e suspensões de bactérias Method of chemical impregnation applied to microporous tubes and tubular membranes for the microfiltration of emulsions and bacteria suspensions

    R. Del Colle

    2008-03-01

    Full Text Available Uma técnica de impregnação química via solução de precursor foi desenvolvida para formação de filmes finos em tubos microporosos e membranas tubulares. O desempenho desta técnica foi analisado no processo de microfiltração de emulsões (óleo vegetal/água e de suspensões de bactérias (Escherichia coli do soro residual do processamento de queijo. Os tubos microporosos (tamanho nominal 0,5 µm foram impregnados com solução precursora de zircônia (e calcinados a 600 e 900 ºC afim de influenciar na melhora do processo de desemulsificação e as membranas cerâmicas (tamanho nominal entre 0,8 µm e 1,2 µm foram impregnadas com precursor (e calcinadas a 600 °C para formação de prata metálica, para agir como bactericida na suspensão residuária de bactérias da indústria de queijo. O meio poroso impregnado foi caracterizado por meio de microscopia eletrônica de varredura. Os resultados da análise do permeado para valores do teor orgânico de carbono são respectivos ao tratamento de emulsões; o valor da contagem de bactérias via análise de plaqueamento é respectivo ao tratamento de suspensão de bactérias. Os resultados foram analisados e discutidos em função do desempenho e da influência da impregnação quanto à presença de zircônia ou prata para cada aplicação.A technique of chemical impregnation by precursor solution was developed for the formation of thin films in microporous tubes and tubular membranes. The performance of this technique was analyzed by the microfiltration process of emulsions (vegetable oil/water and bacteria suspensions (Escherichia coli of the whey of milk of cheese processing. The microporous tubes (nominal pore size 0.5 µm were impregnated with a precursor zirconia solution and calcined at 600 and 900 ºC to influence the improvement of the demulsification process. Ceramic membranes (nominal pore size between 0.8 µm and 1.2 µm were impregnated with a silver precursor and calcined at

  10. Reliability of Tubular Joints

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    In this paper the preliminary results obtained by tests on tubular joints are presented. The joints are T-joints and the loading is static. It is the intention in continuation of these tests to perform tests on other types of joints (e.g. Y-joints) and also with dynamic loading. The purpose of th...

  11. Effects of the voltage and time of anodization on modulation of the pore dimensions of AAO films for nanomaterials synthesis

    Chahrour, Khaled M.; Ahmed, Naser M.; Hashim, M. R.; Elfadill, Nezar G.; Maryam, W.; Ahmad, M. A.; Bououdina, M.

    2015-12-01

    Highly-ordered and hexagonal-shaped nanoporous anodic aluminum oxide (AAO) of 1 μm thickness of Al pre-deposited onto Si substrate using two-step anodization was successfully fabricated. The growth mechanism of the porous AAO film was investigated by anodization current-time behavior for different anodizing voltages and by visualizing the microstructural procedure of the fabrication of AAO film by two-step anodization using cross-sectional and top view of FESEM imaging. Optimum conditions of the process variables such as annealing time of the as-deposited Al thin film and pore widening time of porous AAO film were experimentally determined to obtain AAO films with uniformly distributed and vertically aligned porous microstructure. Pores with diameter ranging from 50 nm to 110 nm and thicknesses between 250 nm and 1400 nm, were obtained by controlling two main influential anodization parameters: the anodizing voltage and time of the second-step anodization. X-ray diffraction analysis reveals amorphous-to-crystalline phase transformation after annealing at temperatures above 800 °C. AFM images show optimum ordering of the porous AAO film anodized under low voltage condition. AAO films may be exploited as templates with desired size distribution for the fabrication of CuO nanorod arrays. Such nanostructured materials exhibit unique properties and hold high potential for nanotechnology devices.

  12. Tubular Secretion in CKD.

    Suchy-Dicey, Astrid M; Laha, Thomas; Hoofnagle, Andrew; Newitt, Rick; Sirich, Tammy L; Meyer, Timothy W; Thummel, Ken E; Yanez, N David; Himmelfarb, Jonathan; Weiss, Noel S; Kestenbaum, Bryan R

    2016-07-01

    Renal function generally is assessed by measurement of GFR and urinary albumin excretion. Other intrinsic kidney functions, such as proximal tubular secretion, typically are not quantified. Tubular secretion of solutes is more efficient than glomerular filtration and a major mechanism for renal drug elimination, suggesting important clinical consequences of secretion dysfunction. Measuring tubular secretion as an independent marker of kidney function may provide insight into kidney disease etiology and improve prediction of adverse outcomes. We estimated secretion function by measuring secreted solute (hippurate, cinnamoylglycine, p-cresol sulfate, and indoxyl sulfate) clearance using liquid chromatography-tandem mass spectrometric assays of serum and timed urine samples in a prospective cohort study of 298 patients with kidney disease. We estimated GFR by mean clearance of creatinine and urea from the same samples and evaluated associations of renal secretion with participant characteristics, mortality, and CKD progression to dialysis. Tubular secretion rate modestly correlated with eGFR and associated with some participant characteristics, notably fractional excretion of electrolytes. Low clearance of hippurate or p-cresol sulfate associated with greater risk of death independent of eGFR (hazard ratio, 2.3; 95% confidence interval, 1.1 to 4.7; hazard ratio, 2.5; 95% confidence interval, 1.0 to 6.1, respectively). Hazards models also suggested an association between low cinnamoylglycine clearance and risk of dialysis, but statistical analyses did not exclude the null hypothesis. Therefore, estimates of proximal tubular secretion function correlate with glomerular filtration, but substantial variability in net secretion remains. The observed associations of net secretion with mortality and progression of CKD require confirmation. PMID:26614381

  13. AFM characterization and electrochemical property of Ag nanowires by modified AAO template method

    Ag nanowires as electrode materials were prepared from modified anodic aluminum oxide (AAO) template method by using dextrose as reductive, and the process of Ag nanowires growth was monitored by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The structure and electrochemical properties of Ag nanowires were characterized by X-ray diffraction (XRD), UV-vis absorption spectra and cyclic voltammograms (CV) measurements. The results show that Ag nanowires prepared from AAO possessed typical face centered cubic structure with average diameter of 60 nm. Furthermore, the CV characterization reveals that Ag nanowires featured a pair of asymmetrical redox peaks with the position near 0.5 V and the microstructure was maintained in electrochemical reaction

  14. Tubular toxicity of proteinuria.

    Baines, Richard J; Brunskill, Nigel J

    2011-03-01

    Proteinuria is a prognostic indicator of progressive kidney disease and poor cardiovascular outcomes. Abnormally filtered bioactive macromolecules interact with proximal tubular epithelial cells (PTECs), which results in the development of proteinuric nephropathy. This condition is characterized by alterations in PTEC growth, apoptosis, gene transcription and inflammatory cytokine production as a consequence of dysregulated signaling pathways that are stimulated by proteinuric tubular fluid. The megalin-cubilin complex mediates the uptake of several proteins, including albumin, into PTECs. Megalin might also possess intrinsic signaling properties and the ability to regulate cell signaling pathways and gene transcription after processing regulated intramembrane proteolysis. Megalin could, therefore, link abnormal PTEC albumin exposure with altered growth factor receptor activation, proinflammatory and profibrotic signaling, and gene transcription. Evidence now suggests that other PTEC pathways for protein reabsorption of (patho)physiological importance might be mediated by the neonatal Fc receptor and CD36. PMID:21151210

  15. Fabrication of vertically aligned Pd nanowire array in AAO template by electrodeposition using neutral electrolyte

    Yüzer Hayrettin

    2010-01-01

    Full Text Available Abstract A vertically aligned Pd nanowire array was successfully fabricated on an Au/Ti substrate using an anodic aluminum oxide (AAO template by a direct voltage electrodeposition method at room temperature using diluted neutral electrolyte. The fabrication of Pd nanowires was controlled by analyzing the current–time transient during electrodeposition using potentiostat. The AAO template and the Pd nanowires were characterized by scanning electron microscopy (SEM, energy-dispersive X-ray (EDX methods and X-Ray diffraction (XRD. It was observed that the Pd nanowire array was standing freely on an Au-coated Ti substrate after removing the AAO template in a relatively large area of about 5 cm2, approximately 50 nm in diameter and 2.5 μm in length with a high aspect ratio. The nucleation rate and the number of atoms in the critical nucleus were determined from the analysis of current transients. Pd nuclei density was calculated as 3.55 × 108 cm−2. Usage of diluted neutral electrolyte enables slower growing of Pd nanowires owing to increase in the electrodeposition potential and thus obtained Pd nanowires have higher crystallinity with lower dislocations. In fact, this high crystallinity of Pd nanowires provides them positive effect for sensor performances especially.

  16. Enhancing the platinum atomic layer deposition infiltration depth inside anodic alumina nanoporous membrane

    Nanoporous platinum membranes can be straightforwardly fabricated by forming a Pt coating inside the nanopores of anodic alumina membranes (AAO) using atomic layer deposition (ALD). However, the high-aspect-ratio of AAO makes Pt ALD very challenging. By tuning the process deposition temperature and precursor exposure time, enhanced infiltration depth along with conformal coating was achieved for Pt ALD inside the AAO templates. Cross-sectional scanning electron microscopy/energy dispersive x-ray spectroscopy and small angle neutron scattering were employed to analyze the Pt coverage and thickness inside the AAO nanopores. Additionally, one application of platinum-coated membrane was demonstrated by creating a high-density protein-functionalized interface

  17. Enhancing the platinum atomic layer deposition infiltration depth inside anodic alumina nanoporous membrane

    Vaish, Amit, E-mail: anv@udel.edu; Krueger, Susan; Dimitriou, Michael; Majkrzak, Charles [National Institute of Standards and Technology (NIST) Center for Neutron Research, Gaithersburg, MD 20899-8313 (United States); Vanderah, David J. [Institute for Bioscience and Biotechnology Research, NIST, Rockville, Maryland 20850 (United States); Chen, Lei, E-mail: lei.chen@nist.gov [NIST Center for Nanoscale Science and Technology, Gaithersburg, Maryland 20899-8313 (United States); Gawrisch, Klaus [Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892 (United States)

    2015-01-15

    Nanoporous platinum membranes can be straightforwardly fabricated by forming a Pt coating inside the nanopores of anodic alumina membranes (AAO) using atomic layer deposition (ALD). However, the high-aspect-ratio of AAO makes Pt ALD very challenging. By tuning the process deposition temperature and precursor exposure time, enhanced infiltration depth along with conformal coating was achieved for Pt ALD inside the AAO templates. Cross-sectional scanning electron microscopy/energy dispersive x-ray spectroscopy and small angle neutron scattering were employed to analyze the Pt coverage and thickness inside the AAO nanopores. Additionally, one application of platinum-coated membrane was demonstrated by creating a high-density protein-functionalized interface.

  18. Classifying Virtually Special Tubular Groups

    Woodhouse, Daniel J.

    2016-01-01

    A group is tubular if it acts on a tree with $\\mathbb{Z}^2$ vertex stabilizers and $\\mathbb{Z}$ edge stabilizers. We prove that a tubular group is virtually special if and only if it acts freely on a locally finite CAT(0) cube complex. Furthermore, we prove that if a tubular group acts freely on a finite dimensional CAT(0) cube complex, then it virtually acts freely on a three dimensional CAT(0) cube complex.

  19. Membraner

    Bach, Finn

    2009-01-01

    Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner......Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner...

  20. Tubular closure mechanism

    This invention relates to a closure mechanism for tubular irradiation surveillance specimen assembly holder used in nuclear reactors. The closure mechanism is composed of a latching member which includes a generally circular chamber with a plurality of elongated latches depending therefrom. The latching member circumscribes part of an actuator member which is disposed within the latching member so as to be axially movable. The axial movement of the actuator actuates positioning of the latches between positions in which the latches are locked and secured within the actuator member. Means, capable of being remotely manipulated, are provided to move the actuator in order to position the latches and load the articles within the tube

  1. Fabrication of nanostructure via self-assembly of nanowires within the AAO template

    Brust Mathias

    2006-01-01

    Full Text Available AbstractThe novel nanostructures are fabricated by the spatial chemical modification of nanowires within the anodic aluminum oxide (AAO template. To make the nanowires better dispersion in the aqueous solution, the copper is first deposited to fill the dendrite structure at the bottom of template. During the process of self-assembly, the dithiol compound was used as the connector between the nanowires and nanoparticles by a self-assembly method. The nanostructures of the nano cigars and structure which is containing particles junction are characterized by transmission electron microscopy (TEM. These kinds of novel nanostructure will be the building blocks for nanoelectronic and nanophotonic devices.

  2. Partial oxidation of methane to syngas in tubular oxygenpermeable reactor

    2002-01-01

    A dense Ba0.5Sr0.5Co0.8Fe0.2O3-δ membrane tube was prepared by the extruding method. Furthermore, a membrane reactor with this tubular membrane was successfully applied to partial oxidation of methane (POM) reaction,in which the separation of oxygen from air and the partial oxidation of methane are integrated in one process. At 875℃,94% of methane conversion, 98% of CO selectivity, 95% of H2 selectivity, and as high as 8.8 mL/(min @cm2) of oxygen flux were obtained. In POM reaction condition, the membrane tube shows a very good stability.

  3. Impedance spectroscopy of highly ordered nano-porous electrodes based on Au-AAO (anodic aluminum oxide) structure.

    Ahn, Jaehwan; Cho, Sungbo; Min, Junhong

    2013-11-01

    Electrochemical measurements using the microelectrodes are increasingly utilized for the label-free detection of the small amount of biological materials such as DNA, protein, and cells. However, the interfacial electrode impedance increases and may hinder the detection of weak signals as the size of electrode decreases. To enhance the measurement sensitivity while reducing the electrode size, in this study, microelectrodes employing a nanoporous structure were fabricated and characterized by using electrical impedance spectroscopy. We made the highly ordered honeycomb nanoporous structure of Anodic Aluminum Oxide (AAO) by electrochemical anodizing and formed Au layer on the surface of AAO (Au/AAO) by electroless Au plating method. The electrical characteristics of the fabricated Au/AAO electrodes were evaluated by using de Levie's model derived for the pore electrodes. As a result, the interfacial electrode impedance of the fabricated Au/AAO electrodes was 2-3 order lower than the value of the planar electrodes at frequencies below 1 kHz. It implies this nanoporous electrode could be directly applied to label free detection of biomaterials. PMID:24245278

  4. Flux calibration of the AAO/UKST SuperCOSMOS H-alpha Survey

    Frew, David J; Parker, Quentin A; Pierce, Mark J; Gunawardhana, M L P; Reid, W A

    2013-01-01

    The AAO/UKST SuperCOSMOS H-alpha Survey (SHS) of the southern Galactic plane was, when completed in 2003, a powerful new addition to wide-field surveys. It has a combination of areal coverage, spatial resolution and flux sensitivity in a narrow imaging band which still marks it out today as an excellent resource for the astronomical community. The 233 separate fields are available online in digital form, with each field covering 25 square degrees. The SHS has been the motivation for equivalent surveys in the north, and new digital H-alpha surveys now beginning in the south such as VPHAS+. The SHS has been the foundation of many important follow-up discovery projects in the southern sky with the Macquarie/AAO/Strasbourg H-alpha (MASH) planetary nebula project being a particularly successful example. However, the full astrophysical potential of the SHS has been hampered by lack of a clear route to acceptable flux calibration from the base photographic data. We have determined the calibration factors for 170 sep...

  5. DC electrodeposition of NiGa alloy nanowires in AAO template

    NiGa alloy nanowires were electrodeposited from an acidic sulfate bath into nanoporous anodized alumina oxide (AAO). This template was fabricated by two-step anodizing. The effects of bath composition and current density were explored on the Ga content of electrodeposited nanowires. The Ga content in the deposits was increased by increasing both Ga in the bath composition and electrodepositing current density. The NiGa alloy nanowires were synthesized for Ga content up to 2–4% without significant improving the magnetic properties. Above this threshold Ga clusters were formed and decreased the magnetic properties of the nanowires. For Ga content of the alloy above 30%, the wires were too short and incomplete. X-ray diffraction patterns reveal that the significant increase of Ga content in the nanowires, changes the FCC crystal structure of Ni to an amorphous phase. It also causes a sizeable increase in the Ga cluster size; these both lead to a significant reduction in the coercivity and the magnetization respectively. - Highlights: • NiGa alloy nanowires were electrodeposited from acidic sulphate baths into nanoporous anodized alumina oxide (AAO) template. • The Ga content was increased by increasing the Ga in the bath composition and electrodeposition current density. • The magnetic parameters such as coercivity and magnetization were not changed for the alloy nanowire with Ga content less than 4%

  6. DC electrodeposition of NiGa alloy nanowires in AAO template

    Maleki, K. [Nanomaterials Group, Department of Materials Engineering, Tarbiat Modares University, Iran, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Sanjabi, S., E-mail: sanjabi@modares.ac.ir [Nanomaterials Group, Department of Materials Engineering, Tarbiat Modares University, Iran, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Alemipour, Z. [Department of Physics, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2015-12-01

    NiGa alloy nanowires were electrodeposited from an acidic sulfate bath into nanoporous anodized alumina oxide (AAO). This template was fabricated by two-step anodizing. The effects of bath composition and current density were explored on the Ga content of electrodeposited nanowires. The Ga content in the deposits was increased by increasing both Ga in the bath composition and electrodepositing current density. The NiGa alloy nanowires were synthesized for Ga content up to 2–4% without significant improving the magnetic properties. Above this threshold Ga clusters were formed and decreased the magnetic properties of the nanowires. For Ga content of the alloy above 30%, the wires were too short and incomplete. X-ray diffraction patterns reveal that the significant increase of Ga content in the nanowires, changes the FCC crystal structure of Ni to an amorphous phase. It also causes a sizeable increase in the Ga cluster size; these both lead to a significant reduction in the coercivity and the magnetization respectively. - Highlights: • NiGa alloy nanowires were electrodeposited from acidic sulphate baths into nanoporous anodized alumina oxide (AAO) template. • The Ga content was increased by increasing the Ga in the bath composition and electrodeposition current density. • The magnetic parameters such as coercivity and magnetization were not changed for the alloy nanowire with Ga content less than 4%.

  7. General Construction of Tubular Geometry

    Mukhopadhyay, Partha

    2016-01-01

    We consider the problem of locally describing tubular geometry around a submanifold embedded in a (pseudo)Riemannian manifold in its general form. Given the geometry of ambient space in an arbitrary coordinate system and equations determining the submanifold in the same system, we compute the tubular expansion coefficients in terms of this {\\it a priori data}. This is done by using an indirect method that crucially applies the tubular expansion theorem for vielbein previously derived. With an explicit construction involving the relevant coordinate and non-coordinate frames we verify consistency of the whole method up to quadratic order in vielbein expansion. Furthermore, we perform certain (long and tedious) higher order computation which verifies the first non-trivial spin connection term in the expansion for the first time. Earlier a similar method was used to compute tubular geometry in loop space. We explain this work in the light of our general construction.

  8. Abrasion resistant tubular member

    A surface of a tubular member made of an austenite stainless steel having a molybdenum content of from 2 to 3% is subjected to a low temperature ionization nitriding treatment in a gas atmosphere of N2: from 5 to 15% by volume, H2: from 95 to 85% by volume, at a temperature of from 400 to 470degC to form a nitride layer. Since the low temperature ion nitriding treatment is thus applied, generation of ε phase which lowers corrosion resistance can be suppressed. That is, the hardened layer (nitride layer) is provided with abrasion resistance, while the inside can keep the inherent characteristic of the austenite stainless steel having high toughness. In addition, this can avoid the tendency of lowering corrosion resistance due to the formation of a ε phase caused by exposure to high temperature for a long time in order to increase the thickness of the nitrided layer. When the thickness of the tube is 1.3mm, the less than 130μm is enough for the nitride layer. Abrasion resistance can be improved by thus applying ion nitriding treatment to the austenite stainless steel containing molybdenum under controlled temperature and atmosphere. (N.H.)

  9. Stem cell factor expression after renal ischemia promotes tubular epithelial survival.

    Geurt Stokman

    Full Text Available BACKGROUND: Renal ischemia leads to apoptosis of tubular epithelial cells and results in decreased renal function. Tissue repair involves re-epithelialization of the tubular basement membrane. Survival of the tubular epithelium following ischemia is therefore important in the successful regeneration of renal tissue. The cytokine stem cell factor (SCF has been shown to protect the tubular epithelium against apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: In a mouse model for renal ischemia/reperfusion injury, we studied how expression of c-KIT on tubular epithelium and its ligand SCF protect cells against apoptosis. Administration of SCF specific antisense oligonucleotides significantly decreased specific staining of SCF following ischemia. Reduced SCF expression resulted in impaired renal function, increased tubular damage and increased tubular epithelial apoptosis, independent of inflammation. In an in vitro hypoxia model, stimulation of tubular epithelial cells with SCF activated survival signaling and decreased apoptosis. CONCLUSIONS/SIGNIFICANCE: Our data indicate an important role for c-KIT and SCF in mediating tubular epithelial cell survival via an autocrine pathway.

  10. Nickel sulfide nanotubes formed by a directional infiltration self-assembly route in AAO templates

    Nickel sulfide nanotube was successfully synthesized by a directional infiltration self-assembly route in AAO templates. The self-assembly process mainly involves infiltration, decomposition and crystal growth in nanochannels, in which dimethyl sulfoxide (DMSO) first acts as both sulfur source and unique infiltrator. For increasing S atom content in nickel sulfides thiourea was also used as additional sulfur source. Scanning electron microscope images (SEM) revealed that the nanotubes have uniform length distributions, several tens micrometers lengths and ultrathin tube-walls of 20 nm thickness. The nanotubes were confirmed by X-ray diffraction (XRD) and Raman spectroscopy, showing hexagonal Ni3S2, α-NiS and cubic NiS2, respectively. The magnetic hysteresis scan of NiS2 NTs showed weak ferromagnetism at room temperature. Its growth mechanism was discussed and proposed as well

  11. Effect of electrolyte temperature on the thickness of anodic aluminium oxide (AAO layer

    P. Michal

    2016-07-01

    Full Text Available Effect of electrolyte temperature on the thickness of resulting oxide layer has been studied. Unlike previous published studies this article was aimed to monitor the relationship between electrolyte temperature and resulting AAO layer thickness in interaction with other input factors affecting during anodizing process under special process condition, i.e. lower concentration of sulphuric acid, oxalic acid, boric acid and sodium chloride. According to Design of Experiments (DOE 80 individual test runs of experiment were carried out. Using statistical analysis and artificial intelligence for evaluation, the computational model predicting the thickness of oxide layer in the range from 5 / μm to 15 / μm with tolerance ± 0,5 / μm was developed.

  12. Flux calibration of the AAO/UKST SuperCOSMOS Hα Survey

    Frew, David J.; Bojičić, Ivan S.; Parker, Quentin A.; Pierce, Mark J.; Gunawardhana, M. L. P.; Reid, W. A.

    2014-05-01

    The AAO/UKST SuperCOSMOS Hα Survey (SHS) was, when completed in 2003, a powerful addition to extant wide-field surveys. The combination of areal coverage, spatial resolution and sensitivity in a narrow imaging band, still marks it out today as an excellent resource for the astronomical community. The 233 separate fields are available online in digital form, with each field covering 25 deg2. The SHS has been the motivation for equivalent surveys in the north, and new digital Hα surveys now beginning in the south such as VPHAS+. It has been the foundation of many important discovery projects with the Macquarie/AAO/Strasbourg Hα planetary nebula project being a particularly successful example. However, the full potential of the SHS has been hampered by lack of a clear route to acceptable flux calibration from the base photographic data. We have determined the calibration factors for 170 individual SHS fields, and present a direct pathway to the measurement of integrated Hα fluxes and surface brightnesses for resolved nebulae detected in the SHS. We also include a catalogue of integrated Hα fluxes for >100 planetary and other nebulae measured from the SHS, and use these data to show that fluxes, accurate to ±0.10-0.14 dex (˜25-35 per cent), can be obtained from these fields. For the remaining 63 fields, a mean calibration factor of 12.0 counts pixel-1 R-1 can be used, allowing the determination of reasonable integrated fluxes accurate to better than ±0.2 dex (˜50 per cent). We outline the procedures involved and the caveats that need to be appreciated in achieving such flux measurements. This paper forms a handy reference source that will significantly increase the scientific utility of the SHS.

  13. Fabrication of Pd-Fe nanowires with a high aspect ratio by AAO template-assisted electrodeposition

    Research highlights: → Vertically oriented Pd0.86Fe0.14 nanowires have been fabricated in an AAO template using electrodeposition method at room temperature. → Pd-Fe alloy nanowires are approximately 65 nm in diameter and 10 μm in length with an aspect ratio of 153. → The structural characterization of Pd-Fe alloy nanowires is done with SEM, EDX and XRD. - Abstract: In this study, vertically oriented Pd0.86Fe0.14 nanowires have been fabricated using an anodized aluminum oxide (AAO) template by direct voltage electrodeposition at room temperature. AAO template-assisted electrodeposition of Pd-Fe was carried out in Pd(NH3)2Cl2:FeSO4.7H2O solution. The AAO template and the Pd0.86Fe0.14 nanowires were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) methods and X-ray diffraction (XRD). It was observed that the Pd0.86Fe0.14 nanowires were approximately 65 nm in diameter and 10 μm in length with an aspect ratio of 153 in a relatively large area of about 4 cm2. The nucleation rate and the number of atoms in the critical nucleus are determined from the analysis of current transients.

  14. Tubular lysosome morphology and distribution within macrophages depend on the integrity of cytoplasmic microtubules

    Swanson, J.; Bushnell, A.; Silverstein, S.C.

    1987-04-01

    Pinocytosis of the fluorescent dye lucifer yellow labels elongated, membrane-bound tubular organelles in several cell types, including cultured human monocytes, thioglycolate-elicited mouse peritoneal macrophages, and the macrophage-like cell line J774.2. These tubular structures can be identified as lysosomes by acid phosphatase histochemistry and immunofluorescence localization of cathepsin L. The abundance of tubular lysosomes is markedly increased by treatment with phorbol 12-myristate 13-acetate. When labeled by pinocytosis of microperoxidase and examined by electron microscopic histochemistry, the tubular lysosomes have an outside diameter of approx. = 75 nm and a length of several micrometers; they radiate from the cell's centrosphere in alignment with cytoplasmic microtubules and intermediate filaments. Incubation of phorbol myristate acetate-treated macrophages at 4/sup 0/C or in medium containing 5 ..mu..M colchicine or nocodazole at 37/sup 0/C leads to disassembly of microtubules and fragmentation of the tubular lysosomes. Return of the cultures to 37/sup 0/C or removal of nocodazole from the medium leads to reassembly of microtubules and the reappearance of tubular lysosomes within 10-20 min. The authors conclude that microtubules are essential for the maintenance of tubular lysosome morphology and that, in macrophages, a significant proportion of the lysosomal compartment is contained within these tubular structures.

  15. Tubular lysosome morphology and distribution within macrophages depend on the integrity of cytoplasmic microtubules

    Pinocytosis of the fluorescent dye lucifer yellow labels elongated, membrane-bound tubular organelles in several cell types, including cultured human monocytes, thioglycolate-elicited mouse peritoneal macrophages, and the macrophage-like cell line J774.2. These tubular structures can be identified as lysosomes by acid phosphatase histochemistry and immunofluorescence localization of cathepsin L. The abundance of tubular lysosomes is markedly increased by treatment with phorbol 12-myristate 13-acetate. When labeled by pinocytosis of microperoxidase and examined by electron microscopic histochemistry, the tubular lysosomes have an outside diameter of ≅ 75 nm and a length of several micrometers; they radiate from the cell's centrosphere in alignment with cytoplasmic microtubules and intermediate filaments. Incubation of phorbol myristate acetate-treated macrophages at 40C or in medium containing 5 μM colchicine or nocodazole at 370C leads to disassembly of microtubules and fragmentation of the tubular lysosomes. Return of the cultures to 370C or removal of nocodazole from the medium leads to reassembly of microtubules and the reappearance of tubular lysosomes within 10-20 min. The authors conclude that microtubules are essential for the maintenance of tubular lysosome morphology and that, in macrophages, a significant proportion of the lysosomal compartment is contained within these tubular structures

  16. Preparation of thin hexagonal highly-ordered anodic aluminum oxide (AAO) template onto silicon substrate and growth ZnO nanorod arrays by electrodeposition

    Chahrour, Khaled M.; Ahmed, Naser M.; Hashim, M. R.; Elfadill, Nezar G.; Qaeed, M. A.; Bououdina, M.

    2014-12-01

    In this study, anodic aluminum oxide (AAO) templates of Aluminum thin films onto Ti-coated silicon substrates were prepared for growth of nanostructure materials. Hexagonally highly ordered thin AAO templates were fabricated under controllable conditions by using a two-step anodization. The obtained thin AAO templates were approximately 70 nm in pore diameter and 250 nm in length with 110 nm interpore distances within an area of 3 cm2. The difference between first and second anodization was investigated in details by in situ monitoring of current-time curve. A bottom barrier layer of the AAO templates was removed during dropping the voltage in the last period of the anodization process followed by a wet etching using phosphoric acid (5 wt%) for several minutes at ambient temperature. As an application, Zn nanorod arrays embedded in anodic alumina (AAO) template were fabricated by electrodeposition. Oxygen was used to oxidize the electrodeposited Zn nanorods in the AAO template at 700 °C. The morphology, structure and photoluminescence properties of ZnO/AAO assembly were analyzed using Field-emission scanning electron microscope (FESEM), Energy dispersive X-ray spectroscopy (EDX), Atomic force microscope (AFM), X-ray diffraction (XRD) and photoluminescence (PL).

  17. Effects of anodic aluminum oxide membrane on performance of nanostructured solar cells

    Dang, Hongmei; Singh, Vijay

    2015-05-01

    Three nanowire solar cell device configurations have been fabricated to demonstrate the effects of the host anodized aluminum oxide (AAO) membrane on device performance. The three configurations show similar transmittance spectra, indicating that AAO membrane has negligible optical absorption. Power conversion efficiency (PCE) of the device is studied as a function of the carrier transport and collection in cell structures with and without AAO membrane. Free standing nanowire solar cells exhibit PCE of 9.9%. Through inclusion of AAO in solar cell structure, interface defects and traps caused by humidity and oxygen are reduced, and direct contact of CdTe tentacles with SnO2 and formation of micro shunt shorts are prevented; hence PCE is improved to 11.1%-11.3%. Partially embedded nanowire solar cells further reduce influence of non-ideal and non-uniform nanowire growth and generate a large amount of carriers in axial direction and also a small quantity of carriers in lateral direction, thus becoming a promising solar cell structure. Thus, including AAO membrane in solar cell structure provides favorable electro-optical properties as well as mechanical advantages.

  18. Renal tubular acidosis and nerve deafness.

    Dunger, D B; Brenton, D. P.; Cain, A R

    1980-01-01

    Two brothers are described with renal tubular acidosis and nerve deafness: the elder also had rickets and hypokalaemia. The parents were unaffected. Studies of urinary acidification and bicarbonate excretion were consistent with a distal tubular abnormality. This report strengthens the view previously proposed in similar cases that nerve deafness and renal tubular acidosis constitute a genetic entity. Examination for nerve deafness is indicated in any child with renal tubular acidosis.

  19. The Sydney-AAO Multi-object Integral field spectrograph (SAMI)

    Croom, Scott M; Bland-Hawthorn, Joss; Bryant, Julia J; Fogarty, Lisa; Richards, Samuel; Goodwin, Michael; Farrell, Tony; Miziarski, Stan; Heald, Ron; Jones, D Heath; Lee, Steve; Colless, Matthew; Brough, Sarah; Hopkins, Andrew M; Bauer, Amanda E; Birchall, Michael N; Ellis, Simon; Horton, Anthony; Leon-Saval, Sergio; Lewis, Geraint; Lopez-Sanchez, A R; Min, Seong-Sik; Trinh, Christopher; Trowland, Holly

    2011-01-01

    We demonstrate a novel technology that combines the power of the multi-object spectrograph with the spatial multiplex advantage of an integral field spectrograph (IFS). The Sydney-AAO Multi-object IFS (SAMI) is a prototype wide-field system at the Anglo-Australian Telescope (AAT) that allows 13 imaging fibre bundles ("hexabundles") to be deployed over a 1-degree diameter field of view. Each hexabundle comprises 61 lightly-fused multimode fibres with reduced cladding and yields a 75 percent filling factor. Each fibre core diameter subtends 1.6 arcseconds on the sky and each hexabundle has a field of view of 15 arcseconds diameter. The fibres are fed to the flexible AAOmega double-beam spectrograph, which can be used at a range of spectral resolutions (R=lambda/delta(lambda) ~ 1700-13000) over the optical spectrum (3700-9500A). We present the first spectroscopic results obtained with SAMI for a sample of galaxies at z~0.05. We discuss the prospects of implementing hexabundles at a much higher multiplex over wid...

  20. Role of AAO template filling process parameters in controlling the structure of one-dimensional polymer nanoparticles

    Solution template wetting is a common technique used to fabricate elongated polymer nanostructures; however, the parameters controlling the resulting morphology remain unclear. The purpose of this investigation was to elucidate the effects of process variables on the types of nanostructures obtained and to understand the physical mechanisms associated with structure development. 1 wt% polystyrene-THF solutions were infiltrated into commercial and homemade anodized aluminum oxide (AAO) templates. The wetting interaction between the AAO template and the polymer solution was examined through contact angle measurements. In general, for moderate dipping times (<18 h), the morphology of the nanopolymer was rod-like at low molecular weights, while tubes were observed at high molecular weight, even at this low concentration. Nanorods were obtained for all molecular weights for extended dipping times. The data suggest that phase separated layers may grow sequentially from the pore walls and yield nanotubes if the growth is interrupted or produce nanorods for unhindered deposition over long periods.

  1. Miopatias associadas a agregados tubulares

    Mary Souza Carvalho

    1993-09-01

    Full Text Available Os autores relatam a caso de paciente de 58 anos de idade do sexo masculino, com quadro de características miastênicas tanto clínica como eletromiograficamente, no qual a biópsia muscular com histoquímica e microscopia eletrônica permitiu fazer o diagnostico de miopatia associada a agregados tubulares. É chamada a atenção para o fato de que as alterações anátomo-patológicas encontradas podem estar presentes em um grupo heterogêneo de pacientes com grande variedade de sintomas, não havendo portanto motivo para considerar-se a existência de uma miopatia com agregados tubulares, já que os achados anátomo-patológicos são inespecíficos e não configuram moléstia específica.

  2. Tubular crystals of acetylcholine receptor

    1984-01-01

    Well-ordered tubular crystals of acetylcholine receptor were obtained from suspensions of Torpedo marmorata receptor-rich vesicles. They are composed of pairs of oppositely oriented molecules arranged on the surface lattice with the symmetry of the plane group p2 (average unit cell dimensions: a = 90 A, b = 162 A, gamma = 117 degrees). The receptor in this lattice has an asymmetric distribution of mass around its perimeter, yet a regular pentagonal shape; thus its five transmembrane subunits ...

  3. Modified tubularized incised plate urethroplasty

    Shivaji Mane; Jamir Arlikar; Nitin Dhende

    2013-01-01

    Aim: To share our experience of doing tubularized incised plate urethroplasty with modifications. Materials and Methods: This is a single surgeon personal series from 2004 to 2009. One hundred patients of distal hypospadias were subjected for Snodgrass urethroplasty with preputioplasty. The age range was 1 to 5 year with mean age of 2.7 years. Selection criteria were good urethral plate, without chordee and torsion needing complete degloving. Main technical modification from original Snodgras...

  4. Three-dimensional nanotube electrode arrays for hierarchical tubular structured high-performance pseudocapacitors.

    Gao, Yuan; Lin, Yuanjing; Chen, Jiaqi; Lin, Qingfeng; Wu, Yue; Su, Wenjun; Wang, Wenli; Fan, Zhiyong

    2016-07-21

    Ordered three-dimensional (3-D) tubular arrays are highly attractive candidates for high performance pseudocapacitor electrodes. Here, we report 3-D fluorine doped tin oxide (FTO) tubular arrays fabricated by a cost-effective ultrasonic spray pyrolysis (USP) method in anodic aluminum oxide (AAO) channels with high uniformity. The large surface area of such a structure leads to remarkable surface area enhancement up to 51.8 times compared to a planar structure. Combining with electrochemically deposited manganese dioxide (MnO2) nanoflakes on the inner side wall of the FTO nanotubes, the unique hierarchical tubular structured pseudocapacitor electrode demonstrated the highest areal capacitance of 193.8 mF cm(-2) at the scan rate of 5 mV s(-1) and 184 mF cm(-2) at the discharge current density of 0.6 mA cm(-2), which is 18.5 times that of a planar electrode. And it also showed a volumetric capacitance of 112.6 F cm(-3) at the scan rate of 5 mV s(-1) and 108.8 F cm(-3) at the discharge current density of 0.6 mA cm(-2). In addition, the cyclic stability test also indicated that a nanostructured pseudocapacitive electrode has a much larger capacitance retention after 3000 cycles of the charge-discharge process compared with a planar electrode, primarily due to the mechanical stability of the nanostructure. Moreover, pseudocapacitor device fabrication based on such electrodes shows the volumetric capacitance of 17.5 F cm(-3), and the highest specific energy of 1.56 × 10(-3) Wh cm(-3). With the merit of facile fabrication procedures and largely enhanced electrochemical performance, such a 3-D structure has high potency for energy storage systems for a wide range of practical applications. PMID:27337295

  5. Design and Operation of Multi-mode AAO/ABF Process at Fuyong Sewage Treatment Plant in Shenzhen%深圳福永污水厂多模式AAO/ABF工艺设计与运行

    鄢卫东

    2013-01-01

    The recent treatment capacity of Fuyong Sewage Treatment Plant is 12. 5 × 10 m /d, the secondary treatment uses multi-mode AAO process, and the advanced treatment uses the automatic backwash fdter ( ABF). The effluent quality meets the first class A criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant ( GB 18918 - 2002). The process flow, design parameters, technical characteristics and running effect of the project were introduced. sewage treatment plant; AAO; nitrogen and phosphorus removal; automatic%深圳福永污水处理厂近期处理规模为12.5×104 m3/d,二级处理采用了多模式AAO工艺,深度处理采用自动反冲洗滤池(ABF),出水水质满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准.详细介绍了该工程工艺流程及设计参数、技术特点和运行效果.

  6. Modified tubularized incised plate urethroplasty

    Shivaji Mane

    2013-01-01

    Full Text Available Aim: To share our experience of doing tubularized incised plate urethroplasty with modifications. Materials and Methods: This is a single surgeon personal series from 2004 to 2009. One hundred patients of distal hypospadias were subjected for Snodgrass urethroplasty with preputioplasty. The age range was 1 to 5 year with mean age of 2.7 years. Selection criteria were good urethral plate, without chordee and torsion needing complete degloving. Main technical modification from original Snodgrass procedure was spongioplasty, preputioplasty, and dorsal slit when inability to retract prepuce during surgery. Results: Average follow-up period is 23 months. Seven (7% patients developed fistula and one patient had complete preputial dehiscence. Phimosis developed in three (3% patients and required circumcision. Dorsal slit was required in seven patients. One patient developed meatal stenosis in postoperative period. All other patients are passing single urinary stream and have cosmesis that is acceptable. Conclusions: Modified tubularized incised plate urethroplasty with preputioplasty effectively gives cosmetically normal looking penis with low complications.

  7. Effect of anneal pre-treatment of polycrystalline aluminum sheets on synthesis of highly-ordered anodic aluminum oxide membranes

    2008-01-01

    Anodic aluminum oxide (AAO) membranes with large ordered pore domains were successfully prepared by adopting the anneal pre-treatment of polycrystalline alu- minum sheets. A statistical method with Gaussian distribution was introduced to quantitatively study the size of the domain with ordered pores. The largest average area of ordered pore domains was 2.6 μm2±0.11 μm2. The corresponding AAO membrane was synthesized by aluminum sheets annealed at 893 K for 24 h.

  8. Tubular lining material for pipelines having bends

    Moringa, A.; Sakaguchi, Y.; Hyodo, M.; Yagi, I.

    1987-03-24

    A tubular lining material for pipelines having bends or curved portions comprises a tubular textile jacket made of warps and wefts woven in a tubular form overlaid with a coating of a flexible synthetic resin. It is applicable onto the inner surface of a pipeline having bends or curved portions in such manner that the tubular lining material with a binder onto the inner surface thereof is inserted into the pipeline and allowed to advance within the pipeline, with or without the aid of a leading rope-like elongated element, while turning the tubular lining material inside out under fluid pressure. In this manner the tubular lining material is applied onto the inner surface of the pipeline with the binder being interposed between the pipeline and the tubular lining material. The lining material is characterized in that a part of all of the warps are comprised of an elastic yarn around which, over the full length thereof, a synthetic fiber yarn or yarns have been left-and/or right-handedly coiled. This tubular lining material is particularly suitable for lining a pipeline having an inner diameter of 25-200 mm and a plurality of bends, such as gas service pipelines or house pipelines, without occurrence of wrinkles in the lining material in a bend.

  9. Progress in Nano-Engineered Anodic Aluminum Oxide Membrane Development

    Gerrard Eddy Jai Poinern

    2011-02-01

    Full Text Available The anodization of aluminum is an electro-chemical process that changes the surface chemistry of the metal, via oxidation, to produce an anodic oxide layer. During this process a self organized, highly ordered array of cylindrical shaped pores can be produced with controllable pore diameters, periodicity and density distribution. This enables anodic aluminum oxide (AAO membranes to be used as templates in a variety of nanotechnology applications without the need for expensive lithographical techniques. This review article is an overview of the current state of research on AAO membranes and the various applications of nanotechnology that use them in the manufacture of nano-materials and devices or incorporate them into specific applications such as biological/chemical sensors, nano-electronic devices, filter membranes and medical scaffolds for tissue engineering.

  10. Individual electrostatic astigmatic tubular lenses

    Electron-optical properties of three-electrode individual astigmatic tubular lenses with similar electrode diameters are investigated. It has been assumed while calculations that gaps between the el ctrodes are infinitely small and lines separating them are presented as part of line of intersection of two cylinders with equal radius. Parameters characterizing paraxial properties of lenses and coefficients of their spherical aberration for subject position on the infinity at different ratios of electrode potential and distances between gaps are determined. The three-electrode individual lens focuses charged particle beams in one plain and it scatters them in another one in the whole chosen range of potential ratios. It is revealed that coefficients of spherical aberration in individual lenses have different signs and one of the coefficients passes through zero

  11. Characterization of Anodic Aluminum Oxide Membrane with Variation of Crystallizing Temperature for pH Sensor.

    Yeo, Jin-Ho; Lee, Sung-Gap; Jo, Ye-Won; Jung, Hye-Rin

    2015-11-01

    We fabricated electrolyte-dielectric-metal (EDM) device incorporating a high-k Al2O3 sensing membrane from a porous anodic aluminum oxide (AAO) using a two step anodizing process for pH sensors. In order to change the properties of the AAO template, the crystallizing temperature was varied from 400 degrees C to 700 degrees C over 2 hours. The structural properties were observed by field emission scanning electron microscopy (FE-SEM). The pH sensitivity increased with an increase in the crystallizing temperature from 400 degrees C to 600 degrees C. However at 700 degrees C, deformation occurred. The porous AAO sensor with a crystallizing temperature of 600 degrees C displayed the good sensitivity and long-term stability and the values were 55.7 mV/pH and 0.16 mV/h, respectively. PMID:26726567

  12. Ileal bladder substitute: antireflux nipple or afferent tubular segment?

    Studer, U E; Spiegel, T; Casanova, G A; Springer, J; Gerber, E; Ackermann, D K; Gurtner, F; Zingg, E J

    1991-01-01

    Spheroidal bladder substitutes made from double-folded ileal segments, similar to Goodwin's cup-patch technique, are devoid of major coordinated wall contractions. This, together with the reservoir's direct anastomosis to the membranous urethra, prevents major intraluminal pressure peaks and assures a residue-free voiding of sterile urine. In order to determine whether, under these conditions, an afferent tubular isoperistaltic ileal segment of 20-cm length protects the upper urinary tract as efficiently as an antireflux nipple, 60 male patients who were subjected to radical cystectomy were prospectively randomised to groups in which a bladder substitute was formed together with either of these 2 antireflux devices. An analysis of the results obtained in 20 patients from each group who could be followed for more than 1 year (median observation time 30 and 36 months) showed no differences between the groups in metabolic disturbances, kidney size, reservoir capacity, diurnal and nocturnal urinary continence, the incidence of urinary tract infection or episodes of acute pyelonephritis. Later than 1 year postoperatively, intravenous urograms of the renoureteral units of 25% of the patients with antireflux nipples showed persistent but generally slight dilatation of the upper urinary tracts. This observation was significantly more frequent than it was in patients with afferent tubular segments. Urodynamic and radiographic studies showed that the competence of the antireflux nipples was secured by the raised surrounding intravesical pressure. This, however, also resulted in a transient functional obstruction, and a gradual rise of the basal pressure in the upper urinary tracts was recorded. In patients with afferent ileal tubular segments, contrast medium could be forced upwards into the renal pelvis when the bladder substitutes were overfilled. However, despite raised intravesical pressures, peristalsis in the isoperistaltic afferent tubular segment gradually returned

  13. Studying the effect of material parameters on cell performance of tubular-shaped PEM fuel cell

    Al-Baghdadi, Maher A.R. Sadiq [Department of Mechanical Engineering, International Technological University, 115 Dollis Hill Lane, London NW2 6HS (United Kingdom)

    2008-11-15

    A full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena in a PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, transport and phase change mechanism of water, and potential fields. The model is shown to be able to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. In addition to the new feature of tubular-shaped geometry of PEM fuel cell, this model is used to study the effects of several material parameters on fuel cell performance. Detailed analyses of the temperature distribution inside the tubular cell under various material properties have been conducted and examined. The analysis helped identifying critical parameters and shed insight into the physical mechanisms leading to a fuel cell performance and durability under various material conditions. (author)

  14. Studying the effect of material parameters on cell performance of tubular-shaped PEM fuel cell

    A full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena in a PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, transport and phase change mechanism of water, and potential fields. The model is shown to be able to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. In addition to the new feature of tubular-shaped geometry of PEM fuel cell, this model is used to study the effects of several material parameters on fuel cell performance. Detailed analyses of the temperature distribution inside the tubular cell under various material properties have been conducted and examined. The analysis helped identifying critical parameters and shed insight into the physical mechanisms leading to a fuel cell performance and durability under various material conditions

  15. Genetics Home Reference: tubular aggregate myopathy

    ... M, Laporte J. Constitutive activation of the calcium sensor STIM1 causes tubular-aggregate myopathy. Am J Hum ... personal health condition should consult with a qualified healthcare professional . About Genetics Home Reference Site Map Contact ...

  16. Iatrogenic Digital Compromise with Tubular Dressings

    Corre, Kenneth A

    2009-08-01

    Full Text Available Objective: This case report describes a digit amputation resulting from an improperly applied tubular dressing. The safe application of digital tubular dressings, and the rationale behind it, is detailed to raise emergency physician (EP awareness.Methods: We present a case report of a recent iatrogenic-induced digit ischemia caused by improperly applied tube gauze. We review the literature on the subject and the likely sources of poor outcomes presented. The proper application of tubular gauze dressings is then outlined.Conclusion: EPs and emergency department personnel must be educated on the safe application of tubular gauze dressings to avoid dire outcomes associated with improper applications.[WestJEM. 2009;10:190-192.

  17. Thermal CFD Analysis of Tubular Light Guides

    Ondřej Šikula; Jitka Mohelníková; Josef Plášek

    2013-01-01

    Tubular light guides are applicable for daylighting of windowless areas in buildings. Despite their many positive indoor climate aspects they can also present some problems with heat losses and condensation. A computer CFD model focused on the evaluation of temperature distribution and air flow inside tubular light guides of different dimensions was studied. The physical model of the tested light guides of lengths more than 0.60 m proves shows that Rayleigh numbers are adequate for a turbulen...

  18. 78 FR 37584 - U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United...

    2013-06-21

    ... Employment and Training Administration U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United States Steel Corporation, Mckeesport, Pennsylvania; Notice of Amended... workers of U.S. Steel Tubular Products, McKeesport Tubular Operations Division, a subsidiary of...

  19. CD36 mediates proximal tubular binding and uptake of albumin and is upregulated in proteinuric nephropathies.

    Baines, Richard J; Chana, Ravinder S; Hall, Matthew; Febbraio, Maria; Kennedy, David; Brunskill, Nigel J

    2012-10-01

    Dysregulation of renal tubular protein handling in proteinuria contributes to the development of chronic kidney disease. We investigated the role of CD36 as a novel candidate mediator of albumin binding and endocytosis in the kidney proximal tubule using both in vitro and in vivo approaches, and in nephrotic patient renal biopsy samples. In CD36-transfected opossum kidney proximal tubular cells, both binding and uptake of albumin were substantially enhanced. A specific CD36 inhibitor abrogated this effect, but receptor-associated protein, which blocks megalin-mediated endocytosis of albumin, did not. Mouse proximal tubular cells expressed CD36 and this was absent in CD36 null animals, whereas expression of megalin was equal in these animals. Compared with wild-type mice, CD36 null mice demonstrated a significantly increased urinary protein-to-creatinine ratio and albumin-to-creatinine ratio. Proximal tubular cells expressed increased CD36 when exposed to elevated albumin concentrations in culture medium. Expression of CD36 was studied in renal biopsy tissue obtained from adult patients with heavy proteinuria due to minimal change disease, membranous nephropathy, or focal segmental glomerulosclerosis. Proximal tubular CD36 expression was markedly increased in proteinuric individuals. We conclude that CD36 is a novel mediator influencing binding and uptake of albumin in the proximal tubule that is upregulated in proteinuric renal diseases. CD36 may represent a potential therapeutic target in proteinuric nephropathy. PMID:22791331

  20. Osteoprotegerin in exosome-like vesicles from human cultured tubular cells and urine.

    Alberto Benito-Martin

    Full Text Available Urinary exosomes have been proposed as potential diagnostic tools. TNF superfamily cytokines and receptors may be present in exosomes and are expressed by proximal tubular cells. We have now studied the expression of selected TNF superfamily proteins in exosome-like vesicles from cultured human proximal tubular cells and human urine and have identified additional proteins in these vesicles by LC-MS/MS proteomics. Human proximal tubular cells constitutively released exosome-like vesicles that did not contain the TNF superfamily cytokines TRAIL or TWEAK. However, exosome-like vesicles contained osteoprotegerin (OPG, a TNF receptor superfamily protein, as assessed by Western blot, ELISA or selected reaction monitoring by nLC-(QQQMS/MS. Twenty-one additional proteins were identified in tubular cell exosome-like vesicles, including one (vitamin D binding protein that had not been previously reported in exosome-like vesicles. Twelve were extracellular matrix proteins, including the basement membrane proteins type IV collagen, nidogen-1, agrin and fibulin-1. Urine from chronic kidney disease patients contained a higher amount of exosomal protein and exosomal OPG than urine from healthy volunteers. Specifically OPG was increased in autosomal dominant polycystic kidney disease urinary exosome-like vesicles and expressed by cystic epithelium in vivo. In conclusion, OPG is present in exosome-like vesicles secreted by proximal tubular epithelial cells and isolated from Chronic Kidney Disease urine.

