WorldWideScience

Sample records for type tubular recuperative

  1. Efficiency enhancement of a gas turbine cycle using an optimized tubular recuperative heat exchanger

    International Nuclear Information System (INIS)

    Sayyaadi, Hoseyn; Mehrabipour, Reza

    2012-01-01

    A simple gas turbine cycle namely as the Kraftwerk Union AG unit including a Siemens gas turbine model V93.1 with 60 MW nominal power and 26.0% thermal efficiency utilized in the Fars power plant located is considered for the efficiency enhancement. A typical tubular vertical recuperative heat exchanger is designed in order to integrate into the cycle as an air pre-heater for thermal efficiency improvement. Thermal and geometric specifications of the recuperative heat exchanger are obtained in a multi-objective optimization process. The exergetic efficiency of the gas cycle is maximized while the payback time for the capital investment of the recuperator is minimized. Combination of these objectives and decision variables with suitable engineering and physical constraints makes a set of the MINLP optimization problem. Optimization programming is performed using the NSGA-II algorithm and Pareto optimal frontiers are obtained in three cases including the minimum, average and maximum ambient air temperatures. In each case, the final optimal solution has been selected using three decision-making approaches including the fuzzy Bellman-Zadeh, LINMAP and TOPSIS methods. It has been shown that the TOPSIS and LINMAP decision-makers when applied on the Pareto frontier which is obtained at average ambient air temperature yields best results in comparison to other cases. -- Highlights: ► A simple Brayton gas cycle is considered for the efficiency improvement by integrating of a recuperator. ► Objective functions based on thermodynamic and economic analysis are obtained. ► The payback time for the capital investment is minimized and the exergetic efficiency of the system is maximized. ► Pareto optimal frontiers at various site conditions are obtained. ► A final optimal configuration is found using various decision-making approaches.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Heavy water moderated tubular type nuclear reactor

    International Nuclear Information System (INIS)

    Oohashi, Masahisa.

    1986-01-01

    Purpose: To enable to effectively change the volume of heavy water per unit fuel lattice in heavy water moderated pressure tube type nuclear reactors. Constitution: In a nuclear reactor in which fuels are charged within pressure tubes and coolants are caused to flow between the pressure tubes and the fuels, heavy water tubes for recycling heavy water are disposed to a gas region formed to the outside of the pressure tubes. Then, the pressure tube diameter at the central portion of the reactor core is made smaller than that at the periphery of the reactor core. Further, injection means for gas such as helium is disposed to the upper portion for each of the heavy water tubes so that the level of the heavy water can easily be adjusted by the control for the gas pressure. Furthermore, heavy water reflection tubes are disposed around the reactor core. In this constitution, since the pitch for the pressure tubes can be increased, the construction and the maintenance for the nuclear reactor can be facilitated. Also, since the liquid surface of the heavy water in the heavy water tubes can be varied, nuclear properties is improved and the conversion ratio is improved. (Ikeda, J.)

  4. Non-catalytic recuperative reformer

    Science.gov (United States)

    Khinkis, Mark J.; Kozlov, Aleksandr P.; Kurek, Harry

    2015-12-22

    A non-catalytic recuperative reformer has a flue gas flow path for conducting hot flue gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is embedded in the flue gas flow path to permit heat transfer from the hot flue gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorific fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, extended surfaces of metal material such as stainless steel or metal alloy that are high in nickel content are included within at least a portion of the reforming mixture flow path.

  5. Bioinspired coupled helical coils for soft tissue engineering of tubular structures - Improved mechanical behavior of tubular collagen type I templates.

    Science.gov (United States)

    Janke, H P; Bohlin, J; Lomme, R M L M; Mihaila, S M; Hilborn, J; Feitz, W F J; Oosterwijk, E

    2017-09-01

    The design of constructs for tubular tissue engineering is challenging. Most biomaterials need to be reinforced with supporting structures such as knittings, meshes or electrospun material to comply with the mechanical demands of native tissues. In this study, coupled helical coils (CHCs) were manufactured to mimic collagen fiber orientation as found in nature. Monofilaments of different commercially available biodegradable polymers were wound and subsequently fused, resulting in right-handed and left-handed polymer helices fused together in joints where the filaments cross. CHCs of different polymer composition were tested to determine the tensile strength, strain recovery, hysteresis, compressive strength and degradation of CHCs of different composition. Subsequently, seamless and stable hybrid constructs consisting of PDSII® USP 2-0 CHCs embedded in porous collagen type I were produced. Compared to collagen alone, this hybrid showed superior strain recovery (93.5±0.9% vs 71.1±12.6% in longitudinal direction; 87.1±6.6% vs 57.2±4.6% in circumferential direction) and hysteresis (18.9±2.7% vs 51.1±12.0% in longitudinal direction; 11.5±4.6% vs 46.3±6.3% in circumferential direction). Furthermore, this hybrid construct showed an improved Young's modulus in both longitudinal (0.5±0.1MPavs 0.2±0.1MPa; 2.5-fold) and circumferential (1.65±0.07MPavs (2.9±0.3)×10 -2 MPa; 57-fold) direction, respectively, compared to templates created from collagen alone. Moreover, hybrid template characteristics could be modified by changing the CHC composition and CHCs were produced showing a mechanical behavior similar to the native ureter. CHC-enforced templates, which are easily tunable to meet different demands may be promising for tubular tissue engineering. Most tubular constructs lack sufficient strength and tunability to comply with the mechanical demands of native tissues. Therefore, we embedded coupled helical coils (CHCs) produced from biodegradable polymers - to

  6. Interrogating Recuperative Masculinity Politics in Schooling

    Science.gov (United States)

    Lingard, Bob; Mills, Martin; Weaver-Hightower, Marcus B.

    2012-01-01

    This article focuses on the continuing impact of recuperative masculinity politics in the schooling of economically advantaged boys (elite and middle class); yet, it also indicates resistance to this politics. An understanding that the gender order is unstable and that variants of hegemonic masculinity continue to morph in the context of…

  7. CREATION OF OPTIMIZATION MODEL OF STEAM BOILER RECUPERATIVE AIR HEATER

    Directory of Open Access Journals (Sweden)

    N. B. Carnickiy

    2006-01-01

    Full Text Available The paper proposes to use a mathematical modeling as one of the ways intended to improve quality of recuperative air heater design (RAH without significant additional costs, connected with the change of design materials or fuel type. The described conceptual mathematical AHP optimization model of RAH consists of optimized and constant parameters, technical limitations and optimality criteria.The paper considers a methodology for search of design and regime parameters of an air heater which is based on the methods of multi-criteria optimization. Conclusions for expediency of the given approach usage are made in the paper.

  8. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru

    2014-01-01

    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  9. Measurement of the Velocity and Pressure Drop in a Tubular Type Fuel

    International Nuclear Information System (INIS)

    Jonghark Park; Heetaek Chae; Cheol Park; Heonil Kim

    2006-01-01

    We have developed a tubular type fuel assembly design as one of candidates for fuel to be used in the Advanced HANARO Reactor (AHR). The tubular type fuel has several merits over a rod type fuel with respect to the thermal-hydraulic and structural safety; the larger ratio of surface area to volume makes the surface temperature of a fuel element become lower, and curved plate is stronger against longitudinal bending and vibration. In the other side, a disadvantage is expected such that the flow velocity can be distributed unevenly channel by channel because the flow channels are isolated from each other in a tubular type fuel assembly. In addition to the design development, we also investigated the flow characteristics of the tubular fuel experimentally. To examine the flow velocity distribution and pressure drop, we made an experiment facility and a mockup of the tubular fuel assembly. The fuel assembly consists of 6 concentric fuel tubes so that 7 layers are made between fuel tubes. Since each layer is divided into three sections by stiffeners, 21 isolated flow channels are made in total. We employed pitot-tubes to measure the coolant velocity in each channel. The maximum velocity was measured as large as about 28% of the average velocity. It was observed in the innermost channel contrarily to the expectation from the hydraulic diameter. A change in the total flow rate did not affect the flow distribution. Meanwhile, the pressure drop was measured as about 70% of the drop in the rod type fuel assembly in use in HANARO. (authors)

  10. Distal renal tubular acidosis

    Science.gov (United States)

    ... this disorder. Alternative Names Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA Images Kidney anatomy Kidney - blood and urine flow References Bose A, Monk RD, Bushinsky DA. Kidney ...

  11. Radiant non-catalytic recuperative reformer

    Energy Technology Data Exchange (ETDEWEB)

    Khinkis, Mark J.; Kozlov, Aleksandr P.

    2017-10-31

    A radiant, non-catalytic recuperative reformer has a flue gas flow path for conducting hot exhaust gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is positioned adjacent to the flue gas flow path to permit heat transfer from the hot exhaust gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorific fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, a portion of the reforming mixture flow path is positioned outside of flue gas flow path for a relatively large residence time.

  12. Cleistanthus collinus induces type I distal renal tubular acidosis and type II respiratory failure in rats.

    Science.gov (United States)

    Maneksh, Delinda; Sidharthan, Anita; Kettimuthu, Kavithapriya; Kanthakumar, Praghalathan; Lourthuraj, Amala A; Ramachandran, Anup; Subramani, Sathya

    2010-06-01

    A water decoction of the poisonous shrub Cleistanthus collinus is used for suicidal purposes. The mortality rate is 28%. The clinical profile includes distal renal tubular acidosis (DRTA) and respiratory failure. The mechanism of toxicity is unclear. To demonstrate features of C. collinus toxicity in a rat model and to identify its mechanism(s) of action. Rats were anesthetized and the carotid artery was cannulated. Electrocardiogram and respiratory movements were recorded. Either aqueous extract of C. collinus or control solution was administered intraperitoneally. Serial measurements of blood gases, electrolytes and urinary pH were made. Isolated brush border and basolateral membranes from rat kidney were incubated with C. collinus extract and reduction in ATPase activity was assessed. Venous blood samples from human volunteers and rats were incubated with an acetone extract of C. collinus and plasma potassium was estimated as an assay for sodium-potassium pump activity. The mortality was 100% in tests and 17% in controls. Terminal event in test animals was respiratory arrest. Controls had metabolic acidosis, respiratory compensation acidic urine and hyperkalemia. Test animals showed respiratory acidosis, alkaline urine and low blood potassium as compared to controls. C. collinus extract inhibited ATPase activity in rat kidney. Plasma K(+) did not increase in human blood incubated with C. collinus extract. Active principles of C. collinus inhibit proton pumps in the renal brush border, resulting in type I DRTA in rats. There is no inhibition of sodium-potassium pump activity. Test animals develop respiratory acidosis, and the immediate cause of death is respiratory arrest.

  13. Optimal hydraulic design of new-type shaft tubular pumping system

    International Nuclear Information System (INIS)

    Zhu, H G; Zhang, R T; Zhou, J R

    2012-01-01

    Based on the characteristics of large flow rate, low-head, short annual operation time and high reliability of city flood-control pumping stations, a new-type shaft tubular pumping system featuring shaft suction box, siphon-type discharge passage with vacuum breaker as cutoff device was put forward, which possesses such advantages as simpler structure, reliable cutoff and higher energy performance. According to the design parameters of a city flood control pumping station, a numerical computation model was set up including shaft-type suction box, siphon-type discharge passage, pump impeller and guide vanes. By using commercial CFD software Fluent, RNG κ-ε turbulence model was adopted to close the three-dimensional time-averaged incompressible N-S equations. After completing optimal hydraulic design of shaft-type suction box, and keeping the parameters of total length, maximum width and outlet section unchanged, siphon-type discharge passages of three hump locations and three hump heights were designed and numerical analysis on the 9 hydraulic design schemes of pumping system were proceeded. The computational results show that the changing of hump locations and hump heights directly affects the internal flow patterns of discharge passages and hydraulic performances of the system, and when hump is located 3.66D from the inlet section and hump height is about 0.65D (D is the diameter of pump impeller), the new-type shaft tubular pumping system achieves better energy performances. A pumping system model test of the optimal designed scheme was carried out. The result shows that the highest pumping system efficiency reaches 75.96%, and when at design head of 1.15m the flow rate and system efficiency were 0.304m 3 /s and 63.10%, respectively. Thus, the validity of optimal design method was verified by the model test, and a solid foundation was laid for the application and extension of the new-type shaft tubular pumping system.

  14. Analysis of a pico tubular-type hydro turbine performance by runner blade shape using CFD

    Science.gov (United States)

    Park, J. H.; Lee, N. J.; Wata, J. V.; Hwang, Y. C.; Kim, Y. T.; Lee, Y. H.

    2012-11-01

    There has been a considerable interest recently in the topic of renewable energy. This is primarily due to concerns about environmental impacts of fossil fuels. Moreover, fluctuating and rising oil prices, increase in demand, supply uncertainties and other factors have led to increased calls for alternative energy sources. Small hydropower, among other renewable energy sources, has been evaluated to have adequate development value because it is a clean, renewable and abundant energy resource. In addition, small hydropower has the advantage of low cost development by using rivers, agricultural reservoirs, sewage treatment plants, waterworks and water resources. The main concept of the tubular-type hydro turbine is based on the difference in water pressure levels in pipe lines, where the energy which was initially wasted by using a reducing valve at the pipeline of waterworks, is collected by turbine in the hydro power generator. In this study, in order to acquire the performance data of a pico tubular-type hydro turbine, the output power, head and efficiency characteristics by different runner blade shapes are examined. The pressure and velocity distributions with the variation of guide vane and runner vane angle on turbine performance are investigated by using a commercial CFD code.

  15. Renal functional reserve and tubular function in patents with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Dilyara Makhmutrievna Khakimova

    2011-06-01

    Full Text Available Aim. To study renal functional reserve and partial functions in patents with type 2 diabetes mellitus in the absence of renal lesionsMaterials and methods. We examined 42 patients (17 men and 24 women aged 38-69 (mean 49.8?8.3 years with DM2 4.6?2.6 yr in duration.Control group comprised 32 practically healthy subjects. Intrarenal hemodynamics was estimated from RFR values. Ethanolamine, uric acid, Ca,and P levels were measured in sera and 24-hr urine; daily excretion of ammonia and aminonitrogen in the urine was determined. Results. The patients were divided into 2 groups based on the results of RFR measurement. FRF remained unaltered in 21 patients (mean 60.7?27.6%and decreased in the absence of filtration reserve in 20 (-25.8?23.4%. Correlation analysis revealed the relationship of lipid metabolism and abdominalobesity with the renal tubular function and intraglomerular hemodynamics. Conclusion. Examination of DM2 patients without clinical and laboratory signs of renal lesions revealed compromised function of all nephron compartments,viz. intraglomerular hypertension, impaired stability of renal cell membranes, and tubular dysfunction. The latter is related to hemodynamic disturbances.

  16. Transcatheter closure of tubular type patent ductus arteriosus using Amplatzer® ductal occluder II: a case report

    Directory of Open Access Journals (Sweden)

    Mulyadi M Djer

    2013-10-01

    In recent years, interventional cardiology has become a gold standard therapy for the majority of PDA cases beyond neonatal age. Since its introduction in 1967, many devices and methods have been developed to allow transcatheter closure of virtually all PDAs, regardless of size or configuration. Nevertheless, the tubular shape (type C PDA, which has the highest residual shunt rate, still poses a great challenge for the interventionist.8-10 The second generation of Amplatzer® device occluders (ADO II, released in 2007, has been suggested to be effective in closing tubular PDAs.10 The purpose of this study was to report the initial clinical experience using ADO II to close a tubular type PDA in Indonesia.

  17. Treatment of radioactive liquid waste by tubular type reverse osmosis module

    International Nuclear Information System (INIS)

    Nishimaki, Kenzo; Koyama, Akio; Tsutsui, Tenson; Mori, Koji.

    1988-01-01

    The applicability of reverse osmosis to radioactive liquid waste treatment was studied using a tubular type module. When four modules were used in a series, circulating volume of concentrate was much greater than permeate volume, therefore solute concentration and circulating rate of concentrate can be assumed uniform in the axial direction of the modules. DFs of stable elements contained in the tap water were 36-40 for Na, 50-55 for K, 170-250 for Mg and 90-160 for Ca. When Na concentration increased about ten times, DFs for all elements slightly decreased. For actual liquid waste tagged with radionuclides, DFs were in the range of 35-40 for 134 Cs, 150-200 for 85 Sr, and 180-280 for 58 Co. These DF values indicate the possibility of the treatment of low radioactive liquid waste by reverse osmosis. (author)

  18. Performance analysis of a counter-rotating tubular type micro-turbine by experiment and CFD

    International Nuclear Information System (INIS)

    Lee, N J; Choi, J W; Hwang, Y H; Kim, Y T; Lee, Y H

    2012-01-01

    Micro hydraulic turbines have a growing interest because of its small and simple structure, as well as a high possibility of using in micro and small hydropower applications. The differential pressure existing in city water pipelines can be used efficiently to generate electricity in a way similar to that of energy being generated through gravitational potential energy in dams. The pressure energy in the city pipelines is often wasted by using pressure reducing valves at the inlet of water cleaning centers. Instead of using the pressure reducing valves, a micro counter-rotating hydraulic turbine can be used to make use of the pressure energy. In the present paper, a counter-rotating tubular type micro-turbine is studied, with the front runner connected to the generator stator and the rear runner connected to the generator rotor. The performance of the turbine is investigated experimentally and numerically. A commercial ANSYS CFD code was used for numerical analysis.

  19. Tubular-Type Hydroturbine Performance for Variable Guide Vane Opening by CFD

    Science.gov (United States)

    Kim, Y. T.; Nam, S. H.; Cho, Y. J.; Hwang, Y. C.; Choi, Y. D.; Nam, C. D.; Lee, Y. H.

    Micro hydraulic power generation which has output of less or equal to 100kW is attracting considerable attention. This is because of its small, simple, renewable, and large amount of energy resources. By using a small hydro power generator of which main concept is based on using differential water pressures in pipe lines, energy which was initially wasted by use of a reducing valve at an end of the pipeline, is collected by a turbine in the hydro power generator. A propeller shaped hydroturbine has been used in order to make use of this renewable pressure energy. In this study, in order to acquire basic design data of tubular type hydroturbine, output power, head, and efficiency characteristics due to the guide vane opening angle are examined in detail. Moreover, influences of pressure, tangential and axial velocity distributions on turbine performance are investigated by using a commercial CFD code.

  20. Systemic lupus erythematosus associated with type 4 renal tubular acidosis: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Young Larry

    2011-03-01

    Full Text Available Abstract Introduction Type 4 renal tubular acidosis is an uncommon clinical manifestation of systemic lupus erythematosus and has been reported to portend a poor prognosis. To the best of our knowledge, this is the first case report which highlights the successful management of a patient with systemic lupus erythematosus complicated by type 4 renal tubular acidosis who did not do poorly. Case presentation A 44-year-old Hispanic woman developed a non-anion gap hyperkalemic metabolic acidosis consistent with type 4 renal tubular acidosis while being treated in the hospital for recently diagnosed systemic lupus erythematosus with multi-organ involvement. She responded well to treatment with corticosteroids, hydroxychloroquine and mycophenolate mofetil. Normal renal function was achieved prior to discharge and remained normal at the patient's one-month follow-up examination. Conclusion This case increases awareness of an uncommon association between systemic lupus erythematosus and type 4 renal tubular acidosis and suggests a positive impact of early diagnosis and appropriate immunosuppressive treatment on the patient's outcome.

  1. Morphological characterization and topographic analysis of multiple photoreceptor types in the retinae of mesopelagic hatchetfishes with tubular eyes

    Directory of Open Access Journals (Sweden)

    Lauren Michelle Biagioni

    2016-03-01

    Full Text Available Marine hatchetfishes, Argyropelecus spp., are one of the 14 genera of mesopelagic teleosts, which possess tubular eyes. The tubular eyes are positioned dorsally on the head and consist of a main retina, which subtends a large dorsal binocular field, and an accessory retina, which subtends the lateral monocular visual field. The topographic distribution of photoreceptors in the retina of Argyropelecus sladeni, A. affinis and A. aculeatus was determined using a random, unbiased and systematic stereological approach, which consistently revealed a region of high density (area centralis in the central region of the main retina (up to a peak of 96,000 receptors per mm2 and a relatively homogeneous density of photoreceptors in the accessory retina (of approximately 20,000 receptors per mm2. The position of the area centralis in the main retina indicates this retinal region subserves greater spatial resolution in the centre of the dorsal binocular visual field. Light microscopy and transmission electron microscopy also revealed the presence of multiple photoreceptor types (two rod-like and one cone-like based on the size and shape of the inner and outer segments and ultrastructural differences in the ellipsoidal region. The presence of multiple photoreceptor types in these tubular-eyed, mesopelagic hatchetfishes may reflect the need for the visual system to function under different lighting conditions during vertical migratory behavior, especially given their unique dorsally-facing eyes.

  2. Expandable tubulars for use in geologic structures

    Science.gov (United States)

    Spray, Jeffery A.; Svedeman, Steven; Walter, David; Mckeighan, Peter; Siebanaler, Shane; Dewhurst, Peter; Hobson, Steven; Foss, Doug; Wirz, Holger; Sharpe, Aaron; Apostal, Michael

    2014-08-12

    An expandable tubular includes a plurality of leaves formed from sheet material that have curved surfaces. The leaves extend around a portion or fully around the diameter of the tubular structure. Some of the adjacent leaves of the tubular are coupled together. The tubular is compressed to a smaller diameter so that it can be inserted through previously deployed tubular assemblies. Once the tubular is properly positioned, it is deployed and coupled or not coupled to a previously deployed tubular assembly. The tubular is useful for all types of wells and boreholes.

  3. Synergy between type 1 fimbriae expression and C3 opsonisation increases internalisation of E. coli by human tubular epithelial cells.

    Science.gov (United States)

    Li, Ke; Zhou, Wuding; Hong, Yuzhi; Sacks, Steven H; Sheerin, Neil S

    2009-03-31

    Bacterial infection of the urinary tract is a common clinical problem with E. coli being the most common urinary pathogen. Bacterial uptake into epithelial cells is increasingly recognised as an important feature of infection. Bacterial virulence factors, especially fimbrial adhesins, have been conclusively shown to promote host cell invasion. Our recent study reported that C3 opsonisation markedly increases the ability of E. coli strain J96 to internalise into human proximal tubular epithelial cells via CD46, a complement regulatory protein expressed on host cell membrane. In this study, we further assessed whether C3-dependent internalisation by human tubular epithelial cells is a general feature of uropathogenic E. coli and investigated features of the bacterial phenotype that may account for any heterogeneity. In 31 clinical isolates of E. coli tested, C3-dependent internalisation was evident in 10 isolates. Type 1 fimbriae mediated-binding is essential for C3-dependent internalisation as shown by phenotypic association, type 1 fimbrial blockade with soluble ligand (mannose) and by assessment of a type 1 fimbrial mutant. we propose that efficient internalisation of uropathogenic E. coli by the human urinary tract depends on co-operation between type 1 fimbriae-mediated adhesion and C3 receptor -ligand interaction.

  4. Tubular markers do not predict the decline in glomerular filtration rate in type 1 diabetic patients with overt nephropathy

    DEFF Research Database (Denmark)

    Nielsen, Stine E; Andersen, Steen; Zdunek, Dietmar

    2011-01-01

    of neutrophil gelatinase-associated lipocalin (NGAL), liver-fatty acid-binding protein (LFABP), and kidney injury molecule-1 (KIM-1) in a 3-year intervention study of 63 type 1 diabetic patients with kidney disease. The baseline mean glomerular filtration rate (GFR) was 87 ml/min per 1.73 m(2) and urinary......Recent studies have shown that both glomerular and tubulointerstitial damage are important factors in the pathophysiology and progression of diabetic nephropathy. To examine whether markers of tubular damage are useful in monitoring the progression of disease, we measured urinary levels...

  5. Arch-Axis Coefficient Optimization of Long-Span Deck-Type Concrete-Filled Steel Tubular Arch Bridge

    Science.gov (United States)

    Liu, Q. J.; Wan, S.; Liu, H. C.

    2017-11-01

    This paper is based on Nanpuxi super major bridge which is under construction and starts from Wencheng Zhejiang province to Taishun highway. A finite element model of the whole bridge is constructed using Midas Civil finite element software. The most adverse load combination in the specification is taken into consideration to determine the method of calculating the arch-axis coefficient of long-span deck-type concrete-filled steel tubular arch bridge. By doing this, this paper aims at providing references for similar engineering projects.

  6. Heat transfer and thermal storage performance of an open thermosyphon type thermal storage unit with tubular phase change material canisters

    International Nuclear Information System (INIS)

    Wang, Ping-Yang; Hu, Bo-Wen; Liu, Zhen-Hua

    2015-01-01

    Highlights: • A novel open heat pipe thermal storage unit is design to improve its performance. • Mechanism of its operation is phase-change heat transfer. • Tubular canisters with phase change material were placed in thermal storage unit. • Experiment and analysis are carried out to investigate its operation properties. - Abstract: A novel open thermosyphon-type thermal storage unit is presented to improve design and performance of heat pipe type thermal storage unit. In the present study, tubular canisters filled with a solid–liquid phase change material are vertically placed in the middle of the thermal storage unit. The phase change material melts at 100 °C. Water is presented as the phase-change heat transfer medium of the thermal storage unit. The tubular canister is wrapped tightly with a layer of stainless steel mesh to increase the surface wettability. The heat transfer mechanism of charging/discharging is similar to that of the thermosyphon. Heat transfer between the heat resource or cold resource and the phase change material in this device occurs in the form of a cyclic phase change of the heat-transfer medium, which occurs on the surface of the copper tubes and has an extremely high heat-transfer coefficient. A series of experiments and theoretical analyses are carried out to investigate the properties of the thermal storage unit, including power distribution, start-up performance, and temperature difference between the phase change material and the surrounding vapor. The results show that the whole system has excellent heat-storage/heat-release performance

  7. Hydrogen production from biomass by thermochemical recuperative energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Fushimi, C.; Araki, K.; Yamaguchi, Y.; Tsutsumi, A. [Tokyo Univ. (Japan). Dept. of Chemical System Engineering

    2002-07-01

    The authors conducted, using a thermogravimetric reactor, a kinetic study of production of thermochemical recuperative hydrogen from biomass. The four different biomass materials used were: cellulose, lignin, metroxylon stem, and coconut husk. Under both rapid heating and slow heating conditions, the weight changes of the biomass samples during the steam gasification or pyrolysis were measured at 973 Kelvin. Simultaneously, measurements of the evolution rates of low-molecular-weight gas products such as hydrogen, methane, carbon monoxide, and carbon dioxide were taken with the help of a mass spectrometer and a micro gas chromatograph (GC). The steam gasification of char significantly increased the amount of hydrogen and carbon dioxide production. The results also indicated that at higher heating rate, the cold gas efficiency of steam gasification was increased. This can be explained by the suppression of the tar production at lower temperature. 25 refs., 2 tabs., 10 figs.

  8. Reliability of Tubular Joints

    DEFF Research Database (Denmark)

    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 the test is partly to obtain empirical data for the ultimate load-carrying capacity of tubular T-joints and partly to obtain some experience in performing tests with tubular joints. It is well known that tubular joints are usually designed in offshore engineering on the basis of empirical formulas obtained...... by experimental test results. Therefore, there is a need for performing experimental tests in this area....

  9. Feasibility analysis and performance characteristics investigation of spatial recuperative expander based on organic Rankine cycle for waste heat recovery

    International Nuclear Information System (INIS)

    Han, Yongqiang; Li, Runzhao; Liu, Zhongchang; Tian, Jing; Wang, Xianfeng; Kang, Jianjian

    2016-01-01

    Highlights: • A new concept of spatial recuperative expander for waste heat recovery is proposed. • Simulation model of spatial recuperative expander is established and verified. • The performance characteristics of spatial recuperative expander are investigated. • Comparison between spatial recuperative expander and traditional one is performed. • Spatial recuperative expander achieves better performance than traditional one. - Abstract: This paper proposes a new concept of spatial recuperative expander which injects cold refrigerant during exhaust stroke as a measure of direct contact heat transfer. The commercial simulation tool GT-SUIT 7.4 is employed to model and verify the feasibility of spatial recuperative expander. The research contents are comprised of the following aspects: Firstly, the principles and performance characteristics between traditional reciprocating piston expander and spatial recuperative expander have been investigated. Secondly, the potential of spatial recuperation by adjusting cold refrigerant injection timing has been studied. Thirdly, the relation between expander performance and variable expansion ratio under constant operating condition has been discussed. Fourthly, the thermodynamic performance of spatial recuperative expander under various operating conditions has been examined. The simulation results indicate that: Firstly, the torque per unit mass, thermal efficiency, exergetic efficiency, isentropic efficiency and recuperative efficiency of optimum spatial recuperative expander are 51.00%, 6.74%, 20.79%, 5.68% and 11.36% higher than traditional reciprocating piston expander respectively. Secondly, the cold refrigerant injection timing has little influence on recuperative efficiency because the recuperation process can complete within 16.67 ms. Thirdly, different operating conditions correspond to particular optimal expansion ratio. Fourthly, increasing the pump pressure and maintaining appropriate superheated degree

  10. H2S cracking resistance of type 420 stainless steel tubulars

    International Nuclear Information System (INIS)

    Klein, L.J.

    1984-01-01

    Type 420 stainless steel (13Cr) production tubing is being used successfully in deep sour gas wells in the Tuscaloosa Trend. Despite their reputation for poor H 2 S cracking resistance in laboratory tests, 12-13% Cr steels continue to perform well in sour environments. NACE Tensile Test and Shell bent beam test results indicate Type 420 is more resistant to H 2 S cracking than Type 410, but is not as resistant as carbon steel, at to 586-690 MPa (85-100 ksi) yield strength level. In addition to evaluating Type 420 stainless steel in the standard NACE Tensile and Shell bent beam tests, the effects on cracking tendency of chloride concentration, pH, and H 2 S gas concentration in the NACE Test solution were also examined. Type 420 appears to be more resistant to H 2 S cracking than is indicated by standard laboratory tests, at least in low H 2 S level sour environments

  11. Psychological and Psychophysiological Effects of Recuperative Music Postexercise.

    Science.gov (United States)

    Karageorghis, Costas I; Bruce, Andrew C; Pottratz, Suzanne T; Stevens, Rebecca C; Bigliassi, Marcelo; Hamer, Mark

    2018-04-01

    Few studies have examined the psychological and psychophysiological effects of recuperative music after exhaustive exercise. The main purpose of the present study was to examine the effects of two music conditions compared with a no-music control on psychological and psychophysiological recovery processes after exercise. A randomized, fully counterbalanced, crossover design was used. Core affect, salivary cortisol, heart rate, and blood pressure were measured before exhaustive exercise, immediately after, and in 10-, 20-, and 30-min intervals during passive recovery (21 women and 21 men; 20.9 ± 1.7 yr) over three separate trials (slow, sedative music; fast, stimulative music; no-music control). The exercise task entailed incremental cycle ergometry performed at 75 rpm with an increase in intensity of 22.5 W·min at the end of each minute until exhaustion. Data were analyzed using mixed-model 3 (condition) × 4 (time) × 2 (gender) MANOVA/ANCOVA. The largest decline in affective arousal between active and passive recovery phases was evident in the slow, sedative condition (ηp = 0.50). Women had a more pronounced reduction in arousal than did men in the slow, sedative music condition. Heart rate measures showed that fast, stimulative music inhibited the return of heart rate toward resting levels (ηp = 0.06). Similarly, salivary cortisol levels tended to be lower in response to slow, sedative music (ηp = 0.11). There was a main effect of condition for affective valence indicating that the slow, sedative condition elicited more positive affective responses compared with the control and fast, stimulative conditions (ηp = 0.12). The present findings support the notion that slow, sedative music can expedite the recovery process immediately after strenuous exercise.

  12. Political pugilists: recuperative gender strategies in canadian electoral politics.

    Science.gov (United States)

    Maiolino, Elise

    2015-05-01

    This paper offers the concept recuperative gender strategies to describe how political leaders work to restore their public gender identities. The author examines a charity-boxing match between two Canadian politicians, Justin Trudeau and Patrick Brazeau. Trudeau is the current leader of the Liberal Party of Canada and son of former Prime Minister, Pierre Trudeau. Brazeau was a Conservative Senator. Through a discourse analysis of 222 national newspaper articles published on the match, this paper chronicles Justin Trudeau's transition from "precariously masculine" to "sufficiently masculine" and discusses the significance of this transformation for Trudeau's suitability for Liberal Party leadership. Cet article propose le concept de stratégies de récupération des sexes pour décrire et expliquer comment des dirigeants politiques travaillent à rétablir leurs identités sexuelles publiques. J'analyse la couverture médiatique du combat de boxe caritatif datant de mars 2012 et opposant deux politiciens canadiens : Justin Trudeau, le chef du Parti libéral du Canada, et Patrick Brazeau, un sénateur conservateur. En m'appuyant sur une analyse de discours de 222 articles de journaux nationaux publiés au sujet de ce combat, je détaille la transition de Justin Trudeau d'une forme de masculinité « précaire » à une « masculinité suffisante », et je discute de l'importance de cette transformation pour l'aptitude perçue de Trudeau comme chef du Parti libéral. © 2015 Canadian Sociological Association/La Société canadienne de sociologie.

  13. Successful Management of Refractory Type 1 Renal Tubular Acidosis with Amiloride

    Directory of Open Access Journals (Sweden)

    Patrick Oguejiofor

    2017-01-01

    Full Text Available A 28-year-old female with history of hypothyroidism, Sjögren’s Syndrome, and Systemic Lupus Erythematosus (SLE presented with complaints of severe generalized weakness, muscle pain, nausea, vomiting, and anorexia. Physical examination was unremarkable. Laboratory test showed hypokalemia at 1.6 mmol/l, nonanion metabolic acidosis with HCO3 of 11 mmol/l, random urine pH of 7.0, and urine anion gap of 8 mmol/l. CT scan of the abdomen revealed bilateral nephrocalcinosis. A diagnosis of type 1 RTA likely secondary to Sjögren’s Syndrome was made. She was started on citric acid potassium citrate with escalating dosages to a maximum dose of 60 mEq daily and potassium chloride over 5 years without significant improvement in serum K+ and HCO3 levels. She had multiple emergency room visits for persistent muscle pain, generalized weakness, and cardiac arrhythmias. Citric acid potassium citrate was then replaced with sodium bicarbonate at 15.5 mEq every 6 hours which was continued for 2 years without significant improvement in her symptoms and electrolytes. Amiloride 5 mg daily was added to her regimen as a potassium sparing treatment with dramatic improvement in her symptoms and electrolyte levels (as shown in the figures. Amiloride was increased to 10 mg daily and potassium supplementation was discontinued without affecting her electrolytes. Her sodium bicarbonate was weaned to 7.7 mEq daily.

  14. The Kenny syndrome, a rare type of growth deficiency with tubular stenosis, transient hypoparathyroidism and anomalies of refraction.

    Science.gov (United States)

    Majewski, F; Rosendahl, W; Ranke, M; Nolte, K

    1981-03-01

    One family (3 cases) with the Kenny syndrome and a second family (3 cases) with features of Kenny syndrome but lacking medullary stenosis are reported. The main symptoms in both families are proportionate dwarfism, cortical thickening of tubular bones, variable anomalies of the calvaria, anemia, transient hypoparathyroidism and variable ocular anomalies. The latter include microphthalmia, and moderate-to-severe myopia or hyperopia. In the first family there was medullary stenosis of most tubular bones. In the second family two cases exhibited mild-to-moderate cortical thickening of tubular bones, but absent or mild medullary stenosis. Possible variability of the Kenny syndrome is discussed. Endocrine studies failed to demonstrate any permanent disturbance of parathormone or calcitonin metabolism, or GH deficiency. Pathogenesis remains unclear. Autosomal dominant inheritance seems to be likely.

  15. Analysis of the behavior of tubular-type equipment for nuclear waste treatment: sensitivities of the parameters affecting mass transfer yield

    International Nuclear Information System (INIS)

    Yoo, Jae Hyung; Lee, Byung Jik; Shim, Joon Bo; Kim, Eung Ho

    2007-01-01

    It was intended in this study to investigate the effects of various parameters on the chemical reaction or mass transfer yield in a tubular-type nuclear waste treatment equipment. Since such equipment. as a tubular reactor, multistage solvent extractor, and adsorption column, accompany chemical reaction or mass transfer along the fluid-flowing direction, mathematical modeling for each equipment was carried out first. Then their behaviors of the chemical reaction or mass transfer were predicted through computer simulations. The inherent major parameters for each equipment were chosen and their sensitivities affecting the reaction or mass transfer yield were analyzed. For the tubular reactor, the effects of axial diffusion coefficient and reaction rate constant on the reaction yield were investigated. As for the multistage solvent extractor, the back mixing of continuous phase and the distribution coefficient between fluid and solvent were considered as the major parameters affecting the extraction yield as well as concentration profiles throughout the axial direction of the extractor. For the adsorption column, the equilibrium constant between fluid and adsorbent surface. and the overall mass transfer coefficient between the two phases were taken as the major factors that affect the adsorption rate

  16. Tubular nanostructured materials for bioapplications

    Science.gov (United States)

    Xie, Jining; Chen, Linfeng; Srivatsan, Malathi; Varadan, Vijay K.

    2009-03-01

    Tubular nanomaterials possess hollow structures as well as high aspect ratios. In addition to their unique physical and chemical properties induced by their nanoscale dimensions, their inner voids and outer surfaces make them ideal candidates for a number of biomedical applications. In this work, three types of tubular nanomaterials including carbon nanotubes, hematite nanotubes, and maghemite nanotubes, were synthesized by different chemical techniques. Their structural and crystalline properties were characterized. For potential bioapplications of tubular nanomaterials, experimental investigations were carried out to demonstrate the feasibility of using carbon nanotubes, hematite nanotubes, and maghemite nanotubes in glucose sensing, neuronal growth, and drug delivery, respectively. Preliminary results show the promise of tubular nanomaterials in future biomedical applications.

  17. New form of China aster (Callistephus chinensis (L. Nees. Structure and biology of ray florets with open tubular corollas (type RO

    Directory of Open Access Journals (Sweden)

    Alicja Wosińska

    2013-12-01

    Full Text Available A radiomutant of China aster with a new type of head and new type of ray florets was described. All florets in the head were bisexual and tubular although dimorphic - they varied in size and colour. The place of ray florets in the head was taken by bisexual open tubular florets which were often crowned with irregular teeth. Disc florets were short and parchment-like. In both types of florets the following were compared: number and size of stamens, vitality of pollen and floret fertility. A number of teeth (lobes in the corolIas of disc florets was also determined. Attention was also paid to the frequently observed anomalies and in particular to stamen displation. The problem is discussed of whether the obtained form resulted from mutation of disc florets with the simultaneous mutation of factors determining the so far unknown in China aster the head type without the whorl ofray florets or whether it was a mutation of ray flowers (corolla type and androecium formation. The author presents the opinion that the form resulted from the mutation ligulate of ray florets to the type of florets described above.

  18. The study on nondestructive evaluation for a tubular structure by the lamb-type guided wave wedge

    International Nuclear Information System (INIS)

    Cho, Yun Ho; Park, Jung Chul

    1998-01-01

    The study on the cylindrical guided wave was carried out to investigate its feasibility for nondestructive evaluation of tubular structures such as heat exchanger tubings of power industries and various pipings of chemical plants. The concept of wedge design and incident angle selection to optimize guided wave generation is presented based on the dispersion theory and the snell's law for the cylindrical guided wave. The brass tubes with artificial defects in the circumferential or axial direction were used for detect defection experiments. It was found that guided wave sensitivity for detecting an axial defect can be remarkably improved by using non-axisymmetrically launched guided waves. Through this study, it is expected that the guided wave can be successfully applied to tubular structure inspections as an more advanced and efficient NDE technique than a conventional point-by-point technique.

  19. Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening.

    Science.gov (United States)

    Yang, Shufan; Phan, Hop V; Bustamante, Heriberto; Guo, Wenshan; Ngo, Hao H; Nghiem, Long D

    2017-06-01

    Recuperative thickening can intensify anaerobic digestion to produce more biogas and potentially reduce biosolids odour. This study elucidates the effects of sludge shearing during the thickening process on the microbial community structure and its effect on biogas production. Medium shearing resulted in approximately 15% increase in biogas production. By contrast, excessive or high shearing led to a marked decrease in biogas production, possibly due to sludge disintegration and cell lysis. Microbial analysis using 16S rRNA gene amplicon sequencing showed that medium shearing increased the evenness and diversity of the microbial community in the anaerobic digester, which is consistent with the observed improved biogas production. By contrast, microbial diversity decreased under either excessive shearing or high shearing condition. In good agreement with the observed decrease in biogas production, the abundance of Bacteroidales and Syntrophobaterales (which are responsible for hydrolysis and acetogenesis) decreased due to high shearing during recuperative thickening. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  20. CFD and FEM thermo-mechanical design of a recuperative-dissipative heat exchanger for a laboratory water gas shift reactor

    Energy Technology Data Exchange (ETDEWEB)

    Michele Vascellari; Stefano Sollai; Pier Francesco Orru; Giorgio Cau [University of Cagliari, Cagliari (Italy). Department of Mechanical Engineering

    2007-07-01

    A small scale test rig based on a two-stage reactor for testing water gas shift conversion processes has been set up at the Department of Mechanical Engineering at the University of Cagliari, chiefly for the purpose of supporting a pilot plant operation for high sulphur (Sulcis) coal gasification, gas cleaning and treatment, CO{sub 2} separation, hydrogen and electricity production. The laboratory test rig comprises two packed-bed reactors in series to be operated at different temperatures and has been designed for testing CO-shift conversion processes using a variety of catalysts for different syngas temperatures (up to 500{sup o}C) and compositions. One critical component of the system is a recuperative-dissipative heat exchanger placed between the two reactors. The heat exchanger, which preheats the syngas prior to entering the high temperature reactor and cools the shifted gas exiting there from, prior to its entering the low temperature reactor, is subjected to severe thermo-mechanical stress. Thus the design and analysis of this component, described herein, is a critical issue. A full 3D conjugate heat transfer CFD analysis of the tubular heat exchanger has been performed, considering different geometries. Based on the CFD results we were able to verify the preliminary design of the component, carried out using simple thermal correlations and to predict wall temperature distribution for the thermo-structural analysis. 10 refs., 10 figs., 2 tabs.

  1. Recuperative aluminium recycling plant. A demonstration at J. McIntyre (Aluminium) Ltd. [Nottingham (GB)

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    Direct energy savings worth up to 470,000 pounds/year are being achieved by J McIntyre (Aluminium) Ltd in the United Kingdom as a result of the development of a recuperative aluminium recycling plant. The overall design incorporates a novel version of a closed-well furnace coupled with a radically improved design of dry hearth furnace. The plant not only treats clean scrap more efficiently than at present, but will also treat contaminated scrap which has not previously been recycled in an environmentally acceptable way. This is because the plant incorporates fume pyrolysis, afterburning of organics, recuperation and fume treatment. At 1987 prices the total installed plant cost was 1.3M.pounds. The direct energy saving at 1987 fuel prices was between 294,000 and 470,000pounds/year. Also, the improved melting technique has reduced metal lost as dross by 2 - 8% (420 -1,680 tonnes/year) when compared to other furnace operations. The improved metal recovery (1987 prices) was worth a further 400,000 pounds - 1,600,000 pounds. Taking median figures for the total fuel-plus-metal savings results in a payback on the project of only 14 months, some six months less than anticipated. Other consequential benefits which have also helped in reducing operating costs have been improvements in output per man, reductions in sickness and absenteeism, and reduced down-time for maintenance and repair. (author).

  2. Factors influencing pollutant gas emissions of VOC recuperative incinerators-Large-scale parametric study

    International Nuclear Information System (INIS)

    Salvador, S.; Commandre, J.-M.; Kara, Y.

    2006-01-01

    This work establishes quantitative links between the operation parameters-plus one geometrical parameter-and the gas pollutant emissions of a recuperative incinerator (RI) of volatile organic compounds (VOCs). Using experimental design methodology, and based on a large number of experiments carried out on a half-industrial-scale pilot unit, mathematical expressions are established to calculate each of the pollutant emissions from the value of all the operation and design parameters. The gas emissions concerned are total hydrocarbons, and CO and NO x emissions, while the control parameters are the flow rate of the treated air flow, the concentration of VOCs in the air flow, the preheating temperature of the flow, and the temperature at the exit of the combustion chamber. One design parameter-the aperture of the diaphragms-is also considered. We show that the constraining emissions are only that of CO and NO x . Polynomials to predict them with a high accuracy are established. The air preheating temperature has an effect on the natural gas consumption, but not on CO and NO x emissions. There is an optimal value for the aperture of the diaphragms, and this value is quantitatively established. If the concentration of VOCs in the air flow is high, CO and NO x emissions both decrease and a high rate of efficiency in VOC destruction is attained. This demonstrates that a pre-concentration of VOCs in the air flow prior to treatment by RI is recommended. (author)

  3. Tubular closure device

    International Nuclear Information System (INIS)

    Klahn, F.C.; Nolan, J.H.; Wills, C.

    1982-01-01

    This invention relates to a closure mechanism for closing openings such as the bore of a conduit and for releasably securing members within the bore. More particularly, this invention relates to a closure mechanism for tubular irradiation surveillance specimen assembly holders used in nuclear reactors

  4. Tubular membrane bioreactors for biotechnological processes.

    Science.gov (United States)

    Wolff, Christoph; Beutel, Sascha; Scheper, Thomas

    2013-02-01

    This article is an overview of bioreactors using tubular membranes such as hollow fibers or ceramic capillaries for cultivation processes. This diverse group of bioreactor is described here in regard to the membrane materials used, operational modes, and configurations. The typical advantages of this kind of system such as environments with low shear stress together with high cell densities and also disadvantages like poor oxygen supply are summed up. As the usage of tubular membrane bioreactors is not restricted to a certain organism, a brief overview of various applications covering nearly all types of cells from prokaryotic to eukaryotic cells is also given here.

  5. Tubular closure mechanism

    International Nuclear Information System (INIS)

    Kalen, D.D.; Mitchem, J.W.

    1982-01-01

    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

  6. Dual-objective optimization of organic Rankine cycle (ORC) systems using genetic algorithm: a comparison between basic and recuperative cycles

    Science.gov (United States)

    Hayat, Nasir; Ameen, Muhammad Tahir; Tariq, Muhammad Kashif; Shah, Syed Nadeem Abbas; Naveed, Ahmad

    2017-08-01

    Exploitation of low potential waste thermal energy for useful net power output can be done by manipulating organic Rankine cycle systems. In the current article dual-objectives (η_{th} and SIC) optimization of ORC systems [basic organic Rankine cycle (BORC) and recuperative organic Rankine cycle (RORC)] has been done using non-dominated sorting genetic algorithm (II). Seven organic compounds (R-123, R-1234ze, R-152a, R-21, R-236ea, R-245ca and R-601) have been employed in basic cycle and four dry compounds (R-123, R-236ea, R-245ca and R-601) have been employed in recuperative cycle to investigate the behaviour of two systems and compare their performance. Sensitivity analyses show that recuperation boosts the thermodynamic behaviour of systems but it also raises specific investment cost significantly. R-21, R-245ca and R-601 show attractive performance in BORC whereas R-601 and R-236ea in RORC. RORC, due to higher total investment cost and operation & maintenance costs, has longer payback periods as compared to BORC.

  7. Tubular closure mechanism

    International Nuclear Information System (INIS)

    Kalen, D.D.; Mitchem, J.W.

    1981-01-01

    An apparatus is provided for closing the bore of a tube and releasably securing articles within the tube under longitudinal load. A latching member has a cylindrical section and several circumferentially-spaced elongated latches hanging down from one end of the cylinder. An elongated actuator has integral cam and spline and is partly located within the latch with the cam radially contacting the latches and the spline projecting into the circumferential spaces between the latches. The actuator is axially movable between a position in which the latches are locked to the tube walls and a position in which the latches are secured from contact with the tube walls. Means are provided for axially moving the actuator such that the cam positions the latches; and means are also provided for engaging the articles within the tube. The closure is particularly applicable to tubular irradiation surveillance specimen assembly holders used in reactors

  8. Efecto citotóxico de la toxina shiga tipo 2 y su subunidad b en células epiteliales tubulares renales humanas en cultivo Cytotoxic effect of Shiga toxin type 2 and its B subunit on human renal tubular epithelial cell cultures

    Directory of Open Access Journals (Sweden)

    Virginia Pistone Creydt

    2005-04-01

    Full Text Available Escherichia coli enterohemorrágica productora de toxina Shiga (Stx causa diarrea acuosa, colitis hemorrágica y síndrome urémico hemolítico (SUH. En Argentina, el SUH es la principal causa de insuficiencia renal en niños. El objetivo de este trabajo fue estudiar la toxicidad de Stx tipo 2 (Stx2 y su subunidad B (Stx2B en células epiteliales tubulares renales humanas (CERH, en presencia y ausencia de factores inflamatorios. Los efectos citotóxicos se evaluaron como alteración de la funcionalidad del epitelio; daños histológicos; viabilidad celular; síntesis de proteínas y apoptosis celular. Los resultados muestran que Stx2 regula el pasaje de agua a través de CERH a tiempos menores de 1h de incubación. A tiempos mayores, hasta 72 hs, el estudio de la morfología, la viabilidad, la síntesis de proteínas y la apoptosis demostró que las CERH fueron sensibles a la acción citotóxica de Stx2 y Stx2B de una manera dosis y tiempo dependiente. Estos efectos fueron potenciados por lipopolisacáridos bacterianos (LPS, IL-1b, y butirato.Shiga toxin (Stx-producing E.coli causing watery diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome (HUS. In Argentina, HUS is the most common cause of acute renal failure in children. The purpose of the present study was to examine the cytotoxicity of Stx type 2 (Stx2 and its B subunit (Stx2B on human renal tubular epithelial cells (HRTEC, in the presence and absence of inflammatory factors. Cytotoxic effects were assessed in terms of functionality of the epithelium, histological damage, cell viability, protein synthesis and cellular apoptosis. Results show that Stx2 regulates the passage of water through the HRTEC within an incubation period of 1h. Within longer periods, up to 72 hours, the study of morphology, viability, protein synthesis and apoptosis shows that HRTEC were sensitive to the cytotoxic action of Stx2 and Stx2B in a dose- and time-dependent manner. These effects were potentiated by

  9. Tubular bioreactor and its application; Tubular bioreactor to sono tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Endo, I.; Nagamune, T. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yuki, K. [Nikka Whisky Distilling Co. Ltd. Tokyo (Japan); Inaba, H. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1994-09-05

    The loop type tubular bioreactor (TBR) was developed where biocatalysts are trapped in the reactor by membrane module. A UF membrane or MF membrane and crossflow filtration were adopted for the membrane module, and the reactor loop was composed of four membrane modules. The reactor was operated at 2-4 m/s in membrane surface velocity and 300-400 kPa in filtration pressure. As the result of the high-density culture of lactic acid bacteria and yeast, a biomass concentration was more than 10 times that in batch culture, suggesting the remarkable enhancement of a production efficiency. As the result of the continuous fermentation of cider, the fast fermentation more than 60 times that in conventional ones was obtained together with the same quality as conventional ones. Such a fast fermentation was probably achieved by yeast suspended in the fermenter of TBR, by yeast hardly affected physico-chemically as compared with immobilized reactors, and by small effect of mass transfer on reaction systems. 4 refs., 6 figs.

  10. Fractal solutions of recirculation tubular chemical reactors

    International Nuclear Information System (INIS)

    Berezowski, Marek

    2003-01-01

    Three kinds of fractal solutions of model of recirculation non-adiabatic tubular chemical reactors are presented. The first kind concerns the structure of Feigenbaum's diagram on the limit of chaos. The second kind and the third one concern the effect of initial conditions on the dynamic solutions of models. In the course of computations two types of recirculation were considered, viz. the recirculation of mass (return of a part of products' stream) and recirculation of heat (heat exchange in the external heat exchanger)

  11. Renal Tubular Acidosis

    Science.gov (United States)

    ... is called transport. One researcher has theorized that Charles Dickens may have been describing a child with ... urine and the potassium level in the blood will help identify which type of RTA a person ...

  12. HER-2 amplification in tubular carcinoma of the breast.

    Science.gov (United States)

    Oakley, Gerard J; Tubbs, Raymond R; Crowe, Joseph; Sebek, Bruce; Budd, G Thomas; Patrick, Rebecca J; Procop, Gary W

    2006-07-01

    The prognostic and therapeutic implications of HER-2 gene amplification and estrogen and progesterone receptor status in breast cancer are well described. To address the relative paucity of information concerning HER-2 amplification for tubular carcinomas, we assessed the frequency of gene amplification in 55 tubular carcinomas of the breast from 54 patients, 5 of which had axillary node metastases. The HER-2 gene copy number was assessed by fluorescence in situ hybridization for the majority of tumors analyzed, whereas estrogen and progesterone receptor status was achieved by immunohistochemical analysis. HER-2 gene amplification was not observed in any of the tumors examined, and most were estrogen receptor-positive. This HER-2 gene amplification frequency was significantly lower than the frequency of gene amplification previously reported for all invasive ductal carcinoma of no special type (P < .01). HER-2 gene amplification likely occurs infrequently, or not at all, in tubular carcinomas of the breast, whereas most express estrogen receptors.

  13. Torsional stresses in the transverse fillet weld tubular joints

    NARCIS (Netherlands)

    Gunay, D.; Aydemir, A.; Özer, H.

    1996-01-01

    Torsional stresses, 'tre and tel , in tbe transverse fillet tubular weld joint subjected to torsional load have been analyzed by the finite element method using triangular and quadrilateral izoparametric axisymmetric fourier type torus finite elements. There is an axisymmetry with respect to

  14. Development and demonstration of a gas-fired recuperative confined radiant burner (deliverable 42/43). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    The objective of the project was to develop and demonstrate an innovative, efficient, low-pollutant, recuperative gas-fired IR-system (infrared radiation) for industrial processes (hereafter referred to as the CONRAD-system). The CONRAD-system is confined, so flue gases from the combustion can be kept separated from the product. The gas/air mixture to the burner is preheated by means of the flue gas, which increases the radiant efficiency of the CONRAD-system significantly over traditional gas-fired IR burners. During the first phase of the project, the CONRAD-system was designed and developed. The conducted work included a survey on suitable burner materials, modelling of the burner system, basic design of burner construction, control etc., experimental characterisation of several preprototypes and detailed design of the internal heat exchanger in the burner. The result is a cost effective burner system with a documented radiant efficiency up to 66% and low emissions (NO{sub x} and CO) all in accordance with the criteria of success set up at the start of the project. In the second phase of the project, the burner system was established and tested in laboratory and in four selected industrial applications: 1) Drying of coatings on sand cores in the automotive industry. 2) Baking of bread/cake. 3) General purpose painting/powder curing process 4. Curing of powder paint on wood components. The results from the preliminary tests Overe used to optimise the CONRAD-system, before it was applied in the industrial processes and demonstrated. However, the optimised burners manufactured for demonstration suffered from different 'infant failures', which made the installation in an industrial environment very cumbersome, and even impossible in the food industry and the automotive industry. In the latter cases realistic laboratory tests Overe carried out and the established know how reported for use when the burner problems are overcome.(au)

  15. ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Gorensek, M.; Edwards, T.

    2009-06-11

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  16. Lab-scale demonstration of recuperative thickening technology for enhanced biogas production and dewaterability in anaerobic digestion processes.

    Science.gov (United States)

    Cobbledick, Jeffrey; Aubry, Nicholas; Zhang, Victor; Rollings-Scattergood, Sasha; Latulippe, David R

    2016-05-15

    There is growing interest in the use of high performance anaerobic digestion (AD) processes for the production of biogas at wastewater treatment facilities to offset the energy demands associated with wastewater treatment. Recuperative thickening (RT) is a promising technique which involves recycling a portion of the digested solids back to the incoming feed. In general there exists a significant number of knowledge gaps in the field of RT because the studies that have been conducted to date have almost exclusively occurred in pilot plant or full scale trials; this approach greatly limits the amount of process optimization that can be done in a given trial. In this work, a detailed and comprehensive study of RT was conducted at the lab scale; two custom designed digesters (capacity = 1.5 L) were operated in parallel with one acting as a 'control' digester and the other operating under a semi-batch RT mode. There was no significant change in biogas methane composition for the two digesters, however the RT digester had an average biogas productivity over two times higher than the control one. It was found that the recycling of the polymer flocculant back into the RT digester resulted in a significant improvement in dewatering performance. At the highest polymer concentration tested, the capillary suction time (CST) values for flocculated samples for the RT digester were over 6 times lower than the corresponding values for the control digester. Thus, there exists an opportunity to decrease the overall consumption of polymer flocculants through judicious selection of the dose of polymer flocculant that is used both for the thickening and end-stage dewatering steps in RT processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Recuperative dual fuel bruner with low NO{sub x} emissions

    Energy Technology Data Exchange (ETDEWEB)

    Munko, A.; Kleine Jaeger, F.; Koehne, H. [RWTH Aachen (Germany). Energie- und Stofftransport

    2003-07-01

    In a current research project of the Arbeitsgemeinschaft Industrieller Forschungsvereinigungen e.V. (AIF) (a German research association) a new dual fuel burner for radiant tubes is being developed at the Department tof Heat and Mass Transfer (EST, RWTH Aachen University). As combustible gas (natural gas type H / Erdgas H) and fuel oil (Heizoel Extra Leicht) are used. These research activities represent the further development of the radiant tube oil burner that was developed on behalf of the AIF and in cooperation with the Forschungsgemeinschaft Industrieofenbau (FOGI e.V.) (AIF project 12345B). The radiant tube burner was designed for the furnace temperature 1000 C can the firing rate 20 to 40 kW. Due to the vaporization of the fuel oil and the homogeneous fuel mixing with a flue gas flow, at the furnace temperature 1000 C and preheated air temperature 850 C NO{sub x}-emissions below 200 mg/m{sup 3} (5% O{sub 2}, Heizoel Extra Leicht) are reached. Using gas (natural gas type H) the burner tests indicate a high NO{sub x}-reduction potential - in gas operation at a lab furnace (furnace temperature 700 C) NO{sub x}-emissions below 40 mg/m{sup 3} result. The future works within the project are the construction of a dual-fuel mixing-device for the alternative use of liquid and gaseous fuel as well as further burner operation tests at furnace temperature 1000 C. (orig.)

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

    International Nuclear Information System (INIS)

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

    1987-01-01

    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 ≅ 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 0 C or in medium containing 5 μM colchicine or nocodazole at 37 0 C leads to disassembly of microtubules and fragmentation of the tubular lysosomes. Return of the cultures to 37 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

  19. Development and field-scale optimization of a honeycomb zeolite rotor concentrator/recuperative oxidizer for the abatement of volatile organic carbons from semiconductor industry.

    Science.gov (United States)

    Yang, Ji; Chen, Yufeng; Cao, Limei; Guo, Yuling; Jia, Jinping

    2012-01-03

    The combined concentrator/oxidizer system has been proposed as an effective physical-chemical option and proven to be a viable solution that enables Volatile Organic Carbons (VOCs) emitters to comply with the regulations. In this work, a field scale honeycomb zeolite rotor concentrator combined with a recuperative oxidizer was developed and applied for the treatment of the VOC waste gas. The research shows the following: (1) for the adsorption rotor, zeolite is a more appropriate material than Granular Activated Carbon (GAC). The designing and operation parameters of the concentrator were discussed in detail including the size and the optimal rotation speed of rotor. Also the developed rotor performance's was evaluated in the field; (2) Direct Fired Thermal Oxidizer (DFTO), Recuperative Oxidizer (RO), Regenerative Thermal Oxidizer (RTO) and Regenerative Catalytic oxidizer (RCO) are the available incinerators and the RO was selected as the oxidizer in this work; (3) The overall performance of the developed rotor/oxidizer was explored in a field scale under varying conditions; (4) The energy saving strategy was fulfilled by reducing heat loss from the oxidizer and recovering heat from the exhaust gas. Data shows that the developed rotor/oxidizer could remove over 95% VOCs with reasonable cost and this could be helpful for similar plants when considering VOC abatement.

  20. Numerical investigation of transient behaviour of the recuperative heat exchanger in a MR J-T cryocooler using different heat transfer correlations

    Science.gov (United States)

    Damle, R. M.; Ardhapurkar, P. M.; Atrey, M. D.

    2016-12-01

    In J-T cryocoolers operating with mixed refrigerants (nitrogen-hydrocarbons), the recuperative heat exchange takes place under two-phase conditions. Simultaneous boiling of the low pressure stream and condensation of the high pressure stream results in higher heat transfer coefficients. The mixture composition, operating conditions and the heat exchanger design are crucial for obtaining the required cryogenic temperature. In this work, a one-dimensional transient algorithm is developed for the simulation of the two-phase heat transfer in the recuperative heat exchanger of a mixed refrigerant J-T cryocooler. Modified correlation is used for flow boiling of the high pressure fluid while different condensation correlations are employed with and without the correction for the low pressure fluid. Simulations are carried out for different mixture compositions and numerical predictions are compared with the experimental data. The overall heat transfer is predicted reasonably well and the qualitative trends of the temperature profiles are also captured by the developed numerical model.

  1. Modified tubularized incised plate urethroplasty

    Directory of Open Access Journals (Sweden)

    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.

  2. New methods for the geometrical analysis of tubular organs.

    Science.gov (United States)

    Grélard, Florent; Baldacci, Fabien; Vialard, Anne; Domenger, Jean-Philippe

    2017-12-01

    This paper presents new methods to study the shape of tubular organs. Determining precise cross-sections is of major importance to perform geometrical measurements, such as diameter, wall-thickness estimation or area measurement. Our first contribution is a robust method to estimate orthogonal planes based on the Voronoi Covariance Measure. Our method is not relying on a curve-skeleton computation beforehand. This means our orthogonal plane estimator can be used either on the skeleton or on the volume. Another important step towards tubular organ characterization is achieved through curve-skeletonization, as skeletons allow to compare two tubular organs, and to perform virtual endoscopy. Our second contribution is dedicated to correcting common defects of the skeleton by new pruning and recentering methods. Finally, we propose a new method for curve-skeleton extraction. Various results are shown on different types of segmented tubular organs, such as neurons, airway-tree and blood vessels. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Urinary Markers of Tubular Injury in Early Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    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.

  4. Tubular lining material for pipelines having bends

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Tubular inverse opal scaffolds for biomimetic vessels

    Science.gov (United States)

    Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

    2016-07-01

    There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

  6. 78 FR 14361 - U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United...

    Science.gov (United States)

    2013-03-05

    ... Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United States Steel Corporation, Mckeesport, PA; Notice of Initiation of Investigation To Terminate Certification of Eligibility Pursuant to... Tubular Products, McKeesport Tubular Operations Division, Subsidiary of United States Steel Corporation...

  7. CT diagnosis of intramedulear lesions of the tubular bone

    International Nuclear Information System (INIS)

    Wagner-Manslau, C.; Feuerbach, S.; Biehl, T.

    1985-01-01

    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) [de

  8. Design and performance of tubular flat-plate solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Flow analysis of tubular fuel assembly using CFD code

    International Nuclear Information System (INIS)

    Park, J. H.; Park, C.; Chae, H. T.

    2004-01-01

    Based on the experiences of HANARO, a new research reactor is under conceptual design preparing for future needs of research reactor. Considering various aspects such as nuclear physics, thermal-hydraulics, mechanical structure and the applicability of HANARO technology, a tubular type fuel has been considered as that of a new research reactor. Tubular type fuel has several circular fuel layers, and each layer consists of 3 curved fuel plates arranged with constant small gap to build up cooling channels. In the thermal-hydraulic point, it is very important to maintain each channel flow velocity be equal as much as possible, because the small gaps between curved thin fuel plates independently forms separate coolant channels, which may cause a thermal-hydraulic problem in certain conditions. In this study, commercial CFD(Computational Fluid Dynamics) code, Fluent, has been used to investigate flow characteristics of tubular type fuel assembly. According to the computation results for the preliminary conceptual design, there is a serious lack of uniformity of average velocity on the each coolant channel. Some changes for initial conceptual design were done to improve the balance of velocity distribution, and analysis was done again, too. The results for the revised design showed that the uniformity of each channel velocity was improved significantly. The influence of outermost channel gap width on the velocity distribution was also examined

  10. High-fidelity stack and system modeling for tubular solid oxide fuel cell system design and thermal management

    Science.gov (United States)

    Kattke, K. J.; Braun, R. J.; Colclasure, A. M.; Goldin, G.

    Effective thermal integration of system components is critical to the performance of small-scale (design and simulation tool for a highly-integrated tubular SOFC system. The SOFC is modeled using a high fidelity, one-dimensional tube model coupled to a three-dimensional computational fluid dynamics (CFD) model. Recuperative heat exchange between SOFC tail-gas and inlet cathode air and reformer air/fuel preheat processes are captured within the CFD model. Quasi one-dimensional thermal resistance models of the tail-gas combustor (TGC) and catalytic partial oxidation (CPOx) complete the balance of plant (BoP) and SOFC coupling. The simulation tool is demonstrated on a prototype 66-tube SOFC system with 650 W of nominal gross power. Stack cooling predominately occurs at the external surface of the tubes where radiation accounts for 66-92% of heat transfer. A strong relationship develops between the power output of a tube and its view factor to the relatively cold cylinder wall surrounding the bundle. The bundle geometry yields seven view factor groupings which correspond to seven power groupings with tube powers ranging from 7.6-10.8 W. Furthermore, the low effectiveness of the co-flow recuperator contributes to lower tube powers at the bundle outer periphery.

  11. Thermochemical recuperative combined cycle with methane-steam reforming combustion; Tennengasu kaishitsu nensho ni yoru konbaindo saikuru hatsuden no kokoritsuka oyobi denryoku fuka heijunka taio

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, R.; Essaki, K.; Tsutsumi, A. [The University of Tokyo, Tokyo (Japan). Dept. of Chemical System Engineering; Kaganoi, S.; Kurimura, H. [Teikoku Sekiyu Co., Tokyo (Japan); Sasaki, T.; Ogawa, T. [Toshiba Co., Tokyo (Japan)

    2000-03-10

    Thermochemical recuperative combined cycles with methane-steam reforming are proposed for improving their thermal efficiency and for peak-load leveling. For targeting higher thermal efficiency, a cycle with methane-steam reforming reaction heated by gas turbine exhaust was analyzed. The inlet temperature of gas turbine was set at 1,350 degree C. Low-pressure steam extracted from a steam turbine is mixed with methane, and then this mixture is heated by part of the gas turbine exhaust to promote a reforming reaction. The rest of the exhaust heat is used to produce steam, which drives steam turbines to generate electricity. The effect of steam-to-methane ratio (S/C) on thermal efficiency of the cycle, as well as on methane conversion, is investigated by using the ASPEN Plus process simulator. The methane feed rate was fixed at constant and S/C ratio was varied from 2.25 to 4.75. Methane conversion shows an increasing trend toward the ratio and has a maximum value of 17.9 % at S/C=4.0. Thermal efficiency for the system is about 51 % higher than that calculated for a conventional 1,300 degree C class combined cycle under similar conditions. A thermochemical recuperative combined cycle is designed for peak-load leveling. In night-time operation from 20 : 00 to 8 : 00 it stores hydrogen produced by methane steam reforming at S/C=3.9 to save power generation. The gas turbine inlet temperature is 1,330 degree C. In daytime operation from 8 : 00 to 20 : 00 the chemically recuperated combined cycle operated at S/C=2.0 is driven by the mixture of a combined cycle operated at constant load with the same methane feed rate, whereas daytime operation generated power 1.26 times larger than that of the combined cycle. (author)

  12. Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.

    Directory of Open Access Journals (Sweden)

    Ana Tobar

    Full Text Available BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03. Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001, a 94% higher Bowman's space volume (P=0.003, a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02 and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01. The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity

  13. Testing of tubular goods - a critical review of past and actual testing procedures

    Energy Technology Data Exchange (ETDEWEB)

    Teodoriu, C. [Texas A and M Univ., Houston, TX (United States); Holzmann, J.; Klaws, M. [TU Clausthal (Germany). Inst. fuer Erdoel- und Erdgastechnik

    2007-09-13

    Testing of oil country tubular goods (OCTG) is based on standards and offers the user a comparison platform between products of different manufacturers. But, do the standard based testing procedures assume the real loads on OCTG? More likely, the existing standards or recommendations on tubular testing have been evolving together with the new demands on OCTG loading. Since nowadays the oil and gas industry is looking to develop extreme reservoir types (deep water, HP/HT), there is a need of a better understanding and continuous improvement of testing procedures. The following poster proposes an analysis of existing procedures to test tubular goods and then will focus on the future demands on OCTG testing. New loads, as casing fatigue, will be discussed and analyzed based on the authors experience gained during more than 8 years of testing tubular goods at the Clausthal University of Technology, Institute of Petroleum Engineering. (orig.)

  14. Iatrogenic Digital Compromise with Tubular Dressings

    Directory of Open Access Journals (Sweden)

    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.

  15. Renal Tubular Function in Systemic Lupus Erythematosus*

    African Journals Online (AJOL)

    immune' diseases such as. Sjogren's syndrome,'" systemic lupus erythematosus. (SLE),3 alveolitis' and chronic active hepatitis.' The reported abnormalities of renal tubular function include impairment of acid excretion and urinary concentration.

  16. A neglected case of Renal Tubular Acidosis

    International Nuclear Information System (INIS)

    Derakhshan, A.; Basiratnia, M.; Fallahzadeh, M.H.; Al-Hashemi, G.H.

    2007-01-01

    In this report, we present a case of a child with distal renal tubular acidosis, severe failure to thrive and profound rickets, who was only 7.8 Kg when presented at 6 years of age. His response to treatment and his follow up for four years is discussed. Although failure to thrive is a common finding in renal tubular acidosis but the physical and x-ray findings in our case were unique. (author)

  17. A tubular electrode for radiofrequency ablation therapy

    KAUST Repository

    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.

  18. A Role for Tubular Necroptosis in Cisplatin-Induced AKI

    Science.gov (United States)

    Xu, Yanfang; Ma, Huabin; Shao, Jing; Wu, Jianfeng; Zhou, Linying; Zhang, Zhirong; Wang, Yuze; Huang, Zhe; Ren, Junming; Liu, Suhuan; Chen, Xiangmei

    2015-01-01

    Cell death and inflammation in the proximal tubules are the hallmarks of cisplatin-induced AKI, but the mechanisms underlying these effects have not been fully elucidated. Here, we investigated whether necroptosis, a type of programmed necrosis, has a role in cisplatin-induced AKI. We found that inhibition of any of the core components of the necroptotic pathway—receptor-interacting protein 1 (RIP1), RIP3, or mixed lineage kinase domain-like protein (MLKL)—by gene knockout or a chemical inhibitor diminished cisplatin-induced proximal tubule damage in mice. Similar results were obtained in cultured proximal tubular cells. Furthermore, necroptosis of cultured cells could be induced by cisplatin or by a combination of cytokines (TNF-α, TNF-related weak inducer of apoptosis, and IFN-γ) that were upregulated in proximal tubules of cisplatin-treated mice. However, cisplatin induced an increase in RIP1 and RIP3 expression in cultured tubular cells in the absence of cytokine release. Correspondingly, overexpression of RIP1 or RIP3 enhanced cisplatin-induced necroptosis in vitro. Notably, inflammatory cytokine upregulation in cisplatin-treated mice was partially diminished in RIP3- or MLKL-deficient mice, suggesting a positive feedback loop involving these genes and inflammatory cytokines that promotes necroptosis progression. Thus, our data demonstrate that necroptosis is a major mechanism of proximal tubular cell death in cisplatin-induced nephrotoxic AKI. PMID:25788533

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

    Directory of Open Access Journals (Sweden)

    P Ravi

    2013-01-01

    Full Text Available 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.

  20. Thermal CFD Analysis of Tubular Light Guides

    Directory of Open Access Journals (Sweden)

    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.

  1. Transition piece for joining together tubular pieces

    International Nuclear Information System (INIS)

    Holko, K.H.

    1981-01-01

    A transition piece for joining together tubular pieces formed respectively from a low alloy or carbon steel and a high temperature alloy containing at least 16% chromium includes a plurality of tubular parts welded together and formed from materials of selected composition with a maximum chromium content difference of 5% between adjacent parts when the chromium content of each part is below 10% and a maximum chromium difference of 7% between adjacent parts when the chromium content of either part is above 10%. The transition parts are also graded as to such characteristics as thermal expansion coefficient. The transition parts at opposite ends of the transition joint have chromium percentages similar to the tubular pieces to which they are to be joined. The parts may be joined by fusion and/or friction welding and parts may be formed by fusion weld deposition. (author)

  2. Tubular overexpression of gremlin induces renal damage susceptibility in mice.

    Directory of Open Access Journals (Sweden)

    Alejandra Droguett

    Full Text Available A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular and interstitial fibrosis are hallmarks of renal progression. However, fibrosis of the kidney remains an unresolved challenge, and its molecular mechanisms are still not fully understood. Gremlin is an embryogenic gene that has been shown to play a key role in nephrogenesis, and its expression is generally low in the normal adult kidney. However, gremlin expression is elevated in many human renal diseases, including diabetic nephropathy, pauci-immune glomerulonephritis and chronic allograft nephropathy. Several studies have proposed that gremlin may be involved in renal damage by acting as a downstream mediator of TGF-β. To examine the in vivo role of gremlin in kidney pathophysiology, we generated seven viable transgenic mouse lines expressing human gremlin (GREM1 specifically in renal proximal tubular epithelial cells under the control of an androgen-regulated promoter. These lines demonstrated 1.2- to 200-fold increased GREM1 expression. GREM1 transgenic mice presented a normal phenotype and were without proteinuria and renal function involvement. In response to the acute renal damage cause by folic acid nephrotoxicity, tubule-specific GREM1 transgenic mice developed increased proteinuria after 7 and 14 days compared with wild-type treated mice. At 14 days tubular lesions, such as dilatation, epithelium flattening and hyaline casts, with interstitial cell infiltration and mild fibrosis were significantly more prominent in transgenic mice than wild-type mice. Tubular GREM1 overexpression was correlated with the renal upregulation of profibrotic factors, such as TGF-β and αSMA, and with increased numbers of monocytes/macrophages and lymphocytes compared to wild-type mice. Taken together, our results suggest that GREM1-overexpressing mice have an increased susceptibility to renal damage, supporting the involvement of gremlin in renal damage

  3. Ranitidine has no influence on tubular creatinine secretion

    NARCIS (Netherlands)

    van den Berg, J. G.; Koopman, M. G.; Arisz, L.

    1996-01-01

    Oral cimetidine competitively inhibits tubular secretion of creatinine. We investigated the potential of oral ranitidine, a comparable H2-receptor antagonist, to block tubular creatinine secretion. In 10 healthy subjects, clearances of inulin and endogenous creatinine were simultaneously measured

  4. Drill pipes and casings utilizing multi-conduit tubulars

    Energy Technology Data Exchange (ETDEWEB)

    Curlett, H.B.

    1989-01-24

    A seal adapted for use with a multi-conduit well tubular, or the like, is described which consists of: a plate with fluid passages, each passage corresponding to an opening of a conduit of the multiconduit tubular, and a groove on the plate around each passage; and elastomer means partially embeddable into each groove for sealing each conduit of a tubular to a corresponding conduit of another similar tubular.

  5. Development of Partial Tubular Flat Knitting Fabric Composite Preform

    Directory of Open Access Journals (Sweden)

    Jiang Wei Qing

    2016-01-01

    Full Text Available After building some structures of partial tubular flat knitting fabric composite preform, the influencing factor on tubular section was analyzed and the fabric was knitted selectively. The partial tubular flat knitting fabric composite preform were Knitted by changing different yarn, row number and two-sided partial tubular flat knitting fabric. Multilayer sheet would be got after hot pressing and it has big market prospects and good application value.

  6. Tubular permanent magnet actuators: cogging forces characterization

    NARCIS (Netherlands)

    Paulides, J.J.H.; Janssen, J.L.G.; Encica, L.; Lomonova, E.A.

    2009-01-01

    Tubular permanent magnet actuators are evermore used in demanding industrial and automotive applications. However, these actuators can suffer from large cogging forces, which have a destabilizing effect on the servo control system and compromise position and speed control accuracy. This paper

  7. Work tool in a tubular element

    International Nuclear Information System (INIS)

    Griffaton, J.

    1991-01-01

    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 [fr

  8. Boron--epoxy tubular structure members

    Science.gov (United States)

    Shakespeare, W. B. J.; Nelson, P. T.; Lindkvist, E. C.

    1973-01-01

    Composite materials fabricate thin-walled tubular members which have same load-carrying capabilities as aluminum, titanium, or other metals, but are lighter. Interface between stepped end fitting and tube lends itself to attachments by primary as well as secondary bonding. Interlaminar shear and hoop stress buildup in attachment at end fitting is avoided.

  9. Pointlike Inclusion Interactions in Tubular Membranes

    NARCIS (Netherlands)

    Vahid Belarghou, A.; Idema, T.

    2016-01-01

    Membrane tubes and tubular networks are ubiquitous in living cells. Inclusions like proteins are vital for both the stability and the dynamics of such networks. These inclusions interact via the curvature deformations they impose on the membrane. We analytically study the resulting membrane

  10. Reliability Analysis of Tubular Joints in Offshore Structures

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Sørensen, John Dalsgaard

    1987-01-01

    Reliability analysis of single tubular joints and offshore platforms with tubular joints is" presented. The failure modes considered are yielding, punching, buckling and fatigue failure. Element reliability as well as systems reliability approaches are used and illustrated by several examples....... Finally, optimal design of tubular.joints with reliability constraints is discussed and illustrated by an example....

  11. Diffraction patterns from 7-Angstroms tubular halloysite

    International Nuclear Information System (INIS)

    Eggleton, T.

    1998-01-01

    Full text: The diffraction patterns from 7-Angstroms tubular halloysite are superficially like those from kaolinite. Diffraction from a tubular aggregate of atoms, however, differs from that from a crystal because there is no linear repetition in two of the three conventional crystallographic directions. In tubular halloysite, the tube axis is [010] or [110] and in this direction the unit cell repeats in the normal linear fashion. The x-axis, by contrast, changes direction tangentially around the tube circumference, and there can be no true z-axis, because unit cells in the radial direction do not superimpose, since each successive tubular layer has a larger radius than its predecessor and therefore must contain more unit cells than its predecessor. Because tubular 'crystals' do not have a lattice repeat, use of Bragg 'hkl' indices is not appropriate. In the xy plane, a small area of the structure approximates a flat layer silicate, and hk indices may been used to label diffraction maxima. Similarly, successive 1:1 layers tangential to the tube walls yield a series of apparent 001 diffraction maxima. Measurement of these shows that the d-spacings do not form an exact integral series. The reason for this lies in the curvature of the structure. Calculated electron and powder X-ray diffraction patterns, based on a model of concentric 1:1 layers with no regular relation between them other than the 7.2 Angstroms spacing, closely simulate the observed data. Evidence for the 2-layer structure that is generally accepted may need to be reassessed in the light of these results

  12. Separation of BSA through FAU-type zeolite ceramic composite membrane formed on tubular ceramic support: Optimization of process parameters by hybrid response surface methodology and biobjective genetic algorithm.

    Science.gov (United States)

    Vinoth Kumar, R; Ganesh Moorthy, I; Pugazhenthi, G

    2017-08-09

    In this study, Faujasite (FAU) zeolite was coated on low-cost tubular ceramic support as a separating layer through hydrothermal route. The mixture of silicate and aluminate solutions was used to create a zeolitic separation layer on the support. The prepared zeolite ceramic composite membrane was characterized using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), particle size distribution (PSD), field emission scanning electron microscopy (FESEM), and zeta potential measurements. The porosity of ceramic support (53%) was reduced by the deposition of FAU (43%) zeolite layer. The pore size and water permeability of the membrane were evaluated as 0.179 µm and 1.62 × 10 -7  m 3 /m 2  s kPa, respectively, which are lower than that of the support (pore size of 0.309 µm and water permeability of 5.93 × 10 -7  m 3 /m 2  s kPa). The permeate flux and rejection potential of the prepared membrane were evaluated by microfiltration of bovine serum albumin (BSA). To study the influences of three independent variables such as operating pressure (68.94-275.79 kPa), concentration of BSA (100-500 ppm), and solution pH (2-4) on permeate flux and percentage of rejection, the response surface methodology (RSM) was used. The predicted models for permeate flux and rejection were further subjected to biobjective genetic algorithm (GA). The hybrid RSM-GA approach resulted in a maximum permeate flux of 2.66 × 10 -5  m 3 /m 2  s and BSA rejection of 88.02%, at which the optimum conditions were attained as 100 ppm BSA concentration, 2 pH solution, and 275.79 kPa applied pressure. In addition, the separation efficiency was compared with other membranes applied for BSA separation to know the potential of the fabricated FAU zeolite ceramic composite membrane.

  13. 78 FR 37584 - U.S. Steel Tubular Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United...

    Science.gov (United States)

    2013-06-21

    ... make the following certification: All workers of U.S. Steel Tubular Products, McKeesport Tubular... Products, Inc., Mckeesport Tubular Operations Division, Subsidiary of United States Steel Corporation, Mckeesport, Pennsylvania; Notice of Amended Certification Pursuant to Section 221 of the Trade Act of 1974...

  14. ANALYSIS OF ELASTIC DEFORMATION OF BRAIDED TUBULAR STRUCTURES FOR MEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Mehmet Emin YÜKSEKKAYA

    2001-02-01

    Full Text Available In this study, self-expanding stents were fabricated and analyzed. These stents are in the form of 3-D tubular braided structures made of polymeric materials. This type of structures is used in medicine to open clogged artheries and veins by exerting radial force. The amount of radial force exerted into the membrane should not give any damage to the veins. Therefore, the geometry of the three dimensional tubular braided fabric is analyzed to give an optimum radial force for medical applications.

  15. Investigation and Calculation of Magnetic Field in Tubular Linear Reluctance Motor Using FEM

    Directory of Open Access Journals (Sweden)

    MOSALLANEJAD, A.

    2010-11-01

    Full Text Available In this paper the magnetic flux density of tubular linear reluctance motor (TLRM in open type magnetic circuit is studied. Also, all magnetic flux density calculation methods in winding of tubular linear reluctance motor are described. The effect of structure parameters on magnetic flux density is also discussed. Electromagnetic finite-element analysis is used for simulation of magnetic field, and simulation results of the magnetic field analysis with DC voltage excitation are compared with results obtained from calculation methods. The comparison yields a good agreement.

  16. SOFC mini-tubulares basadas en YSZ

    Directory of Open Access Journals (Sweden)

    Campana, R.

    2008-08-01

    Full Text Available Tubular SOFC have the advantage over planar SOFC of the low temperature sealing and more resistance to thermal shock. On the other hand the volumetric power density of tubular Fuel Cells goes with the inverse of the tube diameter which added to the faster warm-up kinetics makes low diameter tubular SOFC favorable for low power applications. Anode supported tubular SOFC of 3mm diameter and 150 mm length with YSZ electrolyte were fabricated and tested by V-I measurements using H2-Ar (5, 10, 100 vol% as fuel and air for the cathode. The NiO-YSZ tubes of about 400 μm thickness were produced by hydrostatic pressure and then coated with an YSZ film of 15-20 μm. The electrolyte was deposited using a manual aerograph. After sintering either Pt paste or LSF (with YSZ or SDC coatings of about 20-50 μm thickness were deposited for the cathode. The OCV of the cells were excellent, very close to the expected Nernst law prediction indicating that there were not gas leaks. The maximun electrical power of the cell was near to 500mW/cm2 at 850ºC operation temperature. Complex impedance measurements of the cells were performed in order to determine the resistance of the different cell components.

    La principal ventaja de las SOFC tubulares frente a las planares es el sellado de la cámara anódica y catódica a bajas temperaturas. Además la densidad de energía volumétrica de las pilas tubulares es inversamente proporcional al diámetro del tubo, que añadido a los tiempos cortos de encendido y apagado hacen que las mini-tubulares sean interesantes para usos de baja potencia. Se han fabricado y caracterizado SOFC tubulares soportadas en ánodo de 3mm de diámetro y de 150 mm de longitud, 400μm de espesor, con electrolito de YSZ depositado por spray de 15-20 μm. Los tubos de NiO-YSZ son producidos por prensado isostático. La caracterización eléctrica se ha realizado empleando H2-Ar como combustible an

  17. Field portable low temperature porous layer open tubular cryoadsorption headspace sampling and analysis part I: Instrumentation.

    Science.gov (United States)

    Bruno, Thomas J

    2016-01-15

    Building on the successful application in the laboratory of PLOT-cryoadsorption as a means of collecting vapor (or headspace) samples for chromatographic analysis, in this paper a field portable apparatus is introduced. This device fits inside of a briefcase (aluminum tool carrier), and can be easily transported by vehicle or by air. The portable apparatus functions entirely on compressed air, making it suitable for use in locations lacking electrical power, and for use in flammable and explosive environments. The apparatus consists of four aspects: a field capable PLOT-capillary platform, the supporting equipment platform, the service interface between the PLOT-capillary and the supporting equipment, and the necessary peripherals. Vapor sampling can be done with either a hand piece (containing the PLOT capillary) or with a custom fabricated standoff module. Both the hand piece and the standoff module can be heated and cooled to facilitate vapor collection and subsequent vapor sample removal. The service interface between the support platform and the sampling units makes use of a unique counter current approach that minimizes loss of cooling and heating due to heat transfer with the surroundings (recuperative thermostatting). Several types of PLOT-capillary elements and sampling probes are described in this report. Applications to a variety of samples relevant to forensic and environmental analysis are discussed in a companion paper. Published by Elsevier B.V.

  18. Distal renal tubular acidosis and hepatic lipidosis in a cat.

    Science.gov (United States)

    Brown, S A; Spyridakis, L K; Crowell, W A

    1986-11-15

    Clinical and laboratory evidence of hepatic failure was found in a chronically anorectic cat. Simultaneous blood and urine pH determinations established a diagnosis of distal renal tubular acidosis. The cat did not respond to treatment. Necropsy revealed distal tubular nephrosis and hepatic lipidosis. The finding of distal renal tubular acidosis in a cat with hepatic lipidosis emphasizes the importance of complete evaluation of acid-base disorders in patients.

  19. CD47 regulates renal tubular epithelial cell self-renewal and proliferation following renal ischemia reperfusion.

    Science.gov (United States)

    Rogers, Natasha M; Zhang, Zheng J; Wang, Jiao-Jing; Thomson, Angus W; Isenberg, Jeffrey S

    2016-08-01

    Defects in renal tubular epithelial cell repair contribute to renal ischemia reperfusion injury, cause acute kidney damage, and promote chronic renal disease. The matricellular protein thrombospondin-1 and its receptor CD47 are involved in experimental renal ischemia reperfusion injury, although the role of this interaction in renal recovery is unknown. We found upregulation of self-renewal genes (transcription factors Oct4, Sox2, Klf4 and cMyc) in the kidney of CD47(-/-) mice after ischemia reperfusion injury. Wild-type animals had minimal self-renewal gene expression, both before and after injury. Suggestive of cell autonomy, CD47(-/-) renal tubular epithelial cells were found to increase expression of the self-renewal genes. This correlated with enhanced proliferative capacity compared with cells from wild-type mice. Exogenous thrombospondin-1 inhibited self-renewal gene expression in renal tubular epithelial cells from wild-type but not CD47(-/-) mice, and this was associated with decreased proliferation. Treatment of renal tubular epithelial cells with a CD47 blocking antibody or CD47-targeting small interfering RNA increased expression of some self-renewal transcription factors and promoted cell proliferation. In a syngeneic kidney transplant model, treatment with a CD47 blocking antibody increased self-renewal transcription factor expression, decreased tissue damage, and improved renal function compared with that in control mice. Thus, thrombospondin-1 via CD47 inhibits renal tubular epithelial cell recovery after ischemia reperfusion injury through inhibition of proliferation/self-renewal. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  20. The problem of the recuperative capacity of mammals after acute sublethal whole-body exposure to high-energy radiation, with special regard to the juvenile organism

    International Nuclear Information System (INIS)

    Baumann, B.

    1978-01-01

    After a single acute whole-body irradiation with 200 kV x-rays (1.5 mm Cu, dose rate 45 min -1 ), radiosensitivitis (LD 50/30d) have been determined in 9 age groups of lactating mice and compared with those of adult mice. In split-dose experiments (Dc = 300 R) recovery rates after 1, 2, 3, 5, 10, and 100 days of recovery have been determined in animals 1, 6, 12, 16, and 80 days old; further examinations have been carried out after 3 days of recovery in 6 day-old animals. The findings are compared with earlier investigations in the same strain of animals and with literature on comparable investigations in mice and other mammals. During infancy, there is a slight, age-dependent increase in radiation resistance after a single exposure, and adult mice are about 10% more radiosensitive than juveniles. The recovery rate of lactating mice increases until 2 hours after irradiation, as in adult animals. In contrast to the values measured in adults, however, the recovery rate of animals 1 and 6 days old then drops to values of -27% resp. -63% of Dc = 300 R after 1 resp. 3 days: Sensitization. In animals 12 and 16 days old, too there is a decrease in recovery after 2 hours, but no marked sensitization. In all animals pre-irradiated in infancy, the recovery rate after 10 days is not higher than 45%, and even after 100 days there is a clear residual damage. In animals 6 days old, which are particularly radiosensitive, the highest sensitization was found 3 days after a pre-irradiation dose of 150 to 200 R, and a saturation of the sensitization mechanism was derived for higher doses. Biological causes of sensitization are still unknown. According to the author's literature studies, other species of mammals, too do not always follow the assumptions on the recuperative capacity of mammal organisms which have been derived from studies in adult mice. (orig.) [de

  1. Thermal characteristics of tubular receivers of solar radiation line concentrators

    International Nuclear Information System (INIS)

    Klychev, Sh.I.; Zakhidov, R.A.; Khuzhanov, R. et al.

    2013-01-01

    A stationary thermal model of an LCS-HR system is considered, taking into account the basic parameters of the problem: availability of a transparent screen, selectivity of the receiver, characteristics of the heat carrier and average concentration on the surface of the tubular receiver C"". Based on this model, an algorithm and program of numerical research of the thermal characteristics of the HR-temperature of heating and local and average coefficients of efficiency are developed. For possible concentrations, the selectivity of the receiver and the transparency of the screen in linear concentrators, the potential stationary heating temperatures, and the coefficients of efficiency for main three types of heat carriers - air, water, and liquid metal coolant are studied. The time of achieving stationary values by the temperatures of the heat carrier is estimated. (author)

  2. TUBULAR DISORDERS WITH RICKETS-LIKE SYNDROME

    Directory of Open Access Journals (Sweden)

    N.N. Kartamysheva

    2011-01-01

    Full Text Available Often under the guise of «ordinary» Rickets are more severe kidney diseases, developing as a result of inherited or acquired, primary or secondary defects in the renal tubules. Incorrect diagnosis leads to an inadequate therapy, rapid progression of disease and renal failure. The article describes the main approaches to the diagnosis and treatment of disorders of tubular rachitis similar syndrome, presents a number of clinical cases in author's practice.Key words: tubulopathy, acidosis, electrolyte disorders, rickets, rickets-like syndrome, diagnostics, treatment, children.

  3. Tubular solid oxide fuel cell development program

    Energy Technology Data Exchange (ETDEWEB)

    Ray, E.R.; Cracraft, C.

    1995-12-31

    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.

  4. Tubular fluoropolymer arrays with high piezoelectric response

    Science.gov (United States)

    Zhukov, Sergey; Eder-Goy, Dagmar; Biethan, Corinna; Fedosov, Sergey; Xu, Bai-Xiang; von Seggern, Heinz

    2018-01-01

    Polymers with electrically charged internal air cavities called ferroelectrets exhibit a pronounced piezoelectric effect and are regarded as soft functional materials suitable for sensor and actuator applications. In this work, a simple method for fabricating piezoelectret arrays with open-tubular channels is introduced. A set of individual fluoroethylenepropylene (FEP) tubes is compressed between two heated metal plates. The squeezed FEP tubes are melted together at +270 °C. The resulting structure is a uniform, multi-tubular, flat array that reveals a strong piezoelectric response after a poling step. The fabricated arrays have a high ratio between piezoelectrically active and non-active areas. The optimal charging voltage and stability of the piezoelectric coefficients with pressures and frequency were experimentally investigated for two specific array structures with wall thickness of 50 and 120 μm. The array fabricated from 50 μm thick FEP tubes reveals a stable and high piezoelectric coefficient of {d}33 = 120-160 pC N-1 with a flat frequency response between 0.1 Hz and 10 kHz for pressures between 1 and 100 kPa. An increase of wall thickness to 120 μm is accompanied by a more than twofold decrease in the piezoelectric coefficient as a result of a simultaneously higher effective array stiffness and lower remanent polarization. The obtained experimental results can be used to optimize the array design with regard to the electromechanical performance.

  5. Recuperative supercritical carbon dioxide cycle

    Science.gov (United States)

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  6. Rectosigmoid tubular duplication presenting as perineal sepsis in a neonate.

    Science.gov (United States)

    Zhang, Zhibo; Huang, Ying; Wang, Dajia; Su, Pengjun

    2010-03-01

    Tubular rectal duplication is a very rare congenital anomaly. We report a case of tubular rectal duplication in a newborn baby who presented with perianal sepsis. The diagnosis was confirmed by barium enema, magnetic resonance imaging, and at operation. We performed total mucosectomy through a posterior sagittal incision combined with laparotomy. The patient was doing quite well at 17-month follow-up examination.

  7. Cyclosporine A induces senescence in renal tubular epithelial cells

    NARCIS (Netherlands)

    Jennings, Paul; Koppelstaetter, Christian; Aydin, Sonia; Abberger, Thomas; Wolf, Anna Maria; Mayer, Gert; Pfaller, Walter

    The nephrotoxic potential of the widely used immunosuppressive agent cyclosporine A (CsA) is well recognized. However, the mechanism of renal tubular toxicity is not yet fully elucidated. Chronic CsA nephropathy and renal organ aging share some clinical features, such as renal fibrosis and tubular

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

    DEFF Research Database (Denmark)

    Prætorius, Helle; Leipziger, Jens Georg

    2010-01-01

    -reaching advances indicate that ATP is often used as a local transmitter for classical sensory transduction. This transmission apparently also applies to sensory functions in the kidney. Locally released ATP is involved in sensing of renal tubular flow or in detecting the distal tubular load of NaCl at the macula...

  9. Multiple metabolic hits converge on CD36 as novel mediator of tubular epithelial apoptosis in diabetic nephropathy.

    Directory of Open Access Journals (Sweden)

    Katalin Susztak

    2005-02-01

    Full Text Available Diabetic nephropathy (DNP is a common complication of type 1 and type 2 diabetes mellitus and the most common cause of kidney failure. While DNP manifests with albuminuria and diabetic glomerulopathy, its progression correlates best with tubular epithelial degeneration (TED and interstitial fibrosis. However, mechanisms leading to TED in DNP remain poorly understood.We found that expression of scavenger receptor CD36 coincided with proximal tubular epithelial cell (PTEC apoptosis and TED specifically in human DNP. High glucose stimulated cell surface expression of CD36 in PTECs. CD36 expression was necessary and sufficient to mediate PTEC apoptosis induced by glycated albumins (AGE-BSA and CML-BSA and free fatty acid palmitate through sequential activation of src kinase, and proapoptotic p38 MAPK and caspase 3. In contrast, paucity of expression of CD36 in PTECs in diabetic mice with diabetic glomerulopathy was associated with normal tubular epithelium and the absence of tubular apoptosis. Mouse PTECs lacked CD36 and were resistant to AGE-BSA-induced apoptosis. Recombinant expression of CD36 in mouse PTECs conferred susceptibility to AGE-BSA-induced apoptosis.Our findings suggest a novel role for CD36 as an essential mediator of proximal tubular apoptosis in human DNP. Because CD36 expression was induced by glucose in PTECs, and because increased CD36 mediated AGE-BSA-, CML-BSA-, and palmitate-induced PTEC apoptosis, we propose a two-step metabolic hit model for TED, a hallmark of progression in DNP.

  10. Forming of Polymeric Tubular Micro-components

    DEFF Research Database (Denmark)

    Qin, Yi; Zhao, Jie; Anyasodor, Gerald

    2015-01-01

    platform for the production of functional polymeric tubular micro-components. The chapter gives background on the current market and process development trends, followed by description of materials, process configuration, tool design and machine development for each processing technology as well......This chapter is intended to provide an overview of three nontraditional shaping technologies for the forming of polymeric micro-tubes, which are hot embossing, blow molding, and cross rolling, as well as realization of a process chain and the integration of a modular machine-based manufacturing...... as strategy for integration of the technologies and equipment into a common platform. Finally, potential applications of the technologies and facilities developed are highlighted....

  11. Sunscope natural light systems : tubular skylights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This brochure described a tubular skylight designed by Sunscope Natural Light Systems. The Sunscope is a super-reflective light system in which daylight is reflected down a cylinder to a translucent ceiling fixture that diffuses natural light throughout the room in which it is placed. The Sunscope requires no structure changes, is installed in less than 3 hours, and requires no drywall repairs or repainting. The system eliminates the need for daytime electric lighting, and causes no winter heat losses or summer heat gains. Available in 3 sizes, the Sunscope has no moving parts and is fully maintenance-free. The system was designed for use in commercial and residential applications. 7 figs.

  12. Inherited renal tubular defects with hypokalemia

    Directory of Open Access Journals (Sweden)

    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.

  13. An ultrasonic inspection tool for production tubulars

    Energy Technology Data Exchange (ETDEWEB)

    Newton, K; Martin, R; Ravenscroft, F [AEA Technology, Harwell (United Kingdom)

    1994-06-01

    Advances in ultrasonic technology, high temperature techniques and remote processing power are enabling a new generation of inspection tools to be developed. This paper describes a particular new ultrasonic caliper system, developed by AEA Technology, with the aim of providing improved information about the condition of production tubulars of oil and gas wells. The system is designed to provide enhanced surface area coverage compared to the current devices, which are typically mechanical 'finger' calipers. It also provides a non-contacting measure of corrosion and wear together with direct on-line output and automated data analysis. The new tool is designed to operate in oil and gas, vertical or deviated wells and has the potential for modification to inspect small diameter pipes in topside or other plant. (author)

  14. Cytocompatibility of a silk fibroin tubular scaffold

    International Nuclear Information System (INIS)

    Wang, Jiannan; 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

  15. STUDY THE CREEP OF TUBULAR SHAPED FIBER REINFORCED COMPOSITES

    Directory of Open Access Journals (Sweden)

    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.

  16. Mucinous tubular and spindle cell carcinoma of kidney: A rare case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Geramizadeh Bita

    2009-10-01

    Full Text Available Low grade mucinous tubular and spindle cell carcinoma of kidney was newly established as a distinct renal cell carcinoma in the World Health Organization (WHO classification of 2004. Until now, less than 60 cases have been reported and the largest series represented approximately 15 patients with this type of tumor. Herein, we report a case of mucinous tubular and spindle cell carcinoma in a 63-year-old male presented with right flank pain which was diagnosed after nephrectomy. Pathologists should consider this diagnosis and its spectrum of histopathologic features in mind to ensure an accurate diagnosis.

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

    DEFF Research Database (Denmark)

    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......-reaching advances indicate that ATP is often used as a local transmitter for classical sensory transduction. This transmission apparently also applies to sensory functions in the kidney. Locally released ATP is involved in sensing of renal tubular flow or in detecting the distal tubular load of NaCl at the macula...

  18. Perfis tubulares : aspectos arquitetônicos e estruturais.

    OpenAIRE

    Gerken, Fernanda de Sousa

    2003-01-01

    Programa de Pós Graduação em Engenharia Civil. Departamento de Engenharia Civil, Escola de Minas, Universidade Federal de Ouro Preto. O presente trabalho tem como objetivo apresentar uma visão geral da utilização das estruturas tubulares no contexto da evolução das estruturas metálicas em geral, com destaque para o estudo de obras que mostram o estado da arte da construção tubular no Brasil. A utilização dos perfis tubulares estruturais é abordada tanto do ponto de vista da ...

  19. Performance evaluation of two solar stills of different geometries: Tubular versus triangular: Experimental study, numerical simulation, and second law analysis

    DEFF Research Database (Denmark)

    Rahbar, Nader; Asadi, Amin; Fotouhi-Bafghi, Ehsan

    2018-01-01

    In this study, two types of solar stills, triangular and tubular one, have been experimentally tested under a real weather condition. Following the same procedure, the experiments were carried out over seven typical winter days and the effects of solar radiation and ambient temperature on water...... are the main reasons to have a better water production in the tubular still. Furthermore, the cost of water production by the triangular solar still was found to be lower due to its lower manufacturing cost compare to that of tubular one. Based on the experimental results, two new correlations have been...... productivity and total efficiency of the stills has been experimentally investigated. Furthuremore, to understand the detail structures of the air flow inside the enclosures, the fluid flow has been numerically simulated using computational fluid dynamics. Having the details of the fluid flow, the values...

  20. Multi-Scaled Modeling the Mechanical Properties of Tubular Composites Reinforced with Innovated 3D Weft Knitted Spacer Fabrics

    Science.gov (United States)

    Omrani, Elahe; Hasani, Hossein; Dibajian, Sayed Houssain

    2018-02-01

    Textile composites of 3D integrated spacer configurations have been recently focused by several researchers all over the world. In the present study, newly-designed tubular composites reinforced with 3D spacer weft knitted fabrics were considered and the effects of their structural parameters on some applicable mechanical properties were investigated. For this purpose, two different samples of 3D spacer weft knitted textile types in tubular form were produced on an electronic flat knitting machine, using glass/nylon hybrid yarns. Thermoset tubular-shaped composite parts were manufactured via vacuum infusion molding process using epoxy resin. The mechanical properties of the produced knitted composites in term of external static and internal hydrostatic pressures were evaluated. Resistance of the produced composites against the external static and internal hydrostatic pressures was numerically simulated using multi-scale modeling method. The finding revealed that there is acceptable correlation between experimental and theoretical results.

  1. Diffuse Lymphomatous Infiltration of Kidney Presenting as Renal Tubular Acidosis and Hypokalemic Paralysis: Case Report

    Science.gov (United States)

    Jhamb, Rajat; Gupta, Naresh; Garg, Sandeep; Kumar, Sachin; Gulati, Sameer; Mishra, Deepak; Beniwal, Pankaj

    2007-01-01

    We report the case of a 22-year-old woman who presented with acute onset flaccid quadriparesis. Physical examination showed mild pallor with cervical and axillary lymphadenopathy, hepatomegaly, and bilateral smooth enlarged kidneys. Neurological examination revealed lower motor neuron muscle weakness in all the four limbs with hyporeflexia and normal sensory examination. Laboratory investigations showed anemia, severe hypokalemia, and metabolic acidosis. Urinalysis showed a specific gravity of 1.010, pH of 7.0, with a positive urine anion gap. Ultrasound revealed hepatosplenomegaly with bilateral enlarged smooth kidneys. Renal biopsy was consistent with the diagnosis of non-Hodgkin lymphoma (B cell type). Metabolic acidosis, alkaline urine, and severe hypokalemia due to excessive urinary loss in our patient were suggestive of distal renal tubular acidosis. Renal involvement in lymphoma is usually subclinical and clinically overt renal disease is rare. Diffuse lymphomatous infiltration of the kidneys may cause tubular dysfunction and present with hypokalemic paralysis. PMID:18074421

  2. Tubular bending and pull-out forces in high-curvature well bores

    International Nuclear Information System (INIS)

    Dareing, D.W.; Ahlers, C.A.

    1991-01-01

    This paper is concerned with drag forces developed on tubulars in high-curvature well bores typically found in drainhole and horizontal drilling. The dog-leg severity of these types of boreholes are considerably higher than those typically found in conventional directional drilling. The objective of the study was to determine the significance of bending stiffness on drag forces in the pull-out mode. The method of analysis treats the tubular as a multi-spanned curved beam under tension and solves for radial displacements, slope, shear and bending moment over each span. Calculations show that bending stiffness is a minor factor provided there are no locally severe dog legs superimposed in the high-curvature well bore

  3. Smart concrete slabs with embedded tubular PZT transducers for damage detection

    Science.gov (United States)

    Gao, Weihang; Huo, Linsheng; Li, Hongnan; Song, Gangbing

    2018-02-01

    The objective of this study is to develop a new concept and methodology of smart concrete slab (SCS) with embedded tubular lead zirconate titanate transducer array for image based damage detection. Stress waves, as the detecting signals, are generated by the embedded tubular piezoceramic transducers in the SCS. Tubular piezoceramic transducers are used due to their capacity of generating radially uniform stress waves in a two-dimensional concrete slab (such as bridge decks and walls), increasing the monitoring range. A circular type delay-and-sum (DAS) imaging algorithm is developed to image the active acoustic sources based on the direct response received by each sensor. After the scattering signals from the damage are obtained by subtracting the baseline response of the concrete structures from those of the defective ones, the elliptical type DAS imaging algorithm is employed to process the scattering signals and reconstruct the image of the damage. Finally, two experiments, including active acoustic source monitoring and damage imaging for concrete structures, are carried out to illustrate and demonstrate the effectiveness of the proposed method.

  4. Bi2212 HTS Tubular Bulk with Conical Shape for Current Lead

    International Nuclear Information System (INIS)

    Tamura, H; Mito, T; Yamada, Y; Watanabe, M; Ohkubo, J; Heller, R

    2006-01-01

    Current leads using HTS material have been developed for application in a large scale superconducting magnet system. Tokai University and NIFS have developed Bi2212 tubular bulk which was prepared by a diffusion process. 8 kA of maximum transport current was achieved by a tubular bulk with a cylindrical shape. The maximum current was estimated to be 2 kA at 50 K for this tubular bulk. A current lead can be designed with this bulk the warm end of the HTS part being at 50 K and the cold end at 4.2 K. Under this condition, the cross section of the cold end of the bulk can be reduced. This type of HTS bulk has a great potential for flexible design since the Bi2212 layer can be reacted on the surface of any shapes of substrate. If a conical shaped HTS bulk was made, it could be an advantage for heat leakage to the cold end. To confirm this effect, we have made two types of conical bulk. The transport current of the specimen exceeds 7 kA at 4.2 K and 4 kA of stable current flow was achieved with a warm end temperature of 50 K

  5. Scenario analysis of large scale algae production in tubular photobioreactors

    NARCIS (Netherlands)

    Slegers, P.M.; Beveren, van P.J.M.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    Microalgae productivity in tubular photobioreactors depends on algae species, location, tube diameter, biomass concentration, distance between tubes and for vertically stacked systems, the number of horizontal tubes per stack. A simulation model for horizontal and vertically stacked horizontal

  6. Hot Firing of a Full Scale Copper Tubular Combustion Chamber

    National Research Council Canada - National Science Library

    Cooley, C

    2002-01-01

    This paper describes the chamber design and hot firing test results for a full-scale copper tubular combustion chamber that has future application in a high-thrust, upper-stage expander cycle engine...

  7. Genetics Home Reference: renal tubular acidosis with deafness

    Science.gov (United States)

    ... adults with renal tubular acidosis with deafness have short stature, and many develop kidney stones. The metabolic acidosis ... enlarged vestibular aqueduct, can be seen with medical imaging. The vestibular aqueduct is a bony canal that ...

  8. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    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...

  9. Tubular forms of papova viruses in human laryngeal papilloma.

    Science.gov (United States)

    Arnold, W

    1979-01-01

    In two cases of recurrent laryngeal papillomatosis tubular forms of papova viruses could be observed. The same material revealed the close relation between nuclear chromatine and the release of particles, as well as a capsomere like substructure of the virions.

  10. Closure of tubular patent ductus arteriosus with the Amplatzer Vascular Plug IV: feasibility and safety.

    Science.gov (United States)

    Baruteau, Alban-Elouen; Lambert, Virginie; Riou, Jean-Yves; Angel, Claude-Yves; Belli, Emre; Petit, Jérôme

    2015-01-01

    Closure of tubular patent ductus arteriosus remains a challenging procedure. Anecdotal use of Amplatzer Vascular Plug IV for tubular ductus closure has been reported but feasibility and safety in a consecutive patients' series remain unknown. We performed a monocenter prospective study at the Marie Lannelongue Hospital in Paris, France. From 2009 to 2014, a total of 47 patients (39 infants, 3 children, and 5 adults) underwent ductus closure with the Plug IV. Ductus morphology was a type E in 34 (72.3%) patients and a type C in 13 (27.7%) patients. Ductus closure occurred in 39 (83.0%) infants at a median age of seven months (range: 3-23 months) and a median weight of 6.9 kg (range: 4.1-17.0 kg). A past history of prematurity and very low birth weight was found in 33 (70.2%) of them. Twelve (25.5%) patients had pulmonary hypertension. Mean Plug IV diameter was 1.9 ± 0.1 mm larger than the mean maximal ductus diameter. Early complete closure of the ductus was obtained in all patients. Early migration of an undersized Plug IV occurred in one (2.1%) patient and was suitable for percutaneous device retrieval. After a mean follow-up of 3.4 ± 1.4 years, all patients are alive and asymptomatic, no late complication occurred. Transcatheter closure of tubular ductus with the Amplatzer Vascular Plug IV can be safe and effective, with a 100% early occlusion rate. This device, suitable for a 4F sheath, is a new alternative for tubular ductus closure in low-body-weight infants. © The Author(s) 2014.

  11. The Fourier transform of tubular densities

    KAUST Repository

    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.

  12. The Fourier transform of tubular densities

    International Nuclear Information System (INIS)

    Prior, C B; Goriely, A

    2012-01-01

    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. (paper)

  13. Inflatable Tubular Structures Rigidized with Foams

    Science.gov (United States)

    Tinker, Michael L.; Schnell, Andrew R.

    2010-01-01

    Inflatable tubular structures that have annular cross sections rigidized with foams, and the means of erecting such structures in the field, are undergoing development. Although the development effort has focused on lightweight structural booms to be transported in compact form and deployed in outer space, the principles of design and fabrication are also potentially applicable to terrestrial structures, including components of ultralightweight aircraft, lightweight storage buildings and shelters, lightweight insulation, and sales displays. The use of foams to deploy and harden inflatable structures was first proposed as early as the 1960s, and has been investigated in recent years by NASA, the U.S. Air Force Research Laboratory, industry, and academia. In cases of deployable booms, most of the investigation in recent years has focused on solid cross sections, because they can be constructed relatively easily. However, solid-section foam-filled booms can be much too heavy for some applications. In contrast, booms with annular cross sections according to the present innovation can be tailored to obtain desired combinations of stiffness and weight through choice of diameters, wall thicknesses, and foam densities. By far the most compelling advantage afforded by this innovation is the possibility of drastically reducing weights while retaining or increasing the stiffnesses, relative to comparable booms that have solid foamfilled cross sections. A typical boom according to this innovation includes inner and outer polyimide film sleeves to contain foam that is injected between them during deployment.

  14. Tubular Initial Conditions and Ridge Formation

    Directory of Open Access Journals (Sweden)

    M. S. Borysova

    2013-01-01

    Full Text Available The 2D azimuth and rapidity structure of the two-particle correlations in relativistic A+A collisions is altered significantly by the presence of sharp inhomogeneities in superdense matter formed in such processes. The causality constraints enforce one to associate the long-range longitudinal correlations observed in a narrow angular interval, the so-called (soft ridge, with peculiarities of the initial conditions of collision process. This study's objective is to analyze whether multiform initial tubular structures, undergoing the subsequent hydrodynamic evolution and gradual decoupling, can form the soft ridges. Motivated by the flux-tube scenarios, the initial energy density distribution contains the different numbers of high density tube-like boost-invariant inclusions that form a bumpy structure in the transverse plane. The influence of various structures of such initial conditions in the most central A+A events on the collective evolution of matter, resulting spectra, angular particle correlations and vn-coefficients is studied in the framework of the hydrokinetic model (HKM.

  15. Hereditary Hypokalemic salt-losing tubular disorders

    International Nuclear Information System (INIS)

    Peters, M.; Konard, M.; Seyberth, H.W.

    2003-01-01

    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)

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

    Directory of Open Access Journals (Sweden)

    Ding F

    2014-09-01

    Full Text Available Fengan Ding,1 Yiping Li,1 Jing Liu,1 Lei Liu,1 Wenmin Yu,1 Zhi Wang,1 Haifeng Ni,2 Bicheng Liu,2 Pingsheng Chen1,2 1School of Medicine, Southeast University, Nanjing, People’s Republic of China; 2Institute of Nephrology, The Affiliated Zhongda Hospital, Southeast University, Nanjing, People’s Republic of China Background: Gold nanoparticles (GNPs can potentially be used in biomedical fields ranging from therapeutics to diagnostics, and their use will result in increased human exposure. Many studies have demonstrated that GNPs can be deposited in the kidneys, particularly in renal tubular epithelial cells. Chronic hypoxic is inevitable in chronic kidney diseases, and it results in renal tubular epithelial cells that are susceptible to different types of injuries. However, the understanding of the interactions between GNPs and hypoxic renal tubular epithelial cells is still rudimentary. In the present study, we characterized the cytotoxic effects of GNPs in hypoxic renal tubular epithelial cells.Results: Both 5 nm and 13 nm GNPs were synthesized and characterized using various biophysical methods, including transmission electron microscopy, dynamic light scattering, and ultraviolet–visible spectrophotometry. We detected the cytotoxicity of 5 and 13 nm GNPs (0, 1, 25, and 50 nM to human renal proximal tubular cells (HK-2 by Cell Counting Kit-8 assay and lactate dehydrogenase release assay, but we just found the toxic effect in the 5 nm GNP-treated cells at 50 nM dose under hypoxic condition. Furthermore, the transmission electron microscopy images revealed that GNPs were either localized in vesicles or free in the lysosomes in 5 nm GNPs-treated HK-2 cells, and the cellular uptake of the GNPs in the hypoxic cells was significantly higher than that in normoxic cells. In normoxic HK-2 cells, 5 nm GNPs (50 nM treatment could cause autophagy and cell survival. However, in hypoxic conditions, the GNP exposure at the same condition led to the

  17. Modeling constrained sintering of bi-layered tubular structures

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Kothanda Ramachandran, Dhavanesan; Ni, De Wei

    2015-01-01

    Constrained sintering of tubular bi-layered structures is being used in the development of various technologies. Densification mismatch between the layers making the tubular bi-layer can generate stresses, which may create processing defects. An analytical model is presented to describe the densi...... and thermo-mechanical analysis. Results from the analytical model are found to agree well with finite element simulations as well as measurements from sintering experiment....

  18. Electrolyte composition of renal tubular cells in gentamicin nephrotoxicity

    International Nuclear Information System (INIS)

    Matsuda, O.; Beck, F.X.; Doerge, A.T.; Thurau, K.

    1988-01-01

    The effect of long-term gentamicin administration on sodium, potassium, chloride and phosphorus concentrations was studied in individual rat renal tubular cells using electron microprobe analysis. Histological damage was apparent only in proximal tubular cells. The extent of damage was only mild after 7 days of gentamicin administration (60 mg/kg body wt/day) but much more pronounced after 10 days. GFR showed a progressive decline during gentamicin treatment. In non-necrotic proximal tubular cells, sodium was increased from 14.6 +/- 0.3 (mean +/- SEM) in controls to 20.6 +/- 0.4 after 7 and 22.0 +/- 0.8 mmol/kg wet wt after 10 days of gentamicin administration. Chloride concentration was higher only after 10 days (20.6 +/- 0.6 vs. 17.3 +/- 0.2 mmol/kg wet wt). Both cell potassium and phosphorus concentrations were diminished by 6 and 15, and by 8 and 25 mmol/kg wet wt after 7 and 10 days of treatment, respectively. In contrast, no major alterations in distal tubular cell electrolyte concentrations could be observed after either 7 or 10 days of gentamicin administration. As in proximal tubular cells, distal tubular cell phosphorus concentrations were, however, lowered by gentamicin treatment. These results clearly indicate that gentamicin exerts its main effect on proximal tubular cells. Decreased potassium and increased sodium and chloride concentrations were observed in proximal tubular cells exhibiting only mild histological damage prior to the onset of advanced tissue injury. Necrotic cells, on the other hand, showed widely variable intracellular electrolyte concentration patterns

  19. Luminal nucleotides are tonic inhibitors of renal tubular transport

    DEFF Research Database (Denmark)

    Leipziger, Jens Georg

    2011-01-01

    PURPOSE OF REVIEW: Extracellular ATP is an essential local signaling molecule in all organ systems. In the kidney, purinergic signaling is involved in an array of functions and this review highlights those of relevance for renal tubular transport. RECENT FINDINGS: Purinergic receptors are express...... discovered as an important signaling compartment in which local purinergic signaling determines an inhibitory tone for renal tubular transport. Blocking components of this system leads to tubular hyper-absorption, volume retention and elevated blood pressure.......PURPOSE OF REVIEW: Extracellular ATP is an essential local signaling molecule in all organ systems. In the kidney, purinergic signaling is involved in an array of functions and this review highlights those of relevance for renal tubular transport. RECENT FINDINGS: Purinergic receptors are expressed...... 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...