  1. Three-dimensional nanotube electrode arrays for hierarchical tubular structured high-performance pseudocapacitors

    Gao, Yuan; Lin, Yuanjing; Chen, Jiaqi; Lin, Qingfeng; Wu, Yue; Su, Wenjun; Wang, Wenli; Fan, Zhiyong

    2016-07-01

    Ordered three-dimensional (3-D) tubular arrays are highly attractive candidates for high performance pseudocapacitor electrodes. Here, we report 3-D fluorine doped tin oxide (FTO) tubular arrays fabricated by a cost-effective ultrasonic spray pyrolysis (USP) method in anodic aluminum oxide (AAO) channels with high uniformity. The large surface area of such a structure leads to remarkable surface area enhancement up to 51.8 times compared to a planar structure. Combining with electrochemically deposited manganese dioxide (MnO2) nanoflakes on the inner side wall of the FTO nanotubes, the unique hierarchical tubular structured pseudocapacitor electrode demonstrated the highest areal capacitance of 193.8 mF cm-2 at the scan rate of 5 mV s-1 and 184 mF cm-2 at the discharge current density of 0.6 mA cm-2, which is 18.5 times that of a planar electrode. And it also showed a volumetric capacitance of 112.6 F cm-3 at the scan rate of 5 mV s-1 and 108.8 F cm-3 at the discharge current density of 0.6 mA cm-2. In addition, the cyclic stability test also indicated that a nanostructured pseudocapacitive electrode has a much larger capacitance retention after 3000 cycles of the charge-discharge process compared with a planar electrode, primarily due to the mechanical stability of the nanostructure. Moreover, pseudocapacitor device fabrication based on such electrodes shows the volumetric capacitance of 17.5 F cm-3, and the highest specific energy of 1.56 × 10-3 Wh cm-3. With the merit of facile fabrication procedures and largely enhanced electrochemical performance, such a 3-D structure has high potency for energy storage systems for a wide range of practical applications.Ordered three-dimensional (3-D) tubular arrays are highly attractive candidates for high performance pseudocapacitor electrodes. Here, we report 3-D fluorine doped tin oxide (FTO) tubular arrays fabricated by a cost-effective ultrasonic spray pyrolysis (USP) method in anodic aluminum oxide (AAO) channels with

  2. Thermal CFD Analysis of Tubular Light Guides

    Ondřej Šikula

    2013-12-01

    Full Text Available Tubular light guides are applicable for daylighting of windowless areas in buildings. Despite their many positive indoor climate aspects they can also present some problems with heat losses and condensation. A computer CFD model focused on the evaluation of temperature distribution and air flow inside tubular light guides of different dimensions was studied. The physical model of the tested light guides of lengths more than 0.60 m proves shows that Rayleigh numbers are adequate for a turbulent air flow. The turbulent model was applied despite the small heat flux differences between the turbulent and laminar model. The CFD simulations resulted into conclusions that the growing ratio of length/diameter increases the heat transmission loss/linear transmittance as much as by 50 percent. Tubular light guides of smaller diameters have lower heat transmission losses compared to the wider ones of the same lengths with the same outdoor temperature being taken into account. The simulation results confirmed the thermal bridge effect of the tubular light guide tube inside the insulated flat roof details. The thermal transmittance of the studied light guides in the whole roof area was substituted with the point thermal bridges. This substitution gives possibility for simple thermal evaluation of the tubular light pipes in roof constructions.

  3. How bio-filaments twist membranes.

    Fierling, Julien; Johner, Albert; Kulić, Igor M; Mohrbach, Hervé; Müller, Martin Michael

    2016-06-29

    We study the deformations of a fluid membrane imposed by adhering stiff bio-filaments due to the torques they apply. In the limit of small deformations, we derive a general expression for the energy and the deformation field of the membrane. This expression is specialised to different important cases including closed and helical bio-filaments. In particular, we analyse interface-mediated interactions and membrane wrapping when the filaments apply a local torque distribution on a tubular membrane. PMID:27291854

  4. Concurrent feline immune-complex nephritis. Tubular antigen-positive and renal amyloidosis.

    Saegusa, S; Shimizu, F; Nagase, M; Kasegawa, A

    1979-08-01

    We describe tubular antigen-positive immune-complex nephritis in a case of feline renal amyloidosis. Amyloid deposition was observed in mesangial area, and thickening of capillary walls was shown in the majority of the glomeruli. This case was also characterized with typical fluorescent granular depositions of cat IgG and C3 along the glomerular capillary walls as seen in human membranous glomerulonephritis. The fluorescent pattern of tubular antigen was identical with that of IgG and C3. Electron micrograph showed the thickening and irregularity of glomerular basement membranes, fusion of foot processes, and deposits of electron-dense or sometimes translucent materials, mostly in the intramembranous location. The causal sequence of the coincidental deposition of amyloid and immune complexes is discussed. PMID:157110

  5. Proximal tubular injury in Chinese herbs nephropathy: monitoring by neutral endopeptidase enzymuria

    Nortier, Joëlle; Deschodt Lanckman, Monique; Simon, Stéphane; Thielemans, N.-O.; De Prez, Eric; Depierreux, Michel; Tielemans, Christian; Richard-Mendes da Costa, C.; Lauwerijs, R.; Bernard, Alfred; Vanherweghem, Jean-Louis

    1997-01-01

    Neutral endopeptidase (NEP) is a 94 kDa ectoenzyme of the proximal tubule brush border, physiologically released into the urine with apical membrane fragments. As proximal tubular atrophy was a histological hallmark of Chinese herbs nephropathy (CHN), this study firstly determined renal excretion of NEP in healthy control subjects (N = 31), in patients with CHN (N = 26) and in women having consumed Chinese herbs and whose renal function was normal but running the risk of developing CHN (N = 2...

  6. Tubular solid oxide fuel cell current collector

    Bischoff, Brian L.; Sutton, Theodore G.; Armstrong, Timothy R.

    2010-07-20

    An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

  7. Fabrication of Pd Micro-Membrane Supported on Nano-Porous Anodized Aluminum Oxide for Hydrogen Separation.

    Kim, Taegyu

    2015-08-01

    In the present study, nano-porous anodized aluminum oxide (AAO) was used as a support of the Pd membrane. The AAO fabrication process consists of an electrochemical polishing, first/second anodizing, barrier layer dissolving and pores widening. The Pd membrane was deposited on the AAO support using an electroless plating with ethylenediaminetetraacetic acid (EDTA) as a plating agent. The AAO had the regular pore structure with the maximum pore diameter of ~100 nm so it had a large opening area but a small free standing area. The 2 µm-thick Pd layer was obtained by the electroless plating for 3 hours. The Pd layer thickness increased with increasing the plating time. However, the thickness was limited to ~5 µm in maximum. The H2 permeation flux was 0.454 mol/m2-s when the pressure difference of 66.36 kPa0.5 was applied at the Pd membrane under 400 °C. PMID:26369167

  8. Failure Modes of thin supported Membranes

    Hendriksen, Peter Vang; Høgsberg, J.R.; Kjeldsen, Ane Mette; Sørensen, Bent F.; Pedersen, H.G.

    Four different failure modes relevant to tubular supported membranes (thin dense films on a thick porous support) were analyzed. The failure modes were: 1) Structural collapse due to external pressure 2) burst of locally unsupported areas, 3) formation of surface cracks in the membrane due to TEC...

  9. Micro/nano-hybrid lens for enhancing light extraction using micro-milling and anodic aluminium oxide (AAO)

    In the recent past there has been much research towards increasing the transmission of light in optical systems by reducing the Fresnel reflection of radiation, as the reflection of light from surfaces seriously decreases the performance of an optical device. These drawbacks have been overcome by mainly two methods, which are anti-reflective coating and anti-reflective nanostructure formation. In this study, we developed a simple fabrication process for Al micro/nano hybrid lens (MNHL) moulds for efficient light extraction using micro-milling and anodic aluminum oxide (AAO). From these moulds, two different types of polymer MNHL were fabricated using hot-embossing; one was a polymer MNHL that was covered with nanostructures over the entire surface, and the other was one for which only the microlens surface was covered with nanostructures. Two different types of polymer MNHLs were evaluated and compared with each other concerning the light extraction performance. The MNHL with nanostructures only on the microlens surface exhibited a higher light extraction performance than the other by 20.7%. It is expected that the fabricated MNHL can be used for the amplification of small signals when observing the presence of bio-molecules dyed with a fluorescent material. (paper)

  10. Micro/nano-hybrid lens for enhancing light extraction using micro-milling and anodic aluminium oxide (AAO)

    Kim, Shin Hyeong; Kim, Min Gu; Kang, Jeong Jin; Lee, Pyeong An; Kim, Bo Hyun; Cho, Young Hak

    2016-01-01

    In the recent past there has been much research towards increasing the transmission of light in optical systems by reducing the Fresnel reflection of radiation, as the reflection of light from surfaces seriously decreases the performance of an optical device. These drawbacks have been overcome by mainly two methods, which are anti-reflective coating and anti-reflective nanostructure formation. In this study, we developed a simple fabrication process for Al micro/nano hybrid lens (MNHL) moulds for efficient light extraction using micro-milling and anodic aluminum oxide (AAO). From these moulds, two different types of polymer MNHL were fabricated using hot-embossing; one was a polymer MNHL that was covered with nanostructures over the entire surface, and the other was one for which only the microlens surface was covered with nanostructures. Two different types of polymer MNHLs were evaluated and compared with each other concerning the light extraction performance. The MNHL with nanostructures only on the microlens surface exhibited a higher light extraction performance than the other by 20.7%. It is expected that the fabricated MNHL can be used for the amplification of small signals when observing the presence of bio-molecules dyed with a fluorescent material.

  11. Trends and ENSO/AAO Driven Variability in NDVI Derived Productivity and Phenology alongside the Andes Mountains

    Francisco J. Meza

    2013-03-01

    Full Text Available Increasing water use and droughts, along with climate variability and land use change, have seriously altered vegetation growth patterns and ecosystem response in several regions alongside the Andes Mountains. Thirty years of the new generation biweekly normalized difference vegetation index (NDVI3g time series data show significant land cover specific trends and variability in annual productivity and land surface phenological response. Productivity is represented by the growing season mean NDVI values (July to June. Arid and semi-arid and sub humid vegetation types (Atacama desert, Chaco and Patagonia across Argentina, northern Chile, northwest Uruguay and southeast Bolivia show negative trends in productivity, while some temperate forest and agricultural areas in Chile and sub humid and humid areas in Brazil, Bolivia and Peru show positive trends in productivity. The start (SOS and length (LOS of the growing season results show large variability and regional hot spots where later SOS often coincides with reduced productivity. A longer growing season is generally found for some locations in the south of Chile (sub-antarctic forest and Argentina (Patagonia steppe, while central Argentina (Pampa-mixed grasslands and agriculture has a shorter LOS. Some of the areas have significant shifts in SOS and LOS of one to several months. The seasonal Multivariate ENSO Indicator (MEI and the Antarctic Oscillation (AAO index have a significant impact on vegetation productivity and phenology in southeastern and northeastern Argentina (Patagonia and Pampa, central and southern Chile (mixed shrubland, temperate and sub-antarctic forest, and Paraguay (Chaco.

  12. SEM and XPS studies of nanohole arrays on InP(1 0 0) surfaces created by coupling AAO templates and low energy Ar + ion sputtering

    Robert-Goumet, C.; Monier, G.; Zefack, B.; Chelda, S.; Bideux, L.; Gruzza, B.; Awitor, O. K.

    2009-10-01

    The aim of the present study is to demonstrate the feasibility to form well-ordered nanoholes on InP(1 0 0) surfaces by low Ar + ion sputtering process in UHV conditions from anodized aluminum oxide (AAO) templates. This process is a promising approach in creating ordered arrays of surface nanostructures with controllable size and morphology. To follow the Ar + ion sputtering effects on the AAO/InP surfaces, X-ray photoelectron spectroscopy (XPS) was used to determine the different surface species. In 4d and P 2p core level spectra were recorded on different InP(1 0 0) surfaces after ions bombardment. XPS results showed the presence of metallic indium on both smooth InP(1 0 0) and AAO/InP(1 0 0) surfaces. Finally, we showed that this experiment led to the formation of metallic In dropplets about 10 nm in diameter on nanoholes patterned InP surface while the as-received InP(1 0 0) surface generated metallic In about 60 nm in diameter.

  13. Effect of various de-anodizing techniques on the surface stability of non-colored and colored nanoporous AAO films in acidic solution

    Awad, Ahmed M.; Shehata, Omnia S.; Heakal, Fakiha El-Taib

    2015-12-01

    Anodic aluminum oxide (AAO) is well known as an important nanostructured material, and a useful template in the fabrication of nanostructures. Nanoporous anodic alumina (PAA) with high open porosity was prepared by adopting three de-anodizing regimes following the first anodizing step and preceding the second one. The de-anodizing methods include electrolytic etching (EE) and chemical etching using either phosphoric acid (PE) or sodium hydroxide (HE) solutions. Three of the obtained AAO samples were black colored by electrodeposition of copper nanoparticles in their pores. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were used to characterize the electrochemical performance of the two sets of the prepared samples. In general, the data obtained in aggressive aerated 0.5 M HCl solution demonstrated dissimilar behavior for the three prepared samples despite that the second anodizing step was the same for all of them. The data indicated that the resistance and thickness of the inner barrier part of nano-PAA film, are the main controlling factors determining its stability. On the other hand, coloring the film decreased its stability due to the galvanic effect. The difference in the electrochemical behavior of the three colored samples was discussed based on the difference in both the pore size and thickness of the outer porous part of PAA film as supported by SEM, TEM and cross-sectional micrographs. These results can thus contribute for better engineering applications of nanoporous AAO.

  14. Work tool in a tubular element

    The stand, which is positioned in relation with the tubular element, has clutch disengagement means for a working rod in rotation, with at least two positioning regions on the rod. Application for laser welding a sleeve into PWR steam generator tubes

  15. [Hypokalemic pareses secondary to renal tubular acidosis].

    Gøransson, L G; Apeland, T; Omdal, R

    2000-01-30

    A 24 year old woman presented with flaccid paralysis, severe hypokalaemia and hyperchloremia, metabolic acidosis. Immunological tests and labial glandular biopsy indicated primary Sjögren's syndrome as the underlying cause of her distal renal tubular acidosis. The patient recovered after alkali and potassium substitution and was put on oral treatment with potassium citrate. PMID:10827521

  16. Tubular spring slip joint and jar

    The present invention comprises a pressure balanced tubular spring slip-joint and jar including a generally tubular outer housing having longitudinal slot means in the wall thereof, and a hammer area of increased wall thickness at one end thereof, within which housing slidably extends a jar mandrel means having first and second longitudinally spaced enlarged diameter anvil areas, at least one fastener tapped into one of those anvil areas, the heads of said fastener protruding into said slot means. Both said housing and said mandrel means possesses axial bores therethrough, which are placed in communication via the bore of a tubular spring within the housing, whereby during extension and contraction of the slip-joint and jar means of the present invention the area within said axial bores and said spring bore is of a constant volume. The invention may be employed to provide force impulses in either longitudinal direction, said tubular spring aiding the application of those impulses when said housing and said mandrel means move relatively toward each other. By proper selection of spring length and use of a coiled spring having spaced coils, the present invention may also be employed as a bi-directional shock absorber

  17. Tubular spring slip joint and jar

    Heemstra, T. R.

    1985-04-23

    The present invention comprises a pressure balanced tubular spring slip-joint and jar including a generally tubular outer housing having longitudinal slot means in the wall thereof, and a hammer area of increased wall thickness at one end thereof, within which housing slidably extends a jar mandrel means having first and second longitudinally spaced enlarged diameter anvil areas, at least one fastener tapped into one of those anvil areas, the heads of said fastener protruding into said slot means. Both said housing and said mandrel means possesses axial bores therethrough, which are placed in communication via the bore of a tubular spring within the housing, whereby during extension and contraction of the slip-joint and jar means of the present invention the area within said axial bores and said spring bore is of a constant volume. The invention may be employed to provide force impulses in either longitudinal direction, said tubular spring aiding the application of those impulses when said housing and said mandrel means move relatively toward each other. By proper selection of spring length and use of a coiled spring having spaced coils, the present invention may also be employed as a bi-directional shock absorber.

  18. Vibration analysis of ultrasonic tubular resonators

    LIANG Zhaofeng; MO Xiping; ZHOU Guangping

    2012-01-01

    The frequency equation of the axisymmetric coupled vibration of a ultrasonic tubular resonator with both ends free is derived by an exact solution method, based on classical Fliigge thin shell theory. The dependence of the dimensionless frequency Ω on the ratio of length to radius 1/a, the ratio of radius to thickness a/h and Poisson's ratio v is investigated, and the axisymmetric coupled vibration of the ultrasonic tubular resonator with both ends shear diaphragm is compared with that with both ends free. The accuracy of two-dimensional and three-dimensional apparent elasticity method is also assessed by the comparison with the exact solution method. Finally, the mode shapes of the ultrasonic tubular resonator are calculated by the exact solution method, and its transform efficient is analyzed. The results show that as for two boundary conditions of both ends free and both ends shear diaphragm, the difference of the effect of the boundary conditions on the dimensionless frequency of the axisymmetric coupled vibration of the ultrasonic tubular resonator becomes smaller as l/a increases, and the larger a/h, the smaller the difference. Moreover, for free-free boundary conditions, the change of a/h has nearly no effect on the dimensionless frequency of the thin tubular resonator usually considered to mean a/h 〉 10. Purthermore, the dimensionless frequency Ω decreases as v in- creases for a given l/a, and the impact of v on Ω is different for different l/a, and the maximum impact will appear when l/a = π. Finally, the study also shows the three-dimensional apparent elasticity method has very high accuracy.

  19. 78 FR 14361 - U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United...

    2013-03-05

    ... Employment and Training Administration U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United States Steel Corporation, Mckeesport, PA; Notice of Initiation of...) filed on December 20, 2012 on behalf of workers of U.S. Steel Tubular Products, McKeesport...

  20. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge

  1. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    Huang, Manhong, E-mail: egghmh@163.com; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-11-15

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge.

  2. Distal renal tubular acidosis in recurrent renal stone formers

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available, this...... (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...

  3. Renal tubular acidosis complicated with hypokalemic periodic paralysis.

    Chang, Y C; Huang, C C; Chiou, Y Y; Yu, C Y

    1995-07-01

    Three Chinese girls with hypokalemic periodic paralysis secondary to different types of renal tubular acidosis are presented. One girl has primary distal renal tubular acidosis complicated with nephrocalcinosis. Another has primary Sjögren syndrome with distal renal tubular acidosis, which occurs rarely with hypokalemic periodic paralysis in children. The third has an isolated proximal renal tubular acidosis complicated with multiple organ abnormalities, unilateral carotid artery stenosis, respiratory failure, and consciousness disturbance. The diagnostic evaluation and emergent and prophylactic treatment for these three types of renal tubular acidosis are discussed. PMID:7575850

  4. Solar driven membrane pervaporation for desalination processes

    Zwijnenberg, H.J.; Koops, G.H.; Wessling, M.

    2005-01-01

    We describe details of a solar driven pervaporation process for the production of desalinated water from highly contaminated waters. The membrane material is a polyetheramide-based polymer film of 40 ¿m thickness. This Solar Dew® membrane is used in a tubular configuration in a direct solar membrane pervaporation process. The feed waters used in this study are untreated seawater and waste water that is simultaneously produced with the mineral oil extraction. In all cases retention of typical ...

  5. The swan-neck lesion: proximal tubular adaptation to oxidative stress in nephropathic cystinosis.

    Galarreta, Carolina I; Forbes, Michael S; Thornhill, Barbara A; Antignac, Corinne; Gubler, Marie-Claire; Nevo, Nathalie; Murphy, Michael P; Chevalier, Robert L

    2015-05-15

    Cystinosis is an inherited disorder resulting from a mutation in the CTNS gene, causing progressive proximal tubular cell flattening, the so-called swan-neck lesion (SNL), and eventual renal failure. To determine the role of oxidative stress in cystinosis, histologic sections of kidneys from C57BL/6 Ctns(-/-) and wild-type mice were examined by immunohistochemistry and morphometry from 1 wk to 20 mo of age. Additional mice were treated from 1 to 6 mo with vehicle or mitoquinone (MitoQ), an antioxidant targeted to mitochondria. The leading edge of the SNL lost mitochondria and superoxide production, and became surrounded by a thickened tubular basement membrane. Progression of the SNL as determined by staining with lectin from Lotus tetragonolobus accelerated after 3 mo, but was delayed by treatment with MitoQ (38 ± 4% vs. 28 ± 1%, P injury molecule-1 (KIM-1) nor cell death was observed. After 9 mo, clusters of proximal tubules exhibited localized oxidative stress (4-hydroxynonenal binding), expressed KIM-1, and underwent apoptosis, leading to the formation of atubular glomeruli and accumulation of interstitial collagen. We conclude that nephron integrity is initially maintained in the Ctns(-/-) mouse by adaptive flattening of cells of the SNL through loss of mitochondria, upregulation of transgelin, and thickened basement membrane. This adaptation ultimately fails in adulthood, with proximal tubular disruption, formation of atubular glomeruli, and renal failure. Antioxidant treatment targeted to mitochondria delays initiation of the SNL, and may provide therapeutic benefit in children with cystinosis. PMID:25694483

  6. Tubular Heart Pumping Mechanisms in Ciona Intestinalis

    Battista, Nicholas; Miller, Laura

    2015-11-01

    In vertebrate embryogenesis, the first organ to form is the heart, beginning as a primitive heart tube. However, many invertebrates have tubular hearts from infancy through adulthood. Heart tubes have been described as peristaltic and impedance pumps. Impedance pumping assumes a single actuation point of contraction, while traditional peristalsis assumes a traveling wave of actuation. In addition to differences in flow, this inherently implies differences in the conduction system. It is possible to transition from pumping mechanism to the other with a change in the diffusivity of the action potential. In this work we consider the coupling between the fluid dynamics and electrophysiology of both mechanisms, within a basal chordate, the tunicate. Using CFD with a neuro-mechanical model of tubular pumping, we discuss implications of the both mechanisms. Furthermore, we discuss the implications of the pumping mechanism on evolution and development.

  7. Glomerular tubular balance: mediation by luminal hypotonicity.

    Häberle, D A; Müller, U; Nagel, W

    1989-01-01

    Late proximal rat tubular segments were microperfused with slightly hypo- or hypertonic artificial late proximal tubular fluid (ATF) at low (11-13 nl/min) or high (30-38 nl/min) perfusion rates. Volume reabsorption, net chloride and solute reabsorption were measured as a function of length. In addition, the transepithelial resistance and voltage (Vte) were measured as a function of the applied osmotic gradient. Hypertonic solutions equilibrated to isotonicity by solute outflow rather than water influx. With hypertonic ATF the lumen positive Vte was decreased compared with free flow or with hypotonic ATF. The resistance was not significantly different between the different groups. In contrast to hypotonic ATF, hypertonic or isotonic ATF was not significantly reabsorbed. In addition, hypotonic ATF maintained its hypotonicity along the perfused segments. Its reabsorption was flow-dependent. Hypotonicity appeared to enhance solute reabsorption. PMID:2725432

  8. Tubular electric heater with a thermocouple assembly

    This patent relates to a thermocouple or other instrumentation which is installed within the walls of a tubular sheath surrounding a process device such as an electric heater. The sheath comprises two concentric tubes, one or both of which have a longitudinal, concave crease facing the other tube. The thermocouple is fixedly positioned within the crease and the outer tube is mechanically reduced to form an interference fit onto the inner tube

  9. Clinical profile of distal renal tubular acidosis

    Ratan Jha; Muthukrishnan, J.; Shekhar Shiradhonkar; Kiran Patro; Harikumar KVS; Modi, K.D.

    2011-01-01

    To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA), we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive ...

  10. Inherited renal tubular defects with hypokalemia

    Muthukrishnan J; Modi K; Kumar P; Jha Ratan

    2009-01-01

    Bartter′s and Gitelman′s syndrome are two ends of a spectrum of inherited renal tubular disorders that present with hypokalemic metabolic alkalosis of varying severity. Clinical features and associated calcium and magnesium ion abnormalities are used to diagnose these cases after excluding other commoner causes. We report on two cases, the first being a young boy, born of pregnancy complicated by polyhydramnios, who had classical dysmorphic features, polyuria, hypokalemia and hy...

  11. Energy production with a tubular propeller turbine

    Almeida Samora, Irene; Hasmatuchi, Vlad; Münch-Alligné, C.; Franca, Mário J.; Schleiss, Anton; Helena M. Ramos

    2016-01-01

    Micro-hydropower is a way of improving the energetic efficiency of existent water systems. In the particular case of drinking water systems, several studies have showed that pressure reducing valves can be by-passed with turbines in order to recover the dissipated hydraulic energy to produce electricity. As conventional turbines are not always cost-effective for power under 20 kW, a new energy converter is studied. A five blade tubular propeller (5BTP), assessed through laboratorial tests on ...

  12. Three-dimensional computational fluid dynamics model of a tubular-shaped PEM fuel cell

    Sadiq Al-Baghdadi, Maher A.R. [Department of Mechanical Engineering, International Technological University, 289 Cricklewood Broadway, London NW2 6NX (United Kingdom)

    2008-06-15

    A full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena in a PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, and potential fields. In addition to the tubular-shaped geometry, the model feature an algorithm that allows for more realistic representation of the local activation overpotentials which leads to improved prediction of the local current density distribution. Three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented. The model is shown to be able to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. (author)

  13. Transmission Characteristics in Tubular Acoustic Metamaterials Studied with Fluid Impedance Theory

    Tubular acoustic metamaterials with negative densities composed of periodical membranes set up along pipes are studied with the fluid impedance theory. In addition to the conventional forbidden bands induced by the Bragg-scattering due to the periodic distributions of different acoustic impedances, the low-frequency forbidden band (LFB) with the low-frequency limit of zero Hertz is studied, in which the LFB is explained with acoustic impedance matching and the Bloch theory. Furthermore, the influences of the structural parameters of the tubular acoustic metamaterials on the transmission characteristics, such as the transmission coefficients, dispersion curves, widths of forbidden and pass bands, fluctuations in pass bands, etc., are evaluated, which can be used in the optimization of the acoustic insulation ability of the metamaterials. (fundamental areas of phenomenology (including applications))

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

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

    2014-01-07

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

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

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

    2016-01-19

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

  16. A simple auxetic tubular structure with tuneable mechanical properties

    Ren, Xin; Shen, Jianhu; Ghaedizadeh, Arash; Tian, Hongqi; Xie, Yi Min

    2016-06-01

    Auxetic materials and structures are increasingly used in various fields because of their unusual properties. Auxetic tubular structures have been fabricated and studied due to their potential to be adopted as oesophageal stents where only tensile auxetic performance is required. However, studies on compressive mechanical properties of auxetic tubular structures are limited in the current literature. In this paper, we developed a simple tubular structure which exhibits auxetic behaviour in both compression and tension. This was achieved by extending a design concept recently proposed by the authors for generating 3D metallic auxetic metamaterials. Both compressive and tensile mechanical properties of the auxetic tubular structure were investigated. It was found that the methodology for generating 3D auxetic metamaterials could be effectively used to create auxetic tubular structures as well. By properly adjusting certain parameters, the mechanical properties of the designed auxetic tubular structure could be easily tuned.

  17. Tailoring of porosity of yttria-stabilized zirconia tubes as supports for oxygen separation membranes

    Bjørnetun Haugen, Astri; Kothanda Ramachandran, Dhavanesan; Gurauskis, Jonas;

    straightforward sealing. The active oxygen separation layer in the membrane should be as thin as possible and therefore supported on a highly porous tubular substrate. In this work tubular porous supports of yttria-stabilized zirconia have been manufactured using thermoplastic extrusion. Two types of poreformers...

  18. Hyaluronan in Tubular and Interstitial Nephrocalcinosis

    Verkoelen, Carl F.

    2007-04-01

    Hyaluronan (HA) is the major glycosaminoglycan (GAG) component of the renal medullary interstitium. HA is extremely large (up to 104 kDa) and composed of thousands repeating disaccharides of glucuronic acid (GlcUA) and N-acetylglucosamine (GlcNAc). HA is synthesized by hyaluronan synthases (HASs) and degraded by hyaluronidases (Hyals). The production of HA by renomedullary interstitial cells is mediated by local osmolality. When excess water needs to be excreted, increased interstitial HA seems to antagonize water reabsorption, while the opposite occurs during water conservation. Hence, papillary interstitial HA is low and Hyal high during anti-diuresis, whereas during diuresis HA is high and Hyal low. The polyanion HA plays a role in the reabsorption of hypotonic fluid by immobilizing cations (Na+) via the carboxylate (COO-) groups of GlcUA. The binding of Ca2+ to anionic HA is probably also responsible for the fact that the papilla does not become a stone despite the extremely high interstitial phosphate and oxalate. HA is also an excellent crystal binding molecule. The expression of HA at the luminal surface of renal tubular cells leads to tubular nephrocalcinosis (tubular NC). Calcium staining methods (Von Kossa, Yasue) demonstrated that crystallization inhibitors cannot avoid the occasional precipitation of calcium phosphate in the papillary interstitium (interstitial NC). These crystals are probably immediately immobilized by the gel-like HA matrix. After ulcerating through the pelvic wall the calcified matrix becomes a Randall's plaque. The attachment of calcium oxalate crystals from the primary urine to plaque may ultimately lead to the development of clinical stones in the renal calyces (nephrolithiasis).

  19. Carbon Tubular Morphologies in Blast Furnace Coke

    Stanislav S. Gornostayev; Jouko J. Härkki

    2008-01-01

    The paper reports on the first occurrence of microscale carbon tubular morphologies (CMTs) in a blast furnace (BF) coke. The CMTs were probably formed as a result of the conversion of solid disordered carbon via liquid phase metal particles involving a gas phase containing a substantial amount of N 2 and O 2 . The presence of CMTs may lie behind the generation of the smallest fraction of fines in BF exhaust dust. If the amount of CMTs present in the BF exhausts gases at any particular metallu...

  20. Carbon Tubular Morphologies in Blast Furnace Coke

    Stanislav S. Gornostayev

    2008-01-01

    Full Text Available The paper reports on the first occurrence of microscale carbon tubular morphologies (CMTs in a blast furnace (BF coke. The CMTs were probably formed as a result of the conversion of solid disordered carbon via liquid phase metal particles involving a gas phase containing a substantial amount of N2 and O2. The presence of CMTs may lie behind the generation of the smallest fraction of fines in BF exhaust dust. If the amount of CMTs present in the BF exhausts gases at any particular metallurgical site proves to be substantial, it could become a subject of environmental concern.

  1. TUBULAR PHOTOBIOREACTOR FOR MICROALGAE BIODIESEL PRODUCTION

    Nkongolo Mulumba; Ihab H. Farag

    2012-01-01

    Biodiesel production from algae is a promising technique. Microalgae have the potential to produce 5,000-15,000 gallons of biodiesel/(acre-year). However, there are challenges; these include high yieldof algae biomass with high lipid content and the effective technique to harvest the grown algae, extract the algal oil and transesterify the oil to biodiesel. In this project Tubular PhotoBioReactor (TPBR) was designed and achieved a ten times increase in algae concentration. It produced 1g of d...

  2. Tubular solid oxide fuel cell development program

    NONE

    1995-08-01

    This paper presents an overview of the Westinghouse Solid Oxide Fuel Cell (SOFC) development activities and current program status. The Westinghouse goal is to develop a cost effective cell that can operate for 50,000 to 100,000 hours. Progress toward this goal will be discussed and test results presented for multiple single cell tests which have now successfully exceeded 56,000 hours of continuous power operation at temperature. Results of development efforts to reduce cost and increase power output of tubular SOFCs are described.

  3. Distal Renal Tubular Acidosis and Calcium Nephrolithiasis

    Moe, Orson W.; Fuster, Daniel G.; Xie, Xiao-Song

    2008-09-01

    Calcium stones are commonly encountered in patients with congenital distal renal tubular acidosis, a disease of renal acidification caused by mutations in either the vacuolar H+-ATPase (B1 or a4 subunit), anion exchanger-1, or carbonic anhydrase II. Based on the existing database, we present two hypotheses. First, heterozygotes with mutations in B1 subunit of H+-ATPase are not normal but may harbor biochemical abnormalities such as renal acidification defects, hypercalciuria, and hypocitraturia which can predispose them to kidney stone formation. Second, we propose at least two mechanisms by which mutant B1 subunit can impair H+-ATPase: defective pump assembly and defective pump activity.

  4. Strength of Concrete Filled Steel Tubular Columns

    Muhammad Naseem Baig; FAN Jiansheng; NIE Jianguo

    2006-01-01

    Composite columns of steel and concrete have been used and studied world wide, but filled tubular columns need more attention. This paper presents an experimental study on the behavior of short concrete filled steel tubular columns (CFT) axially loaded in compression to failure. A total of 28 specimens (16 were filled with concrete and 12 were kept hollow) with different cross-sections were tested to investigate the load capacity. The length-to-diameter ratios of these columns were between 4 and 9. Parameters for the tests were tube shape and diameter-to-thickness ratio. Some of the concrete filled columns had internal bracing of #3 deformed bars. The test results are compared with the theoretical results and previous studies. The results show that the confinement effect on concrete does play a role in increasing the compressive strengths to almost 60% in some cases. Based on the test results, an equation to estimate the ultimate axial compressive loading capacities is also proposed for square CFT columns.

  5. Early segmental changes in ischemic acute tubular necrosis of the rat kidney

    Faarup, Poul; Nørgaard, Tove; Hegedüs, Viktor; Holstein-Rathlou, N.-H.

    2004-01-01

    subsequent freeze-substitution in alcohol. The microscopic slides from the kidneys were silver methenamine-PAS stained. In the segments of the proximal convoluted tubules of the nephrons, presence of nuclear pyknosis, places of denuded basement membranes and presence of exfoliated tubular cells were counted...... tubule versus the subsequent loops. The distribution of the structural lesions is in accordance with the previously reported presence of a tubulo-capillary counter-current flow in the proximal convoluted tubule and, when related to the highly variable oxygen tension in the normal renal cortex of the rat...

  6. Overendocytosis of gold nanoparticles increases autophagy and apoptosis in hypoxic human renal proximal tubular cells

    Ding F

    2014-09-01

    production of reactive oxygen species, the loss of mitochondrial membrane potential (ΔΨM, and an increase in apoptosis and autophagic cell death. Conclusion/significance: Our results demonstrate that renal tubular epithelial cells presented different responses under normoxic and hypoxic environments, which provide an important basis for understanding the risks associated with GNP use–especially for the potential GNP-related therapies in chronic kidney disease patients. Keywords: gold nanoparticles (GNPs, toxicity, autophagy, apoptosis 

  7. Preparation and gas separation properties of zeolite T membrane.

    Cui, Ying; Kita, Hidetoshi; Okamoto, Ken-ichi

    2003-09-01

    Zeolite T membranes were synthesized on tubular porous mullite tubes by hydrothermal synthesis. The membranes selectively permeated carbon dioxide from CO2/CH4 and CO2/N2 mixtures with high separation performances, which were due to combined effects of molecular sieving and competitive adsorption. PMID:13678177

  8. Preparation and gas separation properties of zeolite T membrane

    Ying Cui; Hidetoshi Kita; Ken-ichi Okamoto [Yamaguchi University (Japan)

    2003-07-01

    Zeolite T membranes were synthesized on tubular porous mullite tubes by hydrothermal synthesis. The membranes selectively permeated carbon dioxide from CO{sub 2}/CH{sub 4} and CO{sub 2}/N{sub 2} mixtures with high separation performances, which were due to combined effects of molecular sieving and competitive adsorption.

  9. Type IV renal tubular acidosis associated with Alport's syndrome.

    Tkácová, R.; Roland, R.; Böör, A.; Kovácová, A.; Lazúrová, I.; Tkác, I.; Hildebrand, T.; Sefara, P.

    1993-01-01

    A case of hereditary nephritis with mild reduction of renal function associated with renal tubular acidosis type IV is described. The patient was admitted with life-threatening hyperkalaemia. To our knowledge, type IV renal tubular acidosis has not been reported previously in association with Alport's syndrome in an adult patient.

  10. Theoretical and experimental investigations of Chinese evacuated tubular solar collectors

    Qin, Lin; Furbo, Simon

    1999-01-01

    Four different marketed Chinese evacuated tubular solar collectors have been investigated both theoretically and experimentally. The advantages of the investigated solar collectors compared to normal flat plate collectors were elucidated.......Four different marketed Chinese evacuated tubular solar collectors have been investigated both theoretically and experimentally. The advantages of the investigated solar collectors compared to normal flat plate collectors were elucidated....

  11. Renal tubular acidosis due to the milk-alkali syndrome.

    Rochman, J; Better, O S; Winaver, J; Chaimowitz, C; Barzilai, A; Jacobs, R

    1977-06-01

    A 60-year-old man with a history of excessive ingestion of calcium carbonate presented with azotemia, hypercalcemia and hyperphosphatemia. His acid-base status was initially normal. Following the cessation of calcium carbonate treatment, the hypercalcemia and azotemia disappeared, and the patient was found to be in metabolic acidosis with blunted acid excretion and a urine pH of 6.1. Kidney biopsy showed focal tubular calcification; the tubular damage was apparently caused by hypercalcemia and had resulted in renal tubular acidosis. During the three months of observation since that time there has been a tendecy for spontaneous remission of the renal tubular acidosis. Impaired renal hydrogen ion excretion prevented the development of metabolic alkalosis despite ingestion of alkali initially, and was later responsible for the metabolic acidosis. Renal tubular acidosis occurring as a sequel to the milk-alkali syndrome may aggravate the danger of nephrocalcinosis in this syndrome. PMID:885714

  12. Confined semiflexible biopolymers suppress fluctuations of soft membrane tubes

    Abel, Steven; Mirzaeifard, Sina

    Membrane nanotubes are tubular membrane structures that contain actin and connect cells over long distances. Disrupting the actin cytoskeleton abrogates membrane nanotubes, making them an interesting model system for studying membrane-biopolymer interactions. In this study, we use Monte Carlo computer simulations to investigate tubular, elastic membrane structures with and without semiflexible polymers confined inside. At small values of membrane bending rigidity, fluid membranes adopt irregular, highly fluctuating shapes while non-fluid membranes maintain extended tube-like structures. With increasing bending rigidity, fluid membranes exhibit a local maximum in specific heat that is coincident with a transition to extended tube-like structures. We further find that confining a semiflexible polymer within a fluid membrane tube suppresses membrane shape fluctuations and reduces the specific heat of the membrane. Polymers with a sufficiently large persistence length can significantly deform the membrane tube, leading to localized bulges in the membrane that accommodate regions in which the polymer forms loops. Analytical calculations of the energies of idealized polymer-membrane configurations provide additional insight into the formation of polymer-induced membrane deformations.

  13. TUBULAR PHOTOBIOREACTOR FOR MICROALGAE BIODIESEL PRODUCTION

    Nkongolo Mulumba

    2012-02-01

    Full Text Available Biodiesel production from algae is a promising technique. Microalgae have the potential to produce 5,000-15,000 gallons of biodiesel/(acre-year. However, there are challenges; these include high yieldof algae biomass with high lipid content and the effective technique to harvest the grown algae, extract the algal oil and transesterify the oil to biodiesel. In this project Tubular PhotoBioReactor (TPBR was designed and achieved a ten times increase in algae concentration. It produced 1g of dry algal biomass per liter of medium within 12 days, with a lipid content of 12% approximately. Healthy algal culture grew well in the TPBR reaching 56x106 cells/mL of culture medium. The 10 fold increase is higher than those reported for open ponds and helical photobioreactor.

  14. Inherited renal tubular defects with hypokalemia

    Muthukrishnan J

    2009-01-01

    Full Text Available Bartter′s and Gitelman′s syndrome are two ends of a spectrum of inherited renal tubular disorders that present with hypokalemic metabolic alkalosis of varying severity. Clinical features and associated calcium and magnesium ion abnormalities are used to diagnose these cases after excluding other commoner causes. We report on two cases, the first being a young boy, born of pregnancy complicated by polyhydramnios, who had classical dysmorphic features, polyuria, hypokalemia and hypercalciuria and was diagnosed as having Bartter′s syndrome. The second patient is a lady who had recurrent tetany as the only manifestation of Gitelman′s syndrome, which is an unusual presentation. Potassium replacement with supplementation of other deficient ions led to satisfactory clinical and biochemical response.

  15. Cytocompatibility of a silk fibroin tubular scaffold

    Wang, Jiannan, E-mail: wangjn@suda.edu.cn; Wei, Yali; Yi, Honggen; Liu, Zhiwu; Sun, Dan; Zhao, Huanrong

    2014-01-01

    Regenerated silk fibroin (SF) materials are increasingly used for tissue engineering applications. In order to explore the feasibility of a novel biomimetic silk fibroin tubular scaffold (SFTS) crosslinked by poly(ethylene glycol) diglycidyl ether (PEG-DE), biocompatibility with cells was evaluated. The novel biomimetic design of the SFTS consisted of three distinct layers: a regenerated SF intima, a silk braided media and a regenerated SF adventitia. The SFTS exhibited even silk fibroin penetration throughout the braid, forming a porous layered tube with superior mechanical, permeable and cell adhesion properties that are beneficial to vascular regeneration. Cytotoxicity and cell compatibility were tested on L929 cells and human umbilical vein endothelial cells (EA.hy926). DNA content analysis, scanning electron and confocal microscopies and MTT assay showed no inhibitory effects on DNA replication. Cell morphology, viability and proliferation were good for L929 cells, and satisfactory for EA.hy926 cells. Furthermore, the suture retention strength of the SFTS was about 23 N and the Young's modulus was 0.2–0.3 MPa. Collectively, these data demonstrate that PEG-DE crosslinked SFTS possesses the appropriate cytocompatibility and mechanical properties for use as vascular scaffolds as an alternative to vascular autografts. - Highlights: • A PEG-DE cross-linked small caliber porous silk fibroin tubular scaffold (SFTS) • PEG-DE cross-linked SF film had no inhibitory effect on DNA replication of cells. • Cells cultured on the SFTS showed good morphology, cell viability and proliferative activity. • SFTS would be beneficial to endothelialization. • SFTS had good suture retention strength and flexibility.

  16. Size effect of welded thin-walled tubular joints

    Mashiri, Fidelis Rutendo; Zhao, Xiao-Ling; Hirt, Manfred A.; NUSSBAUMER, Alain

    2007-01-01

    This paper clarifies the terminologies used to describe the size effect on fatigue behaviour of welded joints. It summarizes the existing research on size effect in the perspective of newly defined terminologies. It identifies knowledge gaps in designing tubular joints using the hot spot stress method, i.e. thin-walled tubular joints with wall thickness less than 4 mm and thick-walled tubular joints with wall thickness larger than 50 mm or diameter to thickness ratio less than 24. It is the t...

  17. Al膜平整度对硅基AAO有序度的影响%Effect of Flatness of Al Film on Fabrication of AAO Template on Silicon Substrate

    李芹; 张海明; 胡国锋; 高波; 朱彦君; 李菁

    2011-01-01

    Using vacuum electron beam evaporation technology, two kinds of different smoothness of Al films had been prepared through changing the rate of evaporation Al on P-type Si substrate.The A1 films were treated with a one-step anodization process in oxalic acid, and then research findings showed that anodic oxidation film flatness had an effect on A1 silicon-based AAO(anodic aluminum oxide) order degrees. The results showed that the flatness of Al film largely determined the order of silicon-based AAO. The higher the smoothness of silicon-based A1 films is, the better the silicon-based AAO degree of order is obtained. In addition, the results display that the order degree of the silicon-based AAO has been significantly improved by using two-step anodization.%利用真空电子束蒸发技术,通过改变Al的蒸发速率在P型晶向的单晶硅片上制备了两种不同平整度的Al膜,在草酸中对它们分别进行一次阳极氧化,研究Al膜平整度对硅基AAO(多孔硅基氧化铝)有序度的影响.结果表明,硅基AAO的有序度对Al膜的平整度有很大的依赖性,硅基Al膜的平整度越高,所获得的硅基AAO的有序度就越好.另外,对平整度较差的Al膜进行二次阳极氧化可以显著地改善硅基AAO的有序度.

  18. Effect of tamoxifen on spermatogenesis and tubular morphology in rats

    UrbanJ.A.D'Souza

    2004-01-01

    Aim: To observe the effect of tamoxifen citrate on spermatogenesis and tubular morphology in rats.Methods: The effect of tamoxifen citrate i.g. at doses of 400 and 800 mg·kg-1·day-1 in 0.1 mL olive oil for 30 days on seminiferous tubular morphology, seminiferous epithelial diameter (STD), epithelial height (SEH), epididymal sperm count and percent abnormal sperm were evaluated at day 1, 12 and 36 after treatment. Controls were given the vehicle. Results: The higher dose resulted in tubular atrophy on day 31. The STD, SEH and sperm count were decreased and the abnormal spermatozoa increased in a dose-dependent manner with the maximal effect on day 36.Conclusion: Tamoxifen citrate induces tubular shrinkage and atrophy and sperm abnormality at a dose-dependent manner. (Asian J Androl 2004 Sep; 6: 223-226)

  19. Device for internal laser welding of tubular elements

    During the welding, the position of the returning mirror of the laser beam is on the order of a transducer in support on the tubular element to be welded. Application for sleeving PWR steam generator tubes

  20. Atypical presentation of distal renal tubular acidosis in two siblings.

    Tasic, Velibor; Korneti, Petar; Gucev, Zoran; Hoppe, Bernd; Blau, Nenad; Cheong, Hae Il

    2008-07-01

    Primary distal renal tubular acidosis (dRTA) is an inherited disease characterized by the inability of the distal tubule to lower urine pH hypokalemic paralysis. Laboratory investigations revealed proximal tubular dysfunction (low molecular weight proteinuria, generalized hyperaminoaciduria, hypophosphatemia with hyperphosphaturia, and hypouricemia with hyperuricosuria). There was significant hyperoxaluria and laboratory evidence for mild rhabdomyolysis. Under potassium and alkali therapy, proximal tubular abnormalities, muscular enzymes, and oxaluria normalized. A homozygous mutation in the ATP6V1B1 gene, which is responsible for dRTA with early hearing loss, was detected in both siblings. In conclusion, proximal tubular dysfunction and hyperoxaluria may be found in children with dRTA and are reversible under appropriate therapy. PMID:18386070

  1. Solar Heating Systems with Evacuated Tubular Solar Collector

    Qin, Lin; Furbo, Simon

    1998-01-01

    Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

  2. Elastic Deployable Composite Tubular Roll-Out Boom Project

    National Aeronautics and Space Administration — DSS's innovative Elastic Deployable Composite Tubular Roll-Out Boom will provide revolutionary performance when compared to conventional state-of-the-art...

  3. Genetics Home Reference: renal tubular acidosis with deafness

    ... Prevention: Hearing Loss in Children Centre for Genetics Education (Australia): Deafness and Hearing Loss Gallaudet University: Laurent Clerc National Deaf Education Center KidsHealth: What's Hearing Loss? MalaCards: renal tubular ...

  4. A tubular electrode for radiofrequency ablation therapy

    Antunes, Carlos Lemos Lemos Lemos

    2012-07-06

    Purpose – Due to its good mechanical and biocompatibility characteristics, nitinol SEMS is a popular endoprothesis used for relieving stricture problems in hollow organs due to carcinomas. Besides its mechanical application, SEMS can be regarded as well as potential electrode for performing RF ablation therapy on the tumor. The purpose of this work is to perform numerical and experimental analyses in order to characterize the lesion volume induced in biological tissue using this kind of tubular electrode. Design/methodology/approach – Data concerning electrical conductivity and dimension of the damaged tissue after RF ablation procedure were obtained from ex vivo samples. Next, numerical models using 3D finite element method were obtained reassembling the conditions considered at experimentation setup and results were compared. Findings – Numerical and experimental results show that a regular volume of damaged tissue can be obtained considering this type of electrode. Also, results obtained from numerical simulation are close to those obtained by experimentation. Originality/value – SEMSs, commonly used as devices to minimize obstruction problems due to the growth of tumors, may still be considered as an active electrode for RF ablation procedures. A method considering this observation is presented in this paper. Also, numerical simulation can be regarded in this case as a tool for determining the lesion volume.

  5. Clinical profile of distal renal tubular acidosis

    Ratan Jha

    2011-01-01

    Full Text Available To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA, we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive urine anion gap. In those patients who had fasting urine pH >5.5 with normal baseline systemic pH and bicarbonate levels (incomplete RTA, acid load test with ammonium chloride was done. A cause of dRTA could be established in 53 (54% patients. Urological defect in children (22/44 and autoimmune disease in adults (11/52 were the commonest causes. Hypokalemic paralysis, proximal muscle weakness and voiding difficulty were the common modes of presentation. Doubling of serum creatinine during the study period was noted in 13 out of 27 patients who had GFR 60 mL/min (P <0.005. In conclusion, urological disorders were the commonest cause of dRTA in children while autoimmune disorders were the commonest asso-ciation in adults. Worse baseline renal function, longer duration of disease and greater frequency of nephrolithiasis/nephrocalcinosis and urological disorders were noted in those who had wor-sening of renal dysfunction during the study period.