  20. Distal renal tubular acidosis in two children with acquired hypothyroidism.

    Science.gov (United States)

    Guerra-Hernández, Norma E; Ordaz-López, Karen V; Vargas-Poussou, Rosa; Escobar-Pérez, Laura; García-Nieto, Víctor M

    2018-04-28

    Two cases of children diagnosed with renal tubular acidosis (RTA) associated with autoimmune hypothyroidism are presented. Case 1 developed an intestinal ileus at the age of five in the context of a respiratory problem. The tests performed confirmed metabolic acidosis, hyperchloraemia, hypokalaemia and nephrocalcinosis. Case 2 was diagnosed with hypothyroidism at the age of 11, and with RTA two years later. In both patients, the diagnosis of RTA was verified when decreased maximum urinary pCO 2 was found. In case 2, a proximal bicarbonate leak (type 3 RTA) was also confirmed. This was the first case to be published on the topic. The causes of RTA in patients with hypothyroidism are reviewed. The deleterious effect on the kidneys may be due to the absence of thyroid hormone and/or autoantibodies in the cases of autoimmune hypothyroidism. Copyright © 2018 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  1. Oily bilge water treatment with a tubular ultrafiltration system

    Energy Technology Data Exchange (ETDEWEB)

    Harris, L.R.; Jackson, D.F.; Schatzberg, P.

    1976-11-01

    The Navy has been developing various oil pollution abatement systems. One potential process for the separation of oil in bilge water is ultrafiltration, a pressure-driven membrane process which can separate, concentrate, and fractionate macromolecular solutes and suspended species from water. A tubular ultrafiltration system using cellulosic and noncellulosic membranes was tested with bilge oil obtained from a patrol craft. Tests were also conducted with tap water, river water, a turbine lubricating oil, and a fuel oil, alone and in combination with a nonionic detergent. The addition of the detergent was observed to result in a steeper flux decline than when any of the fluids were evaluated alone. Both membrane types produced a permeate with an oil content generally less than 15 mg/l. Although the noncellulosic membranes exhibited higher flux rates than the cellulosic membranes, only the former could be restored by a cleaning operation to its initial water flux after experiencing a decline in flux. A cumulative irreversible flux decline was exhibited by the cellulosic membrane. Cleaning operations, some of which were time-consuming, consisted of flushing the membrane with ultrafiltrate, distilled water, tap water, or the manufacturer's enzyme-detergent formulation. Only the last of these, when employed at elevated temperature (125/sup 0/F), restored the initial water flux of the noncellulosic membrane.

  2. Oxidation-etching preparation of MnO2 tubular nanostructures for high-performance supercapacitors.

    Science.gov (United States)

    Zhu, Jixin; Shi, Wenhui; Xiao, Ni; Rui, Xianhong; Tan, Huiteng; Lu, Xuehong; Hng, Huey Hoon; Ma, Jan; Yan, Qingyu

    2012-05-01

    1D hierarchical tubular MnO(2) nanostructures have been prepared through a facile hydrothermal method using carbon nanofibres (CNFs) as sacrificial template. The morphology of MnO(2) nanostructures can be adjusted by changing the reaction time or annealing process. Polycrystalline MnO(2) nanotubes are formed with a short reaction time (e.g., 10 min) while hierarchical tubular MnO(2) nanostructures composed of assembled nanosheets are obtained at longer reaction times (>45 min). The polycrystalline MnO(2) nanotubes can be further converted to porous nanobelts and sponge-like nanowires by annealing in air. Among all the types of MnO(2) nanostructures prepared, tubular MnO(2) nanostructures composed of assembled nanosheets show optimized charge storage performance when tested as supercapacitor electrodes, for example, delivering an power density of 13.33 kW·kg(-1) and a energy density of 21.1 Wh·kg(-1) with a long cycling life over 3000 cycles, which is mainly related to their features of large specific surface area and optimized charge transfer pathway.

  3. Strain-Induced Rolled Thin Films for Lightweight Tubular Thermoelectric Generators

    KAUST Repository

    Singh, Devendra

    2017-11-24

    Thermoelectric generators (TEGs) are interesting energy harvesters of otherwise wasted heat. Here, a polymer-assisted generic process and its mechanics to obtain sputtered thermoelectric (TE) telluride material-based 3D tubular structures with unprecedented length (up to seamless 4 cm and further expandable) are shown. This length allows for large temperature differences between the hot and the cold ends, a critical but untapped enabler for high power generation. Compared with a flat slab, better area efficiency is observed for a rolled tube and compared with a solid rod architecture, a rolled tube uses less material (thus making it lightweight and cost effective) and has competitive performance advantage due to a smaller contact area. It is also shown that a tubular architecture thermopile-based TEG is able to generate up to 5 μW of power (eight pairs of p- and n-type thermopiles) through a temperature difference of 60 °C. The demonstrated process can play an important role in transforming 2D atomic crystal structure TE materials into 3D tubular thermopiles for effective TEG application, which can maintain higher temperature differences by longer distances between hot and cold ends.

  4. Ideal heat transfer conditions for tubular solar receivers with different design constraints

    Science.gov (United States)

    Kim, Jin-Soo; Potter, Daniel; Gardner, Wilson; Too, Yen Chean Soo; Padilla, Ricardo Vasquez

    2017-06-01

    The optimum heat transfer condition for a tubular type solar receiver was investigated for various receiver pipe size, heat transfer fluid, and design requirement and constraint(s). Heat transfer of a single plain receiver pipe exposed to concentrated solar energy was modelled along the flow path of the heat transfer fluid. Three different working fluids, molten salt, sodium, and supercritical carbon dioxide (sCO2) were considered in the case studies with different design conditions. The optimized ideal heat transfer condition was identified through fast iterative heat transfer calculations solving for all relevant radiation, conduction and convection heat transfers throughout the entire discretized tubular receiver. The ideal condition giving the best performance was obtained by finding the highest acceptable solar energy flux optimally distributed to meet different constraint(s), such as maximum allowable material temperature of receiver, maximum allowable film temperature of heat transfer fluid, and maximum allowable stress of receiver pipe material. The level of fluid side turbulence (represented by pressure drop in this study) was also optimized to give the highest net power production. As the outcome of the study gives information on the most ideal heat transfer condition, it can be used as a useful guideline for optimal design of a real receiver and solar field in a combined manner. The ideal heat transfer condition is especially important for high temperature tubular receivers (e.g. for supplying heat to high efficiency Brayton cycle turbines) where the system design and performance is tightly constrained by the receiver pipe material strength.

  5. Toxicogenomic multigene biomarker for predicting the future onset of proximal tubular injury in rats

    International Nuclear Information System (INIS)

    Minowa, Yohsuke; Kondo, Chiaki; Uehara, Takeki; Morikawa, Yuji; Okuno, Yasushi; Nakatsu, Noriyuki; Ono, Atsushi; Maruyama, Toshiyuki; Kato, Ikuo; Yamate, Jyoji; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro

    2012-01-01

    Drug-induced renal tubular injury is a major concern in the preclinical safety evaluation of drug candidates. Toxicogenomics is now a generally accepted tool for identifying chemicals with potential safety problems. The specific aim of the present study was to develop a model for use in predicting the future onset of drug-induced proximal tubular injury following repeated dosing with various nephrotoxicants. In total, 41 nephrotoxic and nonnephrotoxic compounds were used for the present analysis. Male Sprague-Dawley rats were dosed orally or intravenously once daily. Animals were exposed to three different doses (low, middle, and high) of each compound, and kidney tissue was collected at 3, 6, 9, and 24 h after single dosing, and on days 4, 8, 15, and 29 after repeated dosing. Gene expression profiles were generated from kidney total RNA using Affymetrix DNA microarrays. Filter-type gene selection and linear classification algorithms were employed to discriminate future onset of proximal tubular injury. We identified genomic biomarkers for use in future onset prediction using the gene expression profiles determined on day 1, when most of the nephrotoxicants had yet to produce detectable histopathological changes. The model was evaluated using a five-fold cross validation, and achieved a sensitivity of 93% and selectivity of 90% with 19 probes. We also found that the prediction accuracy of the optimized model was substantially higher than that produced by any of the single genomic biomarkers or histopathology. The genes included in our model were primarily involved in DNA replication, cell cycle control, apoptosis, and responses to oxidative stress and chemical stimuli. In summary, our toxicogenomic model is particularly useful for predicting the future onset of proximal tubular injury.

  6. Isolation and characterization of a primary proximal tubular epithelial cell model from human kidney by CD10/CD13 double labeling.

    Directory of Open Access Journals (Sweden)

    Cynthia Van der Hauwaert

    Full Text Available Renal proximal tubular epithelial cells play a central role in renal physiology and are among the cell types most sensitive to ischemia and xenobiotic nephrotoxicity. In order to investigate the molecular and cellular mechanisms underlying the pathophysiology of kidney injuries, a stable and well-characterized primary culture model of proximal tubular cells is required. An existing model of proximal tubular cells is hampered by the cellular heterogeneity of kidney; a method based on cell sorting for specific markers must therefore be developed. In this study, we present a primary culture model based on the mechanical and enzymatic dissociation of healthy tissue obtained from nephrectomy specimens. Renal epithelial cells were sorted using co-labeling for CD10 and CD13, two renal proximal tubular epithelial markers, by flow cytometry. Their purity, phenotypic stability and functional properties were evaluated over several passages. Our results demonstrate that CD10/CD13 double-positive cells constitute a pure, functional and stable proximal tubular epithelial cell population that displays proximal tubule markers and epithelial characteristics over the long term, whereas cells positive for either CD10 or CD13 alone appear to be heterogeneous. In conclusion, this study describes a method for establishing a robust renal proximal tubular epithelial cell model suitable for further experimentation.

  7. Augmenter of liver regeneration inhibits TGF-β1-induced renal tubular epithelial-to-mesenchymal transition via suppressing TβR II expression in vitro

    International Nuclear Information System (INIS)

    Liao, Xiao-hui; Zhang, Ling; Chen, Guo-tao; Yan, Ru-yu; Sun, Hang; Guo, Hui; Liu, Qi

    2014-01-01

    Tubular epithelial-to-mesenchymal transition (EMT) plays a crucial role in the progression of renal tubular interstitial fibrosis (TIF), which subsequently leads to chronic kidney disease (CKD) and eventually, end-stage renal disease (ESRD). We propose that augmenter of liver regeneration (ALR), a member of the newly discovered ALR/Erv1 protein family shown to ameliorate hepatic fibrosis, plays a similar protective role in renal tubular cells and has potential as a new treatment option for CKD. Here, we showed that recombinant human ALR (rhALR) inhibits EMT in renal tubular cells by antagonizing activation of the transforming growth factor-β1 (TGF-β1) signaling pathway. Further investigation revealed that rhALR suppresses the expression of TGF-β receptor type II (TβR II) and significantly alleviates TGF-β1-induced phosphorylation of Smad2 and nuclear factor-κB (NF-κB). No apparent adverse effects were observed upon the addition of rhALR alone to cells. These findings collectively suggest that ALR plays a role in inhibiting progression of renal tubular EMT, supporting its potential utility as an effective antifibrotic strategy to reverse TIF in CKD. - Highlights: • ALR is involved in the pathological progression of renal EMT in NRK-52E cells. • ALR suppresses the expression of TβRII and the phosphorylation of Smad2 and NF-κB. • ALR plays a role in inhibiting progression of renal tubular EMT

  8. Augmenter of liver regeneration inhibits TGF-β1-induced renal tubular epithelial-to-mesenchymal transition via suppressing TβR II expression in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xiao-hui [Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Zhang, Ling, E-mail: lindazhang8508@hotmail.com [Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Chen, Guo-tao; Yan, Ru-yu [Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Sun, Hang; Guo, Hui [Institute for Viral Hepatitis, Key Laboratory of Molecular Biology for Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China); Liu, Qi, E-mail: txzzliuqi@163.com [Institute for Viral Hepatitis, Key Laboratory of Molecular Biology for Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 (China)

    2014-10-01

    Tubular epithelial-to-mesenchymal transition (EMT) plays a crucial role in the progression of renal tubular interstitial fibrosis (TIF), which subsequently leads to chronic kidney disease (CKD) and eventually, end-stage renal disease (ESRD). We propose that augmenter of liver regeneration (ALR), a member of the newly discovered ALR/Erv1 protein family shown to ameliorate hepatic fibrosis, plays a similar protective role in renal tubular cells and has potential as a new treatment option for CKD. Here, we showed that recombinant human ALR (rhALR) inhibits EMT in renal tubular cells by antagonizing activation of the transforming growth factor-β1 (TGF-β1) signaling pathway. Further investigation revealed that rhALR suppresses the expression of TGF-β receptor type II (TβR II) and significantly alleviates TGF-β1-induced phosphorylation of Smad2 and nuclear factor-κB (NF-κB). No apparent adverse effects were observed upon the addition of rhALR alone to cells. These findings collectively suggest that ALR plays a role in inhibiting progression of renal tubular EMT, supporting its potential utility as an effective antifibrotic strategy to reverse TIF in CKD. - Highlights: • ALR is involved in the pathological progression of renal EMT in NRK-52E cells. • ALR suppresses the expression of TβRII and the phosphorylation of Smad2 and NF-κB. • ALR plays a role in inhibiting progression of renal tubular EMT.

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

    DEFF Research Database (Denmark)

    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......-strength steel with a yield stress of 820-830 MPa and with high weldability and toughness properties. The test specimens of both series had the same geometry. The present report concentrates on the results obtained in the investigation on the high-strength steel tubular joints.The test specimens were fabricated...... 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...

  10. Mathematical rationalization for the renal tubular transport: revised concepts.

    Science.gov (United States)

    Mioni, Roberto; Marega, Alessandra; Romano, Giulio; Montanaro, Domenico

    2017-09-01

    The current emphasis on kinetics and in situ control of molecular exchanges, across the tubular membrane, has not been paralleled by corresponding improvements in our understanding of tubular behaviour at the macroscopic level of classical physiology. In this paper, we propose a mathematical rationalization of macroscopic tubular transport by means of a principal transport equation, originating from the law of mass action between substrate and carrier. The other equations, derived from the main one, demonstrate the possibility of distinguishing between transporters with low affinity and high capacity and transporters with high affinity and low capacity. Moreover, our model formalizes both tubular reabsorption and tubular secretion. Regarding the renal calcium handling, our model confirms the two-compartment system proposed by Mioni in 1971, with some important variants, which are in agreement with the fractional reabsorptions of this cation along the tubule, as verified by micro-puncture technique. To obtain the frequency distribution of saturated tubules, we have utilized the infinitesimal analysis method, starting from the equations proposed by Smith in 1943, concluding that all titration curves result from the combined effect of enzymatic approach and anatomical heterogeneity of the nephrons. The theoretical equations included in our manuscript reflect substantial and palpable physiological mechanisms able to suggest diagnosis and therapy of some electrolyte and hormonal disorders. At the end of this paper, we highlight advantages and disadvantages detectable by comparing our mathematical approach with Marshall's and Bijvoet's methods, proposed, respectively, in 1976 and 1984.

  11. Proximal tubular dysfunction as an indicator of chronic graft dysfunction

    Directory of Open Access Journals (Sweden)

    N.O.S. Câmara

    2009-03-01

    Full Text Available New strategies are being devised to limit the impact of renal sclerosis on graft function. Individualization of immunosuppression, specifically the interruption of calcineurin-inhibitors has been tried in order to promote better graft survival once chronic graft dysfunction has been established. However, the long-term impact of these approaches is still not totally clear. Nevertheless, patients at higher risk for tubular atrophy and interstitial fibrosis (TA/IF development should be carefully monitored for tubular function as well as glomerular performance. Since tubular-interstitial impairment is an early event in TA/IF pathogenesis and associated with graft function, it seems reasonable that strategies directed at assessing tubular structural integrity and function would yield important functional and prognostic data. The measurement of small proteins in urine such as α-1-microglobulin, N-acetyl-beta-D-glucosaminidase, alpha/pi S-glutathione transferases, β-2 microglobulin, and retinol binding protein is associated with proximal tubular cell dysfunction. Therefore, its straightforward assessment could provide a powerful tool in patient monitoring and ongoing clinical assessment of graft function, ultimately helping to facilitate longer patient and graft survival associated with good graft function.

  12. Emergent patterns of collective cell migration under tubular confinement.

    Science.gov (United States)

    Xi, Wang; Sonam, Surabhi; Beng Saw, Thuan; Ladoux, Benoit; Teck Lim, Chwee

    2017-11-15

    Collective epithelial behaviors are essential for the development of lumens in organs. However, conventional assays of planar systems fail to replicate cell cohorts of tubular structures that advance in concerted ways on out-of-plane curved and confined surfaces, such as ductal elongation in vivo. Here, we mimic such coordinated tissue migration by forming lumens of epithelial cell sheets inside microtubes of 1-10 cell lengths in diameter. We show that these cell tubes reproduce the physiological apical-basal polarity, and have actin alignment, cell orientation, tissue organization, and migration modes that depend on the extent of tubular confinement and/or curvature. In contrast to flat constraint, the cell sheets in a highly constricted smaller microtube demonstrate slow motion with periodic relaxation, but fast overall movement in large microtubes. Altogether, our findings provide insights into the emerging migratory modes for epithelial migration and growth under tubular confinement, which are reminiscent of the in vivo scenario.

  13. Effect of corrosion on the buckling capacity of tubular members

    Science.gov (United States)

    Øyasæter, F. H.; Aeran, A.; Siriwardane, S. C.; Mikkelsen, O.

    2017-12-01

    Offshore installations are subjected to harsh marine environment and often have damages from corrosion. Several experimental and numerical studies were performed in the past to estimate buckling capacity of corroded tubular members. However, these studies were either based on limited experimental tests or numerical analyses of few cases resulting in semi-empirical relations. Also, there are no guidelines and recommendations in the currently available design standards. To fulfil this research gap, a new formula is proposed to estimate the residual strength of tubular members considering corrosion and initial geometrical imperfections. The proposed formula is verified with results from finite element analyses performed on several members and for varying corrosion patch parameters. The members are selected to represent the most relevant Eurocode buckling curve for tubular members. It is concluded that corrosion reduces the buckling capacity significantly and the proposed formula can be easily applied by practicing engineers without performing detailed numerical analyses.

  14. MODELING OF TUBULAR ELECTROCHEMICAL REACTOR FOR DYE REMOVAL

    Directory of Open Access Journals (Sweden)

    V. VIJAYAKUMAR

    2017-06-01

    Full Text Available The aim of the present investigation is to model a tubular electrochemical reactor for the treatment of synthetic dye wastewater. The tubular reactor was modeled and solved by finite difference method. For the model solution, the column was divided into 11 nodes in the axial direction and the variation in the radial direction has been neglected. An initial dye concentration of 200 mg L-1was taken in the reservoir. The reactor was operated in a batch with recirculation operation. Based on preliminary experiments all parameters have been optimized. The model simulation is compared with the experimental value and it is observed that the model fairly matches well with the experiment. The modeling of tubular electrochemical reactors for dye waste water treatment could be useful in the design and scale up of electrochemical process.

  15. Bmi-1 plays a critical role in the protection from acute tubular necrosis by mobilizing renal stem/progenitor cells.

    Science.gov (United States)

    Lv, Xianhui; Yu, Zhenzhen; Xie, Chunfeng; Dai, Xiuliang; Li, Qing; Miao, Dengshun; Jin, Jianliang

    2017-01-22

    The regeneration of injured tubular cell occurs primarily from intrinsic renal stem/progenitor cells (RSCs) labeled with CD24 and CD133 after acute tubular necrosis (ATN). Bmi-1 plays a crucial role in regulating self-renewal, differentiation and aging of multiple adult stem cells and progenitor cells. Bmi-1 was rapidly elevated in the induction of adult kidney regeneration by renal injury. To determine whether Bmi-1 maintained mobilization of RSCs in the protection from ATN, glycerol-rhabdomyolysis-induced ATN were performed in wild type (WT) and Bmi-1-deficient (Bmi-1 -/- ) mice. Their ATN phenotypes were analyzed; CD24 and CD133 double positive (CD24 + CD133 + ) cells were measured; and the levels of serum urea nitrogen (SUN) and serum creatinine (SCr) were detected. We found that CD24 + CD133 + RSCs were mobilized in WT ATN mice with the increased expression of Bmi-1; Bmi-1 deficiency led to increased tubular cast formation and necrosis, elevated levels of SUN and SCr, decreased tubular proliferation, and immobilized ratio of RSCs in ATN. These findings indicated that Bmi-1 played a critical role in the protection from ATN by maintaining mobilization of RSCs and would be a novel therapeutic target for preventing the progression of ATN. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Bmi-1 plays a critical role in the protection from acute tubular necrosis by mobilizing renal stem/progenitor cells

    International Nuclear Information System (INIS)

    Lv, Xianhui; Yu, Zhenzhen; Xie, Chunfeng; Dai, Xiuliang; Li, Qing; Miao, Dengshun; Jin, Jianliang

    2017-01-01

    The regeneration of injured tubular cell occurs primarily from intrinsic renal stem/progenitor cells (RSCs) labeled with CD24 and CD133 after acute tubular necrosis (ATN). Bmi-1 plays a crucial role in regulating self-renewal, differentiation and aging of multiple adult stem cells and progenitor cells. Bmi-1 was rapidly elevated in the induction of adult kidney regeneration by renal injury. To determine whether Bmi-1 maintained mobilization of RSCs in the protection from ATN, glycerol-rhabdomyolysis-induced ATN were performed in wild type (WT) and Bmi-1-deficient (Bmi-1 −/− ) mice. Their ATN phenotypes were analyzed; CD24 and CD133 double positive (CD24 + CD133 + ) cells were measured; and the levels of serum urea nitrogen (SUN) and serum creatinine (SCr) were detected. We found that CD24 + CD133 + RSCs were mobilized in WT ATN mice with the increased expression of Bmi-1; Bmi-1 deficiency led to increased tubular cast formation and necrosis, elevated levels of SUN and SCr, decreased tubular proliferation, and immobilized ratio of RSCs in ATN. These findings indicated that Bmi-1 played a critical role in the protection from ATN by maintaining mobilization of RSCs and would be a novel therapeutic target for preventing the progression of ATN.

  17. Modelling and simulation of a pervaporation process using tubular module for production of anhydrous ethanol

    Science.gov (United States)

    Hieu, Nguyen Huu

    2017-09-01

    Pervaporation is a potential process for the final step of ethanol biofuel production. In this study, a mathematical model was developed based on the resistance-in-series model and a simulation was carried out using the specialized simulation software COMSOL Multiphysics to describe a tubular type pervaporation module with membranes for the dehydration of ethanol solution. The permeance of membranes, operating conditions, and feed conditions in the simulation were referred from experimental data reported previously in literature. Accordingly, the simulated temperature and density profiles of pure water and ethanol-water mixture were validated based on existing published data.

  18. Improvement in recuperative gas cycles by means of a heat generator partly by-passing the recuperator. Application to open and closed cycles and to various kinds of energy

    International Nuclear Information System (INIS)

    Tilliette, Z.P.; Pierre, B.

    1979-01-01

    A particular arrangement applicable to open or closed recuperative gas cycles and consisting of a heat generator partly by-passing the low pressure side of the recuperator is proven to enhance advantages of gas cycles for energy production. The cogeneration of both power with a high efficiency owing to the recuperator and high temperature process heat becomes possible and economically attractive. Furthermore, additional possibilities appear for power generation by combined gas and steam or ammonia cycles. In any case the overall utilization coefficient of the primary energy is increased and the combined production of low or medium temperature heat can also be improved. The great operation flexibility of the system for combined energy generation is worth being emphasized: the by-pass arrangement involves no significant change in the operation conditions of the main turbocompressor as the heat output varies. Applications of this arrangement are made to: - open and closed gas cycle, power plants; - fossil, nuclear and solar energies. The overall heat conversion efficiency is tentatively estimated in order to appreciate the energy conversion capability of the investigated power plants

  19. A paracrine mechanism involving renal tubular cells, adipocytes and macrophages promotes kidney stone formation in a simulated metabolic syndrome environment.

    Science.gov (United States)

    Zuo, Li; Tozawa, Keiichi; Okada, Atsushi; Yasui, Takahiro; Taguchi, Kazumi; Ito, Yasuhiko; Hirose, Yasuhiko; Fujii, Yasuhiro; Niimi, Kazuhiro; Hamamoto, Shuzo; Ando, Ryosuke; Itoh, Yasunori; Zou, Jiangang; Kohri, Kenjiro

    2014-06-01

    We developed an in vitro system composed of renal tubular cells, adipocytes and macrophages to simulate metabolic syndrome conditions. We investigated the molecular communication mechanism of these cells and their involvement in kidney stone formation. Mouse renal tubular cells (M-1) were cocultured with adipocytes (3T3-L1) and/or macrophages (RAW264.7). Calcium oxalate monohydrate crystals were exposed to M-1 cells after 48-hour coculture and the number of calcium oxalate monohydrate crystals adherent to the cells was quantified. The expression of cocultured medium and M-1 cell inflammatory factors was analyzed by enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, respectively. The inflammatory markers MCP-1, OPN and TNF-α were markedly up-regulated in cocultured M-1 cells. OPN expression increased in M-1 cells cocultured with RAW264.7 cells while MCP-1 and TNF-α were over expressed in M-1 cells cocultured with 3T3-L1 cells. Coculturing M-1 cells simultaneously with 3T3-L1 and RAW264.7 cells resulted in a significant increase in calcium oxalate monohydrate crystal adherence to M-1 cells. Inflammatory cytokine changes were induced by coculturing renal tubular cells with adipocytes and/or macrophages without direct contact, indicating that crosstalk between adipocytes/macrophages and renal tubular cells was mediated by soluble factors. The susceptibility to urolithiasis of patients with metabolic syndrome might be due to aggravated inflammation of renal tubular cells triggered by a paracrine mechanism involving these 3 cell types. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. Numerical analysis on seismic behavior of reinforced concrete beam to concrete filled steel tubular column connections with ring-beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yi., E-mail: zhaoyi091218@163.com [School of Civil and Architectural Engineering, Zhongyuan University of Technology,Zhengzhou 450000 (China); Xu, Li. Hua. [School of Civil Engineering, Wuhan University, No.8, Donghu Road, WuHan 430072 (China)

    2016-06-08

    This paper presents numerical study of the seismic behavior of reinforced concrete beam to concrete filled steel tube column connections with ring-beam. The material stress-strain relations, element type and boundary condition are selected, which are consistent with actual situation. Then the seismic behavior of this type of joint are researched by ABAQUS, and finite element analyses are conducted under cyclic loading. Its parameters are discussed including thickness of steel tubular column wall, sectional dimension of the ring-beam and strength of the core concrete. The results show that the ultimate capacity of the connections is improved with sectional dimension of the ring-beam increased. In the meanwhile, the influence on skeleton curve of the joints is slight of which included thickness of steel tubular column wall and strength of the core concrete.

  1. Cultivation of micro-algae in closed tubular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gudin, C.; Bernard, A.; Chaumont, D.

    1983-11-01

    A description is presented of the three culture pilot utilities in activity under natural light, including glass tubular solar collector (30 mm diameter) in which the microalgae culture circulates. The utility is controled automatically (thermal regulation, gaseous transfers, continuous culture organization). The tests were conducted for the production of polysaccharides (Porphyridium cruentum, chlamydomonas mexicana) or hydrocarbons (Botriococcus braunii).

  2. Modeling of heat transfer in wall-cooled tubular reactors

    NARCIS (Netherlands)

    Koning, G.W.; Westerterp, K.R.

    1999-01-01

    In a pilot scale wall-cooled tubular reactor, temperature profiles have been measured with and without reaction. As a model reaction oxidation of carbon monoxide in air over a copper chromite catalyst has been used. The kinetics of this reaction have been determined separately in two kinetic

  3. The H^{-1}-norm of tubular neighbourhoods of curves

    NARCIS (Netherlands)

    Gennip, van Y.; Peletier, M.A.

    2011-01-01

    We study the H^{-1}-norm of the function 1 on tubular neighbourhoods of curves in R^2. We take the limit of small thickness epsilon, and we prove two different asymptotic results. The first is an asymptotic development for a fixed curve in the limit epsilon to 0, containing contributions from the

  4. Hemodynamic and tubular changes induced by contrast media.

    Science.gov (United States)

    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.

  5. Elevated oxidized glutathione in cystinotic proximal tubular epithelial cells.

    Science.gov (United States)

    Wilmer, Martijn J G; de Graaf-Hess, Adriana; Blom, Henk J; Dijkman, Henry B P M; Monnens, Leo A; van den Heuvel, Lambertus P; Levtchenko, Elena N

    2005-11-18

    Cystinosis, the most frequent cause of inborn Fanconi syndrome, is characterized by the lysosomal cystine accumulation, caused by mutations in the CTNS gene. To elucidate the pathogenesis of cystinosis, we cultured proximal tubular cells from urine of cystinotic patients (n = 9) and healthy controls (n = 9), followed by immortalization with human papilloma virus (HPV E6/E7). Obtained cell lines displayed basolateral polarization, alkaline phosphatase activity, and presence of aminopeptidase N (CD-13) and megalin, confirming their proximal tubular origin. Cystinotic cell lines exhibited elevated cystine levels (0.86 +/- 0.95 nmol/mg versus 0.09 +/- 0.01 nmol/mg protein in controls, p = 0.03). Oxidized glutathione was elevated in cystinotic cells (1.16 +/- 0.83 nmol/mg versus 0.29 +/- 0.18 nmol/mg protein, p = 0.04), while total glutathione, free cysteine, and ATP contents were normal in these cells. In conclusion, elevated oxidized glutathione in cystinotic proximal tubular epithelial cell lines suggests increased oxidative stress, which may contribute to tubular dysfunction in cystinosis.

  6. Tubularized incised plate technique for recurrent hypospadias: a ...

    African Journals Online (AJOL)

    management of recurrent hypospadias. Summary background ... The potential advantages of tubularized incised plate .... after a mean duration of 4.9 ± 3.1 years from the previous repair (Table 2). .... erection and the risk of infection, especially in patients older than 15 .... However, previous surgery often limits the availability ...

  7. Modeling of Unidirectional-Overloaded Transition in Catalytic Tubular Microjets

    NARCIS (Netherlands)

    Klingner, Anke; Khalil, Islam S. M.; Magdanz, Veronika; Fomin, Vladimir M.; Schmidt, Oliver G.; Misra, Sarthak

    2017-01-01

    A numerical time-resolved model is presented for predicting the transition between unidirectional and overloaded motion of catalytic tubular microjets (Ti/Fe/Pt rolled-up microtubes) in an aqueous solution of hydrogen peroxide. Unidirectional movement is achieved by periodic ejection of gas bubbles

  8. Characterization of Foam Catalysts as Packing for Tubular Reactors.

    Czech Academy of Sciences Publication Activity Database

    Lali, Farzad

    2016-01-01

    Roč. 105, JUL 2016 (2016), s. 1-9 ISSN 0255-2701 Institutional support: RVO:67985858 Keywords : overall mass transfer * foam catalyst * tubular reactor Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.234, year: 2016

  9. Importance of early audiologic assessment in distal renal tubular acidosis

    Directory of Open Access Journals (Sweden)

    Elizabeth Norgett

    2010-12-01

    Full Text Available Anand P Swayamprakasam1, Elizabeth Stover1, Elizabeth Norgett1, Katherine G Blake-Palmer1, Michael J Cunningham2, Fiona E Karet11Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK; 2Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USAAbstract: Autosomal recessive distal renal tubular acidosis is usually a severe disease of childhood, often presenting as failure to thrive in infancy. It is often, but not always, accompanied by sensorineural hearing loss, the clinical severity and age of onset of which may be different from the other clinical features. Mutations in either ATP6V1B1 or ATP6V0A4 are the chief causes of primary distal renal tubular acidosis with or without hearing loss, although the loss is often milder in the latter. We describe a kindred with compound heterozygous alterations in ATP6V0A4, where hearing loss was formally diagnosed late in both siblings such that they missed early opportunities for hearing support. This kindred highlights the importance of routine audiologic assessments of all children with distal renal tubular acidosis, irrespective either of age at diagnosis or of which gene is mutated. In addition, when diagnostic genetic testing is undertaken, both genes should be screened irrespective of current hearing status. A strategy for this is outlined.Keywords: sensorineural hearing loss, renal tubular acidosis, recessive, genetics, mutation

  10. Finite element analysis of tubular joints in offshore structures ...

    African Journals Online (AJOL)

    ... representing a 2-D model of the joint between the brace and the chord walls. This was subsequently followed but finite element analysis of six tubular joints. A global analysis was initially undertaken, then the submodel analysis carried in the areas of stress concentration. Journal of Civil Engineering, JKUAT (2001) Vol 6, ...

  11. Expansion of Tubular with Elastomers in Multilateral Wells

    Directory of Open Access Journals (Sweden)

    Md Velden

    2013-06-01

    Full Text Available The use of solid expandable tubular technology during the last decade has focused on solving many challenges in well drilling and delivery including zonal isolation, deep drilling, conservation of hole sizes, etc. not only as pioneered solution but also providing cost effective and long lasting solutions. Concurrently, the technology was extended for construction of multilateral in typical wells. The process of horizontal tubular expansion is similar to the vertical expansion of expandable tubular in down-hole environment with the addition of uniformly distributed force due to its weight. The expansion is targeted to increase its diameter such that post expansion characteristics remain within allowable limits. In this study a typical expandable tubular of 57.15 mm outer diameter and 6.35 mm wall thickness was used with two different elastomer seals of 5 and 7 mm thickness placed at equal spacing of 200 mm. The developed stress contours during expansion process clearly showed the high stress areas in the vicinity of expansion region which lies around the mandrel. These high stresses may result in excessive wear of the mandrel. It was also found out that the drawing force increases as the mandrel angle, expansion ratio, and friction coefficient increases. A mandrel angle of 20o  requires minimum expansion force and can be considered as an optimum geometrical parameter to lower the power required for expansion.

  12. Transient acute tubular dysfunction in the newborn: CT findings

    International Nuclear Information System (INIS)

    McLaughlin, M.G.; Schwartz, J.R.; Swayne, L.C.; Columbia Univ., New York; Rubenstein, J.B.; University of Medicine and Dentistry of New Jersey, Newark, NJ; Block, D.C.

    1990-01-01

    We report the CT and sonographic findings of transient acute tubular disease in a newborn infant, who was dehydrated at birth. The initial CT scan demonstrated focal areas of increased attenuation within the central portions of both kidneys, and sonography showed echogenic medullary pyramids. After adequate hydration, a follow-up examination demonstrated complete spontaneous resolution. (orig.)

  13. Renal pathophysiologic role of cortical tubular inclusion bodies.

    Science.gov (United States)

    Radi, Zaher A; Stewart, Zachary S; Grzemski, Felicity A; Bobrowski, Walter F

    2013-01-01

    Renal tubular inclusion bodies are rarely associated with drug administration. The authors describe the finding of renal cortical tubular intranuclear and intracytoplasmic inclusion bodies associated with the oral administration of a norepinephrine/serotonin reuptake inhibitor (NSRI) test article in Sprague-Dawley (SD) rats. Rats were given an NSRI daily for 4 weeks, and kidney histopathologic, ultrastructural pathology, and immunohistochemical examinations were performed. Round eosinophilic intranuclear inclusion bodies were observed histologically in the tubular epithelial cells of the renal cortex in male and female SD rats given the NSRI compound. No evidence of degeneration or necrosis was noted in the inclusion-containing renal cells. By ultrastructural pathology, inclusion bodies consisted of finely granular, amorphous, and uniformly stained nonmembrane-bound material. By immunohistochemistry, inclusion bodies stained positive for d-amino acid oxidase (DAO) protein. In addition, similar inclusion bodies were noted in the cytoplasmic tubular epithelial compartment by ultrastructural and immunohistochemical examination.  This is the first description of these renal inclusion bodies after an NSRI test article administration in SD rats. Such drug-induced renal inclusion bodies are rat-specific, do not represent an expression of nephrotoxicity, represent altered metabolism of d-amino acids, and are not relevant to human safety risk assessment.

  14. Some asymptotic properties of functions holomorphic in tubular domains

    International Nuclear Information System (INIS)

    Zavialov, B.I.

    1988-10-01

    For the function holomorphic in curved tubular domain the connection between asymptotic behaviour of real part of its boundary value at a given point of base manifold and asymptotic behaviour of the whole function from the inside of this domain is studied. (author). 3 refs

  15. Experiments in MARIUS on HTR tubular fuel with loose particles

    Energy Technology Data Exchange (ETDEWEB)

    Bosser, R; Langlet, G

    1972-06-15

    The work described on HTR tubular fuel with loose particles is the first part of a program in three points. The cell is the same in the three experiments, only particles in the fuel container are changed. The aim of the experiment is to achieve the buckling in a critical facility. A description of the techniques of measurements, calculations, and results are presented.

  16. Nerve regeneration using tubular scaffolds from biodegradable polyurethane.

    Science.gov (United States)

    Hausner, T; Schmidhammer, R; Zandieh, S; Hopf, R; Schultz, A; Gogolewski, S; Hertz, H; Redl, H

    2007-01-01

    In severe nerve lesion, nerve defects and in brachial plexus reconstruction, autologous nerve grafting is the golden standard. Although, nerve grafting technique is the best available approach a major disadvantages exists: there is a limited source of autologous nerve grafts. This study presents data on the use of tubular scaffolds with uniaxial pore orientation from experimental biodegradable polyurethanes coated with fibrin sealant to regenerate a 8 mm resected segment of rat sciatic nerve. Tubular scaffolds: prepared by extrusion of the polymer solution in DMF into water coagulation bath. The polymer used for the preparation of tubular scaffolds was a biodegradable polyurethane based on hexamethylene diisocyanate, poly(epsilon-caprolactone) and dianhydro-D-sorbitol. EXPERIMENTAL MODEL: Eighteen Sprague Dawley rats underwent mid-thigh sciatic nerve transection and were randomly assigned to two experimental groups with immediate repair: (1) tubular scaffold, (2) 180 degrees rotated sciatic nerve segment (control). Serial functional measurements (toe spread test, placing tests) were performed weekly from 3rd to 12th week after nerve repair. On week 12, electrophysiological assessment was performed. Sciatic nerve and scaffold/nerve grafts were harvested for histomorphometric analysis. Collagenic connective tissue, Schwann cells and axons were evaluated in the proximal nerve stump, the scaffold/nerve graft and the distal nerve stump. The implants have uniaxially-oriented pore structure with a pore size in the range of 2 micorm (the pore wall) and 75 x 700 microm (elongated pores in the implant lumen). The skin of the tubular implants was nonporous. Animals which underwent repair with tubular scaffolds of biodegradable polyurethanes coated with diluted fibrin sealant had no significant functional differences compared with the nerve graft group. Control group resulted in a trend-wise better electrophysiological recovery but did not show statistically significant

  17. Factor H and Properdin Recognize Different Epitopes on Renal Tubular Epithelial Heparan Sulfate

    NARCIS (Netherlands)

    Zaferani, Azadeh; Vives, Romain R.; van der Pol, Pieter; Navis, Gerjan J.; Daha, Mohamed R.; van Kooten, Cees; Lortat-Jacob, Hugues; Seelen, Marc A.; van den Born, Jacob

    2012-01-01

    During proteinuria, renal tubular epithelial cells become exposed to ultrafiltrate-derived serum proteins, including complement factors. Recently, we showed that properdin binds to tubular heparan sulfates (HS). We now document that factor H also binds to tubular HS, although to a different epitope

  18. Test of Flow Characteristics in Tubular Fuel Assembly I - Establishment of test loop and measurement validation test

    International Nuclear Information System (INIS)

    Park, Jong Hark; Chae, H. T.; Park, C.; Kim, H.

    2005-12-01

    Tubular type fuel has been developed as one of candidates for Advanced HANARO Reactor(AHR). It is necessary to test the flow characteristics such as velocity in each flow channels and pressure drop of tubular type fuel. A hydraulic test-loop to examine the hydraulic characteristics for a tubular type fuel has been designed and constructed. It consists of three parts; a) piping-loop including pump and motor, magnetic flow meter and valves etc, b) test-section part where a simulated tubular type fuel is located, and 3) data acquisition system to get reading signals from sensors or instruments. In this report, considerations during the design and installation of the facility and the selection of data acquisition sensors and instruments are described in detail. Before doing the experiment to measure the flow velocities in flow channels, a preliminary tests have been done for measuring the coolant velocities using pitot-tube and for validating the measurement accuracy as well. Local velocities of the radial direction in circular tubes are measured at regular intervals of 60 degrees by three pitot-tubes. Flow rate inside the circular flow channel can be obtained by integrating the velocity distribution in radial direction. The measured flow rate was compared to that of magnetic flow meter. According to the results, two values had a good agreement, which means that the measurement of coolant velocity by using pitot-tube and the flow rate measured by the magnetic flow meter are reliable. Uncertainty analysis showed that the error of velocity measurement by pitot-tube is less than ±2.21%. The hydraulic test-loop also can be adapted to others such as HANARO 18 and 36 fuel, in-pile system of FTL(Fuel Test Loop), etc

  19. 99mTc renal tubular function agents: Current status

    International Nuclear Information System (INIS)

    Eshima, D.; Fritzberg, A.R.; Taylor, A. Jr.

    1990-01-01

    Orthoiodohippuric (OIH) acid labeled with 131I is a widely used renal radiopharmaceutical agent and has been the standard radiopharmaceutical agent for the measurement of effective renal plasma flow (EPRF). Limitations to the routine clinical use of 131I OIH are related to the suboptimal imaging properties of the 131I radionuclide and its relatively high radiation dose. 123I has been substituted for 131I; however, its high cost and short shelf-life have limited its widespread use. Recent work has centered on the development of a new 99mTc renal tubular function agent, which would use the optimal radionuclidic properties and availability of 99mTc and combine the clinical information provided by OIH. The search for a suitable 99mTc renal tubular function agent has focused on the diamide dithiolate (N2S2), the paraaminohippuric iminodiacetic acid (PAHIDA), and the triamide mercaptide (N3S) donor ligand systems. To date, the most promising 99mTc tubular function agent is the N3S complex: 99mTc mercaptoacetyltriglycine (99mTc MAG3). Studies in animal models in diuresis, dehydration, acid or base imbalance, ischemia, and renal artery stenosis demonstrate that 99mTc MAG3 behaves similarly to 131I OIH. A simple kit formulation is available that yields the 99mTc MAG3 complex in high radiochemical purity. Studies in normal subjects and patients indicate that 99mTc MAG3 is an excellent 99mTc renal tubular agent, but its plasma clearance is only 50% to 60% that of OIH. In an effort to develop an improved 99mTc renal tubular function agent, changes have been made in the core N3S donor ligand system, but to date no agent has been synthesized that is clinically superior to 99mTc MAG3. 61 references

  20. Hyperglycemia induced damage to mitochondrial respiration in renal mesangial and tubular cells: Implications for diabetic nephropathy

    Directory of Open Access Journals (Sweden)

    Anna Czajka

    2016-12-01

    Full Text Available Damage to renal tubular and mesangial cells is central to the development of diabetic nephropathy (DN, a complication of diabetes which can lead to renal failure. Mitochondria are the site of cellular respiration and produce energy in the form of ATP via oxidative phosphorylation, and mitochondrial dysfunction has been implicated in DN. Since the kidney is an organ with high bioenergetic needs, we postulated that hyperglycemia causes damage to renal mitochondria resulting in bioenergetic deficit. The bioenergetic profiles and the effect of hyperglycemia on cellular respiration of human primary mesangial (HMCs and proximal tubular cells (HK-2 were compared in normoglycemic and hyperglycemic conditions using the seahorse bio-analyzer. In normoglycemia, HK-2 had significantly lower basal, ATP-linked and maximal respiration rates, and lower reserve capacity compared to HMCs. Hyperglycemia caused a down-regulation of all respiratory parameters within 4 days in HK-2 but not in HMCs. After 8 days of hyperglycemia, down-regulation of respiratory parameters persisted in tubular cells with compensatory up-regulated glycolysis. HMCs had reduced maximal respiration and reserve capacity at 8 days, and by 12 days had compromised mitochondrial respiration despite which they did not enhance glycolysis. These data suggest that diabetes is likely to lead to a cellular deficit in ATP production in both cell types, although with different sensitivities, and this mechanism could significantly contribute to the cellular damage seen in the diabetic kidney. Prevention of diabetes induced damage to renal mitochondrial respiration may be a novel therapeutic approach for the prevention/treatment of DN.

  1. Tubular and glomerular injury in diabetes and the impact of ACE inhibition

    DEFF Research Database (Denmark)

    Nielsen, Stine E; Sugaya, Takeshi; Tarnow, Lise

    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 or =300 mg/24 h). A control group consisted of 57 healthy individuals. The groups were matched by sex...... and duration of diabetes. In addition, U-LFABP was measured in 48 type 1 diabetic patients with diabetic nephropathy in a randomized crossover trial consisting of 2 months of treatment with 20, 40, and 60 mg lisinopril once daily in random order. RESULTS: In the cross-sectional study, levels of U-LFABP were...

  2. Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo.

    Science.gov (United States)

    Wang, Bin; Lin, Lilu; Wang, Haidong; Guo, Honglei; Gu, Yong; Ding, Wei

    2016-10-25

    The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity.

  3. Evacuated, displacement compression mold. [of tubular bodies from thermosetting plastics

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    A process of molding long thin-wall tubular bodies from thermosetting plastic molding compounds is described wherein the tubular body lengths may be several times the diameters. The process is accomplished by loading a predetermined quantity of molding compound into a female mold cavity closed at one end by a force mandrel. After closing the other end of the female mold with a balance mandrel, the loaded cavity is evacuated by applying a vacuum of from one-to-five mm pressure for a period of fifteen-to-thirty minutes. The mold temperature is raised to the minimum temperature at which the resin constituent of the compound will soften or plasticize and a pressure of 2500 psi is applied.

  4. Luminous effectiveness of tubular light-guides in tropics

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Renal tubular acidosis complicated with hyponatremia due to cortisol insufficiency

    OpenAIRE

    Izumi, Yuichiro; Nakayama, Yushi; Onoue, Tomoaki; Inoue, Hideki; Mukoyama, Masashi

    2015-01-01

    Adrenocortical insufficiency such as occurs in Addison's disease causes hyponatremia and renal tubular acidosis (RTA). Hyponatremia results from both aldosterone and cortisol insufficiency. RTA is due to aldosterone insufficiency. The involvement of cortisol in RTA is unclear. Here, we report a woman in her 70s who was admitted to our hospital with severe hyponatremia (106 mEq/l) and RTA. The patient exhibited low plasma cortisol levels with little response to rapid adrenocorticotropic hormon...

  7. Oscillations of manometric tubular springs with rigid end

    Science.gov (United States)

    Cherentsov, D. A.; Pirogov, S. P.; Dorofeev, S. M.; Ryabova, Y. S.

    2018-05-01

    The paper presents a mathematical model of attenuating oscillations of manometric tubular springs (MTS) taking into account the rigid tip. The dynamic MTS model is presented in the form of a thin-walled curved rod oscillating in the plane of curvature of the central axis. Equations for MTS oscillations are obtained in accordance with the d’Alembert principle in projections onto the normal and tangential. The Bubnov-Galerkin method is used to solve the equations obtained.

  8. A tubular flux-switching permanent magnet machine

    Science.gov (United States)

    Wang, J.; Wang, W.; Clark, R.; Atallah, K.; Howe, D.

    2008-04-01

    The paper describes a novel tubular, three-phase permanent magnet brushless machine, which combines salient features from both switched reluctance and permanent magnet machine technologies. It has no end windings and zero net radial force and offers a high power density and peak force capability, as well as the potential for low manufacturing cost. It is, therefore, eminently suitable for a variety of applications, ranging from free-piston energy converters to active vehicle suspensions.

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

    OpenAIRE

    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...

  10. Distal renal tubular acidosis in recurrent renal stone formers

    DEFF Research Database (Denmark)

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

    1989-01-01

    Renal acidification ability was examined in 90 recurrent renal stone formers, using fasting morning urinary pH levels followed by a short ammonium chloride loading test in subjects with pH levels above 6.0. Fifteen patients (16.6%) revealed a distal renal tubular acidification defect: one patient......, this has important therapeutic implications. The pathological sequence in renal stone formers with dRTA is discussed....

  11. Sjögren syndrome presenting with hypopotassemic periodic paralysis due to renal tubular acidosis

    Science.gov (United States)

    Ataoglu, Esra Hayriye; Demir, Betul; Tuna, Mazhar; Çavus, Bilger; Cetin, Faik; Temiz, Levent Umit; Ozturk, Savas; Yenigun, Mustafa

    2012-01-01

    Summary Background: Sjögren syndrome (SS) is an autoimmune-lymphoproliferative disorder characterized by mononuclear cell infiltration of exocrine glands. Clinically, Sjögren syndrome (SS) has a wide spectrum, varying from autoimmune exocrinopathy to systemic involvement. There have been few cases reporting that primary SS developed with distal renal tubular acidosis clinically. Case Report: Here, we present a case with primary Sjögren syndrome accompanied by hypopotassemic paralysis due to renal tubular acidosis. Severe hypopotassemia, hyperchloremic metabolic acidosis, alkaline urine and disorder in urinary acidification test were observed in the biochemical examination of the 16-year-old female patient, who had applied to our clinic for extreme loss of muscle force. After the examinations it was determined that the patient had developed Type 1 RTA (distal RTA) due to primary Sjögren syndrome. Potassium and alkaline replacement was made and an immediate total recovery was achieved. Conclusions: Hypopotassemic paralysis due to primary Sjögren syndrome is a rare but severe disorder that could lead to death if not detected early and cured appropriately. Thus, effective treatment should be immediately initiated in cases where severe hypopotassemia is accompanied by metabolic acidosis, and the cases should also be examined for extraglandular involvement of SS. PMID:23569525

  12. Continuous Polyol Synthesis of Metal and Metal Oxide Nanoparticles Using a Segmented Flow Tubular Reactor (SFTR

    Directory of Open Access Journals (Sweden)

    Andrea Testino

    2015-06-01

    Full Text Available Over the last years a new type of tubular plug flow reactor, the segmented flow tubular reactor (SFTR, has proven its versatility and robustness through the water-based synthesis of precipitates as varied as CaCO3, BaTiO3, Mn(1−xNixC2O4·2H2O, YBa oxalates, copper oxalate, ZnS, ZnO, iron oxides, and TiO2 produced with a high powder quality (phase composition, particle size, and shape and high reproducibility. The SFTR has been developed to overcome the classical problems of powder production scale-up from batch processes, which are mainly linked with mass and heat transfer. Recently, the SFTR concept has been further developed and applied for the synthesis of metals, metal oxides, and salts in form of nano- or micro-particles in organic solvents. This has been done by increasing the working temperature and modifying the particle carrying solvent. In this paper we summarize the experimental results for four materials prepared according to the polyol synthesis route combined with the SFTR. CeO2, Ni, Ag, and Ca3(PO42 nanoparticles (NPs can be obtained with a production rate of about 1–10 g per h. The production was carried out for several hours with constant product quality. These findings further corroborate the reliability and versatility of the SFTR for high throughput powder production.

  13. Tubular transport and metabolism of cimetidine in chicken kidneys

    International Nuclear Information System (INIS)

    Rennick, B.; Ziemniak, J.; Smith, I.; Taylor, M.; Acara, M.

    1984-01-01

    Renal tubular transport and renal metabolism of [ 14 C]cimetidine (CIM) were investigated by unilateral infusion into the renal portal circulation in chickens (Sperber technique). [ 14 C]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 [ 14 C]CIM with decreasing potency: CIM, ranitidine, thiamine, procainamide, guanidine and choline. CIM inhibited the transport of [ 14 C]thiamine, [ 14 C]amiloride and [ 14 C]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

  14. Mechanical testing of adherence of stacked layers in tubular geometry

    Energy Technology Data Exchange (ETDEWEB)

    Correia, L.A.; Schuring, E.W.; Van Delft, Y.C. [ECN Energy Efficiency in the Industry, Petten (Netherlands)

    2007-09-15

    For the development of new molecular separation technologies strong robust tubular membrane systems are required. The fragile membranes, however, need a strong defect free support such as a porous asymmetric ceramic tube. Mechanical failure of these ceramic membrane systems during manufacturing and operation is mainly caused by delamination of the stacked layers. Therefore development is focused on improving the adherence. As no standard mechanical test for tubular samples is available yet, a new tensile test was developed to facilitate the current research. The most important components in the new equipment is a test tool with a curvature matching that of the test sample and a sample casing that align and guide the test tool during the tensile test. With this tensile test the manufacturing procedure for the ECN standard tubular {alpha}-alumina support was optimized. Firing the asymmetric support at 1300C resulted in the highest mechanical strength for the support system with cohesive fracture in the support tube. With the test developed the process condition could be identified where the material of the support tube is the weakest link in the support system.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Plastic deformation of tubular crystals by dislocation glide.

    Science.gov (United States)

    Beller, Daniel A; Nelson, David R

    2016-09-01

    Tubular crystals, two-dimensional lattices wrapped into cylindrical topologies, arise in many contexts, including botany and biofilaments, and in physical systems such as carbon nanotubes. The geometrical principles of botanical phyllotaxis, describing the spiral packings on cylinders commonly found in nature, have found application in all these systems. Several recent studies have examined defects in tubular crystals associated with crystalline packings that must accommodate a fixed tube radius. Here we study the mechanics of tubular crystals with variable tube radius, with dislocations interposed between regions of different phyllotactic packings. Unbinding and separation of dislocation pairs with equal and opposite Burgers vectors allow the growth of one phyllotactic domain at the expense of another. In particular, glide separation of dislocations offers a low-energy mode for plastic deformations of solid tubes in response to external stresses, reconfiguring the lattice step by step. Through theory and simulation, we examine how the tube's radius and helicity affects, and is in turn altered by, the mechanics of dislocation glide. We also discuss how a sufficiently strong bending rigidity can alter or arrest the deformations of tubes with small radii.

  17. Filament winding technique, experiment and simulation analysis on tubular structure

    Science.gov (United States)

    Quanjin, Ma; Rejab, M. R. M.; Kaige, Jiang; Idris, M. S.; Harith, M. N.

    2018-04-01

    Filament winding process has emerged as one of the potential composite fabrication processes with lower costs. Filament wound products involve classic axisymmetric parts (pipes, rings, driveshafts, high-pressure vessels and storage tanks), non-axisymmetric parts (prismatic nonround sections and pipe fittings). Based on the 3-axis filament winding machine has been designed with the inexpensive control system, it is completely necessary to make a relative comparison between experiment and simulation on tubular structure. In this technical paper, the aim of this paper is to perform a dry winding experiment using the 3-axis filament winding machine and simulate winding process on the tubular structure using CADWIND software with 30°, 45°, 60° winding angle. The main result indicates that the 3-axis filament winding machine can produce tubular structure with high winding pattern performance with different winding angle. This developed 3-axis winding machine still has weakness compared to CAWIND software simulation results with high axes winding machine about winding pattern, turnaround impact, process error, thickness, friction impact etc. In conclusion, the 3-axis filament winding machine improvements and recommendations come up with its comparison results, which can intuitively understand its limitations and characteristics.

  18. Thermodynamic model and parametric analysis of a tubular SOFC module

    Science.gov (United States)

    Campanari, Stefano

    Solid oxide fuel cells (SOFCs) have been considered in the last years as one of the most promising technologies for very high-efficiency electric energy generation from natural gas, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. Among the SOFC technologies, tubular SOFC stacks with internal reforming have emerged as one of the most mature technology, with a serious potential for a future commercialization. In this paper, a thermodynamic model of a tubular SOFC stack, with natural gas feeding, internal reforming of hydrocarbons and internal air preheating is proposed. In the first section of the paper, the model is discussed in detail, analyzing its calculating equations and tracing its logical steps; the model is then calibrated on the available data for a recently demonstrated tubular SOFC prototype plant. In the second section of the paper, it is carried out a detailed parametric analysis of the stack working conditions, as a function of the main operating parameters. The discussion of the results of the thermodynamic and parametric analysis yields interesting considerations about partial load SOFC operation and load regulation, and about system design and integration with gas turbine cycles.

  19. Creep crack growth verification testing in alloy 800H tubular components

    International Nuclear Information System (INIS)

    Hunter, C.P.; Hurst, R.C.

    1992-01-01

    A method for determining the creep crack growth, CCG, and stress rupture behaviour of Alloy 800H tubular components containing longitudinal notches at 800deg C is described. The presence of the notch is found to systematically weaken the tube, the degree of weaking dependent upon the notch length and depth. The creep crack growth rates, determined from a specially adapted potential drop technique are compared with those obtained from conventional compact tension type specimens. Using the stress intensity factor, K 1 , and the C * parameter as the basis of comparison it is found that the latter gives excellent correlation between the specimen and component behaviour. Finally attention is drawn to the potential dangers of predicting the component creep crack growth behaviour from the data obtained using conventional specimens for a structure sensitive material such as Alloy 800H and conversely to the advantages of the component type CCG tests developed in the present work. (orig.)

  20. Mathematical modeling of methyl ester concentration distribution in a continuous membrane tubular reactor and comparison with conventional tubular reactor

    Science.gov (United States)

    Talaghat, M. R.; Jokar, S. M.; Modarres, E.

    2017-10-01

    The reduction of fossil fuel resources and environmental issues made researchers find alternative fuels include biodiesels. One of the most widely used methods for production of biodiesel on a commercial scale is transesterification method. In this work, the biodiesel production by a transesterification method was modeled. Sodium hydroxide was considered as a catalyst to produce biodiesel from canola oil and methanol in a continuous tubular ceramic membranes reactor. As the Biodiesel production reaction from triglycerides is an equilibrium reaction, the reaction rate constants depend on temperature and related linearly to catalyst concentration. By using the mass balance for a membrane tubular reactor and considering the variation of raw materials and products concentration with time, the set of governing equations were solved by numerical methods. The results clearly show the superiority of membrane reactor than conventional tubular reactors. Afterward, the influences of molar ratio of alcohol to oil, weight percentage of the catalyst, and residence time on the performance of biodiesel production reactor were investigated.

  1. Experimental analysis of performance degradation of micro-tubular solid oxide fuel cells fed by different fuel mixtures

    Science.gov (United States)

    Calise, F.; Restucccia, G.; Sammes, N.

    This paper analyzes the thermodynamic and electrochemical dynamic performance of an anode supported micro-tubular solid oxide fuel cell (SOFC) fed by different types of fuel. The micro-tubular SOFC used is anode supported, consisting of a NiO and Gd 0.2Ce 0.8O 2- x (GDC) cermet anode, thin GDC electrolyte, and a La 0.6Sr 0.4Co 0.2Fe 0.8O 3- y (LSCF) and GDC cermet cathode. The fabrication of the cells under investigation is briefly summarized, with emphasis on the innovations with respect to traditional techniques. Such micro-tubular cells were tested using a Test Stand consisting of: a vertical tubular furnace, an electrical load, a galvanostast, a bubbler, gas pipelines, temperature, pressure and flow meters. The tests on the micro-SOFC were performed using H 2, CO, CH 4 and H 2O in different combinations at 550 °C, to determine the cell polarization curves under several load cycles. Long-term experimental tests were also performed in order to assess degradation of the electrochemical performance of the cell. Results of the tests were analyzed aiming at determining the sources of the cell performance degradation. Authors concluded that the cell under investigation is particularly sensitive to the carbon deposition which significantly reduces cell performance, after few cycles, when fed by light hydrocarbons. A significant performance degradation is also detected when hydrogen is used as fuel. In this case, the authors ascribe the degradation to the micro-cracks, the change in materials crystalline structure and problems with electrical connections.