  6. Clinical profile of distal renal tubular acidosis.

    Jha, Ratan; Muthukrishnan, J; Shiradhonkar, Shekhar; Patro, Kiran; Harikumar, Kvs; Modi, K D

    2011-03-01

    To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA), we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive urine anion gap. In those patients who had fasting urine pH >5.5 with normal baseline systemic pH and bicarbonate levels (incomplete RTA), acid load test with ammonium chloride was done. A cause of dRTA could be established in 53 (54%) patients. Urological defect in children (22/44) and autoimmune disease in adults (11/52) were the commonest causes. Hypokalemic paralysis, proximal muscle weakness and voiding difficulty were the common modes of presentation. Doubling of serum creatinine during the study period was noted in 13 out of 27 patients who had GFR 60 mL/min (P <0.005). In conclusion, urological disorders were the commonest cause of dRTA in children while autoimmune disorders were the commonest asso-ciation in adults. Worse baseline renal function, longer duration of disease and greater frequency of nephrolithiasis/nephrocalcinosis and urological disorders were noted in those who had wor-sening of renal dysfunction during the study period. PMID:21422623

  7. Hereditary Hypokalemic salt-losing tubular disorders

    The inherited hypokalemic tubular disorders are frequently summarized under the heading Bartter Syndrome since they share several clinical and biochemical findings such as renal salt wasting, hypokalemic metabolic alkalosis, normal blood pressure despite hypereninemic hyperaldosteronism and hyperplasia of the juxtaglomerular apparatus. However, careful characterization of the clinical phenotype and correlation with the clinical phenotype and the correlation with the underlying molecular basis justifies the differentiation into at least four distinct disease entities: (i) the hyperprostaglandin E syndrome or antenatal variant of Bartter syndrome (HPS/aBS), which is caused by mutations in either the Na-K-2Cl cotransporter or the potassium channel of the medullary thick ascending limb of Henle's loop; (ii) the HPS/aBS with sensorineural deafness which results from inactivating mutation in the Barttin beta-subunit of the renal chloride channels; (iii) the classic Bartter syndrome caused by mutations in the chloride channel of the distal nephron; and (iv)Gitelman's variant of Bartter syndrome which is caused by mutations of the Na-Cl cotransporter of the distal convoluted tubule. This review will summarize the clinical characteristics of these diseases and progress recently made in the identification of the underlying molecular defects that will hopefully add to the current knowledge of the pathogenesis of these diseases. (author)

  8. The Fourier transform of tubular densities

    Prior, C B

    2012-05-18

    We consider the Fourier transform of tubular volume densities, with arbitrary axial geometry and (possibly) twisted internal structure. This density can be used to represent, among others, magnetic flux or the electron density of biopolymer molecules. We consider tubes of both finite radii and unrestricted radius. When there is overlap of the tube structure the net density is calculated using the super-position principle. The Fourier transform of this density is composed of two expressions, one for which the radius of the tube is less than the curvature of the axis and one for which the radius is greater (which must have density overlap). This expression can accommodate an asymmetric density distribution and a tube structure which has non-uniform twisting. In addition we give several simpler expressions for isotropic densities, densities of finite radius, densities which decay at a rate sufficient to minimize local overlap and finally individual surfaces of the tube manifold. These simplified cases can often be expressed as arclength integrals and can be evaluated using a system of first-order ODEs. © 2012 IOP Publishing Ltd.

  9. Behaviour of concrete filled steel tubular columns under fire

    查晓雄; 钟善桐

    2002-01-01

    A three dimensional nonlinear FE program is used to calculate the fire resistances of concrete filledsteel tubular columns under fire. The temperature distributions in the circular section fire are decided by solvingthe Fourier Transfer Equation , and the mechanical behaviour and failure of concrete filled steel tubular columnsunder fire are thus investigated, and the effects of several parameters on the fire resistance are analysed. Theresults obtained are in good agreement with the Eurocode.

  10. The origin of tubular lava stalactites and other related forms

    Kevin Allred; Carlene Allred

    1998-01-01

    Tubular lava stalactites are often found in lava tubes. Field observations, sample analysis, and comparative studies indicate that these are segregations extruded during cooling from partially crystallized lava al about 1,070 - 1,000 °C. Retrograde boiling (gas pressure) within the lava provides a mechanism to expel the interstitial liquid. In addition to tubular lava stalactites, a variety of other lava features can also result, such as lava helictites, lava coralloids, barnacle-like stretch...

  11. Stresses at weld toes in tubular joints in offshore structures

    Elliott, Kim S.

    1987-01-01

    The accurate prediction of stress concentration factors (SCF) at weld toes is recognised as one of the most important factors in the design, against fatigue failure, of welded tubular joints in offshore structures. The objectives of this work are i) to study the influence of some important tubular joint and weld profile geometric parameters on the elastic SCFs at weld toes, ii) compare these values with strains which could be measured by strain gauges, and iii) to determine plastic-elastic st...

  12. A distal renal tubular acidosis showing hyperammonemia and hyperlactacidemia

    C. Ripoli; Pinna, A.; Marras, S.; M.L. Fenu; Nurchi, A M

    2012-01-01

    Introduction: distal renal tubular acidosis (dRTA) presents itself with variable clinical manifestations and often with late expressions that impact on prognosis. Case report: A 45-day-old male infant was admitted with stopping growth, difficult feeding and vomiting after meals. Clinical tests and labs revealed a type 1 renal tubular acidosis, even if the first blood tests showed ammonium and lactate increase. We had to exclude metabolic diseases before having a certain diagnosis. Conclusions...

  13. Modeling constrained sintering of bi-layered tubular structures

    Tadesse Molla, Tesfaye; Kothanda Ramachandran, Dhavanesan; Ni, De Wei; Esposito, Vincenzo; Teocoli, Francesca; Olevsky, Eugene A.; Bjørk, Rasmus; Pryds, Nini; Kaiser, Andreas; Frandsen, Henrik Lund

    2015-01-01

    densification and stress developments during sintering of tubular bi-layered samples. The correspondence between linear elastic and linear viscous theories is used as a basis for derivation of the model. The developed model is first verified by finite element simulation for sintering of tubular bi-layer system...... thermo-mechanical analysis. Results from the analytical model are found to agree well with finite element simulations as well as measurements from sintering experiment....

  14. Straightening tubular flow for side-by-side visualization.

    Angelelli, Paolo; Hauser, Helwig

    2011-12-01

    Flows through tubular structures are common in many fields, including blood flow in medicine and tubular fluid flows in engineering. The analysis of such flows is often done with a strong reference to the main flow direction along the tubular boundary. In this paper we present an approach for straightening the visualization of tubular flow. By aligning the main reference direction of the flow, i.e., the center line of the bounding tubular structure, with one axis of the screen, we are able to natively juxtapose (1.) different visualizations of the same flow, either utilizing different flow visualization techniques, or by varying parameters of a chosen approach such as the choice of seeding locations for integration-based flow visualization, (2.) the different time steps of a time-dependent flow, (3.) different projections around the center line , and (4.) quantitative flow visualizations in immediate spatial relation to the more qualitative classical flow visualization. We describe how to utilize this approach for an informative interactive visual analysis. We demonstrate the potential of our approach by visualizing two datasets from two different fields: an arterial blood flow measurement and a tubular gas flow simulation from the automotive industry. PMID:22034324

  15. A cut-off tubular geometry of loop space

    Mukhopadhyay, Partha

    2014-01-01

    Motivated by the computation of loop space quantum mechanics as indicated in [7], here we seek a better understanding of the tubular geometry of loop space ${\\cal L}{\\cal M}$ corresponding to a Riemannian manifold ${\\cal M}$ around the submanifold of vanishing loops. Our approach is to first compute the tubular metric of $({\\cal M}^{2N+1})_{C}$ around the diagonal submanifold, where $({\\cal M}^N)_{C}$ is the Cartesian product of $N$ copies of ${\\cal M}$ with a cyclic ordering. This gives an infinite sequence of tubular metrics such that the one relevant to ${\\cal L}{\\cal M}$ can be obtained by taking the limit $N\\to \\infty$. Such metrics are computed by adopting an indirect method where the general tubular expansion theorem of [12] is crucially used. We discuss how the complete reparametrization isometry of loop space arises in the large-$N$ limit and verify that the corresponding Killing equation is satisfied to all orders in tubular expansion. These tubular metrics can alternatively be interpreted as some n...

  16. Reorganization of the endosomal system in Salmonella-infected cells: the ultrastructure of Salmonella-induced tubular compartments.

    Viktoria Krieger

    2014-09-01

    Full Text Available During the intracellular life of Salmonella enterica, a unique membrane-bound compartment termed Salmonella-containing vacuole, or SCV, is formed. By means of translocated effector proteins, intracellular Salmonella also induce the formation of extensive, highly dynamic membrane tubules termed Salmonella-induced filaments or SIF. Here we report the first detailed ultrastructural analyses of the SCV and SIF by electron microscopy (EM, EM tomography and live cell correlative light and electron microscopy (CLEM. We found that a subset of SIF is composed of double membranes that enclose portions of host cell cytosol and cytoskeletal filaments within its inner lumen. Despite some morphological similarities, we found that the formation of SIF double membranes is independent from autophagy and requires the function of the effector proteins SseF and SseG. The lumen of SIF network is accessible to various types of endocytosed material and our CLEM analysis of double membrane SIF demonstrated that fluid phase markers accumulate only between the inner and outer membrane of these structures, a space continual with endosomal lumen. Our work reveals how manipulation of the endosomal membrane system by an intracellular pathogen results in a unique tubular membrane compartmentalization of the host cell, generating a shielded niche permissive for intracellular proliferation of Salmonella.

  17. Proximal tubular injury in Chinese herbs nephropathy: monitoring by neutral endopeptidase enzymuria.

    Nortier, J L; Deschodt-Lanckman, M M; Simon, S; Thielemans, N O; de Prez, E G; Depierreux, M F; Tielemans, C L; Richard, C; Lauwerys, R R; Bernard, A M; Vanherweghem, J L

    1997-01-01

    Neutral endopeptidase (NEP) is a 94 kDa ectoenzyme of the proximal tubule brush border, physiologically released into the urine with apical membrane fragments. As proximal tubular atrophy was a histological hallmark of Chinese herbs nephropathy (CHN), this study firstly determined renal excretion of NEP in healthy control subjects (N = 31), in patients with CHN (N = 26) and in women having consumed Chinese herbs and whose renal function was normal but running the risk of developing CHN (N = 27). Another patient group consisted of female patients with glomerular diseases (N = 12). At the same time, measurements of urinary microproteins (Clara cell protein, retinol binding protein, beta 2-microglobulin and alpha 1-microglobulin) were performed, as indicators of tubular dysfunction. Cell damage was estimated by the excretion of N-acetyl-beta-D-glucosaminidase (NAG). In the control group, the physiological NEP enzymuria was 43.1 micrograms/24 hr (geometric mean). In CHN patients, levels of urinary NEP were significantly decreased in those with moderate renal failure (26.7 micrograms/24 hr; N = 21; P stage renal failure patients (4.35 micrograms/24 hr; N = 5; P two years and in 19 patients at risk during two years, respectively. In the first group, renal function progressively deteriorated in 3 patients, leading them to renal replacement therapy after 38 to 115 weeks. Stable parameters were observed in the remaining 3 patients. A direct correlation between creatinine clearance and NEP excretion was found longitudinally in each case. In the second group, no significant change of urinary NEP levels was observed (45.9 micrograms/24 hr), in parallel with stable renal function. Taken together, these results indicate that, in CHN patients, NEP enzymuria provides a rapid and noninvasive determination of the degree of structural impairment affecting the proximal tubular population and further reflecting the severity of the renal disease. The interest of this urinary marker in

  18. Multi-band emission in a wide wavelength range from tin oxide/Au nanocomposites grown on porous anodic alumina substrate (AAO)

    The photoluminescence (PL) properties of tin oxide nanostructures are investigated. Three samples of different morphology, induced by deposition process and various geometrical features of nanoporous anodic aluminum oxide (AAO) substrate, are analyzed. X-ray photoelectronic spectroscopy (XPS) analysis reveals the presence of two forms of tin oxide on the surface of all studied samples: SnO and SnO2. The former form is typical for reduced surface with bridging oxygen atoms and every other row of in-plane oxygen atoms removed. The oxygen defects give rise to a strong emission in visible region. Two intense PL peaks are observed centered at about 540 (band I) and 620 (band II) nm. The origin of these bands was ascribed to the recombination of electrons from the conduction band (band I) and shallow traps levels (band II) to the surface oxygen vacancy levels. Upon deposition of Au nanoparticles on the top of tin oxide nanostructures the emission at 540 and 620 nm disappears and a new band (band III) occurs in the range >760 nm. The PL mechanism operating in the studied systems is discussed. The tin oxide/Au nanocomposites can be used as efficient multi-band light emitters in a wide (from visible to near infrared) wavelength range.

  19. Renal proximal tubular dysgenesis associated with severe neonatal hemosiderotic liver disease.

    Bale, P M; Kan, A E; Dorney, S F

    1994-01-01

    We report the necropsy findings for three infants with the unusual combination of proximal renal tubular dysgenesis and severe congenital liver disease with excessive iron in several organs resembling neonatal hemochromatosis. Two of the infants were caucasian siblings and one was an Australian aborigine. One died in utero at 35 weeks of gestation and two died at 7 days. The liveborn infants presented with anuria and liver failure. The livers all showed marked loss of hepatocytes and replacement by pseudotubules in the collapsed lobules. The liveborn infants also showed giant cell transformation of hepatocytes, small regenerative nodules, cholestasis, and normal bile ducts. Absence of proximal renal convolutions was confirmed by epithelial membrane antigen positivity in nearly all tubules. In each family there was another sibling with congenital liver disease, fatal in one case, but no renal tubular dysgenesis. No infection or metabolic disease was uncovered in any of our patients, and the cause of the hepatocyte destruction was not determined. The combination in three infants of two rare congenital diseases could be genetic or acquired in utero from the same etiological agent. Alternatively, the absence of proximal convolutions could be secondary to hypoperfusion, perhaps because of shock due to extensive necrosis of hepatocytes. PMID:8066004

  20. Multilayer chitosan-based open tubular capillary anion exchange column with integrated monolithic capillary suppressor

    Highlights: ► Uses a multilayer chitosan–glutaraldehyde coating as anion exchanger. ► Uses a methacrylate-acrylic acid polymer monolith as suppressor. ► Demonstrates first integral suppressor open tubular anion chromatography. - Abstract: We describe a multilayered open tubular anion exchange column fabricated by alternately pumping solutions of chitosan and glutaraldehyde. The column is terminated in an integrally bonded monolithic suppressor cast around a mandrel of a tungsten wire, composed of an acrylic acid (AA)–ethylene dimethacrylate (EDMA) monolith that is made with sufficient porogen for the monolith to function as a membrane. For a 4.5 m long 75 μm bore column coated with 24 successive layers of the condensation polymer (estimated to contain ∼72 molecular layers) and coupled to 1 cm length of a suppressor fabricated with 55–60% AA, effective separation of several common anions (F−, Cl−, NO2−, Br−, NO3−, average number of theoretical plates ∼12,000) and adequate suppression of 1 mM KOH used as eluent was observed at a flow rate of 800 nL min−1 to obtain sub-picomol detection limits at an operating pressure of ∼1 bar. The separation is not time efficient but the system can be meritorious in unique niche applications where a small form factor is desired and liquid volume and power consumption are more important than separation speed.

  1. Fatigue Life of High-Strength Steel Offshore Tubular Joints

    Petersen, Rasmus Ingomar; Agerskov, Henning; Lopez Martinez, Luis

    1996-01-01

    In the present investigation, the fatigue life of tubular joints in offshore steel structures is studied. Two test series on full-scale tubular joints have been carried through. One series was on joints in conventional offshore structural steel, and the other series was on joints in high-strength......In the present investigation, the fatigue life of tubular joints in offshore steel structures is studied. Two test series on full-scale tubular joints have been carried through. One series was on joints in conventional offshore structural steel, and the other series was on joints in high...... from Ø 324-610 mm tubes, and the joints were loaded in in-plane bending. Both fatigue tests under constant amplitude loading and tests with a stochastic loading that is realistic in relation to offshore structures, are included in the investigation.A comparison between constant amplitude and variable...... amplitude fatigue test results showed shorter fatigue lives in variable amplitude loading than should be expected from the linear fatigue damage accumulation formula. Furthermore, the fatigue tests on high-strength steel tubular joints showed slightly longer fatigue lives than those obtained in...

  2. Power generation characteristics of tubular type SOFC by wet process

    Tajiri, H.; Nakayama, T. [Kyushu Electric Power Company, Inc., Fukuoka (Japan); Kuroishi, M. [TOTO Ltd., Kanagawa (Japan)] [and others

    1996-12-31

    The development of a practical solid oxide fuel cell requires improvement of a cell performance and a cell manufacturing technology suitable for the mass production. In particular tubular type SOFC is thought to be superior in its reliability because its configuration can avoid the high temperature sealing and reduce the thermal stress resulting from the contact between cells. The authors have fabricated a tubular cell with an air electrode support by a wet processing technique, which is suitable for mass production in improving a power density. To enhance the power output of the module, the Integrated Tubular-Type (ITT) cell has been developed. This paper reports the performance of the single cells with various active anode areas and the bundle with series-connected 9-ITT cells with an active anode area of 840 cm{sup 2}.

  3. Numerical study of cavitation flows inside a tubular pumping station

    Based on RNG k−ε turbulence model and the full cavitation model, the cavitation flows inside a low-head tubular-pump model were predicted by using the FLUENT software. For a operating case of given flow rate, cavitation happens near the inlet on the suction surfaces of the impeller blades at the initial cavitating stage, and the cavitating area spreads to the impeller passage and hub as NPSH (net positive suction head) decreases, which will affect energy transformation. For various operating cases of cavitation flows at the given flow rates, the predicted velocity and pressure distributions as well as the vapor volumetric fraction are systematically analyzed. Finally, the cavitation performance curve of the tubular-pump model is obtained by means of the further post-processing. All the comparisons and analysis can be further employed to optimize the hydraulic and structural design of the tubular pump and to guide its safe operation.

  4. Tubular localization and expressional dynamics of aquaporins in the kidney of seawater-challenged Atlantic salmon

    Engelund, Morten Buch; Madsen, Steffen S

    2015-01-01

    Most vertebrate nephrons possess an inherited ability to secrete fluid in normal or pathophysiological states. We hypothesized that renal aquaporin expression and localization are functionally regulated in response to seawater and during smoltification in Atlantic salmon and thus reflect a shift in...... renal function from filtration towards secretion. We localized aquaporins (Aqp) in Atlantic salmon renal tubular segments by immunohistochemistry and monitored their expressional dynamics using RT-PCR and immunoblotting. Three aquaporins: Aqpa1aa, Aqp1ab and Aqp8b and two aquaglyceroporins Aqp3a and Aqp....... Aqp10b was expressed apically and along the lateral membrane. Aqp8b was mainly basolateral and Aqp1ab was located in sub-apical intracellular compartments. mRNAs of aqp8b and aqp10b were higher in FW smolts compared to FW parr, whereas the opposite was true for aqp1aa. Aqp mRNA levels changed in...

  5. The influence of polymeric membrane gas spargers on hydrodynamics and mass transfer in bubble column bioreactors

    Tirunehe, Gossay; Norddahl, B.

    2016-01-01

    Gas sparging performances of a flat sheet and tubular polymeric membranes were investigated in 3.1 m bubble column bioreactor operated in a semi batch mode. Air–water and air–CMC (Carboxymethyl cellulose) solutions of 0.5, 0.75 and 1.0 % w/w were used as interacting gas–liquid mediums. CMC....../s. The study indicated that the tubular membrane sparger produced the highest gas holdup and densely populated fine bubbles with narrow size distribution. An increase in liquid viscosity promoted a shift in bubble size distribution to large stable bubbles and smaller specific interfacial area. The tubular...... membrane sparger achieved greater interfacial area and an enhanced overall mass transfer coefficient (KLa) by a factor of 1.2–1.9 compared to the flat sheet membrane....

  6. Disturbances of the sarcoplasmic reticulum and transverse tubular system in 24-h electrostimulated fast-twitch skeletal muscle

    Frías, J A; Cadefau, J A; Prats, C;

    2005-01-01

    muscle to low-frequency stimulation, Pflugers Arch. 424 (1993) 529-537). To assess the involvement of sarcoplasmic reticulum and transverse tubular system in this force impairment, we isolated microsomal fractions from stimulated and control (contralateral, unstimulated) muscles on discontinuous sucrose...... damage to longitudinal sarcoplasmic reticulum and swelling of t-tubules revealed by electron microscopy. The ultrastructural changes observed here reflect exercise-induced damage of membrane systems that might severely compromise muscle function. Since this process is reversible, we suggest that it may...

  7. Pulse shear stress for anaerobic membrane bioreactor fouling control.

    Yang, Jixiang; Spanjers, Henri; van Lier, Jules B

    2011-01-01

    Increase of shear stress at membrane surfaces is a generally applied strategy to minimize membrane fouling. It has been reported that a two-phase flow, better known as slug flow, is an effective way to increase shear stress. Hence, slug flow was introduced into an anaerobic membrane bioreactor for membrane fouling control. Anaerobic suspended sludge was cultured in an anaerobic membrane bioreactor (AMBR) operated with a side stream inside-out tubular membrane unit applying sustainable flux flow regimes. The averaged particle diameter decreased from 20 to 5 microm during operation of the AMBR. However, the COD removal efficiency did not show any significant deterioration, whereas the specific methanogenic activity (SMA) increased from 0.16 to 0.41 gCOD/g VSS/day. Nevertheless, the imposed gas slug appeared to be insufficient for adequate fouling control, resulting in rapidly increasing trans membrane pressures (TMP) operating at a flux exceeding 16 L/m2/h. Addition of powdered activated carbon (PAC) enhanced the effect of slug flow on membrane fouling. However, the combined effect was still considered as not being significant. The tubular membrane was subsequently equipped with inert inserts for creating a locally increased shear stress for enhanced fouling control. Results show an increase in the membrane flux from 16 L/m2/h to 34 L/m2/h after the inserts were mounted in the membrane tube. PMID:22097007

  8. Electrocatalytic oxidation of n-propanol to produce propionic acid using an electrocatalytic membrane reactor.

    Li, Jiao; Li, Jianxin; Wang, Hong; Cheng, Bowen; He, Benqiao; Yan, Feng; Yang, Yang; Guo, Wenshan; Ngo, Huu Hao

    2013-05-18

    An electrocatalytic membrane reactor assembled using a nano-MnO2 loading microporous Ti membrane as an anode and a tubular stainless steel as a cathode was used to oxidize n-propanol to produce propionic acid. The high efficiency and selectivity obtained is related to the synergistic effect between the reaction and separation in the reactor. PMID:23572114

  9. Segmental tubular sodium reabsorption in type 1 diabetes

    Dieperink, H; Eshøj, O; Leyssac, P P;

    1993-01-01

    Segmental tubular sodium reabsorption in Type 1 (insulin-dependent) diabetes was measured in 36 patients in a cross-sectional study including one group (n = 13) without significant albuminuria (UalbV < 30 mg 24 h-1), one group (n = 16) with albuminuria in the range from 30 to 300 mg 24 h-1, and a...... group (n = 7) with nephropathy (UalbV > 300 mg 24 h-1). Lithium clearance was used to measure end proximal delivery. From end proximal delivery, 51Cr-EDTA clearance (GFR) and sodium clearance, segmental tubular reabsorption was calculated. For all patients, GFR was directly correlated with end proximal...

  10. Study of Internal Ballistics of Hepta-Tubular Powders

    M. C. Gupta

    1959-04-01

    Full Text Available In thin paper a solution of the system of equations in Internal Ballistics of a, conventional gun has been discussed for the hepta-tubular powder. The shot-start pressure is taken diffe- rent from zero and the covolume correction also is taken I. into amount and thus some of the results of Tavernierl who has taken zero shot-start preasure and has neglected the . covolume~omtion, have been generalised. It has been. found out that the maximum pressure in the case of hepta-tubular powders always occurs before the all-burnt position.

  11. Novel non-aqueous nano-composite electrolyte membranes

    Singh, M.; Missan, H.P.S. [West Indies Univ., St. Augustine (Trinidad and Tobago). Dept. of Physics

    2009-07-01

    Fuel cell technology is increasingly being considered as a replacement for non-renewable energy sources. However, the use of commercial perfluorinated sulfonated membranes such as Nafion increases the cost of fuel cells. This paper discussed new and novel non-aqueous proton conducting membranes based on an ionic liquid ternary system containing nano-tubular inorganic oxides. Experiments conducted to demonstrate the system showed that a high non-aqueous ionic conductivity of 10-2 S per cm at temperatures up to 150 degrees can be obtained. Thermographic analyses determined that the membranes maintain stability up to temperatures of 250 degrees C. It was concluded that the addition of a nano-tubular composite phase optimize membrane morphology and increase thermal stability.

  12. Lipid Gymnastics: Tethers and Fingers in membrane

    Tayebi, Lobat; Miller, Gregory; Parikh, Atul

    2009-03-01

    A significant body of evidence now links local mesoscopic structure (e.g., shape and composition) of the cell membrane with its function; the mechanisms by which cellular membranes adopt the specific shapes remain poorly understood. Among all the different structures adopted by cellular membranes, the tubular shape is one of the most surprising one. While their formation is typically attributed to the reorganization of membrane cytoskeleton, many exceptions exist. We report the instantaneous formation of tubular membrane mesophases following the hydration under specific thermal conditions. The shapes emerge in a bimodal way where we have two distinct diameter ranges for tubes, ˜20μm and ˜1μm, namely fat fingers and narrow tethers. We study the roughening of hydrated drops of 3 lipids in 3 different spontaneous curvatures at various temp. and ionic strength to figure out the dominant effect in selection of tethers and fingers. Dynamics of the tubes are of particular interest where we observe four distinct steps of birth, coiling, uncoiling and retraction with different lifetime on different thermal condition. These dynamics appear to reflect interplay between membrane elasticity, surface adhesion, and thermal or hydrodynamic gradient.

  13. In vitro hydrodynamic evaluation of a biovalve with stent (tubular leaflet type) for transcatheter pulmonary valve implantation.

    Sumikura, Hirohito; Nakayama, Yasuhide; Ohnuma, Kentaro; Kishimoto, Satoru; Takewa, Yoshiaki; Tatsumi, Eisuke

    2015-12-01

    We have been developing an autologous heart valve-shaped tissue with a stent (stent-biovalve) for transcatheter pulmonary valve implantation (TPVI) using "in-body tissue architecture" technology. In this study, the hydrodynamic performance of a stent-biovalve with tubular leaflets was evaluated by changing its leaflet height in an in vitro test in order to determine the appropriate stent-biovalve form for the pulmonary valve. A specially designed, self-expandable, stent-mounted, cylindrical acrylic mold was placed in a dorsal subcutaneous pouch of goat, and the implant was extracted 2 months later. Only the cylindrical acrylic mold was removed from the implant, and a tubular hollow structure of membranous connective tissue impregnated with the stent strut was obtained. Half of tubular tissue was completely folded in half inwards, and 3 commissure parts were connected to form 3 leaflets, resulting in the preparation of a stent-biovalve with tubular leaflets (25-mm ID). The stent-biovalve with adjusting leaflet height (13, 14, 15, 17, 20, and 25 mm) was fixed to a specially designed pulsatile mock circulation circuit under pulmonary valve conditions using 37 °C saline. The mean pressure difference and effective orifice area were better than those of the biological valve. The lowest and highest leaflet heights had a high regurgitation rate due to lack of coaptation or prevention of leaflet movement, respectively. The lowest regurgitation (ca. 11%) was observed at a height of 15 mm. The leaflet height was found to significantly affect the hydrodynamics of stent-biovalves, and the existence of an appropriate leaflet height became clear. PMID:26141924

  14. Fission of a multiphase membrane tube

    Allain, J M; Roux, A; Storm, C; Allain, Jean-Marc; Amar, Martine Ben; Proxy, Jean-Francois Joanny; Roux, Aurelien; Storm, Cornelis; ccsd-00001468, ccsd

    2004-01-01

    A common mechanism for intracellular transport is the use of controlled deformations of the membrane to create spherical or tubular buds. While the basic physical properties of homogeneous membranes are relatively well-known, the effects of inhomogeneities within membranes are very much an active field of study. Membrane domains enriched in certain lipids in particular are attracting much attention, and in this Letter we investigate the effect of such domains on the shape and fate of membrane tubes. Recent experiments have demonstrated that forced lipid phase separation can trigger tube fission, and we demonstrate how this can be understood purely from the difference in elastic constants between the domains. Moreover, the proposed model predicts timescales for fission that agree well with experimental findings.

  15. Water desalination by air-gap membrane distillation using meltblown polypropylene nanofiber membrane

    Rosalam, S.; Chiam, C. K.; Widyaparamitha, S.; Chang, Y. W.; Lee, C. A.

    2016-06-01

    This paper presents a study of air gap membrane distillation (AGMD) using meltblown polypropylene (PP) nanofiber membrane to produce fresh water via desalination process. PP nanofiber membranes with the effective area 0.17 m2 are tested with NaCl solutions (0.5 - 4.0 wt.%) and seawater as the feed solutions (9400 - 64800 μS/cm) in a tubular membrane module. Results show that the flux decreases with increasing the membrane thickness from 547 to 784 μm. The flux increases with the feed flow rate and temperature difference across the membrane. The feed concentration affects the flux insignificantly. The AGMD system can reject the salts at least 96%. Water vapor permeation rate is relatively higher than solute permeation rate resulting in the conductivity value of permeate decreases when the corresponding flux increases. The AGMD system produces the fresh water (200 - 1520 μS/cm) that is suitable for drinking, fisheries or irrigation.

  16. Muscle imaging in patients with tubular aggregate myopathy caused by mutations in STIM1

    Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro; Nadaj-Pakleza, Aleksandra; Vialle, Marc; Fattori, Fabiana; Vissing, John; Ricci, Enzo; Bertini, Enrico

    2015-01-01

    Tubular aggregate myopathy is a genetically heterogeneous disease characterized by tubular aggregates as the hallmark on muscle biopsy. Mutations in STIM1 have recently been identified as one genetic cause in a number of tubular aggregate myopathy cases. To characterize the pattern of muscle involvement in this disease, upper and lower girdles and lower limbs were imaged in five patients with mutations in STIM1, and the scans were compared with two patients with tubular aggregate myopathy not...

  17. Graphene-Coated Hollow Fiber Membrane as the Cathode in Anaerobic Electrochemical Membrane Bioreactors - Effect of Configuration and Applied Voltage on Performance and Membrane Fouling.

    Werner, Craig M; Katuri, Krishna P; Hari, Ananda Rao; Chen, Wei; Lai, Zhiping; Logan, Bruce E; Amy, Gary L; Saikaly, Pascal E

    2016-04-19

    Electrically conductive, graphene-coated, hollow-fiber porous membranes were used as cathodes in anaerobic electrochemical membrane bioreactors (AnEMBRs) operated at different applied voltages (0.7 and 0.9 V) using a new rectangular reactor configuration compared to a previous tubular design (0.7 V). The onset of biofouling was delayed and minimized in rectangular reactors operated at 0.9 V compared to those at 0.7 V due to higher rates of hydrogen production. Maximum transmembrane pressures for the rectangular reactor were only 0.10 bar (0.7 V) or 0.05 bar (0.9 V) after 56 days of operation compared to 0.46 bar (0.7 V) for the tubular reactor after 52 days. The thickness of the membrane biofouling layer was approximately 0.4 μm for rectangular reactors and 4 μm for the tubular reactor. Higher permeate quality (TSS = 0.05 mg/L) was achieved in the rectangular AnEMBR than that in the tubular AnEMBR (TSS = 17 mg/L), likely due to higher current densities that minimized the accumulation of cells in suspension. These results show that the new rectangular reactor design, which had increased rates of hydrogen production, successfully delayed the onset of cathode biofouling and improved reactor performance. PMID:26691927

  18. Graphene-coated hollow fiber membrane as the cathode in anaerobic electrochemical membrane bioreactors – Effect of configuration and applied voltage on performance and membrane fouling

    Werner, Craig

    2015-12-22

    Electrically conductive, graphene-coated hollow-fiber porous membranes were used as cathodes in anaerobic electrochemical membrane bioreactors (AnEMBRs) operated at different applied voltages (0.7 V and 0.9 V) using a new rectangular reactor configuration, compared to a previous tubular design (0.7 V). The onset of biofouling was delayed and minimized in rectangular reactors operated at 0.9 V, compared to those at 0.7 V due to higher rates of hydrogen production. Maximum transmembrane pressures for the rectangular reactor were only 0.10 bar (0.7 V) or 0.05 bar (0.9 V) after 56 days of operation, compared to 0.46 bar (0.7 V) for the tubular reactor after 52 days. The thickness of the membrane biofouling layer was approximately 0.4 µm for rectangular reactors and 4 µm for the tubular reactor. Higher permeate quality (TSS = 0.05 mg/L) was achieved in the rectangular AnEMBR than the tubular AnEMBR (TSS = 17 mg/L), likely due to higher current densities that minimized the accumulation of cells in suspension. These results show that the new rectangular reactor design, which had increased rates of hydrogen production, successfully delayed the onset of cathode biofouling and improved reactor performance.

  19. Membrane dynamics

    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...

  20. Subanalytic Bundles and Tubular Neighbourhoods of Zero-Loci

    Vishwambhar Pati

    2003-08-01

    We introduce the natural and fairly general notion of a subanalytic bundle (with a finite dimensional vector space of sections) on a subanalytic subset of a real analytic manifold , and prove that when is compact, there is a Baire subset of sections in whose zero-loci in have tubular neighbourhoods, homeomorphic to the restriction of the given bundle to these zero-loci.

  1. Urinary Markers of Tubular Injury in Early Diabetic Nephropathy

    Temesgen Fiseha

    2016-01-01

    Full Text Available Diabetic nephropathy (DN is a common and serious complication of diabetes associated with adverse outcomes of renal failure, cardiovascular disease, and premature mortality. Early and accurate identification of DN is therefore of critical importance to improve patient outcomes. Albuminuria, a marker of glomerular involvement in early renal damage, cannot always detect early DN. Thus, more sensitive and specific markers in addition to albuminuria are needed to predict the early onset and progression of DN. Tubular injury, as shown by the detection of tubular injury markers in the urine, is a critical component of the early course of DN. These urinary tubular markers may increase in diabetic patients, even before diagnosis of microalbuminuria representing early markers of normoalbuminuric DN. In this review we summarized some new and important urinary markers of tubular injury, such as neutrophil gelatinase associated lipocalin (NGAL, kidney injury molecule-1 (KIM-1, liver-type fatty acid binding protein (L-FABP, N-acetyl-beta-glucosaminidase (NAG, alpha-1 microglobulin (A1M, beta 2-microglobulin (B2-M, and retinol binding protein (RBP associated with early DN.

  2. Urinary Markers of Tubular Injury in Early Diabetic Nephropathy.

    Fiseha, Temesgen; Tamir, Zemenu

    2016-01-01

    Diabetic nephropathy (DN) is a common and serious complication of diabetes associated with adverse outcomes of renal failure, cardiovascular disease, and premature mortality. Early and accurate identification of DN is therefore of critical importance to improve patient outcomes. Albuminuria, a marker of glomerular involvement in early renal damage, cannot always detect early DN. Thus, more sensitive and specific markers in addition to albuminuria are needed to predict the early onset and progression of DN. Tubular injury, as shown by the detection of tubular injury markers in the urine, is a critical component of the early course of DN. These urinary tubular markers may increase in diabetic patients, even before diagnosis of microalbuminuria representing early markers of normoalbuminuric DN. In this review we summarized some new and important urinary markers of tubular injury, such as neutrophil gelatinase associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver-type fatty acid binding protein (L-FABP), N-acetyl-beta-glucosaminidase (NAG), alpha-1 microglobulin (A1M), beta 2-microglobulin (B2-M), and retinol binding protein (RBP) associated with early DN. PMID:27293888

  3. Hemodynamic and tubular changes induced by contrast media.

    Caiazza, Antonella; Russo, Luigi; Sabbatini, Massimo; Russo, Domenico

    2014-01-01

    The incidence of acute kidney injury induced by contrast media (CI-AKI) is the third cause of AKI in hospitalized patients. Contrast media cause relevant alterations both in renal hemodynamics and in renal tubular cell function that lead to CI-AKI. The vasoconstriction of intrarenal vasculature is the main hemodynamic change induced by contrast media; the vasoconstriction is accompanied by a cascade of events leading to ischemia and reduction of glomerular filtration rate. Cytotoxicity of contrast media causes apoptosis of tubular cells with consequent formation of casts and worsening of ischemia. There is an interplay between the negative effects of contrast media on renal hemodynamics and on tubular cell function that leads to activation of renin-angiotensin system and increased production of reactive oxygen species (ROS) within the kidney. Production of ROS intensifies cellular hypoxia through endothelial dysfunction and alteration of mechanisms regulating tubular cells transport. The physiochemical characteristics of contrast media play a critical role in the incidence of CI-AKI. Guidelines suggest the use of either isoosmolar or low-osmolar contrast media rather than high-osmolar contrast media particularly in patients at increased risk of CI-AKI. Older age, presence of atherosclerosis, congestive heart failure, chronic renal disease, nephrotoxic drugs, and diuretics may multiply the risk of CI-AKI. PMID:24678510

  4. Modelling the cardiac transverse-axial tubular system

    Pásek, Michal; Šimurda, J.; Christé, G.; Orchard, C.

    2008-01-01

    Roč. 96, - (2008), s. 226-246. ISSN 0079-6107 Institutional research plan: CEZ:AV0Z20760514 Keywords : cardiac cell * transverse-axial tubular system * quantitative modelling Subject RIV: BO - Biophysics Impact factor: 6.388, year: 2008

  5. Glutamatergic signaling maintains the epithelial phenotype of proximal tubular cells

    Bozic, M.; de Rooij, J.; Parisi, E.; Ortega, M.R.; Fernandez, E.; Valdivielso, J.M.

    2011-01-01

    Epithelial-mesenchymal transition (EMT) contributes to the progression of renal tubulointerstitial fibrosis. The N-methyl-d-aspartate receptor (NMDAR), which is present in proximal tubular epithelium, is a glutamate receptor that acts as a calcium channel. Activation of NMDAR induces actin rearrange

  6. Ozonation and/or Coagulation - Ceramic Membrane Hybrid for Filtration of Impaired-Quality Source Waters

    Ha, Changwon

    2013-09-01

    When microfiltration (MF) and ultrafiltration (UF) membranes are applied for drinking water treatment/wastewater reuse, membrane fouling is an evitable problem, causing the loss of productivity over time. Polymeric membranes have been often reported to experience rapid and/or problematical fouling, restraining sustainable operation. Ceramic membranes can be effectively employed to treat impaired-quality source waters due to their inherent robustness in terms of physical and chemical stability. This research aimed to identify the effects of coagulation and/or ozonation on ceramic membrane filtration for seawater and wastewater (WW) effluent. Two different types of MF and UF ceramic membranes obtained by sintering (i.e., TAMI made of TiO2+ZrO2) and anodic oxidation process (i.e., AAO made of Al2O3) were employed for bench-scale tests. Precoagulation was shown to play an important role in both enhancing membrane filterability and natural organic matter (NOM) removal efficacy for treating a highorganic surface water. The most critical factors were found to be pH and coagulant dosage with the highest efficiency resulting under low pH and high coagulant dose. Due to the ozone-resistance nature of the ceramic membranes, preozonation allowed the ceramic membranes to be operated at higher flux, especially leading to significant flux improvement when treating seawater in the presence of calcium and magnesium. 4 Dissolved ozone in contact with the TAMI ceramic membrane surface accelerated the formation of hydroxyl (˙OH) radicals in WW effluent treatment. Flux restoration of both ceramic membranes, fouled with seawater and WW effluent, was efficiently achieved by high backwash (BW) pressure and ozone in chemically enhanced backwashing (CEB). Ceramic membranes exhibited a pH-dependent permeate flux while filtering WW effluent, showing reduced fouling with increased pH. On the other hand, for filtering seawater, differences in permeate flux between the two membranes was

  7. EGCG decreases binding of calcium oxalate monohydrate crystals onto renal tubular cells via decreased surface expression of alpha-enolase.

    Kanlaya, Rattiyaporn; Singhto, Nilubon; Thongboonkerd, Visith

    2016-06-01

    Crystal retention on tubular cell surface inside renal tubules is considered as the earliest and crucial step for kidney stone formation. Therapeutics targeting this step would cease the development of kidney stone. This study thus aimed to investigate the potential role of epigallocatechin-3-gallate (EGCG), a major antioxidant found in green tea leaves, in the reduction of calcium oxalate monohydrate (COM) crystal binding onto renal tubular cells. Pretreatment of the cells with EGCG for up to 6 h significantly diminished crystal-binding capability in a dose-dependent manner. Indirect immunofluorescence assay without and with cell permeabilization followed by laser-scanning confocal microscopy revealed that EGCG significantly reduced surface expression of alpha-enolase, whereas its intracellular level was increased. Western blot analysis confirmed such contradictory changes in membrane and cytosolic fractions of EGCG-treated cells, whereas the total level in whole cell lysate remained unchanged. Moreover, overexpression of surface alpha-enolase and enhancement of cell-crystal adhesion induced by 10 mM sodium oxalate were completely abolished by EGCG. Taken together, these data indicate that EGCG decreases binding of COM crystals onto renal tubular cells by decreasing the surface expression of alpha-enolase via re-localization or inhibition of alpha-enolase shuttling from the cytoplasm to the plasma membrane. These findings may also explain the effects of EGCG in reducing COM crystal deposition in previous animal models of kidney stone disease. Thus, EGCG may be useful for the prevention of new or recurrent stone formation. PMID:26898643

  8. Performance comparison between planar and tubular-shaped PEM fuel cells by three-dimensional numerical simulation

    Coursange, J.F.; Hourri, A.; Hamelin, J. [Universite du Quebec a Trois-Rivieres, Institut de Recherche sur l' hydrogene, 3351, Boul. Des Forges, C.P. 500, Trois-Rivieres (QC), G9A 5H7 (Canada)

    2003-08-01

    The results of a numerical simulation of the current distribution of a three-dimensional, tubular shaped, proton exchange membrane fuel cell model are presented. An integrated flow and current density model to predict current density distributions in two dimensions along the membrane has been developed. The numerical model has a cylindrical geometry that includes diffusion layers on the anode and cathode side, the anode being the inner most electrode, and solves the same primary flow related variables along the channels and the diffusion layers. The simulation was performed with commercial flow solver software where a control volume approach was used and source term equations that characterize the electrochemical aspects of the fuel cell have been added. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  9. AAO Observer - August 2011 Edition

    Brough, Sarah

    2011-01-01

    This edition of the Australian Astronomical Observatory Observer contains articles on the commissioning of the new SAMI instrument giving the first hexabundle galaxy spectra; galaxy parameter variations across and through the 6dFGS Fundamental Plane; an introduction to the new Dragonfly stellar interferometer; an update on the RAdial VElocity (RAVE) survey at half a million spectra; the Magellanic Quasars Survey; the Integrated Photonic Spectrograph's first look at the heart of the Scorpion; using AAOMega to measure the age of the young open cluster IC2602; making MANIFEST fibres for the Giant Magellan Telescope and a Voyage through Filaments of Galaxies. The Observer also contains thoughts on diversity in the astronomy community and reports on the recent Supernovae and their Host Galaxies conference and the 2011 Science Meets Parliament. In addition there are the usual features of the AUSGO Corner, Epping News and Letter from Coona.

  10. Rejection and Critical Flux of Calcium Sulphate in a Ceramic Titanium Dioxide Nanofiltration Membrane

    Ahmed, Amer Naji

    2013-01-01

    ABSTRACTThis thesis describes the rejection efficiency and the fouling behaviour of calcium sulphate solutes in a 1 nm tubular ceramic titanium dioxide nanofiltration membrane.Calcium sulphate is considered as one of the greatest scaling potential inorganic salts that responsible for membrane fouling which represents a main challenge in the expansion of membrane processes for desalination of brackish and saline water. The surface charge type and magnitude for the composite amphoteric TiO_2 me...

  11. Effect of PVP Intermediate Layer on the Properties of SAPO 34 Membrane

    Jugal K. Das; Nandini Das; Sibdas Bandyopadhyay

    2012-01-01

    SAPO 34 zeolite membranes were prepared on a tubular mullite support. Before membrane preparation, the support surfaces were coated with seed crystals. Seeds particles were prepared by hydrothermal synthesis. Before seeding, the substrates were treated with polyvinylpyrrolidone (PVP) to orient the seeds. Both the treated and untreated supports were seeded, and membranes were synthesized on those support tubes by ex situ hydrothermal method. The PVP molecule exists in the two resonance structu...

  12. Simulation Study of a Dense Polymeric Catalytic Membrane Reactor with Plug-flow Pattern

    José M. Sousa; Adélio Mendes

    2003-01-01

    A theoretical study on a tubular membrane reactor, assuming isothermal operation, plugflow pattern and using a dense polymeric catalytic membrane, is performed. The reactor conversion for an A#8644;B equilibrium gas-phase reaction is analyzed, considering the influence of the reactants and products diffusion and sorption coefficients, the influence of the total pressure gradient and the influence of the ratio between the membrane thickness and its internal radius as well as the influence of t...

  13. Renal proximal tubular cell fibronectin accumulation in response to glucose is polyol pathway dependent

    Morrisey; Steadman; Williams; Phillips

    1999-06-01

    Thickening and reduplication of the tubular basement membrane has been reported as an early event in diabetic nephropathy. In the current study we have examined the polar requirements of proximal tubular cells for the D-glucose stimulated accumulation of fibronectin. We also examined the mechanism by which glucose led to accumulation of fibronectin, with particular emphasis on the polyol pathway. Incubation of confluent monolayers of LLC-PK1 cells grown on tissue culture inserts with 25 mM D-glucose on either their apical or basolateral aspect, led to fibronectin accumulation in the basolateral compartment. This reached statistical significance 24 h following apical addition of glucose (2.7 fold increase compared to 5 mM D-glucose, p = 0.007, n = 6), and 12 h after the basolateral addition of glucose (2.54 fold increase compared to 5 mM D-glucose, p = 0.02, n = 6). The increase in fibronectin concentration in response to glucose was inhibited by the aldose reductase inhibitor sorbinil. At a dose of 100&mgr;M sorbinil there was 59% inhibition of fibronectin accumulation in response to glucose, 48 h after the addition of the inhibitor (4.76 +/- 1.4 vs 11.53 +/- 1.41, mean +/- SD, p = 0.01, n = 3). Exposure of cells to glucose at either their apical or basolateral aspect lead to accumulation of intracellular glucose and polyol pathway activation, as assessed by sorbitol accumulation. Accumulation of intracellular glucose and hence subsequent polyol pathway activation occurred independently of transport of glucose by either apical sodium linked glucose transporter (SLGT) or basolateral GLUT 1. The data demonstrate that fibronectin generation in response to glucose was non-polar in terms application of glucose, but polar in terms of fibronectin accumulation. Furthermore modulation of fibronectin was mediated by polyol pathway activation, and more specifically related to the metabolism of sorbitol to fructose. PMID:10354307

  14. Investigations on a new internally-heated tubular packed-bed methanol–steam reformer

    Nehe, Prashant

    2015-05-01

    Small-scale reformers for hydrogen production through steam reforming of methanol can provide an alternative solution to the demand of continuous supply of hydrogen gas for the operation of Proton Exchange Membrane Fuel Cells (PEMFCs). A packed-bed type reformer is one of the potential designs for such purpose. An externally heated reformer has issues of adverse lower temperature in the core of the reformer and significant heat loss to the environment thus impacting its performance. Experimental and numerical studies on a new concept of internally heated tubular packed-bed methanol-steam reformer have been reported in this paper with improved performance in terms of higher methanol conversion and reduced heat losses to surroundings. CuO/ZnO/Al2O3 is used as the catalyst for the methanol-steam reforming reaction and a rod-type electric heater at the center of the reactor is used for supplying necessary heat for endothermic steam reforming reaction. The vaporizer and the reformer unit with a constant volume catalyst bed are integrated in the annular section of a tubular reformer unit. The performance of the reformer was investigated at various operating conditions like feed rate of water-methanol mixture, mass of the catalyst and reforming temperature. The experimental and numerical results show that the methanol conversion and CO concentration increase with internal heating for a wide range of operating conditions. The developed reformer unit generates 50-80W (based on lower heating value) of hydrogen gas for applications in PEMFCs. For optimized design and operating conditions, the reformer unit produced 298sccm reformed gas containing 70% H2, 27% CO2 and 3% CO at 200-240°C which can produce a power output of 25-32W assuming 60% fuel cell efficiency and 80% of hydrogen utilization in a PEMFC. © 2015 Hydrogen Energy Publications, LLC.

  15. Membrane fusion

    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....

  16. Luminous effectiveness of tubular light-guides in tropics

    Darula, Stanislav; Kittler, Richard; Kocifaj, Miroslav [ICA, Slovak Academy of Sciences, 9, Dubravska Road, 845 03 Bratislava (Slovakia)

    2010-11-15

    Novel tubular light-guides with a transparent hemispherical cupola placed on an unobstructed flat roof collect all sunlight and skylight available at ground level year round. This advantage is heightened in the dry and sunny tropical regions where the sun rises to very high altitudes and often the hours of sunshine last throughout the whole day. Hollow light-guides with very high inner specular reflectances can transport sunbeams downward into the windowless building core very effectively. Due to the tube's diameter and length and multiple reflections, complex illuminance patterns are produced on the underside of the tube, i.e. on top of the glazed ceiling aperture that illuminates the interior space or its working plane. This paper discusses several daylight conditions in tropical interiors illuminated by tubular light-guides. The recently published HOLIGILM calculation program and the user-friendly tool HOLIGILM 4.2 have facilitated the production of this paper. (author)

  17. [Primary distal renal tubular acidosis: a case report].

    Abdallah, Jihene Ben; Charfeddine, Bassem; Braham, Imen; Neffati, Souhir; Othmen, Leila Ben; Letaief, Affef; Smach, Mohamed Ali; Bourfifa, Zoheier; Dridi, Hedi; Limem, Khalifa

    2011-01-01

    The primary distal renal tubular acidosis is characterized biochemically by the inability of the kidney to produce appropriately acid urine in the presence of systemic metabolic acidosis or after acid loading (e.g. ammonium chloride). It is secondary to defective excretion of H(+) by the cells of the collecting duct. We report the observation of the child MC, 4-year-old, for whom the association of polyuria-polydipsia syndrome, a failure to thrive, nephrolithiasis, hypercalciuria, and especially a high urine pH in the presence of metabolic acidosis did evoke diagnosis of distal renal tubular acidosis. An urine acidification test with ammonium chloride was performed, the urinary pH was always higher than 5.5, thus confirming the diagnosis. PMID:21464016

  18. Dynamic model of microalgal production in tubular photobioreactors.

    Fernández, I; Acién, F G; Fernández, J M; Guzmán, J L; Magán, J J; Berenguel, M

    2012-12-01

    A dynamic model for microalgal culture is presented. The model takes into account the fluid-dynamic and mass transfer, in addition to biological phenomena, it being based on fundamental principles. The model has been calibrated and validated using data from a pilot-scale tubular photobioreactor but it can be extended to other designs. It can be used to determine, from experimental measurements, the values of characteristic parameters. The model also allows a simulation of the system's dynamic behaviour in response to solar radiation, making it a useful tool for design and operation optimization of photobioreactors. Moreover, the model permits the identification of local pH gradients, dissolved oxygen and dissolved carbon dioxide; that can damage microalgae growth. In addition, the developed model can map the different characteristic time scales of phenomena inside microalgae cultures within tubular photobioreactors, meaning it is a valuable tool in the development of advanced control strategies for microalgae cultures. PMID:23073105

  19. Acute tubular necrosis in a patient with paroxysmal nocturnal hemoglobinuria

    Eranga S Wijewickrama

    2013-01-01

    Full Text Available Acute renal failure (ARF is a well-recognized complication of paroxysmal nocturnal hemoglobinuria (PNH. The predominant mechanism is intravascular hemolysis resulting in massive hemoglobinuria ARF. We report a case of acute tubular necrosis (ATN developed in the absence of overwhelming evidence of intravascular hemolysis in a 21-year-old man with anemia, who was eventually diagnosed to have PNH. The patient presented with rapidly deteriorating renal functions in the background of iron deficiency anemia, which was attributed to reflux esophagitis. There was no clinical or laboratory evidence of intravascular hemolysis. Renal biopsy revealed ATN with deposition of hemosiderin in the proximal tubular epithelial cells. Diagnosis of PNH was confirmed with a positive Ham′s test and flow cytometry. Our case emphasizes the need to consider ATN as a possible cause for ARF in patients suspected to have PNH even in the absence of overwhelming evidence of intravascular hemolysis.

  20. Inner-tubular physicochemical processes of carbon nanotubes

    YANG Quanhong; LI Lixiang; CHENG Huiming; WANG Maozhang; BAI Jinbo

    2003-01-01

    Nanosized inner cavities of carbon nanotubes (CNTs) afford quasi-one-dimensional (1D) confined space, in which materials adsorbed or filled are of reactivity greatly different from the materials adsorbed on a planar surface and quite a number of curious physicochemical processes will possibly occur. In other words, 1D CNT nanochannels may serve as "nanosized test tubes". In this article, on the basis of the unique chemical and physical properties of CNTs, the latest progresses of the research on peculiar inner-tubular physicochemical processes of CNTs are briefly reviewed from several aspects. The extraordinary 1D adsorption, capillary filling and nanoscale-confined reaction are discussed in detail. Moreover, the characteristics of "nanosized test tubes" are summarized and many unfamiliar inner cavity chemical processes are expected. Finally, the future direction and challenges on basic researches and potential applications of inner-tubular chemistry of CNTs are discussed.

  1. Screening renal stone formers for distal renal tubular acidosis

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted......; 13 had incomplete and 1 had complete distal RTA. Distal RTA was found particularly in recurrent stone formers (17%), and especially in those with bilateral stone disease, where a distal renal tubular acidification defect was found in 50%. We have been unable to differentiate primary from secondary...... RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use in...

  2. A distal renal tubular acidosis showing hyperammonemia and hyperlactacidemia

    C. Ripoli

    2012-08-01

    Full Text Available Introduction: distal renal tubular acidosis (dRTA presents itself with variable clinical manifestations and often with late expressions that impact on prognosis. Case report: A 45-day-old male infant was admitted with stopping growth, difficult feeding and vomiting after meals. Clinical tests and labs revealed a type 1 renal tubular acidosis, even if the first blood tests showed ammonium and lactate increase. We had to exclude metabolic diseases before having a certain diagnosis. Conclusions: blood and urine investigations and genetic tests are fundamental to formulate dRTA diagnosis and to plan follow-up, according to possible phenotypic expressions of recessive and dominant autosomal forms in patients with dRTA.

  3. Tubular separate first wall for ITER-EDA

    The tubular solution first wall is the most suitable one to cope with the thermal stresses, the use of double wall reduces the risk of leaks inside the vacuum vessel by avoiding the growth of a crack through both walls: the soft brazing in between wall stops the growth of a crack from one tube to the other. The eddy currents induced in the tubes are low and the Halo current flowing poloidally in the tubes exert a radial pressure which is supported by the blanket box via ad hoc supporting points provided in between first wall and blanket. The tubes can be made of steel to resist a heat flux of up to 1 MW/m2. For higher heat loads copper or vanadium can be used. The tubular first wall can be replaced independently from the blanket. The thermo-hydraulic electro-magnetic and dynamic analysis confirm the viability of the solution proposed

  4. Tubular separate first wall for ITER-EDA

    Pizzuto, A.; Riccardi, B. [Associazione EURATOM-ENEA sulla Fusione, Frascati (Italy); Salpietro, E.; Malavasi, G. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany). NET Design Team

    1994-11-01

    The tubular solution first wall is the most suitable one to cope with the thermal stresses, the use of double wall reduces the risk of leaks inside the vacuum vessel by avoiding the growth of a crack through both walls: the soft brazing in between wall stops the growth of a crack from one tube to the other. The eddy currents induced in the tubes are low and the Halo current flowing poloidally in the tubes exert a radial pressure which is supported by the blanket box via ad hoc supporting points provided in between first wall and blanket. The tubes can be made of steel to resist a heat flux of up to 1 MW/m{sup 2}. For higher heat loads copper or vanadium can be used. The tubular first wall can be replaced independently from the blanket. The thermo-hydraulic electro-magnetic and dynamic analysis confirm the viability of the solution proposed.

  5. Intrarenal purinergic signaling in the control of renal tubular transport

    Prætorius, Helle; Leipziger, Jens Georg

    2010-01-01

    Renal tubular epithelial cells receive hormonal input that regulates volume and electrolyte homeostasis. In addition, numerous intrarenal, local signaling agonists have appeared on the stage of renal physiology. One such system is that of intrarenal purinergic signaling. This system involves all ...... of NaCl at the macula densa. This review describes the relevant aspects of local, intrarenal purinergic signaling and outlines its integrative concepts....

  6. Renal tubular acidosis secondary to jejunoileal bypass for morbid obesity

    Schaffalitzky de Muckadell, O B; Ladefoged, Jens; Thorup, Jørgen Mogens

    1985-01-01

    Renal handling of acid and base was studied in patients with persistent metabolic acidosis 3-9 years after jejunoileal bypass for morbid obesity. Excretion of acid was studied before and after intravenous infusion of NH4Cl and excretion of bicarbonate after infusion of NaHCO3. Bypass patients...... groups. Fractional loss of bicarbonate in urine was higher in controls than in bypass patients. The renal impairment is classified as distal renal tubular acidosis....

  7. Electrolytic-Plasma Treatment of Inner Surface of Tubular Products

    Yu. G. Alekseev; A. Yu. Korolyov; V. S. Niss; A. E. Parshuta

    2016-01-01

    While manufacturing a number of important tubular products stringent requirements have been imposed on quality of their inner surfaces. The well-known methods for inner surface treatment of pipes include sandblasting, chemical cleaning with acid reagents (oxalic, formic, sulfamic, orthophosphoric acids) and electrochemical polishing. Disadvantages of the chemical method are cleaning-up irregularities, high metal removal, limited number of reagent application, complicated selection of reagent ...

  8. Stator iron loss of tubular permanent-magnet machines

    Amara, Y; Wang, J B; Howe, D

    2005-01-01

    While methods of determining the iron loss in rotating permanent-magnet (PM) machines have been investigated extensively, the study of iron loss in linear machines is relatively poorly documented. This paper describes a simple analytical method to predict flux density waveforms in discrete regions of the laminated stator of a tubular PM machine, and employs an established iron loss model to determine the iron loss components, on both no load and on load. Analytical predictions are compared wi...

  9. Optimal startup control of a jacketed tubular reactor.

    Hahn, D. R.; Fan, L. T.; Hwang, C. L.

    1971-01-01

    The optimal startup policy of a jacketed tubular reactor, in which a first-order, reversible, exothermic reaction takes place, is presented. A distributed maximum principle is presented for determining weak necessary conditions for optimality of a diffusional distributed parameter system. A numerical technique is developed for practical implementation of the distributed maximum principle. This involves the sequential solution of the state and adjoint equations, in conjunction with a functional gradient technique for iteratively improving the control function.

  10. Distal renal tubular acidosis and amelogenesis imperfecta: A rare association

    Ravi, P.; Ekambaranath, T. S.; Arasi, S. Ellil; Fernando, E.

    2013-01-01

    Renal tubular acidosis (RTA) is characterized by a normal anion gap with hyperchloremic metabolic acidosis. Primary distal RTA (type I) is the most common RTA in children. Childhood presentation of distal RTA includes vomiting, failure to thrive, metabolic acidosis, and hypokalemia. Amelogenesis imperfecta (AI) represents a condition where the dental enamel and oral tissues are affected in an equal manner resulting in the hypoplastic or hypopigmented teeth. We report a 10-year-old girl, previ...

  11. Study of maximum pressure for composite hepta-tubular powders

    M. C. Gupta

    1959-10-01

    Full Text Available In this paper the expressions for maximum pressure occurring positions in the case of composite hepta-tubular powers used in conventional guns and the corresponding conditions have been derived under certain conditions, viz., the value of n, the ratio of specific heats, has been assumed to be the same for both the charges and the covolume corrections have not been neglected.

  12. CHARACTERISTICS OF CORN STALK HEMICELLULOSE PYROLYSIS IN A TUBULAR REACTOR

    Gao-Jin Lv; Shu-Bin Wu; Rui Lou

    2010-01-01

    Pyrolysis characteristics of corn stalk hemicellulose were investigated in a tubular reactor at different temperatures, with focus mainly on the releasing profiles and forming behaviors of pyrolysis products (gas, char, and tar). The products obtained were further identified using various approaches (including GC, SEM, and GC-MS) to understand the influence of temperature on product properties and compositions. It was found that the devolatilization of hemicellulose mainly occurred at low tem...

  13. CT diagnosis of intramedulear lesions of the tubular bone

    Three cases are used to demonstrate that intramedullary masses of the tubular bones can be discovered using computered tomography even when changes in the plain film are lacking or discrete. However, it was not possible to differentiate between osteomyelitis, chondrosarcoma and enchondroma owing to the identical morphology of these three diseases. Consequently, CT does not allow any statement on type and dignity and histological clarification is indispensable. (orig./WU)

  14. Tubular biomarkers to assess progression of diabetic nephropathy.

    Tramonti, Gianfranco; Kanwar, Yashpal S

    2011-05-01

    Despite aggressive management, many patients with diabetic nephropathy still develop end-stage renal disease. Accompanying tubulointerstitial damage is important in the progression of diabetic nephropathy. Markers of tubular damage, such as NGAL, KIM-1, and LFABP, have been proposed for monitoring the effectiveness of therapy. However, Nielsen et al. report a lack of an independent correlation between these biomarkers and glomerular filtration rate. Therefore, these markers seem to offer no improvement in the management of diabetic nephropathy. PMID:21527942

  15. ELECTROLYTIC-PLASMA TREATMENT OF INNER SURFACE OF TUBULAR PRODUCTS

    Yu. G. Alekseev

    2016-01-01

    Full Text Available While manufacturing a number of important tubular products stringent requirements have been imposed on quality of their inner surfaces. The well-known methods for inner surface treatment of pipes include sandblasting, chemical cleaning with acid reagents (oxalic, formic, sulfamic, orthophosphoric acids and electrochemical polishing. Disadvantages of the chemical method are cleaning-up irregularities, high metal removal, limited number of reagent application, complicated selection of reagent chemical composition and concentration, complicated and environmentally harmful recycling of waste chemicals, high cost of reagents. Low productivity at a high cost, as well as hazardous impact on personnel due to high dispersion of abrasive dust are considered as disadvantages of sandblasting. Electrochemical polishing is characterized by the following disadvantages: low processing productivity because supply of high currents is rather difficult due to electrolyte scattering capacity away from the main electrode action zone, limited length of the cavity to be treated due to heating of flexible current leads at operating current densities, application of expensive aggressive electrolytes and high costs of their recycling. A new method for polishing and cleaning of inner surfaces of tubular products based on electrolyte-plasma treatment has been developed. In comparison with the existing methods the proposed methods ensures quality processing with high intensity while applying non-toxic, environmentally friendly and cheap electrolytes. The paper presents results of investigations on technological specific features of electrolyte-plasma treatment for inner surfaces of tubular products: influence of slotted nozzle width, electrolyte flow and rate on stability of gas-vapor blanket, current density and productivity. Results of the research have made it possible to determine modes that provide stability and high productivity in the process of electrolyte

  16. Fatigue behaviour and detailing of slotted tubular connection

    Pereira Baptista, Claudio Alexandre; Borges, Luis; Yadav, Santosh; NUSSBAUMER, Alain

    2015-01-01

    Tubular elements are used in steel structures not only for bracing of other members but also as cross girders diaphragms. They are a competitive solution both due to the lightweight and structural efficiency. Slotted tube-to-plate connections are the natural and most common choice. However, fatigue design of the abrupt transition and differences in the stiffness corresponding to the welded connection, is a critical part of the design. Although such a fatigue connection is classified in differ...

  17. Characterisitics of Streptomyces griseus biofilms in continuous flow tubular reactors

    Winn, Michael; Habimana, Olivier; Casey, Eoin; Murphy, Cormac D.

    2014-01-01

    The purpose of this study was to investigate the feasibility of cultivating the biotechnologically important bacterium Streptomyces griseus in single-species and mixed- species biofilms using a Tubular Biofilm Reactor (TBR). Streptomyces griseus biofilm development was found to be cyclical, starting with the initial adhesion and subsequent development of a visible biofilm after 24 hours growth, followed by the complete detachment of the biofilm as a single mass, and ending with the re-coloni...

  18. Elastomer liners for geothermal tubulars Y267 EPDM Liner Program:

    Hirasuna, A.R.; Davis, D.L.; Flickinger, J.E.; Stephens, C.A.

    1987-12-01

    The elastomer, Y267 EPDM, has been identified as a hydrothermally stable material which can operate at temperatures in excess of 320/sup 0/C. The goal of the Y267 Liner Program was to demonstrate the feasibility of using this material as a liner for mild steel tubulars to prevent or mitigate corrosion. If successful, the usage of EPDM lined pipe by the geothermal community may have a significant impact on operating costs and serve as a viable alternative to the use of alloyed tubulars. Tooling procedures were developed under this program to mold a 0.64 cm (0.25'') thick Y267 EPDM liner into a tubular test section 61 cm (2') in length and 19.1 cm (7.5'') in diameter (ID). A successful effort was made to identify a potential coupling agent to be used to bond the elastomer to the steel tubular wall. This agent was found to withstand the processing conditions associated with curing the elastomer at 288/sup 0/C and to retain a significant level of adhesive strength following hydrothermal testing in a synthetic brine at 260/sup 0/C for a period of 166 hours. Bonding tests were conducted on specimens of mild carbon steel and several alloys including Hastelloy C-276. An objective of the program was to field test the lined section of pipe mentioned above at a geothermal facility in the Imperial Valley. Though a test was conducted, problems encountered during the lining operation precluded an encouraging outcome. The results of the field demonstration were inconclusive. 6 refs., 13 figs., 13 tabs

  19. Load introduction into concrete-filled steel tubular columns

    Mollazadeh, Mohammad Hassan

    2015-01-01

    Concrete-Filled Steel Tubular (CFST) columns are increasingly being used because of their many advantages, including high strength, high ductility, and higher fire resistance than conventional steel or concrete columns of the same size. In order to maximise the advantages of CFST column, composite action of the column should be ensured. In realistic structures, the load is not directly applied to the entire CFST column section and is introduced from the beam-column connection. Simple shear c...

  20. Berberine activates Nrf2 nuclear translocation and inhibits apoptosis induced by high glucose in renal tubular epithelial cells through a phosphatidylinositol 3-kinase/Akt-dependent mechanism.

    Zhang, Xiuli; Liang, Dan; Lian, Xu; Jiang, Yan; He, Hui; Liang, Wei; Zhao, Yue; Chi, Zhi-Hong

    2016-06-01

    Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Berberine (BBR) is identified as a potential anti-diabetic herbal medicine due to its beneficial effects on insulin sensitivity, glucose metabolism and glycolysis. In this study, the underlying mechanisms involved in the protective effects of BBR on high glucose-induced apoptosis were explored using cultured renal tubular epithelial cells (NRK-52E cells) and human kidney proximal tubular cell line (HK-2 cells). We identified the pivotal role of phosphatidylinositol 3-kinase (PI3K)/Akt in BBR cellular defense mechanisms and revealed the novel effect of BBR on nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and heme oxygenase (HO)-1 in NRK-52E and HK-2 cells. BBR attenuated reactive oxygen species production, antioxidant defense (GSH and SOD) and oxidant-sensitive proteins (Nrf2 and HO-1), which also were blocked by LY294002 (an inhibitor of PI3K) in HG-treated NRK-52E and HK-2 cells. Furthermore, BBR improved mitochondrial function by increasing mitochondrial membrane potential. BBR-induced anti-apoptotic function was demonstrated by decreasing apoptotic proteins (cytochrome c, Bax, caspase3 and caspase9). All these findings suggest that BBR exerts the anti-apoptosis effects through activation of PI3K/Akt signal pathways and leads to activation of Nrf2 and induction of Nrf2 target genes, and consequently protecting the renal tubular epithelial cells from HG-induced apoptosis. PMID:26979714

  1. A Tubular Biomaterial Construct Exhibiting a Negative Poisson's Ratio.

    Jin Woo Lee

    Full Text Available Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson's ratio νxy (NPR. NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson's ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts.

  2. A Tubular Biomaterial Construct Exhibiting a Negative Poisson's Ratio.

    Lee, Jin Woo; Soman, Pranav; Park, Jeong Hun; Chen, Shaochen; Cho, Dong-Woo

    2016-01-01

    Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson's ratio νxy (NPR). NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene) glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson's ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts. PMID:27232181

  3. The rebirth of interest in renal tubular function.

    Lowenstein, Jerome; Grantham, Jared J

    2016-06-01

    The measurement of glomerular filtration rate by the clearance of inulin or creatinine has evolved over the past 50 years into an estimated value based solely on plasma creatinine concentration. We have examined some of the misconceptions and misunderstandings of the classification of renal disease and its course, which have followed this evolution. Furthermore, renal plasma flow and tubular function, which in the past were estimated by the clearance of the exogenous aryl amine, para-aminohippurate, are no longer measured. Over the past decade, studies in experimental animals with reduced nephron mass and in patients with reduced renal function have identified small gut-derived, protein-bound uremic retention solutes ("uremic toxins") that are poorly filtered but are secreted into the lumen by organic anion transporters (OATs) in the proximal renal tubule. These are not effectively removed by conventional hemodialysis or peritoneal dialysis. Residual renal function, urine produced in patients with advanced renal failure or undergoing dialysis treatment, may represent, at least in part, secretion of fluid and uremic toxins, such as indoxyl sulfate, mediated by proximal tubule OATs and might serve as a useful survival function. In light of this new evidence of the physiological role of proximal tubule OATs, we suggest that measurement of renal tubular function and renal plasma flow may be of considerable value in understanding and managing chronic kidney disease. Data obtained in normal subjects indicate that renal plasma flow and renal tubular function might be measured by the clearance of the endogenous aryl amine, hippurate. PMID:26936872

  4. Tubular transport and metabolism of cimetidine in chicken kidneys

    Renal tubular transport and renal metabolism of [14C]cimetidine (CIM) were investigated by unilateral infusion into the renal portal circulation in chickens (Sperber technique). [14C]CIM was actively transported at a rate 88% that of simultaneously infused p-aminohippuric acid, and its transport was saturable. The following organic cations competitively inhibited the tubular transport of [14C]CIM with decreasing potency: CIM, ranitidine, thiamine, procainamide, guanidine and choline. CIM inhibited the transport of [14C]thiamine, [14C]amiloride and [14C]tetraethylammonium. During CIM infusion, two renal metabolites, CIM sulfoxide and hydroxymethylcimetidine, were found in urine. When CIM sulfoxide was infused, its transport efficiency was 32% and not saturable. CIM sulfoxide did ot inhibit the simultaneous renal tubular transport of p-aminohippuric acid or tetraethylammonium. CIM is transported by the organic cation transport system and the kidney metabolizes CIM. Transport of CIM and other cationic drugs could produce a drug interaction to alter drug excretion

  5. Anodic Aluminum Oxide Membrane-Assisted Fabrication of β-In2S3Nanowires

    Chen Chih-Jung

    2009-01-01

    Full Text Available Abstract In this study, β-In2S3nanowires were first synthesized by sulfurizing the pure Indium (In nanowires in an AAO membrane. As FE-SEM results, β-In2S3nanowires are highly ordered, arranged tightly corresponding to the high porosity of the AAO membrane used. The diameter of the β-In2S3nanowires is about 60 nm with the length of about 6–8 μm. Moreover, the aspect ratio of β-In2S3nanowires is up to 117. An EDS analysis revealed the β-In2S3nanowires with an atomic ratio of nearly S/In = 1.5. X-ray diffraction and corresponding selected area electron diffraction patterns demonstrated that the β-In2S3nanowire is tetragonal polycrystalline. The direct band gap energy (Eg is 2.40 eV from the optical measurement, and it is reasonable with literature.

  6. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    Carl R. Evenson; Anthony F. Sammells; Richard T. Treglio; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Clive Brereton; Warren Wolfs; James Lockhart

    2004-10-21

    During this quarter, work was focused on characterizing the stability of layered composite membranes in a one hundred percent permeate environment. Permeation data was also collected on cermets as a function of thickness. A thin film deposition procedure was used to deposit dense thin BCY/Ni onto a tubular porous support. Thin film tubes were then tested for permeation at ambient pressure. Process flow diagrams were prepared for inclusion of hydrogen separation membranes into IGCC power plants under varying conditions. Finally, membrane promoted alkane dehydrogenation experiments were performed.

  7. Synthesis of mono- and bi-layer MFI zeolite films on macroporous alumina tubular supports: Application to nanofiltration

    Said, Ali; Limousy, Lionel; Nouali, Habiba; Michelin, Laure; Halawani, Jalal; Toufaily, Joumana; Hamieh, Tayssir; Dutournié, Patrick; Daou, T. Jean

    2015-10-01

    This work is dedicated to the development of MFI-type structure zeolite films (single-layer or bilayer) on the internal layer of a specific macroporous alumina tubular support for nanofiltration applications. The bottom MFI layer was obtained by direct hydrothermal synthesis while a secondary growth method was used for the top MFI layer. A complete characterization of the obtained MFI membranes (single-layer or bilayer) is proposed using various techniques, such as X-ray diffraction, scanning electron microscopy, mercury porosimetry and nitrogen sorption measurements. Dense and highly crystallized films of MFI-type structure zeolite were obtained for both single-layer and bilayer MFI films. The total film thickness were around 7.1±0.5 μm and 14.5±1 μm for single-layer and bilayer MFI films respectively. The Si/Al molar ratio of the MFI films varied between 185 and 305 for single-layer and bilayer MFI films respectively. The hydraulic permeability of the tubular MFI membrane was achieved by the filtration of pure water. The hydraulic permeability of the single-layer and bilayer MFI membranes decreased rapidly at the beginning of the conditioning process, and stabilized at 1.08×10-14 m3 m-2 and 1.02×10-15 m3 m-2 after 15 h and the rejection rates of neutral solute (Vb 12) are 10% and 50% for the single-layer and bilayer MFI films respectively.

  8. Towards application of palladium membrane reactors in large scale production of hydrogen

    Delft, Y.C.; Saric, M.; Overbeek, J.P.; De Groot, A.; Dijkstra, J.W.; Jansen, D. [ECN Hydrogen and Clean Fossil Fuels, Petten (Netherlands)

    2009-12-15

    Palladium membrane reactors have been identified as a promising option for hydrogen production in future power production systems and industrial chemical production processes. Dense tubular Pd alloy membranes with a high hydrogen permeance have been made on ceramic supports with electroless plating on a 1m{sup 2} scale. Application of a Pd membrane and a commercial catalyst in membrane reactor experiments have shown that it is possible to shift the methane conversion beyond chemical equilibrium by means of hydrogen withdrawal. A computer model of the palladium membrane reformer was developed and has been successfully used to evaluate the impact of main operating and design parameters on the reactor performance.

  9. The molecular interactions between filtered proteins and proximal tubular cells in proteinuria.

    Baines, Richard J; Brunskill, Nigel J

    2008-01-01

    Proteinuria is associated with progressive chronic kidney disease and poor cardiovascular outcomes. Exposure of proximal tubular epithelial cells to excess proteins leads to the development of proteinuric nephropathy with tubular atrophy, interstitial inflammation and scarring. Numerous signalling pathways are activated in proximal tubular epithelial cells under proteinuric conditions resulting in gene transcription, altered growth and the secretion of inflammatory and profibrotic mediators. Megalin, the proximal tubular scavenger receptor for filtered macromolecules, has intrinsic signalling functions and may also link albumin to growth factor receptor signalling via regulated intramembrane proteolysis. It now seems that endocytosis is not always a prerequisite for albumin-evoked alterations in proximal tubular cell phenotype. Recent evidence shows the presence of other potential receptors for proteins, such as the neonatal Fc receptor and CD36, in the proximal tubular epithelium. PMID:18849618

  10. Method and tool for contracting tubular members by electro-hydraulic forming before hydroforming

    Golovashchenko, Sergey Fedorovich

    2011-03-15

    A tubular preform is contracted in an electro-hydraulic forming operation. The tubular preform is wrapped with one or more coils of wire and placed in a chamber of an electro-hydraulic forming tool. The electro-hydraulic forming tool is discharged to form a compressed area on a portion of the tube. The tube is then placed in a hydroforming tool that expands the tubular preform to form a part.

  11. Inverse Approach to Evaluate the Tubular Material Parameters Using the Bulging Test

    Yulong Ge; Xiaoxing Li; Lihui Lang

    2015-01-01

    Tubular material parameters are required for both part manufactory process planning and finite element simulations. The bulging test is one of the most credible ways to detect the property parameters for tubular material. The inverse approach provides more effective access to the accurate material evaluation than with direct identifications. In this paper, a newly designed set of bulging test tools is introduced. An inverse procedure is adopted to determine the tubular material properties in ...

  12. Generation of Urinary Albumin Fragments Does Not Require Proximal Tubular Uptake

    Weyer, K.; Nielsen, R; Christensen, E.I.; Birn, H

    2012-01-01

    Urinary albumin excretion is an important diagnostic and prognostic marker of renal function. Both animal and human urine contain large amounts of albumin fragments, but whether these fragments originate from renal tubular degradation of filtered albumin is unknown. Here, we used mice with kidneys lacking megalin and cubilin, the coreceptors that mediate proximal tubular endocytosis of albumin, to determine whether proximal tubular degradation of albumin forms the detectable urinary albumin f...

  13. A tubular segmented-flow bioreactor for the infection of insect cells with recombinant baculovirus

    Hu, Yu-Chen; Wang, Ming-Ying; Bentley, William E.

    1997-01-01

    A continuous process of insect cell (S f9) growth and baculovirus infection is tested with the sequential combination of a CSTR and a tubular reactor. A tubular infection reactor enables continuous introduction of baculovirus and therefore avoids the ‘passage effect’ observed in two-stage CSTR systems. Moreover, a tubular reactor can be used to test cell infection kinetics and the subsequent metabolism of infected insect cells. Unlike batch and CSTR culture, cells in a horizontally positioned...

  14. A CFD analysis of transport phenomena and electrochemical reactions in a tubular-shaped PEM fuel cell

    Maher A.R. Sadiq Al-Baghdadi

    2013-01-01

    Full Text Available A fuel cell is most interesting new power source because it solves not only the environment problem but also natural resource exhaustion problem. CFD modeling and simulation for heat and mass transport in PEM fuel cells are being used extensively in researches and industrial applications to gain better understanding of the fundamental processes and to optimize fuel cell designs before building a prototype for engineering application. In this research, full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM fuel cell has been developed. This comprehensive model accounts for the major transport phenomena such as convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields in a tubular-shaped PEM fuel cell. The model explains many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analysed, with the focus on the physical insight and fundamental understanding.

  15. A CFD analysis of transport phenomena and electrochemical reactions in a tubular-shaped PEM fuel cell

    Sadiq Al-Baghdadi, Maher A.R. [Fuel Cell Research Center, International Energy and Environment Foundation, Al-Najaf, P.O.Box 39 (Iraq)

    2013-07-01

    A fuel cell is most interesting new power source because it solves not only the environment problem but also natural resource exhaustion problem. CFD modeling and simulation for heat and mass transport in PEM fuel cells are being used extensively in researches and industrial applications to gain better understanding of the fundamental processes and to optimize fuel cell designs before building a prototype for engineering application. In this research, full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena such as convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields in a tubular-shaped PEM fuel cell. The model explains many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analysed, with the focus on the physical insight and fundamental understanding.

  16. High temperature fatigue experiments on welded stainless steel tubular elements

    A test rig has been designed to perform high temperature fatigue experiments on AISI 304 stainless steel tubular elements of 500 mm length, 60.3 mm outer diameter and 2 mm thickness; they are composed by two butt welded tubular elements with welded end flanges. During the experiments it is possible to control the axial strain range, the strain rate and the hold time; the specimen temperature is obtained by an inner heating device, controlled by a series of measuring thermocouples; until now the imposed temperature is 6500C. A preliminary series of experiments has been carried out, with the aim at getting informations for a proper development of the main experimental program, while in the meantime the adjustment of the specimen manufacturing process and its characterization have been performed. Each specimen is welded on the same TIG welding rig, which accounts both for a uniformly reliable welding process and for a proper alignment of the tubular elements. The specimens are then marked by a high precision grid which allows a measurement of the residual localized plastic strain along some generatrix of the specimen and on its thickness. The basic fatigue data have to be measured through a series of standard tests carried out on small size specimens obtained either from the base material and around the welded, heat affected zone. It is also planned to carry out a detailed study on the crack surfaces and to use acoustical emission techniques to properly assess the initial crack propagation. The first results show a marked reduction of the number of cycles at failure, if compared with existing data about small size specimens; the measurement of residual plastic strains shows clearly non-uniform distribution of the plastic zones

  17. High temperature helical tubular receiver for concentrating solar power system

    Hossain, Nazmul

    In the field of conventional cleaner power generation technology, concentrating solar power systems have introduced remarkable opportunity. In a solar power tower, solar energy concentrated by the heliostats at a single point produces very high temperature. Falling solid particles or heat transfer fluid passing through that high temperature region absorbs heat to generate electricity. Increasing the residence time will result in more heat gain and increase efficiency. A novel design of solar receiver for both fluid and solid particle is approached in this paper which can increase residence time resulting in higher temperature gain in one cycle compared to conventional receivers. The helical tubular solar receiver placed at the focused sunlight region meets the higher outlet temperature and efficiency. A vertical tubular receiver is modeled and analyzed for single phase flow with molten salt as heat transfer fluid and alloy625 as heat transfer material. The result is compared to a journal paper of similar numerical and experimental setup for validating our modeling. New types of helical tubular solar receivers are modeled and analyzed with heat transfer fluid turbulent flow in single phase, and granular particle and air plug flow in multiphase to observe the temperature rise in one cyclic operation. The Discrete Ordinate radiation model is used for numerical analysis with simulation software Ansys Fluent 15.0. The Eulerian granular multiphase model is used for multiphase flow. Applying the same modeling parameters and boundary conditions, the results of vertical and helical receivers are compared. With a helical receiver, higher temperature gain of heat transfer fluid is achieved in one cycle for both single phase and multiphase flow compared to the vertical receiver. Performance is also observed by varying dimension of helical receiver.

  18. The role of duplex stainless steels for downhole tubulars

    In sour conditions there is an increasing trend to turn to corrosion resistant alloys for downhole tubulars. The most commonly used CRA tubular is 13Cr, and there are thousands of feet in service. However, there are limits to the use of 13Cr, ie., the risk of sulphide stress corrosion cracking at high H2S levels, and the possibility of pitting or high corrosion rates in waters with high chloride contents. Where the service conditions are felt to be too severe for 13Cr alloys it has been traditional to switch to nickel base alloys such as alloys 825 and C-276 (UNS N08825 and N10276). The alloys are much more expensive than 13Cr, and in recent years the duplex stainless steels have been selected as alloys with superior corrosion and SSCC resistance compared with 13Cr, and having lower cost than nickel alloys. Originally the 22Cr duplex alloy (UNS 31803) was used, but more recently the 25Cr super duplex alloys (UNS S32760 and S32750) have become more available. The present paper reviews the data available for 13Cr and the limits of applicability. Data is also presented for laboratory tests for both the 22Cr and 25Cr super duplex alloys. There is extensive service experience with both 22Cr and 25Cr super duplex in the North Sea, covering both downhole tubulars, manifold and post wellhead equipment. Data is presented showing some of the sour condition being experienced in the North Sea by super duplex alloys. These results show that there is a substantial gap between the limits of use for 13Cr and the 25Cr super duplex stainless steel alloys. This means that in many sour environments super duplex stainless steel provides a cost effective alternative to nickel-base alloys

  19. Superradiance at the localization-delocalization crossover in tubular chlorosomes

    Molina, Rafael A; Somoza, Alejandro; Chen, Lipeng; Zhao, Yang

    2016-01-01

    We study the effect of disorder on spectral properties of tubular chlorosomes in green sulfur bacteria Cf. aurantiacus. Employing a Frenkel-exciton Hamiltonian with diagonal and off-diagonal disorder consistent with spectral and structural studies, we analyze excitonic localization and spectral statistics of the chlorosomes. A size-dependent localization-delocalization crossover is found to occur as a function of the excitonic energy. The crossover energy region coincides with the more optically active states with maximized superradiance, and is, consequently, more conducive for energy transfer.

  20. On the volume of tubular neighbourhoods of real algebraic varieties

    Martin Lotz

    2012-01-01

    The problem of determining the volume of a tubular neighbourhood has a long and rich history. Bounds on the volume of neighbourhoods of algebraic sets have turned out to play an important role in the probabilistic analysis of condition numbers in numerical analysis. We present a self-contained derivation of bounds on the probability that a random point, chosen uniformly from a ball, lies within a given distance of a real algebraic variety of any codimension. The bounds are given in terms of t...

  1. Distal renal tubular acidosis and amelogenesis imperfecta: A rare association.

    Ravi, P; Ekambaranath, T S; Arasi, S Ellil; Fernando, E

    2013-11-01

    Renal tubular acidosis (RTA) is characterized by a normal anion gap with hyperchloremic metabolic acidosis. Primary distal RTA (type I) is the most common RTA in children. Childhood presentation of distal RTA includes vomiting, failure to thrive, metabolic acidosis, and hypokalemia. Amelogenesis imperfecta (AI) represents a condition where the dental enamel and oral tissues are affected in an equal manner resulting in the hypoplastic or hypopigmented teeth. We report a 10-year-old girl, previously asymptomatic presented with the hypokalemic paralysis and on work-up found out to have type I RTA. The discoloration of teeth and enamel was diagnosed as AI. PMID:24339526

  2. A Tubular Ionizer as an Efficient Negative Fluorine Ion Source

    In order to establish the optimal conditions of F- ion production by the tubular ionizer extensive studies of SF6 ionization using the mass separator were performed. The SF6, SF5, SF4, SF3 and F negative ions were observed, and the F- yields as a function of the source temperature, gas pressure and an amount of alkaline metal vapors (K, Na, Ca, Sr, Ba) were measured. The efficiency of F- production of about 40 obtained for the optimal conditions. The delay time and adsorption enthalpy of fluorine on the tantalum surface has been measured for the first time. (author)

  3. Use of graphite layer open tubular (GLOT) in environmental analysis

    Recently it has been developed a series of new capillary columns characterised by the use of graphitized carbon black modified from different amount of liquid phase. The characteristics of these columns, called graphite layer open tubular (GLOT), are described together with their application to the environmental analysis. A specific application of GLOT columns is for the direct analysis of aqueous solutions avoiding solvent extraction procedure. A comparison between a GLOT column and a traditional capillary column, estimating their behaviour after repeated direct injections of aqueous solution sample is written. Some applications regarding the analysis of the atmosphere pollutants, as aliphatic and aromatic hydrocarbons, and their compounds are written too

  4. Type 4 renal tubular acidosis in a kidney transplant recipient.

    Kulkarni, Manjunath

    2016-02-01

    We report a case of a 66-year-old diabetic patient who presented with muscle weakness 2 weeks after kidney transplantation. Her immunosuppressive regimen included tacrolimus, mycophenolate mofetil, and steroids. She was found to have hyperkalemia and normal anion gap metabolic acidosis. Tacrolimus levels were in therapeutic range. All other drugs such as beta blockers and trimethoprim - sulfamethoxazole were stopped. She did not respond to routine antikalemic measures. Further evaluation revealed type 4 renal tubular acidosis. Serum potassium levels returned to normal after starting sodium bicarbonate and fludrocortisone therapy. Though hyperkalemia is common in kidney transplant recipients, determining exact cause can guide specific treatment. PMID:27105603

  5. Tubular algebras and affine Kac-Moody algebras

    Zheng-xin CHEN; Ya-nan LIN

    2007-01-01

    The purpose of this paper is to construct quotient algebras L(A)C1/I(A) of complex degenerate composition Lie algebras L(A)C1 by some ideals, where L(A)C1 is defined via Hall algebras of tubular algebras A, and to prove that the quotient algebras L(A)C1/I(A) are isomorphic to the corresponding affine Kac-Moody algebras. Moreover, it is shown that the Lie algebra Lre(A)C1 generated by A-modules with a real root coincides with the degenerate composition Lie algebra L(A)C1 generated by simple A-modules.

  6. Tubular algebras and affine Kac-Moody algebras

    2007-01-01

    The purpose of this paper is to construct quotient algebras L(A)1C/I(A) of complex degenerate composition Lie algebras L(A)1C by some ideals, where L(A)1C is defined via Hall algebras of tubular algebras A, and to prove that the quotient algebras L(A)1C/I(A) are isomorphic to the corresponding affine Kac-Moody algebras. Moreover, it is shown that the Lie algebra Lre(A)1C generated by A-modules with a real root coincides with the degenerate composition Lie algebra L(A)1C generated by simple A-modules.

  7. The role of cholesterol-sphingomyelin membrane nanodomains in the stability of intercellular membrane nanotubes

    Veranič P

    2012-04-01

    Full Text Available Maruša Lokar1,*, Doron Kabaso1,2,*, Nataša Resnik3, Kristina Sepcic5, Veronika Kralj-Iglic4,6, Peter Veranic3, Robert Zorec2, Aleš Iglic1,6 1Laboratory of Biophysics, Faculty of Electrical Engineering, 2Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, 3Institute of Cell Biology, Faculty of Medicine, 4Faculty of Health Sciences, 5Department of Biology, Biotechnical Faculty, 6Laboratory of Clinical Biophysics, Department of Orthopedic Surgery, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia*These authors equally share first authorshipAbstract: Intercellular membrane nanotubes (ICNs are highly curved tubular structures that connect neighboring cells. The stability of these structures depends on the inner cytoskeleton and the cell membrane composition. Yet, due to the difficulty in the extraction of ICNs, the cell membrane composition remains elusive. In the present study, a raft marker, ostreolysin, revealed the enrichment of cholesterol-sphingomyelin membrane nanodomains along ICNs in a T24 (malignant urothelial cancer cell line. Cholesterol depletion, due to the addition of methyl-β-cyclodextrin, caused the dispersion of cholesterol-sphingomyelin membrane nanodomains and the retraction of ICNs. The depletion of cholesterol also led to cytoskeleton reorganization and to formation of actin stress fibers. Live cell imaging data revealed the possible functional coupling between the change from polygonal to spherical shape, cell separation, and the disconnection of ICNs. The ICN was modeled as an axisymmetric tubular structure, enabling us to investigate the effects of cholesterol content on the ICN curvature. The removal of cholesterol was predicted to reduce the positive spontaneous curvature of the remaining membrane components, increasing their curvature mismatch with the tube curvature. The mechanisms by which the increased curvature mismatch could contribute to the disconnection of ICNs are

  8. Membrane Biophysics

    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.

  9. Facile fabrication of freestanding through-hole ZrO2 nanotube membranes via two-step anodization methods

    Highly ordered freestanding tubular zirconia (ZrO2) membrane was prepared via an electrochemical anodization of zirconium (Zr) substrate in non-aqueous electrolytes (mixture of formamide and glycerol (weight ratio 1:1) containing 1 wt% NH4F and 3 wt% H2O). Two methods were used to fabricate the two-end opened ZrO2 membranes, one is a potential shock method and another is a reducing potential method. The two-end opened ZrO2 membrane was produced through the detachment of the existing self-organized ZrO2 tubular layer from Zr substrate or sub tubular layer. The microstructures and morphologies of the samples were studied by scanning electron microscopy and the growth mechanisms of the two-end opened ZrO2 nanotube arrays were investigated.

  10. Modeling of an immobilized lipase tubular reactor for the production of glycerol and fatty acids from oils; Modelado de un reactor tubular de lipasas inmovilizadas para la produccion de glicerol y acidos grasos a partir de aceites

    Oddone, S.; Grasselli, M.; Cuellas, A.

    2010-07-01

    Advances in the design of a bioreactor in the fats and oils industry have permitted the hydrolysis of triglycerides in mild conditions and improved productivity while avoiding the formation of unwanted byproducts. The present work develops a mathematical model that describes the hydrolytic activity of a tubular reactor with immobilized lipases for the production of glycerol and fatty acids from the oil trade. Runge Kuttas numerical method of high order has been applied, considering that there is no accumulation of the substratum in the surface of the membrane, where the enzyme is. At the same time, different equations based on the kinetic model of Michaelis Mentens and the Ping-Pong bi-bi mechanism were examined. Experimental data in discontinuous systems are the basis for the development of the quantitative mathematical model that was used to simulate the process computationally. The obtained results allow for optimizing both the operative variables and the economic aspects of industrial processes. (Author)

  11. Molecular Dynamics Study of Carbon Nanotubes/Polyamide Reverse Osmosis Membranes: Polymerization, Structure, and Hydration.

    Araki, Takumi; Cruz-Silva, Rodolfo; Tejima, Syogo; Takeuchi, Kenji; Hayashi, Takuya; Inukai, Shigeki; Noguchi, Toru; Tanioka, Akihiko; Kawaguchi, Takeyuki; Terrones, Mauricio; Endo, Morinobu

    2015-11-11

    Carbon nanotubes/polyamide (PA) nanocomposite thin films have become very attractive as reverse osmosis (RO) membranes. In this work, we used molecular dynamics to simulate the influence of single walled carbon nanotubes (SWCNTs) in the polyamide molecular structure as a model case of a carbon nanotubes/polyamide nanocomposite RO membrane. It was found that the addition of SWCNTs decreases the pore size of the composite membrane and increases the Na and Cl ion rejection. Analysis of the radial distribution function of water confined in the pores of the membranes shows that SWCNT+PA nanocomposite membranes also exhibit smaller clusters of water molecules within the membrane, thus suggesting a dense membrane structure (SWCNT+PA composite membranes were 3.9% denser than bare PA). The results provide new insights into the fabrication of novel membranes reinforced with tubular structures for enhanced desalination performance. PMID:26505521

  12. Regulated Degradation of an Endoplasmic Reticulum Membrane Protein in a Tubular Lysosome in Leishmania mexicana

    Mullin, Kylie A.; Foth, Bernardo J.; Ilgoutz, Steven C.; Callaghan, Judy M.; Zawadzki, Jody L.; McFadden, Geoffrey I; McConville, Malcolm J.

    2001-01-01

    The cell surface of the human parasite Leishmania mexicana is coated with glycosylphosphatidylinositol (GPI)-anchored macromolecules and free GPI glycolipids. We have investigated the intracellular trafficking of green fluorescent protein- and hemagglutinin-tagged forms of dolichol-phosphate-mannose synthase (DPMS), a key enzyme in GPI biosynthesis in L. mexicana promastigotes. These functionally active chimeras are found in the same subcompartment of the endop...

  13. Toxicological significance of renal Bcrp: Another potential transporter in the elimination of mercuric ions from proximal tubular cells

    Secretion of inorganic mercury (Hg2+) from proximal tubular cells into the tubular lumen has been shown to involve the multidrug resistance-associated protein 2 (Mrp2). Considering similarities in localization and substrate specificity between Mrp2 and the breast cancer resistance protein (Bcrp), we hypothesize that Bcrp may also play a role in the proximal tubular secretion of mercuric species. In order to test this hypothesis, the uptake of Hg2+ was examined initially using inside-out membrane vesicles containing Bcrp. The results of these studies suggest that Bcrp may be capable of transporting certain conjugates of Hg2+. To further characterize the role of Bcrp in the handling of mercuric ions and in the induction of Hg2+-induced nephropathy, Sprague–Dawley and Bcrp knockout (bcrp−/−) rats were exposed intravenously to a non-nephrotoxic (0.5 μmol·kg−1), a moderately nephrotoxic (1.5 μmol·kg−1) or a significantly nephrotoxic (2.0 μmol·kg−1) dose of HgCl2. In general, the accumulation of Hg2+ was greater in organs of bcrp−/− rats than in Sprague–Dawley rats, suggesting that Bcrp may play a role in the export of Hg2+ from target cells. Within the kidney, cellular injury and necrosis was more severe in bcrp−/− rats than in controls. The pattern of necrosis, which was localized in the inner cortex and the outer stripe of the outer medulla, was significantly different from that observed in Mrp2-deficient animals. These findings suggest that Bcrp may be involved in the cellular export of select mercuric species and that its role in this export may differ from that of Mrp2. - Highlights: • Bcrp may mediate transport of mercury out of proximal tubular cells. • Hg-induced nephropathy was more severe in Bcrp knockout rats. • Bcrp and Mrp2 may differ in their ability to transport Hg

  14. Toxicological significance of renal Bcrp: Another potential transporter in the elimination of mercuric ions from proximal tubular cells

    Bridges, Christy C., E-mail: bridges_cc@mercer.edu; Zalups, Rudolfs K.; Joshee, Lucy

    2015-06-01

    Secretion of inorganic mercury (Hg{sup 2+}) from proximal tubular cells into the tubular lumen has been shown to involve the multidrug resistance-associated protein 2 (Mrp2). Considering similarities in localization and substrate specificity between Mrp2 and the breast cancer resistance protein (Bcrp), we hypothesize that Bcrp may also play a role in the proximal tubular secretion of mercuric species. In order to test this hypothesis, the uptake of Hg{sup 2+} was examined initially using inside-out membrane vesicles containing Bcrp. The results of these studies suggest that Bcrp may be capable of transporting certain conjugates of Hg{sup 2+}. To further characterize the role of Bcrp in the handling of mercuric ions and in the induction of Hg{sup 2+}-induced nephropathy, Sprague–Dawley and Bcrp knockout (bcrp{sup −/−}) rats were exposed intravenously to a non-nephrotoxic (0.5 μmol·kg{sup −1}), a moderately nephrotoxic (1.5 μmol·kg{sup −1}) or a significantly nephrotoxic (2.0 μmol·kg{sup −1}) dose of HgCl{sub 2}. In general, the accumulation of Hg{sup 2+} was greater in organs of bcrp{sup −/−} rats than in Sprague–Dawley rats, suggesting that Bcrp may play a role in the export of Hg{sup 2+} from target cells. Within the kidney, cellular injury and necrosis was more severe in bcrp{sup −/−} rats than in controls. The pattern of necrosis, which was localized in the inner cortex and the outer stripe of the outer medulla, was significantly different from that observed in Mrp2-deficient animals. These findings suggest that Bcrp may be involved in the cellular export of select mercuric species and that its role in this export may differ from that of Mrp2. - Highlights: • Bcrp may mediate transport of mercury out of proximal tubular cells. • Hg-induced nephropathy was more severe in Bcrp knockout rats. • Bcrp and Mrp2 may differ in their ability to transport Hg.

  15. Models for coupling of salt and water transport; Proximal tubular reabsorption in Necturus kidney.

    Sackin, H; Boulpaep, E L

    1975-12-01

    Models for coupling of salt and water transport are developed with two important assumptions appropriate for leaky epithelia. (a) The tight junction is permeable to both sale and water. (b) Active Na transport into the lateral speces is assumed to occur uniformly along the length of the channel. The proposed models deal specifically with the intraepithelial mechanism of proximal tubular resbsorption in the Necturus kidney although they have implications for epithelial transport in the gallbladder and small intestine as well. The first model (continuous version) is similar to the standing gradient model devised by Diamond and Bossert but used different boundary conditions. In contrast to Diamond and Bossert's model, the predicted concentration profiles are relatively flat with no sizable gradients along the interspace. The second model (compartment version) expands Curran's model of epithelial salt and water transport by including additional compartments and considering both electrical and chemical driving forces for individual Na and Cl ions as well as hydraulic and osmotic driving forces for water. In both models, ion and water fluxes are investigated as a function of the transport parameters. The behavior of the models is consistent with previously suggested mechanisms for the control of net transport, particularly during saline diuresis. Under all conditions the predicted ratio of net solute to solvent flux, or emergent concentration, deviates from exact isotonicity (except when the basement membrane has an appreciable salt reflection coefficient). However, the degree of hypertonicity may be small enough to be experimentally indistinguishable from isotonic transport. PMID:1104761

  16. Modeling of an immobilized lipase tubular reactor for the production of glycerol and fatty acids from oils

    Advances in the design of a bioreactor in the fats and oils industry have permitted the hydrolysis of triglycerides in mild conditions and improved productivity while avoiding the formation of unwanted byproducts. The present work develops a mathematical model that describes the hydrolytic activity of a tubular reactor with immobilized lipases for the production of glycerol and fatty acids from the oil trade. Runge Kuttas numerical method of high order has been applied, considering that there is no accumulation of the substratum in the surface of the membrane, where the enzyme is. At the same time, different equations based on the kinetic model of Michaelis Mentens and the Ping-Pong bi-bi mechanism were examined. Experimental data in discontinuous systems are the basis for the development of the quantitative mathematical model that was used to simulate the process computationally. The obtained results allow for optimizing both the operative variables and the economic aspects of industrial processes. (Author)

  17. Numerical investigation of cavitation performance on bulb tubular turbine

    Sun, L. G.; Guo, P. C.; Zheng, X. B.; Luo, X. Q.

    2016-05-01

    The cavitation flow phenomena may occur in the bulb tubular turbine at some certain operation conditions, which even decrease the performance of units and causes insatiably noise and vibration when it goes worse. A steady cavitating flow numerical simulations study is carried out on the bulb tubular unit with the same blade pitch angle and different guide vane openings by using the commercial code ANSYS CFX in this paper. The phenomena of cavitation induction areas and development process are obtained and draws cavitation performance curves. The numerical results show that the travelling bubble cavity is the main types of cavitation development over a wide operating range of discharge and this type of cavitation begins to sensitive to the value of cavitation number when the discharge exceeding a certain valve, in this condition, it can lead to a severe free bubble formation with the gradually decrement of cavitation number. The reported cavitation performance curves results indicate that the flow blockage incident would happen because of a mount of free bubble formation in the flow passage when the cavity developed to certain extend, which caused head drop behavior and power broken dramatically and influenced the output power.