  2. Dragon (Repulsive Guidance Molecule RGMb) Inhibits E-cadherin Expression and Induces Apoptosis in Renal Tubular Epithelial Cells*

    Science.gov (United States)

    Liu, Wenjing; Li, Xiaoling; Zhao, Yueshui; Meng, Xiao-Ming; Wan, Chao; Yang, Baoxue; Lan, Hui-Yao; Lin, Herbert Y.; Xia, Yin

    2013-01-01

    Dragon is one of the three members of the repulsive guidance molecule (RGM) family, i.e. RGMa, RGMb (Dragon), and RGMc (hemojuvelin). We previously identified the RGM members as bone morphogenetic protein (BMP) co-receptors that enhance BMP signaling. Our previous studies found that Dragon is highly expressed in the tubular epithelial cells of mouse kidneys. However, the roles of Dragon in renal epithelial cells are yet to be defined. We now show that overexpression of Dragon increased cell death induced by hypoxia in association with increased cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 levels in mouse inner medullary collecting duct (IMCD3) cells. Dragon also inhibited E-cadherin expression but did not affect epithelial-to-mesenchymal transition induced by TGF-β in IMCD3 cells. Previous studies suggest that the three RGM members can function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. Dragon expression in the kidney was up-regulated by unilateral ureteral obstruction in mice. Compared with wild-type mice, heterozygous Dragon knock-out mice exhibited 45–66% reduction in Dragon mRNA expression, decreased epithelial apoptosis, and increased tubular E-cadherin expression and had attenuated tubular injury after unilateral ureteral obstruction. Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial apoptosis both in vitro and in vivo. PMID:24052264

  3. Dragon (repulsive guidance molecule RGMb) inhibits E-cadherin expression and induces apoptosis in renal tubular epithelial cells.

    Science.gov (United States)

    Liu, Wenjing; Li, Xiaoling; Zhao, Yueshui; Meng, Xiao-Ming; Wan, Chao; Yang, Baoxue; Lan, Hui-Yao; Lin, Herbert Y; Xia, Yin

    2013-11-01

    Dragon is one of the three members of the repulsive guidance molecule (RGM) family, i.e. RGMa, RGMb (Dragon), and RGMc (hemojuvelin). We previously identified the RGM members as bone morphogenetic protein (BMP) co-receptors that enhance BMP signaling. Our previous studies found that Dragon is highly expressed in the tubular epithelial cells of mouse kidneys. However, the roles of Dragon in renal epithelial cells are yet to be defined. We now show that overexpression of Dragon increased cell death induced by hypoxia in association with increased cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 levels in mouse inner medullary collecting duct (IMCD3) cells. Dragon also inhibited E-cadherin expression but did not affect epithelial-to-mesenchymal transition induced by TGF-β in IMCD3 cells. Previous studies suggest that the three RGM members can function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. Dragon expression in the kidney was up-regulated by unilateral ureteral obstruction in mice. Compared with wild-type mice, heterozygous Dragon knock-out mice exhibited 45-66% reduction in Dragon mRNA expression, decreased epithelial apoptosis, and increased tubular E-cadherin expression and had attenuated tubular injury after unilateral ureteral obstruction. Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial apoptosis both in vitro and in vivo.

  4. Experimental Research on Seismic Performance of Four-Element Variable Cross-Sectional Concrete Filled Steel Tubular Laced Columns

    Science.gov (United States)

    Ou, Zhijing; Lin, Jianmao; Chen, Shengfu; Lin, Wen

    2017-10-01

    A total of 7 experimental tests were conducted to investigate seismic performance of four element variable cross-sectional Concrete Filled Steel Tubular (CFST) laced columns. The experimental parameters are longitudinal slope and arrangement type of lacing tubes. The rules on hysteresis loop, ductility, energy expenditure, and stiffness degradation of specimens are researched. Test results indicate that all specimens have good seismic performance; their hysteresis loops are full without obvious shrinkage. With the increase of longitudinal slope, the horizontal carrying capacity increases, energy dissipation capacity improve, and there is slightly increase in stiffness degradation. The influence of arrangement type of lacing tubes on displacement ductility of specimens is big.

  5. A young woman with recurrent kidney stones: questions on hypokalaemic tubular acidosis

    Directory of Open Access Journals (Sweden)

    Jill Vanmassenhove

    2017-04-01

    Full Text Available This paper discusses the diagnostic and therapeutic approach to the problem of a young woman presenting with recurrent kidney stones. In the clinical work-up, a hypokalaemic normal anion gap metabolic acidosis was found. The diagnostic tests to solve this common clinical problem and some therapeutic recommendations are discussed. Question on hypokalaemic tubular acidosis: 1. What is the significance of the plasma anion gap (PAG? 2. How does one appreciate the respiratory component of the acid base status? 3. How does one perform tests for tubular acidification disturbances? 4. What is the pathogenesis of distal tubular acidification ­disturbances? 5. What is the explanation of the hypokalaemia in distal ­tubular acidosis? 6. What is the pathogenesis of nephrolithiasis in distal tubular acidosis? 7. How does one treat a patient with distal tubular acidosis and recurrent nephrolithiasis?

  6. Drill pipes and casings utilizing multi-conduit tubular; Flerkanals roerstreng

    Energy Technology Data Exchange (ETDEWEB)

    Curlett, H.B.

    1997-04-23

    The invention relates to a multi-conduit tubular having fluid conduits and electrical conduits, with associated surface fluid and electrical commutators, and downhole sensors for providing surface monitors with instantaneous formation data. Each tubular includes a plurality of uniform linear conduits there through, with a gasket seal plate interposed between joined tubular for assuring a high pressure seal between joined conduits. the seal plate includes an intermediate electrical connector for connecting electrical conduit connectors of one tubular to another. A coupling collar with uniform diameter internal coarse and fine threads joins the tubular ends having similar threads by differential thread action without respective tubular rotation. Each tubular end includes an inter-engaging index recess and index lug, and drive recesses and lugs for maintaining angular registry of the tubular string and for driving one drill tubular with another. A fluid commutator includes a rotating shaft with passages connected to the tubular conduits, and rotating in a manifold having annular grooves in communication with the shaft passages and external fluid sources. An adaptor couples each commutator shaft passage to one or more tubular conduits. Slip rings on a quill shaft and stationary brush means provide electrical continuity from the electrical conduit wires to surface equipment. A cross-over sub includes formation parameter sensors and telemetry equipment in a blocked off portion of a fluid conduit. An annular accumulator connected with the well bore annulus applies a pressure thereto in response to downhole sensors to change the effective density of the drill mud. The multi-conduit tubular is further adapted for use as a well casing to provide downhole access of a plurality of fluids and electrical parameter sensors. 28 figs.

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

    OpenAIRE

    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...

  8. The role of duplex stainless steels for downhole tubulars

    International Nuclear Information System (INIS)

    Francis, R.

    1993-01-01

    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 H 2 S 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

  9. The rebirth of interest in renal tubular function.

    Science.gov (United States)

    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. Copyright © 2016 the American Physiological Society.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Vibration analysis and sound field characteristics of a tubular ultrasonic radiator.

    Science.gov (United States)

    Liang, Zhaofeng; Zhou, Guangping; Zhang, Yihui; Li, Zhengzhong; Lin, Shuyu

    2006-12-01

    A sort of tubular ultrasonic radiator used in ultrasonic liquid processing is studied. The frequency equation of the tubular radiator is derived, and its radiated sound field in cylindrical reactor is calculated using finite element method and recorded by means of aluminum foil erosion. The results indicate that sound field of tubular ultrasonic radiator in cylindrical reactor appears standing waves along both its radial direction and axial direction, and amplitudes of standing waves decrease gradually along its radial direction, and the numbers of standing waves along its axial direction are equal to the axial wave numbers of tubular radiator. The experimental results are in good agreement with calculated results.

  12. [Grading of tumors in the tubular digestive tract : Esophagus, stomach, colon and rectum].

    Science.gov (United States)

    Bläker, H

    2016-07-01

    Grading of tumors located in the tubular digestive tract is an integral component of pathology assessment reports but is subordinate to the histological typing of tumors with respect to the prognostic significance. Tumor grading has not been shown to be an independent prognostic marker for most tumor entities in the gastrointestinal tract; however, it may be relevant for further routine treatment decision making in early Union Internationale Contre le Cancer (UICC) stage cancers in which the prognosis for patients is less dominated by advanced tumor spread. Owing to the more favorable prognosis of microsatellite instability in colorectal cancer, the World Health Organization (WHO) has recommended that poorly differentiated tumors should be tested and graded as low grade (G1/G2) when microsatellite instability is detected. This recommendation has been integrated into the German S3 guidelines for colorectal cancers. Accordingly, microsatellite instability testing for grading purposes should become routine practice.

  13. Theoretical flow investigations of an all glass evacuated tubular collector

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    Heat transfer and flow structures inside all glass evacuated tubular collectors for different operating conditions are investigated by means of computational fluid dynamics. The investigations are based on a collector design with horizontal tubes connected to a vertical 14 manifold channel. Three...... the highest efficiency, the optimal inlet flow rate was around 0.4-1 kg/min, the flow structures in the glass tubes were relatively uninfluenced by the inlet flow rate, Generally, the results showed only small variations in the efficiencies. This indicates that the collector design is well working for most...

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

    International Nuclear Information System (INIS)

    Bruner, F.; Lattanzi, L.; Borghesi, P.

    1996-01-01

    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

  15. Screening renal stone formers for distal renal tubular acidosis

    DEFF Research Database (Denmark)

    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...... 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...

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

    KAUST Repository

    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.

  17. Nano-tubular cellulose for bioprocess technology development.

    Science.gov (United States)

    Koutinas, Athanasios A; Sypsas, Vasilios; Kandylis, Panagiotis; Michelis, Andreas; Bekatorou, Argyro; Kourkoutas, Yiannis; Kordulis, Christos; Lycourghiotis, Alexis; Banat, Ibrahim M; Nigam, Poonam; Marchant, Roger; Giannouli, Myrsini; Yianoulis, Panagiotis

    2012-01-01

    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.

  18. Rhabdomyolysis with acute tubular necrosis following occupational inhalation of thinners.

    Science.gov (United States)

    Ngajilo, D; Ehrlich, R

    2017-07-01

    Thinners are mixtures of organic solvents commonly containing toluene, xylene, acetone, hexane, benzene and methyl isobutyl ketone. This report describes a case of rhabdomyolysis with acute tubular necrosis and renal failure, most likely attributable to toluene, following occupational exposure to thinners while cleaning a steel water tank. These adverse health effects have previously been reported following acute poisoning or intentional inhalation by drug abusers, but rarely in the occupational setting. Poor working conditions, lack of health and safety training and delayed treatment contributed to the onset and severity of the patient's complications. This case emphasizes the need for strict control measures, including adequate ventilation, training on working in confined spaces, appropriate personal protective equipment and emergency rescue procedures in such settings. In addition, rhabdomyolysis, acute tubular necrosis and renal failure should be added to safety data material as possible complications of excessive inhalation of thinners. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Advances in tubular solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Carbohydrates in Ankistrodesmus braunii biomass cultivated in tubular photobioreactors

    Directory of Open Access Journals (Sweden)

    Ana Lucía Morocho-Jácome

    2017-12-01

    Full Text Available The great need for microalgae biomass production in tubular photobioreactors has increased for use in biofuels, pharmaceuticals and even cosmetic applications. In order to better understand the potential applications of this material, it is imperative to know in detail its composition. Ankistrodesmus braunii was cultivated in 3.5 L tubular air-lift photobioreactors using 10 mM sodium nitrate as nitrogen source in batch mode at 60 µmol photons m-2 s-1. The maximum biomass concentration (Xm and the biomass productivity (PX reached at 6th day of cultivation was 1249 ± 72 mg L-1 and 165 ± 13 mg L-1 d-1, respectively. Carbohydrates productivity expressed in terms of glucose, galactose and glucose+galactose (1:1 were 2.57 ± 0.04, 4.12 ± 0.06 and 3.22 ± 0.05 mg L-1 d-1, respectively. Results show a statistical difference that was found between carbohydrate productivity values expressed as glucose, galactose and glucose+galactose (1:1.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Dynamic modeling of temperature change in outdoor operated tubular photobioreactors.

    Science.gov (United States)

    Androga, Dominic Deo; Uyar, Basar; Koku, Harun; Eroglu, Inci

    2017-07-01

    In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values. The heat transferred to the reactor was mainly through radiation: the radiative heat absorbed by the reactor medium, ground radiation, air radiation, and solar (direct and diffuse) radiation, while heat loss was mainly through the heat transfer to the cooling water and forced convection. The amount of heat transferred by reflected radiation and metabolic activities of the bacteria and pump work was negligible. Counter-current cooling was more effective in controlling reactor temperature than co-current cooling. The model developed identifies major heat transfer mechanisms in outdoor operated tubular photobioreactors, and accurately predicts temperature changes in these systems. This is useful in determining cooling duty under transient conditions and scaling up photobioreactors. The photobioreactor design and the thermal modeling were carried out and experimental results obtained for the case study of photofermentative hydrogen production by Rhodobacter capsulatus, but the approach is applicable to photobiological systems that are to be operated under outdoor conditions with significant cooling demands.

  3. Additive manufacturing of patient-specific tubular continuum manipulators

    Science.gov (United States)

    Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

    2015-03-01

    Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

  4. Radiologic findings of tubular adenoma of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Mi Gyoung; Oh, Ki Keun [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-10-01

    Tubular adenoma (TA) is known as a rare lesion of the breast which is difficult to diagnosis preoperatively because of its rarity and similarity to fibroadenoma. Hence, our purpose is to suggest the characteristic sonographic features for its correct diagnosis. We retrospectively analyzed the clinical data and mammographic and sonographic findings. of seven patients(mean age, 23) who during the previous five years had presented at our hospital with pathologically-proven tubular adenoma. TA was misdiagnosed as fibroadenoma, since on physical examination of these young females, the lesions presented a palpable, non-tender mass. Mammographically, they showed a well defined mass similar to fibroadenoma. However, sonographic findings were characteristic of TA and compared to fibroadenoma, showed a well demarcated and smooth bordered mass with transverse long axis, posterior enhancement and homogeneous lower internal echogenecity. No case showed lateral wall refractive shadowing. In young females, the clinical and mammographic findings of TA are similar to those of fibroadenoma. However, sonographic findings of TA can, be helpful in the differential diagnosis of this entity and fibroadenoma.

  5. Nano-tubular cellulose for bioprocess technology development.

    Directory of Open Access Journals (Sweden)

    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.

  6. Radiologic findings of tubular adenoma of the breast

    International Nuclear Information System (INIS)

    Jeong, Mi Gyoung; Oh, Ki Keun

    1996-01-01

    Tubular adenoma (TA) is known as a rare lesion of the breast which is difficult to diagnosis preoperatively because of its rarity and similarity to fibroadenoma. Hence, our purpose is to suggest the characteristic sonographic features for its correct diagnosis. We retrospectively analyzed the clinical data and mammographic and sonographic findings. of seven patients(mean age, 23) who during the previous five years had presented at our hospital with pathologically-proven tubular adenoma. TA was misdiagnosed as fibroadenoma, since on physical examination of these young females, the lesions presented a palpable, non-tender mass. Mammographically, they showed a well defined mass similar to fibroadenoma. However, sonographic findings were characteristic of TA and compared to fibroadenoma, showed a well demarcated and smooth bordered mass with transverse long axis, posterior enhancement and homogeneous lower internal echogenecity. No case showed lateral wall refractive shadowing. In young females, the clinical and mammographic findings of TA are similar to those of fibroadenoma. However, sonographic findings of TA can, be helpful in the differential diagnosis of this entity and fibroadenoma

  7. DEVELOPMENT OF TECHNICAL DECISIONS FOR HEAT SUPPLY WITH TUBULAR GAS HEATERS

    Directory of Open Access Journals (Sweden)

    IRODOV V. F.

    2017-05-01

    Full Text Available Annotation. Problems formulation. The problem that is solved is the development of autonomous heat supply systems that reduce the capital costs of construction and increase the efficiency of the use of energy resources. One of the ways to solve this problem is the use of tubular gas heaters. For this, it is necessary to develop new technical solutions for heat supply with tubular gas heaters, as well as scientific and methodological support for the development, construction and operation of heat supply systems with tubular gas heaters. Analysis of recent research. Preliminary studies of infrared tubular gas heaters are considered, which were used to heat industrial enterprises with sufficiently high premises. The task was to extend the principles of heat supply by means of tubular heaters for heating air, water and heating medium in relatively low rooms. Goal and tasks. To lay out the development of technical solutions for heat supply with tubular gas heaters, which increase the efficiency and reliability of heat supply systems and extend the use of tubular gas heaters in heat supply. Results. Technical solutions for heat supply with tubular gas heaters have made it possible to extend their applications for heating air, water and heating medium in relatively low rooms. Scientific novelty. New technical solutions for heat supply with tubular gas heaters increase the efficiency of using fuel and energy resources at low capital costs. Practical significance. Technical solutions for heat supply using tubular heaters have the potential for wide application in the heat supply of industrial, public and residential facilities. Conclusions. For two decades, new technical solutions for heat supply with tubular gas heaters have been developed, which increase the efficiency and reliability of heat supply systems and can be widely used for autonomous heating.

  8. In vitro generation of renal tubular epithelial cells from fibroblasts: implications for precision and regenerative medicine in nephrology.

    Science.gov (United States)

    Wyatt, Christina M; Dubois, Nicole

    2017-02-01

    Prior efforts to generate renal epithelial cells in vitro have relied on pluripotent or bone marrow-derived mesenchymal stem cells. A recent publication in Nature Cell Biology describes the generation of induced tubular epithelial cells from fibroblasts, potentially offering a novel platform for personalized drug toxicity screening and in vitro disease modeling. This report serves as a promising proof of principle study and opens future research directions, including the optimization of the reprogramming process, efficient translation to adult human fibroblasts, and the generation of highly specific functional renal cell types. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  9. Effect of section shape on frequencies of natural oscillations of tubular springs

    Science.gov (United States)

    Pirogov, S. P.; Chuba, A. Yu; Cherentsov, D. A.

    2018-05-01

    The necessity of determining the frequencies of natural oscillations of manometric tubular springs is substantiated. Based on the mathematical model and computer program, numerical experiments were performed that allowed us to reveal the effect of geometric parameters on the frequencies of free oscillations of manometric tubular springs.

  10. On Energy Balance and Production Costs in Tubular and Flat Panel Photobioreactors

    NARCIS (Netherlands)

    Norsker, N.H.; Barbosa, M.J.; Vermue, M.H.; Wijffels, R.H.

    2012-01-01

    Reducing mixing in both flat panel and tubular photobioreactors can result in a positive net energy balance with state-of-the-art technology and Dutch weather conditions. In the tubular photobioreactor, the net energy balance becomes positive at velocities <0.3 ms-1, at which point the biomass

  11. 78 FR 77421 - Certain Oil Country Tubular Goods From India: Preliminary Affirmative Countervailing Duty...

    Science.gov (United States)

    2013-12-23

    ..., Saudi Arabia, Taiwan, Thailand, the Republic of Turkey, Ukraine, and the Socialist Republic of Vietnam... DEPARTMENT OF COMMERCE International Trade Administration [C-533-858] Certain Oil Country Tubular... producers and exporters of certain oil tubular goods (OCTG) from India. The period of investigation is...

  12. 78 FR 77420 - Certain Oil Country Tubular Goods From the Republic of Turkey: Preliminary Negative...

    Science.gov (United States)

    2013-12-23

    ..., the Republic of the Philippines, Saudi Arabia, Taiwan, Thailand, the Republic of Turkey, Ukraine, and... DEPARTMENT OF COMMERCE International Trade Administration [C-489-817] Certain Oil Country Tubular... provided to producers and exporters of certain oil tubular goods (OCTG) from the Republic of Turkey (Turkey...

  13. Gamma flux responsive self-powered detector with a tubular emitter

    International Nuclear Information System (INIS)

    Goldstein, N.P.; Todt, W.H.

    1982-01-01

    A gamma-sensitive flux detector comprises tubular emitter, an insulating core within the emitter and an insulating layer about the emitter, and a tubular conductive collector electrode about the insulating layer. The emitter material may be platinum, lead, bismuth, tantalum, tungsten; platinum preferred

  14. Tubular Carcinoma of the Breast: Advantages and Limitations of Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Filipa Vilaverde

    2016-01-01

    Full Text Available Tubular carcinoma of the breast is a rare variant of invasive ductal carcinoma. We report a case of 42-year-old asymptomatic female with a histopathological proven multifocal tubular carcinoma, studied by mammography, Tomosynthesis, Ultrasound, and Magnetic Resonance. Herein, we discuss the advantages and limitations of Tomosynthesis, an emerging imaging technique, in this particular case.

  15. 76 FR 39071 - Certain Oil Country Tubular Goods From the People's Republic of China: Rescission of...

    Science.gov (United States)

    2011-07-05

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-944] Certain Oil Country Tubular... administrative review of the countervailing duty order on certain oil country tubular goods (``OCTG'') from the... subject to administrative protective order (``APO'') of their responsibility concerning the disposition of...

  16. Tubular Carcinoma of the Breast: Advantages and Limitations of Breast Tomosynthesis

    Science.gov (United States)

    Rocha, Ana; Reis, Alcinda

    2016-01-01

    Tubular carcinoma of the breast is a rare variant of invasive ductal carcinoma. We report a case of 42-year-old asymptomatic female with a histopathological proven multifocal tubular carcinoma, studied by mammography, Tomosynthesis, Ultrasound, and Magnetic Resonance. Herein, we discuss the advantages and limitations of Tomosynthesis, an emerging imaging technique, in this particular case. PMID:28116205

  17. Compressibility effects in packed and open tubular gas and supercritical fluid chromatography

    NARCIS (Netherlands)

    Janssen, J.G.M.; Snijders, H.M.J.; Cramers, C.A.; Schoenmakers, P.J.

    1992-01-01

    The influence of the pressure drop on the efficiency and speed of anal. in packed and open tubular supercrit. fluid chromatog. (SFC) is described: methods previously developed to describe the effects of mobile phase compressibility on the performance of open tubular columns in SFC have been extended

  18. Tubular array, dielectric, conductivity and electrochemical properties of biodegradable gel polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sudhakar, Y.N. [Department of Chemistry, Manipal Institute of Technology, Manipal, Karnataka (India); Selvakumar, M., E-mail: chemselva78@gmail.com [Department of Chemistry, Manipal Institute of Technology, Manipal, Karnataka (India); Bhat, D. Krishna [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore (India)

    2014-02-15

    Highlights: • A new finding of tubular array of 10–20 μm in length and 1–2 μm in thickness of gel polymer electrolyte (GPE) having 2.2 × 10{sup −3} S cm{sup −1} conductivity is reported. • Thermal and electrochemical characterizations of GPEs show good interaction among the polymer, plasticizer and salt. • GPE based supercapacitor demonstrates high capacitance of 186 F g{sup −1}. • Low temperature studies did not influence much on capacitance values obtained from AC impedance studies. • Charge–discharge exhibits high capacity with excellent cyclic stability and energy density. -- Abstract: A supercapacitor based on a biodegradable gel polymer electrolyte (GPE) has been fabricated using guar gum (GG) as the polymer matrix, LiClO{sub 4} as the doping salt and glycerol as the plasticizer. The scanning electron microscopy (SEM) images of the gel polymer showed an unusual tubular array type surface morphology. FTIR, DSC and TGA results of the GPE indicated good interaction between the components used. Highest ionic conductivity and lowest activation energy values were 2.2 × 10{sup −3} S cm{sup −1} and 0.18 eV, respectively. Dielectric studies revealed ionic behavior and good capacitance with varying frequency of the GPE system. The fabricated supercapacitor showed a maximum specific capacitance value of 186 F g{sup −1} using cyclic voltammetry. Variation of temperature from 273 K to 293 K did not significantly influence the capacitance values obtained from AC impedance studies. Galvanostatic charge–discharge study of supercapacitor indicated that the device has good stability, high energy density and power density.

  19. Final Report SBIR Phase I, Improvement of Properties of Tubular Internal-Tin Nb3Sn

    International Nuclear Information System (INIS)

    Gregory, Eric

    2009-01-01

    Final report of SBIR to develop an economical process that can produce the best material for high field magnets to be used in the next generation of accelerators. The overall problem is to develop an economical process that can produce material with good properties for high field magnets to be used in the future for High Energy Physics (HEP) applications. The Internal-tin (IT) process, called by some the Restacked Rod process (RRP), for making Nb 3 Sn has been very successful in achieving high J c properties in the high field region. As a result it has been used effectively in several high field magnets. Originally, when this material was processed to give the highest J c it behaved unstably in the low field region and consequently did not perform as well in magnets designed for intermediate field applications. In this field range, the Powder-in-Tube (PIT) material, that has a lower d eff and a high RRR, behaved more reliably. The IT material has been improved to give better stability in the low field range and consequently the process offers a considerable challenge to the PIT process for application in both types of magnets. The PIT material has two principal drawbacks - lower J c and high cost. Work has been carried out to address these two problems and Supergenics I LLC has reported, on a low cost tubular process that is under development. It has fewer problems than the (IT) process in making low d eff materials and is of lower cost than both the IT and PIT processes. At the present stage, the J c 's that have been achieved are similar to those of the PIT material but are below those of the IT material. The purpose of the work proposed here is to improve the properties of the material made by this tubular process that has been described previously.

  20. Endovascular Tubular Stent-Graft Placement for Isolated Iliac Artery Aneurysms

    International Nuclear Information System (INIS)

    Okada, Takuya; Yamaguchi, Masato; Kitagawa, Atsushi; Kawasaki, Ryota; Nomura, Yoshikatsu; Okita, Yutaka; Sugimura, Kazuro; Sugimoto, Koji

    2012-01-01

    Purpose: To evaluate the safety, efficacy, and mid-term outcomes of endovascular tubular stent-graft placement for repair of isolated iliac artery aneurysms (IAAs). Materials and Methods: Between January 2002 and March 2010, 20 patients (7 women and 13 men; mean age 74 years) underwent endovascular repair of 22 isolated IAAs. Two patients underwent endovascular repair for bilateral aneurysms. Ten para-anastomotic aneurysms (45%) developed after open abdominal aortic aneurysm (AAA) repair with an aorto-iliac graft, and 12 were true aneurysms (55%). Eleven straight and 11 tapered stent-grafts were placed. Contrast-enhanced computed tomography (CT) was performed to detect complications and evaluate aneurysmal shrinkage at week 1, 3, 6, and 12 months and once every year thereafter. Non–contrast-enhanced CT was performed in seven patients with chronic kidney disease. Results: All procedures were successful, without serious complications, during the mean (range) follow-up period of 746 days (47–2651). Type II endoleak not requiring treatment was noted in one patient. The mean (SD) diameters of the true and para-anastomotic aneurysms significantly (p < 0.05) decreased from 42.0 (9.3) to 36.9 (13.6) mm and from 40.1 (13.0) to 33.6 (15.8) mm, respectively; the mean (SD) shrinkage rates were 15.1% (20.2%) and 18.9% (22.4%), respectively. The primary patency rate was 100%, and no secondary interventions were required. Four patients (21%) developed transient buttock claudication, and one patient (5%) developed colorectal ischaemia, which was treated conservatively. Conclusion: Endovascular tubular stent-graft placement for the repair of isolated IAAs is safe and efficacious. Tapered stent-grafts of various sizes are required for accurate placement.

  1. PENGURANGAN KADAR CO2 MENGGUNAKAN SPIRULINA PLATENSIS DALAM TUBULAR BIOREACTOR

    Directory of Open Access Journals (Sweden)

    Zainal Syam Arifin

    2015-06-01

    Full Text Available Increasing the population impact on increasing energy demand. On the other hand, the energy generation industry has been blamed as one of the contributors of carbon dioxide about 25% of total CO2 emissions worldwide. Meanwhile, the production of biogas, which aims to address the increasing need of energy, produces carbon dioxide in the range of 25–50% by volume. To overcome this, a cheap method, optimum and efficient as well as environmentally friendly in reducing CO2 levels by using Spirulina platensis is needed. This research aims to created a mathematical models and found the optimum flow rate to reduced levels of CO2 by using Spirulina platensis. This study used a glass tubular bioreactor (D = 2.6 cm at a temperature of 30°C and irradiated with a fluorescent lamp Philips TL 36 Watt, color temperature: 6,200K cool daylight, light output: 2,600 lm, 72 lm/W. Tubular reactor was placed in a box lined with silver foil walls on three sides. With mathematical models of tubular reactor, the reaction rate constants could be predicted. Based on calculations of data and graphs, optimum volumetric velocity could also be predicted. Variation of flowrate to observed the reduction rate of CO2 was 0.25 mL/sec, 0.35 mL/sec, 0.5 mL/sec, 0.75 mL/sec, 1 mL/sec. Carbon source was 99.99% CO2.Observations of Spirulina growth was made on the flow rate of 0.25 mL/sec at the initial levels of dry weight 2.1208 g/L. The results of this study indicated that the low flowratewas a more effective way to reduced carbon dioxide levels using Spirulina platensis (= 2.82×10-4 sec-1. The highest conversion was obtained at a volumetric flow rate of 0.25 mL/sec and optimum speeds in the range of 0.3 to 0.4 mL/sec. The rate of incoming CO2 flux should be less than 0.047 mL/cm2.detik. Specific Growth Rate (µ of Spirulina platensis in this study was 2.56×10-2 minute-1.   Keywords: Spirulina platensis, a vertical tubular bioreactor, CO2 reduction     ABSTRAK

  2. Steel-reinforced concrete-filled steel tubular columns under axial and lateral cyclic loading

    Science.gov (United States)

    Farajpourbonab, Ebrahim; Kute, Sunil Y.; Inamdar, Vilas M.

    2018-03-01

    SRCFT columns are formed by inserting a steel section into a concrete-filled steel tube. These types of columns are named steel-reinforced concrete-filled steel tubular (SRCFT) columns. The current study aims at investigating the various types of reinforcing steel section to improve the strength and hysteresis behavior of SRCFT columns under axial and lateral cyclic loading. To attain this objective, a numerical study has been conducted on a series of composite columns. First, FEM procedure has been verified by the use of available experimental studies. Next, eight composite columns having different types of cross sections were analyzed. For comparison purpose, the base model was a CFT column used as a benchmark specimen. Nevertheless, the other specimens were SRCFT types. The results indicate that reinforcement of a CFT column through this method leads to enhancement in load-carrying capacity, enhancement in lateral drift ratio, ductility, preventing of local buckling in steel shell, and enhancement in energy absorption capacity. Under cyclic displacement history, it was observed that the use of cross-shaped reinforcing steel section causes a higher level of energy dissipation and the moment of inertia of the reinforcing steel sections was found to be the most significant parameter affecting the hysteresis behavior of SRCFT columns.

  3. Process for the fixing of a metallic end piece on a tubular component

    International Nuclear Information System (INIS)

    Charpin, Jean.

    1975-01-01

    Under this invention the process makes it possible to joint a tubular component and in particular a tubular filter and an end piece, with a connection of great mechanical strength, perfectly leak proof and with excellent corrosion resistance, particularly with respect to fluorinated by-products. This process is therefore of great worth in fixing to a bearer a thin ceramic compound tubular filter element, since such a filter can be used in particular for the separation of uranium isotopes by gaseous diffusion and for the separation of hydrocarbons in petrochemicals. To this end, the process under consideration is characterised in that it consists in depositing a layer of ceramic material, by hot projection, at the end of the tubular element and in sealing the end piece to the end of the tubular element by the hot projection of a ceramic or metallic substance [fr

  4. Fabrication of cathode supported tubular solid oxide electrolysis cell for high temperature steam electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Le; Wang, Shaorong; Qian, Jiqin; Xue, Yanjie; Liu, Renzhu

    2011-01-15

    In recent years, hydrogen has been identified as a potential alternative fuel and energy carrier for the future energy supply. Water electrolysis is one of the important hydrogen production technologies which do not emit carbon dioxide. High temperature steam electrolysis (HTSE) consumes even less electrical energy than low temperature water electrolysis. Theoretically, HTSE using solid oxide electrolysis cells (SOEC) can efficiently utilize renewable energy to produce hydrogen, and it is also possible to operate the SOEC in reverse mode as the solid oxide fuel cell (SOFC) to produce electricity. Tubular SOFC have been widely investigated. In this study, tubular solid oxide cells were fabricated by dip-coating and cosintering techniques. In SOEC mode, results suggested that steam ratio had a strong impact on the performance of the tubular cell; the tubular SOEC preferred to be operated at high steam ratio in order to avoid concentration polarization. The microstructure of the tubular SOEC should therefore be optimized for high temperature steam electrolysis.

  5. Research on typical topologies of a tubular horizontal-gap passive magnetic levitation vibration isolator

    Directory of Open Access Journals (Sweden)

    Zhou Yiheng

    2017-01-01

    Full Text Available Magnetic levitation vibration isolators have attracted more and more attention in the field of high-precision measuring and machining equipment. In this paper, we describe a tubular horizontal-gap passive magnetic levitation vibration isolator. Four typical topologies of the tubular horizontal-gap passive magnetic levitation vibration isolator are proposed. The analytical expression of magnetic force is derived. The relationship between levitation force, force density, force ripple and major structural parameters are analysed by finite element method, which is conductive to the design and optimization of the tubular horizontal-gap passive magnetic levitation vibration isolator. The force characteristics of different topologies of the tubular horizontal-gap passive magnetic levitation vibration isolator are compared and evaluated from the aspect of force density, force ripple and manufacturability. In comparison with conventional passive magnetic levitation vibration isolators, the proposed tubular horizontal-gap passive magnetic levitation vibration isolator shows advantage in higher force density.

  6. Construction and characterization of an electrospun tubular scaffold for small-diameter tissue-engineered vascular grafts: a scaffold membrane approach.

    Science.gov (United States)

    Hu, Jin-Jia; Chao, Wei-Chih; Lee, Pei-Yuan; Huang, Chih-Hao

    2012-09-01

    Based on a postulate that the microstructure of a scaffold can influence that of the resulting tissue and hence its mechanical behavior, we fabricated a small-diameter tubular scaffold (∼3 mm inner diameter) that has a microstructure similar to the arterial media using a scaffold membrane approach. Scaffold membranes that contain randomly oriented, moderately aligned, or highly aligned fibers were fabricated by collecting electrospun poly([epsilon]-caprolactone) fibers on a grounded rotating drum at three different drum rotation speeds (250, 1000, and 1500 rpm). Membranes of each type were wrapped around a small-diameter mandrel to form the tubular scaffolds. Particularly, the tubular scaffolds with three different off-axis fiber angles (30, 45, and 60 degree) were formed using membranes that contain aligned fibers. These scaffolds were subjected to biaxial mechanical testing to examine the effects of fiber directions as well as the distribution of fiber orientations on their mechanical properties. The circumferential elastic modulus of the tubular scaffold was closely related to the fiber directions; the larger the off-axis fiber angle the greater the circumferential elastic modulus. The distribution of fiber orientations, on the other hand, manifested itself in the mechanical behavior via the Poisson effect. Similar to cell sheet-based vascular tissue engineering, tubular cell-seeded constructs were prepared by wrapping cell-seeded scaffold membranes, alleviating the difficulty associated with cell seeding in electrospun scaffolds. Histology of the construct illustrated that cells were aligned to the fiber directions in the construct, demonstrating the potential to control the microstructure of tissue-engineered vascular grafts using the electrospun scaffold membrane. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Renal transplantant blood flow in patients with acute tubular necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Huic, D; Crnkovic, S; Bubic-Filipi, L J; Grosev, D; Dodig, P; Porapat, M; Puretic, Z [Univ. Hospital Rebro, Zagreb (Croatia)

    1997-09-01

    The aim of this study was to investigate the quantity of renal transport blood flow in patients affected by acute tubular necrosis (ATN). During the four years period two hundred and thirty-three studies were performed using {sup 99m}Tc pertechnetate and {sup 131}I - OIH. Renal blood flow was calculated from the first-pass time activity curves generated over the kidney and aorta and expressed as a percentage of cardiac output (RBF/CO). Renal transplant blood flow is clearly diminished in ATN, similar as in acute rejection, and significantly related to the graft function, what means that RBF/CO value could potentially serve as a prognostic factor in the graft function recovery from ATN.

  8. A Phase of Liposomes with Entangled Tubular Vesicles

    Science.gov (United States)

    Chiruvolu, Shivkumar; Warriner, Heidi E.; Naranjo, Edward; Idziak, Stefan H. J.; Radler, Joachim O.; Plano, Robert J.; Zasadzinski, Joseph A.; Safinya, Cyrus R.

    1994-11-01

    An equilibrium phase belonging to the family of bilayer liposomes in ternary mixtures of dimyristoylphosphatidylcholine (DMPC), water, and geraniol (a biological alcohol derived from oil-soluble vitamins that acts as a cosurfactant) has been identified. Electron and optical microscopy reveal the phase, labeled Ltv, to be composed of highly entangled tubular vesicles. In situ x-ray diffraction confirms that the tubule walls are multilamellar with the lipids in the chain-melted state. Macroscopic observations show that the Ltv phase coexists with the well-known L_4 phase of spherical vesicles and a bulk L_α phase. However, the defining characteristic of the Ltv phase is the Weissenberg rod climbing effect under shear, which results from its polymer-like entangled microstructure.

  9. Scavenging energy from human motion with tubular dielectric polymer

    Science.gov (United States)

    Jean-Mistral, Claire; Basrour, Skandar

    2010-04-01

    Scavenging energy from human motion is a challenge to supply low consumption systems for sport or medical applications. A promising solution is to use electroactive polymers and especially dielectric polymers to scavenge mechanical energy during walk. In this paper, we present a tubular dielectric generator which is the first step toward an integration of these structures into textiles. For a 10cm length and under a strain of 100%, the structure is able to scavenge 1.5μJ for a poling voltage of 200V and up to 40μJ for a poling voltage of 1000V. A 30cm length structure is finally compared to our previous planar structure, and the power management module for those structures is discussed.

  10. Amelogenesis Imperfecta with Distal Renal Tubular Acidosis: A Novel Syndrome?

    Science.gov (United States)

    Misgar, R A; Hassan, Z; Wani, A I; Bashir, M I

    2017-01-01

    Amelogenesis imperfecta (AI) is a heterogeneous group of inherited dental enamel defects. It has rarely been reported in association with multiorgan syndromes and metabolic disorders. The metabolic disorders that have been reported in association with AI include hypocalciuria, impaired urinary concentrating ability, and Bartter-like syndrome. In literature, only three cases of AI and distal renal tubular acidosis (dRTA) have been described: two cases in adults and a solitary case in the pediatric age group. Here, we report a child with AI presenting with dRTA; to the best of our knowledge, our reported case is the only second such case in pediatric age group. Our case highlights the importance of recognizing the possibility of renal abnormalities in patients with AI as it will affect the long-term prognosis.

  11. Amelogenesis imperfecta with distal renal tubular acidosis: A novel syndrome?

    Directory of Open Access Journals (Sweden)

    R A Misgar

    2017-01-01

    Full Text Available Amelogenesis imperfecta (AI is a heterogeneous group of inherited dental enamel defects. It has rarely been reported in association with multiorgan syndromes and metabolic disorders. The metabolic disorders that have been reported in association with AI include hypocalciuria, impaired urinary concentrating ability, and Bartter-like syndrome. In literature, only three cases of AI and distal renal tubular acidosis (dRTA have been described: two cases in adults and a solitary case in the pediatric age group. Here, we report a child with AI presenting with dRTA; to the best of our knowledge, our reported case is the only second such case in pediatric age group. Our case highlights the importance of recognizing the possibility of renal abnormalities in patients with AI as it will affect the long-term prognosis.

  12. Tubular Scaffold with Shape Recovery Effect for Cell Guide Applications

    Directory of Open Access Journals (Sweden)

    Kazi M. Zakir Hossain

    2015-07-01

    Full Text Available Tubular scaffolds with aligned polylactic acid (PLA fibres were fabricated for cell guide applications by immersing rolled PLA fibre mats into a polyvinyl acetate (PVAc solution to bind the mats. The PVAc solution was also mixed with up to 30 wt % β-tricalcium phosphate (β-TCP content. Cross-sectional images of the scaffold materials obtained via scanning electron microscopy (SEM revealed the aligned fibre morphology along with a significant number of voids in between the bundles of fibres. The addition of β-TCP into the scaffolds played an important role in increasing the void content from 17.1% to 25.3% for the 30 wt % β-TCP loading, which was measured via micro-CT (µCT analysis. Furthermore, µCT analyses revealed the distribution of aggregated β-TCP particles in between the various PLA fibre layers of the scaffold. The compressive modulus properties of the scaffolds increased from 66 MPa to 83 MPa and the compressive strength properties decreased from 67 MPa to 41 MPa for the 30 wt % β-TCP content scaffold. The scaffolds produced were observed to change into a soft and flexible form which demonstrated shape recovery properties after immersion in phosphate buffered saline (PBS media at 37 °C for 24 h. The cytocompatibility studies (using MG-63 human osteosarcoma cell line revealed preferential cell proliferation along the longitudinal direction of the fibres as compared to the control tissue culture plastic. The manufacturing process highlighted above reveals a simple process for inducing controlled cell alignment and varying porosity features within tubular scaffolds for potential tissue engineering applications.

  13. Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

    Science.gov (United States)

    Zhu, Honggeng; Zhang, Rentian; Deng, Dongsheng; Feng, Xusong; Yao, Linbi

    2010-06-01

    Since the flow in tubular pumping systems is basically along axial direction and passes symmetrically through the impeller, most satisfying the basic hypotheses in the design of impeller and having higher pumping system efficiency in comparison with vertical pumping system, they are being widely applied to low-head pumping engineering. In a pumping station, the fluctuation of water levels in the sump and discharge pool is most common and at most time the pumping system runs under off-design conditions. Hence, the operation of pump has to be flexibly regulated to meet the needs of flow rates, and the selection of regulation method is as important as that of pump to reduce operation cost and achieve economic operation. In this paper, the three dimensional time-averaged Navier-Stokes equations are closed by RNG κ-ɛ turbulent model, and two tubular pumping systems with different regulation methods, equipped with the same pump model but with different designed system structures, are numerically simulated respectively to predict the pumping system performances and analyze the influence of regulation device and help designers make final decision in the selection of design schemes. The computed results indicate that the pumping system with blade-adjusting device needs longer suction box, and the increased hydraulic loss will lower the pumping system efficiency in the order of 1.5%. The pumping system with permanent magnet motor, by means of variable speed regulation, obtains higher system efficiency partly for shorter suction box and partly for different structure design. Nowadays, the varied speed regulation is realized by varied frequency device, the energy consumption of which is about 3˜4% of output power of the motor. Hence, when the efficiency of variable frequency device is considered, the total pumping system efficiency will probably be lower.

  14. Cross-flow filtration of yeast extract with multi-tubular membrane module and rotating-disk membrane module; Makukaitengata heibanmaku module to tankanjomaku module ni yoru kobo hasaieki no cross flow roka

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, K.; Shimizu, Y.; Watanabe, a. [Toto Ltd., Kitakyushu (Japan)

    1994-09-15

    A membrane separation experiment was made with multi-tubular membrane module and rotating-disk membrane module to study the cross-flow filtration of yeast extract. The membrane was an alumina precision filtration membrane with 0.15 micron m diameter pores. A multi-tubular membrane which was 19 in number of channels and 0.113{sup 2} in effective membrane area was fitted to the multi-tubular membrane module. A rotating-disk membrane which was 0.071m{sup 2} in effective membrane area was fitted to the rotating-disk membrane module. Judging from the concentration speed and factor, the rotating-disk type is more advantageous in concentrating the suspension than the multi-tubular type. The soluble high-molecular component was more easily filtrated through the rotating-disk type, which is judged attributable to its possible operation at a high flow rate on the membrane surface without necessitating a high-flow rate circulation pump. As compared with the conventional cross-filtration type, the rotating-disk type gives a high permeate flux even at a high concentration factor. 11 refs., 5 figs.

  15. Regulation of proximal tubular cell differentiation and proliferation in primary culture by matrix stiffness and ECM components.

    Science.gov (United States)

    Chen, Wan-Chun; Lin, Hsi-Hui; Tang, Ming-Jer

    2014-09-15

    To explore whether matrix stiffness affects cell differentiation, proliferation, and transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in primary cultures of mouse proximal tubular epithelial cells (mPTECs), we used a soft matrix made from monomeric collagen type I-coated polyacrylamide gel or matrigel (MG). Both kinds of soft matrix benefited primary mPTECs to retain tubular-like morphology with differentiation and growth arrest and to evade TGF-β1-induced EMT. However, the potent effect of MG on mPTEC differentiation was suppressed by glutaraldehyde-induced cross-linking and subsequently stiffening MG or by an increasing ratio of collagen in the soft mixed gel. Culture media supplemented with MG also helped mPTECs to retain tubular-like morphology and a differentiated phenotype on stiff culture dishes as soft MG did. We further found that the protein level and activity of ERK were scaled with the matrix stiffness. U-0126, a MEK inhibitor, abolished the stiff matrix-induced dedifferentiation and proliferation. These data suggest that the ERK signaling pathway plays a vital role in matrix stiffness-regulated cell growth and differentiation. Taken together, both compliant property and specific MG signals from the matrix are required for the regulation of epithelial differentiation and proliferation. This study provides a basic understanding of how physical and chemical cues derived from the extracellular matrix regulate the physiological function of proximal tubules and the pathological development of renal fibrosis. Copyright © 2014 the American Physiological Society.

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

    DEFF Research Database (Denmark)

    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...... 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. Undulating tubular liposomes through incorporation of a synthetic skin ceramide into phospholipid bilayers.

    Science.gov (United States)

    Xu, Peng; Tan, Grace; Zhou, Jia; He, Jibao; Lawson, Louise B; McPherson, Gary L; John, Vijay T

    2009-09-15

    Nonspherical liposomes were prepared by doping L-alpha-phosphatidylcholine (PC) with ceramide VI (a skin lipid). Cryo-transmission electron microscopy shows the liposome shape changing from spherical to an undulating tubular morphology, when the amount of ceramide VI is increased. The formation of tubular liposomes is energetically favorable and is attributed to the association of ceramide VI with PC creating regions of lower curvature. Since ceramides are the major component of skin lipids in the stratum corneum, tubular liposomes containing ceramide may potentially serve as self-enhanced nanocarriers for transdermal delivery.

  18. Functional characterization of apical transporters expressed in rat proximal tubular cells (PTCs) in primary culture.

    Science.gov (United States)

    Nakanishi, Takeo; Fukushi, Akimasa; Sato, Masanobu; Yoshifuji, Mayuko; Gose, Tomoka; Shirasaka, Yoshiyuki; Ohe, Kazuyo; Kobayashi, Masato; Kawai, Keiichi; Tamai, Ikumi

    2011-12-05

    Since in vitro cell culture models often show altered apical transporter expression, they are not necessarily suitable for the analysis of renal transport processes. Therefore, we aimed here to investigate the usefulness of primary-cultured rat proximal tubular cells (PTCs) for this purpose. After isolation of renal cortical cells from rat kidneys, PTCs were enriched and the gene expression and function of apical transporters were analyzed by means of microarray, RT-PCR and uptake experiments. RT-PCR confirmed that the major apical transporters were expressed in rat PTCs. Na(+)-dependent uptake of α-methyl-d-glucopyranoside (αMG), ergothioneine and carnitine by the PTCs suggests functional expression of Sglts, Octn1 and Octn2, respectively. Inhibition of pH-dependent glycylsarcosine uptake by low concentration of cephalexin, which is a β-lactam antibiotics recognized by Pepts, indicates a predominant role of high affinity type Pept2, but not low affinity type Pept1, in the PTCs. Moreover, the permeability ratio of [(14)C]αMG (apical to basolateral/basolateral to apical) across PTCs was 4.3, suggesting that Sglt-mediated reabsorptive transport is characterized. In conclusion, our results indicate that rat PTCs in primary culture are found to be a promising in vitro model to evaluate reabsorption processes mediated at least by Sglts, Pept2, Octn1 and Octn2.

  19. Renal Tubular Acidosis Secondary to FK506 in Living Donor Liver Transplantation: A Case Report

    Directory of Open Access Journals (Sweden)

    Keiko Ogita

    2003-10-01

    Full Text Available FK506 is an immunosuppressant that is thought to be less nephrotoxic than cyclosporine A. However, complications due to renal tubular acidosis (RTA have recently been reported. We report a case of RTA secondary to FK506 administration in liver transplantation. A 6-month-old girl was treated with FK506 after undergoing living donor liver transplantation for fulminant hepatitis. On postoperative day 17, she demonstrated hyperkalaemia and metabolic acidosis; she was diagnosed to have hyperkalaemic distal RTA with aldosterone deficiency (type IV. Intravenous sodium bicarbonate and furosemide, and intrarectal calcium polystyrenesulfonate were administered to correct the acidosis and promote potassium secretion. Thereafter, the FK506 concentration in whole blood gradually decreased, and the hyperkalaemia and metabolic acidosis following RTA improved. RTA is one type of nephrotoxicity induced by FK506, and it is reversible in mild cases when appropriately treated. The mechanism of RTA induced by FK506 has not yet been clearly elucidated. Surgeons and physicians should therefore be aware of the potential for RTA to occur with FK506 after any organ transplantation. The treatment for acidosis and hyperkalaemia should be started as soon as RTA is diagnosed, and the dosage of FK506 should also be reduced if possible.

  20. Biofiksasi CO2 Oleh Mikroalga Chlamydomonas sp dalam Photobioreaktor Tubular

    Directory of Open Access Journals (Sweden)

    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

  1. Lovastatin prevents cisplatin-induced activation of pro-apoptotic DNA damage response (DDR) of renal tubular epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Krüger, Katharina; Ziegler, Verena; Hartmann, Christina; Henninger, Christian [Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf (Germany); Thomale, Jürgen [Institute of Cell Biology, University Duisburg-Essen, 45122 Essen (Germany); Schupp, Nicole [Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf (Germany); Fritz, Gerhard, E-mail: fritz@uni-duesseldorf.de [Institute of Toxicology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf (Germany)

    2016-02-01

    The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury. - Highlights: • Lovastatin blocks ATM/ATR-regulated DDR of tubular cells following CisPt treatment. • Lovastatin attenuates CisPt-induced activation of protein kinase ATM in vitro. • Statin-mediated DDR inhibition is independent of initial DNA damage formation. • Statin-mediated blockage of Cis

  2. Lovastatin prevents cisplatin-induced activation of pro-apoptotic DNA damage response (DDR) of renal tubular epithelial cells

    International Nuclear Information System (INIS)

    Krüger, Katharina; Ziegler, Verena; Hartmann, Christina; Henninger, Christian; Thomale, Jürgen; Schupp, Nicole; Fritz, Gerhard

    2016-01-01

    The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury. - Highlights: • Lovastatin blocks ATM/ATR-regulated DDR of tubular cells following CisPt treatment. • Lovastatin attenuates CisPt-induced activation of protein kinase ATM in vitro. • Statin-mediated DDR inhibition is independent of initial DNA damage formation. • Statin-mediated blockage of Cis

  3. The Association of Albuminuria With Tubular Reabsorption of Uric Acid : Results From a General Population Cohort

    NARCIS (Netherlands)

    Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

    Background-Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and

  4. Design, Fabrication and Test of a Full Scale Copper Tubular Combustion Chamber

    National Research Council Canada - National Science Library

    Cooley, Christine

    2002-01-01

    This paper presents the design fabrication and test of a full scale copper tubular combustion chamber as an enabling technology for future application in a high thrust upper-stage expander-cycle engine...

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

    DEFF Research Database (Denmark)

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

    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...... of 80 mu m thickness with corrugated metallic electrodes on both sides. Tubular actuators are manufactured by rolling the DE sheets in a cylindrical shape. The electromechanical characteristics of such actuators are modeled based on equilibrium pressure equation. The model is validated with experimental...... 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...

  6. Large tubular colonic duplication in an adult treated with a small midline incision

    Science.gov (United States)

    Yong, Yuen Geng; Jung, Kyung Uk; Cho, Yong Beom; Yun, Seong Hyeon; Kim, Hee Cheol; Lee, Woo Yong

    2012-01-01

    Tubular colonic duplication presenting in adults is rare and difficult to diagnose preoperatively. Only a few cases have been reported in the literature. We report a case of a 29-year-old lady presenting with a long history of chronic constipation, abdominal mass and repeated episodes of abdominal pain. The abdominal-pelvic computed tomography scan showed segmental bowel wall thickening thought to be small bowel, and dilatation with stasis of intraluminal content. The provisional diagnosis was small bowel duplication. She was scheduled for single port laparoscopic resection. However, a T-shaped tubular colonic duplication at sigmoid colon was found intraoperatively. Resection of the large T-shaped tubular colonic duplication containing multiple impacted large fecaloma and primary anastomosis was performed. There was no perioperative complication. We report, herein, the case of a T-shaped tubular colonic duplication at sigmoid colon in an adult who was successfully treated through mini-laparotomy assisted by single port laparoscopic surgery. PMID:22403754

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

    DEFF Research Database (Denmark)

    Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro

    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 caused by mutations in STIM1. A common pattern of involvement was found in STIM1-mutated patients...... 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...

  8. Tubular adenoma of the breast in a pregnant girl: report on a case.

    Science.gov (United States)

    Palnaes Hansen, C; Fahrenkrug, L; Hastrup, N

    1991-12-01

    A rare case of a tubular breast adenoma in a 13-year-old pregnant girl is presented. The tumor which developed during pregnancy measured 10 x 8 x 4 cm, was well demarcated and could be totally removed.

  9. Design, analysis, and test of an active tubular interface

    Science.gov (United States)

    Elspass, Wilfried J.; Eerme, M.; Paradies, R.; Resch, Martin

    1997-06-01

    Space missions require higher and higher performance such as high pointing accuracy and stability, and high shape precision. Passive damping means often cannot fulfill the requirements. Besides space applications at the same time numerous applications in machine design require higher accuracy. For a lot of applications the passive measures come up against limits. Active technologies have to be considered more often. Active mechanical components are more and more used as a necessary step towards adaptive structures. Active mechanical interfaces are simpler systems having very useful applications and can be used as kind of test benches in order to master the most exacting technologies. The main advantages of such an active interface are the following: (1) state-of- the-art sensors and actuators can be used, (2) the mechanical design of the interface is conventional, (3) the passive behavior of the system is not deteriorated, (4) the design is compact and rather easy to integrate, (5) easy repair (replacement) of the active mechanical part, (6) standardization of the interfaces results in cost reductions. An important property in such intermediate step is that no major redesign of the conventionally designed mechanical structure should be needed. The design, numerical analysis, manufacturing and test of a fully integrated active tubular interface (ATI) is presented. The design of the ATI includes the optimal laminate stacking sequence with respect to maximum deformation efficiency. The results of an active damping application, an antenna support beam, including the controller layout are discussed.

  10. The tubular separate first wall for ITER EDA

    International Nuclear Information System (INIS)

    Pizzuto, A.; Riccardi, B.; Salpietro, E.

    1994-01-01

    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/m 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

  11. Soft tubular microfluidics for 2D and 3D applications

    Science.gov (United States)

    Xi, Wang; Kong, Fang; Yeo, Joo Chuan; Yu, Longteng; Sonam, Surabhi; Dao, Ming; Gong, Xiaobo; Teck Lim, Chwee

    2017-10-01

    Microfluidics has been the key component for many applications, including biomedical devices, chemical processors, microactuators, and even wearable devices. This technology relies on soft lithography fabrication which requires cleanroom facilities. Although popular, this method is expensive and labor-intensive. Furthermore, current conventional microfluidic chips precludes reconfiguration, making reiterations in design very time-consuming and costly. To address these intrinsic drawbacks of microfabrication, we present an alternative solution for the rapid prototyping of microfluidic elements such as microtubes, valves, and pumps. In addition, we demonstrate how microtubes with channels of various lengths and cross-sections can be attached modularly into 2D and 3D microfluidic systems for functional applications. We introduce a facile method of fabricating elastomeric microtubes as the basic building blocks for microfluidic devices. These microtubes are transparent, biocompatible, highly deformable, and customizable to various sizes and cross-sectional geometries. By configuring the microtubes into deterministic geometry, we enable rapid, low-cost formation of microfluidic assemblies without compromising their precision and functionality. We demonstrate configurable 2D and 3D microfluidic systems for applications in different domains. These include microparticle sorting, microdroplet generation, biocatalytic micromotor, triboelectric sensor, and even wearable sensing. Our approach, termed soft tubular microfluidics, provides a simple, cheaper, and faster solution for users lacking proficiency and access to cleanroom facilities to design and rapidly construct microfluidic devices for their various applications and needs.

  12. Design and analysis of tubular permanent magnet linear wave generator.

    Science.gov (United States)

    Si, Jikai; Feng, Haichao; Su, Peng; Zhang, Lufeng

    2014-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Standing wave brass-PZT square tubular ultrasonic motor.

    Science.gov (United States)

    Park, Soonho; He, Siyuan

    2012-09-01

    This paper reports a standing wave brass-PZT tubular ultrasonic motor. The motor is composed of a brass square tube with two teeth on each tube end. Four PZT plates are attached to the outside walls of the brass tube. The motor requires only one driving signal to excite vibration in a single bending mode to generate reciprocating diagonal trajectories of teeth on the brass tube ends, which drive the motor to rotate. Bi-directional rotation is achieved by exciting different pairs of PZT plates to switch the bending vibration direction. Through using the brass-PZT tube structure, the motor can take high magnitude vibration to achieve a high output power in comparison to PZT tube based ultrasonic motors. Prototypes are fabricated and tested. The dimension of the brass-PZT tube is 3.975mm×3.975mm×16mm. Measured performance is a no-load speed of >1000RPM, a stall torque of 370μNm and a maximum output power of 16 mW when a sinusoidal driving voltage of 50V is applied. The working frequencies of the motor are 46,050Hz (clockwise) and 46,200Hz (counter-clockwise). Copyright © 2012. Published by Elsevier B.V.

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

    Science.gov (United States)

    Si, Jikai; Feng, Haichao; Su, Peng; Zhang, Lufeng

    2014-01-01

    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. PMID:25050388

  16. Quantitation of renal function with glomerular and tubular agents

    International Nuclear Information System (INIS)

    Dubovsky, E.V.; Russell, C.D.

    1982-01-01

    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

  17. HIGH-TEMPERATURE TUBULAR SOLID OXIDE FUEL CELL GENERATOR DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    S.E. Veyo

    1998-09-01

    During the Westinghouse/USDOE Cooperative Agreement period of November 1, 1990 through November 30, 1997, the Westinghouse solid oxide fuel cell has evolved from a 16 mm diameter, 50 cm length cell with a peak power of 1.27 watts/cm to the 22 mm diameter, 150 cm length dimensions of today's commercial prototype cell with a peak power of 1.40 watts/cm. Accompanying the increase in size and power density was the elimination of an expensive EVD step in the manufacturing process. Demonstrated performance of Westinghouse's tubular SOFC includes a lifetime cell test which ran for a period in excess of 69,000 hours, and a fully integrated 25 kWe-class system field test which operated for over 13,000 hours at 90% availability with less than 2% performance degradation over the entire period. Concluding the agreement period, a 100 kW SOFC system successfully passed its factory acceptance test in October 1997 and was delivered in November to its demonstration site in Westervoort, The Netherlands.