  18. High temperature fatigue experiments on welded stainless steel tubular elements

    One of the most important problems concerning the design of advanced type reactors regards the high temperature low-cycle fatigue behaviour of structural elements. Design Guides and Codes report reference data, mainly based on strain range versus failure cycles results, which have been determined by various researchers. The data have been obtained through different test techniques applied to different types of specimens. As a consequence such data are not easily correlated; moreover at present an exhaustive series of results about high temperature low-cycle fatigue behaviour of structures is not available. A test rig has been designed to perform high temperature fatigue experiments on AISI 304 stainless steel tubular elements of 500 mm length, 60.3 mm outer diameter and 2 mm thickness, they are composed of two butt welded tubular elements with welded end flanges. During the experiments it is possible to control the axial strain range, the strain rate and the hold time; the specimen temperature is obtained by an inner heating device, controlled by a series of measuring thermocouples; until now the imposed temperature is 6500C. The first results show a marked reduction of the number of cycles at failure, if compared with existing data about small size specimens; the measurement of residual plastic strains shows clearly non-uniform distribution of the plastic zones. (Auth.)

  19. Surface and interfacial creases in a bilayer tubular soft tissue

    Razavi, Mir Jalil; Pidaparti, Ramana; Wang, Xianqiao

    2016-08-01

    Surface and interfacial creases induced by biological growth are common types of instability in soft biological tissues. This study focuses on the criteria for the onset of surface and interfacial creases as well as their morphological evolution in a growing bilayer soft tube within a confined environment. Critical growth ratios for triggering surface and interfacial creases are investigated both analytically and numerically. Analytical interpretations provide preliminary insights into critical stretches and growth ratios for the onset of instability and formation of both surface and interfacial creases. However, the analytical approach cannot predict the evolution pattern of the model after instability; therefore nonlinear finite element simulations are carried out to replicate the poststability morphological patterns of the structure. Analytical and computational simulation results demonstrate that the initial geometry, growth ratio, and shear modulus ratio of the layers are the most influential factors to control surface and interfacial crease formation in this soft tubular bilayer. The competition between the stretch ratios in the free and interfacial surfaces is one of the key driving factors to determine the location of the first crease initiation. These findings may provide some fundamental understanding in the growth modeling of tubular biological tissues such as esophagi and airways as well as offering useful clues into normal and pathological functions of these tissues.

  20. Renal Tubular Functions in Children with Primary Nocturnal Enuresis

    Süleyman Kalman

    2012-03-01

    Full Text Available Introduction: The etiology of primary nocturnal enuresis (PNE is multifactorial. The effects of genetic and hormonal factors, sleep disorders, and bladder dysfunction have been claimed. The other factors include increased urine production at night and impairment of the circadian rhythm of antidiuretic hormone. Aim: To investigate renal tubular functions in children with PNE. Methods: Forty patients with PNE were included in the study. Urine density, FENa, FEK and TRP were analyzed in daytime and nighttime urine. Results: The mean nighttime urine density was 1020.12±7.38 and the mean daytime urine density was 1013.20±7.11 (p0.05. Conclusion: Urine density in children with PNE was lower at night. However, there was no difference in of FENa, FEK and TRP. Further studies are needed in order to investigate renal tubular functions in children with PNE (The Me di cal Bul le tin of Ha se ki 2012; 50: 10-3

  1. Understanding shape and morphology of unusual tubular starch nanocrystals.

    Gong, Bei; Liu, Wenxia; Tan, Hua; Yu, Dehai; Song, Zhaoping; Lucia, Lucian A

    2016-10-20

    Starch nanocrystals (SNC) are aptly described as the insoluble degradation byproducts of starch granules that purportedly display morphologies that are platelet-like, round, square, and oval-like. In this work, we reported the preparation of SNC with unprecedented tubular structures through sulfuric acid hydrolysis of normal maize starch, subsequent exposure to ammonia and relaxation at 4°C. High-resolution transmission electron microscopy observation clearly proved that the SNCs possess tubular nanostructures with polygonal cross-section. After further reviewing the transformations of SNC by acid hydrolysis, ammonia treatment, and curing time at 4°C, a mechanism for T-SNC formation is suggested. It is conjectured that T-SNC gradually self-assembles by combination of smaller platelet-like/square nanocrystals likely loosely aggregated by starch molecular chains from residual amorphous regions. This work paves the way for the pursuit of new approaches for the preparation of starch-based nanomaterials possessing unique morphologies. PMID:27474612

  2. Nano-tubular cellulose for bioprocess technology development.

    Athanasios A Koutinas

    Full Text Available Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC justifies its suitability for use in "cold pasteurization" processes and its promoting activity in bioprocessing (fermentation. The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator. Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc.

  3. Advances in tubular solid oxide fuel cell technology

    Singhal, S.C. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

    1996-12-31

    The design, materials and fabrication processes for the earlier technology Westinghouse tubular geometry cell have been described in detail previously. In that design, the active cell components were deposited in the form of thin layers on a ceramic porous support tube (PST). The tubular design of these cells and the materials used therein have been validated by successful electrical testing for over 65,000 h (>7 years). In these early technology PST cells, the support tube, although sufficiently porous, presented an inherent impedance to air flow toward air electrode. In order to reduce such impedance to air flow, the wall thickness of the PST was first decreased from the original 2 mm (the thick-wall PST) to 1.2 mm (the thin-wall PST). The calcia-stabilized zirconia support tube has now been completely eliminated and replaced by a doped lanthanum manganite tube in state-of-the-art SOFCs. This doped lanthanum manganite tube is extruded and sintered to about 30 to 35 percent porosity, and serves as the air electrode onto which the other cell components are fabricated in thin layer form. These latest technology cells are designated as air electrode supported (AES) cells.

  4. Hierarchy in inorganic membranes.

    Caro, Juergen

    2016-06-13

    Thin films of a few μm thickness for particle filtration and gas separation cannot be applied as self-supporting layers since they are mechanically insufficiently strong. Therefore, these top layers for particle filtration and gas separation are usually deposited on porous mechanically strong supports with a hierarchical pore structure. To reduce the pressure drop of a gas stream over the membrane and to ensure high fluxes in filtration and gas separation, the cross section of the support is usually asymmetric or graded with a small thickness of the layer with the smallest pore size called the top layer. Since the pressure drop over a capillary with radius r is ∼r(4), the layer with the smallest pore size should be as thin as possible. The disk-like planar supports are usually prepared by sequential tape casting which is an expensive technology. Tubular supports with a hierarchical cross section can be prepared in one step by hollow fiber spinning, double mantle spinning or centrifugal casting. PMID:26466665

  5. A Model of Direct Contact Membrane Distillation of Black Currant Juice

    Jensen, Morten Busch; Christensen, Knud Villy; Andrésen, René;

    2011-01-01

    -side spacing of tubular-type unit."  Turtuosity and porosity are characteristics of the membrane in use and have been estimated base don eksperimental studies on destillation of pure water. The fitted model shows a good fit to experimental data obtained by destillation of black currant juice....

  6. Membrane Processes.

    Pellegrin, Marie-Laure; Burbano, Marie S; Sadler, Mary E; Diamond, Jason; Baker, Simon; Greiner, Anthony D; Arabi, Sara; Wong, Joseph; Doody, Alexandra; Padhye, Lokesh P; Sears, Keith; Kistenmacher, Peter; Kent, Fraser; Tootchi, Leila; Aguinaldo, Jorge; Saddredini, Sara; Schilling, Bill; Min, Kyungnan; McCandless, Robert; Danker, Bryce; Gamage, Neranga P; Wang, Sunny; Aerts, Peter

    2016-10-01

    This review, for literature published in 2015, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:27620084

  7. Membrane Processes.

    Pellegrin, Marie-Laure; Sadler, Mary E; Greiner, Anthony D; Aguinaldo, Jorge; Min, Kyungnan; Zhang, Kai; Arabi, Sara; Burbano, Marie S; Kent, Fraser; Shoaf, Robert

    2015-10-01

    This review, for literature published in 2014, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, fixed film and anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:26420079

  8. Tubular Ectasia of the Rete testis: Echographic Findings in 43 Patients; Ectasia tubular de la rete testis: hallazgos ecograficos en 43 pacientes

    Aleixandre, A.; Ruiz, F.; Cugat, A. [Hospital Malva-rosa. Valencia (Spain); Fuster, A. V. [Universidad de Valencia. (Spain)

    2003-07-01

    Tubular ectasia of the retetestes is a benign lesion usually associated with epididymal abnormalities. It should be included in the differential diagnosis of intraparenchymatous cystic lesions. Its characteristic echographic image usually allows for a diagnosis without having to perform any other type of exploration. We present a review of 43 patients with tubular ectasia of the rete tests studied ultrasonically during a 7-year period. Intratesticular echographic findings are described, as well as associated extratesticular pathology. (Author) 24 refs.

  9. CLC-5 and KIF3B interact to facilitate CLC-5 plasma membrane expression, endocytosis, and microtubular transport: relevance to pathophysiology of Dent's disease.

    Reed, Anita A.C.; Loh, Nellie Y.; TERRYN, Sara; Lippiat, Jonathan D.; Partridge, Chris; Galvanovskis, Juris; Williams, Sian E; Jouret, François; Wu, Fiona T. F.; Courtoy, Pierre J.; Nesbit, M Andrew; Rorsman, Patrik; Devuyst, Olivier; Ashcroft, Frances M.; Thakker, Rajesh V

    2010-01-01

    Renal tubular reabsorption is important for extracellular fluid homeostasis and much of this occurs via the receptor-mediated endocytic pathway. This pathway is disrupted in Dent's disease, an X-linked renal tubular disorder that is characterized by low-molecular-weight proteinuria, hypercalciuria, nephrolithiasis, and renal failure. Dent's disease is due to mutations of CLC-5, a chloride/proton antiporter, expressed in endosomes and apical membranes of renal tubules. Loss of CLC-5 function a...

  10. Optimization of production conditions and material characteristics of tubular stabilizer bars

    Muhr, R.

    1983-08-01

    Weight reduction of car tubular stabilizer bars is studied. Optimization of prematerial, forming and tempering procedures, and surface treatment are discussed. Steel qualities and production conditions were examined for feasibility with sample stabilizer bars. It is concluded that tubular stabilizer bars can be manufactured and practically used in cars. Tube diameters must not be too small, otherwise the weight saving is minimal.

  11. Resetting of tubuloglomerular feedback: evidence for a humoral factor in tubular fluid.

    Häberle, D A; Davis, J M

    1984-04-01

    Experiments were performed on chronically salt-loaded rats to determine whether resetting of tubuloglomerular feedback is caused by changes in the sensitivity of the juxtaglomerular apparatus itself or by changes of tubular fluid composition. The feedback response was quantified in both salt-loaded and salt-deplete rats by measuring early proximal flow rate (EPF) during loop perfusion at 40, 10, and 0 nl/min using tubular fluid harvested from both groups and with Ringer solution. In salt-loaded rats endogenous tubular fluid produced only a small feedback response (EPF40-0 = 1.9 +/- 1.5 nl/min), whereas exogenous tubular fluid from salt-deplete rats or Ringer solution produced normal feedback responses (EPF40-0 = 15.4 +/- 2.0 and 10.6 +/- 1.7 nl/min, respectively). In salt-deplete rats, endogenous tubular fluid and Ringer solution produced feedback responses of similar magnitude (EPF40-0 = 14.2 +/- 1.8 and 13.0 +/- 2.0 nl/min, respectively) but exogenous tubular fluid from salt-loaded rats elicited only a small feedback response (EPF40-0 = 1.5 +/- 1.6 nl/min), indistinguishable from that seen in salt-loaded rats with endogenous tubular fluid. It is concluded that an inhibitory factor in the tubular fluid of chronically salt-loaded rats causes a reduction in tubuloglomerular feedback response. PMID:6720904

  12. Spectrum of mutations in the renin-angiotensin system genes in autosomal recessive renal tubular dysgenesis

    Gribouval, Olivier; Morinière, Vincent; Pawtowski, Audrey;

    2012-01-01

    Autosomal recessive renal tubular dysgenesis (RTD) is a severe disorder of renal tubular development characterized by early onset and persistent fetal anuria leading to oligohydramnios and the Potter sequence, associated with skull ossification defects. Early death occurs in most cases from anuri...

  13. Efficiency and temperature dependence of water removal by membrane dryers

    Leckrone, K. J.; Hayes, J. M.

    1997-01-01

    The vapor pressure of water in equilibrium with sorption sites within a Nafion membrane is given by log P(WN) = -3580/T + 10.01, where P(WN) is expressed in Torr and T is the membrane temperature, in kelvin. The efficiency of dryers based on selective permeation of water through Nafion can thus be enhanced by cooling the membrane. Residual water in effluents exceeds equilibrium levels if insufficient time is allowed for water to diffuse to the membrane surface as gas passes through the dryer. For tubular configurations, this limitation can be avoided if L > or = Fc(10(3.8)/120 pi D), where L is the length of the tubular membrane, in centimeters, Fc is the gas flow rate, in mL/ min, and D is the diffusion coefficient for water in the carrier gas at the operating temperature of the dryer, in cm2/s. An efficient dryer that at room temperature dries gas to a dew point of -61 degrees C is described; the same dryer maintained at 0 degrees C yields a dew point of -80 degrees C and removes water as effectively as Mg(ClO4)2 or a dry ice/acetone slush. The use of Nafion membranes to construct devices capable of delivering gas streams with low but precisely controlled humidities is discussed.

  14. Excitability of the T-tubular system in rat skeletal muscle: roles of K+ and Na+ gradients and Na+-K+ pump activity.

    Nielsen, O B; Ørtenblad, N; Lamb, G D; Stephenson, D G

    2004-05-15

    Strenuous exercise causes an increase in extracellular [K(+)] and intracellular Na(+) ([Na(+)](i)) of working muscles, which may reduce sarcolemma excitability. The excitability of the sarcolemma is, however, to some extent protected by a concomitant increase in the activity of muscle Na(+)-K(+) pumps. The exercise-induced build-up of extracellular K(+) is most likely larger in the T-tubules than in the interstitium but the significance of the cation shifts and Na(+)-K(+) pump for the excitability of the T-tubular membrane and the voltage sensors is largely unknown. Using mechanically skinned fibres, we here study the role of the Na(+)-K(+) pump in maintaining T-tubular function in fibres with reduced chemical K(+) gradient. The Na(+)-K(+) pump activity was manipulated by changing [Na(+)](i). The responsiveness of the T-tubules was evaluated from the excitation-induced force production of the fibres. Compared to control twitch force in fibres with a close to normal intracellular [K(+)] ([K(+)](i)), a reduction in [K(+)](i) to below 60 mM significantly reduced twitch force. Between 10 and 50 mM Na(+), the reduction in force depended on [Na(+)](i), the twitch force at 40 mM K(+) being 22 +/- 4 and 54 +/- 9% (of control force) at a [Na(+)](i) of 10 and 20 mM, respectively (n= 4). Double pulse stimulation of fibres at low [K(+)](i) showed that although elevated [Na(+)](i) increased the responsiveness to single action potentials, it reduced the capacity of the T-tubules to respond to high frequency stimulation. It is concluded that a reduction in the chemical gradient for K(+), as takes place during intensive exercise, may depress T-tubular function, but that a concomitant exercise-induced increase in [Na(+)](i) protects T-tubular function by stimulating the Na(+)-K(+) pump. PMID:15034125

  15. Deducing the symmetry of helical assemblies: Applications to membrane proteins.

    Coudray, Nicolas; Lasala, Ralph; Zhang, Zhening; Clark, Kathy M; Dumont, Mark E; Stokes, David L

    2016-08-01

    Helical reconstruction represents a convenient and powerful approach for structure determination of macromolecules that assemble into helical arrays. In the case of membrane proteins, formation of tubular crystals with helical symmetry represents an attractive alternative, especially when their small size precludes the use of single-particle analysis. An essential first step for helical reconstruction is to characterize the helical symmetry. This process is often daunting, due to the complexity of helical diffraction and to the low signal-to-noise ratio in images of individual assemblies. Furthermore, the large diameters of the tubular crystals produced by membrane proteins exacerbates the innate ambiguities that, if not resolved, will produce incorrect structures. In this report, we describe a set of tools that can be used to eliminate ambiguities and to validate the choice of symmetry. The first approach increases the signal-to-noise ratio along layer lines by incoherently summing data from multiple helical assemblies, thus producing several candidate indexing schemes. The second approach compares the layer lines from images with those from synthetic models built with the various candidate schemes. The third approach uses unit cell dimensions measured from collapsed tubes to distinguish between these candidate schemes. These approaches are illustrated with tubular crystals from a boron transporter from yeast, Bor1p, and a β-barrel channel from the outer membrane of E. coli, OmpF. PMID:27255388

  16. VALIDATION OF SIMULATION MODELS FOR DIFFERENTLY DESIGNED HEAT-PIPE EVACUATED TUBULAR COLLECTORS

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    2007-01-01

    Differently designed heat-pipe evacuated tubular collectors have been investigated theoretically and experimentally. The theoretical work has included development of two TRNSYS [1] simulation models for heat-pipe evacuated tubular collectors utilizing solar radiation from all directions. One model...... is developed for heat-pipe evacuated tubular collectors with flat fins and one model is developed for heat-pipe evacuated tubular collectors with curved fins. The models are characterized by detailed calculations of the heat transfer processes in the fins, by detailed shadow modeling and by fins with...... selective coating on both sides. The input to the models is thus not a simple collector efficiency expression but the actual collector geometry. In this study, the TRNSYS models are validated with measurements for four differently designed heat-pipe evacuated tubular collectors. The collectors are produced...

  17. Renal Function in Diabetic Disease Models: The Tubular System in the Pathophysiology of the Diabetic Kidney

    Vallon, Volker; Thomson, Scott C.

    2013-01-01

    Diabetes mellitus affects the kidney in stages. At the onset of diabetes mellitus, in a subset of diabetic patients the kidneys grow large, and glomerular filtration rate (GFR) becomes supranormal, which are risk factors for developing diabetic nephropathy later in life. This review outlines a pathophysiological concept that focuses on the tubular system to explain these changes. The concept includes the tubular hypothesis of glomerular filtration, which states that early tubular growth and sodium-glucose cotransport enhance proximal tubule reabsorption and make the GFR supranormal through the physiology of tubuloglomerular feedback. The diabetic milieu triggers early tubular cell proliferation, but the induction of TGF-β and cyclin-dependent kinase inhibitors causes a cell cycle arrest and a switch to tubular hypertrophy and a senescence-like phenotype. Although this growth phenotype explains unusual responses like the salt paradox of the early diabetic kidney, the activated molecular pathways may set the stage for tubulointerstitial injury and diabetic nephropathy. PMID:22335797

  18. VALIDATION OF SIMULATION MODELS FOR DIFFERENTLY DESIGNED HEAT-PIPE EVACUATED TUBULAR COLLECTORS

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    Differently designed heat-pipe evacuated tubular collectors have been investigated theoretically and experimentally. The theoretical work has included development of two TRNSYS [1] simulation models for heat-pipe evacuated tubular collectors utilizing solar radiation from all directions. One model...... is developed for heat-pipe evacuated tubular collectors with flat fins and one model is developed for heat-pipe evacuated tubular collectors with curved fins. The models are characterized by detailed calculations of the heat transfer processes in the fins, by detailed shadow modeling and by fins with...... selective coating on both sides. The input to the models is thus not a simple collector efficiency expression but the actual collector geometry. In this study, the TRNSYS models are validated with measurements for four differently designed heat-pipe evacuated tubular collectors. The collectors are produced...

  19. Dysfunctional tubular endoplasmic reticulum constitutes a pathological feature of Alzheimer's disease.

    Sharoar, M G; Shi, Q; Ge, Y; He, W; Hu, X; Perry, G; Zhu, X; Yan, R

    2016-09-01

    Pathological features in Alzheimer's brains include mitochondrial dysfunction and dystrophic neurites (DNs) in areas surrounding amyloid plaques. Using a mouse model that overexpresses reticulon 3 (RTN3) and spontaneously develops age-dependent hippocampal DNs, here we report that DNs contain both RTN3 and REEPs, topologically similar proteins that can shape tubular endoplasmic reticulum (ER). Importantly, ultrastructural examinations of such DNs revealed gradual accumulation of tubular ER in axonal termini, and such abnormal tubular ER inclusion is found in areas surrounding amyloid plaques in biopsy samples from Alzheimer's disease (AD) brains. Functionally, abnormally clustered tubular ER induces enhanced mitochondrial fission in the early stages of DN formation and eventual mitochondrial degeneration at later stages. Furthermore, such DNs are abrogated when RTN3 is ablated in aging and AD mouse models. Hence, abnormally clustered tubular ER can be pathogenic in brain regions: disrupting mitochondrial integrity, inducing DNs formation and impairing cognitive function in AD and aging brains. PMID:26619807

  20. Fabrication of nanotubules of thermoelectric gamma-Na0.7CoO2 using porous aluminum oxide membrane as supporting template

    Liu, Chia-Jyi; Chen, Shu-Yo; Shih, Long-Jiann

    2009-01-01

    We report the successful synthesis of nanotubules of thermoelectric materials gamma-NaxCoO2 using two different sol-gel routes aided by porous anodized aluminium oxide (AAO) membrane as supporting templates. The gamma-NaxCoO2 nanotubule using urea-based route can be achieved at 650 degree C at a heating rate of 1 degree C/min and held for 4h. The gamma-NaxCoO2 nanotubule using citric acid-based route can be achieved at 500 degree C using a rapid-heat-up procedure and held for 30 min. The prod...

  1. Facile fabrication of Ag dendrite-integrated anodic aluminum oxide membrane as effective three-dimensional SERS substrate

    Zhang, Cong-yun; Lu, Ya; Zhao, Bin; Hao, Yao-wu; Liu, Ya-qing

    2016-07-01

    A novel surface enhanced Raman scattering (SERS)-active substrate has been successfully developed, where Ag-dendrites are assembled on the surface and embedded in the channels of anodic aluminum oxide (AAO) membrane, via electrodeposition in AgNO3/PVP aqueous system. Reaction conditions were systematically investigated to attain the best Raman enhancement. The growth mechanism of Ag dendritic nanostructures has been proposed. The Ag dendrite-integrated AAO membrane with unique hierarchical structures exhibits high SERS activity for detecting rhodamine 6G with a detection limit as low as 1 × 10-11 M. Furthermore, the three-dimensional (3D) substrates display a good reproducibility with the average intensity variations at the major Raman peak less than 12%. Most importantly, the 3D SERS substrates without any surface modification show an outstanding SERS response for the molecules with weak affinity for noble metal surfaces. The potential application for the detection of polycyclic aromatic hydrocarbons (PAHs) was evaluated with fluoranthene as Raman target molecule and a sensitive SERS detection with a limit down to 10-8 M was reached. The 3D SERS-active substrate shows promising potential for rapid detection of trace organic pollutants even weak affinity molecules in the environment.

  2. Rab22a Regulates the Recycling of Membrane Proteins Internalized Independently of ClathrinV⃞

    Weigert, Roberto; Yeung, Albert Chi; Li, Jean; Donaldson, Julie G.

    2004-01-01

    Plasma membrane proteins that are internalized independently of clathrin, such as major histocompatibility complex class I (MHCI), are internalized in vesicles that fuse with the early endosomes containing clathrin-derived cargo. From there, MHCI is either transported to the late endosome for degradation or is recycled back to the plasma membrane via tubular structures that lack clathrin-dependent recycling cargo, e.g., transferrin. Here, we show that the small GTPase Rab22a is associated wit...

  3. Ceramic membranes for high temperature hydrogen separation

    Fain, D.E.; Roettger, G.E. [Oak Ridge K-25 Site, TN (United States)

    1996-08-01

    Ceramic gas separation membranes can provide very high separation factors if the pore size is sufficiently small to separate gas molecules by molecular sieving and if oversized pores are adequately limited. Ceramic membranes typically have some pores that are substantially larger than the mean pore size and that should be regarded as defects. To assess the effects of such defects on the performance of ceramic membranes, a simple mathematical model has been developed to describe flow through a gas separation membrane that has a primary mode of flow through very small pores but that has a secondary mode of flow through undesirably large pores. This model permits separation factors to be calculated for a specified gas pair as a function of the molecular weights and molecular diameters of the gases, the membrane pore diameter, and the diameter and number of defects. This model will be described, and key results from the model will be presented. The separation factors of the authors membranes continue to be determined using a permeance test system that measures flows of pure gases through a membrane at temperatures up to 275{degrees}C. A primary goal of this project for FY 1996 is to develop a mixed gas separation system for measuring the separation efficiency of membranes at higher temperatures. Performance criteria have been established for the planned mixed gas separation system and design of the system has been completed. The test system is designed to measure the separation efficiency of membranes at temperatures up to 600{degrees}C and pressures up to 100 psi by separating the constituents of a gas mixture containing hydrogen. The system will accommodate the authors typical experimental membrane that is tubular and has a diameter of about 9 mm and a length of about 23 cm. The design of the new test system and its expected performance will be discussed.

  4. Characterization of hydrodynamics and mass transfer in two types of tubular electrochemical reactors

    Highlights: •The flow field of novel vertical-flow tubular electrochemical reactor with mesh electrodes (VTER) and traditional concentric tubular electrochemical reactor with plate electrodes (CTER) were compared. •The relationship between mass transfer coefficients and tube flow velocity and pressure drop in VTER and CTER were obtained. -- Abstract: Electrochemical treatment is an environmentally friendly method of removing pollutants from industrial wastewater. The tubular electrochemical reactor is one kind of electrochemical reactor. The current density distribution on the electrode surface in a traditional concentric tubular reactor is not homogeneous and the working area of the anodes and cathodes is unequal. Therefore, a novel tubular electrochemical reactor based on plug flow fluid orthogonal with mesh plate electrodes is presented. In this work, fluid flow and hydrodynamics of the vertical-flow tubular electrochemical reactor, such as velocity distribution and turbulent intensity distribution using computational fluid dynamics (CFD) method, are studied by comparing them to the traditional one. The electro-oxidation of phenol simulation wastewater treatment was developed to analyze the mass transfer performance of the two types of electrochemical reactors. In the novel tubular electrochemical reactor, due to the presence of mesh electrodes, the velocity distribution tended to be more homogeneous. In fact, the turbulent intensity clearly increased by 200% around the electrode surface. The kinetics of organic compounds removal in the novel tubular electrochemical reactor was also improved. Under the same flow rate, the improvement of the mass transfer coefficient for the novel tubular electrochemical reactor was more than twice that of the traditional tubular electrochemical reactor

  5. A regularized Newton method for locating thin tubular conductivity inhomogeneities

    We consider the inverse problem of determining the position and shape of a thin tubular object, such as for instance a wire, a thin channel or a curve-like crack, embedded in some three-dimensional homogeneous body from a single measurement of electrostatic currents and potentials on the boundary of the body. Using an asymptotic model describing perturbations of electrostatic potentials caused by such thin objects, we reformulate the inverse problem as a nonlinear operator equation. We establish Fréchet differentiability of the corresponding operator, compute its Fréchet derivative and set up a regularized Newton scheme to solve the inverse problem numerically. We discuss our implementation of this method and present numerical results for simulated forward data. (paper)

  6. Tubular colonic duplication - review of 1876-1981 literature

    Four cases of tubular colonic duplication are reported and 53 more are reviewed from 1876-1981 literature. Eighty percent of these patients had other anomalies, most notably genital and bladder duplications. Females outnumbered the males 37 to 20. Fifty percent of patients of either sex had some form of fistulous communication. In no one was the anomaly incompatible with life. Based on the anatomy of distal ends of duplicated colon, the patients are divided in five groups, for each of which the incidence and nature of concomitant anomalies are tabulated. Because of their anatomic complexity, most patients with colonic duplication require clinical evaluation by multiple subspecialists. We have also suggested the sequence and extent to which they should be evaluated by radiologists. (orig.)

  7. Novel Method Used to Inspect Curved and Tubular Structural Materials

    Roth, Don J.; Baaklini, George Y.; Carney, Dorothy V.; Bodis, James R.; Rauser, Richard W.

    1999-01-01

    At the NASA Lewis Research Center, a technique for the ultrasonic characterization of plates has been extended to tubes and to curved structures in general. In this technique, one performs measurements that yield a thickness-independent value of the local through-the-thickness speed of sound in a specimen. From such measurements at numerous locations across the specimen, one can construct a map of velocity as a function of location. The gradients of velocity indicated by such a map indicate local through-the-thickness-averaged microstructural parameters that affect the speed of sound. Such parameters include the pore volume fraction, mass density, fiber volume fraction (in the case of a composite material), and chemical composition. Apparatus was designed to apply the technique to tubular and other curved specimens.

  8. The role of sealing strips in tubular heat exchangers

    Tubular-type heat exchangers contain both baffle plates and sealing strips. The baffles force the flow to pass normal to the axes of the tubes and they serve to support the tubes. In order to facilitate assembly of the heat exchanger, a space exists between the tube bundle and the retaining shell. This space offers a hydraulic short circuit to the fluid, thus reducing the effectiveness of the device to exchange heat. Sealing strips, which are metal strips mounted on the shell and running parallel to the tubes, are introduced to partially block this leakage flow, thereby increasing the effectiveness of the device. The objectives of the research reported here are to experimentally determine the effectiveness of sealing strips, and to investigate the effects of their shape and location. Such results not only supply design information, but they serve to establish the accuracy of computer codes which have been developed for such heat exchangers. (author)

  9. [Diagnostic difficulties in a case of constricted tubular visual field].

    Dogaru, Oana-Mihaela; Rusu, Monica; Hâncu, Dacia; Horvath, Kárin

    2013-01-01

    In the paper below we present the clinical case of a 48 year old female with various symptoms associated with functional visual disturbance -constricted tubular visual fields, wich lasts from 6 years; the extensive clinical and paraclinical ophthalmological investigations ruled out the presence of an organic disorder. In the present, we suspect a diagnosis of hysteria, still uncertain, wich represented over time a big challenge in psychology and ophthalmology. The mechanisms and reasons for hysteria are still not clear and it could represent a fascinating research theme. The tunnel, spiral or star-shaped visual fields are specific findings in hysteria for patients who present visual disturbance. The question of whether or not a patient with hysterical visual impairment can or cannot "see" is still unresolved. PMID:24701812

  10. Seismic behavior of concrete filled steel tubular arch structures

    Xiong Feng; Sashi K Kunnath; Liu Haowu

    2005-01-01

    Shaking table tests of a 1:10 scale arch model performed to investigate the seismic behavior and resistance of concrete filled steel tubular (CFT) arch structures are described in this paper. The El-Centro record and Shanghai artificial wave were adopted as the input excitation. The entire test process can be divided into three stages depending on the lateral brace configurations, i.e., fully (five) braced, two braces removed, and all braces removed. A total of 46 tests, starting from the elastic state to failure condition, have been conducted. The natural vibration frequencies, responses of acceleration,displacement and strain were measured. From the test results, it is demonstrated that the CFT arch structures are capable of resisting severe ground motions and that CFT arches offer a credible alternative to reinforced concrete arches, especially in regions of high seismic intensity.

  11. Design of a Compact and Versatile Bench Scale Tubular Reactor

    R. Prasad

    2009-06-01

    Full Text Available A compact and versatile laboratory tubular reactor has been designed and fabricated keeping in view of reducing capital cost and minimising energy consumption for gas/vapor-phase heterogeneous catalytic reactions. The reactor is consisted of two coaxial corning glass tubes with a helical coil of glass tube in between the coaxial tubes serving as vaporiser and pre-heater, the catalyst bed is in the inner tube. A schematic diagram of the reactor with detailed dimensions and working principles are described. The attractive feature of the reactor is that the vaporiser, pre-heater and fixed bed reactor are merged in a single compact unit. Thus, the unit minimises separate vaporiser and pre-heater, also avoids separate furnaces used for them and eliminate auxiliary instrumentation such as temperature controller etc. To demonstrate the system operation and illustrate the key features, catalyst screening data and the efficient collection of complete, and accurate intrinsic kinetic data are provided for oxidation of CO over copper chromite catalyst. CO oxidation is an important reaction for auto-exhaust pollution control. The suitability of the versatile nature of the reactor has been ascertained for catalytic reactions where either volatile or vaporizable feeds can be introduced to the reaction zone, e.g. oxidation of iso-octane, reduction of nitric oxide, dehydrogenation of methanol, ethanol and iso-propanol, hydrogenation of nitrobenzene to aniline, etc. Copyright (c 2009 by BCREC. All Rights reserved.[Received: 10 February 2009, Accepted: 9 May 2009][How to Cite: R. Prasad, G. Rattan. (2009. Design of a Compact and Versatile Bench Scale Tubular Reactor. Bulletin of Chemical Reaction Engineering and Catalysis, 4(1: 5-9.  doi:10.9767/bcrec.4.1.1250.5-9][How to Link/ DOI: http://dx.doi.org/10.9767/bcrec.4.1.1250.5-9

  12. The tubular separate first wall for ITER-EDA

    The first wall (FW) is one of the most loaded plasma-facing components; the heat flux is such that the thermal stresses are the most important design concern. In addition, the FW must resist the eddy current induced during plasma disruption and the high pressure of the coolant and should maintain its properties under a fast neutron flux (dose up to 3 MW m-2).The tubular solution is the most suitable to cope with the thermal stresses; the use of a double wall reduces the risk of leaks inside the vacuum vessel by avoiding the growth of cracks through both walls: the soft brazing in between the walls stops the growth of cracks from one tube to the other. The eddy currents induced in the tubes are low and the halo current flowing poloidally in the tubes exerts a radial pressure which is supported by the blanket box via supporting points provided in between the FW and the blanket.The tubes are protected with a coating of beryllium or boron carbide against the radiation heat load during disruption, and with a coating of copper against runaway electrons. Fins attached to the tubes are provided to cope with the change in the toroidal width of the FW along the poloidal direction. The fins are also protected by coatings.The tubes can be made of steel to resist a heat flux of up to 1 MW m-2. For higher heat loads, copper or vanadium can be used. The tubular FW can be replaced independently of the blanket.The thermohydraulic, electromagnetic and dynamic analyses confirm the viability of the solution proposed. (orig.)

  13. The tubular separate first wall for ITER-EDA

    Pizzuto, A. [Associazione EURATOM-ENEA sulla Fusione, Centro Ricerche Frascati, Rome (Italy); Riccardi, B. [Associazione EURATOM-ENEA sulla Fusione, Centro Ricerche Frascati, Rome (Italy); Salpietro, E. [NET Team, Max-Planck-Institut fur Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Malavasi, G. [NET Team, Max-Planck-Institut fur Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    1995-03-01

    The first wall (FW) is one of the most loaded plasma-facing components; the heat flux is such that the thermal stresses are the most important design concern. In addition, the FW must resist the eddy current induced during plasma disruption and the high pressure of the coolant and should maintain its properties under a fast neutron flux (dose up to 3 MW m{sup -2}).The tubular solution is the most suitable to cope with the thermal stresses; the use of a double wall reduces the risk of leaks inside the vacuum vessel by avoiding the growth of cracks through both walls: the soft brazing in between the walls stops the growth of cracks from one tube to the other. The eddy currents induced in the tubes are low and the halo current flowing poloidally in the tubes exerts a radial pressure which is supported by the blanket box via supporting points provided in between the FW and the blanket.The tubes are protected with a coating of beryllium or boron carbide against the radiation heat load during disruption, and with a coating of copper against runaway electrons. Fins attached to the tubes are provided to cope with the change in the toroidal width of the FW along the poloidal direction. The fins are also protected by coatings.The tubes can be made of steel to resist a heat flux of up to 1 MW m{sup -2}. For higher heat loads, copper or vanadium can be used. The tubular FW can be replaced independently of the blanket.The thermohydraulic, electromagnetic and dynamic analyses confirm the viability of the solution proposed. (orig.).

  14. On milling of thin-wall conical and tubular workpieces

    Tsai, Mu-Ping; Tsai, Nan-Chyuan; Yeh, Cheng-Wei

    2016-05-01

    Thin-wall tubular-geometry workpieces have been widely applied in aircraft and medical industries. However, due to the special geometry of this kind of workpieces and induced poor machinability, the desired accuracy of machining tends to be greatly degraded, no matter what type of metal-cutting task such as milling, drilling or turning is undertaken. Though numerous research reports are available that the tool path can be planned on the basis of preset surface profile before actual milling operation is performed, it is still difficult to predict the real-time surface profile errors for peripheral milling of thin-wall tubular workpieces. Instead of relying on tool path planning, this research is focused on how to real-time formulate the appropriate applied cutting torque via feedback of spindle motor current. On the other hand, a few suitable cutting conditions which are able to prevent potential break/crack of thin-wall workpieces and enhance productivity but almost retain the same cutting quality is proposed in this research. To achieve this goal, estimated surface profile error on machined parts due to deflections caused by both tool and workpiece is studied at first. Traditionally, by adjusting cutting parameters such as feed rate or cut depth, the deflection of tool or workpiece can be expected not to exceed the specified limit. Instead, an effective feedback control loop is proposed by this work for applying real-time appropriate applied cutting torque to prevent potential break/crack of the thin-wall conical workpieces. The torque estimation approach by spindle motor current feedback and the corresponding fuzzy logic controller are employed. Compared with constant cutting torque during milling operation in tradition manner, it is observed that the time consumption of milling cycle by aid of the aforesaid fuzzy logic controller is greatly shortened while the resulted cutting accuracy upon finish of workpiece can be almost retained.

  15. Performance of anaerobic membrane bioreactor during digestion and thickening of aerobic membrane bioreactor excess sludge.

    Hafuka, Akira; Mimura, Kazuhisa; Ding, Qing; Yamamura, Hiroshi; Satoh, Hisashi; Watanabe, Yoshimasa

    2016-10-01

    In this study, we evaluated the performance of an anaerobic membrane bioreactor in terms of digestion and thickening of excess sludge from an aerobic membrane bioreactor. A digestion reactor equipped with an external polytetrafluoroethylene tubular microfiltration membrane module was operated in semi-batch mode. Solids were concentrated by repeated membrane filtration and sludge feeding, and their concentration reached 25,400mg/L after 92d. A high chemical oxygen demand (COD) removal efficiency, i.e., 98%, was achieved during operation. A hydraulic retention time of 34d and a pulse organic loading rate of 2200mg-COD/(L-reactor) gave a biogas production rate and biogas yield of 1.33L/(reactor d) and 0.08L/g-CODinput, respectively. The external membrane unit worked well without membrane cleaning for 90d. The transmembrane pressure reached 25kPa and the filtration flux decreased by 80% because of membrane fouling after operation for 90d. PMID:27394993

  16. Theoretical performance of a tubular integral collector storage system; Analisis teorico del comportamiento de un colector acumulador integrado tubular

    Lema, Alba; Barral, Jorge; Galimberti, Pablo [Universidad Nacional de Rio Cuarto (Argentina). Facultad de Ingenieria]. E-mail: alema@ing.unrc.edu.ar; Fasulo, Amilcar [Universidad de San Luis (Argentina). Dept. de Fisica]. E-mail afasulo@unsl.edu.ar

    2000-07-01

    A simplified theoretical dynamic computational model is developed in this work to evaluate the thermal behavior of a tubular integral-collector-storage system. A generic unit is studied under the hypothesis of isothermal nodes for the tubes and the corresponding pieces of transparent cover. The physical-mathematical model takes into account the energy balances relating the water of the tubes, the cover, and the collector surroundings. The model is codified in FORTRAN to perform simulations using the climatic local data and a typical hot water demand. The model is validated by comparing simulation results with experimental data obtained from a prototype built in a educational farm of the central part of Argentina. (author)

  17. Nanoscale phase behavior on flat and curved membranes

    The diverse physical properties of membranes play a critical role in many membrane associated biological processes. Proteins responsible for membrane transport can be affected by the lateral membrane order and lateral segregation of proteins is often controlled by the preference of certain membrane anchors for membrane phases having a physically ordered state. The dynamic properties of coexisting membrane phases are often studied by investigating their thermal behavior. Optical trapping of gold nanoparticles is a useful tool to generate local phase transitions in membranes. The high local temperatures surrounding an irradiated gold nanoparticle can be used to melt a part of a giant unilamellar lipid vesicle (GUV) which is then imaged using phase sensitive fluorophores embedded within the bilayer. By local melting of GUVs we reveal how a protein-free, one component lipid bilayer can mediate passive transport of fluorescent molecules by localized and transient pore formation. Also, we show how tubular membrane curvatures can be generated by optical pulling from the melted region on the GUV. This will allow us to measure the effect of membrane curvature on the phase transition temperature. (paper)

  18. Ceramic membranes for high temperature hydrogen separation

    Adcock, K.D.; Fain, D.E.; James, D.L.; Powell, L.E.; Raj, T.; Roettger, G.E.; Sutton, T.G. [East Tennessee Technology Park, Oak Ridge, TN (United States)

    1997-12-01

    The separative performance of the authors` ceramic membranes has been determined in the past using a permeance test system that measured flows of pure gases through a membrane at temperatures up to 275 C. From these data, the separation factor was determined for a particular gas pair from the ratio of the pure gas specific flows. An important project goal this year has been to build a Mixed Gas Separation System (MGSS) for measuring the separation efficiencies of membranes at higher temperatures and using mixed gases. The MGSS test system has been built, and initial operation has been achieved. The MGSS is capable of measuring the separation efficiency of membranes at temperatures up to 600 C and pressures up to 100 psi using a binary gas mixture such as hydrogen/methane. The mixed gas is fed into a tubular membrane at pressures up to 100 psi, and the membrane separates the feed gas mixture into a permeate stream and a raffinate stream. The test membrane is sealed in a stainless steel holder that is mounted in a split tube furnace to permit membrane separations to be evaluated at temperatures up to 600 C. The compositions of the three gas streams are measured by a gas chromatograph equipped with thermal conductivity detectors. The test system also measures the temperatures and pressures of all three gas streams as well as the flow rate of the feed stream. These data taken over a range of flows and pressures permit the separation efficiency to be determined as a function of the operating conditions. A mathematical model of the separation has been developed that permits the data to be reduced and the separation factor for the membrane to be determined.

  19. Evaluation of nephrotoxicity in vitro using a suspension of highly purified porcine proximal tubular cells and characterization of the cells in primary culture.

    Kruidering, M; Maasdam, D H; Prins, F A; de Heer, E; Mulder, G J; Nagelkerke, J F

    1994-01-01

    Proximal tubular cells (PTC) were isolated from porcine kidney by collagenase treatment, subsequently purified on a discontinuous density gradient and finally cultured. Porcine PTC (PPTC) in primary culture expressed keratin, characteristics of epithelia and brush border specific glycoproteins (FX1A). In addition, vimentin was present. All cells were negative for the endothelial marker pal-E. Less than 0.1% expressed the Tamm-Horsfall protein, characteristic of the distal tubule, while less than 0.3% of all cells in culture expressed desmin, characteristic of connective tissue (i.e. fibroblasts) and mesangial cells. Ultrastructural analysis revealed microvilli, tight junctions and abundant mitochondrial and lysosomes, all characteristics of proximal tubular cells. Freshly isolated PPTC were validated as in vitro model to detect nephrotoxicity by studying the effect of mercuric chloride, cis-platin, p-aminophenol and the halogenated alkenes 1,2 dichlorovinyl-l-cysteine, S-(1,1-difluoro-2,2-dichloroethyl)-L-cysteine (DCDFE-cys) and the glutathione conjugate of DCDFE on viability and mitochondrial membrane potential. The cells responded, time- and dose-dependently, to the nephrotoxic compounds with a decrease in mitochondrial membrane potential and loss of viability. The sensitivity of the porcine cells in detecting toxic effects corresponded favorably with in vitro systems derived from other animals. PMID:7859034

  20. Intracellular calcium ions as regulators of renal tubular sodium transport.

    Windhager, E; Frindt, G; Yang, J M; Lee, C O

    1986-09-15

    This review addresses the putative role of intracellular calcium ions in the regulation of sodium transport by renal tubules. Cytoplasmic calcium-ion activities in proximal tubules of Necturus are less than 10(-7) M and can be increased by lowering the electrochemical potential gradient for sodium ions across the peritubular cell membrane, or by addition of quinidine or ionomycin to peritubular fluid. Whereas lowering of the peritubular Na concentration increases cytosolic [Ca++] and [H+], ionomycin, a calcium ionophore, raises intracellular [Ca++] without decreasing pHi. The intracellular calcium-ion level is maintained by transport processes in the plasma membrane and membranes of intracellular organelles, as well as by calcium-binding proteins. Calcium ions inhibit net transport of sodium by reducing the rate of sodium entry across the luminal cell membrane. In the collecting tubule this inhibition is caused, at least in part, by an indirect reduction in the activity of the amiloride-sensitive sodium channel. PMID:2430134

  1. Porous membrane utilization in plant nutrient delivery

    Dreschel, T. W.; Hinkle, C. R.; Prince, R. P.; Knott, W. M., III

    1987-01-01

    A spacecraft hydroponic plant growth unit of tubular configuration, employing a microporous membrane as a capilary interface between plant roots and a nutrient solution, is presented. All three of the experimental trials undertaken successfully grew wheat from seed to harvest. Attention is given to the mass/seed, number of seeds/head, ratio of seed dry mass to total plant dry mass, production of tillers, and mass of seed/plant. Dry matter production is found to be reduced with increasing suction pressure; this is true for both average seed and average total dry matter/plant. This may be due to a reduction in water and nutrient availability through the microporous membrane.

  2. Hydrothermal growth of NiSe 2 tubular microcrystals assisted by PVA

    Fan, Hai; Zhang, Maofeng; Zhang, Xianwen; Qian, Yitai

    2009-10-01

    NiSe 2 tubular microcrystals assembled of nanoparticles have been prepared via a hydrothermal method in an ethanolamine and water mixed solution assisted by polyvinyl alcohol (PVA). The prepared tubular crystals with hexagonal structure are composed of nanoparticles with average diameter of 30 nm. It was found that the phase of the products could be adjusted by the molar ratio of the reactants (Ni/Se), and the morphology of the products could be greatly influenced by the quantity of surfactant PVA. Based on the experimental results, the possible formation mechanism of NiSe 2 tubular microcrystals is also discussed.

  3. Proximal tubular bicarbonate reabsorption and PCO2 in chronic metabolic alkalosis in the rat.

    Maddox, D A; Gennari, F J

    1983-01-01

    Studies were undertaken to define the pattern of proximal tubular bicarbonate reabsorption and its relation to tubular and capillary PCO2 in rats with chronic metabolic alkalosis (CMA). CMA was induced by administering furosemide to rats ingesting a low electrolyte diet supplemented with NaHCO3 and KHCO3. Proximal tubular bicarbonate reabsorption and PCO2 were measured in CMA rats either 4-7 or 11-14 d after furosemide injection, in order to study a wide range of filtered bicarbonate loads. A...

  4. HIV-1 Promotes Renal Tubular Epithelial Cell Protein Synthesis: Role of mTOR Pathway

    Rehman, Shabina; Husain, Mohammad; Yadav, Anju; Kasinath, Balakuntalam S.; Malhotra, Ashwani; Singhal, Pravin C.

    2012-01-01

    Tubular cell HIV-infection has been reported to manifest in the form of cellular hypertrophy and apoptosis. In the present study, we evaluated the role of mammalian target of rapamycin (mTOR) pathway in the HIV induction of tubular cell protein synthesis. Mouse proximal tubular epithelial cells (MPTECs) were transduced with either gag/pol-deleted NL4-3 (HIV/MPTEC) or empty vector (Vector/MPTEC). HIV/MPTEC showed enhanced DNA synthesis when compared with Vector/MPTECs by BRDU labeling studies....

  5. Advanced Numerical Modeling of Cracked Tubular K Joints: BEM and FEM Comparison

    Borges, L.; Chiew, S. P.; Nussbaumer, A.; Lee, C K

    2012-01-01

    A critical aspect in the design of tubular bridges is the fatigue performance of the structural joints. The estimation of a fatigue crack life using the linear elastic fracture mechanics (LEFM) theory involves the calculation of stress intensity factors (SIF) at a number of discrete crack depths. The most direct way is to carry out modeling by either the finite-element method (FEM) or the boundary-element method (BEM). For tubular joints commonly found in tubular bridges and off-shore structu...

  6. MOMENT - ROTATION BEHAVIOUR OF UNIVERSAL BEAM TO TUBULAR COLUMN CONNECTIONS USING REVERSE CHANNEL

    Li, Xue

    2012-01-01

    Steel tubular structures are becoming more widely used in recent years because of their excellent structural performance as well as appearance. For structures with steel hollow section (SHS) columns and concrete filled tubular (CFT) columns, several types of joint may be used to connect to wide flange beams. The topic of this research is a relatively new type of joint, the ‘reverse channel’ connection, in which the legs of a channel are welded to the tube thus converting the closed tubular co...

  7. Kidney specific protein-positive cells derived from embryonic stem cells reproduce tubular structures in vitro and differentiate into renal tubular cells.

    Ryuji Morizane

    Full Text Available Embryonic stem cells and induced pluripotent stem cells have the ability to differentiate into various organs and tissues, and are regarded as new tools for the elucidation of disease mechanisms as well as sources for regenerative therapies. However, a method of inducing organ-specific cells from pluripotent stem cells is urgently needed. Although many scientists have been developing methods to induce various organ-specific cells from pluripotent stem cells, renal lineage cells have yet to be induced in vitro because of the complexity of kidney structures and the diversity of kidney-component cells. Here, we describe a method of inducing renal tubular cells from mouse embryonic stem cells via the cell purification of kidney specific protein (KSP-positive cells using an anti-KSP antibody. The global gene expression profiles of KSP-positive cells derived from ES cells exhibited characteristics similar to those of cells in the developing kidney, and KSP-positive cells had the capacity to form tubular structures resembling renal tubular cells when grown in a 3D culture in Matrigel. Moreover, our results indicated that KSP-positive cells acquired the characteristics of each segment of renal tubular cells through tubular formation when stimulated with Wnt4. This method is an important step toward kidney disease research using pluripotent stem cells, and the development of kidney regeneration therapies.