  18. Statistical tracking of tree-like tubular structures with efficient branching detection in 3D medical image data

    International Nuclear Information System (INIS)

    Wang, X; Heimann, T; Meinzer, H P; Wegner, I; Lo, P; Sumkauskaite, M; Puderbach, M; De Bruijne, M

    2012-01-01

    The segmentation of tree-like tubular structures such as coronary arteries and airways is an essential step for many 3D medical imaging applications. Statistical tracking techniques for the extraction of elongated structures have received considerable attention in recent years due to their robustness against image noise and pathological changes. However, most tracking methods are limited to a specific application and do not support branching structures efficiently. In this work, we present a novel statistical tracking approach for the extraction of different types of tubular structures with ringlike cross-sections. Domain-specific knowledge is learned from training data sets and integrated into the tracking process by simple adaption of parameters. In addition, an efficient branching detection algorithm is presented. This approach was evaluated by extracting coronary arteries from 32 CTA data sets and distal airways from 20 CT scans. These data sets were provided by the organizers of the workshop ‘3D Segmentation in the Clinic: A Grand Challenge II-Coronary Artery Tracking (CAT08)’ and ‘Extraction of Airways from CT 2009 (EXACT’09)’. On average, 81.5% overlap and 0.51 mm accuracy for the tracking of coronary arteries were achieved. For the extraction of airway trees, 51.3% of the total tree length, 53.6% of the total number of branches and a 4.98% false positive rate were attained. In both experiments, our approach is comparable to state-of-the-art methods. (paper)

  19. Reclamation of grey water for non-potable purposes using pilot-scale solar photocatalytic tubular reactors.

    Science.gov (United States)

    Saran, Sarangapany; Arunkumar, Patchaiyappan; Manjari, Gangarapu; Devipriya, Suja P

    2018-05-05

    Application of pilot-scale slurry-type tubular photocatalytic reactor was tested for the decentralized treatment of actual grey water. The reactors were fabricated by reusing the locally available materials at low cost, operated in batch recycle mode with 25 L of grey water. The influence of operational parameters such as catalysts' concentration, initial slurry pH and addition of H 2 O 2 on COD abatement were optimized. The results show that Ag-decorated TiO 2 showed a two-fold increase in COD abatement than did pure TiO 2 . Better COD abatement was observed under acidic conditions, and addition of H 2 O 2 significantly increases the rate of COD abatement. Within 2 h, 99% COD abatement was observed when the reactor was operated with optimum operational conditions. Silver ion lixiviate was also monitored during the experiment and is five times less than the permissible limits. The catalyst shows good stability even after five cycles without much loss in its photocatalytic activity. The results clearly reveal that pilot-scale slurry tubular solar photocatalytic reactors could be used as a cost-effective method to treat grey water and the resulting clean water could be reused for various non-potable purposes, thus conserving precious water resource. This study favours decentralized grey water treatment and possible scaling up of solar photocatalytic reactor using locally available materials for the potential reuse of treated water.

  20. Relationship between changes in hemoglobin glycosilated and improvement of body composition in patients with morbid obesity after tubular laparoscopic gastrectomy.

    Science.gov (United States)

    Gallart-Aragón, Tania; Fernández-Lao, Carolina; Cózar-Ibañez, Antonio; Cantarero-Villanueva, Irene; Cambil-Martín, Jacobo; Jiménez Ríos, José Antonio; Arroyo-Morales, Manuel

    2017-12-29

    The objective of our study is to analyze the possible relationship between changes in glycemic profile and body composition parameters in morbid obesity patients after tubular laparoscopic gastrectomy. A prospective observational cohort study with 69 patients was performed. The variables analyzed were body weight, blood glucose, hemoglobin, glycosylated, high density lipoprotein, low density lipoprotein, triglycerides, and waist and hip circumference. An analysis of variance of repeated measurements (ANOVA) and a correlation analysis through the Pearson test were carried out. A significant reduction in weight (p<.001 after surgery) and in glycosylated hemoglobin (p<.036) and waist hip (p<.001) were found at 6 months after surgery. There was no significant difference in the rest of the variables studied. In correlation analysis, a significant positive correlation was found between the change in concentration of hemoglobin glycosylated and hip circumference (p=.047; r=0.237), the smaller the hip circumference, the lower the concentration of glycosylated hemoglobin. Tubular laparoscopic gastrectomy is an effective technique for the treatment of morbidly obese patients with type 2 diabetes mellitus. The reduction in the perimeter of hip is related to glycosylated hemoglobin reduction 6 months after intervention. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  1. Effect of cisplatin on renal haemodynamics and tubular function in the dog kidney

    DEFF Research Database (Denmark)

    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 cap...... capacities associated with increased renal vascular resistance. The polyuria seems to be due to the impaired reabsorption rate in the distal nephron segments....

  2. Facile Fabrication of Uniform Polyaniline Nanotubes with Tubular Aluminosilicates as Templates

    OpenAIRE

    Zhang, Long; Liu, Peng

    2008-01-01

    AbstractThe 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 conduct...

  3. Renal tubular dysfunction presenting as recurrent hypokalemic periodic quadriparesis in systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    D Prasad

    2014-01-01

    Full Text Available We report recurrent hypokalemic periodic quadriparesis in a 30-year-old woman. Patient had also symptoms of multiple large and small joint pain, recurrent oral ulceration, photosensitivity and hair loss that were persisting since last 6 months and investigations revealed systemic lupus erythematosus (SLE with distal tubular acidosis. Our patient was successfully treated with oral potassium chloride, sodium bicarbonate, hydroxychloroquine and a short course of steroids. Thus, tubular dysfunction should be carefully assessed in patients with SLE.

  4. Hypokalaemia and Renal Tubular Acidosis due to Abuse of Nurofen Plus

    Directory of Open Access Journals (Sweden)

    M. J. Blackstock

    2012-01-01

    Full Text Available Nurofen Plus is a common analgesic containing ibuprofen and codeine. We present a case of a 38-year-old lady who developed renal tubular acidosis with severe hypokalaemia, after chronic abuse of Nurofen Plus tablets. She presented with confusion and profound biochemical abnormalities requiring critical care admission for electrolyte replacement. Ibuprofen causes renal tubular acidosis due to its effects on carbonic anhydrase activity.

  5. Ground Vibration Isolation of Multiple Scattering by Using Rows of Tubular Piles as Barriers

    Directory of Open Access Journals (Sweden)

    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.

  6. The effect of acyclovir on the tubular secretion of creatinine in vitro

    Directory of Open Access Journals (Sweden)

    Aleksa Katarina

    2010-12-01

    Full Text Available Abstract Background While generally well tolerated, severe nephrotoxicity has been observed in some children receiving acyclovir. A pronounced elevation in plasma creatinine in the absence of other clinical manifestations of overt nephrotoxicity has been frequently documented. Several drugs have been shown to increase plasma creatinine by inhibiting its renal tubular secretion rather than by decreasing glomerular filtration rate (GFR. Creatinine and acyclovir may be transported by similar tubular transport mechanisms, thus, it is plausible that in some cases, the observed increase in plasma creatinine may be partially due to inhibition of tubular secretion of creatinine, and not solely due to decreased GFR. Our objective was to determine whether acyclovir inhibits the tubular secretion of creatinine. Methods Porcine (LLC-PK1 and human (HK-2 renal proximal tubular cell monolayers cultured on microporous membrane filters were exposed to [2-14C] creatinine (5 μM in the absence or presence of quinidine (1E+03 μM, cimetidine (1E+03 μM or acyclovir (22 - 89 μM in incubation medium. Results Results illustrated that in evident contrast to quinidine, acyclovir did not inhibit creatinine transport in LLC-PK1 and HK-2 cell monolayers. Conclusions The results suggest that acyclovir does not affect the renal tubular handling of creatinine, and hence, the pronounced, transient increase in plasma creatinine is due to decreased GFR, and not to a spurious increase in plasma creatinine.

  7. Inner Surface Chirality of Single-Handed Twisted Carbonaceous Tubular Nanoribbons.

    Science.gov (United States)

    Liu, Dan; Li, Baozong; Guo, Yongmin; Li, Yi; Yang, Yonggang

    2015-11-01

    Single-handed twisted 4,4'-biphenylene-bridged polybissilsesquioxane tubular nanoribbons and single-layered nanoribbons were prepared by tuning the water/ethanol volume ratio in the reaction mixture at pH = 11.6 through a supramolecular templating approach. The single-layered nanoribbons were formed by shrinking tubular nanoribbons after the removal of the templates. In addition, solvent-induced handedness inversion was achieved. The handedness of the polybissilsesquioxanes could be controlled by changing the ethanol/water volume ratio in the reaction mixture. After carbonization at 900 °C for 4.0 h and removal of silica, single-handed twisted carbonaceous tubular nanoribbons and single-layered nanoribbons with micropores in the walls were obtained. X-ray diffraction and Raman spectroscopy analyses indicated that the carbon is predominantly amorphous. The circular dichroism spectra show that the twisted tubular nanoribbons exhibit optical activity, while the twisted single-layered nanoribbons do not. The results shown here indicate that chirality is transferred from the organic self-assemblies to the inner surfaces of the 4,4'-biphenylene-bridged polybissilsesquioxane tubular nanoribbons and subsequently to those of the carbonaceous tubular nanoribbons. © 2015 Wiley Periodicals, Inc.

  8. Prevalence of renal tubular dysfunction in beta thalassemia minor in shiraz

    Directory of Open Access Journals (Sweden)

    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. pH measurement of tubular vacuoles of an arbuscular mycorrhizal fungus, Gigaspora margarita.

    Science.gov (United States)

    Funamoto, Rintaro; Saito, Katsuharu; Oyaizu, Hiroshi; Aono, Toshihiro; Saito, Masanori

    2015-01-01

    Arbuscular mycorrhizal fungi play an important role in phosphate supply to the host plants. The fungal hyphae contain tubular vacuoles where phosphate compounds such as polyphosphate are accumulated. Despite their importance for the phosphate storage, little is known about the physiological properties of the tubular vacuoles in arbuscular mycorrhizal fungi. As an indicator of the physiological state in vacuoles, we measured pH of tubular vacuoles in living hyphae of arbuscular mycorrhizal fungus Gigaspora margarita using ratio image analysis with pH-dependent fluorescent probe, 6-carboxyfluorescein. Fluorescent images of the fine tubular vacuoles were obtained using a laser scanning confocal microscope, which enabled calculation of vacuolar pH with high spatial resolution. The tubular vacuoles showed mean pH of 5.6 and a pH range of 5.1-6.3. These results suggest that the tubular vacuoles of arbuscular mycorrhizal fungi have a mildly acidic pH just like vacuoles of other fungal species including yeast and ectomycorrhizal fungi.

  10. Review: peripheral nerve regeneration using non-tubular alginate gel crosslinked with covalent bonds.

    Science.gov (United States)

    Hashimoto, Tadashi; Suzuki, Yoshihisa; Suzuki, Kyoko; Nakashima, Toshihide; Tanihara, Masao; Ide, Chizuka

    2005-06-01

    We have developed a nerve regeneration material consisting of alginate gel crosslinked with covalent bonds. in the first part of this study, we attempted to analyze nerve regeneration through alginate gel in the early stages within 2 weeks. in the second part, we tried to regenerate cat peripheral nerve by using alginate tubular or non-tubular nerve regeneration devices, and compared their efficacies. Four days after surgery, regenerating axons grew without Schwann cell investment through the partially degraded alginate gel, being in direct contact with the alginate without a basal lamina covering. One to 2 weeks after surgery, regenerating axons were surrounded by common Schwann cells, forming small bundles, with some axons at the periphery being partly in direct contact with alginate. At the distal stump, numerous Schwann cells had migrated into the alginate 8-14 days after surgery. Remarkable restorations of the 50-mm gap in cat sciatic nerve were obtained after a long term by using tubular or non-tubular nerve regeneration material consisting mainly of alginate gel. However, there was no significant difference between both groups at electrophysiological and morphological evaluation. Although, nowadays, nerve regeneration materials being marketed mostly have a tubular structure, our results suggest that the tubular structure is not indispensable for peripheral nerve regeneration.

  11. Hyperammonemia associated with distal renal tubular acidosis or urinary tract infection: a systematic review.

    Science.gov (United States)

    Clericetti, Caterina M; Milani, Gregorio P; Lava, Sebastiano A G; Bianchetti, Mario G; Simonetti, Giacomo D; Giannini, Olivier

    2018-03-01

    Hyperammonemia usually results from an inborn error of metabolism or from an advanced liver disease. Individual case reports suggest that both distal renal tubular acidosis and urinary tract infection may also result in hyperammonemia. A systematic review of the literature on hyperammonemia secondary to distal renal tubular acidosis and urinary tract infection was conducted. We identified 39 reports on distal renal tubular acidosis or urinary tract infections in association with hyperammonemia published between 1980 and 2017. Hyperammonemia was detected in 13 children with distal renal tubular acidosis and in one adult patient with distal renal tubular acidosis secondary to primary hyperparathyroidism. In these patients a negative relationship was observed between circulating ammonia and bicarbonate levels (P urinary tract infection was complicated by acute hyperammonemia and symptoms and signs of acute neuronal dysfunction, such as an altered level of consciousness, convulsions and asterixis, often associated with signs of brain edema, such as anorexia and vomiting. Urea-splitting bacteria were isolated in 28 of the 31 cases. The urinary tract was anatomically or functionally abnormal in 30 of these patients. This study reveals that both altered distal renal tubular acidification and urinary tract infection may be associated with relevant hyperammonemia in both children and adults.

  12. Study of technological features of tubular compressed concrete members in concreting

    Directory of Open Access Journals (Sweden)

    Voskobiinyk Olena

    2017-01-01

    Full Text Available The technological features of core concreting were analyzed as the main factor in ensuring of strength and reliability of compressed concrete-filled steel tubular (CFST members. We have conducted the analysis of existing concreting methods of CFST members. In this respect, the most dangerous types of possible technological defects of concrete core of CFST members are inhomogeneity along the height, voids, caverns, and concrete “weak spots”. The authors considered the influence of such technological factors of concreting: placeability, time, concrete mixture compaction method, concreting height on the concrete core strength of CFST members. Based on the experimental studies conducted we suggested the regression correlations for determining the concrete strength of CFST members of different length depending on the movability of concrete mixture and a time for its compaction. The authors performed the correlation analysis of technological factors of concreting on the strength of the concrete core. We carried out the comparison of data on the concrete core strength of CFST members, that were determined by non-destructive methods (sclerometer test results, ultrasonic method and direct compression strength tests. We experimentally proved that using movable mixtures with the slump of about 4 – 9 cm the overall variation coefficient of concrete core strength of CFST members along the height reaches nearly 13%. Based on the experimental studies conducted we suggested the guidelines on optimal regimes of concrete compaction during manufacturing CFST members at a construction site environment.

  13. Charge movements and transverse tubular ultrastructure in organ cultured skeletal muscle.

    Science.gov (United States)

    Cullen, M J; Hollingworth, S; Marshall, M W; Robson, E

    1990-04-01

    A study was made of charge movements and the transverse tubular systems in rat EDL and soleus muscle fibres maintained for up to five days in organ culture. In the cultured EDL muscle the maximum amount of charge moved was about one third of that in innervated muscle. Charge movements in innervated soleus fibres are small, less than 10 nC/microF, and difficult to resolve. They remain small following organ culturing. The ultrastructural study examined the concentration of junctional feet because of their proposed key role in excitation-contraction coupling. The general architecture of the triads and the spacing of the feet in both muscle types was largely unchanged by culturing. In cultured EDL muscles the small changes in feet concentration did not parallel the large fall in charge movement. The results reported here support a previous conclusion that, in mammalian muscle, there is not a simple relation between charge and feet. The stimulation of cultured soleus muscles with a fast twitch pattern of electrical activity produced no observable changes in morphology.

  14. Catalytic Oxidation of Vanillyl Alcohol Using FeMCM-41 Nanoporous Tubular Reactor

    Science.gov (United States)

    Elamathi, P.; Kolli, Murali Krishna; Chandrasekar, G.

    Iron containing nanoporous MCM-41 (FeMCM-41) with different Si/Fe ratios of 50, 100 and 150 was synthesized by hydrothermal synthesis process. The materials obtained from hydrothermal synthesis were characterized by various physico chemical techniques such as XRD, N2 adsorption, DR UV-vis, EPR and FTIR spectroscopy. XRD analyses of FeMCM-41 materials confirmed the presence of well-ordered crystalline structure. N2 isotherm of FeMCM-41 materials showed type IV adsorption isotherm. EPR and DR UV-vis analysis of FeMCM-41 samples indicates the presence of high tetrahedral coordination at the Si/Fe ratios of 100 and 150. The catalytic performance of FeMCM-41 nano tubular reactor was tested in the liquid phase oxidation of vanillyl alcohol into vanillin using H2O2 (50wt% in water). The reaction products were analyzed by gas chromatography in DB-5 capillary column with flame ionization detector. The products were confirmed by 1H NMR, 13C NMR and LC-Mass spectroscopy. The maximum conversion of vanillyl alcohol (85%) and selectivity towards vanillin (82%) were observed using the catalyst FeMCM-41(100) in 30min at 60∘C. The influence of reaction temperature, reaction time, reactants molar ratio, Si/Fe ratio and amount of catalyst were investigated.

  15. Preliminary experiments of a tubular linear actuator in the vertical direction using YBCO bulk

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, A; Ueda, H; Ishiyama, A [Department of Electrical Engineering and Bioscience, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2004-05-01

    We have been developing a new type of active-maglev system composed of field-cooled disc-shaped YBCO bulk and multiple ring-shaped electromagnets, which are vertically piled up. One of the useful features of the active-maglev system is that the levitation height is adjustable by varying the operating current through an electromagnet. Maximum levitation height in stable levitation, however, is restricted by the magnetic field distribution produced by the electromagnet. To enhance the levitation height, we have fabricated and tested an active-maglev system with multiple ring-shaped electromagnets instead of using a larger single electromagnet. Up to now, we have reported the experimental results in a model active-maglev system composed of five electromagnets and showed that the levitation height, as well as stability, can be remarkably improved by adjusting the operating current of each electromagnet individually. In this study, we constructed a model system operated as a tubular linear synchronous actuator in the vertical direction in expectation of it being applied in factory automation upgrading. The primary consists of six ring-shaped copper-winding coils without iron core and is supplied with three-phase sinusoidal excitation. A disc-shaped YBCO bulk, which was magnetized by a field-cooling process, was adopted as a secondary (mover). We carried out preliminary experiments to confirm the feasibility of synchronous operation and also numerically investigated the electromagnetic phenomenon within the bulk superconductor by a developed computer program based on the finite element method.

  16. Preliminary experiments of a tubular linear actuator in the vertical direction using YBCO bulk

    International Nuclear Information System (INIS)

    Sugawara, A; Ueda, H; Ishiyama, A

    2004-01-01

    We have been developing a new type of active-maglev system composed of field-cooled disc-shaped YBCO bulk and multiple ring-shaped electromagnets, which are vertically piled up. One of the useful features of the active-maglev system is that the levitation height is adjustable by varying the operating current through an electromagnet. Maximum levitation height in stable levitation, however, is restricted by the magnetic field distribution produced by the electromagnet. To enhance the levitation height, we have fabricated and tested an active-maglev system with multiple ring-shaped electromagnets instead of using a larger single electromagnet. Up to now, we have reported the experimental results in a model active-maglev system composed of five electromagnets and showed that the levitation height, as well as stability, can be remarkably improved by adjusting the operating current of each electromagnet individually. In this study, we constructed a model system operated as a tubular linear synchronous actuator in the vertical direction in expectation of it being applied in factory automation upgrading. The primary consists of six ring-shaped copper-winding coils without iron core and is supplied with three-phase sinusoidal excitation. A disc-shaped YBCO bulk, which was magnetized by a field-cooling process, was adopted as a secondary (mover). We carried out preliminary experiments to confirm the feasibility of synchronous operation and also numerically investigated the electromagnetic phenomenon within the bulk superconductor by a developed computer program based on the finite element method

  17. Removal of chromium from synthetic wastewater using MFI zeolite membrane supported on inexpensive tubular ceramic substrate

    Directory of Open Access Journals (Sweden)

    R. Vinoth Kumar

    2017-09-01

    Full Text Available A mordenite framework inverted (MFI type zeolite membrane was produced on inexpensive tubular ceramic substrate through hydrothermal synthesis and applied for the removal of chromium from synthetic wastewater. The fabricated ceramic substrate and membrane was characterized by diverse standard techniques such as X-ray diffraction, field emission scanning electron microscope, porosity, water permeability and pore size measurements. The porosity of the ceramic substrate (53% was reduced by the deposition of MFI (51% zeolite layer. The pore size and water permeability of the membrane was evaluated as 0.272 μm and 4.43 × 10–7 m3/m2s.kPa, respectively, which are lower than that of the substrate pore size (0.309 μm and water permeability (5.93 × 10–7 m3/m2s.kPa values. To identify the effectiveness of the prepared membrane, the applied pressure of the filtration process and initial chromium concentration and cross flow rate were varied to study their influence on the permeate flux and percentage of removal. The maximum removal of chromium achieved was 78% under an applied pressure of 345 kPa and an initial feed concentration of 1,000 ppm. Finally, the efficiency of the membrane for chromium removal was assessed with other membranes reported in the literature.

  18. Nanoparticulate Tubular Immunostimulating Complexes: Novel Formulation of Effective Adjuvants and Antigen Delivery Systems

    Directory of Open Access Journals (Sweden)

    Nina Sanina

    2017-01-01

    Full Text Available New generation vaccines, based on isolated antigens, are safer than traditional ones, comprising the whole pathogen. However, major part of purified antigens has weak immunogenicity. Therefore, elaboration of new adjuvants, more effective and safe, is an urgent problem of vaccinology. Tubular immunostimulating complexes (TI-complexes are a new type of nanoparticulate antigen delivery systems with adjuvant activity. TI-complexes consist of cholesterol and compounds isolated from marine hydrobionts: cucumarioside A2-2 (CDA from Cucumaria japonica and monogalactosyldiacylglycerol (MGDG from marine algae or seagrass. These components were selected due to immunomodulatory and other biological activities. Glycolipid MGDG from marine macrophytes comprises a high level of polyunsaturated fatty acids (PUFAs, which demonstrate immunomodulatory properties. CDA is a well-characterized individual compound capable of forming stable complex with cholesterol. Such complexes do not possess hemolytic activity. Ultralow doses of cucumariosides stimulate cell as well as humoral immunity. Therefore, TI-complexes comprising biologically active components turned out to be more effective than the strongest adjuvants: immunostimulating complexes (ISCOMs and complete Freund’s adjuvant. In the present review, we discuss results published in series of our articles on elaboration, qualitative and quantitative composition, ultrastructure, and immunostimulating activity of TI-complexes. The review allows immersion in the history of creating TI-complexes.

  19. Liquid sensing capability of rolled-up tubular optical microcavities: a theoretical study.

    Science.gov (United States)

    Zhao, Fangyuan; Zhan, Tianrong; Huang, Gaoshan; Mei, Yongfeng; Hu, Xinhua

    2012-10-07

    Rolled-up tubular optical microcavities are a novel type of optical sensor for identifying different liquids and monitoring single cells. Based on a Mie scattering method, we systematically study the optical resonances and liquid sensing capability of microtubes. Analytical formulas are presented to calculate the resonant wavelengths λ(r), Q factors, sensitivities S and figures of merit QS. Both ideal and rolled-up microtubes are considered for different optical materials in tube walls (refractive indices ranging from 1.5 to 2.5) and for three setups: tube-in-liquid, hollow-tube-in-liquid and liquid-in-tube. It is found that for rolled-up microtubes, the highest QS can be achieved by using the liquid-in-tube setup and very thin wall thicknesses. A maximal sensitivity is found in the case of the liquid cylinder. Our theory well explains a recent experiment under the setup of tube-in-liquid. It is also found that, although it describes the case of tube-in-liquid well, the waveguide approximation approach is not suitable for the case of liquid-in-tube. The results could be useful to design better optofluidic devices based on rolled-up microtubes.

  20. BAG3 regulates ECM accumulation in renal proximal tubular cells induced by TGF-β1.

    Science.gov (United States)

    Du, Feng; Li, Si; Wang, Tian; Zhang, Hai-Yan; Li, De-Tian; Du, Zhen-Xian; Wang, Hua-Qin; Wang, Yan-Qiu

    2015-01-01

    Previously we have demonstrated that Bcl-2-associated athanogene 3 (BAG3) is increased in renal fibrosis using a rat unilateral ureteral obstruction model. The current study investigated the role of BAG3 in renal fibrosis using transforming growth factor (TGF)-β1-treated human proximal tubular epithelial (HK-2) cells. An upregulation of BAG3 in vitro models was observed, which correlated with the increased synthesis of extracellular matrix (ECM) proteins and expression of tissue-type plasminogen activator inhibitor (PAI)-1. Blockade of BAG3 induction by shorting hairpin RNA suppressed the expression of ECM proteins but had no effect on PAI-1 expression induced by TGF-β1. Forced overexpression of BAG3 selectively increased collagens. TGF-β1-induced BAG3 expression in HK-2 cells was attenuated by ERK1/2 and JNK MAPK inhibitors. In addition, forced BAG3 overexpression blocked attenuation of collagens expression by ERK1/2 and JNK inhibitors. These data suggest that ERK1/2 and JNK signaling events are involved in modulating the expression of BAG3, which would ultimately contribute to renal fibrosis by enhancing the synthesis and deposition of ECM proteins.

  1. Critical heat fluxes in tubular fuel elements of nuclear power reactors

    International Nuclear Information System (INIS)

    Subbotin, V.I.; Alekseev, G.V.; Peskov, O.L.

    1974-01-01

    The results of the experiments carried out show that with appropriate choice of tube, type and dimensions of intensifier the attainment of critical conditions at certain parameters is not accompanied by sharp or considerable increases in temperature of the heat removing surface. Increase in power to above critical under these conditions does not lead to considerable variation in temperature either. Thus, it appears possible to change from heat removal by steam-water mixture to convective heat removal by wet steam without manifestation of intolerable temperature conditions of the heating surface (Fig. 6). A change to convective heat removal by wet steam is possible at different levels of heat fluxes which depend during constant conditions at the inlet on tube length and the degree of the disturbing influence on the flow. This is especially important since in principle the possibility arises for developing a power reactor with tubular fuel elements, in which a once-through cycle with steam superheat involving no intermediate separation can be realised

  2. Design, construction and evaluation of solarized airlift tubular photobioreactor

    International Nuclear Information System (INIS)

    Bahadur, A; Zubair, M; Khan, M B

    2013-01-01

    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/m 2 .day) as compared to theoretical modeled yield of 0.82 g/l.day (14.26 g/m 2 .day), suggesting the device can be efficiently and cost-effectively employed in the production of algal biomass for biofuels, concomitantly mitigating CO 2 .

  3. Effect of air flow on tubular solar still efficiency.

    Science.gov (United States)

    Thirugnanasambantham, Arunkumar; Rajan, Jayaprakash; Ahsan, Amimul; Kandasamy, Vinothkumar

    2013-01-01

    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. 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.

  4. Relating porosity and mechanical properties in spray formed tubulars

    International Nuclear Information System (INIS)

    Payne, R.D.; Naval Surface Warfare Center, Annapolis, MD; Moran, A.L.; United States Naval Academy, Annapolis, MD; Cammarata, R.C.

    1993-01-01

    Because the spray forming process holds the potential to reduce the cost of alloy production, there is significant interest in developing methods to industrialized and automate this process through advanced sensing techniques. These advanced sensing techniques will observe the process real-time and give inputs to a process controller. By determining relationships between part quality, process parameters and sensor inputs, the process controller will be able to determine the quality of a part while it is being made and make adjustments if necessary. A Tinius-Olsen Tensile Tester was used to test five tensile specimens. The five tensile specimens were taken from five alloy 625 (60% Ni, 20% Cr, 8%Mo, 5% Fe) tubulars with varying properties. Among the advanced sensing techniques currently used to monitor the spray forming process is a surface roughness sensor. It consists of an argon laser, a charge coupled device (CCD) camera and roughness determination software. The laser emission is expanded into a long, thin line and projected onto the substrate as the molten metal consolidates on the surface. The roughness determination software will grab a frame with the laser stripe, digitize it and calculate the root mean square (RMS) value of the roughness in that particular frame. Each frame has a time stamp and can be related back to other time stamped process parameters. Recent sensor work has tried to find correlations between RMS values and porosities determined after processing. This venture has met with limited success. The object of this paper is to link porosity with mechanical properties and therefore define quality. Eventually the input from all sensors and process parameters will be entered into a process controller. If there is a link between sensor data and quality, this controller will be able to determine the quality of a forming material from sensor inputs and make changes in the process parameters if the quality is poor

  5. Analysis of a 3-phase tubular permanent magnet linear generator

    Energy Technology Data Exchange (ETDEWEB)

    Nor, K.M.; Arof, H.; Wijono [Malaya Univ., Kuala Lumpur (Malaysia). Faculty of Engineering

    2005-07-01

    A 3-phase tubular permanent linear generator design was described. The generator was designed to be driven by a single or a double 2-stroke combustion linear engine. Combustion took place alternately between 2 opposed chambers. In the single combustion engine, one of the combustion chambers was replaced by a kickback mechanism. The force on the translator generated by the explosion in the combustion chamber was used to compress the air in the kickback chamber. The pressed air was then used to release the stored energy to push back the translator in the opposite direction. The generator was modelled as a 2D object. A parametric simulation was performed to give a series of discrete data required to calculate machine electrical parameters; flux distribution; coil flux linkage; and, cogging force. Fringing flux was evaluated through the application of a magnetic boundary condition. The infinity boundary was used to include the zero electromagnetic potential in the surface boundary. A complete simulation was run for each step of the translator's motion, which was considered as sinusoidal. The simplification was further corrected using the real engine speed curve. The EMF was derived from the flux linkage difference in the coils at every consecutive translator position. Force was calculated in the translator and stator using a virtual work method. Optimization was performed using a subproblem strategy. It was concluded that the generator can be used to supply electric power as a stand-alone system, emergency power supply, or as part of an integrated system. 11 refs., 2 tabs., 10 figs.

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

    Directory of Open Access Journals (Sweden)

    Frances E. Jones

    2016-02-01

    Full Text Available 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.

  7. Urinary excretion of beta 2-glycoprotein-1 (apolipoprotein H) and other markers of tubular malfunction in "non-tubular" renal disease.

    Science.gov (United States)

    Flynn, F V; Lapsley, M; Sansom, P A; Cohen, S L

    1992-07-01

    To determine whether urinary beta 2-glycoprotein-1 assays can provide improved discrimination between chronic renal diseases which are primarily of tubular or glomerular origin. Urinary beta 2-glycoprotein-1, retinol-binding protein, alpha 1-microglobulin, beta 2-microglobulin, N-acetyl-beta-D-glucosa-minidase and albumin were measured in 51 patients with primary glomerular disease, 23 with obstructive nephropathy, and 15 with polycystic kidney disease, and expressed per mmol of creatinine. Plasma beta 2-glycoprotein-1 was assayed in 52 patients and plasma creatinine in all 89. The findings were compared between the diagnostic groups and with previously published data relating to primary tubular disorders. All 31 patients with plasma creatinine greater than 200 mumol/l excreted increased amounts of beta 2-glycoprotein-1, retinol-binding protein, and alpha 1-microglobulin, and 29 had increased N-acetyl-beta-D-glucosaminidase; the quantities were generally similar to those found in comparable patients with primary tubular pathology. Among 58 with plasma creatinine concentrations under 200 mumol/l, increases in beta 2-glycoprotein-1, retinol-binding protein, and alpha 1-microglobulin excretion were less common and much smaller, especially in those with obstructive nephropathy and polycystic disease. The ratios of the excretion of albumin to the other proteins provided the clearest discrimination between the patients with glomerular or tubular malfunction, but an area of overlap was present which embraced those with obstructive nephropathy and polycystic disease. Increased excretion of beta 2-glycoprotein-1 due to a raised plasma concentration or diminution of tubular reabsorption, or both, is common in all the forms of renal disease investigated, and both plasma creatinine and urinary albumin must be taken into account when interpreting results. Ratios of urinary albumin: beta 2-glycoprotein-1 greater than 1000 are highly suggestive of primary glomerular disease and

  8. Novel insights on the relationship between T-tubular defects and contractile dysfunction in a mouse model of hypertrophic cardiomyopathy.

    Science.gov (United States)

    Crocini, C; Ferrantini, C; Scardigli, M; Coppini, R; Mazzoni, L; Lazzeri, E; Pioner, J M; Scellini, B; Guo, A; Song, L S; Yan, P; Loew, L M; Tardiff, J; Tesi, C; Vanzi, F; Cerbai, E; Pavone, F S; Sacconi, L; Poggesi, C

    2016-02-01

    Abnormalities of cardiomyocyte Ca(2+) homeostasis and excitation-contraction (E-C) coupling are early events in the pathogenesis of hypertrophic cardiomyopathy (HCM) and concomitant determinants of the diastolic dysfunction and arrhythmias typical of the disease. T-tubule remodelling has been reported to occur in HCM but little is known about its role in the E-C coupling alterations of HCM. Here, the role of T-tubule remodelling in the electro-mechanical dysfunction associated to HCM is investigated in the Δ160E cTnT mouse model that expresses a clinically-relevant HCM mutation. Contractile function of intact ventricular trabeculae is assessed in Δ160E mice and wild-type siblings. As compared with wild-type, Δ160E trabeculae show prolonged kinetics of force development and relaxation, blunted force-frequency response with reduced active tension at high stimulation frequency, and increased occurrence of spontaneous contractions. Consistently, prolonged Ca(2+) transient in terms of rise and duration are also observed in Δ160E trabeculae and isolated cardiomyocytes. Confocal imaging in cells isolated from Δ160E mice reveals significant, though modest, remodelling of T-tubular architecture. A two-photon random access microscope is employed to dissect the spatio-temporal relationship between T-tubular electrical activity and local Ca(2+) release in isolated cardiomyocytes. In Δ160E cardiomyocytes, a significant number of T-tubules (>20%) fails to propagate action potentials, with consequent delay of local Ca(2+) release. At variance with wild-type, we also observe significantly increased variability of local Ca(2+) transient rise as well as higher Ca(2+)-spark frequency. Although T-tubule structural remodelling in Δ160E myocytes is modest, T-tubule functional defects determine non-homogeneous Ca(2+) release and delayed myofilament activation that significantly contribute to mechanical dysfunction. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All

  9. Microstructure and mechanical properties of AZ91 tubes fabricated by Multi-pass Parallel Tubular Channel Angular Pressing

    OpenAIRE

    Hooman Abdolvand; Ghader Faraji; Javad Shahbazi Karami

    2017-01-01

    Parallel Tubular Channel Angular Pressing (PTCAP) process is a novel recently developed severe plastic deformation (SPD) method for producing ultrafine grained (UFG) and nanograined (NG) tubular specimens with excellent mechanical and physical properties. This process has several advantageous compared to its TCAP counterparts. In this paper, a fine grained AZ91 tube was fabricated via multi pass parallel tubular channel angular pressing (PTCAP) process. Tubes were processed up to three passes...

  10. Support and tool displacement device for the attachment of a tube bundle on a tubular plate of a steam generator

    International Nuclear Information System (INIS)

    Morisot, M.; Werle, R.; Michaud, J.P.

    1983-01-01

    The steam generator is being assembled, disposed with its axis horizontal and its tubular plate vertical; the device described in this patent, allows to automatize the preparation stages of the tubular plate and the attachment of the bundle, to shorten the construction of the steam generator and to remove drudgeries done by hand on the tubular plate or the tubes of the bundle. The invention can be applied to the construction of PWR steam generators [fr

  11. Statistical tracking of tree-like tubular structures with efficient branching detection in 3D medical image data

    DEFF Research Database (Denmark)

    Wang, X.; Heimann, T.; Lo, P.

    2012-01-01

    to their robustness against image noise and pathological changes. However, most tracking methods are limited to a specific application and do not support branching structures efficiently. In this work, we present a novel statistical tracking approach for the extraction of different types of tubular structures...... with ringlike cross-sections. Domain-specific knowledge is learned from training data sets and integrated into the tracking process by simple adaption of parameters. In addition, an efficient branching detection algorithm is presented. This approach was evaluated by extracting coronary arteries from 32 CTA data...... for the tracking of coronary arteries were achieved. For the extraction of airway trees, 51.3% of the total tree length, 53.6% of the total number of branches and a 4.98% false positive rate were attained. In both experiments, our approach is comparable to state-of-the-art methods....

  12. CT and MR imaging features of mucinous tubular and spindle cell carcinoma of the kidneys. A multi-institutional review

    Energy Technology Data Exchange (ETDEWEB)

    Cornelis, F.; Grenier, N. [Pellegrin Hospital, Department of Radiology, Bordeaux (France); Ambrosetti, D. [Pasteur Hospital, Department of Pathology, Nice (France); Rocher, L. [Kremlin-Bicetre Hospital, Department of Radiology, Paris (France); Derchi, L.E. [University of Genoa, IRCCS AOU Ospedale, San Martino IST, Department of Health Sciences (DISSAL), Genoa (Italy); Renard, B.; Puech, P. [Claude Huriez Hospital, Department of Radiology, Lille (France); Claudon, M. [Brabois Hospital, Department of Radiology, Vandoeuvre-les-Nancy (France); Rouviere, O. [E. Herriot Hospital, Department of Radiology, Lyon (France); Ferlicot, S. [Kremlin-Bicetre Hospital, Department of Pathology, Paris (France); Roy, C. [Civil Hospital, Department of Radiology, Strasbourg (France); Yacoub, M. [Pellegrin Hospital, Department of Pathology, Bordeaux (France); Bernhard, J.C. [Pellegrin Hospital, Department of Urologic Surgery, Bordeaux (France)

    2017-03-15

    Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney is a recently identified renal malignancy. Diagnosis of this rare subtype of renal tumour can be challenging for pathologists, and as such, any additional data would be helpful to improve diagnostic reliability. As imaging features of this new and rare sub-type have not yet been clearly described, the purpose of this study was to describe the main radiologic features on computed tomography (CT) and magnetic resonance imaging (MRI), based jointly on the literature and findings from a multi-institutional retrospective review of pathology and imaging databases. Using a combination of CT/MRI features, diagnosis of MTSCC could be suggested in many cases. A combination of slow enhancement with plateau on dynamic contrast-enhanced CT/MRI, intermediate to high T2 signal intensity contrasting with low apparent diffusion coefficient values on MRI appeared evocative of this diagnosis. (orig.)

  13. Osteomalacia complicating renal tubular acidosis in association with Sjogren's syndrome.

    Science.gov (United States)

    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.

  14. Amikacin-induced type 5 Bartter-like syndrome with severe hypocalcemia

    Directory of Open Access Journals (Sweden)

    Chrispal A

    2009-01-01

    Full Text Available Aminoglycoside-induced renal toxicity is well known and may manifest with nonoliguric renal failure or renal tubular dysfunction. Aminoglycoside-induced renal tubular dysfunction could result in diffuse damage or manifest as a Fanconi-like syndrome, Bartter-like syndrome, or distal renal tubular acidosis. We discuss a patient who developed severe renal tubular dysfunction secondary to short-term therapy with Amikacin, resulting in refractory hypokalemia, hypocalcemia, hypomagnesemia, metabolic alkalosis, and polyuria. This constellation of biochemical abnormalities mimic Type 5 Bartter′s syndrome, where there is activating mutation of the calcium sensing receptor in the thick ascending loop of Henle and the distal tubule. In this case this activation of the calcium sensing receptor was triggered by amikacin. This phenomenon has been described with gentamicin though never with amikacin. Recovery of the tubular dysfunction took 15 days following cessation of the offending drug, Amikacin.

  15. Tumor-promoting phorbol esters effect alkalinization of canine renal proximal tubular cells

    International Nuclear Information System (INIS)

    Mellas, J.; Hammerman, M.R.

    1986-01-01

    We have demonstrated the presence of specific receptors for tumor-promoting phorbol esters in the plasma membrane of the canine renal proximal tubular cell. These compounds affect proximal tubular metabolism in vitro. For example, we have shown that they inhibit gluconeogenesis in canine renal proximal tubular segments. Tumor-promoting phorbol esters have been shown to effect alkalinization of non-renal cells, by enhancing Na + -H + exchange across the plasma membrane. To determine whether the actions of tumor-promoting phorbol esters in proximal tubular segments might be mediated by a similar process, we incubated suspensions of segments from dog kidney with these compounds and measured changes in intracellular pH using [ 14 C]-5,5-dimethoxazoladine-2-4-dione (DMO) and flow dialysis. Incubation of segments with phorbol 12,13 dibutyrate, but not inactive phorbol ester, 4 γ phorbol, effected alkalinization of cells within the segments in a concentration-dependent manner. Alkalinization was dependent upon the presence of extracellular [Na + ] > intracellular [Na + ], was prevented by amiloride and was demonstrable in the presence of SITS. Our findings suggest that tumor-promoting esters stimulate the Na + -H + exchanger known to be present in the brush border membrane of the renal proximal tubular cell. It is possible that the stimulation reflects a mechanism by which phorbol esters affect metabolic processes in these cells

  16. Polydopamine-coated open tubular column for the separation of proteins by capillary electrochromatography.

    Science.gov (United States)

    Xiao, Xing; Wang, Wentao; Chen, Jia; Jia, Li

    2015-08-01

    The separation and determination of proteins in food is an important aspect in food industry. Inspired by the self-polymerization of dopamine under alkaline conditions and the natural adhesive properties of polydopamine, in this paper, a simple and economical method was developed for the preparation of polydopamine-coated open tubular column, in which ammonium persulfate was used as the source of oxygen to induce and facilitate the polymerization of dopamine to form polydopamine. In comparison with a naked fused-silica capillary, the direction and magnitude of the electro-osmotic flow of the as-prepared polydopamine-coated open tubular column could be manipulated by varying the pH values of background solutions due to the existence of amine and phenolic hydroxyl groups on polydopamine coating. The surface morphology of the polydopamine-coated open tubular column was studied by scanning electron microscopy, and the thickness of polydopamine coating was 106 nm. The performance of the polydopamine-coated open tubular column was validated by analysis of proteins. The relative standard deviations of migration times of proteins representing run-to-run, day-to-day, and column-to-column were less than 3.5%. In addition, the feasibility of the polydopamine-coated open tubular column for real samples was verified by the separation of proteins in chicken egg white and pure milk. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. The Tubular Penetration Depth and Adaption of Four Sealers: A Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Huan Chen

    2017-01-01

    Full Text Available Background. The tubular penetration and adaptation of the sealer are important factors for successful root canal filling. The aim of this study was to evaluate the tubular penetration depth of four different sealers in the coronal, middle, and apical third of root canals as well as the adaptation of these sealers to root canal walls. Materials and Methods. 50 single-rooted teeth were prepared in this study. Forty-eight of them were filled with different sealers (Cortisomol, iRoot SP, AH-Plus, and RealSeal SE and respective core filling materials. Then the specimens were sectioned and scanning electron microscopy was employed to assess the tubular penetration and adaptation of the sealers. Results. Our results demonstrated that the maximum penetration was exhibited by RealSeal SE, followed by AH-Plus, iRoot SP, and Cortisomol. As regards the adaptation property to root canal walls, AH-Plus has best adaptation capacity followed by iRoot SP, RealSeal SE, and Cortisomol. Conclusion. The tubular penetration and adaptation vary with the different sealers investigated. RealSeal SE showed the most optimal tubular penetration, whereas AH-Plus presented the best adaptation to the root canal walls.

  18. In vivo antibody-mediated modulation of aminopeptidase A in mouse proximal tubular epithelial cells.

    Science.gov (United States)

    Mentzel, S; Dijkman, H B; van Son, J P; Wetzels, J F; Assmann, K J

    1999-07-01

    Aminopeptidase A (APA) is one of the many renal hydrolases. In mouse kidney, APA is predominantly expressed on the brush borders and sparsely on the basolateral membranes of proximal tubular epithelial cells. However, when large amounts of monoclonal antibodies (MAbs) against APA were injected into mice, we observed strong binding of the MAbs to the basolateral membranes, whereas the MAbs bound only transiently to the brush borders of the proximal tubular epithelial cells. In parallel, APA itself disappeared from the brush borders by both endocytosis and shedding, whereas it was increasingly expressed on the basolateral sides. Using ultrastructural immunohistology, we found no evidence for transcellular transport of endocytosed APA to the basolateral side of the proximal tubular epithelial cells. The absence of transcellular transport was confirmed by experiments in which we used a low dose of the MAbs. Such a low dose did not result in binding of the MAbs to the brush borders and had no effect on the presence of APA in the brush borders of the proximal tubular epithelial cells. In these experiments we still could observe binding of the MAbs to the basolateral membranes in parallel with the local appearance of APA. In addition, treatment of mice with chlorpromazine, a calmodulin antagonist that interferes with cytoskeletal function, largely inhibited the MAb-induced modulation of APA. Our studies suggest that injection of MAbs to APA specifically interrupts the normal intracellular traffic of this enzyme in proximal tubular epithelial cells. This intracellular transport is dependent on the action of cytoskeletal proteins.

  19. Status report on the development of a tubular electron beam ion source

    International Nuclear Information System (INIS)

    Donets, E.D.; Donets, E.E.; Becker, R.; Liljeby, L.; Rensfelt, K.-G.; Beebe, E.N.; Pikin, A.I.

    2004-01-01

    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/cm 2 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

  20. Micro-Drilling of Polymer Tubular Ultramicroelectrode Arrays for Electrochemical Sensors

    Directory of Open Access Journals (Sweden)

    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.

  1. Autoimmune Hepatitis with Distal Renal Tubular Acidosis and Small Bowel Partial Malrotation.

    Science.gov (United States)

    Kanaiyalal Modi, Tejas; Parikh, Hardik; Sadalge, Abhishek; Gupte, Amit; Bhatt, Pratin; Shukla, Akash

    2015-01-01

    Renal tubular acidosis (RTA) is not uncommon in patient with chronic autoimmune hepatitis (AIH), but usually remains latent. Here, we report a case of renal tubular acidosis RTA who presented with AIH. She was also diagnosed to have partial bowel malrotation. A 9-year-old girl, a case of distal RTA, presented with jaundice, abdominal distension and altered sensorium. She was diagnosed to be AIH, which was successfully treated with steroids and azathioprine. Coexistent midgut partial malrotation with volvulus was diagnosed during the treatment. She was treated successfully with anti-tuberculous treatment for cervical lymphadenitis. Autoimmune hepatitis should not be ruled out in each case of RTA presenting with jaundice. Modi TK, Parikh H, Sadalge A, Gupte A, Bhatt P, Shukla A. Autoimmune Hepatitis with Distal Renal Tubular Acidosis and Small Bowel Partial Malrotation. Euroasian J Hepato-Gastroenterol 2015;5(2):107-109.

  2. Use and benefit summary of General Electric Company thermocase insulated tubulars for steam enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Traynor, B.V. Jr.; Hawley, J.R.; Marziani, V.J.; Prevost, W.M.

    1982-01-01

    General Electric Co.'s (GE) first well-bore insulation in 1969 resulted from the industry's need to produce hot oil on Alaska's North Slope without damaging the permafrost. In the past 3 yr, over 500,000 linear ft of GE's Thermocase has been sold. Thermocase tubulars are in use in California, Wyoming, Texas, Canada, Venezuela, and the USSR. Thermocase insulated tubulars are being used in a wide range of reservoirs under a variety of completion designs. This study discusses field experience, thermal completion benefits afforded by Thermocase tubulars, a quantified economic evaluation in a 1000-ft application, as well as GE's product verification, test and rigid quality control program.

  3. Species diversity regarding the presence of proximal tubular progenitor cells of the kidney

    Directory of Open Access Journals (Sweden)

    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.

  4. Interferon-γ Reduces the Proliferation of Primed Human Renal Tubular Cells

    Directory of Open Access Journals (Sweden)

    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.

  5. Three-Dimensional Tubular MoS2/PANI Hybrid Electrode for High Rate Performance Supercapacitor.

    Science.gov (United States)

    Ren, Lijun; Zhang, Gaini; Yan, Zhe; Kang, Liping; Xu, Hua; Shi, Feng; Lei, Zhibin; Liu, Zong-Huai

    2015-12-30

    By using three-dimensional (3D) tubular molybdenum disulfide (MoS2) as both an active material in electrochemical reaction and a framework to provide more paths for insertion and extraction of ions, PANI nanowire arrays with a diameter of 10-20 nm can be controllably grown on both the external and internal surface of 3D tubular MoS2 by in situ oxidative polymerization of aniline monomers and 3D tubular MoS2/PANI hybrid materials with different amounts of PANI are prepared. A controllable growth of PANI nanowire arrays on the tubular MoS2 surface provides an opportunity to optimize the capacitive performance of the obtained electrodes. When the loading amount of PANI is 60%, the obtained MoS2/PANI-60 hybrid electrode not only shows a high specific capacitance of 552 F/g at a current density of 0.5 A/g, but also gives excellent rate capability of 82% from 0.5 to 30 A/g. The remarkable rate performance can be mainly attributed to the architecture with synergistic effect between 3D tubular MoS2 and PANI nanowire arrays. Moreover, the MoS2/PANI-60 based symmetric supercapacitor also exhibits the excellent rate performance and good cycling stability. The specific capacitance based on the total mass of the two electrodes is 124 F/g at a current density of 1 A/g and 79% of its initial capacitance is remained after 6000 cycles. The 3D tubular structure provides a good and favorable method for improving the capacitance retention of PANI electrode.

  6. The Test for Flow Characteristics of Tubular Fuel Assembly(II) - Experimental results and CFD analysis

    International Nuclear Information System (INIS)

    Park, Jong Hark; Chae, H. T.; Park, C.; Kim, H.

    2006-12-01

    A test facility had been established for the experiment of velocity distribution and pressure drop in a tubular fuel. A basic test had been conducted to examine the performance of the test loop and to verify the accuracy of measurement by pitot-tube. In this report, test results and CFD analysis for the hydraulic characteristics of a tubular fuel, following the previous tests, are described. Coolant velocities in all channels were measured using pitot-tube and the effect of flow rate change on the velocity distribution was also examined. The pressure drop through the tubular fuel was measured for various flow rates in range of 1 kg/s to 21 kg/s to obtain a correlation of pressure drop with variation of flow rate. In addition, a CFD(Computational Fluid Dynamics) analysis was also done to find out the hydraulic characteristics of tubular fuel such as velocity distribution and pressure drop. As the results of CFD analysis can give us a detail insight on coolant flow in the tubular fuel, the CFD method is a very useful tool to understand the flow structure and phenomena induced by fluid flow. The CFX-10, a commercial CFD code, was used in this study. The two results by the experiment and the CFD analysis were investigated and compared with each other. Overall trend of velocity distribution by CFD analysis was somewhat different from that of experiment, but it would be reasonable considering measurement uncertainties. The CFD prediction for pressure drop of a tubular fuel shows a tolerably good agreement with experiment within 8% difference

  7. In-Situ TEM-STM Observations of SWCNT Ropes/Tubular Transformations

    Science.gov (United States)

    Sola, F.; Lebron-Colon, M.; Ferreira, P. J.; Fonseca, L. F.; Meador, M. A.; Marin, C.

    2010-01-01

    Single-walled carbon nanotubes (SWCNTs) prepared by the HiPco process were purified using a modified gas phase purification technique. A TEM-STM holder was used to study the morphological changes of SWCNT ropes as a function of applied voltage. Kink formation, buckling behavior, tubular transformation and eventual breakdown of the system were observed. The tubular formation was attributed to a transformation from SWCNT ropes to multi-walled carbon nanotube (MWCNT) structures. It is likely mediated by the patching and tearing mechanism which is promoted primarily by the mobile vacancies generated due to current-induced heating and, to some extent, by electron irradiation.

  8. Facile Fabrication of Uniform Polyaniline Nanotubes with Tubular Aluminosilicates as Templates

    Directory of Open Access Journals (Sweden)

    Zhang Long

    2008-01-01

    Full Text Available AbstractThe 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.

  9. Strength characterization of tubular ceramic materials by flexure of semi-cylindrical specimens

    DEFF Research Database (Denmark)

    Kwok, Kawai; Kiesel, Lutz; Frandsen, Henrik Lund

    2014-01-01

    Mechanical strength at elevated temperatures and operating atmospheres needs to be characterized during development of tubular ceramic components for advanced energy technologies. Typical procedures are time-consuming because a large number of tests are required for a reliable statistical strength...... characterization and every specimen has to be subjected to the process conditions individually. This paper presents an efficient strength characterization methodology for tubular ceramics. The methodology employs flexure of semi-cylindrical specimens as the strength test and implements the tests within a facility...... conducted on oxygen transport membrane materials at room temperature and 850°C....

  10. Surface wave resonance and chirality in a tubular cavity with metasurface design

    Science.gov (United States)

    Qin, Yuzhou; Fang, Yangfu; Wang, Lu; Tang, Shiwei; Sun, Shulin; Liu, Zhaowei; Mei, Yongfeng

    2018-06-01

    Optical microcavities with whispering-gallery modes (WGMs) have been indispensable in both photonic researches and applications. Besides, metasurfaces, have attracted much attention recently due to their strong abilities to manipulate electromagnetic waves. Here, combining these two optical elements together, we show a tubular cavity can convert input propagating cylindrical waves into directed localized surface waves (SWs), enabling the circulating like WGMs along the wall surface of the designed tubular cavity. Finite element method (FEM) simulations demonstrate that such near-field WGM shows both large chirality and high local field. This work may stimulate interesting potential applications in e.g. directional emission, sensing, and lasing.

  11. Self-assembly of versatile tubular-like In2O3 nanostructures

    International Nuclear Information System (INIS)

    Zhong Miao; Zheng Maojun; Ma Li; Li Yanbo

    2007-01-01

    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

  12. Nonimaging secondary concentrators for large rim angle parabolic troughs with tubular absorbers.

    Science.gov (United States)

    Ries, H; Spirkl, W

    1996-05-01

    For parabolic trough solar collectors with tubular absorbers, we design new tailored secondary concentrators. The design is applicable for any rim angle of a parabolic reflector. With the secondary, the concentration can be increased by a factor of more than 2 with a compact secondary reflector consisting of a single piece, even for the important case of a rim angle of 90 deg. The parabolic reflector can be used without changes; the reduced absorber is still tubular but smaller than the original absorber and slightly displaced toward the primary.

  13. Stressed waveguides with tubular depressed-cladding inscribed in phosphate glasses by femtosecond hollow laser beams.

    Science.gov (United States)

    Long, Xuewen; Bai, Jing; Zhao, Wei; Stoian, Razvan; Hui, Rongqing; Cheng, Guanghua

    2012-08-01

    We report on the single-step fabrication of stressed optical waveguides with tubular depressed-refractive-index cladding in phosphate glasses by the use of focused femtosecond hollow laser beams. Tubelike low index regions appear under direct exposure due to material rarefaction following expansion. Strained compacted zones emerged in domains neighboring the tubular track of lower refractive index, and waveguiding occurs mainly within the tube core fabricated by the engineered femtosecond laser beam. The refractive index profile of the optical waveguide was reconstructed from the measured transmitted near-field intensity.

  14. Facile Fabrication of Uniform Polyaniline Nanotubes with Tubular Aluminosilicates as Templates

    Science.gov (United States)

    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.

  15. Evaluation of seismic behavior of a braced tubular steel structure by pseudodynamic testing

    International Nuclear Information System (INIS)

    Shiny, P.B.; Javadian-Gilani, A.S.; Mahin, S.A.

    1984-01-01

    The inelastic seismic behavior of an X-braced, tubular steel frame is studied experimentally by means of pseudodynamic testing. The pseudodynamic method, which utilizes a numerical algorithm in the on-line computer control of a test specimen, can realistically simulate the seismic response of a structural model. This paper presents a brief outline of the experimental procedure and the results of the tubular frame tests, including the global responses, the inelastic energy-dissipation capabilities, and the failure mechanism of the frame at various excitation levels. Correlation of these results with previous experimental studies illustrates the feasibility and accuracy of the new test method

  16. Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

    Directory of Open Access Journals (Sweden)

    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.

  17. Conceptual bases of creation of the membrane device of tubular type for studying the in bioreactors

    Directory of Open Access Journals (Sweden)

    A. I. Klyuchnikov

    2017-01-01

    Full Text Available In this study, methods for intensifying micro- and ultrafiltration processes by controlling the concentration-polarization effect are considered and studied. The negative effect of concentration polarization on the process of separation of the filtered liquid and on the membrane surface is described (due to the increase in concentration, the selectivity and specific productivity of the membrane surface decrease. The physical picture of the flowing phenomena in a flat membrane channel with known geometric dimensions is considered, four sections with different effects on the filtration process are identified. The equation of material balance is analyzed by introducing boundary conditions into the criterion equation of material balance, with the aim of finding opportunities for mass transfer. It is revealed that the mass transfer coefficient km decreases, due to the growth of the thickness of the boundary layer. The main parameters significantly influencing the process of microfiltration are the flow rates G of the initial solution, the mass transfer coefficient km, and with decreasing km decreases and G. The analysis of theoretical and experimental data is carried out showing that the decisive role in the course of the microfiltration process is played by the motion regime of the initial solution, Physical-chemical properties, geometry of the membrane channel. The prospects for using the pulsating field in bioreactors and the need for a conceptual approach for the development of promising membrane devices are grounded. The need to create membranes of complex geometric shapes with the possibility of placing turbulent devices in them and the possibility of moving them relative to each other is considered, creating channels of variable cross-section, which will lead to the appearance of a sufficient number of possibilities for creating hydrodynamic instabilities of various intensities. The article touches upon the application of pulsation regimes of destruction or loosening of the polarization layer by means of reciprocating motion of the concentrate, periodic membrane regeneration by tangential pulsating flow or by using reverse pumping.

  18. Development of Tubular Type Underwater Discharge Reactor to decompose Fe-EDTA from aqueous solution

    International Nuclear Information System (INIS)

    Kang, Duck-Won; Kim, Seok-Tae; Kim, Jin Kil; Ki, Hyung-Dong

    2007-01-01

    In case of a nuclear industry, the wastewater is hardly generated in normal operating conditions aside from laundry rooms, particularly for wastewater contaminated by radioactive materials. However if the steam generator (SG) chemical cleaning works are carrying out, it is another story. In this case we have to predict wastewater production at least from several tons to several hundreds tons during the works. Actually Kori Unit 4 in Korea is preparing the advanced sludge conditioning agents (ASCAs) project at the next overhaul period, June-2007, to remove the tube sheet scale, and we are predicting that the 200 . 250 tons waste solutions are going to produce during this works. SG chemical cleaning waste solution containing chelating agents such as EDTA is hardly easy to purify and radioactive materials included in this solution make much harder. Therefore we must have technologies to purify this chemical cleaning waste solution. The best wastewater treatment system should have great adaptability, low environmental impact, low amount of hazardous waste, and low capital and operating costs. In this study we developed the underwater spark discharge system (USDS) to decompose Fe-EDTA from aqueous solution which is contaminated with radioactive materials

  19. Parametric study of the low-enriched uranium integrated Fort-Saint-Vrain element; comparative evaluation with the interacting tubular element

    International Nuclear Information System (INIS)

    Cerles, J.M.; Carvallo, G.; Vallepin, C.

    1971-11-01

    This paper presents a study of the influence of the different geometric and neutronic parameters on the calculation of the cycle with low-enriched uranium in a Fort-Saint-Vrain type brick. The study is divided in two parts: a stage of physics, essentially neutronics; an economical part where the costs are taken into account. At the level of studies of neutronics and costs, a parallel comparison is developed between the brick Fort-Saint-Vrain and the interacting tubular element, and even thorium. 6 refs. 29 figs [fr

  20. Effect of diuretics on renal tubular transport of calcium and magnesium.

    Science.gov (United States)

    Alexander, R Todd; Dimke, Henrik

    2017-06-01

    Calcium (Ca 2+ ) and Magnesium (Mg 2+ ) reabsorption along the renal tubule is dependent on distinct trans- and paracellular pathways. Our understanding of the molecular machinery involved is increasing. Ca 2+ and Mg 2+ reclamation in kidney is dependent on a diverse array of proteins, which are important for both forming divalent cation-permeable pores and channels, but also for generating the necessary driving forces for Ca 2+ and Mg 2+ transport. Alterations in these molecular constituents can have profound effects on tubular Ca 2+ and Mg 2+ handling. Diuretics are used to treat a large range of clinical conditions, but most commonly for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate sodium (Na + ) transport, but also indirectly affect renal Ca 2+ and Mg 2+ handling, i.e., by establishing a prerequisite electrochemical gradient. It is therefore not surprising that substantial alterations in divalent cation handling can be observed following diuretic treatment. The effects of diuretics on renal Ca 2+ and Mg 2+ handling are reviewed in the context of the present understanding of basal molecular mechanisms of Ca 2+ and Mg 2+ transport. Acetazolamide, osmotic diuretics, Na + /H + exchanger (NHE3) inhibitors, and antidiabetic Na + /glucose cotransporter type 2 (SGLT) blocking compounds, target the proximal tubule, where paracellular Ca 2+ transport predominates. Loop diuretics and renal outer medullary K + (ROMK) inhibitors block thick ascending limb transport, a segment with significant paracellular Ca 2+ and Mg 2+ transport. Thiazides target the distal convoluted tubule; however, their effect on divalent cation transport is not limited to that segment. Finally, potassium-sparing diuretics, which inhibit electrogenic Na + transport at distal sites, can also affect divalent cation transport. Copyright © 2017 the American Physiological Society.

  1. Evidence for a role of claudin 2 as a proximal tubular stress responsive paracellular water channel

    Energy Technology Data Exchange (ETDEWEB)

    Wilmes, Anja, E-mail: Anja.Wilmes@i-med.ac.at; Aschauer, Lydia; Limonciel, Alice; Pfaller, Walter; Jennings, Paul

    2014-09-01

    Claudins are the major proteins of the tight junctions and the composition of claudin subtypes is decisive for the selective permeability of the paracellular route and thus tissue specific function. Their regulation is complex and subject to interference by several factors, including oxidative stress. Here we show that exposure of cultured human proximal tubule cells (RPTEC/TERT1) to the immunosuppressive drug cyclosporine A (CsA) induces an increase in transepithelial electrical resistance (TEER), a decrease in dome formation (on solid growth supports) and a decrease in water transport (on microporous growth supports). In addition, CsA induced a dramatic decrease in the mRNA for the pore forming claudins -2 and -10, and the main subunits of the Na{sup +}/K{sup +} ATPase. Knock down of claudin 2 by shRNA had no discernable effect on TEER or dome formation but severely attenuated apical to basolateral water reabsorption when cultured on microporous filters. Generation of an osmotic gradient in the basolateral compartment rescued water transport in claudin 2 knock down cells. Inhibition of Na{sup +}/K{sup +} ATPase with ouabain prevented dome formation in both cell types. Taken together these results provide strong evidence that dome formation is primarily due to transcellular water transport following a solute osmotic gradient. However, in RPTEC/TERT1 cells cultured on filters under iso-osmotic conditions, water transport is primarily paracellular, most likely due to local increases in osmolarity in the intercellular space. In conclusion, this study provides strong evidence that claudin 2 is involved in paracellular water transport and that claudin 2 expression is sensitive to compound induced cellular stress. - Highlights: • Cyclosporine A increased TEER and decreased water transport in RPTEC/TERT1 cells. • Claudins 2 and 10 were decreased in response to cyclosporine A. • Knock down of claudin 2 inhibited water transport in proximal tubular cells. • We

  2. Validation of surface crack stress intensity factors of a tubular K-joint

    International Nuclear Information System (INIS)

    Lie, S.T.; Lee, C.K.; Chiew, S.P.; Shao, Y.B.

    2005-01-01

    Tubular K-joints are encountered widely in offshore structures, and the prediction of damaged joints depends very much on the accuracy of stress intensity factor solutions (SIFs). No parametric equations and very few results have been proposed and published in the literature for estimating the SIFs of any K-joints subjected to complex loading conditions. In this paper, a mesh generation method proposed previously for the Y-joint and T-joint has been extended to the K-joint. This method is realized by dividing the K-joint into several sub-zones with each zone consisting of different types of elements and mesh densities. This method has a distinct advantage of controlling the mesh quality, and most importantly the aspect ratio of the elements along the crack front. When the mesh of all the sub-zones has been generated automatically and completely, they are merged to form the complete model. The two most commonly used methods, namely the J-integral and displacement extrapolation, are used to evaluate the SIF values along the crack front of a typical K-joint. To validate the accuracy of these computed SIFs, a full-scale K-joint specimen was tested to failure under fatigue loading conditions. The standard alternating current potential drop (ACPD) technique was used to monitor the rate of crack propagation of the surface crack located at the hot spot stress region. Using the given material parameters C and m, the experimental SIFs were deduced, and they are found to be in good agreement with the computed SIFs obtained from the generated models. Hence, the proposed finite element models are both efficient and reliable

  3. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    International Nuclear Information System (INIS)

    Machiguchi, Toshihiko; Nakamura, Tatsuo

    2013-01-01

    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. Single-step fabrication of stressed waveguides with tubular depressed-cladding in phosphate glasses using ultrafast vortex laser beams

    Directory of Open Access Journals (Sweden)

    Cheng Guanghua

    2013-11-01

    Full Text Available We report on the fabrication of the stressed optical waveguide with tubular depressed-refractive-index cladding in phosphate glasses by use of femtosecond vortex beam. Strained regions were emerged in domains surrounding the tubular track. Waveguiding occurs mainly within the tube induced by femtosecond laser.

  5. Relationship between vibrations of tubular elements of power equipment and dynamic characteristics of longitudinal two-phase flow

    International Nuclear Information System (INIS)

    Fokin, B.S.; Gol'dberg, E.N.

    1979-01-01

    Analytical results of statistical nature of forces exciting vibrations of tubular elements, which are flown around with two-phase flows, are given. Relationships for the calculation of a mean-square amplitude and vibration frequency of a tubular element flown around with a two-phase mixture have been obtained. The relationships are confirmed experimentally

  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

    NARCIS (Netherlands)

    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

  7. Tubular and endothelial chimerism in renal allografts using fluorescence and chromogenic in situ hybridization (FISH, CISH) technology.

    Science.gov (United States)

    Varga, Zsuzsanna; Gaspert, Ariana; Behnke, Silvia; von Teichman, Adriana; Fritzsche, Florian; Fehr, Thomas

    2012-04-01

    The role of endothelial and tubular chimerism in renal allograft adaptation and rejection varies in different studies. We addressed the correlation between different clinico-pathological settings and sex-chromosomal endothelial and/or tubular chimerism in renal allografts. We examined the presence or absence of the X and Y chromosomes by fluorescence and chromogenic in situ hybridization (FISH, CISH) methodology on paraffin embedded kidney biopsies in 16 gender mismatched renal transplants (1 to 12 years post-transplantation). Twelve patients were male, four female. Four groups were selected: (i) Vascular calcineurin inhibitor toxicity without rejection; (ii) T-cell mediated vascular rejection; (iii) antibody mediated rejection; and (iv) C4d-positivity in AB0-incompatible transplants with or without rejection. Twelve non-transplant kidney biopsies (8 female, 4 male) were used as controls. Tubular chimerism was detected more frequently (69%) than endothelial chimerism (12%) in renal transplants. One of 12 control patients had tubular and endothelial chimeric cells (8%). The Y chromosome occurred in 8/12 male recipients (67%) in tubular epithelial cells and in 5/12 male recipients (42%) in endothelial cells. Double X chromosomes were detected in 3/4 female recipients in tubular epithelium. Tubular chimerism occurred more often with endothelial chimerism and capillaritis without correlation with other parameters, such as rejection. Combined Y chromosomal tubular and lymphatic endothelial chimerism correlated with T-cell mediated vascular rejection in two out of three patients (66%). Combined Y chromosomal tubular and peritubular capillary chimerism correlated with antibody mediated C4d+ rejection in one out of two patients (50%). Tubular and/or endothelial chimerism occur frequently in gender mismatched renal allografts and, when combined, this is associated with T-cell mediated rejection. © 2012 The Authors. Pathology International © 2012 Japanese Society of

  8. Characterization of a novel, highly integrated tubular solid oxide fuel cell system using high-fidelity simulation tools

    Science.gov (United States)

    Kattke, K. J.; Braun, R. J.

    2011-08-01

    A novel, highly integrated tubular SOFC system intended for small-scale power is characterized through a series of sensitivity analyses and parametric studies using a previously developed high-fidelity simulation tool. The high-fidelity tubular SOFC system modeling tool is utilized to simulate system-wide performance and capture the thermofluidic coupling between system components. Stack performance prediction is based on 66 anode-supported tubular cells individually evaluated with a 1-D electrochemical cell model coupled to a 3-D computational fluid dynamics model of the cell surroundings. Radiation is the dominate stack cooling mechanism accounting for 66-92% of total heat loss at the outer surface of all cells at baseline conditions. An average temperature difference of nearly 125 °C provides a large driving force for radiation heat transfer from the stack to the cylindrical enclosure surrounding the tube bundle. Consequently, cell power and voltage disparities within the stack are largely a function of the radiation view factor from an individual tube to the surrounding stack can wall. The cells which are connected in electrical series, vary in power from 7.6 to 10.8 W (with a standard deviation, σ = 1.2 W) and cell voltage varies from 0.52 to 0.73 V (with σ = 81 mV) at the simulation baseline conditions. It is observed that high cell voltage and power outputs directly correspond to tubular cells with the smallest radiation view factor to the enclosure wall, and vice versa for tubes exhibiting low performance. Results also reveal effective control variables and operating strategies along with an improved understanding of the effect that design modifications have on system performance. By decreasing the air flowrate into the system by 10%, the stack can wall temperature increases by about 6% which increases the minimum cell voltage to 0.62 V and reduces deviations in cell power and voltage by 31%. A low baseline fuel utilization is increased by decreasing the

  9. Isomyosin expression patterns in tubular stages of chicken heart development: a 3-D immunohistochemical analysis

    NARCIS (Netherlands)

    de Jong, F.; Geerts, W. J.; Lamers, W. H.; Los, J. A.; Moorman, A. F.

    1987-01-01

    The 3-D distribution of atrial and ventricular isomyosins is analysed in tubular chicken hearts (stage 12+ to 17 (H/H)) using antibodies specific for adult chicken atrial and ventricular myosin heavy chains, respectively. At stage 12+ (H/H) all myocytes express the atrial isomyosin; furthermore, all

  10. Confined diffusion in tubular structures analyzed by fluorescence correlation spectroscopy on a mirror

    International Nuclear Information System (INIS)

    Etienne, Emilien; Lenne, Pierre-Francois; Sturgis, James N.; Rigneault, Herve

    2006-01-01

    In fluorescence correlation spectroscopy (FCS) analysis it is generally assumed that molecular species diffuse freely in volumes much larger than the three-dimensional FCS observation volume. However, this standard assumption is not valid in many measurement conditions, particularly in tubular structures with diameters in the micrometer range, such as those found in living cells (organelles, dendrites) and microfluidic devices (capillaries,reaction chambers). As a result the measured autocorrelation functions (ACFs) deviate from those predicted for free diffusion, and this can shift the measured diffusion coefficient by as much as ∼50% when the tube diameter is comparable with the axial extension of the FCS observation volume. We show that the range of validity of the FCS measurements can be drastically improved if the tubular structures are located in the close vicinity of a mirror on which FCS is performed. In this case a new fluctuation time in the ACF, arising from the diffusion of fluorescent probes in optical fringes,permits measurement of the real diffusion coefficient within the tubular structure without assumptions about either the confined geometry orthe FCS observation volume geometry. We show that such a measurement can be done when the tubular structure contains at least one pair of dark and bright fringes resulting from interference between the incoming and the reflected excitation beams on the mirror surface. Measurement of the diffusion coefficient of the enhanced green fluorescent protein (EGFP) and IscS-EGFP in the cytoplasm of living Escherichiacoli illustrates the capabilities of the technique

  11. Defective proximal tubular function in a patient with I-cell disease.

    NARCIS (Netherlands)

    Bocca, G.; Monnens, L.A.H.

    2003-01-01

    A girl with a proven diagnosis of I-cell disease is presented. Proximal tubular dysfunction was characterized by increased excretion of low molecular proteins, aminoaciduria, hyperphosphaturia, and high/slightly increased urinary calcium. The concentration of 1,25-dihydroxycalciferol in serum was

  12. A quantitative model of the cardiac ventricular cell incorporating the transverse-axial tubular system

    Czech Academy of Sciences Publication Activity Database

    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

  13. The effect of RAAS blockade on markers of renal tubular damage in diabetic nephropathy

    DEFF Research Database (Denmark)

    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)....

  14. Glomerular and tubular damage markers are elevated in patients with diabetes

    NARCIS (Netherlands)

    Nauta, Ferdau L.; Boertien, Wendy E.; Bakker, Stephan J. L.; van Goor, Harry; van Oeveren, Wim; de Jong, Paul E.; Bilo, Henk; Gansevoort, Ron T.

    OBJECTIVE: We investigated in a cross-sectional study the levels of serum and urinary damage markers in diabetic patients (n = 94) and nondiabetic control subjects (n = 45) to study the association of glomerular (IgG), proximal tubular (kidney injury molecule [KIM]-1, N-acetyl-β-d-glucosaminidase

  15. Tolerance-based Structural Design of Tubular-Structure Loading Equipments

    Directory of Open Access Journals (Sweden)

    Jiping Lu

    2011-05-01

    is worked out under different ball screws, trapezoidal screw threads, worm and worm gears. To meet the requirement of tolerance in tubular-structure assembly, mechanisms for all motions are defined. The design of loading equipment is tested and assessed by experiments, and the result shows the design is highly qualified for its assembly.

  16. Normalized Urinary Flow at Puberty after Tubularized Incised Plate Urethroplasty for Hypospadias in Childhood.

    Science.gov (United States)

    Andersson, Marie; Doroszkiewicz, Monika; Arfwidsson, Charlotte; Abrahamsson, Kate; Sillén, Ulla; Holmdahl, Gundela

    2015-11-01

    An obstructive urinary flow pattern is frequently seen after tubularized incised plate urethroplasty for hypospadias. However, the significance of this finding has not been determined and long-term results are few. We describe postoperative long-term uroflowmetry results after puberty in males who underwent tubularized incised plate urethroplasty in childhood. A total of 126 boys underwent tubularized incised plate urethroplasty for distal penile to mid shaft hypospadias at Queen Silvia Children's Hospital in Gothenburg between 1999 and 2003. Of the patients 48 were toilet trained at surgery. We report on 40 patients who had data available at 2 and 12 months postoperatively, 7 years postoperatively and at puberty (median age 15.0 years, range 13.7 to 17.1). Of the patients 31 had distal and 9 had mid penile hypospadias. Clinical examination, urinary medical history, uroflowmetry and ultrasound measuring residual urine were performed. Maximum urinary flow was correlated to age and voided volume, using Miskolc nomograms for comparison of percentiles. At 1 year postoperatively 15 boys (37.5%) had normal urinary flow (above 25th percentile), compared to 16 (40%) at 7 years and 38 (95%) at puberty (p puberty for boys with hypospadias treated with tubularized incised plate urethroplasty. Unless symptoms occur, a conservative approach seems preferable. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. MATHEMATICAL MODELLING OF PREFERED SOLUTIONS CHOICE FUNCTION FOR TUBULAR GAS HEATERS BY EXPERIMENTAL INFORMATIONS

    Directory of Open Access Journals (Sweden)

    BARSUK R. V.

    2016-08-01

    Full Text Available Annotation. Problems formulation. The article deals with choice functions building of preferred solutions by experimental information for tubular gas heater working on fuel granules - pellets.Further choice functions using for making technical solutions by tubular gas heaters construction and designing. Recently research analysis. There are works about choice functions construction by separate presents are examined. But full chose functions building by separate presents are not examined. Aims and tasks. There are setting aim to develop full choice functions mathematical model on separate presents by authors. The expert are connect to primary experimental data’s evaluation that estimates separate results by output functions (criteria. Its evaluations issue in experimental points paired comparison’s table form. Thus, there are necessary construct binary choice relations presents on experimental “points” set by expert that then using for full choice function’s constructing. Conclusions. There are choice function’s construction’s sequence are sets. There are posed point comparison results that characterized tubular gas heater’s condition with expert’s evaluation using. Also posed output functions comparisons by which can be characterized improving tubular gas heater’s performance or vice versa.

  18. 75 FR 49527 - Metaldyne Corporation, Metaldyne Tubular Products, Currently Known as Flexible Metal, Inc...

    Science.gov (United States)

    2010-08-13

    ..., Metaldyne Tubular Products, Currently Known as Flexible Metal, Inc., Powertrain Division, Hamburg, MI... certification for workers of the subject firm. The workers are engaged in the production of exhaust manifolds and turbo tubes for the automotive industry. Information shows that on June 10, 2010, Flexible Metals...

  19. Gremlin Activates the Smad Pathway Linked to Epithelial Mesenchymal Transdifferentiation in Cultured Tubular Epithelial Cells

    Directory of Open Access Journals (Sweden)

    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.

  20. Dynamics of catalytic tubular microjet engines: dependence on geometry and chemical environment.

    Science.gov (United States)

    Li, Jinxing; Huang, Gaoshan; Ye, Mengmeng; Li, Menglin; Liu, Ran; Mei, Yongfeng

    2011-12-01

    Strain-engineered tubular microjet engines with various geometric dimensions hold interesting autonomous motions in an aqueous fuel solution when propelled by catalytic decomposition of hydrogen peroxide to oxygen and water. The catalytically-generated oxygen bubbles expelled from microtubular cavities propel the microjet step by step in discrete increments. We focus on the dynamics of our tubular microjets in one step and build up a body deformation model to elucidate the interaction between tubular microjets and the bubbles they produce. The average microjet velocity is calculated analytically based on our model and the obtained results demonstrate that the velocity of the microjet increases linearly with the concentration of hydrogen peroxide. The geometric dimensions of the microjet, such as length and radius, also influence its dynamic characteristics significantly. A close consistency between experimental and calculated results is achieved despite a small deviation due to the existence of an approximation in the model. The results presented in this work improve our understanding regarding catalytic motions of tubular microjets and demonstrate the controllability of the microjet which may have potential applications in drug delivery and biology.

  1. Impact-friction vibrations of tubular systems. Numerical simulation and experimental validation

    International Nuclear Information System (INIS)

    Jacquart, G.

    1993-05-01

    This note presents a summary on the numerical developments made to simulate impact-friction vibrations of tubular systems, detailing the algorithms used and the expression of impact and friction forces. A synthesis of the experimental results obtained on MASSIF workbench is also presented, as well as their comparison with numerical computations in order to validate the numerical approach. (author). 5 refs

  2. High-temperature, high-pressure bonding of nested tubular metallic components

    International Nuclear Information System (INIS)

    Quinby, T.C.

    1980-01-01

    This invention is a tool for effecting high-temperature, high compression bonding between the confronting faces of nested, tubular, metallic components. In a typical application, the tool is used to produce tubular target assemblies for irradiation in nuclear reactors or particle accelerators, the target assembly comprising a uranium foil and an aluminum-alloy substrate. The tool preferably is composed throughout of graphite. It comprises a tubular restraining member in which a mechanically expandable tubular core is mounted to form an annulus with the member. The components to be bonded are mounted in nested relation in the annulus. The expandable core is formed of individually movable, axially elongated segments whose outer faces cooperatively define a cylindrical pressing surface and whose inner faces cooperatively define two opposed, inwardly tapered, axial bores. Tapered rams extend respectively into the bores. The loaded tool is mounted in a conventional hot-press provided with evacuation means, heaters for maintaining its interior at bonding temperature, and hydraulic cylinders for maintaining a selected inwardly directed pressure on the tapered rams. With the hotpress evacuated and the loaded tool at the desired temperature, the cylinders are actuated to apply the selected pressure to the rams. The rams in turn expand the segmented core to maintain the nested components in compression against the restraining member. These conditions are maintained until the confronting faces of the nested components are joined in a continuous, uniform bond characterized by high thermal conductivity

  3. Effect of cyclosporine therapy in transplanted patients-diagnostic values of tubular markers

    Directory of Open Access Journals (Sweden)

    Todor Gruev

    2003-09-01

    Full Text Available The introduction of cyclosporine A (CsA into the clinical practice has resulted in a major improvement in the short-term outcomes of solid organ transplantation and treatment of autoimune diseases. Chronic ScA nephrotoxicity has been described in kidneys of recepients of renal and other organ allografts. However, the exact mechanism underlying the development of fibrosis in chronic CsA nephrotoxicity has remained poorly understood. Evaluation with the validation data set showed that noninvasive urine protein differentiation might be a useful diagnostic strategy in nephrology. Over the past decade numerous studies in patients after transplantation have demonstrated that renal tubular cell injury after a toxic insult, results in sloughing of tubular debris and cell into the tubular lumen with eventual obstruction of tubular flow, increased intratubular pressure and backleak of glomerular filtrate out of the tubule. Urinary enzymes and low molecular proteins have been recommended as useful markers for the detection of changes in the kidney tissue in cases after renal transplantation. The aim of our study was to monitor the concentration and eventual nephrotoxic effect of Cyclosporine A using the concentration of low molecular proteins α-1-microglobulin and β−2-microglobulin, serum Cystatin C, as well as the concentration of isoform of GST-α and π.

  4. Seamless vascularized large-diameter tubular collagen scaffolds reinforced with polymer knittings for esophageal regenerative medicine

    NARCIS (Netherlands)

    Hoogenkamp, H.R.; Koens, M.J.W.; Geutjes, P.J.; Ainoedhofer, H.; Wanten, G.J.A.; Tiemessen, D.M.; Hilborn, J.; Gupta, B.; Feitz, W.F.J.; Daamen, W.F.; Saxena, A.K.; Oosterwijk, E.; Kuppevelt, T.H. van

    2014-01-01

    A clinical demand exists for alternatives to repair the esophagus in case of congenital defects, cancer, or trauma. A seamless biocompatible off-the-shelf large-diameter tubular scaffold, which is accessible for vascularization, could set the stage for regenerative medicine of the esophagus. The use

  5. Gas-permeable hydrophobic tubular membranes for ammonia recovery in bio-electrochemical systems

    NARCIS (Netherlands)

    Kuntke, P.; Zamora, P.; Saakes, M.; Buisman, C.J.N.; Hamelers, H.V.M.

    2016-01-01

    The application of a gas-permeable hydrophobic tubular membrane in bio-electrochemical systems enables efficient recovery of ammonia (NH3) from their cathode compartments. Due to a hydrogen evolution reaction at the cathode, no chemical addition was required to increase the pH for

  6. 78 FR 41421 - Certain Oil Country Tubular Goods From India, Korea, Philippines, Saudi Arabia, Taiwan, Thailand...

    Science.gov (United States)

    2013-07-10

    ... (Preliminary)] Certain Oil Country Tubular Goods From India, Korea, Philippines, Saudi Arabia, Taiwan, Thailand.... 1671b(a) and 1673b(a)) (the Act) to determine whether there is a reasonable indication that an industry... of an industry in the United States is materially retarded, by reason of imports from India, Korea...

  7. 78 FR 52213 - Certain Oil Country Tubular Goods From India, Korea, the Philippines, Saudi Arabia, Taiwan...

    Science.gov (United States)

    2013-08-22

    ... (Preliminary)] Certain Oil Country Tubular Goods From India, Korea, the Philippines, Saudi Arabia, Taiwan...), that there is a reasonable indication that an industry in the United States is materially injured by reason of imports from India, Korea, the Philippines, Saudi Arabia, Taiwan, Thailand, Turkey, Ukraine...

  8. A technical case report on use of tubular retractors for anterior cervical spine surgery.

    Science.gov (United States)

    Kulkarni, Arvind G; Patel, Ankit; Ankith, N V

    2017-12-19

    The authors put-forth this technical report to establish the feasibility of performing an anterior cervical corpectomy and fusion (ACCF) and a two-level anterior cervical discectomy and fusion (ACDF) using a minimally invasive approach with tubular retractors. First case: cervical spondylotic myelopathy secondary to a large postero-inferiorly migrated disc treated with corpectomy and reconstruction with a mesh cage and locking plate. Second case: cervical disc herniation with radiculopathy treated with a two-level ACDF. Both cases were operated with minimally invasive approach with tubular retractor using a single incision. Technical aspects and clinical outcomes have been reported. No intra or post-operative complications were encountered. Intra-operative blood loss was negligible. The patients had a cosmetic scar on healing. Standard procedure of placement of tubular retractors is sufficient for adequate surgical exposure with minimal invasiveness. Minimally invasive approach to anterior cervical spine with tubular retractors is feasible. This is the first report on use of minimally invasive approach for ACCF and two-level ACDF.

  9. The choice between cooled tubular reactor models: analysis of the hot spot

    NARCIS (Netherlands)

    Westerink, E.J.; Koster, N.; Westerterp, K.R.

    1990-01-01

    The applicability of the one-dimensional pseudo-homogeneous model of the cooled tubular reactor is studied. Using the two-dimensional model as the more accurate one we compared both models by studying the influence of the design and operating variables on the conditions in the hot spot of the

  10. An all-glass solid sampling device for open tubular columns in gas chromatography

    NARCIS (Netherlands)

    Cox, T.P.H.; vd Berg, P.M.J.

    1972-01-01

    An all-glass system for direct sample-introduction of high-boiling compounds onto open tubular columns is described. The standard deviation for quantitative measurements is less than 2.7%. The loss in resolving power of capillary columns, due to this injection system is negligible. The system is

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

    DEFF Research Database (Denmark)

    Faarup, Poul; Nørgaard, Tove; Hegedüs, Viktor

    2004-01-01

    The background and mechanisms of ischemic acute tubular necrosis are still essentially unclarified. Therefore a quantitative morphological technique was applied for evaluation of the early structural changes in different fractions of the proximal convoluted tubule in the rat renal cortex. In male...

  12. High-temperature, high-pressure bonding of nested tubular metallic components

    Science.gov (United States)

    Quinby, T.C.

    A tool is described for effecting high-temperature, high-compression bonding between the confronting faces of nested, tubular, metallic components. In a typical application, the tool is used to produce tubular target assemblies for irradiation in nuclear reactors or particle accelerators. The target assembly comprising a uranum foil and an aluninum-alloy substrate. The tool is composed of graphite. It comprises a tubular restraining member in which a mechanically expandable tubular core is mounted to form an annulus. The components to be bonded are mounted in nested relation in the annulus. The expandable core is formed of individually movable, axially elongated segments whose outer faces cooperatively define a cylindrical pressing surface and whose inner faces cooperatively define two opposed, inwardly tapered, axial bores. Tapered rams extend into the bores. The loaded tool is mounted in a conventional hot-press provided with evacuation means, heaters for maintaining its interior at bonding temperature, and hydraulic cylinders for maintaining a selected inwardly directed pressure on the tapered rams. With the hot-press evacuated and the loaded tool at the desired temperature, the cylinders are actuated to apply the selected pressure to the rams. The rams in turn expand the segmented core to maintain the nested components in compression against the restraining member. These conditions are maintained until the confronting faces of the nested components are joined in a continuous, uniform bond characterized by high thermal conductivity.

  13. Analysis and design of a slotless tubular permanent magnet actuator for high acceleration applications

    NARCIS (Netherlands)

    Meessen, K.J.; Paulides, J.J.H.; Lomonova, E.A.

    2009-01-01

    This paper presents the design of a linear actuator for high acceleration applications. In the analysis, a slotless tubular permanent magnet actuator is modeled by means of semianalytical field solutions. Several slotless topologies are modeled and compared to achieve the highest acceleration. A

  14. Whole‐exome sequencing as a diagnostic tool for distal renal tubular acidosis

    Directory of Open Access Journals (Sweden)

    Paula Cristina Barros Pereira

    2015-11-01

    Conclusion: These results confirm the value of whole‐exome sequencing for the study of rare and complex genetic nephropathies, allowing the identification of novel and recurrent mutations. Furthermore, for the first time the application of this molecular method in renal tubular diseases has been clearly demonstrated.

  15. Effects of modifiers in packed and open-tubular supercritical fluid chromatography

    NARCIS (Netherlands)

    Janssen, J.G.M.; Schoenmakers, P.J.; Cramers, C.A.M.G.

    1991-01-01

    The applicability of packed and open columns for supercritical fluid chromatography using pure carbon dioxide for the elution of a number of selected test components was investigated. It is showns that the number of solutes that can be eluted as symmetrical peaks is much larger in open-tubular

  16. Glomerular filtration and tubular secretion of MAG-3 in the rat kidney

    International Nuclear Information System (INIS)

    Mueller-Suur, R.M.; Mueller-Suur, C.

    1989-01-01

    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. Evaluating a steel beam’s rigid connection to a concrete filled tubular column when submitted to dynamic load

    Directory of Open Access Journals (Sweden)

    Maritza Uribe Vallejo

    2009-01-01

    Full Text Available Using prequalified connections during the structural design stage becomes increasingly necessary when developing structural en-gineering projects which include steel elements; this is so that the steel elements’ appropriate behavior can be ensured according to the structural system and seismic demand. Unfortunately, the international entities providing this type of information (i.e. FEMA only have a limit series of prequalified connections and such series do not include rigid connections between steel beams and concrete filled tubular (CFT columns having an extended end plate, which has become a very widespread building practice in Colombia. This paper describes the most important aspects of a study at the Universidad Nacional de Colombia concerning the behavior of a steel beam rigidly connected to a CFT-column, using six physical models having different width-thickness ratio (b/t columns. ANSYS v.10 software was used for studying theoretical models (finite elements analysis for comparative analysis of cyclic test theoretical and experimental results for each specimen presented for the qualification phase. The six tested specimens’ hysteretic curves are presented. Several conclusions are drawn concerning finite element validation for this type of connection and the influence of width-thickness ratio (b/t variation and design recommendations for suitable behavior under dynamic loads when this type of connection was used.

  18. The urinary excretion of metformin, ceftizoxime and ofloxacin in high serum creatinine rats: Can creatinine predict renal tubular elimination?

    Science.gov (United States)

    Ma, Yan-Rong; Zhou, Yan; Huang, Jing; Qin, Hong-Yan; Wang, Pei; Wu, Xin-An

    2018-03-01

    The renal excretion of creatinine and most drugs are the net result of glomerular filtration and tubular secretion, and their tubular secretions are mediated by individual transporters. Thus, we hypothesized that the increase of serum creatinine (SCr) levels attributing to inhibiting tubular transporters but not glomerular filtration rate (GFR) could be used to evaluate the tubular excretion of drugs mediated by identical or partial overlap transporter with creatinine. In this work, we firstly developed the creatinine excretion inhibition model with normal GFR by competitively inhibiting tubular transporters, and investigated the renal excretion of metformin, ceftizoxime and ofloxacin in vivo and in vitro. The results showed that the 24-hour urinary excretion of metformin and ceftizoxime in model rats were decreased by 25% and 17% compared to that in control rats, respectively. The uptake amount and urinary excretion of metformin and ceftizoxime could be inhibited by creatinine in renal cortical slices and isolated kidney perfusion. However, the urinary excretion of ofloxacin was not affected by high SCr. These results showed that the inhibition of tubular creatinine transporters by high SCr resulted to the decrease of urinary excretion of metformin and ceftizoxime, but not ofloxacin, which implied that the increase of SCr could also be used to evaluate the tubular excretion of drugs mediated by identical or partial overlap transporter with creatinine in normal GFR rats. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Versatility of tubularized incised plate urethroplasty in the ...

    African Journals Online (AJOL)

    Results: All families were happy with penile aesthetic appearance. The total number of boys with different types of hypospadias was 175 (145 1ry and 30 2ry). Out of 175 cases, the overall urethrocutaneous fistula rate was 11 (6.29%), and the overall rates for glanular dehiscence, urethral stricture, meatal stenosis and ...

  20. Role of IGFBP7 in Diabetic Nephropathy: TGF-β1 Induces IGFBP7 via Smad2/4 in Human Renal Proximal Tubular Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Jun Watanabe

    Full Text Available Tubular injury is one of the important determinants of progressive renal failure in diabetic nephropathy (DN, and TGF-β1 has been implicated in the pathogenesis of tubulointerstitial disease that characterizes proteinuric renal disease. The aim of this study was to identify novel therapeutic target molecules that play a role in the tubule damage of DN. We used an LC-MS/MS-based proteomic technique and human renal proximal epithelial cells (HRPTECs. Urine samples from Japanese patients with type 2 diabetes (n = 46 were used to quantify the candidate protein. Several proteins in HRPTECs in cultured media were observed to be driven by TGF-β1, one of which was 33-kDa IGFBP7, which is a member of IGFBP family. TGF-β1 up-regulated the expressions of IGFBP7 mRNA and protein in a dose- and time-dependent fashion via Smad2 and 4, but not MAPK pathways in HRPTECs. In addition, the knockdown of IGFBP7 restored the TGF-β1-induced epithelial to mesenchymal transition (EMT. In the immunohistochemical analysis, IGFBP7 was localized to the cytoplasm of tubular cells but not that of glomerular cells in diabetic kidney. Urinary IGFBP7 levels were significantly higher in the patients with macroalbuminuria and were correlated with age (r = 0.308, p = 0.037, eGFR (r = -0.376, p = 0.01, urinary β2-microglobulin (r = 0.385, p = 0.008, and urinary N-acetyl-beta-D-glucosaminidase (NAG (r = 0.502, p = 0.000. A multivariate regression analysis identified urinary NAG and age as determinants associated with urinary IGFBP7 levels. In conclusion, our data suggest that TGF-β1 enhances IGFBP7 via Smad2/4 pathways, and that IGFBP7 might be involved in the TGF-β1-induced tubular injury in DN.

  1. Identification of genomic biomarkers for concurrent diagnosis of drug-induced renal tubular injury using a large-scale toxicogenomics database

    International Nuclear Information System (INIS)

    Kondo, Chiaki; Minowa, Yohsuke; Uehara, Takeki; Okuno, Yasushi; Nakatsu, Noriyuki; Ono, Atsushi; Maruyama, Toshiyuki; Kato, Ikuo; Yamate, Jyoji; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro

    2009-01-01

    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. Perigraft Plug Embolization of the Internal Iliac Artery and Implantation of a Bifurcated Stentgraft: One Treatment Option for Insufficient Tubular Stentgraft Repair of a Common Iliac Artery Aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Goltz, Jan Peter, E-mail: janpeter.goltz@uksh.de; Loesaus, Julia; Frydrychowicz, Alex; Barkhausen, Jörg [University Hospital of Schleswig-Holstein, Department for Radiology and Nuclear Medicine (Germany); Wiedner, Marcus [University Hospital of Schleswig-Holstein, Clinic for Surgery (Germany)

    2016-02-15

    We report an endovascular technique for the treatment of type Ia endoleak after a plain tubular stentgraft had been implanted for a large common iliac artery aneurysm with an insufficient proximal landing zone and without occlusion of the hypogastric in another hospital. CT follow-up showed an endoleak with continuous sac expansion over 12 months. This was classified as type Ia by means of dynamic contrast-enhanced MRI. Before a bifurcated stentgraft was implanted to relocate the landing zone more proximally, the still perfused ipsilateral hypogastric artery was embolized to prevent a type II endoleak. A guidewire was manipulated alongside the indwelling stentgraft. The internal iliac artery could then be selectively intubated followed by successful plug embolization of the vessel’s orifice despite the stentgraft being in place.

  3. Use of graphite layer open tubular (GLOT) in environmental analysis; Impiego di colonne GLOT (Graphite Layer Open Tubular) nell`analisi ambientale

    Energy Technology Data Exchange (ETDEWEB)

    Bruner, F.; Lattanzi, L. [Urbino Univ. (Italy). Istituto di Scienze Chimiche, Centro di Studio per la Chimica e le Tecnologie Strumentali Avanzate; Borghesi, P. [Centro Ricerca e Sviluppo, Enichem Elastomeri, Ravenna (Italy)

    1996-06-01

    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. Effect of tubular damage by mercuric chloride on kidney function and some urinary enzymes in the dog

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, B G; Price, R G; Topham, J C

    1973-01-01

    Alkaline and acid phosphatases, ..beta..-glucosidase, ..beta..-galactosidase, N-acetyl-..beta..-glucosaminidase and lactate dehydrogenase were monitored in the urine and serum of dogs with renal tubular damage induced by a series of increasing doses of mercuric chloride. Evidence is presented that the assay of urinary alkaline and acid phosphatase is the most sensitive method of detecting renal tubular damage in the dog. The clearance of (/sup 14/C)-propranolol was compared before and after the administration of mercuric chloride. In the presence of tubular damage the blood half-life of propranolol and the rate of excretion of metabolites in the urine were increased. 35 references, 7 tables.

  5. Energy-saving measures in the electrocar. Pt. 1 and 2. 1. Energy-optimized recuperative braking. 2. Energy-optimized charging of traction batteries; Energiesparmassnahmen am Elektroauto. T. 1 und 2. T. 1: Energieoptimiertes rekuperatives Bremsen. T. 2: Energieoptimiertes Laden von Traktionsbatterien

    Energy Technology Data Exchange (ETDEWEB)

    Goetting, G.; Willer, B.; Knorr, R.

    2001-07-01

    The first part of the research project was titled ''energy-optimized recuperative braking''. In this part, several braking strategies, especially those for use in electro vehicles which in addition to the mechanical brakes of the vehicle also incorporate the electrical drive into the brake system were compared with the support of a simulation model and evaluated. The paper reports both on the simulation model used and on the possibilities of saving energy which can be achieved using the various braking strategies for differing driving cycles. In the second part of the research project, ''energy-optimized charging of traction batteries'', possible methods of charging traction batteries of electro vehicles are shown and assessed with regard to the battery efficiency under various conditions of application. [German] In dem unter der Ueberschrift 'Energieoptimiertes rekuperatives Bremsen' laufenden ersten Teil des Forschungsvorhabens wurden verschiedene und speziell fuer den Einsatz im Elektrofahrzeug entworfene Bremsstrategien, die neben den mechanischen Bremsen des Fahrzeugs auch den elektrischen Antrieb in das Bremssystem einbeziehen, mit Hilfe eines Simulationsmodells verglichen und bewertet. Im Bericht werden sowohl das verwendete Simulationsmodell erlaeutert als auch die energetischen Einsparmoeglichkeiten, die sich mit den verschiedenen Bremsstrategien fuer unterschiedliche Fahrzyklen erzielen lassen, aufgezeigt. Im zweiten Teil des Forschungsvorhabens ('Energieoptimiertes Laden von Traktionsbatterien') wurden moegliche Ladeverfahren fuer Traktionsbatterien von Elektrofahrzeugen aufgezeigt und hinsichtlich des Batteriewirkungsgrades bei unterschiedlichen Einsatzbedingungen beurteilt. In die Untersuchungen waren Blei-, NiMH-, NaNiCl{sub 2}- und Lithium-Batterien eingeschlossen. (orig.)

  6. A tubular hybrid Halbach/axially-magnetized permanent-magnet linear machine

    Directory of Open Access Journals (Sweden)

    Yi Sui

    2017-05-01

    Full Text Available A single-phase tubular permanent-magnet linear machine (PMLM with hybrid Halbach/axially-magnetized PM arrays is proposed for free-piston Stirling power generation system. Machine topology and operating principle are elaborately illustrated. With the sinusoidal speed characteristic of the free-piston Stirling engine considered, the proposed machine is designed and calculated by finite-element analysis (FEA. The main structural parameters, such as outer radius of the mover, radial length of both the axially-magnetized PMs and ferromagnetic poles, axial length of both the middle and end radially-magnetized PMs, etc., are optimized to improve both the force capability and power density. Compared with the conventional PMLMs, the proposed machine features high mass and volume power density, and has the advantages of simple control and low converter cost. The proposed machine topology is applicable to tubular PMLMs with any phases.

  7. Overall renal and tubular function during infusion of amino acids in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    sodium concentration] increased by 40% (P less than 0.001). Plasma renin concentration did not change significantly. 4. The results suggest that amino acids increase GFR by a primary effect on renal haemodynamics or, less likely, by reducing the signal to the tubuloglomerular feedback mechanism......1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during...... infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal...

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

    Directory of Open Access Journals (Sweden)

    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.

  9. The effect of thermal treatment on the mechanical properties of PLLA tubular specimens

    Directory of Open Access Journals (Sweden)

    Arbeiter Daniela

    2016-09-01

    Full Text Available Conventional permanent stent systems for vascular applications are associated with long-term risks, such as restenosis and thrombosis. To overcome these limitations, novel approaches using various biodegradable materials for stent construction have been investigated. In this context, thermal treatment of polymer materials is investigated to adjust the mechanical properties of biodegradable stents. In this work polymeric tubular specimens of biodegradable poly(L-lactide (PLLA were extruded and subjected to a molding process using different temperatures above glass transition temperature TG. Physicochemical properties of the molded samples were analyzed using DSC measurements and uniaxial tensile tests. The molding process resulted in a weakening of the PLLA tubular specimens with a simultaneous increase in the degree of crystallinity (χ.

  10. Modelling of alcohol fermentation in a tubular reactor with high biomass recycle

    Energy Technology Data Exchange (ETDEWEB)

    Narodoslawsky, M; Mittmannsgruber, H; Nagl, W; Moser, A

    1988-05-30

    Fermentation in tubular recycle reactors with high biomass concentrations is a way to boost productivity in alcohol production. A computer model has been developed to investigate the potential as well as to establish the limits of this process from a chemical engineering point of view. The model takes into account the kinetics of the reaction, the nonideality of flow and the segregation in the bioreactor. In accordance with literature, it is shown that tubular reactors with biomass recycle can improve productivity of alcohol fermentation substantially. With the help of the computer based reactor model it was also possible to estimate the detrimental effects of cell damage due to pumping. These effects are shown to play a major role, if the biomass separation is performed by filtration units which need high flow rates, e.g. tangential flow filters.

  11. Optimization Study of Shaft Tubular Turbine in a Bidirectional Tidal Power Station

    Directory of Open Access Journals (Sweden)

    Xinfeng Ge

    2013-01-01

    Full Text Available The shaft tubular turbine is a form of tidal power station which can provide bidirectional power. Efficiency is an important turbine performance indicator. To study the influence of runner design parameters on efficiency, a complete 3D flow-channel model of a shaft tubular turbine was developed, which contains the turbine runner, guide vanes, and flow passage and was integrated with hybrid grids calculated by steady-state calculation methods. Three aspects of the core component (turbine runner were optimized by numerical simulation. All the results were then verified by experiments. It was shown that curved-edge blades are much better than straight-edge blades; the optimal blade twist angle is 7°, and the optimal distance between the runner and the blades is 0.75–1.25 times the diameter of the runner. Moreover, the numerical simulation results matched the experimental data very well, which also verified the correctness of the optimal results.

  12. Tubular depressed cladding waveguide laser realized in Yb: YAG by direct inscription of femtosecond laser

    International Nuclear Information System (INIS)

    Tang, Wenlong; Zhang, Wenfu; Liu, Xin; Liu, Shuang; Cheng, Guanghua; Stoian, Razvan

    2015-01-01

    We report on the fabrication of tubular depressed cladding waveguides in single crystalline Yb:YAG by the direct femtosecond laser writing technique. Full control over the confined light spatial distribution is demonstrated by the photoinscription of high index contrast waveguides with tubular configuration. Under optical pumping, highly efficient laser oscillation in depressed cladding waveguide at 1030 nm is demonstrated. The maximum output power obtained is 68 mW with a slope efficiency of 35% for an outcoupling transmission of 50%. A slope efficiency as high as 44% is realized when the coupling output ratio is 91% and a low lasing threshold of 70 mW is achieved with the output coupling mirror of 10%. (paper)

  13. A tubular hybrid Halbach/axially-magnetized permanent-magnet linear machine

    Science.gov (United States)

    Sui, Yi; Liu, Yong; Cheng, Luming; Liu, Jiaqi; Zheng, Ping

    2017-05-01

    A single-phase tubular permanent-magnet linear machine (PMLM) with hybrid Halbach/axially-magnetized PM arrays is proposed for free-piston Stirling power generation system. Machine topology and operating principle are elaborately illustrated. With the sinusoidal speed characteristic of the free-piston Stirling engine considered, the proposed machine is designed and calculated by finite-element analysis (FEA). The main structural parameters, such as outer radius of the mover, radial length of both the axially-magnetized PMs and ferromagnetic poles, axial length of both the middle and end radially-magnetized PMs, etc., are optimized to improve both the force capability and power density. Compared with the conventional PMLMs, the proposed machine features high mass and volume power density, and has the advantages of simple control and low converter cost. The proposed machine topology is applicable to tubular PMLMs with any phases.

  14. Performance evaluation of fractional-slot tubular permanent magnet machines with low space harmonics

    Directory of Open Access Journals (Sweden)

    Wang Jiabin

    2015-12-01

    Full Text Available This paper evaluates the perforamnce of fractional-slot per pole winding configurations for tubular permanent magnet (PM machines that can effectively eliminate the most undesirable space harmonics in a simple and cost-effective manner. The benefits of the proposed machine topology winding configurations are illustrated through comparison with 9-slot, 10-pole tubular PM machine developed for a free piston energy converter under the same specification and volumetric constraints. It has been shown that the proposed machine topology results in more than 7 times reduction in the eddy current loss in the mover magnets and supporting tube, and hence avoids potential problem of excessive mover temperature and risk of demagnetization.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Hyperactivation of Nrf2 in early tubular development induces nephrogenic diabetes insipidus

    Science.gov (United States)

    Suzuki, Takafumi; Seki, Shiori; Hiramoto, Keiichiro; Naganuma, Eriko; Kobayashi, Eri H.; Yamaoka, Ayaka; Baird, Liam; Takahashi, Nobuyuki; Sato, Hiroshi; Yamamoto, Masayuki

    2017-01-01

    NF-E2-related factor-2 (Nrf2) regulates cellular responses to oxidative and electrophilic stress. Loss of Keap1 increases Nrf2 protein levels, and Keap1-null mice die of oesophageal hyperkeratosis because of Nrf2 hyperactivation. Here we show that deletion of oesophageal Nrf2 in Keap1-null mice allows survival until adulthood, but the animals develop polyuria with low osmolality and bilateral hydronephrosis. This phenotype is caused by defects in water reabsorption that are the result of reduced aquaporin 2 levels in the kidney. Renal tubular deletion of Keap1 promotes nephrogenic diabetes insipidus features, confirming that Nrf2 activation in developing tubular cells causes a water reabsorption defect. These findings suggest that Nrf2 activity should be tightly controlled during development in order to maintain renal homeostasis. In addition, tissue-specific ablation of Nrf2 in Keap1-null mice might create useful animal models to uncover novel physiological functions of Nrf2. PMID:28233855

  17. The fine structure of sheep myocardial cells; sarcolemmal invaginations and the transverse tubular system.

    Science.gov (United States)

    SIMPSON, F O; OERTELIS, S J

    1962-01-01

    An electron microscope study of sheep myocardial cells has demonstrated the presence of a transverse tubular system, apparently forming a network across the cell at each Z band level. The walls of these tubules resemble the sarcolemma in consisting of two dense layers-plasma membrane and basement menbrane; continuity of the tubule walls with the sarcolemma can be seen when longitudinal sections of a cell are obtained between two subsarcolemmal myofibrils and at the same time perpendicular to the cell surface. The demonstration of communication between the lumen of the transverse tubular system and the extracellular space appears to be more definite in this study than in any work hitherto published. It provides anatomical evidence of a possible direct pathway for transmission of the activating impulse from the sarcolemma to the myofibril Z bands.

  18. Fabrication and characterization of a cathode-supported tubular solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chunhua; Liu, Renzhu; Wang, Shaorong; Wang, Zhenrong; Qian, Jiqin; Wen, Tinglian [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

    2009-07-15

    A cathode-supported tubular solid oxide fuel cell (CTSOFC) with the length of 6.0 cm and outside diameter of 1.0 cm has been successfully fabricated via dip-coating and co-sintering techniques. A crack-free electrolyte film with a thickness of {proportional_to}14 {mu}m was obtained by co-firing of cathode/cathode active layer/electrolyte/anode at 1250 C. The relative low densifying temperature for electrolyte was attributed to the large shrinkage of the green tubular which assisted the densification of electrolyte. The assembled cell was electrochemically characterized with humidified H{sub 2} as fuel and O{sub 2} as oxidant. The open circuit voltages (OCV) were 1.1, 1.08 and 1.06 V at 750, 800 and 850 C, respectively, with the maximum power densities of 157, 272 and 358 mW cm{sup -2} at corresponding temperatures. (author)

  19. A narrow open tubular column for high efficiency liquid chromatographic separation.

    Science.gov (United States)

    Chen, Huang; Yang, Yu; Qiao, Zhenzhen; Xiang, Piliang; Ren, Jiangtao; Meng, Yunzhu; Zhang, Kaiqi; Juan Lu, Joann; Liu, Shaorong

    2018-04-30

    We report a great feature of open tubular liquid chromatography when it is run using an extremely narrow (e.g., 2 μm inner diameter) open tubular column: more than 10 million plates per meter can be achieved in less than 10 min and under an elution pressure of ca. 20 bar. The column is coated with octadecylsilane and both isocratic and gradient separations are performed. We reveal a focusing effect that may be used to interpret the efficiency enhancement. We also demonstrate the feasibility of using this technique for separating complex peptide samples. This high-resolution and fast separation technique is promising and can lead to a powerful tool for trace sample analysis.

  20. A novel direct carbon fuel cell by approach of tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Zeng, Fanrong; Wang, Shaorong; Wen, Tinglian; Wen, Zhaoyin [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Inorganic Energy Materials and Power Source Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

    2010-01-15

    A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO-YSZ anode support tube, a NiO-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm{sup -2} at 850, 800, and 750 C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells. (author)

  1. Automation of Hessian-Based Tubularity Measure Response Function in 3D Biomedical Images.

    Science.gov (United States)

    Dzyubak, Oleksandr P; Ritman, Erik L

    2011-01-01

    The blood vessels and nerve trees consist of tubular objects interconnected into a complex tree- or web-like structure that has a range of structural scale 5 μm diameter capillaries to 3 cm aorta. This large-scale range presents two major problems; one is just making the measurements, and the other is the exponential increase of component numbers with decreasing scale. With the remarkable increase in the volume imaged by, and resolution of, modern day 3D imagers, it is almost impossible to make manual tracking of the complex multiscale parameters from those large image data sets. In addition, the manual tracking is quite subjective and unreliable. We propose a solution for automation of an adaptive nonsupervised system for tracking tubular objects based on multiscale framework and use of Hessian-based object shape detector incorporating National Library of Medicine Insight Segmentation and Registration Toolkit (ITK) image processing libraries.

  2. Cu removal and response mechanisms of periphytic biofilms in a tubular bioreactor.

    Science.gov (United States)

    Ma, Lan; Wang, Fengwu; Yu, Yuanchun; Liu, Junzhuo; Wu, Yonghong

    2018-01-01

    This work studied Cu removal and response mechanisms of periphytic biofilms in a tubular bioreactor. Periphytic biofilms immobilized in a tubular bioreactor were used to remove Cu from wastewater with different Cu concentrations. Results showed that periphytic biofilms had a high removal efficiency (max. 99%) at a hydraulic retention time (HRT) of 12h under initial Cu concentrations of 2.0 and 10.0mgL -1 . Periphyton quickly adapted to Cu stress by regulating the community composition. Species richness, evenness and carbon metabolic diversity of the periphytic community increased when exposed to Cu. Diatoms, green algae, and bacteria (Gammaproteobacteria and Bacteroidia) were the dominant microorganisms and responsible for Cu removal. This study indicates that periphytic biofilms are promising in Cu removal from wastewater due to their strong adaptation capacity to Cu toxicity and also provides valuable information for understanding the relationships between microbial communities and heavy metal stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The influence of angiotensin-converting enzyme inhibition on renal tubular function in progressive chronic nephropathy

    DEFF Research Database (Denmark)

    Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P

    1996-01-01

    The influence of angiotensin-converting enzyme (ACE) inhibition on renal tubular function in progressive chronic nephropathy was investigated in 69 patients by the lithium clearance (C(Li)) method. Studies were done repeatedly for up to 2 years during a controlled trial on the effect of enalapril...... on progression of renal failure. The pattern of proteinuria was followed over the first 9 months. At baseline, the glomerular filtration rate (GFR) was 5 to 68 mL/min. Absolute proximal tubular reabsorption rate of fluid (APR), estimated as the difference between GFR and C(Li), was 1 to 54 mL/min. Calculated...... in either treatment regimen was associated with a long-term slower progression of renal failure. Over 9 months, the 24-hour fractional clearance of albumin decreased in the ACE inhibitor group (P

  4. A case of Fanconi syndrome accompanied by crystal depositions in tubular cells in a patient with multiple myeloma

    Directory of Open Access Journals (Sweden)

    Do Hee Kim

    2014-06-01

    Full Text Available Fanconi syndrome (FS is a rare condition that is characterized by defects in the proximal tubular function. A 48-year-old woman was admitted for evaluation of proteinuria. The patient showed normal anion gap acidosis, normoglycemic glycosuria, hypophosphatemia, and hypouricemia. Thus, her condition was compatible with FS. The M peak was found behind the beta globulin region in urine protein electrophoresis. Upon bone marrow examination, we found that 24% of cells were CD138+ plasma cells with kappa restriction. From a kidney biopsy, we found crystalline inclusions within proximal tubular epithelial cells. Thereafter, she was diagnosed with FS accompanied by multiple myeloma. The patient received chemotherapy and autologous stem cell transplantation, and obtained very good partial hematologic response. However, proximal tubular dysfunction was persistent until 1 year after autologous stem cell transplantation. In short, we report a case of FS accompanied by multiple myeloma, demonstrating crystalline inclusion in proximal tubular cells on kidney biopsy.

  5. Engineering tubular bone using mesenchymal stem cell sheets and coral particles

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Wenxin [Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, No.229 North Taibai Road, Xi’an 710069 (China); Ma, Dongyang [Department of Oral and Maxillofacial Surgery, Lanzhou General Hospital, Lanzhou Command of PLA, BinHe 333 South Road, Lanzhou 730052 (China); Yan, Xingrong; Liu, Liangqi; Cui, Jihong; Xie, Xin; Li, Hongmin [Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, No.229 North Taibai Road, Xi’an 710069 (China); Chen, Fulin, E-mail: chenfl@nwu.edu.cn [Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, No.229 North Taibai Road, Xi’an 710069 (China)

    2013-04-19

    Highlights: • We developed a novel engineering strategy to solve the limitations of bone grafts. • We fabricated tubular constructs using cell sheets and coral particles. • The composite constructs showed high radiological density and compressive strength. • These characteristics were similar to those of native bone. -- Abstract: The development of bone tissue engineering has provided new solutions for bone defects. However, the cell-scaffold-based approaches currently in use have several limitations, including low cell seeding rates and poor bone formation capacity. In the present study, we developed a novel strategy to engineer bone grafts using mesenchymal stem cell sheets and coral particles. Rabbit bone marrow mesenchymal stem cells were continuously cultured to form a cell sheet with osteogenic potential and coral particles were integrated into the sheet. The composite sheet was then wrapped around a cylindrical mandrel to fabricate a tubular construct. The resultant tubular construct was cultured in a spinner-flask bioreactor and subsequently implanted into a subcutaneous pocket in a nude mouse for assessment of its histological characteristics, radiological density and mechanical property. A similar construct assembled from a cell sheet alone acted as a control. In vitro observations demonstrated that the composite construct maintained its tubular shape, and exhibited higher radiological density, compressive strength and greater extracellular matrix deposition than did the control construct. In vivo experiments further revealed that new bone formed ectopically on the composite constructs, so that the 8-week explants of the composite sheets displayed radiological density similar to that of native bone. These results indicate that the strategy of using a combination of a cell sheet and coral particles has great potential for bone tissue engineering and repairing bone defects.

  6. Probabilistic Fatigue Analysis of Jacket Support Structures for Offshore Wind Turbines Exemplified on Tubular Joints

    OpenAIRE

    Kelma, Sebastian; Schaumann, Peter

    2015-01-01

    The design of offshore wind turbines is usually based on the semi-probabilistic safety concept. Using probabilistic methods, the aim is to find an advanced structural design of OWTs in order to improve safety and reduce costs. The probabilistic design is exemplified on tubular joints of a jacket substructure. Loads and resistance are considered by their respective probability distributions. Time series of loads are generated by fully-coupled numerical simulation of the offshore wind turbine. ...