  8. A/A/O工艺脱氮除磷运行效果分析%Analysis on running effect for biological nitrogen and phosphorus removal of A/A/O technology

    李曈; 郝瑞霞; 刘峰; 刘京

    2011-01-01

    为提高城市污水处理厂科学运行管理水平和出水质量,通过对某污水处理厂污水处理工艺的沿程采样分析,对比分析了A/A/O工艺脱氮除磷效果与工艺运行控制参数之间的相关关系。结果表明,A/A/O工艺对总氮去除率为83.2%,出水中氮的形态主要为硝酸盐氮;出水中总磷浓度基本达到一级A标准,总磷去除率在86.3%以上;缺氧段具有明显的反硝化聚磷作用;脱氮除磷效果与污泥负荷有反向变化关系,泥龄对磷的去除效果影响明显,当污泥负荷控制在0.15kg BOD5/(kg MLVSS.d)左右,泥龄控制在10~12 d时,可以同时%In order to improve the scientific management level and effluent quality of a municipal wastewater treatment plant(WWTP),the relationship between nitrogen and phosphorus removal effect and operating parameters of the A/A/O technology was studied by sampling and analyzing along the process in WWTP of Beijing.The results showed that the total nitrogen removal rate was 83.2%,and the main form of nitrogen was nitrate nitrogen in effluent.The TP concentration in effluent could reach the 1 grade A level of national discharging standard in China basically,and the TP removal rate was over 86.3%.The denitrifying phosphorus removal played a remarkable role in the anoxic phase of A/A/O process.The relationship between nitrogen and phosphorus removal effect and sludge loading expressed inverse variation.Sludge retain time(SRT) had an obvious impact on phosphorus removal.When the sludge loading was about 0.15 kg BOD5/(kg MLVSS·d)and the SRT was about 10~12 d in A/A/O process,nitrogen and phosphorus removal rates were up to 81% and 88%,respectively.There was an inverse variation relationship between the phosphorus accumulation and the sludge emission capacities in the wastewater treatment system.When the sludge emission capacities maintained about 2~2.5 percent of influent,phosphorus removal can be controlled in the stable and

  9. A/A/O工艺运行过程中磷的迁移与积累规律%Analysis on removing and accumulating approach of phosphorus in A/A/O technology

    郝瑞霞; 李瞳; 刘峰; 刘京

    2011-01-01

    To improve the scientific management level and effluent quality of a municipal wastewater treatment plant (WWTP), the relationship between the phosphorus removal approach and operating parameters of the A/A/O technology was analyzed by sampling and analyzing samples from the treatment technology process of a WWTP in Beijing, and also the phosphorus material balance was assessed for the sewage treatment system. The results showed that the denitrifying phosphorus removal played remarkably a role for phosphorus removal in the anoxic zone of A/A/O process. The absorption of phosphorus in anoxic zone had exceeded the quantity in the oxie zone. The nitrate concentration in the returned nitrifying liquid had an influence on the denitrifying phosphorus removal. The relationship between phosphorus removal and sludge load, sludge retain time (SRT) showed negative correlation. When the sludge load was about 0. 15 kg/( kg ~ d)and the SRT was about 10 - 12 d in A/A/O process, the phosphorus removal rate was up to 88%. There was also a negative correlation relationship between the phosphorus accumulation and the sludge emission capacities in the wastewater treat- ment system. When the sludge emission capacities were controlled to 2. 0 - 2.5 percent inflow of the treatment plant, the phosphorus removal efficiency could be kept on stable and economic status.%为提高污水处理厂科学运行管理水平和出水质量,通过对北京某污水处理厂污水处理工艺的沿程采样分析,研究A/A/O工艺运行过程中磷的迁移途径、除磷效率与工艺运行控制参数之间的相关性,并进行污水处理系统内部磷平衡核算.结果表明,A/A/O工艺缺氧段存在明显的反硝化聚磷作用,其吸磷量超过好氧段的,回流硝化液中硝酸盐质量浓度对反硝化聚磷作用有影响;除磷效果与污泥负荷、泥龄呈反向变化趋势,当污泥负荷控制在0.15k∥(kg

  10. Biofiksasi CO2 Oleh Mikroalga Chlamydomonas sp dalam Photobioreaktor Tubular

    Hadiyanto Hadiyanto

    2014-05-01

    Full Text Available Mikroalga memiliki potensi dalam membiofiksasi CO2 dan dapat dimanfaatkan untuk mengurangi kadar CO2 dalam gas pencemar. Pertumbuhan mikroalga sangat dipengaruhi oleh konsentrasi gas CO2 di dalam gas pencemar. Tujuan penelitian ini adalah untuk mengeetahui kemampuan mikroalga Chlamydomonas sp yang dikultivasi dalam photobioreaktor tubular dalam penyerapan gas CO2 serta untuk mengetahui konsentrasi maksimum gas CO2 dalam umpan untuk memproduksi biomasa mikroalga yang optimal. Percobaan dilakukan dnegan memvariasi laju alir dari 0.03 -0.071 L/menit dan konsentrasi CO2 dalam umpan 10-30%. Hasil penelitian menunjukkan bahwa biomasa mikroalga dapat diproduksi dengan maksimal dengan konsentrasi gas CO2 20% dengan laju alir 0.07 L/min. Semakin tinggi laju alir maka produksi biomasa alga semakin besar. Kecepatan pertumbuhan alga maksimum terjadi pada 0.31 /hari. Pada konsentrasi gas CO2 30%, terjadi substrate inhibition yang disebabkan carbon dalam bentuk ion bicarbonate tidak dapat dikonsumsi lagi di dalam kultur alga. Kata kunci : Mikroalga, chlamydomonas sp, biofiksasi CO2, biogas Abstract Microalgae have a potential for CO2 biofixation and therefore can be used to reduce the CO2 concentration in the gas pollutants. Moreover, microalgae growth is strongly affected by the concentration of CO2 in the exhaust gas pollutants. The objective of this research was to investigate the ability of microalgae Chlamydomonas sp which was cultivated in a tubular photobioreactor for CO2 absorption as well as to determine the maximum concentration of CO2 in the feed gas to obtain optimum microalgae biomass. The experiments were performed by varying the gas flow rate of 0.03 -0.071 L / min and the concentration of CO2 in the feed of 10-30%. The results showed that the maximum biomass of microalgae can be produced with CO2 concentration of 20% vol with a flow rate of 0.07 L / min. The result also showed that increasing the gas flow rate, the greater of the production of

  11. Experimental research and numerical simulation on impeller exit flow field of bulb tubular pump

    Three dimensional Laser Doppler Velocimetry (3D-LDV) technique was used to measure the impeller exit flow field of bulb tubular pump, the average velocity distribution of the exit section was obtained, and the energy performance of bulb tubular pump was obtained by model test. The flow field of tubular pump also simulated by CFD based on Navier-Stokes equations and RNG k-ε model. The calculated performance curve was consistent with the model test results, and the calculated velocities of impeller exit compared with the LDV measurement results, it was shown that the distribution of circumferential velocity and axial velocity were close to each other, but the radial velocity deviation between the LDV results and the CFD ones was obviously, the reasons of deviation were analyzed. The experimental results can provide the references for the impeller and diffuser design of tubular pumps, it also can improve the accuracy of calculation and perfect simulation.

  12. Physiological role of transverse-axial tubular system in cardiac ventricular myocytes: a simulation study

    Pásek, Michal; Šimurda, J.; Orchard, C.; Christé, G.

    Lyon : IEEE, 2005, s. 393-395. [Computers in cardiology. Lyon (FR), 25.09.2005-28.09.2005] Institutional research plan: CEZ:AV0Z20760514 Keywords : cardiac cell * tubular system * quantitative modelling Subject RIV: BO - Biophysics

  13. EVALUATION OF EVACUATED TUBULAR SOLAR COLLECTORS FOR LARGE SDHW SYSTEMS AND COMBINED SPACE HEATING SYSTEMS

    Qin, Lin; Furbo, Simon

    1999-01-01

    In the present study, detailed investigations on evacuated tubular solar collectors for large solarheating systems have been carried out. Four types of evacuated tubular solar collectors were used in theinvestigation. Based on laboratory tests, simulation models for the collectors were determined....... Based on thesemodels, the thermal performance of large solar domestic hot water (DHW) systems and combined domestichot water and space heating systems with the four evacuated tubular collectors was determined. To make acomparison with traditional flat-plate collectors, similar simulations were also...... carried out for systems with atypical flat-plate collector. The results show that the thermal advantage of evacuated tubular collectors variesgreatly from system to system, and increases with the solar fraction. Furthermore, the higher the operationtemperature of the collector in the system is, the...

  14. A tubular dielectric elastomer actuator: Fabrication, characterization and active vibration isolation

    Sarban, R.; Jones, R. W.; Mace, B. R.; Rustighi, E.

    2011-01-01

    This contribution reviews the fabrication, characterization and active vibration isolation performance of a core-free rolled tubular dielectric elastomer (DE) actuator, which has been designed and developed by Danfoss PolyPower A/S. PolyPower DE material, PolyPower (TM), is produced in thin sheets......) highlight the dominant dynamic characteristics of the core-free tubular actuator. It has been observed that all actuators have similar dynamic characteristics in a frequency range up to 1 kHz. A tubular actuator is then used to provide active vibration isolation (AVI) of a 250 g mass subject to shaker...... generated 'ground vibration'. An adaptive feedforward control approach is used to achieve this. The tubular actuator is shown to provide excellent isolation against harmonic vibratory disturbances with attenuation of the resulting 5 and 10 Hz harmonics being 66 and 23 dB, respectively. AVI against a narrow...

  15. Diaphragmatic suture with tubular stomach to prevent early delayed gastric emptying after esophagectomy

    Chao Sun; Weiping Shi; Yusheng Shu; Hongcan Shi; Shichun Lu; Kang Wang

    2015-01-01

    Objective The objective of this study was to evaluate the clinical ef icacy of a diaphragmatic suture with tubular stomach to prevent delayed gastric emptying (DGE) after esophagectomy through the cervico-tho-racoabdominal approach. Methods A total of 980 patients with esophageal cancer undergoing esophagectomy through the cer-vico-thoracoabdominal approach were retrospectively included in this study and divided into two groups. Al patients underwent tubular stomach creation (group A; n = 530) or a diaphragmatic suture and tubular stomach creation (group B; n = 450). The incidence of early DGE was observed. Results The incidence of early DGE in group A was significantly higher than that in group B (P Conclusion This observation study suggests that the use of a diaphragmatic suture with tubular stomach through the cervico-thoracoabdominal approach can decrease the incidence of early DGE after esopha-gectomy.

  16. Bidirectional signalling between EphA2 and ephrinA1 increases tubular cell attachment, laminin secretion and modulates erythropoietin expression after renal hypoxic injury.

    Rodriguez, Stéphane; Rudloff, Stefan; Koenig, Katrin Franziska; Karthik, Swapna; Hoogewijs, David; Huynh-Do, Uyen

    2016-08-01

    Acute kidney injury (AKI) is common in hospitalized patients and has a poor prognosis, the severity of AKI being linked to progression to chronic kidney disease. This stresses the need to search for protective mechanisms during the acute phase. We investigated kidney repair after hypoxic injury using a rat model of renal artery branch ligation, which led to an oxygen gradient vertical to the corticomedullary axis. Three distinct zones were observed: tubular necrosis, infarction border zone and preserved normal tissue. EphA2 is a receptor tyrosine kinase with pivotal roles in cell architecture, migration and survival, upon juxtacrine contact with its membrane-bound ligand EphrinA1. Following hypoxia, EphA2 was up-regulated in cortical and medullary tubular cells, while EphrinA1 was up-regulated in interstitial cells adjacent to peritubular capillaries. Moreover, erythropoietin (EPO) messenger RNA (mRNA) was strongly expressed in the border zone of infarcted kidney within the first 6 h. To gain more insight into the biological impact of EphA2 and EphrinA1 up-regulation, we activated the signalling pathways in vitro using recombinant EphrinA1/Fc or EphA2/Fc proteins. Stimulation of EphA2 forward signalling in the proximal tubular cell line HK2 increased cell attachment and laminin secretion at the baso-lateral side. Conversely, activation of reverse signalling through EphrinA1 expressed by Hep3B cells promoted EPO production at both the transcriptional and protein level. Strikingly, in co-culture experiments, juxtacrine contact between EphA2 expressing MDCK and EphrinA1 expressing Hep3B was sufficient to induce a significant up-regulation of EPO mRNA production in the latter cells, even in the absence of hypoxic conditions. The synergistic effects of EphA2 and hypoxia led to a 15-20-fold increase of EPO expression. Collectively, our results suggest an important role of EphA2/EphrinA1 signalling in kidney repair after hypoxic injury through stimulation of (i) tubular

  17. The fouling in the tubular heat exchanger of Algiers refinery

    Harche, Rima; Mouheb, Abdelkader; Absi, Rafik

    2016-05-01

    Crude oil fouling in refinery preheat exchangers is a chronic operational problem that compromises energy recovery in these systems. Progress is hindered by the lack of quantitative knowledge of the dynamic effects of fouling on heat exchanger transfer and pressure drops. In subject of this work is an experimental determination of the thermal fouling resistance in the tubular heat exchanger of the crude oil preheats trains installed in an Algiers refinery. By measuring the inlet and outlet temperatures and mass flows of the two fluids, the overall heat transfer coefficient has been determined. Determining the overall heat transfer coefficient for the heat exchanger with clean and fouled surfaces, the fouling resistance was calculated. The results obtained from the two cells of exchangers studies, showed that the fouling resistance increased with time presented an exponential evolution in agreement with the model suggested by Kern and Seaton, with the existence of fluctuation caused by the instability of the flow rate and the impact between the particles. The bad cleaning of the heat exchangers involved the absence of the induction period and caused consequently, high values of the fouling resistance in a relatively short period of time.

  18. Multi-scale tubular structure detection in ultrasound imaging.

    Hennersperger, Christoph; Baust, Maximilian; Waelkens, Paulo; Karamalis, Athanasios; Ahmadi, Seyed-Ahmad; Navab, Nassir

    2015-01-01

    We propose a novel, physics-based method for detecting multi-scale tubular features in ultrasound images. The detector is based on a Hessian-matrix eigenvalue method, but unlike previous work, our detector is guided by an optimal model of vessel-like structures with respect to the ultrasound-image formation process. Our method provides a voxel-wise probability map, along with estimates of the radii and orientations of the detected tubes. These results can then be used for further processing, including segmentation and enhanced volume visualization. Most Hessian-based algorithms, including the well-known Frangi filter, were developed for CTA or MRA; they implicitly assume symmetry about the vessel centerline. This is not consistent with ultrasound data. We overcome this limitation by introducing a novel filter that allows multi-scale estimation both with respect to the vessel's centerline and with respect to the vessel's border. We use manually-segmented ultrasound imagery from 35 patients to show that our method is superior to standard Hessian-based methods. We evaluate the performance of the proposed methods based on the sensitivity and specificity like measures, and finally demonstrate further applicability of our method to vascular ultrasound images of the carotid artery, as well as ultrasound data for abdominal aortic aneurysms. PMID:25069110

  19. Design and Analysis of Tubular Permanent Magnet Linear Wave Generator

    Jikai Si

    2014-01-01

    Full Text Available Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the linear velocity of permanent magnet rotary generator and the operating speed of TPMLWG, to determine the structure parameters of the TPMLWG. The new secondary structure of the TPMLWG contains surface-mounted permanent magnets and the interior permanent magnets, which form a series-parallel hybrid magnetic circuit, and their reasonable structure parameters are designed to get the optimum pole-arc coefficient. The electromagnetic field and temperature field of TPMLWG are analyzed using finite element method. It can be included that the sinusoidal characteristics of air gap flux density of the new secondary structure TPMLWG are improved, the cogging force as well as mechanical vibration is reduced in the process of operation, and the stable temperature rise of generator meets the design requirements when adopting the new secondary structure of the TPMLWG.

  20. Tubularized incised plate urethroplasty results in patients with proximal hypospadias

    Yasin Aydoğmuş

    2015-12-01

    Full Text Available Objective: To evaluate the results of the patients with primary proximal hypospadias repaired by “tubularized incised plate” urethroplasty (TIPU. Methods: Thirty-three patients who were operated with TIPU technique in our clinic between 2003-2011 for primary hypospadias with proximal penile and penoscrotal meatus were retrospectively evaluated. Evaluation of the success in this study was, “voiding without fistula”. Results: Mean age was 6.82±3.07 (1-13. Fifteen patients (45.4% had penoscrotal and 18 patients (54.6% had proximal penil meatus. Postoperative success was evaluated with direct vision of voiding at the time of un-catheterization, 2 weeks and 6 months after un-catheterization. Success rates were 5/15 and 10/18 after the first repair in the level penoscrotal and proximal penil, respectively. Overall success rate was 45.5% after the first repair. Patients with urethral fistula after first repair were undergone second repair, success rates were increased to 9/15 and 16/18 in the levels of penoscrotal and proximal penil, respectively. Overall success rate after second repair was 75.8%. Conclusion: TIPU may be confidently applied for the patients with proximal hypopadias in experienced clinics, if there is not an uretral cordi or/and abnormality in the development of urethral plate.

  1. Distal renal tubular acidosis with multiorgan autoimmunity: a case report.

    van den Wildenberg, Maria J; Hoorn, Ewout J; Mohebbi, Nilufar; Wagner, Carsten A; Woittiez, Arend-Jan; de Vries, Peter A M; Laverman, Gozewijn D

    2015-04-01

    A 61-year-old woman with a history of pernicious anemia presented with progressive muscle weakness and dysarthria. Hypokalemic paralysis (serum potassium, 1.4 mEq/L) due to distal renal tubular acidosis (dRTA) was diagnosed. After excluding several possible causes, dRTA was considered autoimmune. However, the patient did not meet criteria for any of the autoimmune disorders classically associated with dRTA. She had very high antibody titers against parietal cells, intrinsic factor, and thyroid peroxidase (despite normal thyroid function). The patient consented to a kidney biopsy, and acid-base transporters, anion exchanger type 1 (AE1), and pendrin were undetectable by immunofluorescence. Indirect immunofluorescence detected diminished abundance of AE1- and pendrin-expressing intercalated cells in the kidney, as well as staining by the patient's serum of normal human intercalated cells and parietal cells expressing the adenosine triphosphatase hydrogen/potassium pump (H(+)/K(+)-ATPase) in normal human gastric mucosa. The dRTA likely is caused by circulating autoantibodies against intercalated cells, with possible cross-reactivity against structures containing gastric H(+)/K(+)-ATPase. This case demonstrates that in patients with dRTA without a classic autoimmune disorder, autoimmunity may still be the underlying cause. The mechanisms involved in autoantibody development and how dRTA can be caused by highly specific autoantibodies against intercalated cells have yet to be determined. PMID:25533600

  2. Microbial acetate oxidation in horizontal rotating tubular bioreactor

    A Slavica; B Šantek; S Novak; V Marić

    2004-06-01

    The aim of this work was to investigate the possibility of conducting a continuous aerobic bioprocess in a horizontal rotating tubular bioreactor (HRTB). Aerobic oxidation of acetate by the action of a mixed microbial culture was chosen as a model process. The microbial culture was not only grown in a suspension but also in the form of a biofilm on the interior surface of HRTB. Efficiency of the bioprocess was monitored by determination of the acetate concentration and chemical oxygen demand (COD). While acetate inlet concentration and feeding rate influenced efficiency of acetate oxidation, the bioreactor rotation speed did not influence the bioprocess dynamics significantly. Gradients of acetate concentration and pH along HRTB were more pronounced at lower feeding rates. Volumetric load of acetate was proved to be the most significant parameter. High volumetric loads (above 2 g acetate l–1 h–1) gave poor acetate oxidation efficiency (only 17 to 50%). When the volumetric load was in the range of 0.60–1.75 g acetate l–1 h–1, acetate oxidation efficiency was 50–75%. At lower volumetric loads (0.14–0.58 g acetate l–1 h–1), complete acetate consumption was achieved. On the basis of the obtained results, it can be concluded that HRTB is suitable for conducting aerobic continuous bioprocesses.

  3. STUDY THE CREEP OF TUBULAR SHAPED FIBER REINFORCED COMPOSITES

    Najat J. Saleh

    2013-05-01

    Full Text Available Inpresent work tubular –shaped fiber reinforced composites were manufactured byusing two types of resins ( Epoxy and unsaturated polyester and separatelyreinforced with glass, carbon and kevlar-49 fibers (filament and woven roving,hybrid reinforcement composites of these fibers were also prepared. The fiberswere wet wound on a mandrel using a purposely designed winding machine,developed by modifying an ordinary lathe, in winding angle of 55° for filament. A creep test was made of either the fulltube or specimens taken from it. Creep was found to increase upon reinforcementin accordance to the rule of mixture and mainly decided by the type of singleor hybridized fibers. The creep behavior, showed that the observed strain tendsto appear much faster at higher temperature as compared with that exhibited atroom temperate. The creep rate also found to be depending on fiber type, matrixtype, and the fiber /matrix bonding. The creep energy calculated fromexperimental observations was found to exhibit highest value for hybridizedreinforcement.

  4. Metachronous tubulovillous and tubular adenomas of the anal canal.

    Nozawa, Hiroaki; Ishihara, Soichiro; Morikawa, Teppei; Tanaka, Junichiro; Yasuda, Koji; Ohtani, Kensuke; Nishikawa, Takeshi; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Kawai, Kazushige; Hata, Keisuke; Kazama, Shinsuke; Yamaguchi, Hironori; Sunami, Eiji; Kitayama, Joji; Fukayama, Masashi; Watanabe, Toshiaki

    2015-01-01

    Anal canal adenoma is an extremely rare disease that has the potential to transform into a malignant tumor. We herein presented a rare case of metachronous multiple adenomas of the anal canal. A 48-year-old woman underwent total colonoscopy following a positive fecal blood test. A 9-mm villous polyp arising from the posterior wall of the anal canal was removed by snare polypectomy. Histologically, the tumor was tubulovillous adenoma with high-grade dysplasia and the cut end was negative for tumor cells. Six years later, an elevated lesion, macroscopically five millimeters in size, was detected in the left wall of the anal canal in a follow-up colonoscopy. Local excision of the tumor was performed, and the lesion was pathologically confirmed to be tubular adenoma with high-grade dysplasia limited to the mucosa. The patient is currently alive without any evidence of recurrence for six months after surgery. Although she had a past history of cervical cancer, the multiple tumors arising in the anal canal were unlikely to be related to human papilloma virus infection. Our case report underscores the importance of careful observations throughout colonoscopy to detect precancerous lesions, particularly in anatomically narrow segments. PMID:26249723

  5. A single vibration mode tubular piezoelectric ultrasonic motor.

    He, Siyuan; Chiarot, Paul R; Park, Soonho

    2011-05-01

    A novel tubular ultrasonic motor is presented that uses only a single vibration bending mode of a piezoelectric tube to generate rotation. When the piezoelectric tube bends, the diagonal motion of points on selected areas at the ends of the tube generates forces with tangential components along the same circumferential direction, driving the rotors to rotate. Bi-directional motion is achieved by simply switching the direction of bending. Because only one vibration mode is used, the motor requires only one driving signal and no vibration mode coupling is needed, simplifying the design, fabrication, assembly, and operation of the device. Two prototypes [one with cut-in lead zirconate titanate (PZT) teeth and one with added metal teeth] were built and tested using PZT tubes available to the authors. The tubes have an outside diameter of 6.6 mm, inner diameter of 5.0 mm, and length of 25.4 mm. The working frequencies of the two motors are 27.6 and 23.5 kHz. The motors achieved a maximum no-load speed of 400 rpm and a stall torque of 300 μN·m. PMID:21622060

  6. The thermal decomposition of methane in a tubular reactor

    Kobayashi, Atsushi; Steinberg, M.

    1992-01-01

    The reaction rate of methane decomposition using a tubular reactor having a 1 inch inside diameter with an 8 foot long heated zone was investigated in the temperature range of 700 to 900 C with pressures ranging from 28.2 to 56.1 atm. Representing the rate by a conventional model, {minus}dC{sub CH4}/dt= k1 C{sub CH4} {minus}k2 C{sub H2}{sup 2}, the rate constant k1 for methane decomposition was determined. The activation energy, 31.3 kcal/mol, calculated by an Arrhenius Plot was lower than for previously published results for methane decomposition. This result indicates that submicron particles found in the reactor adhere to the inside of the reactor and these submicron high surface area carbon particles tend to catalyze the methane decomposition. The rate constant has been found to be approximately constant at 900 C with pressure range cited above. The rate of methane decomposition increases with methane partial pressure in first-order. The rate of the methane decomposition is favored by higher temperatures and pressures while the thermochemical equilibrium of methane decomposition is favored by lower pressures. 8 refs., 7 figs., 2 tabs.

  7. Quantitation of renal function with glomerular and tubular agents

    Quantitative methods to measure the glomerular and tubular function of the kidneys with radionuclides have been available for many years. They have not been widely used because the techniques and the calculations exceeded the scope of routine nuclear medicine practice. Validation of simplified methods and the introduction of computer technology have made measurement of the effective renal plasma flow (ERPF) and the glomerular filtration rate (GFR) simple enough so that they can be performed reproducibly in most nuclear medicine departments. The estimation of ERPF with radioiodinated OIH and GFR with /sup 99m/TcDTPA can be achieved in many ways, all of which yield clinically useful results. How to get the best results using the simplest methods is still unclear. The required accuracy depends on the intended clinical use. Our preference at the present time is to use a single or double plasma sample to calculate global ERPF or GFR, and to use the 1-2 min OIH or 1-3 min Tc-DTPA uptake to calculate relative function of the two kidneys (split function ERPF or GFR). The choice of method will be influenced by local factors, such as the nature of the patient population, the case volume, and the resources available. A desirable goal for future studies is to document carefully the capabilities and limitations of each alternative method, so that the choice can be rational

  8. The tubular separate first wall for ITER EDA

    The first wall is one of the most loaded plasma-facing components, the heat flux is such that the thermal stresses are the most important design concern. In addition, the First Wall shall resist the eddy current induced plasma disruption, the high pressure of the coolant without leaking (-6 Torr-lit/sec.) and it should maintain its properties under fast neutron flux (dose up to 3 MW/m2). The tubular solution is the most suitable one to cope with the thermal stresses, the use of double wall reduces the risk of leaks inside the vacuum vessel by avoiding the growth of a crack through both walls: the soft brazing in between walls stops the growth of a crack from one tube to the other. The eddy currents induced in the tubes are low and the Halo current flowing poloidally in the tubes exert a radial pressure which is supported by the blanket box via ad hoc supporting points provided in between first wall and blanket. Conclusions from the thermo-hydraulic analysis and the electromagnetic analysis will be presented including dynamic analysis. Also results of preliminary technological tests on coatings will be discussed

  9. The tubular separate first wall for ITER EDA

    Pizzuto, A.; Riccardi, B. [Centro Ricerche Energia Frascati, Rome (Italy); Salpietro, E. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1994-12-31

    The first wall is one of the most loaded plasma-facing components, the heat flux is such that the thermal stresses are the most important design concern. In addition, the First Wall shall resist the eddy current induced plasma disruption, the high pressure of the coolant without leaking (<10{sup {minus}6} Torr-lit/sec.) and it should maintain its properties under fast neutron flux (dose up to 3 MW/m{sup 2}). The tubular solution is the most suitable one to cope with the thermal stresses, the use of double wall reduces the risk of leaks inside the vacuum vessel by avoiding the growth of a crack through both walls: the soft brazing in between walls stops the growth of a crack from one tube to the other. The eddy currents induced in the tubes are low and the Halo current flowing poloidally in the tubes exert a radial pressure which is supported by the blanket box via ad hoc supporting points provided in between first wall and blanket. Conclusions from the thermo-hydraulic analysis and the electromagnetic analysis will be presented including dynamic analysis. Also results of preliminary technological tests on coatings will be discussed.

  10. Remote panoramic radiography of small diameter tubular butt welds

    The application of low energy isotopes has been considered for the radiographic inspection of tubular butt welds in small diameter thin walled heat exchanger tubing. Four isotopes were selected from an initial list, after consideration of gamma ray energy spectrum, half life, specific activity, availability and cost. The experimental work undertaken to assess image contrast, inherent unsharpness and weld image sensitivity is briefly discussed and the relative insensitivity of conventional British Standard wire type image quality indicators to changes in radiographic definition is demonstrated. A design study undertaken to identify a suitable remote delivery/positioning system for panoramic radiography is also reported. This system is based upon conventional projection equipment with a flexible guide tube and inflatable source positioning device, which can incorporate a suitable image quality indicator. The equipment should prove capable of greatly extending the application of panoramic radiography during heat exchanger manufacture, particularly in situations where geometric restrictions limit the application of ultrasonic techniques, or where clarification of ultrasonic defect indication is required. Thus the system will provide a useful addition to the NDE techniques currently available for the implementation of the stringent quality assurance requirements of the nuclear industry. (author)

  11. Fabrication of a molecularly imprinted polymer immobilized membrane with nanopores and its application in determination of β2-agonists in pork samples.

    Qiu, Xiuzhen; Xu, Xian-Yan; Liang, Yong; Hua, Yongbiao; Guo, Huishi

    2016-01-15

    In this paper, a method for the synthesis of ractopamine molecularly imprinted polymers (MIPs) nanotube membranes on anodic alumina oxide (AAO) nanopore surface by atom transfer radical polymerization (ATRP) was presented, in which methacrylic acid (MAA) was selected as functional monomer with a polymerization rate of 1:6 between ractopamine and MAA by the computational investigations. The morphology of MIPs nanotube membranes characterized by scanning electron microscope (SEM) suggested a well growth in the AAO nanopore surface. A series of adsorption experiments revealed that the MIPs nanotube membranes showed better extraction capacity and good selectivity for ractopamine and its analogues than that of non-imprinted polymers (NIPs) nanotube membranes. In order to evaluate the usability of the MIPs nanotube membranes, a methodology by combining MIPs nanotube membranes extraction couple with high performance liquid chromatography (HPLC) detection for the determination of β2-agonists in complex samples was developed. The linear ranges were 10-1000 μg/L for ractopamine, 100-1000 μg/L for clenbuterol, epinephrine and dopamine, and 200-1000 μg/L for terbutaline. The detection limits were within the range of 0.074-0.25 μg/L and the RSDs (n=3) were from 2.8% to 4.3%. The method was successfully applied to the analysis of β2-agonists in spiked real samples, The recoveries of all the β2-agonists at the two concentration levels were found to be within the range of 86.3-97.0% and 82.8-95.7%, respectively. The RSDs were within 2.7-5.7%. The results demonstrated that the proposed method is very suitable for the determination of β2-agonists in pork samples. PMID:26709022

  12. Behaviour of steel tubular stub and slender columns filled with concrete using recycled aggregates

    E K Mohanraj; Kandasamy, S.; Malathy, R

    2011-01-01

    This paper is based on a study that was done by utilising construction and demolition debris that had been effectively recycled, in structural members. The steel tubular columns were filled with different types of waste material, as well as recycled aggregate concrete, instead of normal conventional concrete. The results were subsequently analysed. The behaviour of circular and square concrete-filled steel tubular sections (CFSTs) under axial load, in which coarse aggregate had been partially...

  13. Strength of Tubular Joints Made by Electromagnetic Compression at Quasistatic and Cyclic Loading

    Barreiro, P.; Beerwald, C.; Homberg, W.; Kleiner, M.; Löhe, D.; Marré, M.; Schulze, V.

    2006-01-01

    Electromagnetic compression of tubular profiles with high electrical conductivity is an innovative joining process for lightweight structures. The components are joined using pulsed magnetic fields which apply radial pressures of up to 200 MPa to tubular workpieces, causing a symmetric reduction of the diameter with typical strain rates of up to 10^4 sec^(-1). This process avoids any surface damage of the workpiece because there is no contact between component and forming tool. The strength o...

  14. Experimental and numerical investigation of expandable tubular structural integrity for well applications

    T. Pervez

    2010-01-01

    Purpose: The ever-increasing energy demand has forced researchers to search for new and cheaper solutions for oil and gas production. The recent development of solid expandable tubulars (SETs) has resulted in design of slim oil and gas wells. The large plastic deformation experienced by the tubular under down-hole environment may result in premature and unexpected failures. The objective of this research is to investigate the structural integrity of SET for well applications to avoid such fai...

  15. Safety analysis of an in-service tubular reactor in high pressure polyethylene plant

    Liu Cengdian (East China University of Chemical Technology, Shanghai (China)); Zhu Lei; Wang Yinpei; Tao Xiaoya; Zhang Xiaohu; Wu Xiaodong (General Machinery Research Inst., Heifei (China)); Bao Xingfang; Qiu Renxing; Li Guopei; Xie Yonglin (Shanghai Petro-Chemical Complex (China))

    1992-01-01

    In the present study, the safety of a tubular reactor which has been used for eleven years was investigated. It has been concluded that if the material used for the tube has high fracture toughness and low fatigue crack growth rate, the release of compressive residual stress will not influence the safety operation of the tubular reactor in service. Some proposals were given for the in-service safety analysis of the reactors. (orig.).

  16. FULL-FRONTAL COLLISION SIMULATIONS AND ANALYSES OF TUBULAR SPACE FRAME BODYWORK FOR SEDAN CAR

    Huang Xiangdong; Chen Jinhua; Xie Yuecong; Giorgio Rizzoni

    2003-01-01

    Using CAE tools based on nonlinear finite element methods, full-frontal collision dynamic simulation and analysis of a sedan car body with 3D tubular loadbearing frame are tentatively carried out. Time histories of the main collisional parameters are presented, improvements of the frame are partially made according to simulation results. Collisional simulation of the tubular frame alone indicates that, such new type of bodywork for sedan car is of good potentialities to meet the collision safety regulations.

  17. Hypokalemic quadriparesis and rhabdomyolysis as a rare presentation of distal renal tubular acidosis.

    Ahmad Bhat, Manzoor; Ahmad Laway, Bashir; Mustafa, Farhat; Shafi Kuchay, Mohammad; Mubarik, Idrees; Ahmad Palla, Nazir

    2014-01-01

    Distal renal tubular acidosis is a syndrome of abnormal urine acidification and is characterized by hyperchloremic metabolic acidosis, hypokalemia, hypercalciurea, nephrocalcinosis and nephrolithiasis. Despite the presence of persistent hypokalemia, acute muscular paralysis is rarely encountered in males. Here, we will report an eighteen year old male patient who presented with flaccid quadriparesis and was subsequently found to have rhabdomyolysis, severe short stature, skeletal deformities and primary distal renal tubular acidosis. PMID:25250276

  18. Fiber beam model for fire response simulation of axially loaded concrete filled tubular columns

    Ibáñez Usach, Carmen; Romero, Manuel L.; Hospitaler Pérez, Antonio

    2013-01-01

    This paper presents a fiber beam model for the fire response simulation of concrete filled tubular columns of circular section under concentric axial load. The model consists of two parallel components, one with a circular tubular steel section, and the other with a solid circular concrete section. The components interact with nonlinear longitudinal and transverse links at the end nodes. The element is formulated on a system without rigid body modes and accounts for large displacement geometr...

  19. A new tubular graphene form of a tetrahedrally connected cellular structure.

    Bi, Hui; Chen, I-Wei; Lin, Tianquan; Huang, Fuqiang

    2015-10-21

    3D architectures constructed from a tubular graphene network can withstand repeated >95% compression cycling without damage. Aided by intertubular covalent bonding, this material takes full advantage of the graphene tube's unique attributes, including complete pre- and post-buckling elasticity, outstanding electrical conductivity, and extraordinary physicochemical stability. A highly connected tubular graphene will thus be the ultimate, structurally robust, ultrastrong, ultralight material. PMID:26305918

  20. Macrophage Matrix Metalloproteinase-9 Mediates Epithelial-Mesenchymal Transition in Vitro in Murine Renal Tubular Cells

    Tan, Thian Kui; Zheng, Guoping; Hsu, Tzu-Ting; Wang, Ying; Lee, Vincent W.S.; Tian, Xinrui; Wang, Yiping; Cao, Qi; Wang, Ya; Harris, David C H

    2010-01-01

    As a rich source of pro-fibrogenic growth factors and matrix metalloproteinases (MMPs), macrophages are well-placed to play an important role in renal fibrosis. However, the exact underlying mechanisms and the extent of macrophage involvement are unclear. Tubular cell epithelial−mesenchymal transition (EMT) is an important contributor to renal fibrosis and MMPs to induction of tubular cell EMT. The aim of this study was to investigate the contribution of macrophages and MMPs to induction of t...

  1. Effect of cisplatin on renal haemodynamics and tubular function in the dog kidney

    Daugaard, G; Abildgaard, U; Holstein-Rathlou, N H;

    1987-01-01

    Administration of cisplatin (5 mg/kg) to dogs results in polyuric renal failure due initially to a proximal tubular functional impairment. 48-72 h after the cisplatin administration the depressed renal function can be attributed to impairment of proximal as well as distal tubular reabsorptive...... capacities associated with increased renal vascular resistance. The polyuria seems to be due to the impaired reabsorption rate in the distal nephron segments....

  2. Linear tubular switched reluctance motor for heart assistance circulatory: Analytical and finite element modeling

    LLIBRE, Jean-François; Martinez, Nicolas; Nogarède, Bertrand; Leprince, Pascal

    2011-01-01

    A linear tubular switched reluctance motor is presented. This actuator is devoted to be used as a left ventricular assist device (LVAD). In order to avoid thrombosis, this actuator includes pump and valve functions. By using a St. Jude Medical mechanical valve inside the tubular mover, a pulsatile flow is created in the descending aorta. A linear model of a basic pattern of the actuator based on a reluctance network is developed. Then, a two dimensions finite element method analysis is per...

  3. Characterization of segregation in a tubular polymerization reactor by a new chemical method

    Meyer, T; Renken, A.

    1990-01-01

    Micromixing in a tubular polymn. reactor is characterized by the mol. wt. of polystyrene obtained in the presence of a chain transfer agent. Monomer and the transfer agent are fed sep. into the reactor. For const. overall inlet concns., the mean mol. wt. produced is strongly dependent on mixing intensity. Expts. were carried out in a pilot plant loop tubular reactor of different configurations and monomer conversions ?80%. The degree of segregation as a function of energy dissipation and the ...

  4. Tubular cell phenotype in HIV-associated nephropathy: role of phospholipid lysophosphatidic acid.

    Ayasolla, Kamesh R; Rai, Partab; Rahimipour, Shai; Hussain, Mohammad; Malhotra, Ashwani; Singhal, Pravin C

    2015-08-01

    Collapsing glomerulopathy and microcysts are characteristic histological features of HIV-associated nephropathy (HIVAN). We have previously reported the role of epithelial mesenchymal transition (EMT) in the development of glomerular and tubular cell phenotypes in HIVAN. Since persistent tubular cell activation of NFκB has been reported in HIVAN, we now hypothesize that HIV may be contributing to tubular cell phenotype via lysophosphatidic acid (LPA) mediated downstream signaling. Interestingly, LPA and its receptors have also been implicated in the tubular interstitial cell fibrosis (TIF) and cyst formation in autosomal dominant polycystic kidney disease (PKD). Primary human proximal tubular cells (HRPTCs) were transduced with either empty vector (EV/HRPTCs), HIV (HIV/HRPTCs) or treated with LPA (LPA/HRPTC). Immunoelectrophoresis of HIV/HRPTCs and LPA/HRPTCs displayed enhanced expression of pro-fibrotic markers: a) fibronectin (2.25 fold), b) connective tissue growth factor (CTGF; 4.8 fold), c) α-smooth muscle actin (α-SMA; 12 fold), and d) collagen I (5.7 fold). HIV enhanced tubular cell phosphorylation of ILK-1, FAK, PI3K, Akt, ERKs and P38 MAPK. HIV increased tubular cell transcriptional binding activity of NF-κB; whereas, a LPA biosynthesis inhibitor (AACOCF3), a DAG kinase inhibitor, a LPA receptor blocker (Ki16425), a NF-κB inhibitor (PDTC) and NFκB-siRNA not only displayed downregulation of a NFκB activity but also showed attenuated expression of profibrotic/EMT genes in HIV milieu. These findings suggest that LPA could be contributing to HIV-induced tubular cell phenotype via NFκB activation in HIVAN. PMID:26079546

  5. Design and performance of tubular flat-plate solid oxide fuel cell

    Matsushima, T.; Ikeda, D.; Kanagawa, H. [NTT Integrated Information & Energy Systems Labs., Tokyo (Japan)] [and others

    1996-12-31

    With the growing interest in conserving the environmental conditions, much attention is being paid to Solid Oxide Fuel Cell (SOFC), which has high energy-conversion efficiency. Many organizations have conducted studies on tubular and flat type SOFCs. Nippon Telegraph and Telephone Corporation (NTT) has studied a combined tubular flat-plate SOFC, and already presented the I-V characteristics of a single cell. Here, we report the construction of a stack of this SOFC cell and successful generation tests results.

  6. Construção e avaliação de um eletrodo tubular sensível ao íon hidrogênio como detector em sistemas de análise em fluxo

    Martelli Patrícia B.

    1998-01-01

    Full Text Available The construction of a tubular hydrogen ion-selective potentiometric electrode without inner reference solution, based on the tridodecylamine (TDDA ionophore, and its evaluation in a flow system are described. TDDA was dissolved in 2-nitrophenyl octyl ether, dispersed in a PVC membrane and applied directly to a conducting support which consisted of an epoxy resin and graphite mixture. The electrode was designed with a tubular geometry to effort facilities to be coupled as part of a flow injection network. The main working characteristics such as response time, linear pH range, selectivity and life time were evaluated and compared with those obtained which a conventionally shaped electrode based on the same sensor. The electrode showed a slope of 51-52 mV dec-1 within a linear pH range from 4.0 up to 12.0.

  7. Cadmium and cisplatin damage erythropoietin-producing proximal renal tubular cells

    Horiguchi, Hyogo; Oguma, Etsuko; Kayama, Fujio [Jichi Medical School, Division of Environmental Medicine, Center for Community Medicine, Tochigi (Japan); Core Research for Evolutional Science and Technology, Japan Science Technology Corporation (CREST-JST), Saitama (Japan)

    2006-10-15

    The concomitant manifestations of proximal renal tubular dysfunction and anemia with erythropoietin (Epo) deficiency observed in chronic cadmium (Cd) intoxication, such as Itai-itai disease, suggest a close local correlation between the Cd-targeted tubular cells and Epo-producing cells in the kidney. Therefore, we investigated the local relationship between hypoxia-induced Epo production and renal tubular injury in rats injected with Cd at 2 mg/kg twice a week for 8 months. Anemia due to insufficient production of Epo was observed in Cd-intoxicated rats. In situ hybridization detected Epo mRNA expression in the proximal renal tubular cells of hypoxic rats without Cd intoxication, and the Cd-intoxicated rats showed atrophy of Epo-expressing renal tubules and replacement of them with fibrotic tissue. A single dose of cisplatin at 8 mg/kg, which can induce clinical manifestations similar to those of Cd including renal tubular damage along with Epo-deficient anemia, resulted in Epo-expressing renal tubule destruction on day 4. These data indicate that Cd and cisplatin would induce anemia through the direct injury of the proximal renal tubular cells that are responsible for Epo production. (orig.)

  8. Prevalence of renal tubular dysfunction in beta thalassemia minor in shiraz

    Ali Moradi Nakhodcheri

    2012-02-01

    Full Text Available  Background & objective: β-Thalassemia minor is an asymptomatic hereditary disease. The first study on the relation of renal tubular dysfunction and β-thalassemia minor was performed in 2002 but those studies seem inadequate.The main goal of this study is through evaluation of renal tubular function in 100 patients with thalassemia minor. Materials & Methods: 100 patients with β- thalassemia which confirmed by hemoglobin electrophoresis and CBC as well as RBC indices were studied.14 out of 100 cases exit because of Urinary Tract Infection, diabetes mellitus or hypertension.Complete chemistry profile was performed on serum and urine of all reminder 86 patients (46 female and 40 male. Patients classified into two groups: β-thalassemia minor with anemia and without anemia. Another control group include 50 healthy individuals also considered.Then data analyzed by proper statistical methods. Results: 20 out of 86 reminder cases e.g. 24% showed at least one index of renal tubular dysfunction.58% of patients was been anemic and 42% non anemic. The most prominent tubular dysfunction was seen in a 29 years old lady with glucosuria and without anemia. conclusion: β-Thalassemia minor is common in Iran specially in Fars province. This study revealed significant renal tubular dysfunction in patient with β-thalassemia minor. So it is necessary to check out thalassemic patients for renal function tests periodically. Key words: β-thalassemia, minor,renal tubular dysfunction

  9. Ground Vibration Isolation of Multiple Scattering by Using Rows of Tubular Piles as Barriers

    Miao-miao Sun

    2014-01-01

    Full Text Available A new formal solution for the multiple scattering of plane harmonic waves by a group of arbitrary configuration tubular piles in an elastic total space is derived. Each order of scattering satisfies prescribed boundary conditions at the interface of tubular piles, which is delivered as the sum of incident and scattering waves. The first order performs the scattering wave by each scattered pile and the subsequent orders resulted from the excitation of each pile of first order of scattering from the remaining tubular piles. Advanced scattering orders can be regarded as the same manners. Several series of scattering coefficients are figured out with the aids of addition theorem so that the exact steady-state solution for the scattered displacement and stress is obtained. Particularly, when internal diameter of tubular piles tends to be infinitely small, it degenerates to a solid pile problem. By imposing the normalized displacement amplitudes and transmissibility indices, the influences of specific parameters such as scattering orders, internal and external diameter ratio of piles, pile material rigidity, position and distances between tubular pile and pile rows, and pile numbers are discussed. Certain recommended conclusions have been drawn as the guidelines of practical engineering design for discontinuous barrier of tubular piles.

  10. Axionic membranes

    Aurilia, A. (Dept. of Physics, California State Polytechnic Univ., Pomona, CA (United States)); Spallucci, E. (Dipt. di Fisica Teorica, Univ. Trieste (Italy) INFN, Sezione Trieste (Italy))

    1992-05-21

    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{sub {mu}{nu}}(x) and the ring by a closed string. The interaction between the B{sub {mu}{nu}} 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.).

  11. Analysis and Counter-measures of the AAO Technological Process with Acid Effluent%AAO工艺出水pH值偏酸问题分析及对策

    李金浩

    2009-01-01

    某污水处理厂AAO工艺出水存在着pH值偏低的问题.通过对比历史数据和缺氧反硝化试验,研究了以进厂污水作为碳源的反硝化脱氮的能力及碳氮比对脱氮的影响,并通过碱度平衡核算,分析了硝化和反硝化段的情况,查找出了出水碱度不足pH偏酸的原因,提出了快捷、行之有效的控制方案.%This paper analyzes the anoxic/anaerobic/aerobic process(AAO)technological process with acid pH Value of effluent.By comparing recorded data and anoxic de-nitrification test,it studies the de-nitrification capability of sewage as carbon source,as well as how the carbon and nitrogen affect the de-nitrification capability.Through assessing the alkalinity balance accounting,the situation of nitrification and de-nitrification was analyzed,to figure out why the pH Value is to be acid.Finally,practicable schemes tO control the pH Value Were presented.

  12. Application of ceramic membranes for seawater reverse osmosis (SWRO) pre-treatment

    Hamad, Juma

    2013-05-30

    Low-pressure (microfiltration/ultrafiltration (MF/UF)) membranes are being increasingly used as pre-treatment, prior to seawater reverse osmosis (SWRO). The objective of pre-treatment before reverse osmosis (RO) membranes is to remove undesirable and particulate fouling materials (algae, suspended and colloidal particles). Also, a pre-treatment barrier reduces organics and provides better feed water quality for RO membranes. MF and UF pre-treatment prior to SWRO provides Low Silt Density Index (SDI) values recommended for RO operation. Ceramic membranes are more attractive as they made of more chemically resistant materials, which allow for more stable operation and aggressive backwashing (BW) and cleaning. A pilot plant with a monolith ceramic MF membrane (0.1 μm pore size) from METAWATER was used to carry out the study. Red Sea water pumped from a distance of 700 m offshore from Thuwal (Kingdom of Saudi Arabia) was used as feed water. The pilot plant was operated automatically at constant flux of 150 LMH that involved BW, air flushing and forward flushing at the end of filtration cycle. Seawater permeates were used for hydraulic BW, while sodium hypochlorite, citric acid and sodium hydroxide were used for chemical cleaning (CIP) to restore the membrane permeability after use. Filtration cycles of 2.5 h were adopted for initial experiments. Aggressive BW flux of 1,800 LMH for 15 s, air flushing of 4 bars for 10 s and forward flushing of 300 LMH for 40 s were applied for regular membrane hydraulic cleaning. The increase of membrane resistances over time was monitored. Further studies were also performed by using Anopore ceramic membranes AAO100 (pore sizes of 0.1 μm) using a constant pressure bench-scale set-up. The feed water and permeate were analysed using an SDI unit, flow cytometre (FCM) and liquid chromatography with organic carbon detection (LC-OCD). The results showed that ceramic membrane filtration reduced the SDI15 of seawater from 6.1 to 2.1 which

  13. Multicomponent Transport through Realistic Zeolite Membranes: Characterization & Transport in Nanoporous Networks

    William C. Conner

    2007-08-02

    These research studies focused on the characterization and transport for porous solids which comprise both microporosity and mesoporosity. Such materials represent membranes made from zeolites as well as for many new nanoporous solids. Several analytical sorption techniques were developed and evaluated by which these multi-dimensional porous solids could be quantitatively characterized. Notably an approach by which intact membranes could be studied was developed and applied to plate-like and tubular supported zeolitic membranes. Transport processes were studied experimentally and theoretically based on the characterization studies.

  14. Un modelo descriptivo del sistema reproductor hembra del coipo (Myocastor coypus II: los órganos tubulares (A descriptive model of the female reproductive system of coypu (Myocastor coypus II: tubular organs

    Felipe, A. E.

    2006-03-01

    prominence. The mucous tunic of infundibulum and ampulla had many longitudinal folds with fine secondary and tertiary branches. Folds were low and undivided at the isthmus. The mucosa of the oviducts was covered by high epithelium. The double uterus consisted of two uteri with cavities quite independent from each other. A gross septum separated the cervical canals which still remained separately in the dorsal surface of the cervix. The mucous epithelium of the horns was composed of ciliated cylindrical cells that contained oval nuclei in basal position. There were abundant endometrial glands in the horns. The epithelium of the endocervix was composed of large columnar cells, with a mucus-secreting appearance. All along the uterine horns the lamina propria was composed of a lax connective tissue. The myometrium was very well-developed. The perimetrium was a serous membrane with many longitudinal muscle fibres. The vagina was a tubular organ. The fornix was divided into five cul-de-sacs. The vaginal mucosa was covered by a stratified squamous epithelium. The connective-epithelial junction was notably irregular due to the presence of many connective papillae which projected themselves from the lamina propria into the basal epithelium. The general morphology of the reproductive organs of the Myocastor coypus is typical of the hystricomorph rodents studied.

  15. Effect of Air Flow on Tubular Solar Still Efficiency

    Arunkumar Thirugnanasambantham

    2013-04-01

    Full Text Available An experimental work was reported to estimate the increase in distillate yield for a compound parabolic concentrator-concentric tubular solar still (CPC-CTSS. The CPC dramatically increases the heating of the saline water. A novel idea was proposed to study the characteristic features of CPC for desalination to produce a large quantity of distillate yield. A rectangular basin of dimension 2 m × 0.025 m × 0.02 m was fabricated of copper and was placed at the focus of the CPC. This basin is covered by two cylindrical glass tubes of length 2 m with two different diameters of 0.02 m and 0.03 m. The experimental study was operated with two modes: without and with air flow between inner and outer tubes. The rate of air flow was fixed throughout the experiment at 4.5 m/s. On the basis of performance results, the water collection rate was 1445 ml/day without air flow and 2020 ml/day with air flow and the efficiencies were 16.2% and 18.9%, respectively.Findings:The experimental study was operated with two modes: without and with air flow between inner and outer tubes. The rate of air flow was fixed throughout the experiment at 4.5 m/s.Conclusions:On the basis of performance results, the water collection rate was 1445 ml/day without air flow and 2020 ml/day with air flow and the efficiencies were 16.2% and 18.9%, respectively.