  7. Clinical profile and outcome of renal tubular disorders in children: A single center experience

    Directory of Open Access Journals (Sweden)

    B Vijay Kiran

    2014-01-01

    Full Text Available Tubular disorders form a significant proportion of pediatric kidney diseases and are an important differential diagnosis of failure to thrive (FTT in children. Data regarding their outcome is scarce from India. We evaluated the clinical profile of these children and studied the outcome in terms of their growth and renal failure. This is a retrospective longitudinal study of all children with renal tubular disorders attending a tertiary care pediatric nephrology center from 2005 to 2010. Growth and renal outcomes were assessed by Z scores and estimated glomerular filtration rate at diagnosis and. The common disorders encountered were distal renal tubular acidosis (d-RTA (44%, Bartter-like (Bartter′s and Gitelman syndromes (22% followed by hereditary Fanconi syndrome (cystinosis and idiopathic Fanconi syndrome (13% and few cases of nephrogenic diabetes insipidus, hypophosphatemic rickets and idiopathic hypercalciuria. Male: female ratio was 1.22. The median age at diagnosis was 1.5 (range 0.13-11 years. Growth failure was the presenting feature in 86% of children followed by polyuria (60% and bone deformities (47%. In 60% of children with hereditary Fanconi syndrome, nephropathic cystinosis was diagnosed, all of whom progressed to stage III chronic kidney disease (CKD within 3.41 ± 1.42 years. With appropriate therapy, catch-up growth was noted in d-RTA and Bartter syndrome. Renal tubular disorders usually present with FTT. d-RTA is the most common etiology followed by Bartter-like syndrome. Renal function is preserved in all these disorders except for nephropathic cystinosis, who ultimately progressed to CKD. With appropriate and inexpensive therapy, these children do grow well.

  8. A miniature implantable coil that can be wrapped around a tubular organ within the human body

    Science.gov (United States)

    Mao, Shitong; Wang, Hao; Mao, Zhi-Hong; Sun, Mingui

    2018-05-01

    There are many tubular or rod-shaped organs and tissues within the human body. A miniature medical implant that wraps around such a biological structure can monitor or modulate its function. In order to provide the wrap-around implant with power, a solenoidal coil coupled wirelessly with a planar coil outside the human body can be used. Unfortunately, there is a serious practical problem that this configuration cannot be realized easily because the implantable solenoidal coil cannot be positioned around the tubular biological structure unless either the structure or the coil is cut and reconnected, which is impermissible in most cases. In addition, when a planner exterior coil is used for wireless power transfer and communication, its maximum magnetic coupling with the implanted solenoidal coil is achieved when the tubular structure is perpendicular to the surface of the body. However, in human anatomy, most tubular/rod structures are oriented horizontally. In order to solve these problems, we present a new flexible coil for the class of wrapped-around implantable devices. Our multilayer coil has specially designed windings in cross patterns. The new coil can be made conveniently in high precision at low cost on a flat substrate using the same technology for making the flexible multilayer printed circuit boards along with miniature sensors and electronic circuits. This allows the implant to be made in a flat form and then wrapped around the biostructure during surgery. We present the design of this new coil, perform theoretical analysis with respect to its wireless power transfer efficiency, discuss the effects of coil parameters, and conduct experiments using constructed miniature prototypes. Our results confirm the validity of the new coil.

  9. Preputial reconstruction and tubularized incised plate urethroplasty in proximal hypospadias with ventral penile curvature

    OpenAIRE

    Bhat, Amilal; Gandhi, Ajay; Saxena, Gajendra; Choudhary, Gautam Ram

    2010-01-01

    Aims : Objective of this study was to assess the feasibility and results of preputial reconstruction and tubularized incised plate urethroplasty (TIP) in patients of proximal hypospadias with ventral penile curvature. Materials and Methods : Twenty-seven patients of proximal hypospadias who underwent preputioplasty with TIP were evaluated retrospectively. Ventral curvature was corrected by mobilization of the urethral plate with the corpus spongiosum and the proximal urethra; dorsal plica...

  10. Tubular manipulators: a new concept for intracochlear positioning of an auditory prosthesis

    Directory of Open Access Journals (Sweden)

    Rau Thomas S.

    2015-09-01

    Full Text Available The aim of this study was to investigate the applicability of tubular manipulators as an actuator mechanism for intracochlear positioning of the electrode array (EA of a cochlear implant (CI. This is motivated by the vision of an atraumatic insertion of the EA into the inner ear (cochlea without any damage to the intracochlear structures in combination with a well-defined final position. To realize this, an actuator mechanism is required which allows consideration of the patient-specific anatomy. We propose a tubular manipulator for this task. It consists of three concentric tubes: A straight outer tube serves as a guiding sleeve to enter the inner ear (cochlea and two additional telescoping, superelastic, helically precurved tubes. By selecting helical tube parameters of both tubes prior insertion, a patient-specific curling behaviour of the tubular manipulator can be achieved. For preliminary investigation, segmentation and skeletonization of 5 human scala tympani were performed to determine their centrelines. These centrelines were considered as individual ideal insertion paths. An optimization algorithm was developed to identify suitable tube set parameters (curvature, diameter, length, torsion, stiffness as well as configuration parameters (translation and rotation of the 2 inner tubes. Different error values describing the deviation of the shape of the tubes with respect to the insertion path were used to quantify the optimization results. In all cases tube set parameters for a final position within the cochlea were found, while keeping the maximum error below 1mm. These preliminary results are promising in terms of the potential applicability of tubular manipulators for positioning auditory prosthesis inside the scala tympani of the inner ear.

  11. Renal tubular dysfunction in pediatric patients with beta-thalassemia major

    Directory of Open Access Journals (Sweden)

    Ali Ahmadzadeh

    2011-01-01

    Full Text Available To evaluate the prevalence of renal tubular dysfunction in children with β-thalassemia (β-T major, we studied the glomerular and tubular function in 140 children with β-T major and compared them to a healthy control group at our center from May 2007 to April 2008. Fresh first morning samples were collected from each patient and analyzed for sodium, potassium, calcium (Ca, protein, uric acid (UA, creatinine (Cr, urine osmolality and urinary N-acetyl-β-D-glucosaminidase (UNAG activity. Blood samples were also collected for complete blood count, blood urea nitrogen (BUN, fasting blood sugar, serum creatinine (SCr, electrolytes, and ferritin before transfusion. Among the study patients, 72 were males, and the mean age was 11.5 (ranging 7-16 years. SCr levels were all within normal limits and all of them had normal glomerular filtration rate (GFR. The mean UNAG was 17.8 IU/L in the study patients (normal 0.15-11.5 IU/L and 3.2 IU/L in the control group (P 0.21 (P = 0.006. Nine (6.4% thalassemic patients with a mean age of 12 years had proteinuria (Upr/UCr > 0.2. Sixty-nine (49.3% out of the 140 patients and 45 (65.2% of the patients having UNAG had uricosuria also (UUA/UCr > 0.26. Ten (7% patients had microscopic hematuria and 10 (7% patients with a mean age of 13.5 years had glucosuria or diabetes mellitus. We conclude that tubular dysfunction is a relative common complication of the β-T major; UNAG and its index are the best to detect renal tubular dysfunction in these patients. Currently, periodic measurement of UCa/UCr and UUA/UCr ratios as well as urinalysis are recommended.

  12. Effect of Processing Parameters on Pore Structure and Thickness of Anodic Aluminum Oxide (AAO) Tubular Membranes

    OpenAIRE

    Belwalkar, A.; Grasing, E.; Van Geertruyden, W.; Huang, Z.; Misiolek, W.Z.

    2008-01-01

    Nanoporous anodic aluminum oxide (AAO) tubular membranes were fabricated from aluminum alloy tubes in sulfuric and oxalic acid electrolytes using a two-step anodization process. The membranes were investigated for characteristics such as pore size, interpore distance and thickness by varying applied voltage and electrolyte concentration. Morphology of the membranes was examined using light optical and scanning electron microscopy and characterized using ImageJ software. Results showed that me...

  13. Experimental Investigation of Chatter Dynamics in Thin-walled Tubular Parts Turning

    OpenAIRE

    GERASIMENKO, Artem; GUSKOV, Mikhail; LORONG, Philippe; DUCHEMIN, Jérôme; GOUSKOV, Alexander

    2016-01-01

    Chatter prediction is nowadays frequently carried out for machining operations involving deformable parts or tools. These analyses are commonly based on the uncoupled elements of the system: frequency response of the deformable parts under non-rotating conditions and cutting law. The present investigation puts forward the dynamics of a thin-walled tubular part during straight axial turning undergoing chatter instability. Studied system’s peculiarities include quasi-static nominal cutting cond...

  14. Expanding the histologic spectrum of mucinous tubular and spindle cell carcinoma of the kidney.

    Science.gov (United States)

    Fine, Samson W; Argani, Pedram; DeMarzo, Angelo M; Delahunt, Brett; Sebo, Thomas J; Reuter, Victor E; Epstein, Jonathan I

    2006-12-01

    Mucinous tubular and spindle cell carcinomas (MTSCs) are polymorphic neoplasms characterized by small, elongated tubules lined by cuboidal cells and/or cords of spindled cells separated by pale mucinous stroma. Nonclassic morphologic variants and features of MTSC have not been well studied. We identified 17 previously unreported MTSCs from Surgical Pathology and consultative files of the authors and their respective institutions and studied their morphologic features. A total of 10/17 cases were considered "classic," as described above, with 5/10 showing at least focal (20% to 50%) tubular predominance without apparent mucinous matrix. Alcian blue staining revealed abundant (>50%) mucin in all classic cases. Seven of 17 MTSCs were classified as "mucin-poor," with little to no extracellular mucin appreciable by hematoxylin and eosin. Four of these cases showed equal tubular and spindled morphology, 2 cases showed spindle cell predominance (70%; 95%), and 1 case showed tubular predominance (90%). In 5/7 mucin-poor cases, staining for Alcian blue revealed scant (<10%) mucin in cellular areas with the other 2 cases having 30% mucin. Unusual histologic features identified in the 17 cases were: foamy macrophages (n=8), papillations/well formed papillae (n=6/n=1), focal clear cells in tubules (n=3), necrosis (n=3), oncocytic tubules (n=2; 40%, 5%), numerous small vacuoles (n=2), heterotopic bone (n=1), psammomatous calcification (n=1), and nodular growth with lymphocytic cuffing (n=1). An exceptional case contained a well-circumscribed, HMB45-positive angiomyolipoma within the MTSC. MTSCs may be "mucin-poor" and show a marked predominance of either of its principal morphologic components, which coupled with the presence of other unusual features such as clear cells, papillations, foamy macrophages, and necrosis, may mimic other forms of renal cell carcinoma. Pathologists must be aware of the spectrum of histologic findings within MTSCs to ensure their accurate diagnosis.

  15. A miniature implantable coil that can be wrapped around a tubular organ within the human body

    Directory of Open Access Journals (Sweden)

    Shitong Mao

    2018-05-01

    Full Text Available There are many tubular or rod-shaped organs and tissues within the human body. A miniature medical implant that wraps around such a biological structure can monitor or modulate its function. In order to provide the wrap-around implant with power, a solenoidal coil coupled wirelessly with a planar coil outside the human body can be used. Unfortunately, there is a serious practical problem that this configuration cannot be realized easily because the implantable solenoidal coil cannot be positioned around the tubular biological structure unless either the structure or the coil is cut and reconnected, which is impermissible in most cases. In addition, when a planner exterior coil is used for wireless power transfer and communication, its maximum magnetic coupling with the implanted solenoidal coil is achieved when the tubular structure is perpendicular to the surface of the body. However, in human anatomy, most tubular/rod structures are oriented horizontally. In order to solve these problems, we present a new flexible coil for the class of wrapped-around implantable devices. Our multilayer coil has specially designed windings in cross patterns. The new coil can be made conveniently in high precision at low cost on a flat substrate using the same technology for making the flexible multilayer printed circuit boards along with miniature sensors and electronic circuits. This allows the implant to be made in a flat form and then wrapped around the biostructure during surgery. We present the design of this new coil, perform theoretical analysis with respect to its wireless power transfer efficiency, discuss the effects of coil parameters, and conduct experiments using constructed miniature prototypes. Our results confirm the validity of the new coil.

  16. Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model.

    Directory of Open Access Journals (Sweden)

    Tokiko Ishida

    Full Text Available The pathogenesis of renal impairment in chronic liver diseases (CLDs has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy, autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the

  17. Increase of efficiency of plant materials heat treatment in tubular reactors

    Directory of Open Access Journals (Sweden)

    A. V. Golubkovich

    2016-01-01

    Full Text Available In agriculture products of pyrolysis of plant materials in the form of waste of the main production can be applied as a source of heat and electric power. Besides, their use prevents ecological pollution of the soil and the atmosphere. Pyrolysis plants can be used for work with tubular reactors anywhere. Due to them farmers can dry grain, using waste heat of diesel generators, heatgenerators, boiler plants and receiving thus gaseous products, liquid and firm fractions. A technology based on cyclic and continuous plant mass movement by a piston in a pipe from a loading site to a place of unloading of a firm phase consistently through cameras of drying, pyrolysis, condensation of gaseous products. Exhaust furnace gases with a temperature up to 600 degrees Celsius are given countercurrent material movement from a power equipment. The gaseous, liquid and firm products from the pyrolysis camera are used for heat and electric power generation. Calculation of parameters of subdrying and pyrolysis cameras is necessary for effective and steady operation of the tubular reactor. The authors determined the speed of raw materials movement, and also duration of drying and pyrolysis in working chambers. An analysis of a simplified mathematical model of process was confirmed with results of experiments. Models of heat treatment of wet plant materials in tubular reactors are worked out on a basis of equality of speeds of material movement in the reactor and distribution of a temperature front in material on radius. The authors defined estimated characteristic for determination of tubular reactor productivity and size of heat, required for drying and pyrolysis.

  18. A novel tubular linear motor equipped with radially anisotropic NdFeB ring magnets

    International Nuclear Information System (INIS)

    Hor, P.J.

    1998-01-01

    The paper describes the design synthesis and optimisation of a novel tubular linear motor employing radially magnetised anisotropic ring magnets. Design issues, related to optimising the dimensions for maximum acceleration capability, minimum cogging force and low harmonic distortion in the emf waveform, are discussed. The influence of inhomogeneities in the magnets on the performance of a prototype motor is discussed, and its dynamic performance is validated experimentally against a typical target specification for automated high-speed manufacturing applications. (orig.)

  19. Engineering tubular bone using mesenchymal stem cell sheets and coral particles

    International Nuclear Information System (INIS)

    Geng, Wenxin; Ma, Dongyang; Yan, Xingrong; Liu, Liangqi; Cui, Jihong; Xie, Xin; Li, Hongmin; Chen, Fulin

    2013-01-01

    Highlights: • We developed a novel engineering strategy to solve the limitations of bone grafts. • We fabricated tubular constructs using cell sheets and coral particles. • The composite constructs showed high radiological density and compressive strength. • These characteristics were similar to those of native bone. -- Abstract: The development of bone tissue engineering has provided new solutions for bone defects. However, the cell-scaffold-based approaches currently in use have several limitations, including low cell seeding rates and poor bone formation capacity. In the present study, we developed a novel strategy to engineer bone grafts using mesenchymal stem cell sheets and coral particles. Rabbit bone marrow mesenchymal stem cells were continuously cultured to form a cell sheet with osteogenic potential and coral particles were integrated into the sheet. The composite sheet was then wrapped around a cylindrical mandrel to fabricate a tubular construct. The resultant tubular construct was cultured in a spinner-flask bioreactor and subsequently implanted into a subcutaneous pocket in a nude mouse for assessment of its histological characteristics, radiological density and mechanical property. A similar construct assembled from a cell sheet alone acted as a control. In vitro observations demonstrated that the composite construct maintained its tubular shape, and exhibited higher radiological density, compressive strength and greater extracellular matrix deposition than did the control construct. In vivo experiments further revealed that new bone formed ectopically on the composite constructs, so that the 8-week explants of the composite sheets displayed radiological density similar to that of native bone. These results indicate that the strategy of using a combination of a cell sheet and coral particles has great potential for bone tissue engineering and repairing bone defects

  20. The Effect of non-Newtonian Behavior of Fluid on the Tubular Reactor Performance and Studying Different Variables in Relation to the Degree of Conversion

    Directory of Open Access Journals (Sweden)

    Keivan Shayesteh

    2015-02-01

    Full Text Available In tubular reactors, there are different parameters which can affect the degree of conversion. The type of fluid motion and velocity profile of substances in the reactor are of most central measures. Different rheological models can be employed to study the behavior of fluids; power law model is one of the most commonly used models. In this study, the rheological behaviour of polymerization reaction of methyl methacrylate was examined. Due to the similarity function of tubular and batch reactors, the number of test tubes are used to prepare the solution. After preparation of the reactor solution, the n value of power law model was estimated within the span of 0.3492 to 0.9889 by curve fitting. Employing these rheological data, a reactor has been designed. Moreover, the effects of parameters such as reaction temperature, initiator wt%, the concentration of monomer and reactor’s radius on the degree of conversion have been studied. The obtained results in the research indicate a direct proportionality of conversion with the reaction temperature, initiator wt% and the concentration of monomer and also an inverse proportionality of conversion with reactor’s radius. Finally, the amount of conversion was obtained equal to 56.47% and according to its laboratory proportion which was 55.88% we have reached the conclusion that the modeling duly undertaken is applicable and valid.

  1. Preparation and characterization of coaxial halloysite/polypyrrole tubular nanocomposites for electrochemical energy storage

    International Nuclear Information System (INIS)

    Yang Chao; Liu Peng; Zhao Yongqing

    2010-01-01

    Halloysite nanotubes/polypyrrole (HNTs/PPy) nanocomposites with coaxial tubular morphology for use as electrode materials for supercapacitors were synthesized by the in situ chemical oxidative polymerization method based on self-assembled monolayer amine-functionalized HNTs. The HNTs/PPy coaxial tubular nanocomposites were characterized with transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), electrical conductivity measurement at different temperatures, cyclic voltammetry (CV), and galvanostatic charge-discharge measurements. The coaxial tubular nanocomposites showed their greatest conductivity at room temperature and a weak temperature dependence of the conductivity from 298 K to 423 K. A maximum discharge capacity of 522 F/g after correcting for the weight percent of the PPy phase at a current density of 5 mA cm -2 in a 0.5 M Na 2 SO 4 electrolyte could be achieved in a half-cell setup configuration for the HNTs/PPy composites electrode, suggesting its potential application in electrode materials for electrochemical capacitors.

  2. Preparation and characterization of coaxial halloysite/polypyrrole tubular nanocomposites for electrochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Yang Chao [State Key Laboratory of Applied Organic Chemistry and Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000 (China); Liu Peng, E-mail: pliu@lzu.edu.c [State Key Laboratory of Applied Organic Chemistry and Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000 (China); Zhao Yongqing [State Key Laboratory of Applied Organic Chemistry and Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000 (China)

    2010-09-01

    Halloysite nanotubes/polypyrrole (HNTs/PPy) nanocomposites with coaxial tubular morphology for use as electrode materials for supercapacitors were synthesized by the in situ chemical oxidative polymerization method based on self-assembled monolayer amine-functionalized HNTs. The HNTs/PPy coaxial tubular nanocomposites were characterized with transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), electrical conductivity measurement at different temperatures, cyclic voltammetry (CV), and galvanostatic charge-discharge measurements. The coaxial tubular nanocomposites showed their greatest conductivity at room temperature and a weak temperature dependence of the conductivity from 298 K to 423 K. A maximum discharge capacity of 522 F/g after correcting for the weight percent of the PPy phase at a current density of 5 mA cm{sup -2} in a 0.5 M Na{sub 2}SO{sub 4} electrolyte could be achieved in a half-cell setup configuration for the HNTs/PPy composites electrode, suggesting its potential application in electrode materials for electrochemical capacitors.

  3. Additive Manufacturing of Patient-Customizable Scaffolds for Tubular Tissues Using the Melt-Drawing Method.

    Science.gov (United States)

    Tan, Yu Jun; Tan, Xipeng; Yeong, Wai Yee; Tor, Shu Beng

    2016-11-03

    Polymeric fibrous scaffolds for guiding cell growth are designed to be potentially used for the tissue engineering (TE) of tubular organs including esophagi, blood vessels, tracheas, etc. Tubular scaffolds were fabricated via melt-drawing of highly elastic poly(l-lactide-co-ε-caprolactone) (PLC) fibers layer-by-layer on a cylindrical mandrel. The diameter and length of the scaffolds are customizable via 3D printing of the mandrel. Thickness of the scaffolds was varied by changing the number of layers of the melt-drawing process. The morphology and tensile properties of the PLC fibers were investigated. The fibers were highly aligned with a uniform diameter. Their diameters and tensile properties were tunable by varying the melt-drawing speeds. These tailorable topographies and tensile properties show that the additive-based scaffold fabrication technique is customizable at the micro- and macro-scale for different tubular tissues. The merits of these scaffolds in TE were further shown by the finding that myoblast and fibroblast cells seeded onto the scaffolds in vitro showed appropriate cell proliferation and distribution. Human mesenchymal stem cells (hMSCs) differentiated to smooth muscle lineage on the microfibrous scaffolds in the absence of soluble induction factors, showing cellular shape modulation and scaffold elasticity may encourage the myogenic differentiation of stem cells.

  4. Tubular foreign body or stent: safe retrieval or repositioning using the coaxial snare technique

    International Nuclear Information System (INIS)

    Seong, Chang Kyu; Kim, Yong Joo; Chung, Jin Wook; Kim, Seung Hyup; Han, Joon Koo; Kim, Hyun Beom; Park, Jae Hyung

    2002-01-01

    To evaluate the utility and advantages of the coaxial snare technique in the retrieval of tubular foreign bodies. Using the coaxial snare technique, we attempted to retrieve tubular foreign bodies present in seven patients. The bodies were either stents which were malpositioned or had migrated from their correct position in the vascular system (n=2), a fragmented venous introducer sheath (n=1), fragmented drainage catheters in the biliary tree (n=2), or fractured external drainage catheters in the urinary tract (n=2). After passing a guidewire and/or a dilator through the lumina of these foreign bodies, we introduced a loop snare over the guidewire or dilator, thus capturing and retrieving them. In all cases, it was possible to retrieve or reposition the various items, using a minimum-sized introducer sheath or a tract. No folding was involved. In no case were surgical procedures required, and no complications were encountered. The coaxial snare technique, an application of the loop snare technique, is a useful and safe method for the retrieval of tubular foreign bodies, and one which involves minimal injury to the patient

  5. Tubularized Penile-Flap Urethroplasty Using a Fasciocutaneous Random Pedicled Flap for Recurrent Anterior Urethral Stricture

    Directory of Open Access Journals (Sweden)

    Yong Jig Lee

    2012-05-01

    Full Text Available This report describes the use of a tubularized random flap for the curative treatment of recurrent anterior urethral stricture. Under the condition of pendulous lithotomy and suprapubic cystostomy, the urethral stricture was removed via a midline ventral penile incision followed by elevation of the flap and insertion of an 18-Fr catheter. Subcutaneous buried interrupted sutures were used to reapproximate the waterproof tubularized neourethra and to coapt with the neourethra and each stump of the urethra, first proximally and then distally. The defect of the penile shaft was covered by advancement of the surrounding scrotal flap. The indwelling catheter was maintained for 21 days. A 9 month postoperative cystoscopy showed no flap necrosis, no mechanical stricture, and no hair growth on the lumen of the neourethra. The patient showed no voiding discomfort 6 months after the operation. The advantages of this procedure are the lack of need for microsurgery, shortening of admission, the use of only spinal anesthesia (no general anesthesia, and a relatively short operative time. The tubularized unilateral penile fasciocutaneous flap should be considered an option for initial flap urethroplasty as a curative technique.

  6. Tubular immunostimulating complex based on cucumarioside A2-2 and monogalactosyldiacylglycerol from marine macrophytes

    Directory of Open Access Journals (Sweden)

    Vorobyeva Natalia S

    2011-09-01

    Full Text Available Abstract Background There is an urgent need to develop safe and effective adjuvants for the new generation of subunit vaccines. We developed the tubular immunostimulating complex (TI-complex as a new nanoparticulate antigen delivery system. The morphology and composition of TI-complexes principally differ from the known vesicular immunostimulating complexes (ISCOMs. However, methodology for the preparation of TI-complexes has suffered a number of shortcomings. The aim of the present work was to obtain an antigen carrier consisting of triterpene glycosides from Cucumaria japonica, cholesterol, and monogalactosyldiacylglycerol from marine macrophytes with reproducible properties and high adjuvant activity. Results The cucumarioside A2-2 - cholesterol - MGalDG ratio of 6:2:4 (by weight was found to provide the most effective formation of TI-complexes and the minimum hemolytic activity in vitro. Tubules of TI-complexes have an outer diameter of about 16 nm, an inner diameter of 6 nm, and a length of 500 nm. A significant dilution by the buffer gradually destroyed the tubular nanoparticles. The TI-complex was able to increase the immunogenicity of the protein antigens from Yersinia pseudotuberculosis by three to four times. Conclusions We propose an optimized methodology for the preparation of homogeneous TI-complexes containing only tubular particles, which would achieve reproducible immunization results. We suggest that the elaborated TI-complexes apply as a universal delivery system for different subunit antigens within anti-infectious vaccines and enhance their economic efficacy and safety.

  7. Treatment of wastewater containing phenol using a tubular ceramic membrane bioreactor.

    Science.gov (United States)

    Ersu, C B; Ong, S K

    2008-02-01

    The performance of a membrane bioreactor (MBR) with a tubular ceramic membrane for phenol removal was evaluated under varying hydraulic retention times (HRT) and a fixed sludge residence time (SRT) of 30 days. The tubular ceramic membrane was operated with a mode of 15 minutes of filtration followed by 15 seconds of permeate backwashing at a flux of 250 l m(-2)hr(-1) along with an extended backwashing of 30 seconds every 3 hours of operation, which maintained the transmembrane pressure (TMP) below 100 kPa. Using a simulated municipal wastewater with varying phenol concentrations, the chemical oxygen demand (COD) and phenol removals observed were greater than 88% with excellent suspended solids (SS) removal of 100% at low phenol concentrations (approx. 100 mg l(-1) of phenol). Step increases in phenol concentration showed that inhibition was observed between 600 to 800 mg l(-1) of phenol with decreased sludge production rate, mixed liquor suspended solids (MLSS) concentration, and removal performance. The sludge volume index (SVI) of the biomass increased to about 450 ml g(-1) for a phenol input concentration of 800 mg l(-1). When the phenol concentration was decreased to 100 mg l(-1), the ceramic tubular MBR was found to recover rapidly indicating that the MBR is a robust system retaining most of the biomass. Experimental runs using wastewater containing phenol indicated that the MBR can be operated safely without upsets for concentrations up to 600 mg l(-1) of phenol at 2-4 hours HRT and 30 days SRT.

  8. Uric Acid Induces Renal Inflammation via Activating Tubular NF-κB Signaling Pathway

    Science.gov (United States)

    Zhou, Yang; Fang, Li; Jiang, Lei; Wen, Ping; Cao, Hongdi; He, Weichun; Dai, Chunsun; Yang, Junwei

    2012-01-01

    Inflammation is a pathologic feature of hyperuricemia in clinical settings. However, the underlying mechanism remains unknown. Here, infiltration of T cells and macrophages were significantly increased in hyperuricemia mice kidneys. This infiltration of inflammatory cells was accompanied by an up-regulation of TNF-α, MCP-1 and RANTES expression. Further, infiltration was largely located in tubular interstitial spaces, suggesting a role for tubular cells in hyperuricemia-induced inflammation. In cultured tubular epithelial cells (NRK-52E), uric acid, probably transported via urate transporter, induced TNF-α, MCP-1 and RANTES mRNA as well as RANTES protein expression. Culture media of NRK-52E cells incubated with uric acid showed a chemo-attractive ability to recruit macrophage. Moreover uric acid activated NF-κB signaling. The uric acid-induced up-regulation of RANTES was blocked by SN 50, a specific NF-κB inhibitor. Activation of NF-κB signaling was also observed in tubule of hyperuricemia mice. These results suggest that uric acid induces renal inflammation via activation of NF-κB signaling. PMID:22761883

  9. The Association of Albuminuria With Tubular Reabsorption of Uric Acid: Results From a General Population Cohort

    Science.gov (United States)

    Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

    2014-01-01

    Background Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and Results Included were 7688 participants of the PREVEND Study, an observational, general population‐based cohort study. Linear regression analyses were used to test associations of baseline albuminuria with baseline serum uric acid concentration and tubular uric acid reabsorption (calculated as [100−fractional uric acid excretion]%). Cox regression analyses were used to study the association of baseline serum uric acid and albuminuria with incident cardiovascular morbidity and mortality. In cross‐sectional analyses, albuminuria was associated positively with serum uric acid concentration, both crude and after adjustment for potential confounders (both Puric acid reabsorption, again both crude and after adjustment for potential confounders (both Puric acid were associated with incident cardiovascular events (Hazard Ratios 1.09 [1.03 to 1.17], P=0.01 and 1.19 [1.09 to 1.30], Puric acid being less predictive for cardiovascular morbidity and mortality in the presence of high albuminuria and vice versa. Conclusions Albuminuria is strongly associated with tubular uric acid reabsorption, and consequently with serum uric acid concentration. This phenomenon may explain in part why albuminuria is associated with cardiovascular outcome. PMID:24772520

  10. Exosome production and its regulation of EGFR during wound healing in renal tubular cells.

    Science.gov (United States)

    Zhou, Xiangjun; Zhang, Wei; Yao, Qisheng; Zhang, Hao; Dong, Guie; Zhang, Ming; Liu, Yutao; Chen, Jian-Kang; Dong, Zheng

    2017-06-01

    Kidney repair following injury involves the reconstitution of a structurally and functionally intact tubular epithelium. Growth factors and their receptors, such as EGFR, are important in the repair of renal tubules. Exosomes are cell-produced small (~100 nm in diameter) vesicles that contain and transfer proteins, lipids, RNAs, and DNAs between cells. In this study, we examined the relationship between exosome production and EGFR activation and the potential role of exosome in wound healing. EGFR activation occurred shortly after scratch wounding in renal tubular cells. Wound repair after scratching was significantly promoted by EGF and suppressed by EGFR inhibitor gefitinib. Interestingly, scratch wounding induced a significant increase of exosome production. The exosome production was decreased by EGF and increased by gefitinib, suggesting a suppressive role of EGFR signaling in exosome production. Conversely, inhibition of exosome release by GW4869 and manumycin A markedly increased EGFR activation and promoted wound healing. Moreover, exosomes derived from scratch-wounding cells could inhibit wound healing. Collectively, the results indicate that wound healing in renal tubular cells is associated with EGFR activation and exosome production. Although EGFR activation promotes wound healing, released exosomes may antagonize EGFR activation and wound healing. Copyright © 2017 the American Physiological Society.

  11. The Design and Performance Evaluation of Hydroformed Tubular Torsion Beam Axle

    Science.gov (United States)

    Kim, Jaehyun; Oh, Jinho; Choi, Hanho

    2010-06-01

    Suspensions for vehicles are structural devices used for suspending a vehicle body and absorbing shocks from the road. Thus, the suspensions must be designed such that they can attenuate shocks from a road and make passengers feel comfortable despite the shocks, and improve steering stability, determined by the ground contact force of tires during running of vehicles. Another important factor to be considered while designing suspensions is that the suspensions must maintain desired stiffness and desired durability despite the repeated application of shocks from roads thereto. The present relates, in general, to a tubular torsion beam for rear suspensions of vehicles and a manufacturing method thereof and, more particularly, to the provision of tubular torsion beams having excellent roll stiffness and excellent roll strength, produced through hydroforming. The hydroforming technology has a lot of benefit which is shape accuracy, good durability caused by compressive pressure, and good forming quality. In this study, the performance evaluation of the hydroformed tubular torsion beam axle is evaluated.

  12. Endo-lysosomal dysfunction in human proximal tubular epithelial cells deficient for lysosomal cystine transporter cystinosin.

    Directory of Open Access Journals (Sweden)

    Ekaterina A Ivanova

    Full Text Available Nephropathic cystinosis is a lysosomal storage disorder caused by mutations in the CTNS gene encoding cystine transporter cystinosin that results in accumulation of amino acid cystine in the lysosomes throughout the body and especially affects kidneys. Early manifestations of the disease include renal Fanconi syndrome, a generalized proximal tubular dysfunction. Current therapy of cystinosis is based on cystine-lowering drug cysteamine that postpones the disease progression but offers no cure for the Fanconi syndrome. We studied the mechanisms of impaired reabsorption in human proximal tubular epithelial cells (PTEC deficient for cystinosin and investigated the endo-lysosomal compartments of cystinosin-deficient PTEC by means of light and electron microscopy. We demonstrate that cystinosin-deficient cells had abnormal shape and distribution of the endo-lysosomal compartments and impaired endocytosis, with decreased surface expression of multiligand receptors and delayed lysosomal cargo processing. Treatment with cysteamine improved surface expression and lysosomal cargo processing but did not lead to a complete restoration and had no effect on the abnormal morphology of endo-lysosomal compartments. The obtained results improve our understanding of the mechanism of proximal tubular dysfunction in cystinosis and indicate that impaired protein reabsorption can, at least partially, be explained by abnormal trafficking of endosomal vesicles.

  13. A Mathematical Model of Renal Blood Distribution Coupling TGF, MR and Tubular System

    Institute of Scientific and Technical Information of China (English)

    GAO Ci-xiu; YANG Lin; WANG Ke-qiang; XU Shi-xiong; DAI Pei-dong

    2009-01-01

    Objective:To investigate the relationship between renal blood distribution and the physiological activities of the kidney. Methods:A mathematical model is developed based on Hagan-Poiseuille law and mass transport, coupling mechanics of myogenic response (MR), tubuloglomerular feedback (TGF) and the tubular system in the renal medulla. The model parameters, including the permeability coefficients, the vascular lumen radius and the solute concentration at the inlet of the tubes, are derived from the experimental results. Simulations of the blood and water flow in the loop of Henel, the collecting duct and vas rectum, are carried out by the model of the tubular system in the renal medulla, based on conservations of water and solutes for transmural transport. Then the tubular model is coupled with MR and TGF mechanics. Results:The results predict the dynamics of renal autoregulation on its blood pressure and flow,and the distributions are 88.5% in the cortex, 10.3% in the medulla, and 1.2% at papilla,respectively. The fluid flow and solute concentrations along the tubules and vasa recta are obtained. Conclusion:The present model could assess renal functions qualitatively and quantitatively and provide a methodological approach for clinical research.

  14. Rocket-inspired tubular catalytic microjets with grating-structured walls as guiding empennages.

    Science.gov (United States)

    Huang, Gaoshan; Wang, Jiyuan; Liu, Zhaoqian; Zhou, Dekai; Tian, Ziao; Xu, Borui; Li, Longqiu; Mei, Yongfeng

    2017-12-07

    Controllable locomotion in the micro-/nanoscale is challenging and attracts increasing research interest. Tubular microjets self-propelled by microbubbles are intensively investigated due to their high energy conversion efficiency, but the imperfection of the tubular geometry makes it harder to realize linear motion. Inspired by the macro rocket, we designed a tubular microjet with a grating-structured wall which mimics the guiding empennage of the macro rocket, and we found that the fluid can be effectively guided by the grooves. Both theoretical simulation and experimental work have been carried out, and the obtained results demonstrate that the stability margin of the grating-structured microjet can be enhanced. Compared with microjets with smooth walls, the structured microjets show an enhanced ability of moving linearly. In 10% H 2 O 2 , only 20% of the smooth microjets demonstrate linear trajectories, while 80% of the grating-structured microjets keep moving straight. The grating-structured microjet can maintain linear motion under external disturbance. We further propose to increase the stability by introducing a helical grating structure.

  15. Renal tubular dysfunction nephrocalcinosis in a patient with BetaThalassemia Minor

    International Nuclear Information System (INIS)

    Prabahar, M.R.; Jain, M.; Chandrasekaran, V.; Indumathi, E.; Soundrarajan, P.

    2008-01-01

    Thalassemia is a hereditary anemia resulting from defect in hemoglobinproduction. Beta thalassemia is due to impaired production. Beta thalassemiais due to impaired production of beta globin chains, leading to a relativeexcess of alpha globin chains. The term beta thalassemia minor is used todescribe heterozygotes, who carry one normal beta globin and one betathalassemic allele. The vast majority of these patients are asymptomatic.However, a variety of renal tubular abnormalities including hypercaliuria,hypomagnesemia with renal magnesium wasting, decreased tubular absorption ofphosphorous, hypouricemia with renal uric acid wasting, renal glycosuria andtubular proteinuria have been described even in patients with betathalassemia minor. We here in report a 24-year old patient who was found tohave thalassemia minor and nephrocalcinosis with evidence of renal tubulardysfunction. Investigations revealed normal renal function, hypercalciuria,reduced tubular reabsorption of phosphorous, hypomagnesemia and renalmagnesium wasting. Screening for aminoaciduria was found to be negative. Anacid loading test revealed normal urinary acidification. Ultrasonogram of theabdomen revealed nephrocalcinosis and splenomegaly. Detailed work up foranemia showed normal white cell and platelet count while peripheral smearshowed microcytic hypochromic anemia with few target cells. Hemoglobinelectrophoresis revealed hemoglobin A of 92%, hemoglobin A2 of 6.2% andhemoglobin F of 1.8% consistent with beta thalassemia minor. Her parentalscreening was normal. A diagnosis of beta thalassemia minor with renaltubular dysfunction was made and the patient was started on thiazidediuretics to reduce hypercalciuria and advised regular follow-up. (author)

  16. Experimental investigations and modeling of direct internal reforming of biogases in tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lanzini, A.; Leone, P.; Pieroni, M.; Santarelli, M. [Dipartimento di Energetica, Politecnico di Torino, Corso Duca degli Abruzzi 24, IT-10129, Torino (Italy); Beretta, D.; Ginocchio, S. [Centro Ricerca e Sviluppo, Edison S.p.a, Via La Pira 2, IT-10028 Trofarello, Torino (Italy)

    2011-10-15

    Biogas-fed Solid Oxide Fuel Cell (SOFC) systems can be considered as interesting integrated systems in the framework of distributed power generation. In particular, bio-methane and bio-hydrogen produced from anaerobic digestion of organic wastes represent renewable carbon-neutral fuels for high efficiency electrochemical generators. With such non-conventional mixtures fed to the anode of the SOFC, the interest lies in understanding the multi-physics phenomena there occurring and optimizing the geometric and operation parameters of the SOFC, while avoiding operating and fuel conditions that can lead to or accelerate degradation processes. In this study, an anode-supported (Ni-YSZ) tubular SOFC was considered; the tubular geometry enables a relatively easy separation of the air and fuel reactants and it allows one to evaluate the temperature field of the fuel gas inside the tube, which is strictly related to the electrochemical and heterogeneous chemical reactions occurring within the anode volume. The experiments have been designed to analyze the behavior of the cell under different load and fuel utilization (FU) conditions, providing efficiency maps for both fuels. The experimental results were used to validate a multi-physics model of the tubular cell. The model showed to be in good agreement with the experimental data, and was used to study the sensitive of some selected geometrical parameters modification over the cell performances. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. High Glucose Increases Metallothionein Expression in Renal Proximal Tubular Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Daisuke Ogawa

    2011-01-01

    Full Text Available Metallothionein (MT is an intracellular metal-binding, cysteine-rich protein, and is a potent antioxidant that protects cells and tissues from oxidative stress. Although the major isoforms MT-1 and -2 (MT-1/-2 are highly inducible in many tissues, the distribution and role of MT-1/-2 in diabetic nephropathy are poorly understood. In this study, diabetes was induced in adult male rats by streptozotocin, and renal tissues were stained with antibodies for MT-1/-2. MT-1/-2 expression was also evaluated in mProx24 cells, a mouse renal proximal tubular epithelial cell line, stimulated with high glucose medium and pretreated with the antioxidant vitamin E. MT-1/-2 expression was gradually and dramatically increased, mainly in the proximal tubular epithelial cells and to a lesser extent in the podocytes in diabetic rats, but was hardly observed in control rats. MT-1/-2 expression was also increased by high glucose stimulation in mProx24 cells. Because the induction of MT was suppressed by pretreatment with vitamin E, the expression of MT-1/-2 is induced, at least in part, by high glucose-induced oxidative stress. These observations suggest that MT-1/-2 is induced in renal proximal tubular epithelial cells as an antioxidant to protect the kidney from oxidative stress, and may offer a novel therapeutic target against diabetic nephropathy.

  18. Fabrication and characterization of an all-diamond tubular flow microelectrode for electroanalysis.

    Science.gov (United States)

    Hutton, Laura A; Vidotti, Marcio; Iacobini, James G; Kelly, Chris; Newton, Mark E; Unwin, Patrick R; Macpherson, Julie V

    2011-07-15

    The development of the first all-diamond hydrodynamic flow device for electroanalytical applications is described. Here alternate layers of intrinsic (insulating), conducting (heavily boron doped), and intrinsic polycrystalline diamond are grown to create a sandwich structure. By laser cutting a hole through the material, it is possible to produce a tubular flow ring electrode of a characteristic length defined by the thickness of the conducting layer (for these studies ∼90 μm). The inside of the tube can be polished to 17 ± 10 nm surface roughness using a diamond impregnanted wire resulting in a coplanar, smooth, all-diamond surface. The steady-state limiting current versus volume flow rate characteristics for the one electron oxidation of FcTMA(+) are in agreement with those expected for laminar flow in a tubular electrode geometry. For dopamine detection, it is shown that the combination of the reduced fouling properties of boron doped diamond, coupled with the flow geometry design where the products of electrolysis are washed away downstream of the electrode, completely eradicates fouling during electrolysis. This paves the way for incorporation of this flow design into online electroanalytical detection systems. Finally, the all diamond tubular flow electrode system described here provides a platform for future developments including the development of ultrathin ring electrodes, multiple apertures for increased current response, and multiple, individually addressable ring electrodes incorporated into the same flow tube.

  19. Connecting small ligands to generate large tubular metal-organic architectures

    International Nuclear Information System (INIS)

    Goforth, Andrea M.; Su, Cheng-Yong; Hipp, Rachael; Macquart, Rene B.; Smith, Mark D.; Loye, Hans-Conrad zur

    2005-01-01

    The new metal-organic framework materials, ZnF(Am 2 TAZ).solvents and ZnF(TAZ).solvents (Am 2 TAZ=3,5-diamino-1,2,4-triazole, TAZ=1,2,4-triazole), have been synthesized solvothermally and structurally characterized by either Rietveld refinement from powder XRD data or by single crystal X-ray diffraction. The three-dimensional structures of the compounds display open-ended, tubular channels, which are constituted of covalently bonded hexanuclear metallamacrocycles (Zn 6 F 6 (ligand) 6 ). The tubular channels are subsequently covalently joined into a honeycomb-like hexagonal array to generate the three-dimensional porous framework. In the case of ZnF(Am 2 TAZ).solvents, hydrophilic -NH 2 groups point into the channels, effectively reducing their inner diameter relative to ZnF(TAZ).solvents. The present compounds are isostructural to one another and to the previously reported ZnF(AmTAZ).solvents (AmTAZ=3-amino-1,2,4-triazole), illustrative of the fact that the internal size and chemical properties of the framework may be altered by modification of the small, heterocyclic ligand. In addition to demonstrating the ability to modify the basic framework, ZnF(TAZ).solvents and ZnF(Am 2 TAZ).solvents are two of the most thermally stable coordination frameworks known to date. - Graphical abstract: Top view of the open-ended, honeycomb tubular architecture of ZnF(Am 2 TAZ)

  20. Effect of benazepril on the transdifferentiation of renal tubular epithelial cells from diabetic rats.

    Science.gov (United States)

    Peng, Tao; Wang, Jie; Zhen, Junhui; Hu, Zhao; Yang, Xiangdong

    2014-07-01

    The aim of this study was to investigate the effect of benazepril on the transdifferentiation of renal tubular epithelial cells from diabetic rats. Thirty male Sprague-Dawley rats were included in the present study. Eight of the 30 rats were randomly selected and served as the normal control group (N group), while the remaining 22 rats, injected with streptozotocin (STZ), comprised the diabetic rat model. Rats with diabetes were randomly divided into the diabetic (DM group) and benazepril (B group) groups. The total course was conducted over 12 weeks. Blood glucose, body weight, kidney/body weight, 24-h urinary protein, serum creatinine and blood urea nitrogen were measured at the start and end of the study. We observed the tubulointerstitial pathological changes, and applied immunohistochemistry and western blotting to detect the expression of α-smooth muscle actin (α-SMA) in renal tissue. The levels of blood glucose, kidney/body weight, 24-h urinary protein, serum creatinine, blood urea nitrogen and tubulointerstitial damage index (TII) in the DM group were significantly higher than that in the N group (pbenazepril significantly reduced the expression of α-SMA in renal tubular epithelial cells obtained from diabetic rats, inhibited the transdifferentiation of renal tubular epithelial cells and played an important role in kidney protection.

  1. Modelling Particulate Removal in Tubular Wet Electrostatic Precipitators Using a Modified Drift Flux Model

    Directory of Open Access Journals (Sweden)

    S Ramechecandane

    2016-09-01

    Full Text Available Tubular electrostatic precipitators (ESP have been used in a number of chemical processing industries. The tubular ESPs have many advantages over conventional plate-plate and wire-plate ESPs. The present study is concerned with the numerical modeling of particulate removal in a tubular wet single-stage electrostatic precipitator (wESP. The geometric parameters of a model wESP and the corresponding inlet gas velocities for the wESP are chosen from available experimental data. In addition to the RNG k - ε model for the mean turbulent flow field inside the wESP, the Poisson equation for the electric field, the charge continuity equation and the concentration equation are solved sequentially to obtain a full-fledged solution to the problem under investigation. The proposed drift flux model is implemented in the opensource CFD code OpenFOAM®. The paper discusses the influence of the number of charges acquired by the particles and the corresponding inlet gas velocities on particle concentration distribution within the wESP. Two representative cases with monodispersed particles of 1 μm and 10 μm diameter are considered for the numerical analysis. It is seen from the present analysis that the number of units of charge on particles, the particle size and the inlet gas velocities play a vital role in determining the efficiency of electrostatic precipitation.

  2. Systematic bias in the measurement of water in oils by tubular oven evaporation and azeotropic distillation.

    Science.gov (United States)

    Margolis, S A; Mele, T

    2001-10-15

    Water in oil has been measured by tubular oven evaporation and by azeotropic distillation into a coulometric moisture analyzer. The results of these measurements were compared to the results obtained by volumetric titration of water in oil. The volumetric measurements were consistently higher than the measurements made by tubular oven evaporation or azeotropic distillation. A mass balance study was performed by volumetric Karl Fischer titration of the water in the oil that remained in the tubular oven and in the distillation apparatus. This study indicated that measurable amounts of water were not removed after exhaustive evaporation or distillation. The sum of the water removed by distillation from toluene and that remaining in the distillation chamber was equal to the amount of water measured in the oil by the volumetric method. The data are consistent with the existence of an oil-water azeotrope that does not release water upon evaporation at 160 degrees C or upon dissolution in toluene and distillation of the water-toluene azeotrope. These results were obtained for oils varying in viscosity from 8 to 850 m2/s, and the amount of water remaining associated with the oil appears to be dependent upon the composition of the oil and the method of analysis.

  3. Maximum production rate optimization for sulphuric acid decomposition process in tubular plug-flow reactor

    International Nuclear Information System (INIS)

    Wang, Chao; Chen, Lingen; Xia, Shaojun; Sun, Fengrui

    2016-01-01

    A sulphuric acid decomposition process in a tubular plug-flow reactor with fixed inlet flow rate and completely controllable exterior wall temperature profile and reactants pressure profile is studied in this paper by using finite-time thermodynamics. The maximum production rate of the aimed product SO 2 and the optimal exterior wall temperature profile and reactants pressure profile are obtained by using nonlinear programming method. Then the optimal reactor with the maximum production rate is compared with the reference reactor with linear exterior wall temperature profile and the optimal reactor with minimum entropy generation rate. The result shows that the production rate of SO 2 of optimal reactor with the maximum production rate has an increase of more than 7%. The optimization of temperature profile has little influence on the production rate while the optimization of reactants pressure profile can significantly increase the production rate. The results obtained may provide some guidelines for the design of real tubular reactors. - Highlights: • Sulphuric acid decomposition process in tubular plug-flow reactor is studied. • Fixed inlet flow rate and controllable temperature and pressure profiles are set. • Maximum production rate of aimed product SO 2 is obtained. • Corresponding optimal temperature and pressure profiles are derived. • Production rate of SO 2 of optimal reactor increases by 7%.

  4. Furosemide/Fludrocortisone Test and Clinical Parameters to Diagnose Incomplete Distal Renal Tubular Acidosis in Kidney Stone Formers.

    Science.gov (United States)

    Dhayat, Nasser A; Gradwell, Michael W; Pathare, Ganesh; Anderegg, Manuel; Schneider, Lisa; Luethi, David; Mattmann, Cedric; Moe, Orson W; Vogt, Bruno; Fuster, Daniel G

    2017-09-07

    Incomplete distal renal tubular acidosis is a well known cause of calcareous nephrolithiasis but the prevalence is unknown, mostly due to lack of accepted diagnostic tests and criteria. The ammonium chloride test is considered as gold standard for the diagnosis of incomplete distal renal tubular acidosis, but the furosemide/fludrocortisone test was recently proposed as an alternative. Because of the lack of rigorous comparative studies, the validity of the furosemide/fludrocortisone test in stone formers remains unknown. In addition, the performance of conventional, nonprovocative parameters in predicting incomplete distal renal tubular acidosis has not been studied. We conducted a prospective study in an unselected cohort of 170 stone formers that underwent sequential ammonium chloride and furosemide/fludrocortisone testing. Using the ammonium chloride test as gold standard, the prevalence of incomplete distal renal tubular acidosis was 8%. Sensitivity and specificity of the furosemide/fludrocortisone test were 77% and 85%, respectively, yielding a positive predictive value of 30% and a negative predictive value of 98%. Testing of several nonprovocative clinical parameters in the prediction of incomplete distal renal tubular acidosis revealed fasting morning urinary pH and plasma potassium as the most discriminative parameters. The combination of a fasting morning urinary threshold pH 3.8 mEq/L yielded a negative predictive value of 98% with a sensitivity of 85% and a specificity of 77% for the diagnosis of incomplete distal renal tubular acidosis. The furosemide/fludrocortisone test can be used for incomplete distal renal tubular acidosis screening in stone formers, but an abnormal furosemide/fludrocortisone test result needs confirmation by ammonium chloride testing. Our data furthermore indicate that incomplete distal renal tubular acidosis can reliably be excluded in stone formers by use of nonprovocative clinical parameters. Copyright © 2017 by the American

  5. The use of tubular subdermal and axial flaps in the correction of four cases of extensive lesions

    Directory of Open Access Journals (Sweden)

    Rafael Ricardo Huppes

    2017-10-01

    Full Text Available ABSTRACT: The most common skin lesions in small animals result from trauma, burns, or surgical resection of large tumors. Given the high importance of reconstructive surgery associated with tumors in small animals, this study reports four cases of reconstructive surgery using subcutaneous and axial tubular flaps in animals with neoplastic lesions. Subdermal and axial tubular flaps are healthy alternatives for reconstructing wounds caused by large tumor resection in areas with poor tissue elasticity.

  6. The use of tubular subdermal and axial flaps in the correction of four cases of extensive lesions

    OpenAIRE

    Rafael Ricardo Huppes; Josiane Morais Pazzini; Andrigo Barboza De Nardi²; Jorge Luiz Costa Castro; Cristiano Gomes; Arícia Gomes Sprada²; Ana Lúcia Pascolli²

    2017-01-01

    ABSTRACT: The most common skin lesions in small animals result from trauma, burns, or surgical resection of large tumors. Given the high importance of reconstructive surgery associated with tumors in small animals, this study reports four cases of reconstructive surgery using subcutaneous and axial tubular flaps in animals with neoplastic lesions. Subdermal and axial tubular flaps are healthy alternatives for reconstructing wounds caused by large tumor resection in areas with poor tissue elas...

  7. Variables process effect in the pure ferritic metal contribution deposited with an tubular metal-cored E111T5-K3 wire

    International Nuclear Information System (INIS)

    Svoboda, Hernan G; Ramini de Rissone, N.M; Surian, E; De Vedia, L

    2004-01-01

    The welding deposit performed with an ANSI-AWS E111T5-K3 type from the system C-Mn-Ni-Mo metal coring tubular welding, with a low slag generation was studied. Different operatives configurations with two thermal contribution levels (1 kJ and 1.5 kJ) and two types of protector gases (CO 2 and Ar-20%CO 2 ) at two welding position (under hand and ascendant vertical) were analyzed. The resulting pure contributor metal from the different process configurations was chemical, mechanically and structural characterized and the effect of the different process conditions was evaluated. The microstructure is fundamentally composed by FS(NA) and AF. For similar values of hardness and strength, good values of tenacity were observed and they show little variation with the process variables studied (AG)

  8. Synchronization of tubular pressure oscillations in interacting nephrons

    Energy Technology Data Exchange (ETDEWEB)

    Sosnovtseva, O.V. E-mail: olga@fysik.dtu.dk; Postnov, D.E.; Mosekilde, E.; Holstein-Rathlou, N.-H

    2003-01-01

    The pressure and flow regulation in the individual functional unit of the kidney (the nephron) tends to operate in an unstable regime. For normal rats, the regulation displays regular self-sustained oscillations, but for rats with high blood pressure the oscillations become chaotic. We explain the mechanisms responsible for this behavior and discuss the involved bifurcations. Experimental data show that neighboring nephrons adjust their pressure and flow regulation in accordance with one another. For rats with normal blood pressure, in-phase as well as anti-phase synchronization can be observed. For spontaneously hypertensive rats, indications of chaotic phase synchronization are found. Accounting for a hermodynamics as well as for a vascular coupling between nephrons that share a common interlobular artery, we present a model of the interaction of the pressure and flow regulations between adjacent nephrons. It is shown that this model, with physiologically realistic parameter values, can reproduce the different types of experimentally observed synchronization, including multistability and partial phase synchronization with respect to the slow and fast dynamics.

  9. Proximal Tubular Cannabinoid-1 Receptor Regulates Obesity-Induced CKD.

    Science.gov (United States)

    Udi, Shiran; Hinden, Liad; Earley, Brian; Drori, Adi; Reuveni, Noa; Hadar, Rivka; Cinar, Resat; Nemirovski, Alina; Tam, Joseph

    2017-12-01

    Obesity-related structural and functional changes in the kidney develop early in the course of obesity and occur independently of hypertension, diabetes, and dyslipidemia. Activating the renal cannabinoid-1 receptor (CB 1 R) induces nephropathy, whereas CB 1 R blockade improves kidney function. Whether these effects are mediated via a specific cell type within the kidney remains unknown. Here, we show that specific deletion of CB 1 R in the renal proximal tubule cells did not protect the mice from obesity, but markedly attenuated the obesity-induced lipid accumulation in the kidney and renal dysfunction, injury, inflammation, and fibrosis. These effects associated with increased activation of liver kinase B1 and the energy sensor AMP-activated protein kinase, as well as enhanced fatty acid β -oxidation. Collectively, these findings indicate that renal proximal tubule cell CB 1 R contributes to the pathogenesis of obesity-induced renal lipotoxicity and nephropathy by regulating the liver kinase B1/AMP-activated protein kinase signaling pathway. Copyright © 2017 by the American Society of Nephrology.

  10. Synchronization of tubular pressure oscillations in interacting nephrons

    International Nuclear Information System (INIS)

    Sosnovtseva, O.V.; Postnov, D.E.; Mosekilde, E.; Holstein-Rathlou, N.-H.

    2003-01-01

    The pressure and flow regulation in the individual functional unit of the kidney (the nephron) tends to operate in an unstable regime. For normal rats, the regulation displays regular self-sustained oscillations, but for rats with high blood pressure the oscillations become chaotic. We explain the mechanisms responsible for this behavior and discuss the involved bifurcations. Experimental data show that neighboring nephrons adjust their pressure and flow regulation in accordance with one another. For rats with normal blood pressure, in-phase as well as anti-phase synchronization can be observed. For spontaneously hypertensive rats, indications of chaotic phase synchronization are found. Accounting for a hermodynamics as well as for a vascular coupling between nephrons that share a common interlobular artery, we present a model of the interaction of the pressure and flow regulations between adjacent nephrons. It is shown that this model, with physiologically realistic parameter values, can reproduce the different types of experimentally observed synchronization, including multistability and partial phase synchronization with respect to the slow and fast dynamics

  11. Endocytosis of wheat germ agglutinin binding sites from the cell surface into a tubular endosomal network.

    Science.gov (United States)

    Raub, T J; Koroly, M J; Roberts, R M

    1990-04-01

    By using fluorescence and electron microscopy, the endocytic pathway encountered by cell surface components after they had bound wheat germ agglutinin (WGA) was visualized. The majority of these components are thought to consist of sialylated glycoproteins (HMWAG) that represent a subpopulation of the total cell surface proteins but most of the externally disposed plasma membrane proteins of the cell. Examination of semi-thin sections by medium- and high-voltage electron microscopy revealed the three-dimensional organization of vesicular and tubular endosomes. Binding of either fluorescein isothiocyanate-, horseradish peroxidase-, or ferritin-conjugated WGA to cells at 4 degrees C showed that the HMWAG were distributed uniformly over the cell surface. Warming of surface-labeled cells to 37 degrees C resulted in the endocytosis of WGA into peripheral endosomes via invagination of regions of both coated and uncoated membrane. The peripheral endosome appeared as isolated complexes comprising a vesicular element (300-400 nm diam.) surrounded by and continuous with tubular cisternae (45-60 nm diam.), which did not interconnect the endosomes. After 30 min or more label also became localized in a network of anastomosing tubules (45-60 nm diam.) that were located in the centrosomal region of the cell. Endocytosed WGA-HMWAG complexes did not become associated with cisternae of the Golgi apparatus, although tubular and vesicular endosomes were noted in the vicinity of the trans-Golgi region. The accumulation of WGA-HMWAG in the endosomes within the centrosomal region was inhibited when cells were incubated at 18 degrees C. None of these compartments contained acid phosphatase activity, a result that is consistent with other data that the HMWAG do not pass through lysosomes initially. The kinetics of labeling were consistent with the interpretation that recycling of most of the WGA binding surface glycoproteins occurred rapidly from early peripheral endosomes followed by the

  12. Monoanionic 99mTc-tricarbonyl-aminopolycarboxylate complexes with uncharged pendant groups: Radiosynthesis and evaluation as potential renal tubular tracers

    International Nuclear Information System (INIS)

    Lipowska, Malgorzata; Klenc, Jeffrey; Jarkas, Nashwa; Marzilli, Luigi G.; Taylor, Andrew T.

    2017-01-01

    Introduction: 99m Tc(CO) 3 -nitrilotriacetic acid, 99m Tc(CO) 3 (NTA), is a new renal tubular agent with pharmacokinetic properties comparable to those of 131 I-OIH but the clearance of 99m Tc(CO) 3 (NTA) and 131 I-OIH is still less than the clearance of PAH, the gold standard for the measurement of effective renal plasma flow. At physiological pH, dianionic 99m Tc(CO) 3 (NTA) has a mononegative inner metal-coordination sphere and a mononegative uncoordinated carboxyl group. To evaluate alternate synthetic approaches, we assessed the importance of an uncoordinated carboxyl group, long considered essential for tubular transport, by evaluating the pharmacokinetics of three analogs with the 99m Tc(CO) 3 (NTA) metal-coordination sphere but with uncharged pendant groups. Methods: 99m Tc(CO) 3 complexes with N-(2-acetamido)iminodiacetic acid (ADA), N-(2-hydroxyethyl)iminodiacetic acid (HDA) and N-(fluoroethyl)iminodiacetic acid (FEDA) were prepared using a tricarbonyl kit and isolated by HPLC. The pharmacokinetics were evaluated in Sprague–Dawley rats, with 131 I-OIH as an internal control; urine was analyzed for metabolites. Plasma protein binding and erythrocyte uptake were determined from the 10 min blood samples. Re(CO) 3 (FEDA), the analog of 99m Tc(CO) 3 (FEDA), was prepared and characterized. Results: 99m Tc(CO) 3 (ADA), 99m Tc(CO) 3 (HDA) and 99m Tc(CO) 3 (FEDA) were efficiently prepared as a single species with high radiochemical purities (>99%). These new monoanionic 99m Tc(CO) 3 tracers with uncharged dangling groups all showed rapid blood clearance and high specificity for renal excretion. Activity in the urine, as a percent of 131 I-OIH at 10 and 60 min, was 96% and 99% for ADA, 96% and 100% for HDA, and 100% and 99% for FEDA, respectively. Each new tracer was excreted unchanged in the urine. The Re(CO) 3 (FEDA) structure adds compelling evidence that such 99m Tc(CO) 3 (NTA) analogs have metal-coordination spheres identical to that of 99m Tc(CO) 3 (NTA

  13. Reorganization of the Endosomal System in Salmonella-Infected Cells: The Ultrastructure of Salmonella-Induced Tubular Compartments

    Science.gov (United States)

    Krieger, Viktoria; Liebl, David; Zhang, Yuying; Rajashekar, Roopa; Chlanda, Petr; Giesker, Katrin; Chikkaballi, Deepak; Hensel, Michael

    2014-01-01

    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. PMID:25254663

  14. CYP24A1 exacerbated activity during diabetes contributes to kidney tubular apoptosis via caspase-3 increased expression and activation.

    Directory of Open Access Journals (Sweden)

    Alexandre Tourigny

    Full Text Available Decreases in circulating 25,hydroxyl-vitamin D3 (25 OH D3 and 1,25,dihydroxyl-vitamin D3 (1,25 (OH2 D3 have been extensively documented in patients with type 2 diabetes. Nevertheless, the molecular reasons behind this drop, and whether it is a cause or an effect of disease progression is still poorly understood. With the skin and the liver, the kidney is one of the most important sites for vitamin D metabolism. Previous studies have also shown that CYP24A1 (an enzyme implicated in vitamin D metabolism, might play an important role in furthering the progression of kidney lesions during diabetic nephropathy. In this study we show a link between CYP24A1 increase and senescence followed by apoptosis induction in the renal proximal tubules of diabetic kidneys. We show that CYP24A1 expression was increased during diabetic nephropathy progression. This increase derived from protein kinase C activation and increased H(2O(2 cellular production. CYP24A1 increase had a major impact on cellular phenotype, by pushing cells into senescence, and later into apoptosis. Our data suggest that control of CYP24A1 increase during diabetes has a beneficial effect on senescence induction and caspase-3 increased expression. We concluded that diabetes induces an increase in CYP24A1 expression, destabilizing vitamin D metabolism in the renal proximal tubules, leading to cellular instability and apoptosis, and thereby accelerating tubular injury progression during diabetic nephropathy.

  15. Involvement of caspase-12-dependent apoptotic pathway in ionic radiocontrast urografin-induced renal tubular cell injury

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Cheng Tien [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Weng, Te I. [Department of Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Chen, Li Ping [Department of Dentistry, Chang Gang Memorial Hospital, Chang Gang University, Taoyuan, Taiwan (China); Chiang, Chih Kang [Department of Integrated Diagnostics and Therapeutics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Liu, Shing Hwa, E-mail: shinghwaliu@ntu.edu.tw [Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan (China); Department of Urology, National Taiwan University Hospital, Taipei, Taiwan (China)

    2013-01-01

    Contrast medium (CM) induces a direct toxic effect on renal tubular cells. This toxic effect subjects in the disorder of CM-induced nephropathy. Our previous work has demonstrated that CM shows to activate the endoplasmic reticulum (ER)-related adaptive unfolding protein response (UPR) activators. Glucose-regulated protein 78 (GRP78)/eukaryotic initiation factor 2α (eIF2α)-related pathways play a protective role during the urografin (an ionic CM)-induced renal tubular injury. However, the involvement of ER stress-related apoptotic signals in the urografin-induced renal tubular cell injury remains unclear. Here, we examined by the in vivo and in vitro experiments to explore whether ER stress-regulated pro-apoptotic activators participate in urografin-induced renal injury. Urografin induced renal tubular dilation, tubular cells detachment, and necrosis in the kidneys of rats. The tubular apoptosis, ER stress-related pro-apoptotic transcriptional factors, and kidney injury marker-1 (kim-1) were also conspicuously up-regulated in urografin-treated rats. Furthermore, treatment of normal rat kidney (NRK)-52E tubular cells with urografin augmented the expressions of activating transcription factor-6 (ATF-6), C/EBP homologous protein (CHOP), Bax, caspase-12, JNK, and inositol-requiring enzyme (IRE) 1 signals. Urografin-induced renal tubular cell apoptosis was not reversed by the inhibitors of ATF-6, JNK signals or CHOP siRNA transfection, but it could be partially reversed by the inhibitor of caspase-12. Taken together, the present results and our previous findings suggest that exposure of CM/urografin activates the ER stress-regulated survival- and apoptosis-related signaling pathways in renal tubular cells. Caspase-12-dependent apoptotic pathway may be partially involved in the urografin-induced nephropathy. -- Highlights: ► Ionic contrast medium-urografin induces renal tubular cell apoptosis. ► Urografin induces the ER stress-regulated survival and apoptosis

  16. Los primeros órganos tubulares en México

    Directory of Open Access Journals (Sweden)

    Guzmán Bravo, José Antonio

    2015-12-01

    Full Text Available This article deals with the logistic problems of transporting from Spain the earliest pipe organs to the wild geography of 16th century México and the assembly of these instruments. The typology of the monastic organs in Mexico and the type of Spanish Renaissance organ, as well as other keyboard instruments (major organs, realejos –portative organs–, monacordios –clavichords– and harpsichords are also reviewed. Missional workshops for instrument making, as well as minstrels, th Indian participation as builders and organists and wind instruments used in and out the Cathedral, are also under consideration. On the other hand, documents dealing with the description of organs, organists and organ builders in the old Cathedral of México, from 1530 until the first decades of the 17th century, when they moved to the new Cathedral, or the first great organist in América, don Manuel Rodríguez de Mesa and his interpretation of music by Cabezón, are different topics in this paper. Finally, the first half-register organ in America by Jerónimo de Aragón, the music by Correa de Arauxo, or the regulations for organist, singers and minstrels, complete the panorama of the present study.El presente artículo aborda cuestiones en torno a los problemas de transporte y armado de los instrumentos importados de España, la tipología de los órganos conventuales en México, del órgano renacentista español, los órganos grandes, realejos y otros instrumentos como monacordios, clavecímbalos, etc. Se hace un recuento de órganos, organistas y organeros en la antigua catedral de México a partir del año 1530 y hasta las primeras décadas del siglo XVII, antes de trasladarse el cabildo a la nueva catedral. Asimismo, se trata aquí de los constructores indígenas, de los Maestros de órgano y los ministriles, de la participación de los indios, así como de la enseñanza del órgano, categorías y salarios. También se hace mención al primer organista

  17. Significance of downregulation of renal organic cation transporter (SLC47A1 in cisplatin-induced proximal tubular injury

    Directory of Open Access Journals (Sweden)

    Mizuno T

    2015-07-01

    Full Text Available Tomohiro Mizuno,1–3 Waichi Sato,2,3 Kazuhiro Ishikawa,4 Yuki Terao,1 Kazuo Takahashi,2 Yukihiro Noda,5 Yukio Yuzawa,2 Tadashi Nagamatsu1 1Department of Analytical Pharmacology, Meijo University Faculty of Pharmacy, Nagoya, 2Department of Nephrology, School of Medicine, Fujita Health University, Toyoake, 3Department of Nephrology, Nagoya University School of Medicine, Nagoya, 4Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya, 5Division of Clinical Sciences and Neuropsychopharmacology, Meijo University Faculty of Pharmacy, Nagoya, Japan Background/aim: To elucidate the mechanism responsible for developing acute kidney injury in patients with diabetes mellitus, we also evaluated the issue of whether advanced glycation endproducts (AGEs influence the expressions of multi antimicrobial extrusion protein (MATE1/SLC47A1 in tubular cells. Materials and methods: To detect changing expression of MATE1/SLC47A1 in dose- and time-dependent manners, human proximal tubular epithelial cells were incubated with AGE-aggregated-human serum albumin. As a function assay for MATE1/SLC47A1, human proximal tubular epithelial cells were incubated with cisplatin or carboplatin. Results: On incubation with AGEs, the expressions of MATE1/SLC47A1 were decreased in tubular cells. In addition, the toxicities of cisplatin were increased in tubular cells that had been pretreated with AGEs. However, the toxicities of carboplatin were smaller than that of cisplatin in proximal tubular epithelial cells. Conclusion: The expression of the MATE1/SLC47A1 is decreased by AGEs, which increases the risk for proximal tubular injury. Keywords: advanced glycation endproducts, cisplatin, SLC47A1, diabetes mellitus, acute kidney injury

  18. Corrosion behavior of the tube - tubular plate joint zone in the presence of sediments

    International Nuclear Information System (INIS)

    Lucan, D.; Fulger, M.; Pirvan, I.; Cotolan, V.

    1997-01-01

    The corrosion is a very important problem which concerns the safe operation of steam generators. The predominant part of corrosion problems is related to the local concentration of aggressive species and/or to the impurities from the slow-flow regions, like those created by cracks in tube - tubular plate joint zones. The consequences of such local concentrations are very important and as such entail interest in the design and utilization of steam generators. This study presents the results of the corrosion tests performed under specific operation conditions of the secondary circuit in NPP (temperature, 260 o C; pressure, 5.1 MPa) on a crack simulating device made of carbon steel SA 508 cl.2 (forming the tubular plate) and Incoloy-800 (forming the tubes). The chemical medium of these tests was the following: solution of NaCl, 25g/l (pH=10.5); solution of NaCl, 50 g/l (pH=10.5); solution of NaCl, 75g/l (pH=10.5); solution of NaCl, 75g/l + solution of Na 2 SO 4 , 10 g/l (pH=10.5). The behavior of these two materials to corrosion was studied by metallographic investigations. The results are presented as microphotographs evidencing the occurrence of pitting corrosion first on material of the tubular plate, in the presence of medium particularly aggressive and on the material of the tubes. The aim of this study is to establish the corrosion mechanism as well as the formation of the oxide layer on the carbon steel in crack simulating devices. (authors)

  19. Distribution of IGF receptors in the plasma membrane of proximal tubular cells

    International Nuclear Information System (INIS)

    Hammerman, M.R.; Rogers, S.

    1987-01-01

    To characterize the distribution of receptors for insulin-like growth factors I and II (IGF I and II) in the plasma membrane of the renal proximal tubular cell, the authors measured binding of 125 I-labeled IGF I and 125 I-labeled IGF II to proximal tubular basolateral and brush-border membranes and characterized IGF I-stimulated phosphorylation of detergent-solubilized membranes. 125 I-IGF bound primarily to a 135,000 relative molecular weight (M r ) protein and IGF II to a 260,000 M r protein in isolated membranes. Binding of 125 I-IGF I was severalfold greater in basolateral than in brush-border membranes. IGF I-stimulated phosphorylation of the 92,000 M r β-subunit of its receptors could be demonstrated only in basolateral membranes. These findings are consistent with an asymmetrical distribution of receptors for IGF I in the plasma membrane of the renal proximal tubular cell, localization being primary on the basolateral side. In contrast, binding of 125 I-IGF II to isolated basolateral and brush-border membranes was equivalent, suggesting that receptors for this peptide are distributed more symmetrically in the plasma membrane. The findings suggest that the action of IGF I in proximal tubule are mediated via interaction of circulating peptide with specific receptors in the basolateral membrane. However, the findings established the potential for actions of IGF II to be exerted in proximal tubule via interaction with both basolateral and/or brush-border membrane receptors

  20. Analysis of mass transfer characteristics in a tubular membrane using CFD modeling.

    Science.gov (United States)

    Yang, Jixiang; Vedantam, Sreepriya; Spanjers, Henri; Nopens, Ingmar; van Lier, Jules B

    2012-10-01

    In contrast to the large amount of research into aerobic membrane bioreactors, little work has been reported on anaerobic membrane bioreactors (AMBRs). As to the application of membrane bioreactors, membrane fouling is a key issue. Membrane fouling generally occurs more seriously in AMBRs than in aerobic membrane bioreactors. However, membrane fouling could be managed through the application of suitable shear stress that can be introduced by the application of a two-phase flow. When the two-phase flow is applied in AMBRs, little is known about the mass transfer characteristics, which is of particular importance, in tubular membranes of AMBRs. In our present work, we have employed fluid dynamic modeling to analyze the mass transfer characteristics in the tubular membrane of a side stream AMBR in which, gas-lift two-phase flow was applied. The modeling indicated that the mass transfer capacity at the membrane surface at the noses of gas bubbles was higher than the mass transfer capacity at the tails of the bubbles, which is in contrast to the results when water instead of sludge is applied. At the given mass transfer rate, the filterability of the sludge was found to have a strong influence on the transmembrane pressure at a steady flux. In addition, the model also showed that the shear stress in the internal space of the tubular membrane was mainly around 20 Pa but could be as high as about 40 Pa due to gas bubble movements. Nonetheless, at these shear stresses a stable particle size distribution was found for sludge particles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. High temperature energy storage performances of methane reforming with carbon dioxide in a tubular packed reactor

    International Nuclear Information System (INIS)

    Lu, Jianfeng; Chen, Yuan; Ding, Jing; Wang, Weilong

    2016-01-01

    Highlights: • Energy storage of methane reforming in a tubular packed reactor is investigated. • Thermochemical storage efficiency approaches maximum at optimal temperature. • Sensible heat and heat loss play important roles in the energy storage system. • The reaction and energy storage models of methane reforming reactor are established. • The simulated methane conversion and energy storage efficiency fit with experiments. - Abstract: High temperature heat transfer and energy storage performances of methane reforming with carbon dioxide in tubular packed reactor are investigated under different operating conditions. Experimental results show that the methane reforming in tubular packed reactor can efficiently store high temperature thermal energy, and the sensible heat and heat loss besides thermochemical energy storage play important role in the total energy storage process. When the operating temperature is increased, the thermochemical storage efficiency first increases for methane conversion rising and then decreases for heat loss rising. As the operating temperate is 800 °C, the methane conversion is 79.6%, and the thermochemical storage efficiency and total energy efficiency can be higher than 47% and 70%. According to the experimental system, the flow and reaction model of methane reforming is established using the laminar finite-rate model and Arrhenius expression, and the simulated methane conversion and energy storage efficiency fit with experimental data. Along the flow direction, the fluid temperature in the catalyst bed first decreases because of the endothermic reaction and then increases for the heat transfer from reactor wall. As a conclusion, the maximum thermochemical storage efficiency will be obtained under optimal operating temperature and optimal flow rate, and the total energy efficiency can be increased by the increase of bed conductivity and decrease of heat loss coefficient.

  2. Use of a minimally invasive tubular retraction system for deep-seated tumors in pediatric patients.

    Science.gov (United States)

    Recinos, Pablo F; Raza, Shaan M; Jallo, George I; Recinos, Violette Renard

    2011-05-01

    Microsurgical removal is the preferred treatment for most deep-seated, intraaxial tumors in the pediatric population. The feasibility of surgery as an option has improved with advances in surgical technology and technique. Tubular retractors disperse retraction forces over a greater surface area than do conventional retractors, which can lower the risk of ischemic complications. The authors describe their experience utilizing a new tubular retractor system specifically designed for cranial applications in conjunction with frameless neuronavigation. The Vycor ViewSite retractor was used in 4 pediatric patients (ages 15 months and 9, 10, and 16 years) with deep-seated intraaxial tumors. The lesions included a papillary tumor of the pineal region, a low-grade astrocytoma in the occipital lobe, a dysembryoplastic neuroepithelial tumor arising from the basal ganglia, and an intraventricular low-grade glioma. The extent of white matter damage along the surgical trajectory (based on T2 or FLAIR and diffusion restriction/apparent diffusion coefficient signals) and the extent of resection were assessed on postoperative imaging. Satisfactory resection or biopsy was achieved in all patients. A comparison of pre- and postoperative MR imaging studies revealed evidence of white matter damage along the surgical trajectory in 1 patient. None of the patients demonstrated new neurological deficits postoperatively. Obtaining surgical access to deep-seated, intraaxial tumors is challenging. In this small series of pediatric patients, the combination of the ViewSite tubular retractor and frameless neuronavigation facilitated the surgical approach. The combination of these technologies adds to the armamentarium to safely approach tumors in deep locations.

  3. Cisplatin toxicity reduced in human cultured renal tubular cells by oxygen pretreatment.

    Science.gov (United States)

    Kaeidi, Ayat; Rasoulian, Bahram; Hajializadeh, Zahra; Pourkhodadad, Soheila; Rezaei, Maryam

    2013-01-01

    Cisplatin is an effective and widely used chemotherapy agent and its side effects, particularly nephrotoxicity, limit its usage and related platinum-based drugs. Cisplatin nephrotoxicity is mainly due to extremely increase in reactive oxygen species (ROS) generation leading to kidney tubular cell death. Preconditioning with oxidative stress has been demonstrated to stimulate the cellular adaptation to subsequent severe oxidative stress. Short term oxygen pre-exposure as a mild oxidative stress may enhance some endogenous defense mechanisms, so its effect on Cisplatin induced cell death was investigated in present research. We studied the effects of hyperoxic environment pre-exposure on Cisplatin toxicity in an in-vitro model of cultured human embryonic tubular epithelial cells (AD293). Viability of AD293 cells, as evaluated by MTT-assay, was affected by Cisplatin in a time (1-4 h) dependent model. Biochemical markers of cell apoptosis were evaluated using immunoblotting. Pretreatment with nearly pure oxygen (≥90%) for 2 h significantly reduced the level of cell damage. Activated caspase 3 and Bax/Bcl-2 ratio were significantly increased in Cisplatin-treated cells. Oxygen pretreatment inhibited caspase 3 activation and decreased Bax/Bcl-2 ratio. Oxygen pre-treatment itself not showed any cytotoxicity in exposure times up to 3 h. Our data indicate that hyperoxic preconditioning reduces Cisplatin toxicity in cultured human tubular epithelial cells. The exact mechanism of protection is unclear, though enhancement of some endogenous defense mechanisms and subsequently scavenging of free oxygen radicals may play an important role.

  4. Sol-gel open tubular ODS columns with reversed electroosmotic flow for capillary electrochromatography.

    Science.gov (United States)

    Hayes, J D; Malik, A

    2001-03-01

    Sol-gel chemistry was successfully used for the fabrication of open tubular columns with surface-bonded octadecylsilane (ODS) stationary-phase coating for capillary electrochromatography (OT-CEC). Following column preparations, a series of experiments were performed to investigate the performance of the sol-gel coated ODS columns in OT-CEC. The incorporation of N-octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride as one of the sol-gel precursors played an important role in the electrochromatographic performance of the prepared columns. This chemical reagent possesses a chromatographically favorable, bonded ODS moiety, in conjunction with three methoxy groups allowing for sol-gel reactivity. In addition, a positively charged nitrogen atom is present in the molecular structure of this reagent and provides a positively charged capillary surface responsible for the reversed electroosmotic flow (EOF) in the columns during CEC operation. Comparative studies involving the EOF within such sol-gel ODS coated and uncoated capillaries were performed using acetonitrile and methanol as the organic modifiers in the mobile phase. The use of a deactivating reagent, phenyldimethylsilane, in the sol-gel solution was evaluated. Efficiency values of over 400,000 theoretical plates per meter were achieved in CEC on a 64 cm x 25 microm i.d. sol-gel ODS open tubular column. Test mixtures of polycyclic aromatic hydrocarbons, benzene derivatives, and aromatic aldehydes and ketones were used to evaluate the CEC performances of both nondeactivated and deactivated open tubular sol-gel columns. The effects of mobile-phase organic modifier contents and pH on EOF in such columns were evaluated. The prepared sol-gel ODS columns are characterized by switchable electroosmotic flow. A pH value of approximately 8.5 was found correspond to the isoelectric point for the prepared sol-gel ODS coatings.

  5. Detection of Acute Tubular Necrosis Using Blood Oxygenation Level-Dependent (BOLD MRI

    Directory of Open Access Journals (Sweden)

    Frederic Bauer

    2017-12-01

    Full Text Available Background/Aims: To date, there is no imaging technique to assess tubular function in vivo. Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI measures tissue oxygenation based on the transverse relaxation rate (R2*. The present study investigates whether BOLD MRI can assess tubular function using a tubule-specific pharmacological maneuver. Methods: Cross sectional study with 28 participants including 9 subjects with ATN-induced acute kidney injury (AKI, 9 healthy controls, and 10 subjects with nephron sparing tumor resection (NSS with clamping of the renal artery serving as a model of ischemia/reperfusion (I/R-induced subclinical ATN (median clamping time 15 min, no significant decrease of eGFR, p=0.14. BOLD MRI was performed before and 5, 7, and 10 min after intravenous administration of 40 mg furosemide. Results: Urinary neutrophil gelatinase-associated lipocalin was significantly higher in ATN-induced AKI and NSS subjects than in healthy controls (p=0.03 and p=0.01, respectively. Before administration of furosemide, absolute medullary R2*, cortical R2*, and medullary/cortical R2* ratio did not significantly differ between ATN-induced AKI vs. healthy controls and between NSS-I/R vs. contralateral healthy kidneys (p>0.05 each. Furosemide led to a significant decrease in the medullary and cortical R2* of healthy subjects and NSS contralateral kidneys (p<0.05 each, whereas there was no significant change of R2* in ATN-induced AKI and the NSS-I/R kidneys (p>0.05 each. Conclusion: BOLD-MRI is able to detect even mild tubular injury but necessitates a tubule-specific pharmacological maneuver, e.g. blocking the Na+-K+-2Cl- transporter by furosemide.

  6. Design and analysis of tubular permanent magnet linear generator for small-scale wave energy converter

    Science.gov (United States)

    Kim, Jeong-Man; Koo, Min-Mo; Jeong, Jae-Hoon; Hong, Keyyong; Cho, Il-Hyoung; Choi, Jang-Young

    2017-05-01

    This paper reports the design and analysis of a tubular permanent magnet linear generator (TPMLG) for a small-scale wave-energy converter. The analytical field computation is performed by applying a magnetic vector potential and a 2-D analytical model to determine design parameters. Based on analytical solutions, parametric analysis is performed to meet the design specifications of a wave-energy converter (WEC). Then, 2-D FEA is employed to validate the analytical method. Finally, the experimental result confirms the predictions of the analytical and finite element analysis (FEA) methods under regular and irregular wave conditions.

  7. Sequential Injection Determination of D-Glucose by Chemiluminescence Using an Open Tubular Immobilised Enzyme Reactor

    DEFF Research Database (Denmark)

    Liu, Xuezhu; Hansen, Elo Harald

    1996-01-01

    A sequential injection analysis system is described that incorporates a nylon tubular reactor containing immobilised glucose oxidase, allowing determination of D-glucose by means of subsequent luminol chemiluminescence detection of the hydrogen peroxide generated in the enzymatic reaction....... The operating parameters were optimised by fractional factorial screening and response surface modelling. The linear range of D-glucose determination was 30-600 mu M, With a detection limit of 15 mu M using a photodiode detector. The sampling frequency was 54 h(-1). Lower LOD (0.5 mu M D-glucose) could...

  8. Lipid myopathy associated with renal tubular acidosis and spastic diplegia in two brothers.

    Science.gov (United States)

    Tung, Y C; Tsau, Y K; Chu, L W; Young, C; Shen, Y Z

    2001-07-01

    Lipid myopathy is a group of disorders involving mitochondrial fatty acid oxidation. We describe two brothers, 3 years 8 months old and 2 years 9 months old, respectively, with progressive spastic diplegia, developmental delay, failure to thrive, and chronic metabolic acidosis who had lipid myopathy and renal tubular acidosis. Brain magnetic resonance imaging revealed demyelinating changes in the periventricular white matter, which was compatible with spastic diplegia. These symptoms may be related to errors in fatty acid metabolism. Cerebral palsy had been misdiagnosed in both of these patients at another hospital. Therefore, for patients with late-onset and progressive spastic diplegia, detailed investigations for underlying diseases are warranted.

  9. Tubular Adenoma in the Indiana Pouch of a Patient With a History of Bladder Exstrophy

    Directory of Open Access Journals (Sweden)

    Madeleine G. Manka

    2015-09-01

    Full Text Available An increased risk of neoplasm has been noted when bowel segments are used for urinary diversion. Particularly true for ureterosigmoidostomy, colonic adenocarcinoma has rarely been reported following Indiana Pouch diversion. This report describes a 42-year-old woman with a history of bladder exstrophy who developed a polyp in her Indiana Pouch 24 years after its creation. The polyp, found incidentally, was a tubular adenoma with high-grade dysplasia. Due to its malignant potential, the polyp was resected with preservation of the Indiana Pouch. This case highlights the need for lifetime surveillance in urinary reservoir patients who received diversions at a young age.

  10. Synthesis of carbon nanostructures by the pyrolysis of wood sawdust in a tubular reactor

    Directory of Open Access Journals (Sweden)

    Maria G. Sebag Bernd

    2017-04-01

    Full Text Available Carbon nanostructures were produced by wood sawdust pyrolysis. The results obtained revealed that the thermodynamic simulations (FactSage were successful to predict the best reaction conditions for the synthesis of carbon, and potentially carbon fibers and nanotubes production. Graphite formation was indicated by XRD study, and by thermal analysis which presented the carbon oxidation range. The morphology of the samples (SEM/TEM analysis showed carbon nanotubes/nanofibers varying in size and thickness, with defects and flaws. The tubular reactor was considered to be an economic and environmental correct way to nanomaterials growing, with the simultaneous generation of hydrogen and lower pollutant gas emissions.

  11. Proximal renal tubular injury in rats sub-chronically exposed to low fluoride concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Cárdenas-González, Mariana C.; Del Razo, Luz M. [Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D. F., México (Mexico); Barrera-Chimal, Jonatan [Unidad de Fisiología Molecular, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México and Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México, D. F., México (Mexico); Jacobo-Estrada, Tania [Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D. F., México (Mexico); López-Bayghen, Esther [Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D. F., México (Mexico); and others

    2013-11-01

    Fluoride is usually found in groundwater at a very wide range of concentration between 0.5 and 25 ppm. At present, few studies have assessed the renal effects of fluoride at environmentally relevant concentrations. Furthermore, most of these studies have used insensitive and nonspecific biomarkers of kidney injury. The aim of this study was to use early and sensitive biomarkers to evaluate kidney injury after fluoride exposure to environmentally relevant concentrations. Recently weaned male Wistar rats were exposed to low (15 ppm) and high (50 ppm) fluoride concentrations in drinking water for a period of 40 days. At the end of the exposure period, kidney injury biomarkers were measured in urine and renal mRNA expression levels were assessed by real time RT-PCR. Our results showed that the urinary kidney injury molecule (Kim-1), clusterin (Clu), osteopontin (OPN) and heat shock protein 72 excretion rate significantly increased in the group exposed to the high fluoride concentration. Accordingly, fluoride exposure increased renal Kim-1, Clu and OPN mRNA expression levels. Moreover, there was a significant dose-dependent increase in urinary β-2-microglobulin and cystatin-C excretion rate. Additionally, a tendency towards a dose dependent increase of tubular damage in the histopathological light microscopy findings confirmed the preferential impact of fluoride on the tubular structure. All of these changes occurred at early stages in which, the renal function was not altered. In conclusion using early and sensitive biomarkers of kidney injury, we were able to found proximal tubular alterations in rats sub-chronically exposed to fluoride. - Highlights: • Exposure to low concentrations of fluoride induced proximal tubular injury • Increase in urinary Kim-1, Clu, OPN and Hsp72 in 50 ppm fluoride-exposed group • Increase in urinary B2M and CysC in 15 and 50 ppm fluoride-exposed groups • Fluoride exposure increased renal Kim, Clu and OPN mRNA expression levels.

  12. Evaluation of (o)-[77Br]bromohippuran as renal tubular function agent

    International Nuclear Information System (INIS)

    Aswegen, A. van; Roodt, J.P.; Pieters, H.; Herbst, C.P.; Otto, A.C.; Loetter, M.G.; Minnaar, P.C.; Haasbroek, F.J.

    1985-01-01

    (o)-[ 77 Br]bromohippuran (BHIP) was developed as renal tubular function agent due to its favourable chemical and physical properties and compared to (o)-[ 131 I]iodohippuran (IHIP). Renograms obtained from baboons were compared and absorbed radiation dose calculations performed. Although BHIP showed a delayed kidney uptake and washout pattern, good kidney clearance of the radionuclide was obtained after 30 min. Radiation dose values for BHIP were markedly lower than for IHIP indicating that larger activities of BHIP could be administered to increase counting statistics. BHIP imaging in normal volunteers did however not substantiate the favourable behaviour obtained in the primate. (author)

  13. Solitary eccrine syringofibroadenoma: a case report showing papillary tubular adenoma-like features

    Directory of Open Access Journals (Sweden)

    Toshiyuki Yamamoto

    2016-10-01

    Full Text Available We herein describe a case showing eccrine syringofibroadenoma occurred on the dorsum of the right foot of a 46-year-old Japanese female. Histopathologic examination revealed anastomosing cords and strands of cuboidal epithelial cells extending from the epidermis to the upper dermis, with a number of well-defined ducts suggesting eccrine ductal origin. In addition, there were papillary tubular adenoma-like ductal structures lined by a few rows of epithelial cells with papillary projections into the lumen surrounded by fibrous stroma in the mid-dermis. It is of note that various histologic features showing different differentiation were seen in a single lesion of eccrine syringofibroadenoma.

  14. Performance improvement of the circular tubular PEMFC by using different architectures and number of layers

    International Nuclear Information System (INIS)

    Mohammadi-Ahmar, Akbar; Osanloo, Behzad; Solati, Ali; Ghasemi, Jalal

    2016-01-01

    Highlights: • A full three-dimensional model was developed for cylindrical PEMFC. • CFD study on reactants distribution, current density and final power was performed. • Five cylindrical configurations were investigated (CP, C2C, C4C, C6C and C8C). - Abstract: The effects of arrangement and number of Membrane, Catalyst layer (CL) and Gas Diffusion layer (GDL) is investigated in present study. A full three-dimensional model was developed for tubular shaped PEMFC and the distribution of reactant concentration along anode and cathode channels, current density, power consumption and production were studied through computational Fluid dynamics (CFD). In order to do so, five arrangements of the tubular-shaped PEMFC namely: circular peripheral (CP), circular with two channels (C2C), circular with four channels (C4C), circular with six channels (C6C) and circular with eight channels (C8C) are presented. Comparison was made for new arrangements of layers, for the same active area and input mass flow in the anode and cathode. The results of polarization curve and power density shows that via increasing the number of layers, and thereby reducing the length of the fuel cell, more reactants are consumed along the tubular-shaped PEMFC. Among the five new arrangements, the CP case due to having high flow velocity for the same flow rate, has lower consumption along the channel and demonstrates undesirable results. Also in the dual-channel case (C2C) the core of the reacting flow is far from the reaction location (i.e. CL) therefor showed the lowest consumption and thus lowest power density. Whereas the eight-channel (C8C) configuration because of the appropriate distance between Membrane, CL and GDL layers and the core of the flow, increases the power output and reduces the cost, simultaneously due to shortest length in comparison to other cases. The results of present study can be employed for the manufacturing of new tubular-shaped PEMFC.

  15. Tubular wells perforation manual for investigation and training of Guarani Aquifer System

    International Nuclear Information System (INIS)

    2007-01-01

    The Environmental protection and sustainable development of the Aquifer Guarani System project is a initiative by Argentina, Brasil, Paraguay y Uruguay with the aim to raise the knowledge, legal and institutional sustainable management from 2003-2008 period. The Guarani consortium integrated by Tahal Engineers Ltda.(Israel), SEINCO SRL. (Uruguay), Hidrocontrol S:A:(Paraguay), Arcadis Hidroambiente S.A. (Argentina) have shown in Tubular wells perforation for investigation and training of Guarani Aquifer System manual their first product. This Manual includes technical especifications focused in Guarani Aquifer System harmessing building

  16. Device for filling tubular electrode plates for lead batteries. Vorrichtung zum Fuellen von Roehrchenelektrodenplatten fuer Bleiakkumulatoren

    Energy Technology Data Exchange (ETDEWEB)

    Barth, P.U.; Kubis, C.; Weber, H.J.; Wiepen, R.

    1984-11-22

    The device applies the vibration principle and according to the invention it uses a filling cassette for accommodating tubular electrode plates. The filling cassette has a filling funnel and is suspended with its vibration drive by springs. The vibration drive consists either of two out-of-balance motors, which are rigidly connected to the lower frame of the cassette, and have opposite directions of rotation, or of one out-of-balance motor, which is connected to a joint below the frame of the cassette.

  17. Device for filling tubular electrode plates for lead batteries. [German patent

    Energy Technology Data Exchange (ETDEWEB)

    Barth, P.U.; Kubis, C.; Weber, H.J.; Wiepen, R.

    1979-02-01

    The device applies the vibration principle and according to the invention it uses a filling cassette for accommodating tubular electrode plates. The filling cassette has a filling funnel and is suspended with its vibration drive by springs. The vibration drive consists either of two out-of-balance motors, which are rigidly connected to the lower frame of the cassette, and have opposite directions of rotation, or of one out-of-balance motor, which is connected to a joint below the frame of the cassette.

  18. Tubular microjets: Fabrication, factors affecting the motion and mechanism of propulsion

    Science.gov (United States)

    Parmar, Jemish; Vilela, Diana; Sanchez, Samuel

    2016-11-01

    Artificial micro- and nano-swimmers are interesting systems for both fundamental understandings of swimming at low Reynolds numbers and for their promising applications in many fields, such as environmental and biomedical fields. Different architectures of self-propelled systems present various propulsion mechanisms. Among them, tubular microjets are widely used for different applications. Here, we briefly describe the fabrication of microjets by rolling up thin film and electrodeposition techniques and the principles behind these processes. Different parameters affecting the motion of microjets and existing theoretical models about microjet propulsion are discussed.

  19. A micropuncture study of proximal tubular transport of lithium during osmotic diuresis

    DEFF Research Database (Denmark)

    Leyssac, P P; Holstein-Rathlou, N H; Skøtt, P

    1990-01-01

    Lithium and sodium are normally reabsorbed in parallel with water by the renal proximal tubule whereby their tubular fluid-to-plasma concentration ratios (TF/P) remain close to unity throughout the proximal convoluted segment. During osmotic diuresis, the late proximal (TF/P)Na is known to decrease....... The present experiments were undertaken to study whether the late proximal TF/P for Li decreases like that of Na during osmotic diuresis. Data were obtained in a control period (C) and in two successive periods during mannitol diuresis (P1, P2). Glomerular filtration rate decreased gradually during osmotic...

  20. Automation of Hessian-Based Tubularity Measure Response Function in 3D Biomedical Images

    OpenAIRE

    Dzyubak, Oleksandr P.; Ritman, Erik L.

    2011-01-01

    The blood vessels and nerve trees consist of tubular objects interconnected into a complex tree- or web-like structure that has a range of structural scale 5 μm diameter capillaries to 3 cm aorta. This large-scale range presents two major problems; one is just making the measurements, and the other is the exponential increase of component numbers with decreasing scale. With the remarkable increase in the volume imaged by, and resolution of, modern day 3D imagers, it is almost impossible to ma...

  1. Preliminary investigation of the performance of a single tubular combustor at pressure up to 12 atmospheres

    Science.gov (United States)

    Wear, Jerrold D; Butze, Helmut F

    1954-01-01

    The effects of combustor operation at conditions representative of those encountered in high pressure-ratio turbojet engines or at high flight speeds on carbon deposition, exhaust smoke, and combustion efficiency were studied in a single tubular combustor. Carbon deposition and smoke formation tests were conducted over a range of combustor-inlet pressures from 33 to 173 pounds per square inch absolute and combustor reference velocities from 78 to 143 feet per second. Combustion efficiency tests were conducted over a range of pressures from 58 to 117 pounds per square inch absolute and velocities from 89 to 172 feet per second.

  2. Folded tubular photometer for atmospheric measurements of NO2 and NO

    Directory of Open Access Journals (Sweden)

    J. W. Birks

    2018-05-01

    Full Text Available We describe and characterize a modular folded tubular photometer for making direct measurements of the concentrations of nitrogen dioxide (NO2 and specify how this method could be extended to measure other pollutants such as sulfur dioxide (SO2, ozone (O3, and black carbon particulate matter. Direct absorbance measurements using this photometer can be made across the spectral range from the ultraviolet (UV to the near infrared. The absorbance cell makes use of modular components (tubular detection cells and mirror cubes that allow construction of path lengths of up to 2 m or more while maintaining low cell volumes. The long path lengths and low cell volumes enable sensitive detection of ambient air pollutants down to low part-per-billion levels for gas species and aerosol extinctions down to 1 Mm−1, corresponding to  ∼  0.1 µg m−3 for black carbon particulates. Pressure equalization throughout the stages of the absorbance measurement is shown to be critical to accurate measurements of analyte concentrations. The present paper describes the application of this photometer to direct measurements of nitrogen dioxide (NO2 and the incorporation of design features that also enable measurement of nitric oxide (NO in the same instrument. Excellent agreement for ambient measurements along an urban roadside was found for both NO2 and NO measured by the folded tubular photometer compared to existing standard techniques. Compared to commonly used methods for measurements of NOx species, the advantages of this approach include (1 an absolute quantification for NO2 based on the Beer–Lambert law, thereby greatly reducing the frequency at which calibrations are required; (2 the direct measurement of NO2 concentration without prior conversion to NO as is required for the commonly used chemiluminescence method; (3 the use of modular components that allow construction of absorbance detection cells of varying lengths for extending the

  3. Cyclic process for producing methane in a tubular reactor with effective heat removal

    Science.gov (United States)

    Frost, Albert C.; Yang, Chang-Lee

    1986-01-01

    Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

  4. Performance of a vanadium redox flow battery with tubular cell design

    Science.gov (United States)

    Ressel, Simon; Laube, Armin; Fischer, Simon; Chica, Antonio; Flower, Thomas; Struckmann, Thorsten

    2017-07-01

    We present a vanadium redox flow battery with a tubular cell design which shall lead to a reduction of cell manufacturing costs and the realization of cell stacks with reduced shunt current losses. Charge/discharge cycling and polarization curve measurements are performed to characterize the single test cell performance. A maximum current density of 70 mAcm-2 and power density of 142 Wl-1 (per cell volume) is achieved and Ohmic overpotential is identified as the dominant portion of the total cell overpotential. Cycling displays Coulomb efficiencies of ≈95% and energy efficiencies of ≈55%. During 113 h of operation a stable Ohmic cell resistance is observed.

  5. Folded tubular photometer for atmospheric measurements of NO2 and NO

    Science.gov (United States)

    Birks, John W.; Andersen, Peter C.; Williford, Craig J.; Turnipseed, Andrew A.; Strunk, Stanley E.; Ennis, Christine A.; Mattson, Erick

    2018-05-01

    We describe and characterize a modular folded tubular photometer for making direct measurements of the concentrations of nitrogen dioxide (NO2) and specify how this method could be extended to measure other pollutants such as sulfur dioxide (SO2), ozone (O3), and black carbon particulate matter. Direct absorbance measurements using this photometer can be made across the spectral range from the ultraviolet (UV) to the near infrared. The absorbance cell makes use of modular components (tubular detection cells and mirror cubes) that allow construction of path lengths of up to 2 m or more while maintaining low cell volumes. The long path lengths and low cell volumes enable sensitive detection of ambient air pollutants down to low part-per-billion levels for gas species and aerosol extinctions down to 1 Mm-1, corresponding to ˜ 0.1 µg m-3 for black carbon particulates. Pressure equalization throughout the stages of the absorbance measurement is shown to be critical to accurate measurements of analyte concentrations. The present paper describes the application of this photometer to direct measurements of nitrogen dioxide (NO2) and the incorporation of design features that also enable measurement of nitric oxide (NO) in the same instrument. Excellent agreement for ambient measurements along an urban roadside was found for both NO2 and NO measured by the folded tubular photometer compared to existing standard techniques. Compared to commonly used methods for measurements of NOx species, the advantages of this approach include (1) an absolute quantification for NO2 based on the Beer-Lambert law, thereby greatly reducing the frequency at which calibrations are required; (2) the direct measurement of NO2 concentration without prior conversion to NO as is required for the commonly used chemiluminescence method; (3) the use of modular components that allow construction of absorbance detection cells of varying lengths for extending the dynamic range of concentrations that can

  6. Process to repair a steam generator tube by inserting a tubular sleeve and the associated sleeve

    International Nuclear Information System (INIS)

    Gaudin, J.P.

    1986-01-01

    The tubular sleeve is introduced in the tube and is mechanically expanded inside the tube plate, and is diametrally expanded at its upper part within the tube and outside the tube plate. Tightness is ensured by brazing the end part of the sleeve within the tube. The end part of the sleeve is brazed by melting of brazing metal previously applied to the outer surface of the sleeve of its end region. The invention applies more particularly to steam generators of pressurized water nuclear reactors [fr

  7. A comparison of integral block and tubular interacting fuel element concepts for low enrichment HTR

    Energy Technology Data Exchange (ETDEWEB)

    Desoisa, J A

    1972-04-15

    The tubular interacting fuel element has to date been the favoured U.K. high temperature reactor design. Recent attempts to lower fuel costs and the progress of the Fort St. Vrain reactor has focussed attention on alternative designs, and in particular on the attractive design simplicity of the integral block concept. The aim of this investigation is to compare the merits of both concepts from fuel cycle cost and thermal performance viewpoints and to determine whether optimization of the integral block concept leads to changes in the current design values of (a) fuel density, (b) Nc/Nu, and/or (c) mean discharge irradiation within the framework of present design limits.

  8. Preparation of β-cyclodextrin-gold nanoparticles modified open tubular column for capillary electrochromatographic separation of chiral drugs.

    Science.gov (United States)

    Zhou, Li; Jiang, Shenmeng; Zhang, Xue; Fang, Linlin; Guo, Xingjie

    2018-04-01

    In this paper, β-cyclodextrin (β-CD) modified gold nanoparticles (AuNPs) coated open tubular column (OT column) was prepared for capillary electrochromatography. The open tubular column was constructed through self-assembly of gold nanoparticles on 3-mercaptopropyl-trimethoxysilane (MPTMS) prederivatized capillary and subsequent modification of thiols β-cyclodextrin (SH-β-CD). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet visible spectroscopy were carried out to characterize the prepared open tubular column and synthesized gold nanoparticles. By comparing different coating times of gold nanoparticles and thiols β-cyclodextrin, we got the optimal conditions for preparing the open tubular column. Also, the separation parameters were optimized including buffer pH, buffer concentration and applied voltage. Separation effectiveness of open tubular column was verified by the separation of four pairs of drug enantiomers including bifonazole, fexofenadine, omeprazole and lansoprazole, and satisfactory separation results were achieved for these analytes studied. In addition, the column showed good stability and repeatability. The relative standard deviation values less than 5% were obtained through intra-day, inter-day, and column-to-column investigations. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Characterization of Chiral Carbonaceous Nanotubes Prepared from Four Coiled Tubular 4,4'-biphenylene-silica Nanoribbons

    Directory of Open Access Journals (Sweden)

    Shuwei Lin

    2014-04-01

    Full Text Available Four dipeptides derived from phenylalanine were synthesized, which can self-assemble into twisted nanoribbon in deionized water. The handedness of the organic self-assemblies was controlled by the chirality of the phenylalanine at the terminals. Coiled 4,4'-biphenylene bridged polybissilsesquioxane tubular nanoribbons were prepared using the organic self-assemblies as the templates. The circular dichroism spectra indicated that the biphenylene rings preferred to twist in one-handedness within the walls of the samples. After carbonization and removal of silica, single-handed coiled carbonaceous tubular nanoribbons were obtained. The Raman spectra indicated that the carbon was amorphous. The diffuse reflectance circular dichroism spectra indicated the tubular carbonaceous nanoribbons exhibited optical activity.

  10. An Interactive Tool for Outdoor Computer Controlled Cultivation of Microalgae in a Tubular Photobioreactor System

    Directory of Open Access Journals (Sweden)

    Raquel Dormido

    2014-03-01

    Full Text Available This paper describes an interactive virtual laboratory for experimenting with an outdoor tubular photobioreactor (henceforth PBR for short. This virtual laboratory it makes possible to: (a accurately reproduce the structure of a real plant (the PBR designed and built by the Department of Chemical Engineering of the University of Almería, Spain; (b simulate a generic tubular PBR by changing the PBR geometry; (c simulate the effects of changing different operating parameters such as the conditions of the culture (pH, biomass concentration, dissolved O2, inyected CO2, etc.; (d simulate the PBR in its environmental context; it is possible to change the geographic location of the system or the solar irradiation profile; (e apply different control strategies to adjust different variables such as the CO2 injection, culture circulation rate or culture temperature in order to maximize the biomass production; (f simulate the harvesting. In this way, users can learn in an intuitive way how productivity is affected by any change in the design. It facilitates the learning of how to manipulate essential variables for microalgae growth to design an optimal PBR. The simulator has been developed with Easy Java Simulations, a freeware open-source tool developed in Java, specifically designed for the creation of interactive dynamic simulations.

  11. Intracellular kinases mediate increased translation and secretion of netrin-1 from renal tubular epithelial cells.

    Directory of Open Access Journals (Sweden)

    Calpurnia Jayakumar

    Full Text Available BACKGROUND: Netrin-1 is a laminin-related secreted protein, is highly induced after tissue injury, and may serve as a marker of injury. However, the regulation of netrin-1 production is not unknown. Current study was carried out in mouse and mouse kidney cell line (TKPTS to determine the signaling pathways that regulate netrin-1 production in response to injury. METHODS AND PRINCIPAL FINDINGS: Ischemia reperfusion injury of the kidney was induced in mice by clamping renal pedicle for 30 minutes. Cellular stress was induced in mouse proximal tubular epithelial cell line by treating with pervanadate, cisplatin, lipopolysaccharide, glucose or hypoxia followed by reoxygenation. Netrin-1 expression was quantified by real time RT-PCR and protein production was quantified using an ELISA kit. Cellular stress induced a large increase in netrin-1 production without increase in transcription of netrin-1 gene. Mitogen activated protein kinase, ERK mediates the drug induced netrin-1 mRNA translation increase without altering mRNA stability. CONCLUSION: Our results suggest that netrin-1 expression is suppressed at the translational level and MAPK activation leads to rapid translation of netrin-1 mRNA in the kidney tubular epithelial cells.

  12. Modeling and analysis of mover gaps in tubular moving-magnet linear oscillating motors

    Directory of Open Access Journals (Sweden)

    Xuesong LUO

    2018-05-01

    Full Text Available A tubular moving-magnet linear oscillating motor (TMMLOM has merits of high efficiency and excellent dynamic capability. To enhance the thrust performance, quasi-Halbach permanent magnet (PM arrays are arranged on its mover in the application of a linear electro-hydrostatic actuator in more electric aircraft. The arrays are assembled by several individual segments, which lead to gaps between them inevitably. To investigate the effects of the gaps on the radial magnetic flux density and the machine thrust in this paper, an analytical model is built considering both axial and radial gaps. The model is validated by finite element simulations and experimental results. Distributions of the magnetic flux are described in condition of different sizes of radial and axial gaps. Besides, the output force is also discussed in normal and end windings. Finally, the model has demonstrated that both kinds of gaps have a negative effect on the thrust, and the linear motor is more sensitive to radial ones. Keywords: Air-gap flux density, Linear motor, Mover gaps, Quasi-Halbach array, Thrust output, Tubular moving-magnet linear oscillating motor (TMMLOM

  13. Reversal of Proximal Renal Tubular Dysfunction after Nucleotide Analogue Withdrawal in Chronic Hepatitis B

    Directory of Open Access Journals (Sweden)

    Abhasnee Sobhonslidsuk

    2017-01-01

    Full Text Available Aims. Proximal renal tubular dysfunction (PRTD is an infrequent complication after nucleotide analogue therapy. We evaluated the outcomes of PRTD and nephrotoxicity after nucleotide analogue withdrawal in chronic hepatitis B (CHB. Methods. A longitudinal follow-up study was performed in patients with PRTD after nucleotide analogue discontinuation. Serum and urine were collected at baseline and every 3 months for one year. The fractional excretion of phosphate (PO4, uric acid (UA, and potassium and tubular maximal reabsorption rate of PO4 to glomerular filtration rate (TmPO4/GFR were calculated. Renal losses were defined based on the criteria of substance losses. Subclinical PRTD and overt PRTD were diagnosed when 2 and ≥3 criteria were identified. Results. Eight subclinical and eight overt PRTD patients were enrolled. After nucleotide analogue withdrawal, there were overall improvements in GFR, serum PO4, and UA. Renal loss of PO4, UA, protein, and β2-microglobulin reduced over time. At one year, complete reversal of PRTD was seen in 13 patients (81.2%. Improvements in PRTD were seen in all but one patient. Conclusion. One year after nucleotide analogue withdrawal, PRTD was resolved in most patients. Changes in TmPO4/GFR, urinary protein, and β2-microglobulin indicate that urinary biomarkers may represent an early sign of PRTD recovery.

  14. Intracellular Kinases Mediate Increased Translation and Secretion of Netrin-1 from Renal Tubular Epithelial Cells

    Science.gov (United States)

    Jayakumar, Calpurnia; Mohamed, Riyaz; Ranganathan, Punithavathi Vilapakkam; Ramesh, Ganesan

    2011-01-01

    Background Netrin-1 is a laminin-related secreted protein, is highly induced after tissue injury, and may serve as a marker of injury. However, the regulation of netrin-1 production is not unknown. Current study was carried out in mouse and mouse kidney cell line (TKPTS) to determine the signaling pathways that regulate netrin-1 production in response to injury. Methods and Principal Findings Ischemia reperfusion injury of the kidney was induced in mice by clamping renal pedicle for 30 minutes. Cellular stress was induced in mouse proximal tubular epithelial cell line by treating with pervanadate, cisplatin, lipopolysaccharide, glucose or hypoxia followed by reoxygenation. Netrin-1 expression was quantified by real time RT-PCR and protein production was quantified using an ELISA kit. Cellular stress induced a large increase in netrin-1 production without increase in transcription of netrin-1 gene. Mitogen activated protein kinase, ERK mediates the drug induced netrin-1 mRNA translation increase without altering mRNA stability. Conclusion Our results suggest that netrin-1 expression is suppressed at the translational level and MAPK activation leads to rapid translation of netrin-1 mRNA in the kidney tubular epithelial cells. PMID:22046354

  15. Template-based fluoroethylenepropylene piezoelectrets with tubular channels for transducer applications

    Science.gov (United States)

    Altafim, Ruy Alberto Pisani; Qiu, Xunlin; Wirges, Werner; Gerhard, Reimund; Altafim, Ruy Alberto Corrêa; Basso, Heitor Cury; Jenninger, Werner; Wagner, Joachim

    2009-07-01

    We describe the concept, the fabrication, and the most relevant properties of a piezoelectric-polymer system: Two fluoroethylenepropylene (FEP) films with good electret properties are laminated around a specifically designed and prepared polytetrafluoroethylene (PTFE) template at 300 °C. After removing the PTFE template, a two-layer FEP film with open tubular channels is obtained. For electric charging, the two-layer FEP system is subjected to a high electric field. The resulting dielectric barrier discharges inside the tubular channels yield a ferroelectret with high piezoelectricity. d33 coefficients of up to 160 pC/N have already been achieved on the ferroelectret films. After charging at suitable elevated temperatures, the piezoelectricity is stable at temperatures of at least 130 °C. Advantages of the transducer films include ease of fabrication at laboratory or industrial scales, a wide range of possible geometrical and processing parameters, straightforward control of the uniformity of the polymer system, flexibility, and versatility of the soft ferroelectrets, and a large potential for device applications e.g., in the areas of biomedicine, communications, production engineering, sensor systems, environmental monitoring, etc.

  16. A class of dynamin-like GTPases involved in the generation of the tubular ER network

    Science.gov (United States)

    Hu, Junjie; Shibata, Yoko; Zhu, Peng-Peng; Voss, Christiane; Rismanchi, Neggy; Prinz, William A.; Rapoport, Tom A.; Blackstone, Craig

    2009-01-01

    The endoplasmic reticulum (ER) consists of tubules that are shaped by the reticulons and DP1/Yop1p, but how the tubules form an interconnected network is unknown. Here, we show that mammalian atlastins, which are dynamin-like, integral membrane GTPases, interact with the tubule-shaping proteins. The atlastins localize to the tubular ER and are required for proper network formation in vivo and in vitro. Depletion of the atlastins or overexpression of dominant-negative forms inhibits tubule interconnections. The Sey1p GTPase in S. cerevisiae is likely a functional ortholog of the atlastins; it shares the same signature motifs and membrane topology and interacts genetically and physically with the tubule-shaping proteins. Cells simultaneously lacking Sey1p and a tubule-shaping protein have ER morphology defects. These results indicate that formation of the tubular ER network depends on conserved dynamin-like GTPases. Since atlastin-1 mutations cause a common form of hereditary spastic paraplegia, we suggest ER shaping defects as a novel neuropathogenic mechanism. PMID:19665976

  17. Chirality of Single-Handed Twisted Titania Tubular Nanoribbons Prepared Through Sol-gel Transcription.

    Science.gov (United States)

    Wang, Sibing; Zhang, Chuanyong; Li, Yi; Li, Baozong; Yang, Yonggang

    2015-08-01

    Single-handed twisted titania tubular nanoribbons were prepared through sol-gel transcription using a pair of enantiomers. Handedness was controlled by that of the template. The obtained samples were characterized using field-emission electron microscopy, transmission electron microscopy, diffuse reflectance circular dichroism (DRCD), and X-ray diffraction. The DRCD spectra indicated that the titania nanotubes exhibit optical activity. Although the tubular structure was destroyed after being calcined at 700 °C for 2.0 h, DRCD signals were still identified. However, the DRCD signals disappeared after being calcined at 1000 °C for 2.0 h. The optical activity of titania was proposed to be due to chiral defects. Previous results showed that straight titania tubes could be used as asymmetric autocatalysts, indicating that titania exhibit chirality at the angstrom level. Herein, it was found that they also exhibit DRCD signals, indicating that there are no obvious relationships between morphology at the nano level and chirality at the angstrom level. The nanotube chirality should originate from the chiral defects on the nanotube inner surface. The Fourier transform infrared spectra indicated that the chirality of the titania was transferred from the gelators through the hydrogen bonding between N-H and Ti-OH. © 2015 Wiley Periodicals, Inc.

  18. Evaluation of cell viability and functionality in vessel-like bioprintable cell-laden tubular channels.

    Science.gov (United States)

    Yu, Yin; Zhang, Yahui; Martin, James A; Ozbolat, Ibrahim T

    2013-09-01

    Organ printing is a novel concept recently introduced in developing artificial three-dimensional organs to bridge the gap between transplantation needs and organ shortage. One of the major challenges is inclusion of blood-vessellike channels between layers to support cell viability, postprinting functionality in terms of nutrient transport, and waste removal. In this research, we developed a novel and effective method to print tubular channels encapsulating cells in alginate to mimic the natural vascular system. An experimental investigation into the influence on cartilage progenitor cell (CPCs) survival, and the function of printing parameters during and after the printing process were presented. CPC functionality was evaluated by checking tissue-specific genetic marker expression and extracellular matrix production. Our results demonstrated the capability of direct fabrication of cell-laden tubular channels by our newly designed coaxial nozzle assembly and revealed that the bioprinting process could induce quantifiable cell death due to changes in dispensing pressure, coaxial nozzle geometry, and biomaterial concentration. Cells were able to recover during incubation, as well as to undergo differentiation with high-level cartilage-associated gene expression. These findings may not only help optimize our system but also can be applied to biomanufacturing of 3D functional cellular tissue engineering constructs for various organ systems.

  19. Effect of Processing Parameters on Pore Structure and Thickness of Anodic Aluminum Oxide (AAO) Tubular Membranes

    Science.gov (United States)

    Belwalkar, A.; Grasing, E.; Huang, Z.; Misiolek, W.Z.

    2008-01-01

    Nanoporous anodic aluminum oxide (AAO) tubular membranes were fabricated from aluminum alloy tubes in sulfuric and oxalic acid electrolytes using a two-step anodization process. The membranes were investigated for characteristics such as pore size, interpore distance and thickness by varying applied voltage and electrolyte concentration. Morphology of the membranes was examined using light optical and scanning electron microscopy and characterized using ImageJ software. Results showed that membranes having narrow pore size and uniform pore distribution with parallel channel arrays were obtained. The pore sizes were ranging from 14 to 24 nm and the wall thicknesses as high as 76 µm. It was found that the pore size increased in direct proportion with the applied voltage and inversely with the electrolyte concentration while the interpore distance increased linearly with the applied voltage. It was also observed that increase in acid concentration increased tubular membrane wall thickness that improved mechanical handling. By using anodic alumina technology, robust ceramic tubes with uniformly distributed pore-structure and parallel nano-channels of lengths and sizes practical for industrial applications were reliably produced in quantity. PMID:19578471

  20. Untethered Recyclable Tubular Actuators with Versatile Locomotion for Soft Continuum Robots.

    Science.gov (United States)

    Qian, Xiaojie; Chen, Qiaomei; Yang, Yang; Xu, Yanshuang; Li, Zhen; Wang, Zhenhua; Wu, Yahe; Wei, Yen; Ji, Yan

    2018-05-27

    Stimuli-responsive materials offer a distinguished platform to build tether-free compact soft robots, which can combine sensing and actuation without a linked power supply. In the past, tubular soft robots have to be made by multiple components with various internal channels or complex cavities assembled together. Moreover, robust processing, complex locomotion, simple structure, and easy recyclability represent major challenges in this area. Here, it is shown that those challenges can be tackled by liquid crystalline elastomers with allyl sulfide functional groups. The light-controlled exchange reaction between allyl sulfide groups allows flexible processing of tubular soft robots/actuators, which does not need any assisting materials. Complex locomotion demonstrated here includes reversible simultaneous bending and elongation; reversible diameter expansion; and omnidirectional bending via remote infrared light control. Different modes of actuation can be programmed into the same tube without the routine assembly of multiple tubes as used in the past. In addition, the exchange reaction also makes it possible to use the same single tube repeatedly to perform different functions by erasing and reprogramming. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.