  16. Design, construction and evaluation of solarized airlift tubular photobioreactor

    Bahadur, A.; Zubair, M.; Khan, M. B.

    2013-06-01

    An innovative photobioreactor is developed for growing algae in simulated conditions. The proposed design comprises of a continuous tubular irradiance loop and air induced liquid circulation with gas separation through air lift device. The unique features of air lift system are to ensure the shear free circulation of sensitive algal culture and induce light/dark cycles to the photosynthetic micro-organisms. The design strategy employs to model and construct a 20-liter laboratory scale unit using Boro-silicate glass tubing. The material is selected to ensure maximum photon transmission. All components of the device are designed to have flexibility to be replaced with an alternative design, providing fair chance of modification for future investigators. The principles of fluid mechanics are applied to describe geometrical attributes of the air lift system. Combination of LEDs and Florescent tube lights (Warm white) were used to illuminate the photosynthesis reaction area providing a possibility to control both illumination duration and light intensity. 200 Watt Solar PV system is designed to power up the device which included air pump (100 Watt) and illumination system (100 Watt). Algal strain Chlorella sp was inoculated in photobioreactor which was sparged with air and carbon dioxide. The growth was sustained in the batch mode with daily monitoring of temperature, pH and biomass concentration. The novel photobioreactor recorded a maximum experimental average yield of 0.65 g/l.day (11.3 g/m2.day) as compared to theoretical modeled yield of 0.82 g/l.day (14.26 g/m2.day), suggesting the device can be efficiently and cost-effectively employed in the production of algal biomass for biofuels, concomitantly mitigating CO2.

  17. Design, construction and evaluation of solarized airlift tubular photobioreactor

    An innovative photobioreactor is developed for growing algae in simulated conditions. The proposed design comprises of a continuous tubular irradiance loop and air induced liquid circulation with gas separation through air lift device. The unique features of air lift system are to ensure the shear free circulation of sensitive algal culture and induce light/dark cycles to the photosynthetic micro-organisms. The design strategy employs to model and construct a 20-liter laboratory scale unit using Boro-silicate glass tubing. The material is selected to ensure maximum photon transmission. All components of the device are designed to have flexibility to be replaced with an alternative design, providing fair chance of modification for future investigators. The principles of fluid mechanics are applied to describe geometrical attributes of the air lift system. Combination of LEDs and Florescent tube lights (Warm white) were used to illuminate the photosynthesis reaction area providing a possibility to control both illumination duration and light intensity. 200 Watt Solar PV system is designed to power up the device which included air pump (100 Watt) and illumination system (100 Watt). Algal strain Chlorella sp was inoculated in photobioreactor which was sparged with air and carbon dioxide. The growth was sustained in the batch mode with daily monitoring of temperature, pH and biomass concentration. The novel photobioreactor recorded a maximum experimental average yield of 0.65 g/l.day (11.3 g/m2.day) as compared to theoretical modeled yield of 0.82 g/l.day (14.26 g/m2.day), suggesting the device can be efficiently and cost-effectively employed in the production of algal biomass for biofuels, concomitantly mitigating CO2.

  18. Study of carrier mobility of tubular and planar graphdiyne

    Jalili, Seifollah; Houshmand, Fatemeh; Schofield, Jeremy

    2015-05-01

    Graphdiyne nanotubes were constructed 10 years after their theoretical prediction and many properties of them have remained unknown until now. In this investigation, transport properties of new family of carbon nanotubes, graphdiyne nanotubes, were studied systematically by using spin-polarized density functional theory coupled with Boltzmann transport equation with relaxation time approximation. We have predicted the charge mobility for tubular forms of graphdiyne (GDNT). The calculated intrinsic electron mobility for GDNT at room temperature can reach the order of 104 cm2 V-1 s-1. On the other hand, the hole mobility magnitude is about an order of 102 cm2 V-1 s-1. The DFT results also show that GDNT is direct band-gap semiconductor. The calculated cohesive and strain energies for GDNT indicate that this new nanomaterial is more stable than the conventional carbon nanotubes. Adsorption of a transition metal atom (Fe) on the external surface of GDNT has been studied by DFT method as well as density functional theory plus effective on-site Coulomb repulsion parameters U, Hubbard correction. Transition metal (TM)-adsorbed GDNT is magnetic and shows semimetal property. Charge transfer between TM adatom and GDNT as well as the electron redistribution of the TM intra-atomic s, p and d orbitals indicates that the TM-adsorbed single-walled γ-graphdiyne have a high potential for applications in spintronics and in future optoelectronics. The single-layer nanostructure of graphdiyne (pGD) is studied too. The resulted electronic properties of pGD and TM-absorbed-pGD confirm previous results for these nanostructures. Also, transport properties of stable TM-pGD nanostructure as well as TM-GDNT are notable. Energy gap values for both nanostructures are found to be strongly sensitive to the local Coulomb interactions U of the TM d orbitals.

  19. Robotic membranes

    Ramsgaard Thomsen, Mette

    2008-01-01

    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...

  20. A selective and sensitive stability-Indicating HPLC method for the validated assay of etoposide from commercial dosage form and polymeric tubular nanocarriers.

    Algan, Aslihan Hilal; Gumustas, Mehmet; Karatas, Aysegul; Ozkan, Sibel A

    2016-05-30

    Etoposide is a topoisomerase II enzyme inhibitor type chemotherapeutic agent which is widely used in the therapy of various cancers. Its short half-life and toxicity to normal tissues are the major drawbacks in its clinical applications. Polymeric nanoparticulate drug delivery systems are rational carriers to deliver etoposide with higher efficiency and fewer side effects. In addition tubular shaped drug carriers are found to show a great potential for drug delivery on the basis of promising results regarding particle shape and cellular uptake. In this study, etoposide loaded polymeric tubular nanocarriers have been developed by template wetting method using porous anodic aluminum oxide membranes as templates. The developed poly(methyl methacrylate) nanocarriers were evaluated for structural analysis, in vitro drug release studies and drug release kinetics. Accurate and reliable determination of the drug release from newly developed nanocarriers, is of great importance. For this reason a selective and sensitive reversed phase liquid chromatography method was developed and fully validated from the point of system suitability, specificity, linearity and range, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and robustness for the reliable determination of etoposide. Stability indicating capability was shown with forced degradation studies and the chromatographic conditions were optimized on ACE 5C18 (150mm×4.6mm I.D., 5μm) analytical column. Related to the calibration results ETP was found linear in the range between 0.2 from 100μgmL(-1) with the LOD as 0.015μg.mL(-1). The resultant conditions were applied for the selective and sensitive determination of etoposide from its commercial dosage form with the high accuracy values (99.82-100.65%). The method was successfully detected assay of etoposide release from newly developed polymeric tubular nanocarriers, which was found as 72.2% at the end of 24h. PMID:26971031

  1. Identification of genomic biomarkers for concurrent diagnosis of drug-induced renal tubular injury using a large-scale toxicogenomics database

    Drug-induced renal tubular injury is one of the major concerns in preclinical safety evaluations. Toxicogenomics is becoming a generally accepted approach for identifying chemicals with potential safety problems. In the present study, we analyzed 33 nephrotoxicants and 8 non-nephrotoxic hepatotoxicants to elucidate time- and dose-dependent global gene expression changes associated with proximal tubular toxicity. The compounds were administered orally or intravenously once daily to male Sprague-Dawley rats. The animals were exposed to four different doses of the compounds, and kidney tissues were collected on days 4, 8, 15, and 29. Gene expression profiles were generated from kidney RNA by using Affymetrix GeneChips and analyzed in conjunction with the histopathological changes. We used the filter-type gene selection algorithm based on t-statistics conjugated with the SVM classifier, and achieved a sensitivity of 90% with a selectivity of 90%. Then, 92 genes were extracted as the genomic biomarker candidates that were used to construct the classifier. The gene list contains well-known biomarkers, such as Kidney injury molecule 1, Ceruloplasmin, Clusterin, Tissue inhibitor of metallopeptidase 1, and also novel biomarker candidates. Most of the genes involved in tissue remodeling, the immune/inflammatory response, cell adhesion/proliferation/migration, and metabolism were predominantly up-regulated. Down-regulated genes participated in cell adhesion/proliferation/migration, membrane transport, and signal transduction. Our classifier has better prediction accuracy than any of the well-known biomarkers. Therefore, the toxicogenomics approach would be useful for concurrent diagnosis of renal tubular injury.

  2. Copper deposition on Pd membranes by electroless plating

    Acha, E.; Arias, P.L.; Cambra, J.F. [Chemical Engineering and Environmental Department, University of the Basque Country, UPV/EHU, 48013 Bilbao (Spain); Van Delft, Y.; Overbeek, J. [Energy Research Centre of the Netherlands ECN, Petten (Netherlands)

    2011-10-15

    PdCu membranes were prepared by the electroless plating of Pd membranes prepared on ceramic tubular supports. Different PdCu membranes were prepared with Pd content between 45 and 77 wt% and a total metal layer between 0.5 and 1.9 {mu}m thickness. The alloying step was performed in two ways to compare and establish the required alloying time for obtaining high permeance membranes. The alloying was analysed with EDX composition measurements, and full alloying was not required to obtain a stable hydrogen flux. Finally, permeance tests were performed at different pressures, including temperature cycles in hydrogen and nitrogen, to observe membrane stability. The hydrogen permeance values of the membranes were high, between 1.5x10{sup -3} and 4.5x10{sup -3} mol/(s Pa{sup 0.5} m{sup 2}) at 673 K. The membranes recorded stable permeance values even after thermal cycles in a hydrogen atmosphere. Metal layer thickness was calculated using both the weight difference method and SEM images. SEM images were also used to analyse the surface morphology of the membranes, which was generally fairly uniform and smooth.

  3. Oxygen Transport Membranes

    S. Bandopadhyay

    2008-08-30

    small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume

  4. Mitochondrial outer membrane forms bridge between two mitochondria in Arabidopsis thaliana.

    Yamashita, Akihiro; Fujimoto, Masaru; Katayama, Kenta; Tsutsumi, Nobuhiro; Arimura, Shin-Ichi

    2016-05-01

    Mitochondria are double-membrane organelles that move around and change their shapes dynamically. In plants, the dynamics of the outer membrane is not well understood. We recently demonstrated that mitochondria had tubular protrusions of the outer membrane with little or no matrix, called MOPs (mitochondrial outer-membrane protrusions; MOPs). Here we show that a MOP can form a bridge between two mitochondria in Arabidopsis thaliana. The bridge does not appear to involve the inner membranes. Live imaging revealed stretching of the MOP bridge, demonstrating the flexibility of the outer membrane. Mitochondria frequently undergo fission and fusion. These observations raise the possibility that MOPs bridges have a role in these processes. PMID:27031262

  5. Experimental and numerical investigation of expandable tubular structural integrity for well applications

    T. Pervez

    2010-07-01

    Full Text Available Purpose: The ever-increasing energy demand has forced researchers to search for new and cheaper solutions for oil and gas production. The recent development of solid expandable tubulars (SETs has resulted in design of slim oil and gas wells. The large plastic deformation experienced by the tubular under down-hole environment may result in premature and unexpected failures. The objective of this research is to investigate the structural integrity of SET for well applications to avoid such failures.Design/methodology/approach: In order to achieve the objectives, simulation work was carried out using finite element method and experimental tests were conducted on full size tubular for validation of numerical results.Findings: The required drawing force for expansion under different expansion ratios, surplus deformation, variations in tubular thickness and length were estimated numerically and experimentally. The differences in values using two approaches vary from 5% to 12%. Tubular wall thickness decreases as the mandrel angle, expansion ratio, and friction coefficient increase.Research limitations/implications: The issue of maximum expansion a tubular can be subjected to needs to be further investigated. Furthermore, the pre and post-expansion material properties need immediate attention of researchers to fulfil the dream of low-cost expandable solution.Practical implications: In recent years, solid expandable tubular technology has already made significant inroads in replacing conventional telescopic oil wells. It allows design and realization of slim wells, accessing difficult and ultra-deep reservoirs, well remediation, zonal isolation, drilling of directional and horizontal wells, etc.Originality/value: SET is an emerging technology for oil and gas industry. The current findings are very valuable for researchers and well engineers to design slim wells and enhance the productivity of older wells.

  6. The influence of polymeric membrane gas spargers on hydrodynamics and mass transfer in bubble column bioreactors.

    Tirunehe, Gossaye; Norddahl, B

    2016-04-01

    Gas sparging performances of a flat sheet and tubular polymeric membranes were investigated in 3.1 m bubble column bioreactor operated in a semi batch mode. Air-water and air-CMC (Carboxymethyl cellulose) solutions of 0.5, 0.75 and 1.0 % w/w were used as interacting gas-liquid mediums. CMC solutions were employed in the study to simulate rheological properties of bioreactor broth. Gas holdup, bubble size distribution, interfacial area and gas-liquid mass transfer were studied in the homogeneous bubbly flow hydrodynamic regime with superficial gas velocity (U G) range of 0.0004-0.0025 m/s. The study indicated that the tubular membrane sparger produced the highest gas holdup and densely populated fine bubbles with narrow size distribution. An increase in liquid viscosity promoted a shift in bubble size distribution to large stable bubbles and smaller specific interfacial area. The tubular membrane sparger achieved greater interfacial area and an enhanced overall mass transfer coefficient (K La) by a factor of 1.2-1.9 compared to the flat sheet membrane. PMID:26857370

  7. Genome-wide profiling to analyze the effects of FXR activation on mouse renal proximal tubular cells

    Gui, Ting; Gai, Zhibo

    2015-01-01

    To assess the effect of farnesoid X receptor (FXR), a bile acid nuclear receptor, on renal proximal tubular cells, primary cultured mouse kidney proximal tubular cells were treated with GW4064 (a FXR agonist) or DMSO (as controls) overnight. Analysis of gene expression in the proximal tubular cells by whole genome microarrays indicated that FXR activation induced genes involved in fatty acid degradation and oxidation reduction. Among them, genes involved in glutathione metabolism were mostly ...

  8. 管式反渗透浓缩牛奶的实验研究%Study on concentration of milk by tubular reverse osmosis

    吕建国; 张鹏

    2011-01-01

    介绍了采用管式反渗透膜浓缩牛奶的工艺,研究了工艺中的压力、温度、浓度和浓缩过程与牛奶中有效成分的截留率之间的关系,同时也研究了压力、温度、浓度在浓缩过程中与膜通量之间的关系.实验结果证明,管式反渗透膜对有效成分的截留率接近100%.%The tubular reverse osmosis membrane milk processing was introduced.The relationship between pressure ,temperature, concentration and retention rates of valuable components were studied.Aisc the relationship between pressure, temperature, concentration and permeate flux in concentrated process were studied with a tubular reverse osmosis module.Experimental results proved that the retention of valuable components of this system was approximation 100%.

  9. [Tubular rectum and colon resection. A new operative method for the removal of large adenomas and low-risk carcinomas].

    Gall, F P

    1982-08-01

    A new operative method for the removal of large sessile tubular or villous adenomas and small early carcinomas of the low risk type by a "tubular" colonic or rectal resection is described. The term "tubular" applies to a short segmental resection of the colon or rectum with complete preservation of the mesocolon or mesorectum and the marginal or superior hemorrhoidal artery. This tubular resection has been used by us since 1981 in 11 patients (7 adenomas, 3 adenocarcinomas and one carcinoid). There was no suture line leakage. No lethality and so far no recurrence. The advantages of this new operative technique over conventional methods are discussed in detail. PMID:7128268

  10. p-Cresol mediates autophagic cell death in renal proximal tubular cells.

    Lin, Hsin-Hung; Huang, Chiu-Ching; Lin, Tze-Yi; Lin, Ching-Yuang

    2015-04-01

    Higher serum level of p-cresol (PC) in chronic kidney disease (CKD) patients has been linked with CKD progression. The toxic effect of PC on diverse cells has been reported by prior studies, except for renal tubular cells. Both autophagy and apoptosis contribute to renal tubular cell death, yet evidence of its response to PC is limited and their crosstalk is still unclear. Autophagy is an important cellular process involved in toxin-induced cell death. Renal tubular cell death in tubular injury is thought to be one of the key events causing the progression of CKD. Thus, we treated rat (NRK-52E) and human (HRPTEC) renal proximal tubular cells (RPTC) with PC and found the cell proliferation was significantly decreased. Cell apoptosis was significantly increased and accompanied with the activation of autophagy as evidenced by increases in LC3-II, beclin 1 and Atg 4. We also found an increase of p62 by c-Jun activation. p62 accumulation could mediate the activation of caspase 8-dependent cell apoptosis. Conversely, knockdown of p62 by siRNA of p62 had the opposite effect by arresting LC3-II accumulation and promoting increasing cell viability. We conclude that PC triggered autophagic RPTC death via JNK-mediated p62 accumulation and then activated caspase 8-dependent cell death pathway. PC can be considered as one of the key events causing progression of CKD, which might affect drug disposition in CKD cases. PMID:25668154

  11. Muscle imaging in patients with tubular aggregate myopathy caused by mutations in STIM1.

    Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro; Nadaj-Pakleza, Aleksandra; Vialle, Marc; Fattori, Fabiana; Vissing, John; Ricci, Enzo; Bertini, Enrico

    2015-11-01

    Tubular aggregate myopathy is a genetically heterogeneous disease characterized by tubular aggregates as the hallmark on muscle biopsy. Mutations in STIM1 have recently been identified as one genetic cause in a number of tubular aggregate myopathy cases. To characterize the pattern of muscle involvement in this disease, upper and lower girdles and lower limbs were imaged in five patients with mutations in STIM1, and the scans were compared with two patients with tubular aggregate myopathy not caused by mutations in STIM1. A common pattern of involvement was found in STIM1-mutated patients, although with variable extent and severity of lesions. In the upper girdle, the subscapularis muscle was invariably affected. In the lower limbs, all the patients showed a consistent involvement of the flexor hallucis longus, which is very rarely affected in other muscle diseases, and a diffuse involvement of thigh and posterior leg with sparing of gracilis, tibialis anterior and, to a lesser extent, short head of biceps femoris. Mutations in STIM1 are associated with a homogeneous involvement on imaging despite variable clinical features. Muscle imaging can be useful in identifying STIM1-mutated patients especially among other forms of tubular aggregate myopathy. PMID:26255678

  12. Alpha detection in pipes using an inverting membrane scintillator

    Kendrick, D.T.; Cremer, C.D.; Lowry, W. [Science and Engineering Associates, Inc., Albuquerque, NM (United States)] [and others

    1995-10-01

    Characterization of surface alpha emitting contamination inside enclosed spaces such as piping systems presents an interesting radiological measurement challenge. Detection of these alpha particles from the exterior of the pipe is impossible since the alpha particles are completely absorbed by the pipe wall. Traditional survey techniques, using hand-held instruments, simply can not be used effectively inside pipes. Science and Engineering Associates, Inc. is currently developing an enhancement to its Pipe Explorer{trademark} system that will address this challenge. The Pipe Explorer{trademark} uses a unique sensor deployment method where an inverted tubular membrane is propagated through complex pipe runs via air pressure. The inversion process causes the membrane to fold out against the pipe wall, such that no part of the membrane drags along the pipe wall. This deployment methodology has been successfully demonstrated at several DOE sites to transport specially designed beta and gamma, scintillation detectors into pipes ranging in length up to 250 ft.

  13. Osteomalacia complicating renal tubular acidosis in association with Sjogren's syndrome.

    El Ati, Zohra; Fatma, Lilia Ben; Boulahya, Ghada; Rais, Lamia; Krid, Madiha; Smaoui, Wided; Maiz, Hedi Ben; Beji, Soumaya; Zouaghi, Karim; Moussa, Fatma Ben

    2014-09-01

    Renal involvement in Sjogren's syndrome (SS) is not uncommon and may precede other complaints. Tubulointerstitial nephritis is the most common renal disease in SS and may lead to renal tubular acidosis (RTA), which in turn may cause osteomalacia. Nevertheless, osteomalacia rarely occurs as the first manifestation of a renal tubule disorder due to SS. We herewith describe a 43-year-old woman who was admitted to our hospital for weakness, lumbago and inability to walk. X-ray of the long bones showed extensive demineralization of the bones. Laboratory investigations revealed chronic kidney disease with serum creatinine of 2.3 mg/dL and creatinine clearance of 40 mL/min, hypokalemia (3.2 mmol/L), hypophosphatemia (0.4 mmol/L), hypocalcemia (2.14 mmol/L) and hyperchloremic metabolic acidosis (chlorine: 114 mmol/L; alkaline reserve: 14 mmol/L). The serum alkaline phosphatase levels were elevated. The serum levels of 25-hydroxyvitamin D and 1,25-dihydroxy vitamin D were low and borderline low, respectively, and the parathyroid hormone level was 70 pg/L. Urinalysis showed inappropriate alkaline urine (urinary PH: 7), glycosuria with normal blood glucose, phosphaturia and uricosuria. These values indicated the presence of both distal and proximal RTA. Our patient reported dryness of the mouth and eyes and Schirmer's test showed xerophthalmia. An accessory salivary gland biopsy showed changes corresponding to stage IV of Chisholm and Masson score. Kidney biopsy showed diffuse and severe tubulo-interstitial nephritis with dense lymphoplasmocyte infiltrates. Sicca syndrome and renal interstitial infiltrates indicated SS as the underlying cause of the RTA and osteomalacia. The patient received alkalinization, vitamin D (Sterogyl ®), calcium supplements and steroids in an initial dose of 1 mg/kg/day, tapered to 10 mg daily. The prognosis was favorable and the serum creatinine level was 1.7 mg/dL, calcium was 2.2 mmol/L and serum phosphate was 0.9 mmol/L. PMID:25193912

  14. Potentialities of a Membrane Reactor with Laccase Grafted Membranes for the Enzymatic Degradation of Phenolic Compounds in Water

    Vorleak Chea

    2014-10-01

    Full Text Available This paper describes the degradation of phenolic compounds by laccases from Trametes versicolor in an enzymatic membrane reactor (EMR. The enzymatic membranes were prepared by grafting laccase on a gelatine layer previously deposited onto α-alumina tubular membranes. The 2,6-dimethoxyphenol (DMP was selected  from among the three different phenolic compounds tested (guaiacol, 4-chlorophenol and DMP to study the performance of the EMR in dead end configuration. At the lowest feed substrate concentration tested (100 mg·L−1, consumption increased with flux (up to 7.9 × 103 mg·h−1·m−2 at 128 L·h−1·m−2, whereas at the highest substrate concentration (500 mg·L−1, it was shown that the reaction was limited by the oxygen content.

  15. Dynamic sorting of lipids and proteins in membrane tubes with a moving phase boundary

    Heinrich, Michael; Tian, Aiwei; Esposito, Cinzia; Baumgart, Tobias

    2010-01-01

    Cellular organelle membranes maintain their integrity, global shape, and composition despite vigorous exchange among compartments of lipids and proteins during trafficking and signaling. Organelle homeostasis involves dynamic molecular sorting mechanisms that are far from being understood. In contrast, equilibrium thermodynamics of membrane mixing and sorting, particularly the phase behavior of binary and ternary model membrane mixtures and its coupling to membrane mechanics, is relatively well characterized. Elucidating the continuous turnover of live cell membranes, however, calls for experimental and theoretical membrane models enabling manipulation and investigation of directional mass transport. Here we introduce the phenomenon of curvature-induced domain nucleation and growth in membrane mixtures with fluid phase coexistence. Membrane domains were consistently observed to nucleate precisely at the junction between a strongly curved cylindrical (tube) membrane and a pipette-aspirated giant unilamellar vesicle. This experimental geometry mimics intracellular sorting compartments, because they often show tubular-vesicular membrane regions. Nucleated domains at tube necks were observed to present diffusion barriers to the transport of lipids and proteins. We find that curvature-nucleated domains grow with characteristic parabolic time dependence that is strongly curvature-dependent. We derive an analytical model that reflects the observed growth dynamics. Numerically calculated membrane shapes furthermore allow us to elucidate mechanical details underlying curvature-dependent directed lipid transport. Our observations suggest a novel dynamic membrane sorting principle that may contribute to intracellular protein and lipid sorting and trafficking. PMID:20368457

  16. Oxygen Transport Membranes

    S. Bandopadhyay

    2008-08-30

    small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume

  17. Population analysis of the cingulum bundle using the tubular surface model for schizophrenia detection

    Mohan, Vandana; Sundaramoorthi, Ganesh; Kubicki, Marek; Terry, Douglas; Tannenbaum, Allen

    2010-03-01

    We propose a novel framework for population analysis of DW-MRI data using the Tubular Surface Model. We focus on the Cingulum Bundle (CB) - a major tract for the Limbic System and the main connection of the Cingulate Gyrus, which has been associated with several aspects of Schizophrenia symptomatology. The Tubular Surface Model represents a tubular surface as a center-line with an associated radius function. It provides a natural way to sample statistics along the length of the fiber bundle and reduces the registration of fiber bundle surfaces to that of 4D curves. We apply our framework to a population of 20 subjects (10 normal, 10 schizophrenic) and obtain excellent results with neural network based classification (90% sensitivity, 95% specificity) as well as unsupervised clustering (k-means). Further, we apply statistical analysis to the feature data and characterize the discrimination ability of local regions of the CB, as a step towards localizing CB regions most relevant to Schizophrenia.

  18. Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption

    Leyssac, P P; Karlsen, F M; Holstein-Rathlou, N H

    1997-01-01

    The effect of physiological concentrations of angiotensin II on proximal tubular fluid reabsorption remains controversial. To investigate the effect of blockade of intratubular AT1 receptors on tubular reabsorption, losartan (10(-5) M) was administered by microperfusion into an early proximal...... flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load to the...... early and late proximal convolutions was estimated to be 7.8 nl/min (approximately 36%). It is concluded that a decrease in local luminal angiotensin II levels and/or AT1 receptor activity under free flow conditions increases the rate of proximal tubular fluid reabsorption....

  19. Ioxaglate-induced light and electron microscopic alterations in the renal proximal tubular epithelium of rats.

    Battenfeld, R; Khater A el-R; Drommer, W; Guenzel, P; Kaup, F J

    1991-01-01

    Vacuolization of the proximal tubular epithelial cells was produced in rats by the intravenous administration of the radiographic contrast medium ioxaglate at high multiples of the human diagnostic dose. Samples of the renal cortex and outer zone of the medulla were examined by light and electron microscopy. We observed enlargement, confluence, and migration of vacuoles containing pleomorphic dense material and distinct inclusion bodies. With time, vacuolization disappeared, though single vacuoles partly engaged in extruding their contents into the tubular lumen were still visible. We concluded that radiographic contrast medium at high dose levels can produce a reversible disturbance in the transport vesicular system of the proximal tubular epithelial cells without affecting the specific cell organelles. PMID:2022451

  20. Status report on the development of a tubular electron beam ion source

    The theoretical estimations and numerical simulations of tubular electron beams in both beam and reflex mode of source operation as well as the off-axis ion extraction from a tubular electron beam ion source (TEBIS) are presented. Numerical simulations have been done with the use of the IGUN and OPERA-3D codes. Numerical simulations with IGUN code show that the effective electron current can reach more than 100 A with a beam current density of about 300-400 A/cm2 and the electron energy in the region of several KeV with a corresponding increase of the ion output. Off-axis ion extraction from the TEBIS, being the nonaxially symmetric problem, was simulated with OPERA-3D (SCALA) code. The conceptual design and main parameters of new tubular sources which are under consideration at JINR, MSL, and BNL are based on these simulations

  1. Status report on the development of a tubular electron beam ion source

    Donets, E. D.; Donets, E. E.; Becker, R.; Liljeby, L.; Rensfelt, K.-G.; Beebe, E. N.; Pikin, A. I.

    2004-05-01

    The theoretical estimations and numerical simulations of tubular electron beams in both beam and reflex mode of source operation as well as the off-axis ion extraction from a tubular electron beam ion source (TEBIS) are presented. Numerical simulations have been done with the use of the IGUN and OPERA-3D codes. Numerical simulations with IGUN code show that the effective electron current can reach more than 100 A with a beam current density of about 300-400 A/cm2 and the electron energy in the region of several KeV with a corresponding increase of the ion output. Off-axis ion extraction from the TEBIS, being the nonaxially symmetric problem, was simulated with OPERA-3D (SCALA) code. The conceptual design and main parameters of new tubular sources which are under consideration at JINR, MSL, and BNL are based on these simulations.

  2. Inspection system for welded tubular joint based on ultrasonic phased array

    Hao Guangping; Deng Zongquan; Shan Baohua; Yu Weizhen; Li Lifang

    2010-01-01

    A manual inspection of large-diameter tubular joints is difficult. As a result a scanner with three degrees of freedom (DOFs) was developed based on the scanning principle of ultrasonic phased array. The weld tracing is realized by a 2D0F motion of scanner. The pose of ultrasonic probe is controlled by the third one. The control strategy is put forward based on a programmable multi-axis controller. Four kinds of scanning modes can be implemented simultaneously employing this ultrasonic inspection system. Experiments on reference blocks of tubular joints reveal that the automatic ultrasonic phased array inspection system has the same inspection accuracy as a manual ultrasonic inspection. This system is superior to the manual ultrasonic system in terms of reliability and repeatability. The artificial defects of weld at tubular joint can be detected accurately with the presented inspection system.

  3. Materials, geometry, and net energy ratio of tubular photo bioreactors for micro-algal hydrogen production

    We estimate the energy content, the operational energy inputs, and the net energy ratio (NER) of an industrial tubular photo bioreactor used for the photosynthetic production of H2 by micro-algae. The calculated H2 output of the photo bioreactor is based on a range of algal photosynthetic H2 generation efficiencies, and on the application of standard theory for tubular solar collectors. Small diameter reactors have a low NER as the mixing energy becomes large. For a tubular photo bioreactor, low density polyethylene (LDPE) film and glass have significantly higher NERs than rigid polymers such as poly-methyl methyl-acrylate (acrylic). Using a hypothetical improved micro-algal H2 generation efficiency of 5 %, a NER ∼ 6 can be obtained for LDPE film and for glass. For mechanical and assembly reasons LDPE film is the material of choice. These results show that photo bio-hydrogen could be a viable H2 generation technology. (authors)

  4. Energetics and electronic structure of tubular Si vacancies filled with carbon nanotubes

    Kochi, Taketo; Okada, Susumu

    2016-05-01

    We studied the energetics and electronic structure of tubular Si vacancies incorporating a carbon nanotube (CNT), using first-principles total-energy calculations based on the density functional theory. Our calculations show that the incorporated CNT into a Si nanotunnel acts as an atom-thickness liner providing the electrostatically flat nanoscale space inside them by shielding the dangling bond states of tubular Si vacancies. The incorporation of the CNT into the tubular Si vacancies is exothermic with an energy gain up to 7.4 eV/nm depending on the diameters of the vacancy and encapsulated CNT. The electronic states of the vacancy substantially hybridize with those of the CNT, leading to the complex electronic energy band near the Fermi level.

  5. Micro-Drilling of Polymer Tubular Ultramicroelectrode Arrays for Electrochemical Sensors

    Niels B. Larsen

    2013-05-01

    Full Text Available We present a reproducible fast prototyping procedure based on micro-drilling to produce homogeneous tubular ultramicroelectrode arrays made from poly(3,4-ethylenedioxythiophene (PEDOT, a conductive polymer. Arrays of Ø 100 µm tubular electrodes each having a height of 0.37 ± 0.06 µm were reproducibly fabricated. The electrode dimensions were analyzed by SEM after deposition of silver dendrites to visualize the electroactive electrode area. The electrochemical applicability of the electrodes was demonstrated by voltammetric and amperometric detection of ferri-/ferrocyanide. Recorded signals were in agreement with results from finite element modelling of the system. The tubular PEDOT ultramicroelectrode arrays were modified by prussian blue to enable the detection of hydrogen peroxide. A linear sensor response was demonstrated for hydrogen peroxide concentrations from 0.1 mM to 1 mM.

  6. Species diversity regarding the presence of proximal tubular progenitor cells of the kidney

    J. Hansson

    2016-02-01

    Full Text Available The cellular source for tubular regeneration following kidney injury is a matter of dispute, with reports suggesting a stem or progenitor cells as the regeneration source while linage tracing studies in mice seemingly favor the classical theory, where regeneration is performed by randomly surviving cells. We, and others have previously described a scattered cell population localized to the tubules of human kidney, which increases in number following injury. Here we have characterized the species distribution of these proximal tubular progenitor cells (PTPCs in kidney tissue from chimpanzee, pig, rat and mouse using a set of human PTPC markers. We detected PTPCs in chimpanzee and pig kidneys, but not in mouse tissue. Also, subjecting mice to the unilateral urethral obstruction model, caused clear signs of tubular injury, but failed to induce the PTPC phenotype in renal tubules.

  7. Interferon-γ Reduces the Proliferation of Primed Human Renal Tubular Cells

    Omar García-Sánchez

    2014-01-01

    Full Text Available Background/Aims: Chronic kidney disease (CKD is a progressive deterioration of the kidney function, which may eventually lead to renal failure and the need for dialysis or kidney transplant. Whether initiated in the glomeruli or the tubuli, CKD is characterized by progressive nephron loss, for which the process of tubular deletion is of key importance. Tubular deletion results from tubular epithelial cell death and defective repair, leading to scarring of the renal parenchyma. Several cytokines and signaling pathways, including transforming growth factor-β (TGF-β and the Fas pathway, have been shown to participate in vivo in tubular cell death. However, there is some controversy about their mode of action, since a direct effect on normal tubular cells has not been demonstrated. We hypothesized that epithelial cells would require specific priming to become sensitive to TGF-β or Fas stimulation and that this priming would be brought about by specific mediators found in the pathological scenario. Methods: Herein we studied whether the combined effect of several stimuli known to take part in CKD progression, namely TGF-β, tumor necrosis factor-α, interferon-γ (IFN-γ, and Fas stimulation, on primed resistant human tubular cells caused cell death or reduced proliferation. Results: We demonstrate that these cytokines have no synergistic effect on the proliferation or viability of human kidney (HK2 cells. We also demonstrate that IFN-γ, but not the other stimuli, reduces the proliferation of cycloheximide-primed HK2 cells without affecting their viability. Conclusion: Our results point at a potentially important role of IFN-γ in defective repair, leading to nephron loss during CKD.

  8. Ceria catalyst for inert-substrate-supported tubular solid oxide fuel cells running on methane fuel

    Zhao, Kai; Kim, Bok-Hee; Du, Yanhai; Xu, Qing; Ahn, Byung-Guk

    2016-05-01

    A ceria catalyst is applied to an inert-substrate supported tubular single cell for direct operation on methane fuel. The tubular single cell comprises a porous yttria-stabilized zirconia (YSZ) supporter, a Ni-Ce0.8Sm0.2O1.9 anode, a YSZ/Ce0.8Sm0.2O1.9 bi-layer electrolyte, and a La0.6Sr0.4Co0.2Fe0.8O3-δ cathode. The ceria catalyst is incorporated into the porous YSZ supporter layer by a cerium nitrate impregnation. The effects of ceria on the microstructure and electrochemical performance of the tubular single cell are investigated with respect to the number of impregnations. The optimum number of impregnations is determined to be four based on the maximum power density and polarization property of the tubular single cell in hydrogen and methane fuels. At 700 °C, the tubular single cell shows similar maximum power densities of ∼260 mW cm-2 in hydrogen and methane fuels, respectively. Moreover, the ceria catalyst significantly improves the performance stability of the cell running on methane fuel. At a current density of 350 mA cm-2, the single cell shows a low degradation rate of 2.5 mV h-1 during the 13 h test in methane fuel. These results suggest the feasibility of applying the ceria catalyst to the inert-substrate supported tubular single cell for direct operation on methane fuel.

  9. Renal tubular dysfunction with nephrocalcinosis in a patient with beta thalassemia minor

    Prabahar Murugesan

    2008-01-01

    Full Text Available Thalassemia is a hereditary anemia resulting from defect in hemoglobin production. Beta thalassemia is due to impaired production of beta globin chains, leading to a relative excess of alpha globin chains. The term beta thalassemia minor is used to describe heterozygotes, who carry one normal beta globin allele and one beta thalassemic allele. The vast majority of these patients are asymptomatic. However, a variety of renal tubular abnormalities including hypercalciuria, hypo-magnesemia with renal magnesium wasting, decreased tubular absorption of phosphorus, hypo-uricemia with renal uric acid wasting, renal glycosuria and tubular proteinuria have been described even in patients with beta thalassemia minor. We here in report a 24-year old female patient who was found to have thalassemia minor and nephrocalcinosis with evidence of renal tubular dysfunction. Investigations revealed normal renal function, hypercalciuria, reduced tubular reabsorption of phos-phorus, hypomagnesemia and renal magnesium wasting. Screening for aminoaciduria was found to be negative. An acid loading test revealed normal urinary acidification. Ultrasonogram of the abdomen revealed nephrocalcinosis and splenomegaly. Detailed work up for anemia showed normal white cell and platelet count while peripheral smear showed microcytic hypochromic anemia with few target cells. Hemoglobin electrophoresis revealed hemoglobin A of 92%, hemoglobin A2 of 6.2% and hemo-globin F of 1.8% consistent with beta thalassemia minor. Her parental screening was normal. A diag-nosis of beta thalassemia minor with renal tubular dysfunction was made and the patient was started on thiazide diuretics to reduce hypercalciuria and advised regular follow-up.

  10. Omniphobic Membrane for Robust Membrane Distillation

    Lin, SH; Nejati, S; Boo, C; Hu, YX; Osuji, CO; Ehmelech, M

    2014-11-01

    In this work, we fabricate an omniphobic microporous membrane for membrane distillation (MD) by modifying a hydrophilic glass fiber membrane with silica nanoparticles followed by surface fluorination and polymer coating. The modified glass fiber membrane exhibits an anti-wetting property not only against water but also against low surface tension organic solvents that easily wet a hydrophobic polytetrafluoroethylene (PTFE) membrane that is commonly used in MD applications. By comparing the performance of the PTFE and omniphobic membranes in direct contact MD experiments in the presence of a surfactant (sodium dodecyl sulfate, SDS), we show that SDS wets the hydrophobic PTFE membrane but not the omniphobic membrane. Our results suggest that omniphobic membranes are critical for MD applications with feed waters containing surface active species, such as oil and gas produced water, to prevent membrane pore wetting.

  11. Creep behaviour of candidate tubular ferritic oxide-dispersion-strengthened heat exchanger components

    Rees, M. [Commission of the European Communities, Petten (Netherlands). Joint Research Centre; Hurst, R.C.; Healy, J.C.; Parker, J.D. [University Coll. of Swansea (United Kingdom)

    1996-11-01

    The circumferential creep behaviour of two ferritic oxide dispersion stengthened (Fe-ODS) alloys, MA 956 and ODM 751, was studied by subjecting tubular components to constant internal pressure at 1100 {sup o}C. The grain aspect ratio and grain size governed the creep strength of these materials. The mechanisms of creep failure were investigated by optical microscopy and transmission electron microscopy. In spite of the inferior creep properties in the hoop direction compared to the longitudinal direction, these initial results indicate that, with proper control of the microstructure, tubular Fe-ODS alloys could be considered as candidate materials for heat exchanger components operating at elevated temperatures. (Author)

  12. Self-assembly of versatile tubular-like In2O3 nanostructures

    Versatile indium oxide tubular nanostructures (well-aligned nanotube arrays, flower-like tubular structures, and square nanotubes) were fabricated by a facile and reliable chemical vapor deposition (CVD) technique, taking advantage of the self-assembly property and substrate-induced epitaxial growth mechanism. The technique has a few advantages, such as low growth temperature, nonexistence of catalyst, template-free synthesis, direct bonding to the semiconductor substrates, etc. This strategy might extend the approach of synthesizing desirable nanostructures of other important low-melting metal oxides for potential applications

  13. Self-assembly of versatile tubular-like In(2)O(3) nanostructures.

    Zhong, Miao; Zheng, Maojun; Ma, Li; Li, Yanbo

    2007-11-21

    Versatile indium oxide tubular nanostructures (well-aligned nanotube arrays, flower-like tubular structures, and square nanotubes) were fabricated by a facile and reliable chemical vapor deposition (CVD) technique, taking advantage of the self-assembly property and substrate-induced epitaxial growth mechanism. The technique has a few advantages, such as low growth temperature, nonexistence of catalyst, template-free synthesis, direct bonding to the semiconductor substrates, etc. This strategy might extend the approach of synthesizing desirable nanostructures of other important low-melting metal oxides for potential applications. PMID:21730485

  14. Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

    Parvaiz Ahmad Koul

    2011-01-01

    Full Text Available A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery.

  15. Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism.

    Koul, Parvaiz Ahmad; Wahid, A

    2011-09-01

    A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery. PMID:21912036

  16. Facile Fabrication of Uniform Polyaniline Nanotubes with Tubular Aluminosilicates as Templates

    Zhang, Long; Liu, Peng

    2008-08-01

    The uniform polyaniline (PANI) nanotubes, with inner diameter, outer diameter, and tubular thickness of 40, 60, and 10 nm, respectively, were prepared successfully by using natural tubular aluminosilicates as templates. The halloysite nanotubes were coated with PANI via the in situ chemical oxidation polymerization. Then the templates were etched with HCl/HF solution. The PANI nanotubes were characterized using FTIR, X-ray diffraction, and transmission electron microscopy. The conductivity of the PANI nanotubes was found to be 1.752 × 10-5 (Ω·cm)-1.

  17. Mesenchymal stem cells modulate albumin-induced renal tubular inflammation and fibrosis.

    Hao Jia Wu

    Full Text Available Bone marrow-derived mesenchymal stem cells (BM-MSCs have recently shown promise as a therapeutic tool in various types of chronic kidney disease (CKD models. However, the mechanism of action is incompletely understood. As renal prognosis in CKD is largely determined by the degree of renal tubular injury that correlates with residual proteinuria, we hypothesized that BM-MSCs may exert modulatory effects on renal tubular inflammation and epithelial-to-mesenchymal transition (EMT under a protein-overloaded milieu. Using a co-culture model of human proximal tubular epithelial cells (PTECs and BM-MSCs, we showed that concomitant stimulation of BM-MSCs by albumin excess was a prerequisite for them to attenuate albumin-induced IL-6, IL-8, TNF-α, CCL-2, CCL-5 overexpression in PTECs, which was partly mediated via deactivation of tubular NF-κB signaling. In addition, albumin induced tubular EMT, as shown by E-cadherin loss and α-SMA, FN and collagen IV overexpression, was also prevented by BM-MSC co-culture. Albumin-overloaded BM-MSCs per se retained their tri-lineage differentiation capacity and overexpressed hepatocyte growth factor (HGF and TNFα-stimulating gene (TSG-6 via P38 and NF-κB signaling. Albumin-induced tubular CCL-2, CCL-5 and TNF-α overexpression were suppressed by recombinant HGF treatment, while the upregulation of α-SMA, FN and collagen IV was attenuated by recombinant TSG-6. Neutralizing HGF and TSG-6 abolished the anti-inflammatory and anti-EMT effects of BM-MSC co-culture in albumin-induced PTECs, respectively. In vivo, albumin-overloaded mice treated with mouse BM-MSCs had markedly reduced BUN, tubular CCL-2 and CCL-5 expression, α-SMA and collagen IV accumulation independent of changes in proteinuria. These data suggest anti-inflammatory and anti-fibrotic roles of BM-MSCs on renal tubular cells under a protein overloaded condition, probably mediated via the paracrine action of HGF and TSG-6.

  18. Non-linear finite element analysis of tubular X joint with selected geometry

    Ghanem Nia, Nima

    2012-01-01

    Tubular Joints” play a very important and quite vital role in most of the marine structures; we can see maybe hundreds of them in every even simple jacket or steel platforms. It is obvious that having full control about capacity and strength of tubular joints would be very worthy to have good knowledge about total performance of the structure. During recent years the application of the finite element (FE) method has become very popular in the analyses of different types of welded circular tu...

  19. Spray Deposition Behavior and Numerical Simulation of Growth of Tubular Preform in Spray Forming Process

    XIANG Jin-zong; ZHANG Yin; FAN Wen-jun; WANG Ping; HE You-duo

    2012-01-01

    Analysis on the deposition behavior of spray on deposition surface was made and an optimization method for the movement parameters (u, ω) of substrate was obtained. Simultaneously, a mathematical model of growth of tubular preform, specifically aimed at the kind of atomizer that is fixed and with a tilt angle was established. By in- tegrating the optimization method and the mathematical model, the growth process and shape of preform were simu- lated. The results show that the tilt angle of atomizer plays an important role on the dimensions and shapes of tubular preforms and it can provide a guidance for the development of spray forming equipment.

  20. Decolorization and partial mineralization of a polyazo dye by Bacillus firmus immobilized within tubular polymeric gel

    Ogugbue, Chimezie Jason; Morad, Norhashimah; Sawidis, Thomas; Oranusi, Nathaniel A.

    2011-01-01

    The degradation of C.I. Direct red 80, a polyazo dye, was investigated using Bacillus firmus immobilized by entrapment in tubular polymeric gel. This bacterial strain was able to completely decolorize 50 mg/L of C.I. Direct red 80 under anoxic conditions within 12 h and also degrade the reaction intermediates (aromatic amines) during the subsequent 12 h under aerobic conditions. The tubular gel harboring the immobilized cells consisted of anoxic and aerobic regions integrated in a single unit...

  1. Fabrication of Mesostructured Silica and Titania Rods on Substrates by Using Polycarbonate Membranes

    Norihiro Suzuki; Yusuke Yamauchi

    2010-01-01

    By using the polycarbonate membrane a template, mesoporous silica rods are fabricated on a silicon substrate in one pot. From scanning electron microscope (SEM) images, the creation of fibrous morphology is confirmed over the entire area. The diameter of the obtained rods is consistent with that of the template. Transmission electron microscope (TEM) images revealed that the tubular mesochannels are uniaxially oriented parallel to the longitudinal axis of the silica rods. The mesoporous titan...

  2. Characterization and performance of membranes designed for macroencapsulation/implantation of pancreatic islet cells.

    Isayeva, I S; Kasibhatla, B T; Rosenthal, K S; Kennedy, J P

    2003-09-01

    Amphiphilic polymer membranes were synthesized for macroencapsulation of cells and characterized by select chemical and biological techniques. The membranes were prepared by crosslinking hydrophilic poly(N,N-dimethyl acrylamide) (PDMAAm) main chains with hydrophobic di-, tri-, and octa-methacrylate telechelic polyisobutylene (PIB) stars. The hydrophilic/hydrophobic composition and the molecular weights between crosslink sites (both M(c,hydrophilic) and M(c,hydrophobic)) were controlled by synthesis conditions. Small tubular membranes were made by in situ rotational copolymerization/crosslinking and filled with pancreatic rat islets. The water-swelling behavior, mechanical properties, and oxygen and insulin diffusion were studied. Macroencapsulatory performance of these membranes was investigated in vitro by macroencapsulation of pancreatic rat islets within tubular membranes for up to 1.5 months, and studying the insulin secreting ability of encapsulated islets in culture. The membranes are robust and maintain their integrity for the period of encapsulation. They allow oxygen and insulin diffusion. Macroencapsulated islets maintained their viability and insulin secretion over an extended period (i.e., 45 days). PMID:12809777

  3. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    Highlights: •We have attempted in vivo nephron generation using conditioned media. •Vascular and tubular cells do cross-talks on cell proliferation and tubular changes. •Tubular cells suppress these changes in mesenchymal stem cells. •Tubular cells differentiate mesenchymal stem cells into tubular cells. •Nephrons can be created from implanted tubular cells or mesenchymal stem cells. -- Abstract: There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues

  4. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    Machiguchi, Toshihiko, E-mail: machiguchi.toshihiko.23u@st.kyoto-u.ac.jp; Nakamura, Tatsuo, E-mail: nakamura@frontier.kyoto-u.ac.jp

    2013-06-07

    Highlights: •We have attempted in vivo nephron generation using conditioned media. •Vascular and tubular cells do cross-talks on cell proliferation and tubular changes. •Tubular cells suppress these changes in mesenchymal stem cells. •Tubular cells differentiate mesenchymal stem cells into tubular cells. •Nephrons can be created from implanted tubular cells or mesenchymal stem cells. -- Abstract: There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues.

  5. Inositol 1,4,5-trisphosphate-induced calcium release from platelet plasma membrane vesicles

    A platelet membrane preparation, enriched in plasma membrane markers, took up 45Ca2+ in exchange for intravesicular Na+ and released it after the addition of inositol 1,4,5-trisphosphate (IP3). The possibility that contaminating dense tubular membrane (DTS) vesicles contributed the Ca2+ released by IP3 was eliminated by the addition of vanadate to inhibit Ca+-ATPase-mediated DTS Ca2+ sequestration and by the finding that only plasma membrane vesicles exhibit Na+-dependent Ca2+ uptake. Ca2+ released by IP3 was dependent on low extravesicular Ca2+ concentrations. IP3-induced Ca2+ release was additive to that released by Na+ addition while GTP or polyethylene glycol (PEG) had no effect. These results strongly suggest that IP3 facilitates extracellular Ca2+ influx in addition to release from DTS membranes

  6. Insulin's acute effects on glomerular filtration rate correlate with insulin sensitivity whereas insulin's acute effects on proximal tubular sodium reabsorption correlate with salt sensitivity in normal subjects

    ter Maaten, JC; Bakker, SJL; Serne, EH; ter Wee, PM; Gans, ROB

    1999-01-01

    Background. Insulin induces increasing distal tubular sodium reabsorption. Opposite effects of insulin to offset insulin-induced sodium retention are supposedly increases in glomerular filtration rate (GFR) and decreases in proximal tubular sodium reabsorption. Defects in these opposing effects coul

  7. Horizontally rotated cell culture system with a coaxial tubular oxygenator

    Wolf, David A. (Inventor); Schwarz, Ray P. (Inventor); Trinh, Tinh T. (Inventor)

    1991-01-01

    The present invention relates to a horizontally rotating bioreactor useful for carrying out cell and tissue culture. For processing of mammalian cells, the system is sterilized and fresh fluid medium, microcarrier beads, and cells are admitted to completely fill the cell culture vessel. An oxygen containing gas is admitted to the interior of the permeable membrane which prevents air bubbles from being introduced into the medium. The cylinder is rotated at a low speed within an incubator so that the circular motion of the fluid medium uniformly suspends the microbeads throughout the cylinder during the cell growth period. The unique design of this cell and tissue culture device was initially driven by two requirements imposed by its intended use for feasibility studies for three dimensional culture of living cells and tissues in space by JSC. They were compatible with microgravity and simulation of microgravity in one G. The vessels are designed to approximate the extremely quiescent low shear environment obtainable in space.

  8. Strain and stress variations in the human amniotic membrane and fresh corpse autologous sciatic nerve anastomosis in a model of sciatic nerve injury☆

    Peng, Chuangang; Zhang, Qiao; Yang, Qi; Zhu, QingSan

    2012-01-01

    A 10-mm long sciatic nerve injury model was established in fresh normal Chinese patient cadavers. Amniotic membrane was harvested from healthy maternal placentas and was prepared into multilayered, coiled, tubular specimens. Sciatic nerve injury models were respectively anastomosed using the autologous cadaveric sciatic nerve and human amniotic membrane. Tensile test results showed that maximal loading, maximal displacement, maximal stress, and maximal strain of sciatic nerve injury models an...

  9. AAO Starbugs: software control and associated algorithms

    Lorente, Nuria P F; Shortridge, Keith; Farrell, Tony J; Smedley, Scott; Hong, Sungwook E; Bacigalupo, Carlos; Goodwin, Michael; Kuehn, Kyler; Satorre, Christophe

    2016-01-01

    The Australian Astronomical Observatory's TAIPAN instrument deploys 150 Starbug robots to position optical fibres to accuracies of 0.3 arcsec, on a 32 cm glass field plate on the focal plane of the 1.2 m UK-Schmidt telescope. This paper describes the software system developed to control and monitor the Starbugs, with particular emphasis on the automated path-finding algorithms, and the metrology software which keeps track of the position and motion of individual Starbugs as they independently move in a crowded field. The software employs a tiered approach to find a collision-free path for every Starbug, from its current position to its target location. This consists of three path-finding stages of increasing complexity and computational cost. For each Starbug a path is attempted using a simple method. If unsuccessful, subsequently more complex (and expensive) methods are tried until a valid path is found or the target is flagged as unreachable.

  10. Membranes for energy conversion

    Peinemann, K.V.; Pereira Nunes, S. (eds.) [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    2008-07-01

    This volume contains the following chapters: 1. Sulfonated poly(arylether)-type polymers as proton exchange membranes: Synthesis and performance; 2. Polyimide ionomer membranes for PEFCs and DMFCs; 3. Membranes for high temperature PEFC based on acid-doped polybenzimidazoles; 4. Membrane for medium temperature PEFC based on Nafion filled with layered metal phosphates and phosphonates 5. Composite membranes for high temperature direct methanol fuel cells; 6. Dense ceramic membranes for hydrogen separation; 7. Membranes in energy systems with CO{sub 2} capture 8. Palladium membranes for hydrogen separation; 9. Membranes for power generation by pressure retarded osmosis.

  11. Electrophysiology of mycoplasma membranes.

    Schummer, U.; Schiefer, H G

    1983-01-01

    The influence of transmembrane ion fluxes on mycoplasma membrane potentials was studied. Fluorescence intensity of potential-sensitive carbocyanine dyes was calibrated vs. electric membrane potential. Potassium and sodium ion diffusion potentials significantly contributed to mycoplasma membrane potential. Chloride ions were obviously freely permeable across mycoplasma membranes. Under growth conditions the mycoplasma membrane potential was estimated to be delta psi = - 80 mV.

  12. Gremlin Activates the Smad Pathway Linked to Epithelial Mesenchymal Transdifferentiation in Cultured Tubular Epithelial Cells

    Raquel Rodrigues-Diez

    2014-01-01

    Full Text Available Gremlin is a developmental gene upregulated in human chronic kidney disease and in renal cells in response to transforming growth factor-β (TGF-β. Epithelial mesenchymal transition (EMT is one process involved in renal fibrosis. In tubular epithelial cells we have recently described that Gremlin induces EMT and acts as a downstream TGF-β mediator. Our aim was to investigate whether Gremlin participates in EMT by the regulation of the Smad pathway. Stimulation of human tubular epithelial cells (HK2 with Gremlin caused an early activation of the Smad signaling pathway (Smad 2/3 phosphorylation, nuclear translocation, and Smad-dependent gene transcription. The blockade of TGF-β, by a neutralizing antibody against active TGF-β, did not modify Gremlin-induced early Smad activation. These data show that Gremlin directly, by a TGF-β independent process, activates the Smad pathway. In tubular epithelial cells long-term incubation with Gremlin increased TGF-β production and caused a sustained Smad activation and a phenotype conversion into myofibroblasts-like cells. Smad 7 overexpression, which blocks Smad 2/3 activation, diminished EMT changes observed in Gremlin-transfected tubuloepithelial cells. TGF-β neutralization also diminished Gremlin-induced EMT changes. In conclusion, we propose that Gremlin could participate in renal fibrosis by inducing EMT in tubular epithelial cells through activation of Smad pathway and induction of TGF-β.

  13. Generation of tubular beams of negative hydrogen ions by a surface plasma source

    The results of experiments on obtaining a tubular beam of hydrogen negative ions from a surface plasma source with emission ring slit of 100 mm diameter are described in the study. Conditions of burning of a high current ring discharge generating effectively hydrogen negative ions with current density up to 2.1 A/cm2 are investigated. The possibility of generation of intensive tubular beams of hydrogen negative ions by surface plasma sources is shown, the 2.4 A ion beam is obtained. The results of preliminary experiments on accelerating tubular beam up to 135 keV are described. Azymuthally uniform current density distribution of intensive tubular beams generated by discharges with a close electron drift in a surface plasma source with emission ring slit, absence of high-frequency oscillations in optimal conditions of sources operation as well as the possibility of the most complete use of generated by the discharge negative ions flow show the prospects of development of these sources for fast atom injectors

  14. Preparation of Ethylene Glycol Monoethyl Ether Acetate Using a Tubular Reactor

    蔡振云; 卢祖国; 李小波

    2003-01-01

    Ethylene glycol monoethyl ether acetate (EGEA), an excellent solvent, is prepared with ethylene oxide (EO) and ethyl acetate (EA) in a tubular reactor under suitable reaction condition. The single circulation yield can reach 81%. This technology is not only safe but also makes it possible to continuously produce EGEA in industry,with low content of high boiling point by-products.

  15. A quantitative model of the cardiac ventricular cell incorporating the transverse-axial tubular system

    Pásek, Michal; Christé, G.; Šimurda, J.

    2003-01-01

    Roč. 22, č. 3 (2003), s. 355-368. ISSN 0231-5882 R&D Projects: GA ČR GP204/02/D129 Institutional research plan: CEZ:AV0Z2076919 Keywords : cardiac cell * tubular system * quantitative modelling Subject RIV: BO - Biophysics Impact factor: 0.794, year: 2003

  16. Tubular Detector of Silver Solid Amalgam for Electrochemical Measurements in Flow Systems

    Yosypchuk, O.; Barek, J.; Josypčuk, Bohdan

    2012-01-01

    Roč. 24, č. 12 (2012), s. 2230-2234. ISSN 1040-0397 R&D Projects: GA ČR GAP206/11/1638 Institutional support: RVO:61388955 Keywords : flow injection analysis * tubular detector * silver solid amalgam Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.817, year: 2012

  17. Type IV renal tubular acidosis and spironolactone therapy in the elderly.

    O'Connell, J. E.; Colledge, N. R.

    1993-01-01

    Spironolactone therapy is a well-known cause of hyperkalaemia, but in susceptible patient, it may also be associated with metabolic acidosis. We report a case of severe renal tubular acidosis (Type IV) with life-threatening hyperkalaemia caused by spironolactone, and discuss the mechanisms by which this may occur.

  18. Classification of capped tubular viral particles in the family of Papovaviridae

    Keef, T.; Taormina, A.; Twarock, R.

    2006-04-01

    A vital constituent of a virus is its protein shell, called the viral capsid, that encapsulates and hence provides protection for the viral genome. Viral capsids are usually spherical, and for a significant number of viruses they exhibit overall icosahedral symmetry. The corresponding surface lattices, that encode the locations of the capsid proteins and intersubunit bonds, can be modelled by viral tiling theory. It has been shown in vitro that under a variation of the experimental boundary conditions, such as the pH value and salt concentration, tubular particles may appear instead of, or in addition to, spherical ones. In order to develop models that describe the simultaneous assembly of both spherical and tubular variants, and hence study the possibility of triggering tubular malformations as a means of interference with the replication mechanism, viral tiling theory has to be extended to include tubular lattices with end caps. We focus here on the case of Papovaviridae, which play a distinguished role from the viral structural point of view as they correspond to all pentamer lattices, i.e. lattices formed from clusters of five protein subunits throughout. These results pave the way for a generalization of recently developed assembly models.

  19. Classification of capped tubular viral particles in the family of Papovaviridae

    Keef, T [Department of Mathematics, University of York, York YO10 5DD (United Kingdom); Taormina, A [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom); Twarock, R [Department of Mathematics, University of York, York YO10 5DD (United Kingdom); Carlos [Istituto di Chimica del Riconoscimento Molecolare, CNR, Via Mario Bianco 9, 20131 Milan (Italy); Department of Biology, University of York, York YO10 5DD (United Kingdom)

    2006-04-12

    A vital constituent of a virus is its protein shell, called the viral capsid, that encapsulates and hence provides protection for the viral genome. Viral capsids are usually spherical, and for a significant number of viruses they exhibit overall icosahedral symmetry. The corresponding surface lattices, that encode the locations of the capsid proteins and intersubunit bonds, can be modelled by viral tiling theory. It has been shown in vitro that under a variation of the experimental boundary conditions, such as the pH value and salt concentration, tubular particles may appear instead of, or in addition to, spherical ones. In order to develop models that describe the simultaneous assembly of both spherical and tubular variants, and hence study the possibility of triggering tubular malformations as a means of interference with the replication mechanism, viral tiling theory has to be extended to include tubular lattices with end caps. We focus here on the case of Papovaviridae, which play a distinguished role from the viral structural point of view as they correspond to all pentamer lattices, i.e. lattices formed from clusters of five protein subunits throughout. These results pave the way for a generalization of recently developed assembly models.

  20. Hypokalemic quadriparesis and rhabdomyolysis as a rare presentation of distal renal tubular acidosis

    Ahmad Bhat, Manzoor; Ahmad Laway, Bashir; Mustafa, Farhat; Shafi Kuchay, Mohammad; Mubarik, Idrees; Ahmad Palla, Nazir

    2014-01-01

    Distal renal tubular acidosis is a syndrome of abnormal urine acidification and is characterized by hyperchloremic metabolic acidosis, hypokalemia, hypercalciurea, nephrocalcinosis and nephrolithiasis. Despite the presence of persistent hypokalemia, acute muscular paralysis is rarely encountered in males. Here, we will report an eighteen year old male patient who presented with flaccid quadriparesis and was subsequently found to have rhabdomyolysis, severe short stature, skeletal deformities ...

  1. Internal ballistics of recoilless high-low pressure guns using hepta-tubular powders

    M. C. Gupta

    1960-04-01

    Full Text Available In this paper, the theory of recoilless high-low pressure guns has been discussed by taking the form function and the results have been applied to the case of hepta-tubular powders. The results for high-low pressure guns follow as a particular case.

  2. The effect of RAAS blockade on markers of renal tubular damage in diabetic nephropathy

    Nielsen, Stine; Rossing, Kasper; Hess, Georg;

    2012-01-01

    Blockade of the renin-angiotensin-aldosterone system (RAAS) affects both the glomerulus and tubules. We aimed to investigate the effect of irbesartan on the tubular markers: urinary (u) neutrophil gelatinase associated protein (NGAL), Kidney injury molecule 1 (KIM1) and liver-fatty acid......-binding protein (LFABP)....

  3. Tubular engraftment and myofibroblast differentiation of recipient-derived cells after experimental kidney transplantation

    Broekema, Martine; Harmsen, Martin C.; Koerts, Jasper A.; Van Kooten, Theo G.; Navis, Gerjan; Van Luyn, Marja J. A.; Popa, Eliane R.

    2007-01-01

    Background. In human renal allografts, recipient-derived cells engrafted in various kidney substructures, have been detected in the long term after transplantation. Here we investigated tubular engraftment and myofibroblast differentiation of recipient-derived cells at short term after experimental

  4. 78 FR 56865 - Certain Oil Country Tubular Goods From India and Turkey: Postponement of Preliminary...

    2013-09-16

    ..., income tax incentives, and the provision of goods and services for less than adequate remuneration. Due... Investigations, 78 FR 45502 (July 29, 2013). Postponement of Due Date for the Preliminary Determination Section... International Trade Administration Certain Oil Country Tubular Goods From India and Turkey: Postponement...

  5. Stenosis map for volume visualization of constricted tubular structures: Application to coronary artery stenosis.

    Yun, Jihye; Kim, Yeo Koon; Chun, Eun Ju; Shin, Yeong-Gil; Lee, Jeongjin; Kim, Bohyoung

    2016-02-01

    Although direct volume rendering (DVR) has become a commodity, effective rendering of interesting features is still a challenge. In one of active DVR application fields, the medicine, radiologists have used DVR for the diagnosis of lesions or diseases that should be visualized distinguishably from other surrounding anatomical structures. One of most frequent and important radiologic tasks is the detection of lesions, usually constrictions, in complex tubular structures. In this paper, we propose a 3D spatial field for the effective visualization of constricted tubular structures, called as a stenosis map which stores the degree of constriction at each voxel. Constrictions within tubular structures are quantified by using newly proposed measures (i.e. line similarity measure and constriction measure) based on the localized structure analysis, and classified with a proposed transfer function mapping the degree of constriction to color and opacity. We show the application results of our method to the visualization of coronary artery stenoses. We present performance evaluations using twenty eight clinical datasets, demonstrating high accuracy and efficacy of our proposed method. The ability of our method to saliently visualize the constrictions within tubular structures and interactively adjust the visual appearance of the constrictions proves to deliver a substantial aid in radiologic practice. PMID:26608866

  6. Study on the assessment of renal tubular function with combined determination of multiple markers

    Objective: To investigate the degree of tubular injury in patients with glomerular diseases by measuring the urinary contents of various tubular function markers (THP, RBP, α1-m, β2-m, NAG, ET-1 ) and IL-6 as well as free water clearance. Methods: Twenty four hour urinary contents of THP, α1-m, β2-m, ET-1, IL-6 (with RIA) RBP (with ELISA) and NAG (with colorimetry) as well as free water clearance were determined in 353 patients with various kinds of primary glomerular diseases and 32 controls. Results: Renal tubular injury was most pronounced in patients with chronic renal failure followed by patients with lupus nephritis. In patients with chronic renal failure (n=36 ), urinary contents of all these markers were significantly different from those in controls (P<0.01). In other patients, urinary contents of at least one or several markers were significantly different from those in controls with the exception of patients with latent nephritis (n=8). Conclusion: Renal tubular function damage could be demonstrated in most of the patients with primary glomerular diseases. (authors)

  7. Tubular and Glomerular Injury in Diabetes and the Impact of ACE Inhibition

    Nielsen, Stine E.; Sugaya, Takeshi; Tarnow, Lise; Lajer, Maria; Schjoedt, Katrine J.; Astrup, Anne Sofie; Baba, Tsuneharu; Parving, Hans-Henrik; Rossing, Peter

    2009-01-01

    OBJECTIVE We studied tubular and glomerular damage in type 1 diabetic patients by measuring urinary–liver fatty acid binding protein (U-LFABP) and albuminuria. Subsequently, we evaluated the effect of ACE inhibition on U-LFABP in patients with diabetic nephropathy. RESEARCH DESIGN AND METHODS We studied Caucasians with type 1 diabetes: 58 with normoalbuminuria (urinary albumin

  8. 78 FR 77420 - Certain Oil Country Tubular Goods From the Republic of Turkey: Preliminary Negative...

    2013-12-23

    ... Duty Investigations, 78 FR 45505 (July 29, 2013). \\2\\ Maverick Tube Corporation, United States Steel Corporation, Boomerang Tube, Energex Tube, a division of JMC Steel Group, Northwest Pipe Company, Tejas Tubular Products, TMK IPSCO, Vallourec Star, L.P., and Welded Tube USA Inc. Scope of the Investigation...

  9. Porous layer open tubular columns with immobilized trypsin for protein digestion

    Knob, R.

    2013-01-01

    We have developed a monolithic porous layer open tubular (PLOT) column with immobilized trypsin for protein digestion. The PLOT column was prepared in a 10 (mikro)m ID fused silica capillary. Trypsin was immobilized on the monolithic surface and the developed enzyme reactor was used for protein digestion followed by on-line ESI/MS analysis.

  10. In-line quantification and characterization of membrane fouling

    Bucs, Szilard

    2016-06-16

    Methods of detecting, quantifying and/or characterizing the fouling of a device from a combination of pressure and spectroscopic data are provided. The device can be any device containing components susceptible to fouling. Components can include membranes, pipes, or reactors. Suitable devices include membrane devices, heat exchangers, and chemical or bio-reactors. Membrane devices can include, for example, microfiltration devices, ultrafiltration devices, nanofiltration devices, reverse osmosis, forward osmosis, osmosis, reverse electrodialysis, electro- deionisation or membrane distillation devices. The methods can be applied to any type of membrane, including tubular, spiral, hollow fiber, flat sheet, and capillary membranes. The spectroscopic characterization can include measuring one or more of the absorption, fluorescence, or raman spectroscopic data of one or more foulants. The methods can allow for the early detection and/or characterization of fouling. The characterization can include determining the specific foulant(s) or type of foulant(s) present. The characterization of fouling can allow for the selection of an appropriate de-fouling method and timing.

  11. Characterization of angiotensin-converting enzyme 2 ectodomain shedding from mouse proximal tubular cells.

    Fengxia Xiao

    Full Text Available Angiotensin-converting enzyme 2 (ACE2 is highly expressed in the kidney proximal tubule, where it cleaves angiotensin (Ang II to Ang-(1-7. Urinary ACE2 levels increase in diabetes, suggesting that ACE2 may be shed from tubular cells. The aim of this study was to determine if ACE2 is shed from proximal tubular cells, to characterize ACE2 fragments, and to study pathways for shedding. Studies involved primary cultures of mouse proximal tubular cells, with ACE2 activity measured using a synthetic substrate, and analysis of ACE2 fragments by immunoblots and mass spectrometry. The culture media from mouse proximal tubular cells demonstrated a time-dependent increase in ACE2 activity, suggesting constitutive ACE2 shedding. ACE2 was detected in media as two bands at ∼ 90 kDa and ∼ 70 kDa on immunoblots. By contrast, full-length ACE2 appeared at ∼ 100 kDa in cell lysates or mouse kidney cortex. Mass spectrometry of the two deglycosylated fragments identified peptides matching mouse ACE2 at positions 18-706 and 18-577, respectively. The C-terminus of the 18-706 peptide fragment contained a non-tryptic site, suggesting that Met(706 is a candidate ACE2 cleavage site. Incubation of cells in high D-glucose (25 mM (and to a lesser extent Ang II for 48-72 h increased ACE2 activity in the media (p<0.001, an effect blocked by inhibition of a disintegrin and metalloproteinase (ADAM17. High D-glucose increased ADAM17 activity in cell lysates (p<0.05. These data indicate that two glycosylated ACE2 fragments are constitutively shed from mouse proximal tubular cells. ACE2 shedding is stimulated by high D-glucose, at least partly via an ADAM17-mediated pathway. The results suggest that proximal tubular shedding of ACE2 may increase in diabetes, which could enhance degradation of Ang II in the tubular lumen, and increase levels of Ang-(1-7.

  12. From biological membranes to biomimetic model membranes

    Eeman, M.

    2010-01-01

    Full Text Available Biological membranes play an essential role in the cellular protection as well as in the control and the transport of nutrients. Many mechanisms such as molecular recognition, enzymatic catalysis, cellular adhesion and membrane fusion take place into the biological membranes. In 1972, Singer et al. provided a membrane model, called fluid mosaic model, in which each leaflet of the bilayer is formed by a homogeneous environment of lipids in a fluid state including globular assembling of proteins and glycoproteins. Since its conception in 1972, many developments were brought to this model in terms of composition and molecular organization. The main development of the fluid mosaic model was made by Simons et al. (1997 and Brown et al. (1997 who suggested that membrane lipids are organized into lateral microdomains (or lipid rafts with a specific composition and a molecular dynamic that are different to the composition and the dynamic of the surrounding liquid crystalline phase. The discovery of a phase separation in the plane of the membrane has induced an explosion in the research efforts related to the biology of cell membranes but also in the development of new technologies for the study of these biological systems. Due to the high complexity of biological membranes and in order to investigate the biological processes that occur on the membrane surface or within the membrane lipid bilayer, a large number of studies are performed using biomimicking model membranes. This paper aims at revisiting the fundamental properties of biological membranes in terms of membrane composition, membrane dynamic and molecular organization, as well as at describing the most common biomimicking models that are frequently used for investigating biological processes such as membrane fusion, membrane trafficking, pore formation as well as membrane interactions at a molecular level.

  13. Elliptical modelling of hysteresis operating characteristics in a dielectric elastomer tubular actuator

    Tian, Pengfei; Jones, Richard W.; Yu, Fei

    2016-07-01

    A dielectric elastomer (DE) tubular actuator, based on compliant metal electrode technology, exhibits hysteresis-like characteristics when driven with a low power rated high voltage power supply (HVPS). This behavior occurs mainly because the DE actuator acts as a capacitive load compromising the ‘slew rate’ of the HVPS during the actuator’s operation. The motivation of this contribution is to investigate the use of elliptical modelling approaches for capturing the hysteresis characteristics exhibited by the DE tubular actuator when it is driven by a low cost low power rated HVPS. The DE tubular actuator considered in this work demonstrates asymmetric hysteresis behaviour due to the nonlinear voltage–strain behaviour of the actuator. A linearization filter placed in series with the actuator (during its operation) ensures a symmetric hysteresis characteristic that can then be modelled using an ellipse-based approach. Elliptical models come in many forms with the two most popular being the constrained general conic form and the general parametric form. Elliptical-based hysteresis model fits are carried out on experimental data obtained from the application of periodic input voltages, at a number of different low-frequencies, to the tubular actuator. The range of frequencies used is related to the possible use of the tubular actuator for attenuating low frequency vibration during DE actuator-based load positioning applications. Constrained conic and general parametric forms of elliptical model are used for modelling the hysteresis characteristics of the DE actuator and rate dependent models developed based on both approaches. The sensitivity of both of these rate dependent models to small inaccuracies in model parameters was then investigated. The general parametric form was found to be more robust in this respect.

  14. Renal tubular epithelial cell prorenin receptor regulates blood pressure and sodium transport.

    Ramkumar, Nirupama; Stuart, Deborah; Mironova, Elena; Bugay, Vladislav; Wang, Shuping; Abraham, Nikita; Ichihara, Atsuhiro; Stockand, James D; Kohan, Donald E

    2016-07-01

    The physiological significance of the renal tubular prorenin receptor (PRR) has been difficult to elucidate due to developmental abnormalities associated with global or renal-specific PRR knockout (KO). We recently developed an inducible renal tubule-wide PRR KO using the Pax8/LC1 transgenes and demonstrated that disruption of renal tubular PRR at 1 mo of age caused no renal histological abnormalities. Here, we examined the role of renal tubular PRR in blood pressure (BP) regulation and Na(+) excretion and investigated the signaling mechanisms by which PRR regulates Na(+) balance. No detectable differences in BP were observed between control and PRR KO mice fed normal- or low-Na(+) diets. However, compared with controls, PRR KO mice had elevated plasma renin concentration and lower cumulative Na(+) balance with normal- and low-Na(+) intake. PRR KO mice had an attenuated hypertensive response and reduced Na(+) retention following angiotensin II (ANG II) infusion. Furthermore, PRR KO mice had significantly lower epithelial Na(+) channel (ENaC-α) expression. Treatment with mouse prorenin increased, while PRR antagonism decreased, ENaC activity in isolated split-open collecting ducts (CD). The prorenin effect was prevented by protein kinase A and Akt inhibition, but unaffected by blockade of AT1, ERK1/2, or p38 MAPK pathways. Taken together, these data indicate that renal tubular PRR, likely via direct prorenin/renin stimulation of PKA/Akt-dependent pathways, stimulates CD ENaC activity. Absence of renal tubular PRR promotes Na(+) wasting and reduces the hypertensive response to ANG II. PMID:27053687

  15. Radiation-induced changes in the kinetics of glomerular and tubular cells in the pig kidney

    Both kidneys of 13 mature female Large White pigs were irradiated with a single dose of 9.8 Gy 60Co γ rays. The pigs were killed serially between 2 to 24 weeks after irradiation. One hour prior to sacrifice bromodeoxyuridine (BrdU) (500 mg/pig) was injected intravenously. At postmortem the kidneys were removed and tissue was taken to prepare cell suspensions. The labeling index (LI) of these suspensions was determined using flow cytometry. In vivo BrdU incorporation in tubular and glomerular cells was determined immunohistochemically. The kinetics of glomerular and tubular cells was evaluated by counting the number of labeled cells/glomerules and the number of labeled tubular cells/fields of view. An average of 1200 glomeruli and 1500 fields of view/time were counted. Similar analyses were performed on renal tissue from unirradiated control animals. Flow cytometry revealed rapid and significant increases in the LI of kidney cells; 2 weeks after irradiation the LI increased from a control value of 0.18 ± 0.01 to 1.23 ± 0.22% (P < 0.001). By 4 weeks the maximal value of 2.45 ± 0.36% was seen; the LI then declined progressively but at 24 weeks after irradiation still remained significantly above control values (P < 0.001). A similar pattern of response was determined by counting the laveled glomerular and tubular cells identified immunohistochemically. However, the increase in labeled glomerular cells occurred 2 weeks after irradiation, whereas that for the tubules occurred 4 weeks after irradiation. These findings indicate that irradiation of the kidney, classically regarded as a open-quotes late-respondingclose quotes organ, is associated with rapid and significant changes in the kinetics of both tubular and glomerular cells. 28 refs., 4 figs

  16. Glomerular filtration and tubular secretion of MAG-3 in the rat kidney

    Technetium-99m mercaptoacetyltriglycine (MAG-3) has recently been introduced as a new radiopharmaceutical for dynamic renal scintigraphy. To elucidate the mechanism of renal excretion, micropuncture experiments were performed in rat kidneys for direct measurements of glomerular filtration and tubular secretory capacity. Fluid of Bowman space was collected from superficial glomeruli and analyzed for its contents of [99mTc]MAG-3, [125I]hippurate and [3H]inulin during constant infusion of these compounds. The ratio of activity of ultrafiltrate to that of arterial plasma was 0.23 for MAG-3, 0.68 for hippurate and 1.04 for inulin which demonstrates that the filtrated amount of MAG-3 is only 23% of that of inulin, presumably because of higher plasma protein binding which was also measured in vitro and found to be 80 +/- 1.5% for MAG-3 and 32 +/- 2% for [125I]hippurate. Proximal and distal tubules were also micropunctured and their tubular fluid as well as the final urine analyzed for the activity of hippurate and MAG-3. The tubular fluid to plasma ratio values along the nephron and in the final urine were all lower for MAG-3 than for hippurate, indicating a lower secretory capacity. From measurements of whole renal clearance, GFR and plasma protein binding the filtered amount of MAG-3 was 0.26 and of hippurate 0.87 ml/min.g kidney weight (p less than 0.001) and the secreted amount 2.01 and 2.38 ml/min.g kidney weight (p less than 0.05), respectively. We conclude that MAG-3 is predominantly excreted by tubular secretion and that the lower renal clearance of MAG-3 as compared with that of hippurate is a result both of a substantially decreased glomerular filtration and of a lower tubular secretion

  17. RHODOPSIN-LIPID INTERACTIONS STUDIED BY NMR

    Soubias, Olivier; Gawrisch, Klaus

    2013-01-01

    The biophysical properties of the lipid matrix are known to influence function of integral membrane proteins. We report on a sample preparation method for reconstitution of membrane proteins which uses porous anodic aluminum oxide (AAO) filters with 200 nm-wide pores of high density. The substrate permits formation of tubular, single membranes that line the inner surface of pores. One square centimeter of filter with a thickness of 60 μm yields on the order of 500 cm2 of solid-supported singl...

  18. Anaerobic membrane bioreactors: Are membranes really necessary?

    Davila, M.; Kassab, G.; Klapwijk, A.; Van, Lier, G

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A self-forming dynamic membrane only requires a support material over which a cake layer is formed, which determines the rejection properties of the system. The present research studies the applicat...

  19. Anaerobic membrane bioreactors: Are membranes really necessary?

    Davila, M.; Kassab, G.; Klapwijk, A.; Lier, van J.B.

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A

  20. Design of Pd-based membrane reactor for gas detritiation

    The development of a Pd-based membrane reactor to be applied in processes for tritium removal from various gaseous streams of tokamak systems has been carried out. In particular, the membrane reactor has been designed for decontaminating soft housekeeping wastes of JET. This membrane reactor consists of Pd-Ag permeator tube fixed in a finger-like mode into a stainless steel shell. The feed stream (gases to be detritiated) is fed inside the membrane lumen where the isotopic exchange takes place on to a catalyst bed while pure hydrogen (protium) is sent in countercurrent mode in the shell side. The feed stream consists of 200 Ncm3 min-1 of helium with 10% of tritiated water (tritium content 1.11 x 108 Bq h-1). The membrane reactor design has been based on a simplified calculation model which takes into consideration the very low tritium content of the gas to be processed and the complete oxidation of the tritiated species in the feed stream. The model considers a tubular Pd-Ag membrane divided into finite elements where the mass balances are performed according to both the thermodynamic equilibrium reactions and permeation rates through the membrane of the hydrogen isotopes. The reactor model has permitted to verify that a Pd-Ag commercial tube of diameter 10 mm, length 500 mm and wall thickness 0.150 mm is capable to attain a decontamination factor larger than 10. A new mechanical design of the Pd membrane reactor has been also developed: especially, harmful mechanical stresses of the long permeator tube consequent to the hydrogenation and thermal cycling has been avoided. Furthermore, an innovative effective heating system of the membrane has been also applied.

  1. CFD simulation on membrane distillation of NaCl solution

    Zhaoguang XU; Yanqiu PAN; Yalan YU

    2009-01-01

    A computational fluid dynamics (CFD) simu-lation that coupled an established heat and mass transfer model was carried out for the air-gap membrane distillation (AGMD) of NaCl solution to predict mass and heat behaviors of the process. The effects of temperature and flowrate on fluxes were first simulated and compared with available experimental data to verify the approach. The profiles of temperature, temperature polarization factor, and mass flux adjacent to the tubular carbon membrane surface were then examined under different feed Reynolds number in the computational domain. Results show that the temperature polarization phenomena can be reduced, and mass flux can be enhanced with increase in the feed Reynolds number.

  2. Genome-wide profiling to analyze the effects of FXR activation on mouse renal proximal tubular cells.

    Gui, Ting; Gai, Zhibo

    2015-12-01

    To assess the effect of farnesoid X receptor (FXR), a bile acid nuclear receptor, on renal proximal tubular cells, primary cultured mouse kidney proximal tubular cells were treated with GW4064 (a FXR agonist) or DMSO (as controls) overnight. Analysis of gene expression in the proximal tubular cells by whole genome microarrays indicated that FXR activation induced genes involved in fatty acid degradation and oxidation reduction. Among them, genes involved in glutathione metabolism were mostly induced. Here we describe in details the contents and quality controls for the gene expression and related results associated with the data uploaded to Gene Expression Omnibus (accession number GSE70296). PMID:26697325

  3. Genome-wide profiling to analyze the effects of FXR activation on mouse renal proximal tubular cells

    Ting Gui

    2015-12-01

    Full Text Available To assess the effect of farnesoid X receptor (FXR, a bile acid nuclear receptor, on renal proximal tubular cells, primary cultured mouse kidney proximal tubular cells were treated with GW4064 (a FXR agonist or DMSO (as controls overnight. Analysis of gene expression in the proximal tubular cells by whole genome microarrays indicated that FXR activation induced genes involved in fatty acid degradation and oxidation reduction. Among them, genes involved in glutathione metabolism were mostly induced. Here we describe in details the contents and quality controls for the gene expression and related results associated with the data uploaded to Gene Expression Omnibus (accession number GSE70296.

  4. Erythrocyte membrane proteins and membrane skeleton

    LU Yiqin; LIU Junfan

    2007-01-01

    Considerable advances in the research field of erythrocyte membrane were achieved in the recent two decades.New findings in the structure-function correlation and interactions of erythrocyte membrane proteins have attracted extensive attention.Interesting progress was also made in the molecular pathogenesis of erythrocyte membrane disorders.Advances in the composition,function and interaction of erythrocyte membrane proteins,erythrocyte membrane skeleton,and relevant diseases are briefly described and summarized here on the basis of domestic and world literatures.

  5. Microendoscopic Removal of Deep-Seated Brain Tumors Using Tubular Retraction System.

    Ratre, Shailendra; Yadav, Yad Ram; Parihar, Vijay Singh; Kher, Yatin

    2016-07-01

    Background Retraction of the overlying brain can be difficult without causing significant trauma when using traditional brain retractors with blades. These retractors may produce focal pressure and may result in brain contusion or infarction. Tubular retractors offer the advantage of low retracting pressure that is less likely to be traumatic. Low retraction pressure in the tubular retractor is due to the distribution of retraction force in all directions in a larger area. Material and Methods We conducted a retrospective study of 100 patients with deep-seated tumors operated on from January 2010 to December 2014. Tumor removal was accomplished with the help of a microscope and/or endoscope. Tubular brain retractors sizes 23, 18, and 15 mm were used. Folding of the tubular retractor after making a longitudinal cut allowed a small corticectomy. Larger retractor sizes were used in the earlier part of the study and in larger tumors. All the patients were evaluated postoperatively by computed tomography scan on the first postoperative day, and subsequent scans were done as and when needed. Any brain contusion or infarctions and the amount of tumor removal were recorded. Results A total of 74 patients had astrocytomas; 12, meningiomas; 4, colloid cyst of the third ventricle; 4, metastases; 4, primitive neuroectodermal tumor; 1, neurocytoma; and 1, ependymoma. Pure endoscopic excision without using a microscope was performed in 12 patients. Lesions were in the frontal (n = 34), parietal (n = 22), intraventricular (n = 16), basal ganglion or thalamic (n = 14), occipital (n = 10), and cerebellar (n = 4) areas. Total, near-total, and partial excision was achieved in 49, 29, and 22 patients, respectively. Use of a conventional retractor for excision of peripheral and superficial parts of a large tumor, small brain contusions, and technical failure were observed in 7, 4, and 1 patient, respectively. The low incidence of contusion may be partly

  6. Correlative Light-Electron Microscopy Reveals the Tubular-Saccular Ultrastructure of Carriers Operating between Golgi Apparatus and Plasma Membrane

    Polishchuk, Roman S.; Polishchuk, Elena V.; Marra, Pierfrancesco; Alberti, Saverio; Buccione, Roberto; Luini, Alberto; Mironov, Alexander A.

    2000-01-01

    Transport intermediates (TIs) have a central role in intracellular traffic, and much effort has been directed towards defining their molecular organization. Unfortunately, major uncertainties remain regarding their true structure in living cells. To address this question, we have developed an approach based on the combination of the green fluorescent protein technology and correlative light-electron microscopy, by which it is possible to monitor an individual carrier in vivo and then take a p...

  7. Efektivitas Membran Amnion Liofilisasi (Handmade Tubular) sebagai Nerve Conduit pada Perbaikan Cedera Saraf Perifer Tikus dengan Gap 5 mm

    R. Dadan G. Gandadikusumah; Hermawan N. Rasyid; Nucki N. Hidajat; Yoyos D. Ismiarto

    2013-01-01

    Peripheral nerve injury with 5–30 mm gap which is caused by direct injury cases (87%) or iatrogenic (12%) become a special concern because it could cause a serious disability in the future. Therefore, we need many kinds of nerve repair methods without adding morbidity to the patient. One of the methods is entubulation method, by using natural or synthetic material. This was an animal experimental research by using simple random design in Departement Pharmachology Laboratory, Faculty of Medici...

  8. A membrane disdrometer based on membrane vibration

    Raindrop sizes were indirectly determined through the distinctive vibrations and sounds that occur when raindrops of different sizes impact on a membrane. The relationships between diameter, raindrop kinetic momentum, membrane deflection, and impact force were analyzed. Membrane deflection and vibration models were created, and the optimum membrane diameter and thickness were identified. A prototype membrane disdrometer was developed on the basis of these findings. The relationship between raindrop size and membrane vibration sound pressure was determined experimentally. The fundamental parameter of raindrop size recognition was used. The test results indicate that raindrops 0.4–2.0 mm in diameter can be detected by the proposed membrane disdrometer, and 50 raindrops per second in a zone area of 28.3 cm2 can be detected in natural rain. (paper)

  9. A CFD study of hygro-thermal stresses distribution in tubular-shaped ambient air-breathing PEM micro fuel cell during regular cell operation

    Al-Baghdadi, Maher A.R. Sadiq [Fuel Cell Research Center, International Energy and Environment Foundation, Al-Najaf, P.O. Box 39 (Iraq)

    2010-07-01

    The need for improved lifetime of air-breathing proton exchange membrane (PEM) fuel cells for portable applications necessitates that the failure mechanisms be clearly understood and life prediction models be developed, so that new designs can be introduced to improve long-term performance. An operating air-breathing PEM fuel cell has varying local conditions of temperature, humidity. As a result of in the changes in temperature and moisture, the membrane, GDL and bipolar plates will all experience expansion and contraction. Because of the different thermal expansion and swelling coefficients between these materials, hygro-thermal stresses are introduced into the unit cell during operation. In addition, the non-uniform current and reactant flow distributions in the cell result in non-uniform temperature and moisture content of the cell which could in turn, potentially causing localized increases in the stress magnitudes, and this leads to mechanical damage, which can appear as through-the-thickness flaws or pinholes in the membrane, or delaminating between the polymer membrane and gas diffusion layers. Therefore, in order to acquire a complete understanding of these damage mechanisms in the membranes and gas diffusion layers, mechanical response under steady-state hygro-thermal stresses should be studied under real cell operation conditions. A three-dimensional, multi-phase, non-isothermal computational fluid dynamics model of a novel, tubular, ambient air-breathing, proton exchange membrane micro fuel cell has been developed and used to investigate the displacement, deformation, and stresses inside the whole cell, which developed during the cell operation due to the changes of temperature and relative humidity. The behaviour of the fuel cell during operation has been studied and investigated under real cell operating conditions. In addition to the new and complex geometry, a unique feature of the present model is to incorporate the effect of mechanical, hygro and

  10. A CFD study of hygro-thermal stresses distribution in tubular-shaped ambient air-breathing PEM micro fuel cell during regular cell operation

    Maher A.R. Sadiq Al-Baghdadi

    2010-03-01

    Full Text Available The need for improved lifetime of air-breathing proton exchange membrane (PEM fuel cells for portable applications necessitates that the failure mechanisms be clearly understood and life prediction models be developed, so that new designs can be introduced to improve long-term performance. An operating air-breathing PEM fuel cell has varying local conditions of temperature, humidity. As a result of in the changes in temperature and moisture, the membrane, GDL and bipolar plates will all experience expansion and contraction. Because of the different thermal expansion and swelling coefficients between these materials, hygro-thermal stresses are introduced into the unit cell during operation. In addition, the non-uniform current and reactant flow distributions in the cell result in non-uniform temperature and moisture content of the cell which could in turn, potentially causing localized increases in the stress magnitudes, and this leads to mechanical damage, which can appear as through-the-thickness flaws or pinholes in the membrane, or delaminating between the polymer membrane and gas diffusion layers. Therefore, in order to acquire a complete understanding of these damage mechanisms in the membranes and gas diffusion layers, mechanical response under steady-state hygro-thermal stresses should be studied under real cell operation conditions. A three-dimensional, multi–phase, non-isothermal computational fluid dynamics model of a novel, tubular, ambient air-breathing, proton exchange membrane micro fuel cell has been developed and used to investigate the displacement, deformation, and stresses inside the whole cell, which developed during the cell operation due to the changes of temperature and relative humidity. The behaviour of the fuel cell during operation has been studied and investigated under real cell operating conditions. In addition to the new and complex geometry, a unique feature of the present model is to incorporate the effect of

  11. A reduced graphene oxide nanofiltration membrane intercalated by well-dispersed carbon nanotubes for drinking water purification

    Chen, Xianfu; Qiu, Minghui; Ding, Hao; Fu, Kaiyun; Fan, Yiqun

    2016-03-01

    In this study, we report a promising rGO-CNT hybrid nanofiltration (NF) membrane that was fabricated by loading reduced graphene oxide that was intercalated with carbon nanotubes (rGO-CNTs) onto an anodic aluminum oxide (AAO) microfiltration membrane via a facile vacuum-assisted filtration process. To create this NF membrane, the CNTs were first dispersed using block copolymers (BCPs); the effects of the types and contents of BCPs used on the dispersion of CNTs have been investigated. The as-prepared rGO-CNT hybrid NF membranes were then used for drinking water purification to retain the nanoparticles, dyes, proteins, organophosphates, sugars, and particularly humic acid. Experimentally, it is shown that the rGO-CNT hybrid NF membranes have high retention efficiency, good permeability and good anti-fouling properties. The retention was above 97.3% even for methyl orange (327 Da); for other objects, the retention was above 99%. The membrane's permeability was found to be as high as 20-30 L m-2 h-1 bar-1. Based on these results, we can conclude that (i) the use of BCPs as a surfactant can enhance steric repulsion and thus disperse CNTs effectively; (ii) placing well-dispersed 1D CNTs within 2D graphene sheets allows an uniform network to form, which can provide many mass transfer channels through the continuous 3D nanostructure, resulting in the high permeability and separation performance of the rGO-CNT hybrid NF membranes.In this study, we report a promising rGO-CNT hybrid nanofiltration (NF) membrane that was fabricated by loading reduced graphene oxide that was intercalated with carbon nanotubes (rGO-CNTs) onto an anodic aluminum oxide (AAO) microfiltration membrane via a facile vacuum-assisted filtration process. To create this NF membrane, the CNTs were first dispersed using block copolymers (BCPs); the effects of the types and contents of BCPs used on the dispersion of CNTs have been investigated. The as-prepared rGO-CNT hybrid NF membranes were then used for

  12. Angiotensin II-induced mitochondrial Nox4 is a major endogenous source of oxidative stress in kidney tubular cells.

    Su-Mi Kim

    Full Text Available Angiotensin II (Ang II-induced activation of nicotinamide adenine dinucleotide phosphate (NAD(PH oxidase leads to increased production of reactive oxygen species (ROS, an important intracellular second messenger in renal disease. Recent findings suggest that Ang II induces mitochondrial depolarization and further amplifies mitochondrial generation of ROS. We examined the hypothesis that ROS injury mediated by Ang II-induced mitochondrial Nox4 plays a pivotal role in mitochondrial dysfunction in tubular cells and is related to cell survival. In addition, we assessed whether angiotensin (1-7 peptide (Ang-(1-7 was able to counteract Ang II-induced ROS-mediated cellular injury. Cultured NRK-52E cells were stimulated with 10(-6 M Ang II for 24 h with or without Ang-(1-7 or apocynin. Ang II simulated mitochondrial Nox4 and resulted in the abrupt production of mitochondrial superoxide (O(2 (- and hydrogen peroxide (H(2O(2. Ang II also induced depolarization of the mitochondrial membrane potential, and cytosolic secretion of cytochrome C and apoptosis-inducing factor (AIF. Ang-(1-7 attenuated Ang II-induced mitochondrial Nox4 expression and apoptosis, and its effect was comparable to that of the NAD(PH oxidase inhibitor. These findings suggest that Ang II-induced activation of mitochondrial Nox4 is an important endogenous source of ROS, and is related to cell survival. The ACE2-Ang-(1-7-Mas receptor axis should be investigated further as a novel target of Ang II-mediated ROS injury.

  13. Mucinous tubular and spindle cell carcinoma of the kidney: Diagnosis by fine needle aspiration and review of the literature

    Jiang Huimiao

    2015-01-01

    Full Text Available Renal mucinous tubular and spindle cell carcinoma (MTSCC was recently described as a distinct subtype of renal cell carcinoma (RCC in the 2004 World Health Organization classification of kidney tumors. MTSCC is a rare low grade malignancy with < 100 cases reported in the literature. To the best of our knowledge, there are 5 case reports with a total of 6 patients describing its diagnosis by fine needle aspiration (FNA. All of these cases were diagnosed as conventional RCC on FNA. Subsequent excisions proved them to be MTSCC. We herein report a case in a 67-year-old male. He presented with abdominal pain and was found to have a new colon adenocarcinoma with metastasis to the liver and lungs. The extent of disease made the patient ineligible for surgical excision, and he received chemotherapy. Work-up also revealed a kidney mass which was later biopsied by FNA and core biopsy. The tumor was composed of epithelial and spindled cell components embedded in a myxoid background. It was positive for CK7, AMCAR, vimentin, and epithelial membrane antigen. The tumor was diagnosed as MTSCC. One year later the kidney mass remained stable. However, the patient developed new metastasis to the liver from colonic primary. The kidney mass was not resected. Although rarely encountered in FNA cytology of the kidney, we believe the cytologic features of this tumor are distinctive and are different from conventional and other subtypes of RCC. Therefore, its accurate diagnosis on FNA is possible once pathologists are aware that MTSCC should be considered in the differential diagnosis of kidney tumors.

  14. A comparative study of MRI findings of experimentally induced rapid progressive glomerulonephritis (RPGN) and acute tubular necrosis (ATN) in rabbits

    To evaluate the usefulness of MR imaging in the differential diagnosis of the underlying causes of early-stage acute renal failure (ARF) by comparing the MRI findings of experimentally-induced crescentic glomerulonephritis (CGN) and acute tubular necrosis (ATN) in rabbits. Experimental CGN was induced by injecting anti-glomerular basement membrane antibody into six rabbits, and ATN by injecting glycerol solution into six rabbits. A normal control group of three rabbits was also used. Renal MR imaging (T1-and T2-weighted coronal images and dynamic MRI : DMRI) was performed the day before, and one,four, and seven days after the induction of CGN; and immediately before, and four, and eight hours, and one, four, and seven days after the induction of ATN. Sequential renal gunbiopsies and blood sampling (serum creatinine, sCr) were performed. Renal area, corticomedullary differentiation (CMD), and the passage of Gd-DTPA (patter of dark band), as seen on MRI, were analyzed and correlated with serial change of sCr. In normal kidneys, CMD was clearly apparent on both T1-and T2-weighted images. DMRI demonstrated a progressively inwardly migrating dark band in the kidneys. CMD was relatively clearly demonstrated in the ATN group but less clearly identified in the CGN group. Renal size (area) and sCr gradually increased in both the CGN and ATN groups, and dark bands were moderately to poorly defined in both. We conclude that DMRI could be used to differentiate and evaluate disease processing and compromised renal function in cases of CGN and ATN. On T1-and T2-weighted images, CMD was relatively well preserved in the ATN group, but was less clear in the CGN group. These MRI findings may be helpful for differentiation of the underlying causes of early-stage ARF, particularly between CGN and ATN

  15. Membranes for hydrogen and fuel cell technology; Membranas para celula combustivel e separacao de hidrogenio

    Nunes, Suzana Pereira [GKSS-Forschungszentrum, Geesthacht (Germany)]. E-mail: nunes@gkss.de

    2005-07-01

    Membranes for fuel cell were prepared using as polymer matrix sulfonated polyether ketones. New sulfonated copolymers (poly oxazoles, poly imides and poly ketones) were synthesized. Nano composites using zirconium oxide and phosphates, as well as modified silicates were obtained aiming the application on direct methanol fuel cell (DMFC). The performances of membranes containing fillers with different aspects (spherical, layers, tubular, networks) and surface modification (hydroxy, imidazole, acid oligomers) were compared. The effect of surface modification was much more pronounced than that of the aspect. A good balance of proton conductivity and methanol permeability was obtained with silicates modified with imidazole groups. Good performance in DMFC were obtained with membranes containing zirconium phosphate. Acid oligomers also led to particularly high conductivity values above 100 deg C. Polyimide membranes with H{sub 2}/CH{sub 4} larger than 100 were obtained. (author )

  16. Membrane reforming in converting natural gas to hydrogen: Production costs, Part II

    Iaquaniello, G.; Cosenza, S. [Technip-KTI S.p.A., via Castello della Magliana 75, Rome (Italy); Giacobbe, F.; Morico, B.; Farace, A. [Processi Innovativi s.r.l., L' Aquila (Italy)

    2008-11-15

    This paper evaluates the production costs of a hybrid system based on a new membrane reforming MRR concept to convert natural gas to hydrogen and electricity. Membrane reforming with hydrogen-selective, palladium-silver membranes pushes the chemical equilibrium and allows higher methane conversions at lower temperature such as 650 C. The new MRR concept formed of a series of modules is put forward herein. Each module is made up of a reforming step and an external membrane separation unit. The estimates, based on utilities costs of a typical Italian refinery (end of 2006), show that the production costs for the hybrid system are 30% less than conventional tubular steam reforming technology, and 13% less than a gas-fired cogeneration plant coupled with a conventional H{sub 2} plant. (author)

  17. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration

    Mehrdad Ebrahimi

    2015-12-01

    Full Text Available Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively.

  18. Endocytic proteins drive vesicle growth via instability in high membrane tension environment

    Walani, Nikhil; Agrawal, Ashutosh

    2015-01-01

    Clathrin-mediated endocytosis (CME) is a key pathway for transporting cargo into cells via membrane vesicles. It plays an integral role in nutrient import, signal transduction, neurotransmission and cellular entry of pathogens and drug-carrying nanoparticles. As CME entails substantial local remodeling of the plasma membrane, the presence of membrane tension offers resistance to bending and hence, vesicle formation. Experiments show that in such high tension conditions, actin dynamics is required to carry out CME successfully. In this study, we build upon these pioneering experimental studies to provide fundamental mechanistic insights into the roles of two key endocytic proteins, namely, actin and BAR proteins in driving vesicle formation in high membrane tension environment. Our study reveals a new actin force induced `snap-through instability' that triggers a rapid shape transition from a shallow invagination to a highly invaginated tubular structure. We show that the association of BAR proteins stabilizes...

  19. Magnetically controlled permeability membranes

    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.

  20. Compositional asynchronous membrane systems

    Cosmin Bonchis; Cornel Izbasa; Gabriel Ciobanu

    2007-01-01

    This paper presents an algorithmic way of building complex membrane systems by coupling elementary membranes. Its application seems particularly valuable in the case of asynchronous membrane systems, since the resulting membrane system remains asynchronous. The composition method is based on a handshake mechanism implemented by using antiport rules and promoters.